WorldWideScience

Sample records for chemical properties

  1. Chemical properties of mendelevium

    Energy Technology Data Exchange (ETDEWEB)

    Hulet, E.K.

    1980-11-01

    Even with the most intense ion beams and the largest available quantities of target isotope, about 10/sup 6/ atoms at a time is all the Md that can be produced for chemical studies. This lack of sufficient sample size coupled with the very short lifetimes of the few atoms produced has severely restricted the gathering and the broadness of our knowledge concerning the properties of Md and the heavier elements. To illustrate, the literature contains a mere eleven references to the chemical studies of Md, and none of these deal with bulk properties associated with the element bound in solid phases. Some of these findings are: Md was found to be more volatile than other actinide metals which lead to the belief that it is divalent in the metallic state; separation of Md from the other actinides can be accomplished either by reduction of Md/sup 3 +/ to the divalent state or by chromatographic separations with Md remaining in the tripositive state; extraction of Md/sup 2 +/ with bis(2-ethylhexyl)phosphoric acid is much poorer than the extraction of the neighboring tripositive actinides; attempts to oxidize Md/sup 3 +/ with sodium bismuthate failed to show any evidence for Md/sup 4 +/; reduction potential of Md/sup 3 +/ was found to be close to -0.1 volt; Md/sup 3 +/ can be reduced to Md(Hg) by sodium amalgams and by electrolysis; the electrochemical behavior of Md is very similar to that of Fm and can be summarized in the equation, Md/sup 2 +/ + 2e/sup -/ = Md(Hg) and E/sup 0/ = -1.50 V.; and Md cannot be reduced to a monovalent ion with Sm/sup 2 +/.

  2. 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.

  3. Properties and applications of chemically functionalized graphene

    International Nuclear Information System (INIS)

    The vast and yet largely unexplored family of graphene materials has great potential for future electronic devices with novel functionalities. The ability to engineer the electrical and optical properties in graphene by chemically functionalizing it with a molecule or adatom is widening considerably the potential applications targeted by graphene. Indeed, functionalized graphene has been found to be the best known transparent conductor or a wide gap semiconductor. At the same time, understanding the mechanisms driving the functionalization of graphene with hydrogen is proving to be of fundamental interest for energy storage devices. Here we discuss recent advances on the properties and applications of chemically functionalized graphene. (topical review)

  4. Mechanical and chemical properties of sewage pipes

    OpenAIRE

    Ł. Wierzbicki; M. Szymiczek

    2012-01-01

    Purpose: The purpose of this paper was to evaluate the compatibility of the physico-chemical properties of sewage pipes with the requirements of PN – EN ISO 1401-01: Plastics piping systems for non-pressure underground drainage and sewerage. This article is based on a research carried out for the water supply company. The article presents the results of mechanical and chemical testing of four pipes of unplasticized polyvinyl chloride and one pipe of polypropylene. All the test pipes were app...

  5. Some negative chemical properties of acid soils

    OpenAIRE

    SVETLANA ANTIC-MLADENOVIC; SRDJAN BLAGOJEVIC; MIRJANA KRESOVIC; MIODRAG JAKOVLJEVIC

    2005-01-01

    Some important chemical properties of various samples of two types of acid soil fromWestern Serbia (pseudogley and brown forest) are presented in this paper.Mobile Al was found in elevated and toxic quantities (10–30 mg/100 g) in the more acid samples of pseudogley soil. All samples of brown forest soil were very acid and the quantities ofmobile Al were in the range from 12.8 to 90.0mg/100 g. In a selected number of pseudogley soils, the influence of pH and other soil properties on the minera...

  6. Engineering electrical properties of graphene: chemical approaches

    Science.gov (United States)

    Kim, Yong-Jin; Kim, Yuna; Novoselov, Konstantin; Hong, Byung Hee

    2015-12-01

    To ensure the high performance of graphene-based devices, it is necessary to engineer the electrical properties of graphene with enhanced conductivity, controlled work function, opened or closed bandgaps, etc. This can be performed by various non-covalent chemical approaches, including molecular adsorption, substrate-induced doping, polymerization on graphene, deposition of metallic thin films or nanoparticles, etc. In addition, covalent approaches such as the substitution of carbon atoms with boron or nitrogen and the functionalization with hydrogen or fluorine are useful to tune the bandgaps more efficiently, with better uniformity and stability. In this review, representative examples of chemically engineered graphene and its device applications will be reviewed, and remaining challenges will be discussed.

  7. Octenidine dihydrochloride: chemical characteristics and antimicrobial properties.

    Science.gov (United States)

    Assadian, Ojan

    2016-03-01

    The empiric use of antibiotics is being restricted due to the spread of antimicrobial resistance. However, topical antiseptics are less likely to induce resistance, owing to their unspecific mode of action and the high concentrations in which they can be used. One such antiseptic, octenidine dihydrochloride (OCT), can be used either prophylactically or therapeutically on the skin, mucosa and wounds. Evidence to support its use comes from in-vitro, animal and clinical studies on its safety, tolerability and efficacy. This article summarises the physical, chemical and antimicrobial properties of OCT in the context of wound care. PMID:26949863

  8. Chemical properties of peat used in balneology

    Science.gov (United States)

    Szajdak, L.; Hładoń, T.

    2009-04-01

    The physiological activity of peats is observed in human peat-bath therapy and in the promotion of growth in some plants. Balneological peat as an ecologically clean and natural substance is perceived as being more 'human friendly' than synthetic compounds. Poland has a long tradition of using balneological peat for therapeutic purposes. Balneological peat reveals a physical effect by altering temperature and biochemical effects through biologically active substances. It is mainly used for the treatment of rheumatic diseases that are quite common in Poland. Peat represents natural product. Physico-chemical properties of peat in particular surface-active, sorption and ion exchanges, defining their biological function, depend mainly on the chemical composition and molecular structure of humic substances representing the major constituent of organic soil (peat). The carbon of organic matter of peats is composed of 10 to 20% carbohydrates, primarily of microbial origin; 20% nitrogen-containing constituents, such as amino acids and amino sugars; 10 to 20% aliphatic fatty acids, alkanes, etc.; with the rest of carbon being aromatic. For balneology peat should be highly decomposed (preferably H8), natural and clean. The content of humic acids should exceed 20% of dry weight, ash content will be less than 15 15% of dry weight, sulphur content less than 0.3% of dry weight and the amount of water more than 85%. It will not contain harmful bacteria and heavy metals. Humic substances (HS) of peat are known to be macromolecular polydisperse biphyllic systems including both hydrophobic domains (saturated hydrocarbon chains, aromatic structural units) and hydrophilic functional groups, i. e having amphiphilic character. Amphiphilic properties of FA are responsible for their solubility, viscosity, conformation, surfactant-like character and a variety of physicochemical properties of considerable biologically practical significance. The chemical composition of peats depends

  9. Chemical properties of antiepileptic drugs (AEDs).

    Science.gov (United States)

    Bialer, Meir

    2012-07-01

    Between 1990 and 2011 the following fifteen new antiepileptic drugs (AEDs) were approved: eslicarbazepine acetate, felbamate, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, pregabalin, retigabine, rufinamide, stiripentol, tiagabine, topiramate, vigabatrin, and zonisamide. These AEDs (except felbamate) offer appreciable advantages in terms of their favorable pharmacokinetics, improved tolerability and lower potential for drug interactions. All AEDs introduced after 1990 that are not second generation drugs (with the exception of vigabatrin and tiagabine) were developed empirically (sometimes serendipitously) utilizing mechanism-unbiased anticonvulsant animal models. The empirical nature of the discovery of new AEDs in the last three decades coupled with their multiple mechanisms of action explains their diverse chemical structures. The availability of old and new AEDs with various activity spectra and different tolerability profiles enables clinicians to better tailor drug choice to the characteristics of individual patients. With fifteen new AEDs having entered the market in the past 20years the antiepileptic market is crowded. Consequently, epilepsy alone is not attractive in 2011 to the pharmaceutical industry even though the clinical need of refractory epilepsy remains unmet. Due to this situation, future design of new AEDs must also have a potential in non-epileptic CNS disorders such as neuropathic pain, migraine prophylaxis and bipolar disorder or fibromyalgia as demonstrated by the sales revenues of pregabalin, topiramate and valproic acid. This review analyzes the effect that the emerging knowledge on the chemical properties of the old AEDs starting from phenobarbital (1912) has had on the design of subsequent AEDs and new therapeutics as well as the current approach to AED discovery. PMID:22210279

  10. Property Modelling for Applications in Chemical Product and Process Design

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    is missing, the atom connectivity based model is employed to predict the missing group interaction. In this way, a wide application range of the property modeling tool is ensured. Based on the property models, targeted computer-aided techniques have been developed for design and analysis of organic chemicals......, polymers, mixtures as well as separation processes. The presentation will highlight the framework (ICAS software) for property modeling, the property models and issues such as prediction accuracy, flexibility, maintenance and updating of the database. Also, application issues related to the use of property......Physical-chemical properties of pure chemicals and their mixtures play an important role in the design of chemicals based products and the processes that manufacture them. Although, the use of experimental data in design and analysis of chemicals based products and their processes is desirable...

  11. Thermodynamic and transport properties of gaseous tetrafluoromethane in chemical equilibrium

    Science.gov (United States)

    Hunt, J. L.; Boney, L. R.

    1973-01-01

    Equations and in computer code are presented for the thermodynamic and transport properties of gaseous, undissociated tetrafluoromethane (CF4) in chemical equilibrium. The computer code calculates the thermodynamic and transport properties of CF4 when given any two of five thermodynamic variables (entropy, temperature, volume, pressure, and enthalpy). Equilibrium thermodynamic and transport property data are tabulated and pressure-enthalpy diagrams are presented.

  12. Chemical Property in Heavy Ion Collisions

    Science.gov (United States)

    Kaneta, M.

    K-/K+ and bar{p}/p ratios measured in 158 A\\cdotGeV Pb + Pb collisions are shown as a function of centrality and transverse momentum (Pt). Little significant centrality dependence in neither K-/K+ nor bar{p}/p ratios are observed and they are almost constant as a function of Pt. The chemical freeze-out temperature Tch and the chemical potentials for both light and strange quarks (μq, μs) are extracted by comparing the present data with simple model predictions. The μq, μs and Tch from the NA44 are compared with those obtained from similar analysis of SPS S + A and AGS Si + A data. The chemical freeze-out temperature Tch in CERN energy is higher than thermal freeze-out temperature Tfo which is extracted from transverse momentum distribution of charged hadrons. In AGS energy Tch is close to Tfo.

  13. Coupled chemical oscillators and emergent system properties.

    Science.gov (United States)

    Epstein, Irving R

    2014-09-25

    We review recent work on a variety of systems, from the nanometre to the centimetre scale, including microemulsions, microfluidic droplet arrays, gels and flow reactors, in which chemical oscillators interact to generate novel spatiotemporal patterns and/or mechanical motion. PMID:24835430

  14. CET89 - CHEMICAL EQUILIBRIUM WITH TRANSPORT PROPERTIES, 1989

    Science.gov (United States)

    Mcbride, B.

    1994-01-01

    Scientists and engineers need chemical equilibrium composition data to calculate the theoretical thermodynamic properties of a chemical system. This information is essential in the design and analysis of equipment such as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical processing equipment. The substantial amount of numerical computation required to obtain equilibrium compositions and transport properties for complex chemical systems led scientists at NASA's Lewis Research Center to develop CET89, a program designed to calculate the thermodynamic and transport properties of these systems. CET89 is a general program which will calculate chemical equilibrium compositions and mixture properties for any chemical system with available thermodynamic data. Generally, mixtures may include condensed and gaseous products. CET89 performs the following operations: it 1) obtains chemical equilibrium compositions for assigned thermodynamic states, 2) calculates dilute-gas transport properties of complex chemical mixtures, 3) obtains Chapman-Jouguet detonation properties for gaseous species, 4) calculates incident and reflected shock properties in terms of assigned velocities, and 5) calculates theoretical rocket performance for both equilibrium and frozen compositions during expansion. The rocket performance function allows the option of assuming either a finite area or an infinite area combustor. CET89 accommodates problems involving up to 24 reactants, 20 elements, and 600 products (400 of which may be condensed). The program includes a library of thermodynamic and transport properties in the form of least squares coefficients for possible reaction products. It includes thermodynamic data for over 1300 gaseous and condensed species and transport data for 151 gases. The subroutines UTHERM and UTRAN convert thermodynamic and transport data to unformatted form for faster processing. The program conforms to the FORTRAN 77 standard, except for

  15. Sensory properties and chemical composition of Sharri cheese from Kosovo

    OpenAIRE

    Agim Rysha; Frane Delaš

    2014-01-01

    Food sensory properties, analyses and chemical composition are very important because they provide information about product quality and end-user acceptance or preferences. An assessment of sensory characteristics and chemical composition of mountain sheep and cow’s-milk cheese from shepherd’s huts and industrial manufacturers in Kosovo was carried out. Consumer-oriented tests using a 9 point hedonic scale were conducted in order to determine Sharri cheese acceptability. Chemical parameters (...

  16. A Chemical Properties Simulator to Support Integrated Environmental Modeling (proceeding)

    Science.gov (United States)

    Users of Integrated Environmental Modeling (IEM) systems are responsible for defining individual chemicals and their properties, a process that is time-consuming at best and overwhelming at worst, especially for new chemicals with new structures. A software tool is needed to allo...

  17. Study on scattering properties of tissues with hyperosmotic chemical agents

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Optical properties of biological tissue are variable due to the changes of micro-structures and scattering constituents after hyperosmotic chemical agents permeates into tissue. The changes of optical properties of biological tissue are due to the refractive indices matching between the scatterers with high refractive index and the ground substances, which reduce scattering of tissue. The main reasons are that permeated semipermeable chemical agents with higher refractive index than the ground substances of tissuemakes the refractive index of ground substances of tissue higher by the enhancement of the permeated concentration. We studied on the collimated transmittance changes of light penetrating biological tissue after the hyperosmotic chemical agents administrates with different concentration.

  18. Microbicidal properties and chemical composition of essential oils

    OpenAIRE

    Křůmal, K. (Kamil); Večeřa, Z. (Zbyněk)

    2014-01-01

    The microbicidal properties of 6 essential oils (EOs; Lavandula angustifolia, Cymbopogon nardus, Citrus aurantifolia, Juniperus communis, Myrtus communis and Cinnamomum zeylanicum ) for 17 microorganisms were determined using the vapour-agar contact method. The most effective EO (i.e. Lavandula angustifolia ) whose volatile components provided the sufficient microbicidal properties was chosen for detailed study of chemical composition.

  19. Characterization of Chemical and Mechanical Properties of Polymer Based Nanocomposites

    OpenAIRE

    Wafy, Tamer

    2013-01-01

    Characterization of Chemical and Mechanical Properties of Polymer Based NanocompositesThe University of ManchesterTamer Wafy Doctor of Philosophy17 January, 2013One of the most significant issues in nanocomposite performance is improving the dispersion of carbon nanotubes (CNTs) in thermosetting or thermoplastic polymers in order to gain good mechanical properties. Several studies have investigated the fabrication of nanocomposites based on carbon nanotubes and analysed properties, but there ...

  20. Role of fuel chemical properties on combustor radiative heat load

    Science.gov (United States)

    Rosfjord, T. J.

    1984-01-01

    In an attempt to rigorously study the fuel chemical property influence on combustor radiative heat load, UTRC has conducted an experimental program using 25 test fuels. The burner was a 12.7-cm dia cylindrical device fueled by a single pressure-atomizing injector. Fuel physical properties were de-emphasized by selecting injectors which produced highly-atomized, and hence rapidly-vaporizing sprays. The fuels were specified to cover the following wide ranges of chemical properties: hydrogen, 9.1 to 15- (wt) pct; total aromatics, 0 to 100 (vol) pct; and naphthalene, 0 to 30 (vol) pct. They included standard fuels, specialty products and fuel blends. Fuel naphthalene content exhibited the strongest influence on radiation of the chemical properties investigated. Smoke point was a good global indicator of radiation severity.

  1. Chemical identification and properties of element 112

    CERN Document Server

    Yakushev, A B; Zvára, I

    2002-01-01

    The second experiment on the chemical identification of element 112 performed at the FLNR (Dubna) is reported. Similar to the first test in 2000, the 2 mg/cm sup 2 sup n sup a sup t U target was bombarded with the 262-MeV sup 4 sup 8 Ca ions aiming at the production of sup 2 sup 8 sup 3 112, which as reported earlier decays by SF with a half-life of 3 min. The bombardment products recoiling from the target were thermalized in flowing helium and transported by the gas to detectors 25 m apart. Of all the heavy elements, the reaction products, only Hg, Rn and At were efficiently transported and thus selectively isolated. This time the beam dose was much higher (2.8 centre dot 10 sup 1 sup 8) and two different devices for detecting fission fragments and alpha particles were employed. The device used earlier was an assembly of sixteen PIPS detectors coated with Au to detect 'Hg-like' nuclides being adsorbed on Au at ambient temperature. The new one was a flow-through ionization chamber, 5000 cm sup 3 in volume, wh...

  2. Improving the electrical properties of graphene layers by chemical doping

    International Nuclear Information System (INIS)

    Although the electronic properties of graphene layers can be modulated by various doping techniques, most of doping methods cost degradation of structural uniqueness or electrical mobility. It is matter of huge concern to develop a technique to improve the electrical properties of graphene while sustaining its superior properties. Here, we report the modification of electrical properties of single- bi- and trilayer graphene by chemical reaction with potassium nitrate (KNO3) solution. Raman spectroscopy and electrical transport measurements showed the n-doping effect of graphene by KNO3. The effect was most dominant in single layer graphene, and the mobility of single layer graphene was improved by the factor of more than 3. The chemical doping by using KNO3 provides a facile approach to improve the electrical properties of graphene layers sustaining their unique characteristics. (paper)

  3. Sensory properties and chemical composition of Sharri cheese from Kosovo

    Directory of Open Access Journals (Sweden)

    Agim Rysha

    2014-11-01

    Full Text Available Food sensory properties, analyses and chemical composition are very important because they provide information about product quality and end-user acceptance or preferences. An assessment of sensory characteristics and chemical composition of mountain sheep and cow’s-milk cheese from shepherd’s huts and industrial manufacturers in Kosovo was carried out. Consumer-oriented tests using a 9 point hedonic scale were conducted in order to determine Sharri cheese acceptability. Chemical parameters (fat content, fat content of dry matter, acidity, protein, dry matter, mineral and water content and sodium chloride content of 45-day brine cheese samples were also analyzed. Chemical and sensory assessment demonstrated large property differences. A recommendation stems from the results showing that the standardization of both artisanal and industrial production of Sharri cheese is required.

  4. Branch structure of corona discharge: experimental simulation and chemical properties

    International Nuclear Information System (INIS)

    The branch structure of corona discharge has been investigated via C2H2 corona discharge. Carbon filament with excellent branch structure is formed in the discharge. This carbon filament offers a direct mimic of the branch structure of corona discharge. It provides a very useful way to study on the average energy, physical and chemical characteristics of corona discharge. On this basis, the chemical property of corona discharge for methane conversion is discussed. (authors)

  5. Nanodispersed Oxides-Plasma-Chemical Synthesis and Properties

    Institute of Scientific and Technical Information of China (English)

    Gheorghi VISSOKOV; Katerina ZAHARIEVA

    2007-01-01

    We discuss the plasma-chemical synthesis and the properties of transition metals oxides, Al2O3, SiO2, rare-earth oxides, oxides for ceramics and metal-ceramics, and oxides used as catalysts. Bearing in mind the indisputable advantages of using plasma-chemically synthesized nanodispersed oxides for the needs of various industrial fields, we set out to review the articles published in the past few years devoted to the problems of plasma-chemical synthesis and characterization of nanodispersed oxides.

  6. Evaluations of properties and review applications of some chemical dosimeters

    International Nuclear Information System (INIS)

    A chemical dosimeter is one of the most important methods used to measure radiation doses via a chemical reaction caused by the ionizing radiation. It is a system that measures the dose rate by chemical changes when it is exposed to ionizing radiation. This interaction produces changes in the chemical properties of the material that used as dosimeter as well as change in color. In all chemical dosimeters radiation induced chemical reaction produces new species, which its properties long lived enough to determine its quantity or the change in the initial system. This study discussed some different types of chemical dosimeters such as aqueous, gaseous and solid, the great consideration was given to aqueous systems because of their vital role in many applications. The dose rate of gamma cell was measured by using Fricke dosimeter found that dose rate about 0.909 Gy/sec while the theoretical dose rate was 0.910 Gy/sec, which confirms the suitability of Fricke dosimeter for this calibration. (Author)

  7. How forest fire affects the chemical properties of Andisols

    Science.gov (United States)

    Neris, Jonay; Hernández-Moreno, José Manuel; Tejedor, Marisa; Jiménez, Concepción

    2013-04-01

    Forest fires affect soil physical, chemical and mineralogical properties. However, the magnitude of these changes depends on both fire properties, such as the peak temperature reached and duration or depth achieved; and initial soil properties (soil type) as for example soil moisture, organic matter content or soil structure characteristics. Although many works have studied the effects of fire on the chemical properties of different soil types, its effects on Andisols properties have been omitted until now. Taking into account the high susceptibility to drying processes showed by the properties of Andisols affected by land use changes, it could be expected that the fire effects on their chemical properties may differ from those shown by other types of soil. In this study, the main chemical properties in addition to the specific andic properties of burned pine forest Andisols were compared to their unburned control. The chemical properties of ashes found after fire at the soil surface were also studied. The results show a slightly increase in EC and pH after the fire due mainly to the higher content of cations of the soil solution. Ashes derived from the vegetation and soil organic matter consumption by fire could be the main source of these elements in the soils after a fire, as they showed a high cation content. However, the rise in EC and pH is lower than the reported by most authors for other soil types. This behaviour could be related to the higher organic matter content of this soils, even after fire, and the buffering effect of organic compounds on the soil EC and pH changes after the fire. As other authors have shown, a decrease in both the total and active organic content after the fire was also observed as a result of the fire event. The specific andic properties of Andisols were also affected. The P retention of these soils slightly declines as a consequence of fire, while the content of short-range-order products was also modified, but no statistically

  8. EVALUATION OF CHEMICALS INCORPORATED WOOD FIBRE CEMENT MATRIX PROPERTIES

    Directory of Open Access Journals (Sweden)

    MST. SADIA MAHZABIN

    2013-08-01

    Full Text Available Wood fibre cement (WFC boards are well established commercially and widely used in many developed countries. The combination of the properties of two important materials, i.e., cement, and previously treated fibrous materials like wood or agricultural residues; which made up the board, contributed in the performance of the board as building material. In this work, the WFC matrix (WFCM samples are produced to determine the physical properties of WFCM such as the density and water absorption. The wood fibres are incorporated/treated with three different chemical additives; calcium formate (Ca(HCOO2, sodium silicate (Na2.SiO3 and magnesium chloride (MgCl2 prior to mixing with cement. The mechanical properties of the WFCM, with or without chemicals treatment of fibres, such as the compressive strength and flexural strength are evaluated. Three wood/cement ratios (50:50, 40:60, 30:70 are used and the percentages of water and accelerator were 80% and 3% based on the cement weight, respectively. Three moisture-conditioned samples; accelerated aging, dry and wet conditions are used for flexural test. The results reveal that the wood/cement ratio, chemical additives and moisture content had a marked influence on the physical and mechanical properties of the matrix. Finally, it has been shown that the 40:60 wood/cement ratio samples with prior chemicals treatment of the fibres that undergo accelerated aging conditioning achieve higher strength then dry and wet-conditioned boards.

  9. Composition and Thermodynamic Properties of Air in Chemical Equilibrium

    Science.gov (United States)

    Moeckel, W E; Weston, Kenneth C

    1958-01-01

    Charts have been prepared relating the thermodynamic properties of air in chemical equilibrium for temperatures to 15,000 degrees k and for pressures 10(-5) to 10 (plus 4) atmospheres. Also included are charts showing the composition of air, the isentropic exponent, and the speed of sound. These charts are based on thermodynamic data calculated by the National Bureau of Standards.

  10. Physical, chemical and electrochemical properties of pure and doped ceria

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Sammes, N.M.; Tompsett, G.A.

    2000-01-01

    This paper gives an extract of available data on the physical, chemical, electrochemical and mechanical properties of pure and doped ceria, predominantly in the temperature range from 200 to 1000 degrees C. Several areas are pointed out where further research is needed in order to make a better...

  11. Surface Chemical Properties of Colloids in Main Soils of China

    Institute of Scientific and Technical Information of China (English)

    MAYI-JIE; YUANCHAO-LIANG

    1991-01-01

    Surface chemical properties of soil colloids are the important factor affecting soil fertility and genesis.To provide scientific basis for soil genetic classification,promotion of soil fertility and reasonable fertilizqation,the specific surface area and electric charge of soil colloids in relation to clay minerals and organic matter are further discussed on the basis of the results obtained from the studies on surface chemical properties of soil colloids in five main soils of China.Results from the studies show that the effect of clay minerals and organic matter on the surface chemical properties of soil colloids is very complicated because the siloxane surface,hydrated oxide surface and organic matter surface do not exist separately,but they are always mixed together and influenced each other.The understanding of the relationship among clay minerals,organic matter and surface chemical properties of soil colloids depends upon further study of the relevant disciplines of soil science,especially the study on the mechanisms of organo-mineral complexes.

  12. Physico-chemical Properties of Marine Phospholipid Emulsions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.;

    2012-01-01

    of this study was to investigate the emulsifying properties of various commercial marine PL and the feasibility of using them to prepare stable emulsions prepared with or without addition of fish oil. In addition, this study also investigated the relationship between chemical composition of marine PL...

  13. Physico-chemical properties of probiotic yoghurt produced with transglutaminase

    Directory of Open Access Journals (Sweden)

    Milanović Spasenija D.

    2007-01-01

    Full Text Available The effect of different concentration of transglutaminase - TG (0.02%, 0.06% and 0.12% on physico-chemical properties of probiotic yoghurt was investigated. Two series of yoghurt were manufactured on a laboratory scale from pasteurised skim milk (0.1 % w/w fat. Series I was produced with TGase activation during a period of 2 h at 40°C, while series II was produced without enzyme activation. Then, the adequate quantities of TGase and probiotic starter culture ABT-4 (Chr. Hansen A/S Denmark were added. Chemical composition, physico-chemical properties (water holding capacity and whey separation and sensory characteristics of yoghurt samples were determined after production and during 5 days of storage. Addition of TGase to milk (direct or after activation for probiotic yoghurt manufacture improved its overall characteristics. Activation of TG in yoghurt production increases water holding capacity as well as decreases syneresis during the storage.

  14. Many Molecular Properties from One Kernel in Chemical Space

    CERN Document Server

    Ramakrishnan, Raghunathan

    2015-01-01

    We introduce property-independent kernels for machine learning modeling of arbitrarily many molecular properties. The kernels encode molecular structures for training sets of varying size, as well as similarity measures sufficiently diffuse in chemical space to sample over all training molecules. Corresponding molecular reference properties provided, they enable the instantaneous generation of ML models which can systematically be improved through the addition of more data. This idea is exemplified for single kernel based modeling of internal energy, enthalpy, free energy, heat capacity, polarizability, electronic spread, zero-point vibrational energy, energies of frontier orbitals, HOMO-LUMO gap, and the highest fundamental vibrational wavenumber. Models of these properties are trained and tested using 112 kilo organic molecules of similar size. Resulting models are discussed as well as the kernels' use for generating and using other property models.

  15. The diverse biological properties of the chemically inert noble gases.

    Science.gov (United States)

    Winkler, David A; Thornton, Aaron; Farjot, Géraldine; Katz, Ira

    2016-04-01

    The noble gases represent an intriguing scientific paradox. They are extremely inert chemically but display a remarkable spectrum of clinically useful biological properties. Despite a relative paucity of knowledge of their mechanisms of action, some of the noble gases have been used successfully in the clinic. Studies with xenon have suggested that the noble gases as a class may exhibit valuable biological properties such as anaesthesia; amelioration of ischemic damage; tissue protection prior to transplantation; analgesic properties; and a potentially wide range of other clinically useful effects. Xenon has been shown to be safe in humans, and has useful pharmacokinetic properties such as rapid onset, fast wash out etc. The main limitations in wider use are that: many of the fundamental biochemical studies are still lacking; the lighter noble gases are likely to manifest their properties only under hyperbaric conditions, impractical in surgery; and administration of xenon using convectional gaseous anaesthesia equipment is inefficient, making its use very expensive. There is nonetheless a significant body of published literature on the biochemical, pharmacological, and clinical properties of noble gases but no comprehensive reviews exist that summarize their properties and the existing knowledge of their models of action at the molecular (atomic) level. This review provides such an up-to-date summary of the extensive, useful biological properties of noble gases as drugs and prospects for wider application of these atoms. PMID:26896563

  16. β-Amyloid pathogenesis: Chemical properties versus cellular levels

    DEFF Research Database (Denmark)

    Tiwari, Manish Kumar; Kepp, Kasper Planeta

    2016-01-01

    , or aggregation propensities. Cytotoxicity correlates inversely with total Aβ42 (R2=0.65, P =.016) and Aβ42/Aβ40 ratios (R2=0.76, P=.005), i.e., chemical properties that increase Aβ42 also reduce toxicity. The complexity and heterogeneity of data reveal the need to understand these phenotypes better, e......Although genetic Aβ variants cause early-onset Alzheimer's disease, literature reports on Aβ properties are heterogeneous, obscuring molecular mechanisms, as illustrated by recent failures of Aβ-level targeting trials. Thus, we combined available data on Aβ levels and ratios, aggregation...

  17. Blending ionic liquids: how physico-chemical properties change.

    Science.gov (United States)

    Castiglione, Franca; Raos, Guido; Appetecchi, Giovanni Battista; Montanino, Maria; Passerini, Stefano; Moreno, Margherita; Famulari, Antonino; Mele, Andrea

    2010-02-28

    Ionic liquids offer the opportunity of tailoring their properties by changing the chemical structure of the cation and anion. Blending of two or more liquids adds a further dimension to this "chemical space". Here we present the results of a study of three binary and one ternary mixture of the ionic liquids formed by the N-butyl-N-methylpyrrolidinium cation with bis(trifluoromethanesulfonyl) imide, bis(pentafluoroethanesulfonyl) imide and (trifluoromethanesulfonyl)(nonafluorobutanesulfonyl) imide. We have collected viscosity and NMR-based data on ionxion correlations (NOE) and diffusion (DOSY). We also attempt to establish a quantitative correlation between mixture and the corresponding pure liquid properties. We find that the binary mixture containing the two very different anions has an intriguing and somewhat anomalous behaviour. PMID:20145843

  18. Ethyl coumarin-3-carboxylate: synthesis and chemical properties

    Directory of Open Access Journals (Sweden)

    Bakr F. Abdel-Wahab

    2014-03-01

    Full Text Available Ethyl coumarin-3-carboxylate occupies an important position in the organic synthesis and is used in production of biologically active compounds. Thus, the data published over the last few years on the methods of synthesis and chemical properties of ethyl coumarin-3-carboxylate are reviewed here for the first time. The reactions were classified as coumarin ring reactions and ester group reactions, and some of these reactions have been applied successfully to the synthesis of biologically and industrially important compounds.

  19. Effects of chemical dispersants on oil physical properties and dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Khelifa, A.; Fingas, M.; Hollebone, B.P.; Brown, C.E. [Environment Canada, Ottawa, ON (Canada). ; Pjontek, D. [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering

    2007-07-01

    Laboratory and field testing have shown that the dispersion of oil spilled in water is influenced by chemical dispersants via the modification of the interfacial properties of the oil, such as oil-brine interfacial tension (IFT). This study focused on new laboratory experiments that measured the effects on the physical properties and dispersion of oil, with particular reference to the effects of chemical dispersants on IFT and oil viscosity and the subsequent effects on oil droplet formation. Experiments were conducted at 15 degrees C using Arabian Medium, Alaska North Slope and South Louisiana crude and Corexit 9500 and Corexit 9527 chemical dispersants. The dispersants were denser than the 3 oils. The effect of IFT reduction on oil dispersion was measured and showed substantial reduction in the size and enhancement of the concentration of oil droplets in the water column. It was shown that the brine-oil IFT associated with the 3 crudes reduced to less than 3.6 mN/m with the application of the chemical dispersants, even at a low dispersant-to-oil ratio (DOR) value of 1:200. The use of chemical dispersants increased the viscosity of the dispersant-oil mixture up to 40 per cent over the neat crude oil. It was shown that for each mixing condition, an optimum value of DOR exists that provides for maximal dispersant effectiveness. The IFT reaches maximum reduction at optimum DOR. It was suggested that oil spill modelling can be improved with further study of IFT reduction with DOR and variations of critical micelle concentration with the type and solubility of chemical dispersant, oil type and oil to water ratio. 13 refs., 3 tabs., 7 figs.

  20. Swelling Properties of Expansive Soils Treated with Chemicals and Flyash

    Directory of Open Access Journals (Sweden)

    G Radhakrishnan

    2016-08-01

    Full Text Available Expansive soil shows recurrent volume changes with the changes moisture content, causing serious problems to the civil engineering structures such as road pavements resting on them. Several attempts are being made all over the world to control the swell shrink behavior of expansive soils. Flexible Pavements constructed on these soil shows signs of damage continuously during the service life of the pavement causes an increase in the maintenance costs. Numerous methods are available in the stabilization of expansive subgrade soil. Many researchers have made an attempt with the chemical stabilization technique, it has gained prominence due to its easy applicability and adaptability. Flyash is freely available waste product which has little cementing property can be used for altering the characteristics of expansive soil. The main objective of this work is to study the swelling properties of the expansive subgrade soil treated with chemicals like Magnesium Chloride (MgCl2, Aluminum Chloride (AlCl3 and also by adding flyash in varying percentages. The swelling properties of the collected expansive soil samples were determined based on the parameters like Free Swell Index, Swell Potential and Swell Pressure. The results obtained from the experimental study indicate that the measured Free Swell, Swell Potential and Swelling Pressure are reduced substantially with the increasing percent of chemicals and flyash and remain stable after reaching certain concentration. This paper discusses the results of the testing.

  1. Nanostructured conjugated polymers in chemical sensors: synthesis, properties and applications.

    Science.gov (United States)

    Correa, D S; Medeiros, E S; Oliveira, J E; Paterno, L G; Mattoso, Luiz C

    2014-09-01

    Conjugated polymers are organic materials endowed with a π-electron conjugation along the polymer backbone that present appealing electrical and optical properties for technological applications. By using conjugated polymeric materials in the nanoscale, such properties can be further enhanced. In addition, the use of nanostructured materials makes possible miniaturize devices at the micro/nano scale. The applications of conjugated nanostructured polymers include sensors, actuators, flexible displays, discrete electronic devices, and smart fabric, to name a few. In particular, the use of conjugated polymers in chemical and biological sensors is made feasible owning to their sensitivity to the physicochemical conditions of its surrounding environment, such as chemical composition, pH, dielectric constant, humidity or even temperature. Subtle changes in these conditions bring about variations on the electrical (resistivity and capacitance), optical (absorptivity, luminescence, etc.), and mechanical properties of the conjugated polymer, which can be precisely measured by different experimental methods and ultimately associated with a specific analyte and its concentration. The present review article highlights the main features of conjugated polymers that make them suitable for chemical sensors. An especial emphasis is given to nanostructured sensors systems, which present high sensitivity and selectivity, and find application in beverage and food quality control, pharmaceutical industries, medical diagnosis, environmental monitoring, and homeland security, and other applications as discussed throughout this review.

  2. Biochar physico-chemical properties as affected by environmental exposure.

    Science.gov (United States)

    Sorrenti, Giovambattista; Masiello, Caroline A; Dugan, Brandon; Toselli, Moreno

    2016-09-01

    To best use biochar as a sustainable soil management and carbon (C) sequestration technique, we must understand the effect of environmental exposure on its physical and chemical properties because they likely vary with time. These properties play an important role in biochar's environmental behavior and delivery of ecosystem services. We measured biochar before amendment and four years after amendment to a commercial nectarine orchard at rates of 5, 15 and 30tha(-1). We combined two pycnometry techniques to measure skeletal (ρs) and envelope (ρe) density and to estimate the total pore volume of biochar particles. We also examined imbibition, which can provide information about soil hydraulic conductivity. Finally, we investigated the chemical properties, surface, inner layers atomic composition and C1s bonding state of biochar fragments through X-ray photoelectron spectroscopy (XPS). Ageing increased biochar skeletal density and reduced the water imbibition rate within fragments as a consequence of partial pore clogging. However, porosity and the volume of water stored in particles remained unchanged. Exposure reduced biochar pH, EC, and total C, but enhanced total N, nitrate-N, and ammonium-N. X-ray photoelectron spectroscopy analyses showed an increase of O, Si, N, Na, Al, Ca, Mn, and Fe surface (0-5nm) atomic composition (at%) and a reduction of C and K in aged particles, confirming the interactions of biochar with soil inorganic and organic phases. Oxidation of aged biochar fragments occurred mainly in the particle surface, and progressively decreased down to 75nm. Biochar surface chemistry changes included the development of carbonyl and carboxylate functional groups, again mainly on the particle surface. However, changes were noticeable down to 75nm, while no significant changes were measured in the deepest layer, up to 110nm. Results show unequivocal shifts in biochar physical and chemical properties/characteristics over short (~years) timescales.

  3. Chemical properties of the heavier actinides and transactinides

    International Nuclear Information System (INIS)

    The chemical properties of each of the elements 99 (Es) through 105 are reviewed and their properties correlated with the electronic structure expected for 5f and 6d elements. A major feature of the heavier actinides, which differentiates them from the comparable lanthanides, is the increasing stability of the divalent oxidation state with increasing atomic number. The divalent oxidation state first becomes observable in the anhydrous halides of californium and increases in stability through the series to nobelium, where this valency becomes predominant in aqueous solution. In comparison with the analogous 4f electrons, the 5f electrons in the latter part of the series are more tightly bound. Thus, there is a lowering of the 5f energy levels with respect to the Fermi level as the atomic number increases. The metallic state of the heavier actinides has not been investigated except from the viewpoint of the relative volatility among members of the series. In aqueous solutions, ions of these elements behave as a normal trivalent actinides and lanthanides (except for nobelium). Their ionic radii decrease with increasing nuclear charge which is moderated because of increased screening of the outer 6p electrons by the 5f electrons. The actinide series of elements is completed with the element lawrencium (Lr) in which the electronic configuration is 5f147s27p. From Mendeleev's periodicity and Dirac-Fock calculations, the next group of elements is expected to be a d-transition series corresponding to the elements Hf through Hg. The chemical properties of elements 104 and 105 only have been studied and they indeed appear to show the properties expected of eka-Hf and eka-Ta. However, their nuclear lifetimes are so short and so few atoms can be produced that a rich variety of chemical information is probably unobtainable

  4. Chemical properties of the heavier actinides and transactinides

    Energy Technology Data Exchange (ETDEWEB)

    Hulet, E.K.

    1981-01-01

    The chemical properties of each of the elements 99 (Es) through 105 are reviewed and their properties correlated with the electronic structure expected for 5f and 6d elements. A major feature of the heavier actinides, which differentiates them from the comparable lanthanides, is the increasing stability of the divalent oxidation state with increasing atomic number. The divalent oxidation state first becomes observable in the anhydrous halides of californium and increases in stability through the series to nobelium, where this valency becomes predominant in aqueous solution. In comparison with the analogous 4f electrons, the 5f electrons in the latter part of the series are more tightly bound. Thus, there is a lowering of the 5f energy levels with respect to the Fermi level as the atomic number increases. The metallic state of the heavier actinides has not been investigated except from the viewpoint of the relative volatility among members of the series. In aqueous solutions, ions of these elements behave as a normal trivalent actinides and lanthanides (except for nobelium). Their ionic radii decrease with increasing nuclear charge which is moderated because of increased screening of the outer 6p electrons by the 5f electrons. The actinide series of elements is completed with the element lawrencium (Lr) in which the electronic configuration is 5f/sup 14/7s/sup 2/7p. From Mendeleev's periodicity and Dirac-Fock calculations, the next group of elements is expected to be a d-transition series corresponding to the elements Hf through Hg. The chemical properties of elements 104 and 105 only have been studied and they indeed appear to show the properties expected of eka-Hf and eka-Ta. However, their nuclear lifetimes are so short and so few atoms can be produced that a rich variety of chemical information is probably unobtainable.

  5. Biochar physico-chemical properties as affected by environmental exposure.

    Science.gov (United States)

    Sorrenti, Giovambattista; Masiello, Caroline A; Dugan, Brandon; Toselli, Moreno

    2016-09-01

    To best use biochar as a sustainable soil management and carbon (C) sequestration technique, we must understand the effect of environmental exposure on its physical and chemical properties because they likely vary with time. These properties play an important role in biochar's environmental behavior and delivery of ecosystem services. We measured biochar before amendment and four years after amendment to a commercial nectarine orchard at rates of 5, 15 and 30tha(-1). We combined two pycnometry techniques to measure skeletal (ρs) and envelope (ρe) density and to estimate the total pore volume of biochar particles. We also examined imbibition, which can provide information about soil hydraulic conductivity. Finally, we investigated the chemical properties, surface, inner layers atomic composition and C1s bonding state of biochar fragments through X-ray photoelectron spectroscopy (XPS). Ageing increased biochar skeletal density and reduced the water imbibition rate within fragments as a consequence of partial pore clogging. However, porosity and the volume of water stored in particles remained unchanged. Exposure reduced biochar pH, EC, and total C, but enhanced total N, nitrate-N, and ammonium-N. X-ray photoelectron spectroscopy analyses showed an increase of O, Si, N, Na, Al, Ca, Mn, and Fe surface (0-5nm) atomic composition (at%) and a reduction of C and K in aged particles, confirming the interactions of biochar with soil inorganic and organic phases. Oxidation of aged biochar fragments occurred mainly in the particle surface, and progressively decreased down to 75nm. Biochar surface chemistry changes included the development of carbonyl and carboxylate functional groups, again mainly on the particle surface. However, changes were noticeable down to 75nm, while no significant changes were measured in the deepest layer, up to 110nm. Results show unequivocal shifts in biochar physical and chemical properties/characteristics over short (~years) timescales. PMID

  6. BI-LAYER HYBRID BIOCOMPOSITES: CHEMICAL RESISTANT AND PHYSICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Mohammad Jawaid,

    2012-02-01

    Full Text Available Bi-layer hybrid biocomposites were fabricated by hand lay-up technique by reinforcing oil palm empty fruit bunch (EFB and jute fibre mats with epoxy matrix. Hybrid composites were prepared by varying the relative weight fraction of the two fibres. The physical (void content, density, dimensional stability, and chemical resistant properties of hybrid composites were evaluated. When the jute fibre loading increased in hybrid composites, physical and chemical resistant properties of hybrid composites were enhanced. Void content of hybrid composites decreased with an increase in jute fibre loading because jute fibres showed better fibre/matrix interface bonding, which leads to a reduction in voids. The density of hybrid composite increased as the quantity of jute fibre loading increased. The hybridization of the jute fibres with EFB composite improved the dimensional stability of the hybrid composites. The performance of hybrid composites towards chemical reagents improved with an increase in jute fibre loading as compared to the EFB composite. The combination of oil palm EFB/jute fibres with epoxy matrix produced hybrid biocomposites material that is competitive to synthetic composites.

  7. Maltodextrins from chemically modified starches. Selected physicochemical properties.

    Science.gov (United States)

    Pycia, Karolina; Juszczak, Lesław; Gałkowska, Dorota; Witczak, Mariusz; Jaworska, Grażyna

    2016-08-01

    The aim of this work was to evaluate the effect of chemical modification of starch (cross-linking and/or stabilisation) on selected rheological and functional properties of maltodextrins of dextrose equivalent of 6, 11 and 16. It was found that values of glass transition temperatures were decreasing with dextrose equivalent of maltodextrin. The highest values of glass transition temperature (TG) were determined for maltodextrin of DE 6-obtained from distarch phosphate and acetylated distarch phosphate. Increase in DE value of maltodextrin was also accompanied by decrease and increase in values of intrinsic viscosity and the critical concentration, respectively; however, there was no significant effect of kind of chemical modification of starch on the values of these parameters. Maltodextrin solutions at concentrations of from 10 to 70 % exhibited Newtonian flow behaviour. In the case of 50% solutions of maltodextrins of DE 6 the highest viscosity was produced by maltodextrin from native potato starch, while the lowest one by maltodextrin from acetylated starch. On the other hand, among the maltodextrin of DE 11 this one produced from acetylated starch showed the highest viscosity. All the maltodextrins exhibited surfactant properties in a water-air system, with the strongest effect observed for maltodextrins produced from double chemically modified starches and from acetylated starch. The surface activity was increasing with increasing of the DE value of maltodextrin. Moreover, values of surface tension were decreasing with increasing in maltodextrin concentration in the system. PMID:27112878

  8. Chemical scissors cut phosphorene and their novel electronic properties

    Science.gov (United States)

    Peng, Xihong; Wei, Qun

    2015-03-01

    Phosphorene, a recently fabricated two-dimensional puckered honeycomb structure of black phosphorus, showed promising properties for applications in nano-electronics. In this work, we report a chemical scissors effect on phosphorene, using first principles density-functional methods. It was found that chemical species, such as H, OH, F, and Cl, can act as scissors to cut phosphorene. Phosphorus nanochains and nanoribbons can be obtained using such chemical scissors. The scissors effect results from the strong bonding between the chemical species and phosphorus atoms. Other species such as O, S and Se fail to cut phosphorene due to their weak bonding with phosphorus. The electronic structures of the produced P-chains reveal that the hydrogenated P-chain is an insulator; however, the pristine P-chain is a one-dimensional Dirac material, in which the charge carriers are massless fermions travelling at an effective speed of light approximately 8x105 m/s. The obtained zigzag phosphorene nanoribbons show either metallic or semiconducting behaviors, depending on the treatment of the edge phosphorus atoms.

  9. Influence of fuel chemical properties on gas turbine combustors

    Science.gov (United States)

    Rosfjord, T. J.

    1984-01-01

    In an attempt to rigorously study the fuel chemical property influence, UTRC (United Technologies Research Center) (under contract to NASA Lewis Research Center) has conducted an experimental program using 25 test fuels. The burner was a 12.7 cm dia cylindrical device consisting of six sheet metal louvers. A single pressure atomizing injector and air swirler were centrally mounted with the conical dome. Fuel physical properties were de-emphasized by using fuel injectors which produced highly atomized, and hence rapidly vaporizing sprays. A substantial fuel spray characterization effort was conducted to allow selection of nozzles which assured that such sprays were achieved for all fuels. The fuels were specified to cover the following wide ranges of chemical properties: hydrogen, 9.1 to 15 (wt) pct; total aromatics, 0 to 100 (vol) pct; and naphthalene, 0 to 30 (vol) pct. They included standard fuel (e.g., Jet A, JP4), specialty products (e.g., decalin, xylene tower bottoms) and special fuel blends. Included in this latter group were six, 4-component blends prepared to achieve parametric variations in fuel hydrogen, total aromatics and naphthalene contents.

  10. The study of thermodynamic properties and transport properties of multicomponent systems with chemical reactions

    Directory of Open Access Journals (Sweden)

    Samujlov E.

    2013-04-01

    Full Text Available In case of system with chemical reaction the most important properties are heat conductivity and heat capacity. In this work we have considered the equation for estimate the component of these properties caused by chemical reaction and ionization processes. We have evaluated the contribution of this part in heat conductivity and heat capacity too. At the high temperatures contribution in heat conductivity from ionization begins to play an important role. We have created a model, which describe partial and full ionization of gases and gas mixtures. In addition, in this work we present the comparison of our result with experimental data and data from numerical simulation. We was used the data about transport properties of middle composition of Russian coals and the data of thermophysical properties of natural gas for comparison.

  11. Nuclear and chemical properties of the transactinide elements

    International Nuclear Information System (INIS)

    Transactinide elements, whose atomic number larger than 104 and classified as 6d-transition elements in the periodic table, have seldom been studied of the chemical nature in spite of much interest in the possible relativistic effects of these superheavy nuclides. This report briefly reviews recent topics in the advancement for the superheavy (Z > 104) nuclide synthesis by means of cold fusion with varying combinations of incident and target atoms using ion accelerators, for example, at GSI, Darmstadt, and at JINR, Dubna. It also reviews recent progress in their nuclear and chemical properties studied by a world-wide cooperative research group working at GSI, Mainz University, Bern University, PSI, Uppsala University, Dubna and LBL groups into which JAERI group has joined since 1998. Moreover, expectation is stated for the successful synthesis of superheavy elements on employment of radioactive beams consisting of neutron-excess nuclides. (Ohno, S.)

  12. Microwave transmission properties of chemical vapor deposition graphene

    Science.gov (United States)

    Wu, Yunqiu; Xu, Yuehang; Wang, Zegao; Xu, Cao; Tang, Zongxi; Chen, Yuanfu; Xu, Ruimin

    2012-07-01

    In this letter, the microwave transmission properties of graphene grown by the chemical vapor deposition are studied by using a multiple-layer coplanar-waveguide transmission-line based measurement method. Remarkable energy loss and phase shift have been observed in graphene from the measured scattering parameters through vector network analyzer. The effective permittivity is deduced by partial-capacitance technique, and the complex permittivity of graphene are extracted in the frequency range of 500 MHz to 6 GHz. Different from conventional dielectric material, the permittivity of graphene shows frequency-dependent below 4 GHz and has an magnitude larger than 104 for both real and imaginary parts.

  13. Predicting Radiocaesium Sorption with Soil Chemical Properties in Japanese Soils

    International Nuclear Information System (INIS)

    The soil-to-plant transfer mechanism of radiocaesium (137Cs) in the Fukushima accident affected area is not fully understood. The sorption of 137Cs in soils holds a key to evaluating the variation of transfer of 137Cs to plant among different soil types. This study aims to investigate how differences in 137Cs adsorption in different soils can be explained by soil chemical and mineralogical properties. The Radiocaesium Interception Potential (RIP), a parameter for quantifying immediate 137Cs adsorption, and the soil texture were determined for 52 surface soils covering a wide range of texture classes collected from the area contaminated by the Fukushima accident. These soils include Andosols, Fluvisols, Gleysols, and Cambisols. In addition, we are currently performing analyses for other soil chemical properties (i.e. exchangeable cation, CEC, pH, organic matter content, etc) and for the properties affecting 137Cs sorption in soils (i.e. Frayed Edge Site capacity, K+ and NH4+ selectivity, effect of wet-dry cycles, etc). The average RIP varied from 80 to 4300 mmol kg-1 between soils. Contrary to what was found for temperate region soils by Absalom et al., the RIP (log(RIP)) and soil clay content were not significantly correlated (R2= 0.066). These initial results seem to indicate that the 137Cs sorption is affected by the clay mineralogy in soils. We postulate that by considering also the differences in clay K content, the relationship will improve since the frayed edges are formed at high K content in the clay. This knowledge could improve the prediction of RIP for different Japanese soil groups. Further analysis of the data will explore the relationship between RIP and other soil chemical properties. In our study, we will take specific note of Andosols (range of average RIP from 80 to 2400 mmol kg-1), typical soils in Japan originated from volcanic ash. It is expected that soil properties ruling the 137Cs sorption for Japanese Andosols will differ compared to other

  14. Predicting Radiocaesium Sorption with Soil Chemical Properties in Japanese Soils

    Energy Technology Data Exchange (ETDEWEB)

    Uematsu, Shinichiro [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven (Belgium); Van Hees, May; Wannijn, Jean; Sweeck, Lieve; Vandenhove, Hildegarde [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Smolders, Erik [Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven (Belgium)

    2014-07-01

    The soil-to-plant transfer mechanism of radiocaesium ({sup 137}Cs) in the Fukushima accident affected area is not fully understood. The sorption of {sup 137}Cs in soils holds a key to evaluating the variation of transfer of {sup 137}Cs to plant among different soil types. This study aims to investigate how differences in {sup 137}Cs adsorption in different soils can be explained by soil chemical and mineralogical properties. The Radiocaesium Interception Potential (RIP), a parameter for quantifying immediate {sup 137}Cs adsorption, and the soil texture were determined for 52 surface soils covering a wide range of texture classes collected from the area contaminated by the Fukushima accident. These soils include Andosols, Fluvisols, Gleysols, and Cambisols. In addition, we are currently performing analyses for other soil chemical properties (i.e. exchangeable cation, CEC, pH, organic matter content, etc) and for the properties affecting {sup 137}Cs sorption in soils (i.e. Frayed Edge Site capacity, K{sup +} and NH{sub 4}{sup +} selectivity, effect of wet-dry cycles, etc). The average RIP varied from 80 to 4300 mmol kg{sup -1} between soils. Contrary to what was found for temperate region soils by Absalom et al., the RIP (log(RIP)) and soil clay content were not significantly correlated (R2= 0.066). These initial results seem to indicate that the {sup 137}Cs sorption is affected by the clay mineralogy in soils. We postulate that by considering also the differences in clay K content, the relationship will improve since the frayed edges are formed at high K content in the clay. This knowledge could improve the prediction of RIP for different Japanese soil groups. Further analysis of the data will explore the relationship between RIP and other soil chemical properties. In our study, we will take specific note of Andosols (range of average RIP from 80 to 2400 mmol kg{sup -1}), typical soils in Japan originated from volcanic ash. It is expected that soil properties ruling

  15. Rheological properties of kaolin and chemically simulated waste

    International Nuclear Information System (INIS)

    The Savannah River Laboratory is conducting tests to determine the best operating conditions of pumps used to transfer insoluble radioactive sludges from old to new waste tanks. Because it is not feasible to conduct these tests with real or chemically simulated sludges, kaolin clay is being used as a stand-in for the solid waste. The rheology tests described herein were conducted to determine whether the properties of kaolin were sufficiently similar to those of real sludge to permit meaningful pump tests. The rheology study showed that kaolin can be substituted for real waste to accurately determine pump performance. Once adequately sheared, kaolin properties were found to remain constant. Test results determined that kaolin should not be allowed to settle more than two weeks between pump tests. Water or supernate from the waste tanks can be used to dilute sludge on an equal volume basis because they identically affect the rheological properties of sludge. It was further found that the fluid properties of kaolin and waste are insensitive to temperature

  16. The physical and chemical properties of ultrathin oxide films.

    Science.gov (United States)

    Street, S C; Xu, C; Goodman, D W

    1997-01-01

    Thin oxide films (from one to tens of monolayers) of SiO2, MgO, NiO, Al2O3, FexOy, and TiO2 supported on refractory metal substrates have been prepared by depositing the oxide metal precursor in a background of oxygen (ca 1 x 10(-5) Torr). The thinness of these oxide samples facilitates investigation by an array of surface techniques, many of which are precluded when applied to the corresponding bulk oxide. Layered and mixed binary oxides have been prepared by sequential synthesis of dissimilar oxide layers or co-deposition of two different oxides. Recent work has shown that the underlying oxide substrate can markedly influence the electronic and chemical properties of the overlayer oxide. The structural, electronic, and chemical properties of these ultrathin oxide films have been probed using Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), electron energy loss spectroscopy (ELS), ion-scattering spectroscopy (ISS), high-resolution electron energy loss spectroscopy (HREELS), infrared reflectance absorption spectroscopy (IRAS), temperature-programmed desorption (TPD), scanning tunneling microscopy (STM), and scanning tunneling spectroscopy (STS).

  17. Theoretical investigation of chemical and physical properties of gaseous fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, Fredrik

    1999-12-01

    This thesis is discussing the chemical and physical properties of different gaseous fuels. A mapping of about seventy gaseous fuels resulted in eleven type gases, these gases have mainly five components (inerts, H{sub 2}, CO, CH{sub 4} and higher order of hydrocarbons) of different quantities. Calculations of heating value and Wobbe number have been done. Dew point temperatures have been estimated by using three different programs. Flammability limits, laminar flame speed and auto ignition temperatures have been calculated by using a kinetic and chemical program developed by Mauss. Flammability limits have been compared with Le Chatelier's law and measurements. Problems related to combustion such as flash back, lift off and instability are closely connected with flame speed and flow patterns. These problems are discussed in terms of laminar flame speed and Reynolds' number. The main results of this study were: Auto ignition temperature for gas mixtures behavior is very complex and unpredictable. In general small quantities of hydrogen decrease the temperature of auto ignition. The calculations of flammability limits by the kinetic and chemical software showed good agreement to measurements. Low Btu gases requires large flow area in order to avoid large pressure drop.

  18. Chemical properties of two-year-old deciduous species

    Energy Technology Data Exchange (ETDEWEB)

    Chow, P.; Rolfe, G.L.; Lee, C.S.; White, T.A.

    1983-01-01

    Contents of ash, hot-water extractives, 1% sodium hydroxide extractives, alcohol-benzene extractive, lignin, holocellulose, alpha-cellulose, and pentosan were determined on two-year-old, short-rotation trees of autumn olive, black alder, black locust, eastern cottonwood, royal paulownia, silver maple, and sycamore. These plantations were established in 1978 on marginal agricultural land that was not suitable for food production in Illinois. Six comparable species of commercial lumber were also analyzed. Test results indicated that all chemical properties did vary with species, above-ground tree portions, and ages of species. The two-year-old juvenile trees had higher average extractives, holocellulose, pentosan, and ash content than did the lumber of matured wood. Black locust possessed the highest values of holocellulose and alpha-cellulose, while the eastern cottonwood had the highest extractive contents. Silver maple had the highest lignin content. Both bark and branches which consisted of about 32% of the mass weight of young trees, had a higher average lignin, extractive and ash content than those of the stemwood. Based on chemical composition, these seven juvenile deciduous species could serve as a raw material for the paper and chemical industries, as well as for energy. 19 references, 8 figures, 6 tables.

  19. Chemical composition and surface charge properties of montmorillonite

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-wen; HU Min; HU Yue-hua

    2008-01-01

    The effects of the cell parameter and chemical composition on the surface charge properties of five kinds of different colour montmorillonites were studied. The results indicate that the surface isoelectric point(IEP) of the montmorillonite shows positive correlation with the mass fractions of Fe2O3 and K20, but it has little relation to the mass fractions of other chemical compositions. At around pH=6.8, the surface zeta potential of the montmorillonite shows the negative relationship with the mass fractions of Fe2O3 and MgO, but it does not linearly correlate to the mass fractions of other chemical compositions. Cell parameter(b0) of the montmofillonite expresses negative linear relationship with mass fractions of K2O and Na2O, so does c0sinβ with mass fractions of SiO2 and Fe2O3. And there is no specific relationship between bo and IEP of different montmori Uonites, but there is positive correlation between c0sinβ and IEP of different montmorillonite samples.

  20. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  1. EFFECT OF ALTERNATIVE MULTINUTRIENT SOURCES ON SOIL CHEMICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Vanessa Martins

    2015-02-01

    Full Text Available The current high price of potassium chloride and the dependence of Brazil on imported materials to supply the domestic demand call for studies evaluating the efficiency of alternative sources of nutrients. The aim of this work was to evaluate the effect of silicate rock powder and a manganese mining by-product, and secondary materials originated from these two materials, on soil chemical properties and on brachiaria production. This greenhouse experiment was conducted in pots with 5 kg of soil (Latossolo Vermelho-Amarelo distrófico - Oxisol. The alternative nutrient sources were: verdete, verdete treated with NH4OH, phonolite, ultramafic rock, mining waste and the proportion of 75 % of these K fertilizers and 25 % lime. Mixtures containing 25 % of lime were heated at 800 ºC for 1 h. These sources were applied at rates of 0, 150, 300, 450 and 600 kg ha-1 K2O, and incubated for 45 days. The mixtures of heated silicate rocks with lime promoted higher increases in soil pH in decreasing order: ultramafic rock>verdete>phonolite>mining waste. Applying the mining waste-lime mixture increased soil exchangeable K, and available P when ultramafic rock was incorporated. When ultramafic rock was applied, the release of Ca2+ increased significantly. Mining subproduct released the highest amount of Zn2+ and Mn2+ to the soil. The application of alternative sources of K, with variable chemical composition, altered the nutrient availability and soil chemical properties, improving mainly plant development and K plant uptake, and are important nutrient sources.

  2. Effects of scalp dermatitis on chemical property of hair keratin

    Science.gov (United States)

    Kim, Kyung Sook; Shin, Min Kyung; Park, Hun-Kuk

    2013-05-01

    The effects of scalp dermatitis (seborrheic dermatitis (SD), psoriasis, and atopic dermatitis (AD)) on chemical properties of hair keratin were investigated by Fourier transform infrared (FT-IR) spectroscopy. Hairs were collected from lesional regions affected by SD, psoriasis, and AD and non-lesional regions separately. The hairs with SD were taken from patients with ages of 16-80 years. The ages of patients with psoriasis ranged from 8 to 67 years, and all patients exhibited moderate disease. Hairs with AD were taken from the patients with ages of 24-45 years and the average SCORing atopic dermatitis (SCORAD) was 48.75. Hairs from 20 normal adults were collected as a control. The FT-IR absorbance bands were analyzed by the Gaussian model to obtain the center frequency, half width, height, and area of each band. The height and area of all bands in the spectra were normalized to the amide I centered at 1652 cm-1 to quantitatively analyze the chemical composition of keratin. The spectra of hair with scalp dermatitis were different with that of control, the amide A components centered at 3278 cm-1 were smaller than those of the control. The psoriasis hair showed a large difference in the IR absorbance band between lesional and non-lesional hairs indicating good agreement with the morphological changes. The hairs with diseases did not show differences in the content of cystine, which was centered at 1054 cm-1, from the control. The chemical properties of keratin were not significantly different between the hairs affected by SD, psoriasis, and AD. However, the changes induced by scalp dermatitis were different with weathering. Therefore, FT-IR analysis could be used to screen differences between the physiological and pathological conditions of scalp hair.

  3. Chemical and physical properties of opencast lignite minesoils

    Energy Technology Data Exchange (ETDEWEB)

    Varela, C.; Vazquez, C.; Gonzalez-Sangregorio, M.V.; Leiros, M.C.; Gil-Sotres, F. (Facultad de Farmacia de Santiago de Compostela, Santiago de Compostela (Spain). Dept. de Edafologia y Quimica Agricola)

    1993-09-01

    The evolution of chemical and physical properties in a series of mine soils aged between 0 and 5 years, developed from spoil materials of the Meirama opencast lignite mine in Galicia (NW Spain), was studied. The soils are recovered without use of topsoil and are subject to identical management. In the surface horizon (0-7 cm), total C and N, CEC, and pyrophosphate-extracted Al[sub 2]O[sub 3] and Fe[sub 2]O[sub 3] increased with soil age. Oxalic-oxalate-extracted Al[sub 2]O[sub 3] and Fe[sub 2]O[sub 3] on the other hand, increased with soil age in all the horizons studied. Rapid recovery in terms of physical properties was also observed: bulk density dropped, while total porosity, percentage of macropores, and hydraulic conductivity increased, and aggregates showed greater stability on immersion in water. The results indicate that mineral weathering and organometallic complexation are the dominant processes at these early stages of edaphogenesis and that properties associated with gas exchange showed more rapid development than those associated with water movement. In spite of the above rapid modifications, the characteristics of the oldest soils in the series were still very different from those of native Galician soils.

  4. CONCRETE PROPERTIES IMPROVEMENT OF SLAB TRACKS USING CHEMICAL ADDITIVES

    Directory of Open Access Journals (Sweden)

    V. V. Pristinskaya

    2015-11-01

    Full Text Available Purpose. On the Railways of Ukraine a very large number of slab tracks are operated with cracks. Many scientific works of previous years are dedicated to improving the design of slab tracks. The main causes of defects are: poor exploitation of the track; insufficient physic-mechanical characteristics of concrete; poor quality of initial materials. It is therefore necessary to develop an optimum concrete mix for the manufacture of these concrete products. Methodology. To assess the impact of individual factors and effects of their interactions on properties of concrete mix and concrete method of experimental and statistical modeling was used. At this, methodological fundamentals of mathematical experiment planning in concrete technology and modern methods of optimization of composite materials were taking into account. Based on the obtained data during the planned experiment conducting, including15 studies and using the computer program MathCad, were obtained the regression equations, which describe the relevant physical and mechanical properties of concrete. On the basis of the equations with the help of computer program MATLAB R2012b the graphs were drawn, illustrating the dependences of system response from the changes of two factors at a fixed value of the third factor. Findings. Firstly was the analysis of cracks that occur in the process of operation in the constructions of slab tracks. Further reasons of possible occurrence of these cracks were presented. In the process of the conducted research the author has concluded that for rational concrete mix development it is necessary to conduct the planned experiment with the use of quality materials. It was established that to increase the strength, chemical additives should be added in to concrete mix, it will let reduce cement amount. Originality. Experiments proved the usage of modern chemical additives in order to improve the properties of concrete. Models were developed, reflecting

  5. Field emission properties of chemical vapor deposited individual graphene

    Energy Technology Data Exchange (ETDEWEB)

    Zamri Yusop, Mohd [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan); Department of Materials, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Kalita, Golap, E-mail: kalita.golap@nitech.ac.jp [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan); Center for Fostering Young and Innovative Researchers, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan); Yaakob, Yazid; Takahashi, Chisato; Tanemura, Masaki [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan)

    2014-03-03

    Here, we report field emission (FE) properties of a chemical vapor deposited individual graphene investigated by in-situ transmission electron microscopy. Free-standing bilayer graphene is mounted on a cathode microprobe and FE processes are investigated varying the vacuum gap of cathode and anode. The threshold field for 10 nA current were found to be 515, 610, and 870 V/μm for vacuum gap of 400, 300, and 200 nm, respectively. It is observed that the structural stability of a high quality bilayer graphene is considerably stable during emission process. By contacting the nanoprobe with graphene and applying a bias voltage, structural deformation and buckling are observed with significant rise in temperature owing to Joule heating effect. The finding can be significant for practical application of graphene related materials in emitter based devices as well as understanding the contact resistance influence and heating effect.

  6. Chemical and electrical properties of LSM cathodes prepared by mechanosynthesis

    Science.gov (United States)

    Moriche, R.; Marrero-López, D.; Gotor, F. J.; Sayagués, M. J.

    2014-04-01

    Mechanosynthesis of La1-xSrxMnO3 (x = 0, 0.25, 0.5, 0.75 and 1) was carried out at room temperature from stoichiometric mixtures of La2O3, Mn2O3 and SrO, obtaining monophasic powders with the perovskite structure. Physical properties of these materials and their chemical compatibility with the electrolyte yttria stabilized zirconia (YSZ), which depend strongly on the La/Sr ratio, were evaluated to corroborate availability to be implemented as cathode material in solid oxide fuel cells (SOFCs). Electrical conductivity values in air ranged between 100 and 400 S cm-1 in the temperature range of 25-850 °C. Samples presented low reactivity with YSZ in the working temperature range (600-1000 °C) maintaining the grain size small enough to preserve the catalytic activity for oxygen reduction.

  7. Influence of Biomass Chemical Properties on Torrefaction Characteristics

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti; Hansen, Brian Brun; Jensen, Peter Arendt;

    2013-01-01

    Different biomass types may differ with respect to torrefaction characteristics, and an improved understanding and ability to predict the torrefaction performance is, therefore, desired. In this study, the influence of the chemical properties (lignocellulose composition and alkali content......) on the torrefaction behavior with respect to mass loss and grindability is investigated by simultaneous thermal analysis (STA) and by using a combined torrefaction and grinding reactor. The torrefaction behavior of six raw biomass samples and selected pretreated samples (washed and impregnated with KCl and K2CO3) has...... content increased from 0 to 0.2 wt %. However, the higher lignin content in bark causes a higher solid yield than what would be expected from the alkali content, illustrating that both potassium content and lignocellulose composition affect the solid yield obtained by torrefaction. The grindability...

  8. Quantum-chemical approach to cohesive properties of metallic beryllium

    International Nuclear Information System (INIS)

    Calculations based upon the incremental approach, i.e. an expansion of the correlation energy in terms of one-body, two-body, and higher-order contributions from localized orbital groups, have been performed for metallic beryllium. We apply an embedding scheme which has been successfully applied recently to ground-state properties of magnesium and group 12 elements. This scheme forces localization in metallic-like model systems and allows for a gradual delocalization within the incremental approach. Quantum-chemical methods of the coupled-cluster and multi-reference configuration interaction type are used for evaluating individual increments. Results are given for the cohesive energy and lattice constants of beryllium, and it is shown that further development of the approach is needed for this difficult case

  9. Physical properties and chemical composition of Segamat Kaolin, Johor, Malaysia

    International Nuclear Information System (INIS)

    Kaolin is a source of secondary mineral as a product of a weathering process of primary minerals. Its main component is fine grain kaolinite (< 2 μm) and it also contains other elements such as aluminium and iron phyllosilicate as the pigment. Aluminium rich kaolin is light in colour with high plasticity and is normally used in the ceramic, plastic, paint, paper, pesticide, pharmacology and cosmetic industries. The physical and chemical characteristics of kaolins are important for its potential application. In this study, about 25 kaolin samples were hand-augered from depths of 1-2 m at Buloh Kasap Segamat, Johor, Malaysia. Chemical analysis carried out included determination of oxides and types of minerals by X-ray diffraction and X-ray fluorescence. Shrinkage rate, rupture modulus and water absorption rate tests were carried out in the physical properties analysis. Plastic and liquid limits of the kaolin were also measured for plastic index. The Segamat kaolin was light in colour due to its high silicate composition. The highest mineral content in the kaolin was kaolinite and quartz occurred as impurities. The low shrinkage rate showed that the kaolin was dense with little voids, hence very suitable for use in the ceramic industry. This kaolin has low water absorption, plasticity and durable according to the rupture modulus test. (author)

  10. Effect of surface properties of fibres on some paper properties of mechanical and chemical pulp

    OpenAIRE

    Koljonen, Krista

    2004-01-01

    The overall goal of the thesis was to find correlations between the surface precipitates of pulps and selected strength properties of paper sheets. Special attention was paid to the surface lignin and extractives of fibres. The main surface-characterising techniques employed were electron spectroscopy for chemical analysis (ESCA), atomic force microscopy (AFM) and the polyelectrolyte titration method. In addition, a Wilhelmy balance for single fibres, time-of-flight secondary ion mass spectro...

  11. Robinia pseudoacacia leaves improve soil physical and chemical properties

    Institute of Scientific and Technical Information of China (English)

    Babar; KHAN; Abdukadir; Ablimit; Rashed; MAHMOOD; Muhammad; QASIM

    2010-01-01

    The role of the leaves of Robinia pseudoacacia L., which is widely distributed in the arid lands, on improving soil physical and chemical properties was analyzed at various incubation periods. The incubated soils added with 0, 25, 50 and 75 g Robinia pseudoacacia leaves were tested after consecutive incubation intervals of 6, 8 and 10 months and the different soil parameters were measured. The results showed the increases in organic matter (OM), extractable K, cation exchange capacity (CEC), aggregate stability and water holding capacity, but the decreases in pH value and bulk density after 6 months’ incubation. The gradual decrease in change rates of soil properties indicated less microbial population and organic residual mineralization under acidic conditions, which were resulted from fast decomposition of leaves after the first 6 months incubation. The increases in soil organic matter content, extractable K, CEC, aggregate stability and water holding capacity and the decreases in soil pH and bulk density provide favorable conditions for crop’s growth.

  12. Robinia pseudoacacia leaves improve soil physical and chemical properties

    Institute of Scientific and Technical Information of China (English)

    Babar KHAN; Abdukadir Ablimit; Rashed MAHMOOD; Muhammad QASIM

    2010-01-01

    The role of the leaves of Robinia pseudoacacia L.,which is widely distributed in the arid lands,on improving soil physical and chemical properties was analyzed at various incubation periods.The incubated soils added with 0,25,50 and 75 g Robinia pseudoacacia leaves were tested after consecutive incubation intervals of 6,8 and 10 months and the different soil parameters were measured.The results showed the increases in organic matter (OM),extractable K,cation exchange capacity (CEC),aggregate stability and water holding capacity,but the decreases in pH value and bulk density after 6 months' incubation.The gradual decrease in change rates of soil properties indicated less microbial population and organic residual mineralization under acidic conditions,which were resulted from fast decomposition of leaves after the first 6 months incubation.The increases in soil organic matter content,extractable K,CEC,aggregate stability and water holding capacity and the decreases in soil pH and bulk density provide favorable conditions for crop's growth.

  13. Chemical and nuclear properties of Rutherfordium (Element 104)

    Energy Technology Data Exchange (ETDEWEB)

    Kacher, C.D.

    1995-10-30

    The chemical-properties of rutherfordium (Rf) and its group 4 homologs were studied by sorption on glass support surfaces coated with cobalt(II)ferrocyanide and by solvent extraction with tributylphosphate (TBP) and triisooctylamine (TIOA). The surface studies showed that the hydrolysis trend in the group 4 elements and the pseudogroup 4 element, lb, decreases in the order Rf>Zr{approx}Hf>Th. This trend was attributed to relativistic effects which predicted that Rf would be more prone to having a coordination number of 6 than 8 in most aqueous solutions due to a destabilization of the 6d{sub 5/2} shell and a stabilization of the 7p{sub l/2} shell. This hydrolysis trend was confirmed in the TBP/HBr solvent extraction studies which showed that the extraction trend decreased in the order Zr>Hf>Rf?Ti for HBr, showing that Rf and Ti did not extract as well because they hydrolyzed more easily than Zr and Hf. The TIOA/HF solvent extraction studies showed that the extraction trend for the group 4 elements decreased in the order Ti>Zr{approx}Hf>Rf, in inverse order from the trend of ionic radii Rf>Zr{approx}Hf>Ti. An attempt was made to produce {sup 263}Rf (a) via the {sup 248}Cm({sup 22}Ne, {alpha}3n) reaction employing thenoyltrifluoroacetone (TTA) solvent extraction chemistry and (b) via the {sup 249}Bk({sup 18}O,4n) reaction employing the Automated Rapid Chemistry Apparatus (ARCA). In the TTA studies, 16 fissions were observed but were all attributed to {sup 256}Fm. No alpha events were observed in the Rf chemical fraction. A 0.2 nb upper limit production cross section for the {sup 248}Cm({sup 22}Ne, {alpha}3n){sup 263}Rf reaction was calculated assuming the 500-sec half-life reported previously by Czerwinski et al. [CZE92A].

  14. The impact of chemical evolution on the observable properties of stellar populations

    CERN Document Server

    Tosi, M P

    2000-01-01

    The major effects of the chemical evolution of galaxies on the characteristics of their stellar populations are reviewed. A few examples of how the observed stellar properties derived from colour--magnitude diagrams can constrain chemical evolution models are given.

  15. Physical and chemical and physico technical properties of stalks of thecotton

    International Nuclear Information System (INIS)

    In this article authors investigated physical and chemical and physicotechnical properties of stalks of the cotton. These investigations letdetermine physical and chemical bases of structure forming of materials,articles and constructions with its application

  16. Quantitative structure-property relationships for chemical functional use and weight fractions in consumer articles

    Science.gov (United States)

    Chemical functional use -- the functional role a chemical plays in processes or products -- may be a useful heuristic for predicting human exposure potential in that it comprises information about the compound's likely physical properties and the product formulations or articles ...

  17. Physical, Chemical and Mineral Properties of the Polonnaruwa Stones

    Science.gov (United States)

    Wallis, Jamie; Wickramasinghe, N. C.; Wallis, Daryl H.; Miyake, Nori; Wallis, M. K.; Hoover, Richard B.; Samaranayake, Anil; Wickramarathne, Keerthi; Oldroyd, Anthony

    We report on the physical, chemical and mineral properties of a series of stone fragments recovered from the North Central Province of Sri Lanka following a witnessed fireball event on 29 December 2012. The stones exhibit highly porous poikilitic textures comprising of isotropic silica-rich/plagioclase-like hosts. Inclusions range in size and shape from mm-sized to smaller subangular grains frequently more fractured than the surrounding host and include ilmenite, olivine (fayalitic), quartz and accessory zircon. Bulk mineral compositions include accessory cristobalite, hercynite, anorthite, wuestite, albite, anorthoclase and the high pressure olivine polymorph wadsleyite, suggesting previous endurance of a shock pressure of ~20GPa. Further evidence of shock is confirmed by theconversion of all plagioclase to maskelynite. Here the infrared absorption spectra in the region 580 cm-1 to 380 cm-1 due to the Si-O-Si or Si-O-Al absorption band shows a partial shift in the peak at 380 cm-1 towards 480 cm-1 indicating an intermediate position between crystalline and amorphous phase. Host matrix chemical compositions vary between samples, but all are rich in SiO2. Silica-rich melts display a heterogeneous K-enrichment comparable to that reported in a range of nonterrestrial material from rare iron meteorites to LL chondritic breccias and Lunar granites. Bulk chemical compositions of plagioclase-like samples are comparable to reported data e.g. Miller Ranger 05035 (Lunar), while Si-rich samples accord well with mafic and felsic glasses reported in NWA 1664 (Howardite)as well asdata for fusion crust present in a variety of meteoritic samples.Triple oxygen isotope results show Δ17O = .0.335 with δ18O (‰ rel. SMOW) values of 17.816 ± 0.100 and compare well with those of known CI chondrites and are within the range of CI-like (Meta-C) chondrites. Rare earth elemental abundances show a profound Europium anomaly of between 0.7 and 0.9 ppm while CI normalized REE patterns

  18. Hygroscopic, Morphological, and Chemical Properties of Agricultural Aerosols

    Science.gov (United States)

    Hiranuma, N.; Brooks, S. D.; Cheek, L.; Thornton, D. C.; Auvermann, B. W.; Littleton, R.

    2007-12-01

    Agricultural fugitive dust is a significant source of localized air pollution in the semi-arid southern Great Plains. In the Texas Panhandle, daily episodes of ground-level fugitive dust emissions from the cattle feedlots are routinely observed in conjunction with increased cattle activity in the late afternoons and early evenings. We conducted a field study to characterize size-selected agricultural aerosols with respect to hygroscopic, morphological, and chemical properties and to attempt to identify any correlations between these properties. To explore the hygroscopic nature of agricultural particles, we have collected size-resolved aerosol samples using a cascade impactor system at a cattle feedlot in the Texas Panhandle and have used the Environmental Scanning Electron Microscope (ESEM) to determine the water uptake by individual particles in those samples as a function of relative humidity. To characterize the size distribution of agricultural aerosols as a function of time, A GRIMM aerosol spectrometer and Sequential Mobility Particle Sizer and Counter (SMPS) measurements were simultaneously performed in an overall size range of 11 nm to 20 µm diameters at a cattle feedlot. Complementary determination of the elemental composition of individual particles was performed using Energy Dispersive X-ray Spectroscopy (EDS). In addition to the EDS analysis, an ammonia scrubber was used to collect ammonia and ammonium in the gas and particulate phases, respectively. The concentration of these species was quantified offline via UV spectrophotometry at 640 nanometers. The results of this study will provide important particulate emission data from a feedyard, needed to improve our understanding of the role of agricultural particulates in local and regional air quality.

  19. Chemical properties and antioxidant and antimicrobial activities of Slovenian propolis.

    Science.gov (United States)

    Mavri, Ana; Abramovič, Helena; Polak, Tomaž; Bertoncelj, Jasna; Jamnik, Polona; Smole Možina, Sonja; Jeršek, Barbara

    2012-08-01

    The chemical composition as well as the antioxidant and antimicrobial activities of two EtOH extracts of propolis (PEEs) from Slovenia were determined. EtOH was used as extracting solvent at 70 and 96%, providing the extracts PEE70 and PEE96, respectively. The extraction with 70% EtOH was more efficient than that with 96% EtOH, as the PEE70 was richer in total phenolic compounds than the PEE96. The Slovenian propolis was characterized by different phenolic acids and flavonoids. The PEE96 was slightly richer in three specific compounds, i.e., caffeic acid, ferulic acid, and luteolin, while all other substances detected showed higher contents in the PEE70. The PEE70 showed a stronger reducing power and ability to scavenge free radicals and metal ions than the PEE96. Both PEEs were in the main more effective against Gram-positive bacteria than against fungi and Gram-negative bacteria like Salmonella and Escherichia coli, with the exception of Campylobacter. The PEE96 decreased the intracellular oxidation in Saccharomyces cerevisiae in a dose-dependent manner. The antimicrobial activities and antioxidant properties were related to the total phenolic contents. The two PEEs have the potential for use as natural antimicrobial and antioxidant additives in foods.

  20. Dynamical and chemical properties of the "starless" core L1014

    CERN Document Server

    Crapsi, A; De Vries, C H; Huard, T L; Jørgensen, J K; Kauffmann, J; Lee, C W; Lee, J E; Myers, P C; Ridge, N A; Shirley, Y L; Young, C H

    2005-01-01

    Spitzer Space Telescope observations of a point-like source, L1014-IRS, close to the dust peak of the low-mass dense core L1014 have questioned its starless nature. The presence of an object with colors expected for an embedded protostar makes L1014-IRS the lowest luminosity isolated protostar known, and an ideal target with which to test star formation theories at the low mass end. In order to study its molecular content and to search for the presence of a molecular outflow, we mapped L1014 in at least one transition of 12CO, N2H+, HCO+, CS and of their isotopologues 13CO, C18O, C17O, N2D+ and H13CO+, using the FCRAO, the IRAM 30 meter and the CSO. The data show physical and chemical properties in L1014 typical of the less evolved starless cores: i.e. H2 central density of a few 10^5 molecules cm^-3, estimated mass of ~2M_sun, CO integrated depletion factor less than 10, N(N2H+)~6*10^12 cm^-2, N(N2D+)/N(N2H+) equal to 10% and relatively broad N2H+(1--0) lines (0.35 km/s). Infall signatures and significant ve...

  1. Characterisation of gaharu hydrosol: Physical, chemical and microbiological properties

    International Nuclear Information System (INIS)

    Gaharu hydrosol is produced during the hydro distillation of resinous wood part of Aquilaria sp. This aromatic water is being considered as a by-product in the industry. There is interest to turn this aromatic by-product into aroma therapy products. The present study is carried out in order to understand the properties of gaharu hydrosol, physically, chemically and microbiologically. Gaharu hydrosol from two different extraction facilities for example at Kedaik Agar wood Sdn. Bhd. and Malaysian Nuclear Agency were characterised in this study. All the gaharu hydrosol samples displayed acidic nature, with pH in the range of 3.62 - 4.53. Four antioxidant assays were carried out to ascertain the antioxidant capabilities of two gaharu hydrosol samples through the total phenolic content assay, ABTS+ radical scavenging activity, DPPH· radical scavenging activity and ferric reducing activity (FRAP). The results revealed that the samples exhibited lower antioxidant capabilities as compared to the positive control. For microbial population study, fungi was not present in the samples as there was no growth observed on the Plate Sabouraud Dextrose Agar (SDA) using membrane filtration technique. The antibacterial activity of the gaharu hydrosol against Staphylococcus aureus and Pseudomonas aeruginosa was determined using agar dilution method and disk diffusion method. The results showed that the gaharu hydrosol did not inhibit the growth of both the bacteria. The results obtained from this study will be further evaluated for the development of new products using this aromatic gaharu by-product. (author)

  2. Experimental study on the physical and chemical properties of the deep hard brittle shale

    OpenAIRE

    Jian Xiong; Xiangjun Liu; Lixi Liang; Yi Ding; Meng Lei

    2016-01-01

    In the hard brittle shale formation, rock composition, physical and chemical properties, mechanics property before and after interacting with fluid have direct relation with borehole problems, such as borehole wall collapse, mud loss, hole shrinkage. To achieve hard brittle shale micro-structure, physical–chemical properties and mechanics property, energy-dispersive X-ray diffraction (XRD), cation exchange capacity experiment and hardness test are conducted. The result of laboratory experimen...

  3. Study of chemical and physical properties of irradiated Guar Gum

    International Nuclear Information System (INIS)

    This study was carried out to evaluate the effect of different gamma radiation doses to decontamination of micro-organisms present in Guar Gum powder. As well as to study the effect of radiation on the chemical and physical properties of the carbohydrate components of the Gum's material. Two types of samples were used in this study (powder and liquid). All samples were collected from commercially available Guar Gum (G G), which were obtained from the company (Sudanese Guar Gum ltd). Samples putted in polyethylene tightly closed container, then irradiated by applying different doses (2.5, 5, 7.5, 10, 20,30,40,and 50 kGy) from Co-60 source at room temperature in air. And take zero kGy as control. Irradiated powder samples of (2.5, 5, 7.5, 10 kGy) were investigated for contamination by using growth media agar and the result showed that 2.5 kGy is appropriate dose to remove the contamination of the samples. And then analyzed using fourier transform infrared (FTTR) x-ray fluorescence (X RF) and spectroscopy. The FTIR spectroscopy results suggested that there were no major chemical functional group transformation during irradiation. No change occurs by using low dose as 2.5 kGy. Also evaluation impact of radiation on liquid Samples (Aqueous solutions prepared in tow concentration of 1% and 5% wv that is by exposing the samples to the same dose of gamma rays) the effect of irradiation on it were investigated by using ultra violet spectroscopy ( UV.Vis), results showed that low dose has steeply effect in solutions specially in low concentration, it was more pronoun than that in high concentration, high dose has made change similar to that it made in powder. Also for both concentrations of liquid samples and for solutions made of irradiated powder pH measured and viscosity which used in investigations of molecular weight of liquid and powder, comparing the results of impact in the form of powder with the results of effects in the solutions found that the effects of

  4. Electronic polarizability, optical properties and chemical bonding of oxide glasses

    International Nuclear Information System (INIS)

    Full text: The current status of the polarizability approach to glass science has been considered. Four groups of oxide glasses have been established: glasses formed by two glass-forming acidic oxides; glasses formed by glass-forming acidic oxide and modifier's basic oxide; glasses formed by glass-forming acidic and conditional glass-forming basic oxide; glasses formed by two basic oxides. The role of the electronic ion polarizability, αo2.(n0) as well as of the average single bond strength, BMo, as basic parameters of linear and nonlinear optical properties of oxide glasses has been emphasized. More acidic glasses possess large BMo (450-350 kJ/mol) which means participation of an average oxide ion in more covalent M-BO (bridging oxygen) bonds such as P-O, Si-O, and Ge-O. The decrease of BM0 could be attributed to formation of M-NBO (non-bridging oxygen) or other bonds with increased ionicity such as La-O, Pb-O, etc. The smallest values of BM0 at about 250 kJ/mol have been obtained for basic tellurite and bismuthate glasses. It has been assumed that these values could be associated with the presence of Te-NBO, Te-BO, and Bi-BO chemical bonds with large ionic contribution. The results obtained probably provide a good basis for prediction of the type of bonding in oxide glasses based on refractive index as well as for prediction of new nonlinear optical materials

  5. Physical and chemical properties of industrial mineral oils affecting lubrication

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, D.; Herguth, W.R. [Herguth Laboratories, Inc., Vallejo, CA (United States)

    1996-02-01

    The lubricating properties of mineral oils, and contaminants which affect those properties, are discussed. A contaminant is any material not in the original fresh oil, whether it is generated within the system or ingested. 5 refs.

  6. Chemical properties of surface peat on forest land in Estonia

    Directory of Open Access Journals (Sweden)

    R. Kõlli

    2010-10-01

    Full Text Available The chemical properties of surface peat cover (SPC were studied in the context of Estonian pedoecological conditions. SPC comprises the superficial layers of fens (Group 1 and transitional bogs (Group 2, together with slightly acid peaty mull / strongly acid peaty moder (Group 3 and very strongly acid peaty mor (Group 4 layers overlying mineral soils. Thus, it spans organic soils, namely Histosols (Groups 1 and 2; together with Histic Gleysols (Group 3 and Histic Podzols (Group 4, which are developmentally intermediate between organic and mineral soils. Moderately acid eutrophic (Group 1 and very strongly acid mesotrophic (Group 2 peats (forest litter layers excluded were uniformly characterised up to 40 cm depth; whereas for Groups 3 and 4 we examined the full thickness of available peat layers, which ranged from 10 to 30 cm. The results show that Al, K and heavy metal contents are significantly higher and organic carbon content is lower in Histic Soils (3, 4 than in Histosols (1, 2. The amounts of Ca, Mg, Mn and Fe are significantly higher and C:N ratio, exchangeable acidity and content of free H+ lower in less acidic (1, 3 than in more acidic (2, 4 soil types. The total concentration of elements (excluding heavy metals extracted by nitro-hydrochloric acid (aqua regia is considerably higher in less acidic soils, at 28–45 g kg-1 (1, 3 versus 10–12 g kg-1 (2, 4; and mean contents of individual elements decrease in the order Ca(51% > Fe(20% > S(10% ≥ Al(10% > Mg(3% ≥ P(3% > K(2% > Mn(1% > Na(<1%. The most abundant heavy metals are Pb (12–33 mg kg-1, Zn (7–41 mg kg-1, Cu (3–12 mg kg-1, Cr (2–23 mg kg-1 and Ni (2–8 mg kg-1; Cd and Hg contents are very low, ranging from 0.2 to 0.5 mg kg-1. The dominant exchangeable basic cations are Ca2+ (78–93% and Mg2+ (7–15%, and the peat contains much smaller amounts of K+ (1–6% and Na+ (<2%. The total exchangeable acidic cations (1–14 cmol kg-1 are dominated by H+ (51–83% and Al3

  7. Hydrogrossular (Katoite): Vibrational, Crystal-Chemical and Thermodynamic Properties

    Science.gov (United States)

    Dachs, E.; Geiger, C. A.

    2011-12-01

    There is great current interest in understanding interactions between H2O and its components and various Earth materials. Here, questions such as the bulk water content of the mantle, and what phases can incorporate OH- and in what concentrations come immediately to mind. In this regard, the hydrogarnet substitution (i.e., O4H4↔SiO4) has received special attention, because it is a verified mechanism for allowing the incorporation of OH- in garnet and possibly in other silicates as well. At relatively low temperatures there is complete solid solution between Ca3Al2Si3O12 and Ca3Al2O12H12. The latter, pure OH-containing end-member is termed katoite/hydrogrossular. Its crystal structure has been investigated by various workers using X-ray and neutron diffraction, including at high pressures. Little is known about its vibrational properties and its thermodynamic behavior is not fully understood. Thus, we studied the low temperature IR spectra and measured the heat capacity of katoite in order to investigate its vibrational, crystal-chemical and thermophysical properties. Katoite was synthesized hydrothermally in Au capsules at 250 °C and 3 kb water pressure. X-ray powder measurements show that about 98-99% katoite was obtained. Powder IR spectra were recorded between 298 K and 10 K. The spectra are considerably different in the high wavenumber region, where O-H stretching modes occur. At room temperature the IR-active O-H band located around 3662 cm-1 is broad and it narrows and shifts to higher wavenumbers and also develops structure below about 80 K. Concomitantly, additional weak intensity O-H bands located around 3600 cm-1 begin to appear and they become sharper and increase in intensity with further decreases in temperature. The spectra indicate that the vibrational behavior of individual OH groups and their collective interactions measurably affect the lattice dynamic (i.e. thermodynamic) behavior. The low temperature heat capacity behavior was investigated

  8. [Assessment of the relationship of properties of chemical compounds and their toxicity to a unified hygienic standardization for chemicals].

    Science.gov (United States)

    Trushkov, V F; Perminov, K A; Sapozhnikova, V V; Ignatova, O L

    2013-01-01

    The connection of thermodynamic properties and parameters of toxicity of chemical substances was determined. Obtained data are used for the evaluation of toxicity and hygienic rate setting of chemical compounds. The relationship between enthalpy and toxicity of chemical compounds has been established. Orthogonal planning of the experiment was carried out in the course of the investigations. Equation of unified hygienic rate setting in combined, complex, conjunct influence on the organism is presented. Prospects of determination of toxicity and methodology of unified hygienic rate setting in combined, complex, conjunct influence on the organism are presented

  9. [Assessment of the relationship of properties of chemical compounds and their toxicity to a unified hygienic standardization for chemicals].

    Science.gov (United States)

    Trushkov, V F; Perminov, K A; Sapozhnikova, V V; Ignatova, O L

    2013-01-01

    The connection of thermodynamic properties and parameters of toxicity of chemical substances was determined. Obtained data are used for the evaluation of toxicity and hygienic rate setting of chemical compounds. The relationship between enthalpy and toxicity of chemical compounds has been established. Orthogonal planning of the experiment was carried out in the course of the investigations. Equation of unified hygienic rate setting in combined, complex, conjunct influence on the organism is presented. Prospects of determination of toxicity and methodology of unified hygienic rate setting in combined, complex, conjunct influence on the organism are presented PMID:24003710

  10. Transport properties of chemically synthesized polypyrrole thin films

    OpenAIRE

    Bufon, C. C. Bof; Heinzel, T.

    2007-01-01

    The electronic transport in polypyrrole thin films synthesized chemically from the vapor phase is studied as a function of temperature as well as of electric and magnetic fields. We find distinct differences in comparison to the behavior of both polypyrrole films prepared by electrochemical growth as well as of the bulk films obtained from conventional chemical synthesis. For small electric fields F, a transition from Efros-Shklovskii variable range hopping to Arrhenius activated transport is...

  11. Potential Impacts of Spilled Hydraulic Fracturing Fluid Chemicals on Water Resources: Types, volumes, and physical-chemical properties of chemicals

    Science.gov (United States)

    Hydraulic fracturing (HF) fluid chemicals spilled on-site may impact drinking water resources. While chemicals generally make up <2% of the total injected fluid composition by mass, spills may have undiluted concentrations. HF fluids typically consist of a mixture of base flui...

  12. Effects of different chemical additives on biodiesel fuel properties and engine performance. A comparison review

    Directory of Open Access Journals (Sweden)

    Ali Obed Majeed

    2016-01-01

    Full Text Available Biodiesel fuel can be used as an alternative to mineral diesel, its blend up to 20% used as a commercial fuel for the existing diesel engine in many countries. However, at high blending ratio, the fuel properties are worsening. The feasibility of pure biodiesel and blended fuel at high blending ratio using different chemical additives has been reviewed in this study. The results obtained by different researchers were analysed to evaluate the fuel properties trend and engine performance and emissions with different chemical additives. It found that, variety of chemical additives can be utilised with biodiesel fuel to improve the fuel properties. Furthermore, the chemical additives usage in biodiesel is inseparable both for improving the cold flow properties and for better engine performance and emission control. Therefore, research is needed to develop biodiesel specific additives that can be adopted to improve the fuel properties and achieve best engine performance at lower exhaust emission effects.

  13. Machine Learning of Molecular Electronic Properties in Chemical Compound Space

    CERN Document Server

    Montavon, Grégoire; Gobre, Vivekanand; Vazquez-Mayagoitia, Alvaro; Hansen, Katja; Tkatchenko, Alexandre; Müller, Klaus-Robert; von Lilienfeld, O Anatole

    2013-01-01

    The combination of modern scientific computing with electronic structure theory can lead to an unprecedented amount of data amenable to intelligent data analysis for the identification of meaningful, novel, and predictive structure-property relationships. Such relationships enable high-throughput screening for relevant properties in an exponentially growing pool of virtual compounds that are synthetically accessible. Here, we present a machine learning (ML) model, trained on a data base of \\textit{ab initio} calculation results for thousands of organic molecules, that simultaneously predicts multiple electronic ground- and excited-state properties. The properties include atomization energy, polarizability, frontier orbital eigenvalues, ionization potential, electron affinity, and excitation energies. The ML model is based on a deep multi-task artificial neural network, exploiting underlying correlations between various molecular properties. The input is identical to \\emph{ab initio} methods, \\emph{i.e.} nucle...

  14. Physico-chemical properties of perturbed water: facts and enigmas

    Directory of Open Access Journals (Sweden)

    Vittorio Elia

    2012-09-01

    Full Text Available Background The study of extremely diluted and agitated substances and solutions is strictly linked with the analysis of properties of water perturbed using different systems. This study is about the determination of the physical-chemical parameters of water, after the perturbations described. Methods The perturbed water was obtained using the three different protocols: · EDS (Extremely Diluted Solutions. Obtained through an iterative process of successive dilutions and agitations. · IFW (Iteratively Filtered Water. Obtained through an iterative process of successive filtrations through sintered glass filters. · INW (Iteratively Nafionized Water. Obtained through an iterative process of successive drying and wetting of the Nafion polymer. The parameters under study are: electrical conductivity, χ / μS cm-1; heat of mixing with acid (HCl, ΔQmixHCl / J Kg-1 or basic (NaOH solutions, ΔQmixNaOH / J Kg-1 and pH. χ increases of up to two orders of magnitude, ΔQmixNaOH / J Kg-1 is exothermic and increases as the electrical conductivity increases, with a roughly linear trend, up to one order of magnitude. The analogous ΔQmixHCl / J Kg-1, on the contrary, is found to be exothermic or null depending on the protocol used. For the two protocol (EDS or IFW the pH is alkaline while for the third one (INW is quite acid and shows a very good linear correlation with logχ. The linear correlations hint at a single cause for the variation of the three very different physical- chemical parameters. Results and discussion Each protocol produces water exhibiting its own peculiarities, to the point that they can be considered different, albeit with the common element of a variation of the super-molecular structure of the water solvent. These three procedures capable of affecting water can be grouped together by means of a common work

  15. Influence of process parameters on the surface and chemical properties of activated carbon obtained from biochar by chemical activation.

    Science.gov (United States)

    Angın, Dilek; Altintig, Esra; Köse, Tijen Ennil

    2013-11-01

    Activated carbons were produced from biochar obtained through pyrolysis of safflower seed press cake by chemical activation with zinc chloride. The influences of process variables such as the activation temperature and the impregnation ratio on textural and chemical-surface properties of the activated carbons were investigated. Also, the adsorptive properties of activated carbons were tested using methylene blue dye as the targeted adsorbate. The experimental data indicated that the adsorption isotherms are well described by the Langmuir equilibrium isotherm equation. The optimum conditions resulted in activated carbon with a monolayer adsorption capacity of 128.21 mg g(-1) and carbon content 76.29%, while the BET surface area and total pore volume corresponded to 801.5m(2)g(-1) and 0.393 cm(3)g(-1), respectively. This study demonstrated that high surface area activated carbons can be prepared from the chemical activation of biochar with zinc chloride as activating agents. PMID:24080293

  16. Electronic and chemical properties of graphene-based structures:

    DEFF Research Database (Denmark)

    Vanin, Marco

    are easier to remove and therefore only zigzag edges are left. Finally, functionalized graphene has been investigated as catalyst for the electrochemical reduction of CO2 to chemical fuels and comparisons are made with traditional transition-metal surfaces. The investigated porphyrin-like structures...... are attractive candidates although issues regarding the poisoning of the active site remain to be addressed....

  17. Medicinal chemical properties of successful central nervous system drugs.

    Science.gov (United States)

    Pajouhesh, Hassan; Lenz, George R

    2005-10-01

    Fundamental physiochemical features of CNS drugs are related to their ability to penetrate the blood-brain barrier affinity and exhibit CNS activity. Factors relevant to the success of CNS drugs are reviewed. CNS drugs show values of molecular weight, lipophilicity, and hydrogen bond donor and acceptor that in general have a smaller range than general therapeutics. Pharmacokinetic properties can be manipulated by the medicinal chemist to a significant extent. The solubility, permeability, metabolic stability, protein binding, and human ether-ago-go-related gene inhibition of CNS compounds need to be optimized simultaneously with potency, selectivity, and other biological parameters. The balance between optimizing the physiochemical and pharmacokinetic properties to make the best compromises in properties is critical for designing new drugs likely to penetrate the blood brain barrier and affect relevant biological systems. This review is intended as a guide to designing CNS therapeutic agents with better drug-like properties. PMID:16489364

  18. Development of pure component property models for chemical product-process design and analysis

    DEFF Research Database (Denmark)

    Hukkerikar, Amol Shivajirao

    Property prediction models based on the group-contribution+ (GC+) approach have been developed to provide reliable predictions of pure component properties together with uncertainties of predicted property values which is much needed information in performing chemical product and process design...... into ProPred®, a property estimation toolbox of Integrated Computer Aided System, ICAS®, developed at CAPEC, DTU. Finally, a methodology for performing sensitivity analysis of process design due to uncertainties of property estimates is presented. This methodology allows the user to evaluate the effects...... and analysis of sustainable chemical processes. For developing property models, a systematic methodology for property modeling and uncertainty analysis is employed. The methodology includes a parameter estimation step to determine parameters of the property model and an uncertainty analysis step to establish...

  19. Tuning the NLO properties of polymethineimine chains by chemical substitution

    Energy Technology Data Exchange (ETDEWEB)

    Medved’, Miroslav, E-mail: miroslav.medved@umb.sk [Department of Chemistry, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, SK-97400 Banská Bystrica (Slovakia); Jacquemin, Denis [CEISAM, UMR CNRS 6230, BP 92208, Université de Nantes, 2, rue de la Houssinière, 44322 Nantes Cedex 3 (France); Institut Universitaire de France, 103, bd Saint-Michel, F-75005 Paris Cedex 05 (France)

    2013-03-29

    Highlights: ► Properties of the most stable isomers of polymethineimine (PMI) are investigated. ► 2nd order NLO properties of experimentally known PMI derivatives are determined. ► Structure-property relationships are unraveled for several series of oligomers. ► Performance of long-range corrected DFT methods is assessed. - Abstract: Structure and molecular electronic properties including dipole moment, polarizability and first hyperpolarizability of polymethineimine (PMI) oligomers (up to hexadecamers) and its experimentally known amino-, methyl-, and cyano-derivatives are investigated using several ab initio methods (HF, MP2 and DFT). It is shown that side-chain substitutions have significant effects both on the structure and molecular properties of PMI chains. Depending on the substitution, two types of structures have been identified. The first is characterized by a bent skeleton and encompasses PMI, polyacetonitrile (PAcN), and polycyanonitrile (PCN). The second, represented by polyaminonitrile (PAN), remains quasi-linear with the plane of the unit cell (UC) only slightly rotating around the longitudinal molecular axis. These structural differences are also reflected in molecular properties; while in case of PMI, PAcN, and PCN the longitudinal component of properties (reduced per UC) reaches its maximum value for medium-size oligomers and then decreases for longer chains, the linear and nonlinear properties of PAN steadily increase towards the polymeric limit. In addition, we have assessed the performances of long-range corrected DFT functionals (LR-DFT), namely LC-BLYP, CAM-B3LYP, and ωB97X within the present framework: they provide results in qualitative agreement with MP2, a success not reached with B3LYP.

  20. Physical and chemical properties of San Francisco Bay waters, 1969-1976 (NODC Accession 8400194)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — One magnetic tape containing the physical and chemical properties of San Francisco Bay waters was forwarded to NODC by Mr. Richard Smith of the U.S Geological...

  1. Tuning the NLO properties of polymethineimine chains by chemical substitution

    Science.gov (United States)

    Medved', Miroslav; Jacquemin, Denis

    2013-03-01

    Structure and molecular electronic properties including dipole moment, polarizability and first hyperpolarizability of polymethineimine (PMI) oligomers (up to hexadecamers) and its experimentally known amino-, methyl-, and cyano-derivatives are investigated using several ab initio methods (HF, MP2 and DFT). It is shown that side-chain substitutions have significant effects both on the structure and molecular properties of PMI chains. Depending on the substitution, two types of structures have been identified. The first is characterized by a bent skeleton and encompasses PMI, polyacetonitrile (PAcN), and polycyanonitrile (PCN). The second, represented by polyaminonitrile (PAN), remains quasi-linear with the plane of the unit cell (UC) only slightly rotating around the longitudinal molecular axis. These structural differences are also reflected in molecular properties; while in case of PMI, PAcN, and PCN the longitudinal component of properties (reduced per UC) reaches its maximum value for medium-size oligomers and then decreases for longer chains, the linear and nonlinear properties of PAN steadily increase towards the polymeric limit. In addition, we have assessed the performances of long-range corrected DFT functionals (LR-DFT), namely LC-BLYP, CAM-B3LYP, and ωB97X within the present framework: they provide results in qualitative agreement with MP2, a success not reached with B3LYP.

  2. Chemical constituents of the genus Prunus and their medicinal properties.

    Science.gov (United States)

    Poonam, V; Raunak; Kumar, G; Reddy L, C S; Jain, R; Sharma, S K; Prasad, A K; Parmar, V S

    2011-01-01

    Prunus is a genus of trees and shrubs, including the plums, cherries, peaches, apricots and almonds. Nearly five hundred seventy chemical compounds have so far been isolated from several Prunus species. This comprehensive review summarizes the isolation of chemical compounds reported during the period 1908 to June 2010. As per scrutiny of literature, we did not find any review on the chemistry or biology of genus Prunus or on the biological activities of its constituents. Extensive work has been done at the Department of Chemistry, University of Delhi by several groups on the isolation, identification, biological activity evaluation and synthesis of a large number of novel compounds from different Prunus species during the the last six decades (1940-2000), primarly by Seshadri, Nagarajan and Parmar et al. on P. domestica, P. cerasus, P. cerasoides, P. puddum and P. communis. This comprehensive review will benefit a large number of researchers in the fields of chemistry, botany, drug industries and pharmacology. PMID:21831039

  3. Stevia rebaudiana Bertoni – chemical composition and functional properties

    OpenAIRE

    Katarzyna Marcinek; Zbigniew Krejpcio

    2015-01-01

    Sweetleaf (Stevia rebaudiana Bertoni), currently investigated by many researchers, has been known and used for more than a thousand years indigenous tribes of South America, who called it “kaa-hee” (“sweet herb”). Thanks to its chemical composition and processability sweetleaf may be an alternative for synthetic sweeteners. Nutritional and health-promoting aspects of Stevia rebaudiana are presently being studied in many research centres. The aim of this study is to pre...

  4. Properties of Random Complex Chemical Reaction Networks and Their Relevance to Biological Toy Models

    OpenAIRE

    Bigan, Erwan; Steyaert, Jean-Marc; Douady, Stéphane

    2013-01-01

    We investigate the properties of large random conservative chemical reaction networks composed of elementary reactions endowed with either mass-action or saturating kinetics, assigning kinetic parameters in a thermodynamically-consistent manner. We find that such complex networks exhibit qualitatively similar behavior when fed with external nutrient flux. The nutrient is preferentially transformed into one specific chemical that is an intrinsic property of the network. We propose a self-consi...

  5. Soil chemical properties related to acidity under successive pig slurry application

    OpenAIRE

    Cledimar Rogério Lourenzi; Carlos Alberto Ceretta; Leandro Souza da Silva; Gustavo Trentin; Eduardo Girotto; Felipe Lorensini; Tadeu Luis Tiecher; Gustavo Brunetto

    2011-01-01

    Pig slurry application as soil manure can alter the chemical properties of the soil and affect its acidity, modifying the environment for crop growth and development. The objective of this study was to evaluate the chemical properties related to soil acidity subjected to successive applications of pig slurry. The experiment was conducted in May 2000, in an experimental area of the Federal University of Santa Maria (UFSM) under no-tillage and lasted until January 2008. Nineteen surface applica...

  6. Multivariate analysis of chemical properties in oxisols with different levels of intervention agricultural

    OpenAIRE

    Camacho-Tamayo, Jesús H.; Luengas-Gómez, Carlos; Fabio R Leiva

    2010-01-01

    Human intervention in agricultural production affects directly soil quality by promoting changes in physical and chemical properties through the use of fertilizers, correctives and tillage practices (Brachiria and corn- soybean). The aim of this study was to evaluate changes in the chemical properties of two Oxisols (Typic Hapludox y Typic Haplustox) with different intervention levels, in the municipality of Puerto Lopez (Meta-Colombia). Samples were taken at 42 points, spaced 25 m perpendicu...

  7. Changes in Chemical and Sensory Properties of Migaki-Nishin (Dried Herring Fillet) during Drying

    OpenAIRE

    Shah, A.K.M. Azad; Tokunaga, C; M Ogasawara; Kurihara, H.; Takahashi, Koretaro

    2009-01-01

    Migaki-nishin is a Japanese term that refers to dried herring fillets. It is widely consumed in Japan due to its characteristic flavor enhancing properties. This study was conducted to investigate the changes in chemical and sensory properties of migaki-nishin during drying. Chemical analyses showed that extractive nitrogen and amount of peptides increased significantly (P < 0.05) up to the eighth day of drying and then slightly decreased by the tenth day. Glutamic acid, alanine, glycine, and...

  8. Effect of Chemicals on Geotechnical Properties of Clay Liners: A Review

    OpenAIRE

    Seracettin Arasan

    2010-01-01

    This study presents a review of recent research on the geotechnical properties (consistency limits, hydraulic conductivity, shear strength, swelling, and compressibility) of clay liners conducted with organic and inorganic chemicals. Due to its low permeability, a clay liner is the main material used in solid waste disposal landfills. It is exposed there to various chemical, biological and physical events, and the clay liner is affected by the resulting leachate. The geotechnical properties o...

  9. Physical-chemical properties and sorption characteristics of peat

    OpenAIRE

    Delicato, Domenico M. S

    1996-01-01

    The physicochemical properties of peat fibre, peat moss and two processed forms of peat moss were studied. The properties examined included thermal analysis (by T G A and DSC), IR spectroscopy and the zero point o f charge From D S C analysis it was found that the ignition point for the peat materials occurred at about 200°C. Above this temperature there were three exothermic peaks recorded, the first at c 333°C corresponded to the decomposition of cellulose, the second at c 438°C to the deco...

  10. Amphibian and benthic macroinvertebrate response to physical and chemical properties of Themi River, Arusha, Tanzania

    OpenAIRE

    Lyimo, Emmanuel

    2012-01-01

    I hypothesized that variation in physical and chemical properties and habitat destruction of the Themi River as a result of human activities would affect abundance and diversity of amphibian and benthic macroinvertebrates. Variation in habitat physical and chemical conditions, and amphibian and benthic macroinvertebrate diversity and abundance were assessed in the Themi River of Arusha municipality. These physical, chemical and biological conditions were assessed at forty sampling stations...

  11. Properties of Chemically Combusted Calcium Carbide Residue and Its Influence on Cement Properties

    Directory of Open Access Journals (Sweden)

    Hongfang Sun

    2015-02-01

    Full Text Available Calcium carbide residue (CCR is a waste by-product from acetylene gas production. The main component of CCR is Ca(OH2, which can react with siliceous materials through pozzolanic reactions, resulting in a product similar to those obtained from the cement hydration process. Thus, it is possible to use CCR as a substitute for Portland cement in concrete. In this research, we synthesized CCR and silica fume through a chemical combustion technique to produce a new reactive cementitious powder (RCP. The properties of paste and mortar in fresh and hardened states (setting time, shrinkage, and compressive strength with 5% cement replacement by RCP were evaluated. The hydration of RCP and OPC (Ordinary Portland Cement pastes was also examined through SEM (scanning electron microscope. Test results showed that in comparison to control OPC mix, the hydration products for the RCP mix took longer to formulate. The initial and final setting times were prolonged, while the drying shrinkage was significantly reduced. The compressive strength at the age of 45 days for RCP mortar mix was found to be higher than that of OPC mortar and OPC mortar with silica fume mix by 10% and 8%, respectively. Therefore, the synthesized RCP was proved to be a sustainable active cementitious powder for the strength enhanced of building materials, which will result in the diversion of significant quantities of this by-product from landfills.

  12. 40 CFR 716.50 - Reporting physical and chemical properties.

    Science.gov (United States)

    2010-07-01

    .... (g) Dissociation constant. (h) Degradation by photochemical mechanisms—aquatic and atmospheric. (i... they investigated one or more of the following properties: (a) Water solubility. (b) Adsorption/desorption on particulate surfaces, e.g., soil. (c) Vapor pressure. (d) Octanol/water partition...

  13. Chemical structures and thermochemical properties of bagasse lignin

    Institute of Scientific and Technical Information of China (English)

    Wu Shu-bin; Guo Yi-li; Wang Shao-guang; Li Meng-shi

    2006-01-01

    The chemical structures of bagasse EMAL (enzymatic hydrolysis/mild acidolysis lignin) were revealed quantitatively with 31P-NMR, DFRC (derivatization followed by reductive cleavage). The thermochemical characteristics of bagasse and bagasse EMAL were evaluated with thermogravimetry. The results show that bagasse EMAL is mainly formed by the phenolic hydroxyl group of guaiacyl and syringyl units. The DBDO content in bagasse EMAL was found to be 0.180 mmol·g-1. The decomposition characteristics of bagasse EMAL under elevated temperature were much different from that of bagasse.

  14. USE OF SCALED SEMIVARIOGRAMS IN THE PLANNING SAMPLE OF SOIL CHEMICAL PROPERTIES IN SOUTHERN AMAZONAS, BRAZIL

    Directory of Open Access Journals (Sweden)

    Ivanildo Amorim de Oliveira

    2015-02-01

    Full Text Available The lack of information concerning the variability of soil properties has been a major concern of researchers in the Amazon region. Thus, the aim of this study was to evaluate the spatial variability of soil chemical properties and determine minimal sampling density to characterize the variability of these properties in five environments located in the south of the State of Amazonas, Brazil. The five environments were archaeological dark earth (ADE, forest, pasture land, agroforestry operation, and sugarcane crop. Regular 70 × 70 m mesh grids were set up in these areas, with 64 sample points spaced at 10 m distance. Soil samples were collected at the 0.0-0.1 m depth. The chemical properties of pH in water, OM, P, K, Ca, Mg, H+Al, SB, CEC, and V were determined at these points. Data were analyzed by descriptive and geostatistical analyses. A large part of the data analyzed showed spatial dependence. Chemical properties were best fitted to the spherical model in almost all the environments evaluated, except for the sugarcane field with a better fit to the exponential model. ADE and sugarcane areas had greater heterogeneity of soil chemical properties, showing a greater range and higher sampling density; however, forest and agroforestry areas had less variability of chemical properties.

  15. Magnetic Properties of Chemically Synthesized FePt Nanoparticles

    Science.gov (United States)

    Harrell, J. W.

    2005-03-01

    Chemically synthesized FePt nanoparticles have attracted considerable attention in recent years because of their potential use in ultra-high density magnetic recording media. In the original procedure described by Sun et al., the as-synthesized nanoparticles have the fcc phase and must be thermally annealed to achieve the high-anisotropy L10 phase [1]. We have been addressing some of the materials problems associated with obtaining the L10 phase. These include lowering the ordering temperature, reducing sintering during annealing, orienting the easy axes, and understanding the size effect on chemical ordering. Additive Au and Ag significantly lower the ordering temperature, while additive Cr and Cu increase the ordering temperature; however, the onset of ordering is correlated with sintered grain growth. Sintering can be reduced by encapsulating the nanoparticles with a shell such as silicon oxide or copper. Easy-axis orientation has been achieved using L10 FePt nanoparticles that were directly synthesized using a high-temperature solvent [2]. The nanoparticles were dispersed in a PVC binder and oriented by drying the dispersion in a magnetic field. [1] S. Sun et al., Science 287, 1989 (2000). [2] S. Kang et al., Appl Phys. Lett. (in press).

  16. Chemical and physical properties of bone cement for vertebroplasty

    Directory of Open Access Journals (Sweden)

    Po-Liang Lai

    2013-08-01

    Full Text Available Vertebral compression fracture is the most common complication of osteoporosis. It may result in persistent severe pain and limited mobility, and significantly impacts the quality of life. Vertebroplasty involves a percutaneous injection of bone cement into the collapsed vertebrae by fluorescent guide. The most commonly used bone cement in percutaneous vertebroplasty is based on the polymerization of methylmethacrylate monomers to polymethylmethacrylate (PMMA polymers. However, information on the properties of bone cement is mostly published in the biomaterial sciences literature, a source with which the clinical community is generally unfamiliar. This review focuses on the chemistry of bone cement polymerization and the physical properties of PMMA. The effects of altering the portions and contents of monomer liquid and polymer powders on the setting time, polymerization temperature, and compressive strength of the cement are also discussed. This information will allow spine surgeons to manipulate bone cement characteristics for specific clinical applications and improve safety.

  17. Medicinal Chemical Properties of Successful Central Nervous System Drugs

    OpenAIRE

    Pajouhesh, Hassan; Lenz, George R.

    2005-01-01

    Summary: Fundamental physiochemical features of CNS drugs are related to their ability to penetrate the blood-brain barrier affinity and exhibit CNS activity. Factors relevant to the success of CNS drugs are reviewed. CNS drugs show values of molecular weight, lipophilicity, and hydrogen bond donor and acceptor that in general have a smaller range than general therapeutics. Pharmacokinetic properties can be manipulated by the medicinal chemist to a significant extent. The solubility, permeabi...

  18. Structural, chemical and magnetic properties of secondary phases in Co-doped ZnO

    DEFF Research Database (Denmark)

    Ney, A; Kovács, András; Ney, V;

    2011-01-01

    , chemical and magnetic properties of Co-doped ZnO samples. It can be established on a quantitative basis that the superparamagnetic (SPM) behavior observed by integral superconducting quantum interference device magnetometry is not an intrinsic property of the material but stems from precipitations...

  19. Online Data Resources in Chemical Engineering Education: Impact of the Uncertainty Concept for Thermophysical Properties

    Science.gov (United States)

    Kim, Sun Hyung; Kang, Jeong Won; Kroenlein, Kenneth; Magee, Joseph W.; Diky, Vladimir; Muzny, Chris D.; Kazakov, Andrei F.; Chirico, Robert D.; Frenkel, Michael

    2013-01-01

    We review the concept of uncertainty for thermophysical properties and its critical impact for engineering applications in the core courses of chemical engineering education. To facilitate the translation of developments to engineering education, we employ NIST Web Thermo Tables to furnish properties data with their associated expanded…

  20. Chemical properties of Pu, Am, Np, I, and Tc and their influence on migration

    International Nuclear Information System (INIS)

    The migrational behavior of waste materials from a repository will depend upon the chemical characteristics of the various species and upon the chemical environment in which they are found. Therefore, it is important to understand the properties of these various species and it is also important to understand how these properties influence their behavior. The results of our empirical study of the migration of Pu, Am, Np, I, and Tc can be related to the chemical properties of these elements and show that the higher oxidation states are anionic and rapidly migrating. These results indicate that the chemical form and milieu are of primary importance. It has been found that the cationic species migrate much more slowly and it was seen that several minerals act to bind even the anionic or oxidized forms

  1. Thermodynamic properties of Cu–Zr melts: The role of chemical interaction

    Energy Technology Data Exchange (ETDEWEB)

    Kulikova, T.V.; Majorova, A.V.; Shunyaev, K.Yu. [Institute of Metallurgy, Ural Division of Russian Academy of Sciences, Amudsena str. 101, 620016 Ekaterinburg (Russian Federation); Ryltsev, R.E., E-mail: rrylcev@mail.ru [Institute of Metallurgy, Ural Division of Russian Academy of Sciences, Amudsena str. 101, 620016 Ekaterinburg (Russian Federation); Ural Federal University, Mira str. 19, 620002 Ekaterinburg (Russian Federation)

    2015-06-15

    General statistical model is applied to analyze the role of chemical interaction in associated systems. We show that, at certain conditions, chemical interaction between associates may be not essential above a distectic point and so the model of ideal associated solutions is a good approximation for describing high temperature properties of associated system with chemical interaction. Within the frames of such conception, we calculate thermodynamic properties of Cu–Zr system in liquid state. The enthalpies of formation of Cu–Zr intermetallic compounds were redefined by using matching procedure taking into account the additive manifestation of chemical interaction. We conclude that simple model which is free of adjusting parameters allows us to calculate thermodynamic properties of Cu–Zr melts with quite good accuracy.

  2. Chemical and molecular properties of irradiated starch extrudates

    International Nuclear Information System (INIS)

    Corn starch samples containing 0, 25, 50, and 70% amylose were gamma-irradiated at 0 (native), 5, 10, 20, and 30 kGy. All starch samples were extrusion cooked at 140 degrees C barrel temperature, 140 rpm screw speed, and 18% moisture content (db) using a C. W. Brabender single-screw extruder. Starches irradiated at a 20-kGy dosage were extrusion cooked with and without hydrogen peroxide, potassium persulfate, or ceric ammonium nitrate. The quantity of free radicals produced on the starch increased with increasing irradiation dosages (0-30 kGy). Stability of the free radicals was greater for high-amylose starches than for those with low amylose. Extrusion-cooked starches had traces of free radical activity. Acidity of the irradiated starches increased (pH decreased) with increasing irradiation dosages. Gel permeation chromatographic separation of variously treated starches gave three fractions. Fraction I, mostly amylopectin, eluted at the void volume, whereas fraction II, mostly amylose, eluted at the latter part of the gel. Fraction 0, degraded products of amylopectin and amylose, mostly eluted closer to the total volume of the gel. Fraction I quantities of irradiated starches decreased with increasing irradiation dosages, whereas fraction II and III quantities correspondingly increased. Native starches with 0% amylose exhibited more than a fourfold decrease in fraction I content, whereas 70% amylose native starches showed less than a twofold decrease due to increasing irradiation dosages from 0 to 30 kGy. Extrusion cooking accelerated the degradation of fraction I for 0% amylose starches more than for 70% amylose starches. Both 2.5 and 5% concentrations of chemical additives caused excessive degradation of fraction I of starches irradiated at 20 kGy, consequently increasing reducing powers. Ceric ammonium nitrate caused the highest decrease in the iodine binding capacity of the starches. Fraction I clearly suffered more degradation due to irradiation, extrusion

  3. Effects of Hygrothermal Cycling on the Chemical, Thermal, and Mechanical Properties of 862/W Epoxy Resin

    Science.gov (United States)

    Miller, Sandi G.; Roberts, Gary D.; Copa, Christine C.; Bail, Justin L.; Kohlman, Lee W.; Binienda, Wieslaw K.

    2011-01-01

    The hygrothermal aging characteristics of an epoxy resin were characterized over 1 year, which included 908 temperature and humidity cycles. The epoxy resin quickly showed evidence of aging through color change and increased brittleness. The influence of aging on the material s glass transition temperature (Tg) was evaluated by Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). The Tg remained relatively constant throughout the year long cyclic aging profile. The chemical composition was monitored by Fourier Transform Infrared Spectroscopy (FTIR) where evidence of chemical aging and advancement of cure was noted. The tensile strength of the resin was tested as it aged. This property was severely affected by the aging process in the form of reduced ductility and embrittlement. Detailed chemical evaluation suggests many aging mechanisms are taking place during exposure to hygrothermal conditions. This paper details the influence of processes such as: advancement of cure, chemical degradation, and physical aging on the chemical and physical properties of the epoxy resin.

  4. Mechanical and Chemical Properties of Bamboo/Glass Fibers Reinforced Polyester Composites

    OpenAIRE

    K.Sudha Madhuri,; H.Raghavendra Rao

    2016-01-01

    The chemical resistance of Bamboo/Glass reinforced Polyester hybrid composites to acetic acid, Nitric acid, Hydrochloric acid, Sodium hydroxide, Sodium carbonate, Benzene, Toluene, Carbon tetrachloride and Water was studied. The tensile and impact properties of these composites were also studied. The effect of alkali treatment of bamboo fibers on these properties was studied. It was observed that the tensile and impact properties of the hybrid composites increase with glass fiber ...

  5. Nanoscale chemical interaction enhances the physical properties of bioglass composites.

    Science.gov (United States)

    Ravarian, Roya; Zhong, Xia; Barbeck, Mike; Ghanaati, Shahram; Kirkpatrick, Charles James; Murphy, Ciara M; Schindeler, Aaron; Chrzanowski, Wojciech; Dehghani, Fariba

    2013-10-22

    Bioglasses are favorable biomaterials for bone tissue engineering; however, their applications are limited due to their brittleness. In addition, the early failure in the interface is a common problem of composites of bioglass and a polymer with high mechanical strength. This effect is due to the phase separation, nonhomogeneous mixture, nonuniform mechanical strength, and different degradation properties of two compounds. To address these issues, in this study a nanoscale interaction between poly(methyl methacrylate) (PMMA) and bioactive glass was formed via silane coupling agent (3-trimethoxysilyl)propyl methacrylate (MPMA). A monolith was produced at optimum composition from this hybrid by the sol-gel method at 50 °C with a rapid gelation time (hybrid. The in vivo studies in mice demonstrated that the integrity of the hybrids was maintained in subcutaneous implantation. They induced mainly a mononuclear phagocytic tissue reaction with a low level of inflammation, while bioglass provoked a tissue reaction with TRAP-positive multinucleated giant cells. These results demonstrated that the presence of a nanoscale interaction between bioglass and PMMA affects the properties of bioglass and broadens its potential applications for bone replacement.

  6. Chemical, Mineralogical, and Morphological Properties of Steel Slag

    Directory of Open Access Journals (Sweden)

    Irem Zeynep Yildirim

    2011-01-01

    Full Text Available Steel slag is a byproduct of the steelmaking and steel refining processes. This paper provides an overview of the different types of steel slag that are generated from basic-oxygen-furnace (BOF steelmaking, electric-arc-furnace (EAF steelmaking, and ladle-furnace steel refining processes. The mineralogical and morphological properties of BOF and electric-arc-furnace-ladle [EAF(L] slag samples generated from two steel plants in Indiana were determined through X-Ray Diffraction (XRD analyses and Scanning Electron Microscopy (SEM studies. The XRD patterns of both BOF and EAF(L slag samples were very complex, with several overlapping peaks resulting from the many minerals present in these samples. The XRD analyses indicated the presence of free MgO and CaO in both the BOF and EAF(L slag samples. SEM micrographs showed that the majority of the sand-size steel slag particles had subangular to angular shapes. Very rough surface textures with distinct crystal structures were observed on the sand-size particles of BOF and EAF(L slag samples under SEM. The characteristics of the steel slag samples considered in this study are discussed in the context of a detailed review of steel slag properties.

  7. Nanoscale chemical interaction enhances the physical properties of bioglass composites.

    Science.gov (United States)

    Ravarian, Roya; Zhong, Xia; Barbeck, Mike; Ghanaati, Shahram; Kirkpatrick, Charles James; Murphy, Ciara M; Schindeler, Aaron; Chrzanowski, Wojciech; Dehghani, Fariba

    2013-10-22

    Bioglasses are favorable biomaterials for bone tissue engineering; however, their applications are limited due to their brittleness. In addition, the early failure in the interface is a common problem of composites of bioglass and a polymer with high mechanical strength. This effect is due to the phase separation, nonhomogeneous mixture, nonuniform mechanical strength, and different degradation properties of two compounds. To address these issues, in this study a nanoscale interaction between poly(methyl methacrylate) (PMMA) and bioactive glass was formed via silane coupling agent (3-trimethoxysilyl)propyl methacrylate (MPMA). A monolith was produced at optimum composition from this hybrid by the sol-gel method at 50 °C with a rapid gelation time (hybrid. The in vivo studies in mice demonstrated that the integrity of the hybrids was maintained in subcutaneous implantation. They induced mainly a mononuclear phagocytic tissue reaction with a low level of inflammation, while bioglass provoked a tissue reaction with TRAP-positive multinucleated giant cells. These results demonstrated that the presence of a nanoscale interaction between bioglass and PMMA affects the properties of bioglass and broadens its potential applications for bone replacement. PMID:24001050

  8. Controlling Properties and Cytotoxicity of Chitosan Nanocapsules by Chemical Grafting

    Science.gov (United States)

    De Matteis, Laura; Alleva, Maria; Serrano-Sevilla, Inés; García-Embid, Sonia; Stepien, Grazyna; Moros, María; de la Fuente, Jesús M.

    2016-01-01

    The tunability of the properties of chitosan-based carriers opens new ways for the application of drugs with low water-stability or high adverse effects. In this work, the combination of a nanoemulsion with a chitosan hydrogel coating and the following poly (ethylene glycol) (PEG) grafting is proven to be a promising strategy to obtain a flexible and versatile nanocarrier with an improved stability. Thanks to chitosan amino groups, a new easy and reproducible method to obtain nanocapsule grafting with PEG has been developed in this work, allowing a very good control and tunability of the properties of nanocapsule surface. Two different PEG densities of coverage are studied and the nanocapsule systems obtained are characterized at all steps of the optimization in terms of diameter, Z potential and surface charge (amino group analysis). Results obtained are compatible with a conformation of PEG molecules laying adsorbed on nanoparticle surface after covalent linking through their amino terminal moiety. An improvement in nanocapsule stability in physiological medium is observed with the highest PEG coverage density obtained. Cytotoxicity tests also demonstrate that grafting with PEG is an effective strategy to modulate the cytotoxicity of developed nanocapsules. Such results indicate the suitability of chitosan as protective coating for future studies oriented toward drug delivery. PMID:27706041

  9. Prediction of Wine Sensorial Quality by Routinely Measured Chemical Properties

    Directory of Open Access Journals (Sweden)

    Bednárová Adriána

    2014-12-01

    Full Text Available The determination of the sensorial quality of wines is of great interest for wine consumers and producers since it declares the quality in most of the cases. The sensorial assays carried out by a group of experts are time-consuming and expensive especially when dealing with large batches of wines. Therefore, an attempt was made to assess the possibility of estimating the wine sensorial quality with using routinely measured chemical descriptors as predictors. For this purpose, 131 Slovenian red wine samples of different varieties and years of production were analysed and correlation and principal component analysis were applied to find inter-relations between the studied oenological descriptors. The method of artificial neural networks (ANNs was utilised as the prediction tool for estimating overall sensorial quality of red wines. Each model was rigorously validated and sensitivity analysis was applied as a method for selecting the most important predictors. Consequently, acceptable results were obtained, when data representing only one year of production were included in the analysis. In this case, the coefficient of determination (R2 associated with training data was 0.95 and that for validation data was 0.90. When estimating sensorial quality in categorical form, 94 % and 85 % of correctly classified samples were achieved for training and validation subset, respectively.

  10. Examination of lignocellulosic fibers for chemical, thermal, and separations properties: Addressing thermo-chemical stability issues

    Science.gov (United States)

    Johnson, Carter David

    Natural fiber-plastic composites incorporate thermoplastic resins with fibrous plant-based materials, sometimes referred to as biomass. Pine wood mill waste has been the traditional source of natural fibrous feedstock. In anticipation of a waste wood shortage other fibrous biomass materials are being investigated as potential supplements or replacements. Perennial grasses, agricultural wastes, and woody biomass are among the potential source materials. As these feedstocks share the basic chemical building blocks; cellulose, hemicellulose, and lignin, they are collectively called lignocellulosics. Initial investigation of a number of lignocellulosic materials, applied to fiber-plastic composite processing and material testing, resulted in varied results, particularly response to processing conditions. Less thermally stable lignocellulosic filler materials were physically changed in observable ways: darkened color and odor. The effect of biomass materials' chemical composition on thermal stability was investigated an experiment involving determination of the chemical composition of seven lignocellulosics: corn hull, corn stover, fescue, pine, soy hull, soy stover, and switchgrass. These materials were also evaluated for thermal stability by thermogravimetric analysis. The results of these determinations indicated that both chemical composition and pretreatment of lignocellulosic materials can have an effect on their thermal stability. A second study was performed to investigate what effect different pretreatment systems have on hybrid poplar, pine, and switchgrass. These materials were treated with hot water, ethanol, and a 2:1 benzene/ethanol mixture for extraction times of: 1, 3, 6, 12, and 24 hours. This factorial experiment demonstrated that both extraction time and medium have an effect on the weight percent of extractives removed from all three material types. The extracted materials generated in the above study were then subjected to an evaluation of thermal

  11. Investigation of the redox property of a metalloprotein layer self-assembled on various chemical linkers.

    Science.gov (United States)

    Chung, Yong-Ho; Lee, Taek; Min, Junhong; Choi, Jeong-Woo

    2011-10-01

    Myogloblin, a well-known metalloprotein, was immobilized on a gold surface using various chemical linkers to investigate the length effect of chemical linker on the electron transfer in protein layers, because chemical linkers play roles in the pathway that transfers the electron from the protein to the gold substrate and act as protein immobilization reagents. Chemical linkers with 2, 6, 11, and 16 carbons were utilized to confirm length-effects. The immobilization of protein and chemical linker was validated with surface plasmon resonance (SPR) and atomic force microscopy (AFM). The electrochemical property was evaluated by cyclic voltammetry (CV) and chronocoulometry (CC). In those results, redox peaks of immobilized protein were controlled via the length of chemical linkers, and it could be directly applied to the realization of bioelectronic device.

  12. The uptake of polluting chemicals into the plant and its relationship to physical-chemical substance properties

    International Nuclear Information System (INIS)

    The accumulation behaviour of 14C-labelled organic pollutants under laboratory and field conditions was investigated in spring barley and garden cress and evaluated in the light of a number of previously selected substance properties. The studies in the laboratory were restricted to one week, while those in the field were carried out over the entire growing season. They had the purpose of determining the accumulation of certain pollutants in the test plants with reference to the residues detected for those substances in the soil. The laboratory studies were focused on benzene and five chlorated derivatives as well as a further few chemicals from other groups of substances. The substances investigated in the field were benzene and an additional three chlorated benzenes. The accumulation of organic pollutants in the above-ground parts and roots of barley can rather easily be forecasted on the basis of the compounds' structural properties like molecular weight, molecule volume and connectivity indices. This applies to the majority of cases, providing the mineralisation of the substances in the soil is only minor and no unduly large amounts of metabolites are formed, the physical-chemical properties of which deviate greatly from those of the mother substances. Any such forecasts for cress should preferably be made on the basis of distribution parameters of the individual compounds. It was found that the results from laboratory and field studies were in reasonable agreement, thus permitting the same conclusions to be drawn as to the biotransfer of the test substances from the soil and the probable links between these observations and physical-chemical substance properties. (orig./MG)

  13. Biomechanical properties of acellular sciatic nerves treated with a modified chemical method

    Institute of Scientific and Technical Information of China (English)

    Xinlong Ma; Zhao Yang; Xiaolei Sun; Jianxiong Ma; Xiulan Li; Zhenzhen Yuan; Yang Zhang; Honggang Guo

    2011-01-01

    Nerve grafts are able to adapt to surrounding biomechanical environments if the nerve graft itself exhibits appropriate biomechanical properties (load, elastic modulus, etc.). The present study was designed to determine the differences in biomechanical properties between fresh and chemically acellularized sciatic nerve grafts. Two different chemical methods were used to establish acellular nerve grafts. The nerve was chemically extracted in the Sondell method with a combination of Triton X-100 (nonionic detergent) and sodium deoxycholate (anionic detergent), and in the modified method with a combination of Triton X-200 (anionic detergent), sulfobetaine-10 (SB-10, amphoteric detergents), and sulfobetaine-16 (SB-16, amphoteric detergents). Following acellularization, hematoxylin-eosin staining and scanning electron microscopy demonstrated that the effect of acellularization via the modified method was similar to the traditional Sondell method. However, effects of demyelination and nerve fiber tube integrity were superior to the traditional Sondell method. Biomechanical testing showed that peripheral nerve graft treated using the chemical method resulted in decreased biomechanical properties (ultimate load, ultimate stress, ultimate strain, and mechanical work to fracture) compared with fresh nerves, but the differences had no statistical significance (P > 0.05). These results demonstrated no significant effect on biomechanical properties of nerves treated using the chemical method. In conclusion, nerve grafts treated via the modified method removed Schwann cells, preserved neural structures, and ensured biomechanical properties of the nerve graft, which could be more appropriate for implantation studies.

  14. EVOLUTION OF PHYSICO-CHEMICAL PROPERTIES OF IODINE FORTIFIED LIPIDS

    Directory of Open Access Journals (Sweden)

    Diana Molnar

    2010-06-01

    Full Text Available in refined and deodorized sunflower oil. To investigate the influence of iodine administration in sunflower oil were evaluated the quality indices of oil (acid value, peroxide value, iodine value, refractive index, which were reported to the standard. Iodized oil manufacture and of food products fortified with iodine by additive administration in the form of iodized oil would constitute a considerable iodine supplement, which associated to iodine intake of kitchen salt, would contribute to the eradication of iodine deficiency. Incorporation ofexogenous iodine in a complex system, such as food, requires elucidation of physicochemical transformations, which may intervene in manufacturing process and storage of the product. It was established that the iodization of sunflower oil may be considered as an admissible method, which allows the incorporation of a considerableamount of iodine (0,1; 1 g/L without modifying the physicochemical properties of the product. Research of quality indices variation of iodized oil during product storage (5 weeks, demonstrated that only in the case of maximum concentration of iodine (1 g/L it was manifested a slight overcome of the maximum permitted limitcaused by the free iodine presence.

  15. Microscopic physical and chemical properties of graphite intercalation compounds

    Energy Technology Data Exchange (ETDEWEB)

    Eklund, P.C.

    1992-08-24

    Optical spectroscopy (Raman, FTIR and Reflection ) was used to study a variety of acceptor- and donor-type compounds synthesized to determine the microscopic models consistent with the spectrocsopic results. General finding is that the electrical conduction properties of these compounds can be understood on the basis that the intercalation of atomic and/or molecular species between the host graphite layers either raises or lowers the Fermi level (E{sub F)} in a graphitic band structure. This movement of E{sub F} is accomplished via a charge transfer of electrons from the intercalate layers to the graphitic layers (donor compounds), or vice versa (acceptor compounds). Furthermore, the band structure must be modified to take into account the layers of charge that occur as a result of the charge transfer. This charge layering introduces additional bands of states near E{sub F}, which are discussed. Charge-transfer also induces a perturbation of the graphitic normal mode frequencies which can be understood as the result of a contraction (acceptor compounds) or expansion (donor compounds) of the intralayer C-C bonds. Ab-initio calculations support this view and are in reasonable agreement with experimental data.

  16. Optimization of the sampling scheme for maps of physical and chemical properties estimated by kriging

    Directory of Open Access Journals (Sweden)

    Gener Tadeu Pereira

    2013-10-01

    Full Text Available The sampling scheme is essential in the investigation of the spatial variability of soil properties in Soil Science studies. The high costs of sampling schemes optimized with additional sampling points for each physical and chemical soil property, prevent their use in precision agriculture. The purpose of this study was to obtain an optimal sampling scheme for physical and chemical property sets and investigate its effect on the quality of soil sampling. Soil was sampled on a 42-ha area, with 206 geo-referenced points arranged in a regular grid spaced 50 m from each other, in a depth range of 0.00-0.20 m. In order to obtain an optimal sampling scheme for every physical and chemical property, a sample grid, a medium-scale variogram and the extended Spatial Simulated Annealing (SSA method were used to minimize kriging variance. The optimization procedure was validated by constructing maps of relative improvement comparing the sample configuration before and after the process. A greater concentration of recommended points in specific areas (NW-SE direction was observed, which also reflects a greater estimate variance at these locations. The addition of optimal samples, for specific regions, increased the accuracy up to 2 % for chemical and 1 % for physical properties. The use of a sample grid and medium-scale variogram, as previous information for the conception of additional sampling schemes, was very promising to determine the locations of these additional points for all physical and chemical soil properties, enhancing the accuracy of kriging estimates of the physical-chemical properties.

  17. Modification of optical and electrical properties of chemical bath deposited CdS using plasma treatments

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, G. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G. Alan; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2011-08-31

    Cadmium sulphide (CdS) is a well known n-type semiconductor that is widely used in solar cells. Here we report preparation and characterization of chemical bath deposited CdS thin films and modification of their optical and electrical properties using plasma treatments. CdS thin films were prepared from a chemical bath containing Cadmium chloride, Triethanolamine and Thiourea under various deposition conditions. Good quality thin films were obtained during deposition times of 5, 10 and 15 min. CdS thin films prepared for 10 min. were treated using a glow discharge plasma having nitrogen and argon carrier gases. The changes in morphology, optical and electrical properties of these plasma treated CdS thin films were analyzed in detail. The results obtained show that plasma treatment is an effective technique in modification of the optical and electrical properties of chemical bath deposited CdS thin films.

  18. The Importance of Determination of some Physical – Chemical Properties of Wheat and Flour

    Directory of Open Access Journals (Sweden)

    Husejin Keran

    2009-12-01

    Full Text Available The content of the some ingredients, such as proteins, ash, etc. is important in food products, either they are present in raw materials or in final products. As wheat is also very important food raw material, and flour as the fi nal product of milling, it is important to know their specific physical – chemical properties. The importance of knowing the physical and chemical properties of wheat and flouris due to the determination of quality and kind of fl our which is produced after milling process.In this work, some physical – chemical properties are determined and some comparations of characteristics were performed in both wheat and flour. Characteristics that were observed in this work are moisture content, ash content, protein content, Zeleny sedimentation value, gluten content and water adsorption values. On the base of results obtained in this work, some conclusions are made that could be useful for milling industry.

  19. [Relationship among soil enzyme activities, vegetation state, and soil chemical properties of coal cinder yard].

    Science.gov (United States)

    Wang, Youbao; Zhang, Li; Liu, Dengyi

    2003-01-01

    From field investigation and laboratory analysis, the relationships among soil enzyme activities, vegetation state and soil chemical properties of coal cinder yard in thermal power station were studied. The results showed that vegetation on coal cinder yard was distributed in scattered patch mainly with single species of plant, and herbs were the dominant species. At the same time, the activity of three soil enzymes had a stronger relativity to environment conditions, such as vegetation state and soil chemical properties. The sensitivity of three soil enzymes to environmental stress was in order of urease > sucrase > catalase. The relativity of three soil enzymes to environmental factor was in order of sucrase > urease > catalase. Because of urease being the most susceptible enzyme to environmental conditions, and it was marked or utmost marked interrelated with vegetation state and soil chemical properties, urease activity could be used as an indicator for the reclamation of wasteland.

  20. The structure and local chemical properties of boron-terminated tetravacancies in hexagonal boron-nitride

    OpenAIRE

    Cretu, Ovidiu; Lin, Yung-Chang; Koshino, Masanori; Tizei, Luiz H. G.; Liu, Zheng; Suenaga, Kazutomo

    2014-01-01

    Imaging and spectroscopy performed in a low-voltage scanning transmission electron microscope (LV-STEM) are used to characterize the structure and chemical properties of boron-terminated tetravacancies in hexagonal boron nitride (h-BN). We confirm earlier theoretical predictions about the structure of these defects and identify new features in the electron energy-loss spectra (EELS) of B atoms using high resolution chemical maps, highlighting differences between these areas and pristine sampl...

  1. Research and Discussion on Physical and Chemical Properties of Cultivating Substrate with Facilities

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This article, by comparing the basic concepts of substrate and soil, their composition of substance and methods of measuring the indexes of physical and chemical properties, analyzes and researches ways of choosing substrate for cultivation with facilities. It indicates that the normal physical and chemical indexes of evaluating a substrate are bulk density, total porosity, non-capillary porosity, ratio of big porosity to small porosity, the pH and the electrical conductivity (EC) value of the substrate. By...

  2. Growth and properties of few-layer graphene prepared by chemical vapor deposition

    OpenAIRE

    Park, Hye Jin; Meyer, Jannik; Roth, Siegmar; Skakalova, Viera

    2009-01-01

    The structure, and electrical, mechanical and optical properties of few-layer graphene (FLG) synthesized by chemical vapor deposition (CVD) on a Ni coated substrate were studied. Atomic resolution transmission electron microscope (TEM) images show highly crystalline single layer parts of the sample changing to multilayer domains where crystal boundaries are connected by chemical bonds. This suggests two different growth mechanisms. CVD and carbon segregation participate in the growth process ...

  3. Chemically cross-linked silk fibroin hydrogel with enhanced elastic properties, biodegradability, and biocompatibility

    OpenAIRE

    Park, Won Ho

    2016-01-01

    Min Hee Kim, Won Ho Park Department of Advanced Organic Materials and Textile Engineering System, Chungnam National University, Daejeon, Korea Abstract: In this study, the synthesis of silk fibroin (SF) hydrogel via chemical cross-linking reactions of SF due to gamma-ray (γ-ray) irradiation was investigated, as were the resultant hydrogel’s properties. Two different hydrogels were investigated: physically cross-linked SF hydrogel and chemically cross-linked SF hydrogel i...

  4. Effect of size and surrounding forest vegetation on chemical properties of soil in forest gaps

    OpenAIRE

    Özcan M; Gökbulak F

    2015-01-01

    Forest gaps have different microclimatic conditions as compared to the surrounding areas, depending on gap size and surrounding forest types and affec­ting the biological, chemical, physical, and hydrological processes in the forest openings. The objective of this study was to determine the effect of forest gap size and surrounding forest cover type (beech or mixed stands) on the soil of forest opening by analyzing several soil chemical soil properties (pH, electrical conductivity - EC, organ...

  5. Branch Structure of Corona Discharge:Experimental Simulation and Chemical Properties

    Institute of Scientific and Technical Information of China (English)

    邹吉军; 刘昌俊

    2004-01-01

    The branch structure of corona discharge has been investigated via C2H2 corona discharge. Carbon filament with excellent branch structure is formed in the discharge. This carbon filament offers a direct mimic of the branch structure of corona discharge. It providesa very useful way to study on the average energy, physical and chemical characteristics of coronadischarge. On this basis, the chemical property of corona discharge for methane conversion is discussed.

  6. Physico-chemical property prediction and environmental fate modelling of N-acylchalcogenourea derivatives

    OpenAIRE

    B Schröder; Martins, M.A.R.; Pinho, Simão; Coutinho, J. A. P.

    2013-01-01

    (Subcooled) vapour pressures, aqueous solubilities, Henry constants, log KOW and log KOC partition constants have been estimated for a set of N-acyl-chalcogenourea derivatives using several prediction methods (COSMO-RS in its COSMOtherm implementation, SPARC as well as EPA’s EPIsuite). The data are discussed in terms of substituent effects: how do subtle changes in the chemical composition influence basic physico-chemical properties and hence, the environmental fate of...

  7. A fundamental research on combustion chemical kinetic model’s precision property

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Uncertainty analysis was used to investigate the precision property of detailed chemical kinetic models.A general-purpose algorithm for assessing and evaluating the impact of uncertainties in chemical kinetic models is presented.The method was also validated through analysis of different kinetic mechanisms applied in the process of modeling NOx emission in methane flame. The algorithm,which provided a basis for further studies,was more efficient and general compared with other methods.

  8. The relationship between chemical structure and dielectric properties of plasma-enhanced chemical vapor deposited polymer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Hao [Materials Sci and Tech Applications, LLC, 409 Maple Springs Drive, Dayton OH 45458 (United States)]. E-mail: hao.jiang@wpafb.af.mil; Hong Lianggou [Materials Sci and Tech Applications, LLC, 409 Maple Springs Drive, Dayton OH 45458 (United States); Venkatasubramanian, N. [Research Institute, University of Dayton, 300 College Park, Dayton, OH 45469-0168 (United States); Grant, John T. [Research Institute, University of Dayton, 300 College Park, Dayton, OH 45469-0168 (United States); Eyink, Kurt [Air Force Research Laboratory, Materials Directorate, 3005 Hobson Way, Wright-Patterson Air Force Base, OH 45433-7707 (United States); Wiacek, Kevin [Air Force Research Laboratory, Propulsion Directorate, 1950 Fifth Street, Wright-Patterson Air Force Base, OH 45433-7251 (United States); Fries-Carr, Sandra [Air Force Research Laboratory, Propulsion Directorate, 1950 Fifth Street, Wright-Patterson Air Force Base, OH 45433-7251 (United States); Enlow, Jesse [Air Force Research Laboratory, Materials Directorate, 3005 Hobson Way, Wright-Patterson Air Force Base, OH 45433-7707 (United States); Bunning, Timothy J. [Air Force Research Laboratory, Materials Directorate, 3005 Hobson Way, Wright-Patterson Air Force Base, OH 45433-7707 (United States)

    2007-02-26

    Polymer dielectric films fabricated by plasma enhanced chemical vapor deposition (PECVD) have unique properties due to their dense crosslinked bulk structure. These spatially uniform films exhibit good adhesion to a variety of substrates, excellent chemical inertness, high thermal resistance, and are formed from an inexpensive, solvent-free, room temperature process. In this work, we studied the dielectric properties of plasma polymerized (PP) carbon-based polymer thin films prepared from two precursors, benzene and octafluorocyclobutane. Two different monomer feed locations, directly in the plasma zone or in the downstream region (DS) and two different pressures, 80 Pa (high pressure) or 6.7 Pa (low pressure), were used. The chemical structure of the PECVD films was examined by X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The dielectric constant ({epsilon} {sub r}) and dielectric loss (tan {delta}) of the films were investigated over a range of frequencies up to 1 MHz and the dielectric strength (breakdown voltage) (F {sub b}) was characterized by the current-voltage method. Spectroscopic ellipsometry was performed to determine the film thickness and refractive index. Good dielectric properties were exhibited, as PP-benzene films formed in the high pressure, DS region showed a F{sub b} of 610 V/{mu}m, an {epsilon} {sub r} of 3.07, and a tan {delta} of 7.0 x 10{sup -3} at 1 kHz. The PECVD processing pressure has a significant effect on final film structure and the film's physical density has a strong impact on dielectric breakdown strength. Also noted was that the residual oxygen content in the PP-benzene films significantly affected the frequency dependences of the dielectric constant and loss.

  9. Chemical, physical and morphometric properties of Peruvian carrot (Arracacia xanthorrhiza B.) starch.

    Science.gov (United States)

    Pérez, E E; Borneo, R; Melito, C G; Tovar, J

    1999-01-01

    Starch was isolated from Peruvian carrot (PC)--or arracacha--(Arraccacia xanthorrhiza B.) roots. Its chemical, physical, physicochemical and granular structural properties were compared to those of commercial cassava starch. Scanning electron microscopy revealed a granular size for PC starch ranging between 4 and 26 microns in diameter, with spherical and truncated-egg shapes. PC and cassava starches were similar regarding gross chemical composition and basic physical characteristics but differed in pasting properties, with PC starch showing lower breakdown and consistency indices. The two starches also showed different water absorption and solubility patterns.

  10. Effects of pig slurry application on soil physical and chemical properties and glyphosate mobility

    OpenAIRE

    2014-01-01

    Pig slurry applied to soil at different rates may affect soil properties and the mobility of chemical compounds within the soil. The purpose of this study was to evaluate the effects of rates of pig slurry application in agricultural areas on soil physical and chemical properties and on the mobility of glyphosate through the soil profile. The study was carried out in the 12th year of an experiment with pig slurry applied at rates of 0 (control), 50, 100 and 200 m³ ha-1 yr-1 on a Latossolo Ver...

  11. Distribution of Fish in the Upper Citarum River: an Adaptive Response to Physico-Chemical Properties

    OpenAIRE

    SUNARDI; KEUKEU KANIAWATI; TEGUH HUSODO; DESAK MADE MALINI; ANNISA JOVIANI ASTARI

    2012-01-01

    Distribution of fish in river is controlled by physico-chemical properties of the water which is affected by land-use complexity and intensity of human intervention. A study on fish distribution was carried out in the upper Citarum River to map the effects of physio-chemical properties on habitat use. A survey was conducted to collect fish and to measure the water quality both on dry and rainy season. The result showed that distribution of the fish, in general, represented their adaptive resp...

  12. Mechanical and Chemical Properties of Bamboo/Glass Fibers Reinforced Polyester Composites

    Directory of Open Access Journals (Sweden)

    K.Sudha Madhuri,

    2016-01-01

    Full Text Available The chemical resistance of Bamboo/Glass reinforced Polyester hybrid composites to acetic acid, Nitric acid, Hydrochloric acid, Sodium hydroxide, Sodium carbonate, Benzene, Toluene, Carbon tetrachloride and Water was studied. The tensile and impact properties of these composites were also studied. The effect of alkali treatment of bamboo fibers on these properties was studied. It was observed that the tensile and impact properties of the hybrid composites increase with glass fiber content. The author investigated the interfacial bonding between Glsss/Bamboo fiber composites by SEM. These properties found to be higher when alkali treated bamboo fibers were used in hybrid composites. The hybrid fiber composites showed better resistance to the chemicals mentioned above. The elimination of amorphous hemi-cellulose with alkali treatment leading to higher crystallinity of the bamboo fibers with alkali treatment may be responsible for these observations.

  13. STUDY ON THE PHYSICAL CHEMICAL PROPERTIES OF FFA—1 ION EXCHANGE FIBER

    Institute of Scientific and Technical Information of China (English)

    YuanSiguo; LuYun; 等

    1998-01-01

    The physical and chemical properties of FFA-1 ion exchange fiber have been characterized with IR spectrum,thermal analysis and SEM means.The pH titration curve,swelling rate,mechanical properties,resistance drop of filter layer as well as the dynamic adsorption for SO2 was determined.These experiments provided the essential parameters for the practical application of FFA-1 material in adsorption of toxic gases.

  14. Impact of Biofield Treatment on Chemical and Thermal Properties of Cellulose and Cellulose Acetate

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Cellulose being an excellent biopolymer has cemented its place firmly in many industries as a coating material, textile, composites, and biomaterial applications. In the present study, we have investigated the effect of biofield treatment on physicochemical properties of cellulose and cellulose acetate. The cellulose and cellulose acetate were exposed to biofield and further the chemical and thermal properties were investigated. X-ray diffraction study asserted that the biofield treatment did...

  15. Differences in Soil Physical and Chemical Properties of Rehabilitated and Secondary Forests

    OpenAIRE

    M. H. Akbar; Ahmed, O.H.; A. S. Jamaluddin; N. M.N.A. Majid; H. Abdul-Hamid; S. Jusop; A Hassan; K. H. Yusof; Arifin Abdu

    2010-01-01

    Problem statement: The soil properties of tropical rain forest in Southeast Asia have been characterized by several researchers; however empirical data on soil characteristics under rehabilitation program are still limited or even lacking. This research is important to determine the soil physical and chemical properties of a rehabilitated degraded forest land 19 years after planting with various indigenous species in comparison with adjacent secondary forests and to elucidate the soil fertili...

  16. International Research Project on the Effects of Chemical Ageing of Polymers on Performance Properties: Chemical and Thermal Analysis

    Science.gov (United States)

    Bulluck, J. W.; Rushing, R. A.

    1996-01-01

    Work during the past six months has included significant research in several areas aimed at further clarification of the aging and chemical failure mechanism of thermoplastics (PVDF or Tefzel) pipes. Among the areas investigated were the crystallinity changes associated with both the Coflon and Tefzel after various simulated environmental exposures using X-ray diffraction analysis. We have found that significant changes in polymer crystallinity levels occur as a function of the exposures. These crystallinity changes may have important consequences on the fracture, fatigue, tensile, and chemical resistance of the materials. We have also noted small changes in the molecular weight distribution. Again these changes may result in variations in the mechanical and chemical properties in the material. We conducted numerous analytical studies with methods including X-ray Diffraction, Gel Permeation Chromatography, Fourier Transform Infrared Spectroscopy, Ultra- Violet Scanning Analysis, GC/Mass Spectrometry, Differential Scanning Calorimetry and Thermomechanical Analysis. In the ultra-violet analysis we noted the presence of an absorption band indicative of triene formation. We investigated a number of aged samples of both Tefzel and Coflon that were forwarded from MERL. We also cast films at SWT and subjected these films to a refluxing methanol 1% ethylene diamine solution. An updated literature search was conducted using Dialog and DROLLS to identify any new papers that may have been published in the open literature since the start of this project. The updated literature search and abstracts are contained in the Appendix section of this report.

  17. Effect of chemical treatment on the thermoelectric properties of single walled carbon nanotube networks

    Energy Technology Data Exchange (ETDEWEB)

    Piao, Mingxing; Alam, Mina Rastegar; Kim, Gyutae; Dettlaff-Weglikowska, Urszula; Roth, Siegmar [School of Electrical Engineering, WCU Flexible Nano-Systems, Korea University, Seoul (Korea, Republic of)

    2012-12-15

    Carbon nanotube networks showing superior electric properties, high chemical stability, strong mechanical properties, and flexibility are also known to exhibit thermoelectric effects. However, the experimental thermoelectric figure of merit, ZT, of pristine carbon nanotubes is typically in the range of 10{sup -3}-10{sup -2}, which is still not attractive for thermal energy conversion applications. In this work, we show possible ways to improve the thermoelectric properties of single walled carbon nanotubes (SWCNTs) by means of chemical treatments. In this study, we primarily investigated the effect of chemical treatment on the electrical conductivity and thermoelectric power (TEP) of the entangled network of nanotubes, also, known as ''buckypaper''. This chemical treatment increased the electrical conductivity due to p-type doping, thereby, showing a decrease in the TEP given by the Seebeck coefficient, whereas the n-type dopants changed the sign and value of the TEP from about 40 to -40 {mu}V K{sup -1}. Neutral polymers, in terms of doping, such as PVDF, PMMA, PVA, PS, and PC, were expected to hinder phonon transport through the nanotube network, increasing the Seebeck coefficient up to ca. 50 {mu}V K{sup -1}. Our results reveal the importance of chemical doping determining the sign and the magnitude of the TEP, and role of the polymer matrix in the development of more effective thermoelectric composites based on carbon nanotubes. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Effect of chemical treatment on the thermoelectric properties of single walled carbon nanotube networks

    International Nuclear Information System (INIS)

    Carbon nanotube networks showing superior electric properties, high chemical stability, strong mechanical properties, and flexibility are also known to exhibit thermoelectric effects. However, the experimental thermoelectric figure of merit, ZT, of pristine carbon nanotubes is typically in the range of 10-3-10-2, which is still not attractive for thermal energy conversion applications. In this work, we show possible ways to improve the thermoelectric properties of single walled carbon nanotubes (SWCNTs) by means of chemical treatments. In this study, we primarily investigated the effect of chemical treatment on the electrical conductivity and thermoelectric power (TEP) of the entangled network of nanotubes, also, known as ''buckypaper''. This chemical treatment increased the electrical conductivity due to p-type doping, thereby, showing a decrease in the TEP given by the Seebeck coefficient, whereas the n-type dopants changed the sign and value of the TEP from about 40 to -40 μV K-1. Neutral polymers, in terms of doping, such as PVDF, PMMA, PVA, PS, and PC, were expected to hinder phonon transport through the nanotube network, increasing the Seebeck coefficient up to ca. 50 μV K-1. Our results reveal the importance of chemical doping determining the sign and the magnitude of the TEP, and role of the polymer matrix in the development of more effective thermoelectric composites based on carbon nanotubes. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Model Experiments on Chemical Properties of Superheavy Elements in Aqueous Solutions

    CERN Document Server

    Szeglowski, Z

    2003-01-01

    This paper presents a brief review of model experiments on investigation of chemical properties of transactinide elements, ranging from 104 to 116. The possibilities of isolation of the nuclei of these elements from nuclear reaction products, using the ion-exchange method, are also considered.

  20. Surface of Lactic Acid Bacteria: Relationships between Chemical Composition and Physicochemical Properties

    OpenAIRE

    Boonaert, C J; Rouxhet, Paul

    2000-01-01

    The surface chemical composition and physicochemical properties (hydrophobicity and zeta potential) of two lactic acid bacteria, Lactococcus lactis subsp. lactis bv. diacetilactis and Lactobacillus helveticus, have been investigated using cells harvested in exponential or stationary growth phase. The surface composition determined by X-ray photoelectron spectroscopy (XPS) was converted into a molecular composition in terms of proteins, polysaccharides, and hydrocarbonlike compounds. The conce...

  1. Physico-Chemical and Structural Properties of DeNOx and SO2 Oxidation Catalysts

    DEFF Research Database (Denmark)

    Masters, Stephen Grenville; Oehlers, Cord; Nielsen, Kurt;

    1996-01-01

    Commercial catalysts for NOx removal and SO2 oxidation and their model systems have been investigated by spectroscopic, thermal, electrochemical and X-ray methods. Structural information on the vanadium complexes and compounds as well as physico-chemical properties for catalyst model systems have...... been obtained. The results are discussed in relation to proposed reaction mechanisms....

  2. Distribution of Fish in the Upper Citarum River: an Adaptive Response to Physico-Chemical Properties

    Directory of Open Access Journals (Sweden)

    SUNARDI

    2012-12-01

    Full Text Available Distribution of fish in river is controlled by physico-chemical properties of the water which is affected by land-use complexity and intensity of human intervention. A study on fish distribution was carried out in the upper Citarum River to map the effects of physio-chemical properties on habitat use. A survey was conducted to collect fish and to measure the water quality both on dry and rainy season. The result showed that distribution of the fish, in general, represented their adaptive response to physico-chemical properties. The river environment could be grouped into two categories: (i clean and relatively unpolluted sites, which associated with high DO and water current, and (ii polluted sites characterized by low DO, high COD, BOD, water temperature, NO3, PO4, H2S, NH3, and surfactant. Fish inhabiting the first sites were Xiphophorus helleri, Punctius binotatus, Xiphophorus maculatus, and Oreochromis mossambicus. Meanwhile, the latter sites were inhabited by Liposarcus pardalis, Trichogaster trichopterus, and Poecilia reticulata. Knowledge about fish distribution in association with the pysico-chemical properties of water is crucial especially for the river management.

  3. A detailed comparative study between chemical and bioactive properties of Ganoderma lucidum from different origins

    NARCIS (Netherlands)

    Stojkovic, D.S.; Barros, L.; Calhelha, R.C.; Glamoclija, J.; Ciric, A.; Griensven, van L.J.L.D.; Sokovic, M.; Ferreira, I.C.F.R.

    2014-01-01

    A detailed comparative study on chemical and bioactive properties of wild and cultivated Ganoderma lucidum from Serbia (GS) and China (GCN) was performed. This species was chosen because of its worldwide use as medicinal mushroom. Higher amounts of sugars were found in GS, while higher amounts of or

  4. Trends in the chemical properties in early transition metal carbide surfaces: A density functional study

    DEFF Research Database (Denmark)

    Kitchin, J.R.; Nørskov, Jens Kehlet; Barteau, M.A.;

    2005-01-01

    In this paper we present density functional theory (DFT) investigations of the physical, chemical and electronic structure properties of several close-packed surfaces of early transition metal carbides, including beta-Mo2C(0 0 0 1), and the (1 1 1) surfaces of TiC, VC, NbC, and TaC. The results...

  5. Properties of alumina films by atmospheric pressure metal-organic chemical vapour deposition

    NARCIS (Netherlands)

    Haanappel, V.A.C.; Corbach, van H.D.; Fransen, T.; Gellings, P.J.

    1994-01-01

    Thin alumina films were deposited at low temperatures (290–420°C) on stainless steel, type AISI 304. The deposition process was carried out in nitrogen by metal-organic chemical vapour deposition using aluminum tri-sec-butoxide. The film properties including the protection of the underlying substrat

  6. Gas separation properties of a thermally stable and chemically resistant polytriazole membrane

    NARCIS (Netherlands)

    Gebben, B.; Mulder, M.H.V.; Smolders, C.A.

    1989-01-01

    The polymer poly (1,3-phenyl-1,4-phenyl)-4-phenyl-1,3,4-triazole has been investigated for its gas separation properties. This thermally stable and chemically resistant polymer can be processed into membranes by the phase-inversion technique because of its unexpectedly good solubility in formic acid

  7. Chemical interesterification of blends of palm stearin, coconut oil, and canola oil: physicochemical properties.

    Science.gov (United States)

    Soares, Fabiana Andreia Schäfer De Martini; da Silva, Roberta Claro; Hazzan, Márcia; Capacla, Isabele Renata; Viccola, Elise Raduan; Maruyama, Jessica Mayumi; Gioielli, Luiz Antonio

    2012-02-15

    trans-Free interesterified fat was produced for possible usage as a margarine. Palm stearin, coconut oil, and canola oil were used as substrates for chemical interesterification. The main aim of the present study was to evaluate the physicochemical properties of blends of palm stearin, coconut oil, and canola oil submitted to chemical interesterification using sodium methoxide as the catalyst. The original and interesterified blends were examined for fatty acid composition, softening and melting points, solid fat content, and consistency. Chemical interesterification reduced softening and melting points, consistency, and solid fat content. The interesterified fats showed desirable physicochemical properties for possible use as a margarine. Therefore, our result suggested that the interesterified fat without trans-fatty acids could be used as an alternative to partially hydrogenated fat.

  8. Chemical Properties of Carbon Nanotubes Prepared Using Camphoric Carbon by Thermal-CVD

    International Nuclear Information System (INIS)

    Chemical properties and surface study on the influence of starting carbon materials by using thermal chemical vapor deposition (Thermal-CVD) to produced carbon nanotubes (CNTs) is investigated. The CNTs derived from camphor were synthesized as the precursor material due to low sublimation temperature. The major parameters are also evaluated in order to obtain high-yield and high-quality CNTs. The prepared CNTs are examined using field emission scanning electron microscopy (FESEM) to determine the microstructure of nanocarbons. The FESEM investigation of the CNTs formed on the support catalysts provides evidence that camphor is suitable as a precursor material for nanotubes formation. The chemical properties of the CNTs were conducted using FTIR spectroscopy and PXRD analysis. The high-temperature graphitization process induced by the Thermal-CVD enables the hydrocarbons to act as carbon sources and changes the aromatic species into the layered graphite structure of CNTs.

  9. Chemical Properties of Carbon Nanotubes Prepared Using Camphoric Carbon by Thermal-CVD

    Science.gov (United States)

    Azira, A. A.; Rusop, M.

    2010-03-01

    Chemical properties and surface study on the influence of starting carbon materials by using thermal chemical vapor deposition (Thermal-CVD) to produced carbon nanotubes (CNTs) is investigated. The CNTs derived from camphor were synthesized as the precursor material due to low sublimation temperature. The major parameters are also evaluated in order to obtain high-yield and high-quality CNTs. The prepared CNTs are examined using field emission scanning electron microscopy (FESEM) to determine the microstructure of nanocarbons. The FESEM investigation of the CNTs formed on the support catalysts provides evidence that camphor is suitable as a precursor material for nanotubes formation. The chemical properties of the CNTs were conducted using FTIR spectroscopy and PXRD analysis. The high-temperature graphitization process induced by the Thermal-CVD enables the hydrocarbons to act as carbon sources and changes the aromatic species into the layered graphite structure of CNTs.

  10. Properties of Chemically Combusted Calcium Carbide Residue and Its Influence on Cement Properties

    OpenAIRE

    Hongfang Sun; Zishanshan Li; Jing Bai; Shazim Ali Memon; Biqin Dong; Yuan Fang; Weiting Xu; Feng Xing

    2015-01-01

    Calcium carbide residue (CCR) is a waste by-product from acetylene gas production. The main component of CCR is Ca(OH)2, which can react with siliceous materials through pozzolanic reactions, resulting in a product similar to those obtained from the cement hydration process. Thus, it is possible to use CCR as a substitute for Portland cement in concrete. In this research, we synthesized CCR and silica fume through a chemical combustion technique to produce a new reactive cementitious powder (...

  11. Properties of 15HN Steel after Various Thermo-Chemical Treatments

    Directory of Open Access Journals (Sweden)

    L. Klimek

    2007-07-01

    Full Text Available The aim of conducted research was to find universal steel that may serve to regenerate machine elements by MULTIPLEX method – or cladding of alloy steel and then subjecting to thermo-chemical treatment. This paper presents the results of metallographic examination, hardness distribution and selected tribological properties of vacuum carburized, sulphonitrided and vacuum nitrided layers obtained on 15HN steel. The results demonstrate that on 15HN steel (carburizing steel, nitrided and sulphonitrided layers show good durability and tribological properties. Therefore, it is possible to use it to regenerate machine elements by cladding method and then treat them by different thermo-chemical ways in order to obtain desired properties.

  12. The impact of the chemical synthesis on the magnetic properties of intermetallic PdFe nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Castellanos-Rubio, I.; Insausti, M.; Muro, I. Gil de [Universidad del País Vasco, UPV/EHU, Dpto. de Química Inorgánica (Spain); Arias-Duque, D. Carolina; Hernández-Garrido, Juan Carlos [Universidad de Cadiz, Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias (Spain); Rojo, T.; Lezama, L., E-mail: luis.lezama@ehu.es [Universidad del País Vasco, UPV/EHU, Dpto. de Química Inorgánica (Spain)

    2015-05-15

    Palladium-rich Iron nanoparticles in the 4–8 nm range have been produced by a combination of two methods: the thermal decomposition of organometallic precursors and the reduction of metallic salts by a polyol. Herein, it is shown how the details of the synthesis have a striking impact on the magnetic and morphological properties of the final products. In the synthesis of these bimetallic nanoparticles, the use of high reaction temperatures plays an essential role in attaining good chemical homogeneity, which has proved to have a key influence on the magnetic properties. Magnetic characterization has been performed by electron magnetic resonance and magnetization measurements, which have confirmed the superparamagnetic-like behavior at room temperature. No clear traces of magnetic polarization in palladium atoms have been detected. The combination of long-term stability and homogeneous chemical and magnetic properties makes these particles very suitable for a wide range of applications in nanotechnology.

  13. Spatial Variability of Soil Chemical Properties in the Reclaiming Marine Foreland to Yellow Sea of China

    Institute of Scientific and Technical Information of China (English)

    WEI Yi-chang; BAI You-lu; JIN Ji-yun; ZHANG Fang; ZHANG Li-ping; LIU Xiao-qiang

    2009-01-01

    Precise information about the spatial variability of soil properties is essential in developing site-specific soil management,such as variable rate application of fertilizers.In this study the sampling grid of 100 m×100 m was established to collect 1703 soil samples at the depth of 0-20 cm,and examine spatial patterns including 13 soil chemical properties (pH,OM,NH4+,PK,Ca,Mg,S,B,Cu,Fe,Mn,and Zn) in a 1760 ha rice field in Haifeng farm,China,from 6th to 22nd of April,2006,before fertilizer application and planting.Soil analysis was performed by ASI (Agro Services International) and data were analyzed both statistically and geostatistically.Results showed that the contents of soil OM,NH4+,and Zn in Haifeng farm were very low for rice production and those of others were enough to meet the need for rice cultivation.The spatial distribution model and spatial dependence level for 13 soil chemical properties varied in the field.Soil Mg and B showed strong spatial variability on both descriptive statistics and geostatistics,and other properties showed moderate spatial variability.Themaximum ranges for K,Ca,Mg,S,Cu and Mn were all~3990.6m and the minimum ranges for soil pH,OM,NH4+,P,Fe,and Zn ranged from 516.7 to 1166.2 m.Clearpatchy distribution of N,P,K,Mg,S,B,Mn,and Zn were found from their spatial distribution maps.This proved that sampling strategy for estimating variability should be adapted to the different soil chemical properties and field management.Therefore,the spatial variability of soil chemical properties with strong spatial dependence could be readily managed and a site-specific fertilization scheme for precision farming could be easily developed.

  14. Physico-chemical properties and cytotoxic effects of sugar-based surfactants: Impact of structural variations.

    Science.gov (United States)

    Lu, Biao; Vayssade, Muriel; Miao, Yong; Chagnault, Vincent; Grand, Eric; Wadouachi, Anne; Postel, Denis; Drelich, Audrey; Egles, Christophe; Pezron, Isabelle

    2016-09-01

    Surfactants derived from the biorefinery process can present interesting surface-active properties, low cytotoxicity, high biocompatibility and biodegradability. They are therefore considered as potential sustainable substitutes to currently used petroleum-based surfactants. To better understand and anticipate their performances, structure-property relationships need to be carefully investigated. For this reason, we applied a multidisciplinary approach to systematically explore the effect of subtle structural variations on both physico-chemical properties and biological effects. Four sugar-based surfactants, each with an eight carbon alkyl chain bound to a glucose or maltose head group by an amide linkage, were synthesized and evaluated together along with two commercially available standard surfactants. Physico-chemical properties including solubility, Krafft point, surface-tension lowering and critical micellar concentration (CMC) in water and biological medium were explored. Cytotoxicity evaluation by measuring proliferation index and metabolic activity against dermal fibroblasts showed that all surfactants studied may induce cell death at low concentrations (below their CMC). Results revealed significant differences in both physico-chemical properties and cytotoxic effects depending on molecule structural features, such as the position of the linkage on the sugar head-group, or the orientation of the amide linkage. Furthermore, the cytotoxic response increased with the reduction of surfactant CMC. This study underscores the relevance of a methodical and multidisciplinary approach that enables the consideration of surfactant solution properties when applied to biological materials. Overall, our results will contribute to a better understanding of the concomitant impact of surfactant structure at physico-chemical and biological levels. PMID:27137806

  15. Effects of Long-term Located Fertilization on the Physico-chemical Property of Soil Humus

    Institute of Scientific and Technical Information of China (English)

    SHI Ji-ping; ZHANG Fu-dao; LIN Bao

    2002-01-01

    A systematic study concerning the effects of a long-term stationary fertilization on content and property of soil humus in fluvo-aquic soil sampled from Malan Farm, Xinji City, Hebei, and arid red soil and paddy red soil sampled from the Institute of Red Soil, Jinxian County, Jiangxi was conducted. The results showed that long-term fertilization had effects not only on the content and composition of soil humus, but also on the physico-chemical property of humus. With applying organic manure or combined application of organic manure and chemical fertilizer, E4 and E6 values of humic acid decreased in fluvo-aquic soil and arid red soil,but increased in paddy red soil. In paddy red soil, E4 and E6 values of humic acid increased also with a single application of chemical fertilizer, but E4 and E6 values had less change of humic acid in fluvo-aquic soil and arid red soil. The effects on the visible spectroscopic property of fulvic acid were different from that of humic acid. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase E4 and E6 values of fulvic acid in three types of soil. Single application of chemical fertilizer had less effect on the E4 and E6. Long-term fertilization could also influence the ultraviolet spectroscopic property of humus. With a single application of organic manure or combined application of organic manure and chemical fertilizer, the ultraviolet absorbance of humic acid and fulvic acid increased in the three types of soil.But this effect was obvious only in short wave length, and the effect could decrease if the wave length increased. With a single application of chemical fertilizer the ultraviolet absorbance of fulvic acid could increase, but it of humic acid increased only in fluvo-aquic soil. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase the content of total acidic groups, carboxy groups and

  16. Effects of reprocessing on chemical and morphological properties of guide wires used in angioplasty

    Directory of Open Access Journals (Sweden)

    Rogério Valentim Gelamo

    2013-09-01

    Full Text Available OBJECTIVE: To investigate the influence of the reprocessing technique of enzymatic bath with ultrasonic cleaning and ethylene oxide sterilization on the chemical properties and morphological structure of polymeric coatings of guide wire for regular guiding catheter. METHODS: These techniques simulated the routine of guide wire reprocessing in many hemodynamic services in Brazil and other countries. Samples from three different manufacturers were verified by scanning electron microscopy and X-ray photoelectron spectroscopy. RESULTS: A single or double sterilization of the catheters with ethylene oxide was not associated with morphological or chemical changes. However, scanning electron microscopy images showed that the washing method was associated with rough morphological changes, including superficial holes and bubbles, in addition to chemical changes of external atomic layers of polymeric coating surfaces, as detected by the X-ray photoelectron spectroscopy method, which is compatible with extended chemical changes on catheter surfaces. CONCLUSION: The reprocessing of the catheters with ethylene oxide was not associated with morphological or chemical changes, and it seemed appropriate to maintain guide wire coating integrity. However, the method combining chemical cleaning with mechanical vibration resulted in rough anatomical and chemical surface deterioration, suggesting that this reprocessing method should be discouraged.

  17. Spatial distribution of the chemical properties of the soil and of soybean yield in the field

    Directory of Open Access Journals (Sweden)

    Alexandre Gazolla-Neto

    2016-06-01

    Full Text Available ABSTRACT The aim of this study was to evaluate the spatial dependence between chemical properties of the soil and yield components in the soybean using precision farming techniques. Samples of the soil and plants were taken from georeferenced points to determine the chemical properties of the soil and the yield components. The results were submitted to Pearson correlation analysis, descriptive statistics and geostatistics. The coefficient of variation showed a wide range of distribution for the chemical attributes of the soil, with the highest indices being found for the levels of available phosphorus (102% and potassium (72.65%. Soil pH and organic matter showed a coefficient of variation of 5.96 and 15.93% respectively. Semivariogram analysis of the yield components (productivity, 1,000-seed weight and number of seeds and the chemical properties of the soil (organic matter, pH, phosphorus, potassium, calcium, magnesium, boron, manganese and zinc fitted the spherical model with moderate spatial dependence, with values ranging from 200 to 700 m. Spatial distribution by means of map interpolation was efficient in evaluating spatial variability, allowing the identification and quantification of regions of low and high productivity in the production area, together with the distribution of soil attributes and their respective levels of availability to the soybean plants.

  18. EFFECT OF THERMAL TREATMENT ON THE CHEMICAL COMPOSITION AND MECHANICAL PROPERTIES OF BIRCH AND ASPEN

    Directory of Open Access Journals (Sweden)

    Duygu Kocaefe

    2008-05-01

    Full Text Available The high temperature treatment of wood is one of the alternatives to chemical treatment. During this process, the wood is heated to higher temperatures than those of conventional drying. The wood structure changes due to decomposition of hemicelluloses, ramification of lignin, and crystallization of cellulose. The wood becomes less hygroscopic. These changes improve the dimensional stability of wood, increase its resistance to micro-organisms, darken its color, and modify its hardness. However, wood also might loose some of its elasticity. Consequently, the heat treatment conditions have to be optimized. Therefore, it is important to understand the transformation of the chemical structure of wood caused by the treatment. In this study, the modification of the surface composition of the wood was followed with Fourier transform infrared spectroscopy (FTIR and inverse gas chromatography (IGC under different experimental conditions. The effect of maximum treatment temperatures on the chemical composition of Canadian birch and aspen as well as the correlations between their chemical transformation and different mechanical properties are presented. FTIR analysis results showed that the heat treatment affected the chemical composition of birch more compared to that of aspen. The results of IGC tests illustrated that the surfaces of the aspen and birch became more basic with heat treatment. The mechanical properties were affected by degradation of hemicellulose, ramification of lignin and cellulose crystallization.

  19. [Physico-chemical profiling of centrally acting molecules for prediction of pharmacokinetic properties].

    Science.gov (United States)

    Deák, Katalin

    2008-01-01

    Physico-chemical profiling is a fundamental tool at the early stage of drug discovery in screening drug-like candidates. Complex physico-chemical profiling, including molecular properties such as solubility, ionization, lipophilicity and permeability, has been found to be of predictive power in ADME (absorption, distribution, metabolism, elimination). In the present thesis work, the physico-chemical properties of centrally acting compounds were investigated. We determined the protonation constants (K), the partition coeffitient in octanol/water (Poct) and cyclohexane/water (Pch) systems of antidepressive sertraline and 15 antipsychotic piperidine and piperazine derivatives and calculated the delta logP (logPoct-logPch) values of the molecules. Due to the poor water solubility of the compounds potentiometry using the "co-solvent" technique was applied for the determination of the protonation constants. The logP values were measured by the dual-phase potentiometric titration in octanol/water system and the traditional shake-flask method was used in cyclohexane/water system. Highly precise physico-chemical data were obtained by these validated methods. The relationship between the structure of the molecules and the physico-chemical data was investigated. The pharmacokinetic properties of the compounds were predicted by the physico-chemical parameters. Linear relationship has been found between the brain penetration characterized by the logBB values and the delta logP values. The validity of the equation was controlled by the delta logP and the logBB values of sertraline. PMID:18986088

  20. Effects of growth altitude on chemical constituents and delayed luminescence properties in medicinal rhubarb.

    Science.gov (United States)

    Sun, Mengmeng; Li, Li; Wang, Mei; van Wijk, Eduard; He, Min; van Wijk, Roeland; Koval, Slavik; Hankemeier, Thomas; van der Greef, Jan; Wei, Shengli

    2016-09-01

    To improve the quality control of herbal drugs, there has been a major shift from evaluating individual chemicals to evaluating multiple-constituent chemicals, given the multi-pharmacology nature of herbal drugs. Therefore, rapid, systematic assays are needed in order to assess the quality of medicinal herbs using a comprehensive, integrated approach. Light-induced delayed luminescence (DL) is used to measure decaying long-term ultra-weak photon emissions following excitation with light. DL is considered to be a sensitive indicator for characterizing the properties of biological systems and herbal medicines with various therapeutic properties. The aim of this study was to examine the feasibility of using DL as a novel quality-assessment tool using rhubarb material as a model system, and to establish the correlation between DL parameters and the chemical constituents of rhubarb. Raw roots and rhizomes were collected from rhubarb (Rheum palmatum L.) at various elevations in western China. HPLC analysis was used to identify fourteen bioactive constituents. Five DL parameters were calculated from the DL decay curves of the rhubarb samples. Statistical tools, including principal component analysis, were used to classify the rhubarb samples using data obtained using two different assays. Finally, Spearman's correlation coefficient was calculated to quantify the correlation between the bioactive compounds and corresponding DL parameters. We found that both the chemical analysis and DL measurements reflect variations in the quality of rhubarb due to environment factor. The DL parameters were correlated significantly with the bioactive chemical constituents. Our results indicate that DL is a promising tool for evaluating multiple constituents and for assessing the therapeutic properties of herbal medicines. Thus, DL may be used as part of a comprehensive system for assessing the quality and/or therapeutic properties of herbal medicines. PMID:27327125

  1. The relations between Cs-137, unsupported Pb-210 and chemical properties in forest soil

    International Nuclear Information System (INIS)

    In order to research the relations between the activities of radionuclides and soil chemical properties, we measured Cs-137, unsupported Pb-210 activities and some soil chemical properties, and compared. The study site, Otyouzu basin, is mainly covered with Hinoki (Japanese cypress) stands. The 16 samples was sampled at 10m intervals with a core sampler. The concentration of Cs-137, unsupported Pb-210 in soils, and other chemical properties of soil are measured and compared each other. As chemical properties of soil, ECEC, Carbon contents (C), Fed, Feo, Fet, clay contents (clay), pH(H2O), P-t, P-org, P-ava were measured. And, from these datum, Feo/Fed, (Fed-Feo)/Fet, P-ava/P-t, C/P-org were calculated. The Correlation Coefficients (C.C.) between both radionuclide and carbon contents is relatively high. Although there were no correlations between contents of each from of phosphorus, C.C. between both radionuclide activities and C/P-org, P-ava/P-t were relatively high. It may be dew to the uneven distributions of some elements or nutrients in forest soil. So it may suggest that the concentration of Cs-137 and unsupported Pb-210 cannot be used as the indices that directly indicate the contents of some elements or nutrients except carbon contents. However, the concentration of two radionuclides may be used as indirect indices such as P-ava/P-t, C/P-org, (Fed-Feo)/Fet. These indices can give the information about chemical reactions occur in soils. (author)

  2. Chemical characterization and physico-chemical properties of aerosols at Villum Research Station, Greenland during spring 2015

    Science.gov (United States)

    Glasius, M.; Iversen, L. S.; Svendsen, S. B.; Hansen, A. M. K.; Nielsen, I. E.; Nøjgaard, J. K.; Zhang, H.; Goldstein, A. H.; Skov, H.; Massling, A.; Bilde, M.

    2015-12-01

    The effects of aerosols on the radiation balance and climate are of special concern in Arctic areas, which have experienced warming at twice the rate of the global average. As future scenarios include increased emissions of air pollution, including sulfate aerosols, from ship traffic and oil exploration in the Arctic, there is an urgent need to obtain the fundamental scientific knowledge to accurately assess the consequences of pollutants to environment and climate. In this work, we studied the chemistry of aerosols at the new Villum Research Station (81°36' N, 16°40' W) in north-east Greenland during the "inauguration campaign" in spring 2015. The chemical composition of sub-micrometer Arctic aerosols was investigated using a Soot Particle Time-of-Flight Aerosol Mass Spectrometer (SP-ToF-AMS). Aerosol samples were also collected on filters using both a high-volume sampler and a low-volume sampler equipped with a denuder for organic gases. Chemical analyses of filter samples include determination of inorganic anions and cations using ion-chromatography, and analysis of carboxylic acids and organosulfates of anthropogenic and biogenic origin using ultrahigh-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). Previous studies found that organosulfates constitute a surprisingly high fraction of organic aerosols during the Arctic Haze period in winter and spring. Investigation of organic molecular tracers provides useful information on aerosol sources and atmospheric processes. The physico-chemical properties of Arctic aerosols are also under investigation. These measurements include particle number size distribution, water activity and surface tension of aerosol samples in order to deduct information on their hygroscopicity and cloud-forming potential. The results of this study are relevant to understanding aerosol sources and processes as well as climate effects in the Arctic, especially during the Arctic haze

  3. Prediction of aged red wine aroma properties from aroma chemical composition. Partial least squares regression models.

    Science.gov (United States)

    Aznar, Margarita; López, Ricardo; Cacho, Juan; Ferreira, Vicente

    2003-04-23

    Partial least squares regression (PLSR) models able to predict some of the wine aroma nuances from its chemical composition have been developed. The aromatic sensory characteristics of 57 Spanish aged red wines were determined by 51 experts from the wine industry. The individual descriptions given by the experts were recorded, and the frequency with which a sensory term was used to define a given wine was taken as a measurement of its intensity. The aromatic chemical composition of the wines was determined by already published gas chromatography (GC)-flame ionization detector and GC-mass spectrometry methods. In the whole, 69 odorants were analyzed. Both matrixes, the sensory and chemical data, were simplified by grouping and rearranging correlated sensory terms or chemical compounds and by the exclusion of secondary aroma terms or of weak aroma chemicals. Finally, models were developed for 18 sensory terms and 27 chemicals or groups of chemicals. Satisfactory models, explaining more than 45% of the original variance, could be found for nine of the most important sensory terms (wood-vanillin-cinnamon, animal-leather-phenolic, toasted-coffee, old wood-reduction, vegetal-pepper, raisin-flowery, sweet-candy-cacao, fruity, and berry fruit). For this set of terms, the correlation coefficients between the measured and predicted Y (determined by cross-validation) ranged from 0.62 to 0.81. Models confirmed the existence of complex multivariate relationships between chemicals and odors. In general, pleasant descriptors were positively correlated to chemicals with pleasant aroma, such as vanillin, beta damascenone, or (E)-beta-methyl-gamma-octalactone, and negatively correlated to compounds showing less favorable odor properties, such as 4-ethyl and vinyl phenols, 3-(methylthio)-1-propanol, or phenylacetaldehyde.

  4. Chemical Potential Tuning and Enhancement of Thermoelectric Properties in Indium Selenides

    Directory of Open Access Journals (Sweden)

    Jong-Soo Rhyee

    2015-03-01

    Full Text Available Researchers have long been searching for the materials to enhance thermoelectric performance in terms of nano scale approach in order to realize phonon-glass-electron-crystal and quantum confinement effects. Peierls distortion can be a pathway to enhance thermoelectric figure-of-merit ZT by employing natural nano-wire-like electronic and thermal transport. The phonon-softening known as Kohn anomaly, and Peierls lattice distortion decrease phonon energy and increase phonon scattering, respectively, and, as a result, they lower thermal conductivity. The quasi-one-dimensional electrical transport from anisotropic band structure ensures high Seebeck coefficient in Indium Selenide. The routes for high ZT materials development of In4Se3−δ are discussed from quasi-one-dimensional property and electronic band structure calculation to materials synthesis, crystal growth, and their thermoelectric properties investigations. The thermoelectric properties of In4Se3−δ can be enhanced by electron doping, as suggested from the Boltzmann transport calculation. Regarding the enhancement of chemical potential, the chlorine doped In4Se3−δCl0.03 compound exhibits high ZT over a wide temperature range and shows state-of-the-art thermoelectric performance of ZT = 1.53 at 450 °C as an n-type material. It was proven that multiple elements doping can enhance chemical potential further. Here, we discuss the recent progress on the enhancement of thermoelectric properties in Indium Selenides by increasing chemical potential.

  5. SPATIAL DEPENDENCE OF ELECTRICAL CONDUCTIVITY AND CHEMICAL PROPERTIES OF THE SOIL BY ELECTROMAGNETIC INDUCTION

    Directory of Open Access Journals (Sweden)

    Flavia Cristina Machado

    2015-08-01

    Full Text Available Brazilian soils have natural high chemical variability; thus, apparent electrical conductivity (ECa can assist interpretation of crop yield variations. We aimed to select soil chemical properties with the best linear and spatial correlations to explain ECa variation in the soil using a Profiler sensor (EMP-400. The study was carried out in Sidrolândia, MS, Brazil. We analyzed the following variables: electrical conductivity - EC (2, 7, and 15 kHz, organic matter, available K, base saturation, and cation exchange capacity (CEC. Soil ECa was measured with the aid of an all-terrain vehicle, which crossed the entire area in strips spaced at 0.45 m. Soil samples were collected at the 0-20 cm depth with a total of 36 samples within about 70 ha. Classical descriptive analysis was applied to each property via SAS software, and GS+ for spatial dependence analysis. The equipment was able to simultaneously detect ECa at the different frequencies. It was also possible to establish site-specific management zones through analysis of correlation with chemical properties. We observed that CEC was the property that had the best correlation with ECa at 15 kHz.

  6. The preparation of low electroendosmosis agarose and its physico-chemical property

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Studies on Gelidium amansii agar fractionations were carried out in this paper. Gelidium amansii agar was fractionated on DEAE-Cellulose, and four fractions were obtained sequentially. The fractions were analyzed on physical and chemical properties, and IR and 13C-NMR spectroscopy applied for elucidating the chemical structure. Among the four fractions obtained, water fraction measured up to the standard of low EEO agarose. The sulfate content, ash content, electroendosmosis and gel strength(1%) of water fraction were 0.16%, 0.34%, 0.12 and 1 130g/cm2 respectively, similar to those of the Sigma products.

  7. Structure and local chemical properties of boron-terminated tetravacancies in hexagonal boron nitride.

    Science.gov (United States)

    Cretu, Ovidiu; Lin, Yung-Chang; Koshino, Masanori; Tizei, Luiz H G; Liu, Zheng; Suenaga, Kazutomo

    2015-02-20

    Imaging and spectroscopy performed in a low-voltage scanning transmission electron microscope are used to characterize the structure and chemical properties of boron-terminated tetravacancies in hexagonal boron nitride. We confirm earlier theoretical predictions about the structure of these defects and identify new features in the electron energy-loss spectra of B atoms using high resolution chemical maps, highlighting differences between these areas and pristine sample regions. We correlate our experimental data with calculations which help explain our observations. PMID:25763963

  8. The Chemical Composition and Biological Properties of Coconut (Cocos nucifera L. Water

    Directory of Open Access Journals (Sweden)

    Yan Fei Ng

    2009-12-01

    Full Text Available Coconut water (coconut liquid endosperm, with its many applications, is one of the world’s most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut water in health and medicinal applications. Coconut water is traditionally used as a growth supplement in plant tissue culture/micropropagation. The wide applications of coconut water can be justified by its unique chemical composition of sugars, vitamins, minerals, amino acids and phytohormones. This review attempts to summarise and evaluate the chemical composition and biological properties of coconut water.

  9. Effect of chemical treatment on thermal properties of fibers from pineapple

    International Nuclear Information System (INIS)

    In this work the effect of the chemical modification of natural fibres from of pineapple fibres with alkaline solution was studied. After modification the in nature and modified fibres were analyzed by XRD diffractometry and thermogravimetry with objective to evaluate influence chemical treatment in surface and in the thermal properties fibres. With the obtained results it was possible to verify an increase of 10.4 % in the crystallinity index of fibres beyond the increase around 4.5% in the degradation temperature, what it indicates an increase in the stability thermal of the fibres. (author)

  10. IR study on surface chemical properties of catalytic grown carbon nanotubes and nanofibers

    Institute of Scientific and Technical Information of China (English)

    Li-hua TENG; Tian-di TANG

    2008-01-01

    In this study, the surface chemical properties of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) grown by catalytic decomposition of methane on nickel and cobalt based catalysts were studied by DRIFT (Diffuse Reflectance Infrared Fourier Transform) and transmission Infrared (IR) spectroscopy. The results show that the surface exists not only carbon-hydrogen groups, but also carboxyl, ketene or quinone (carbonyl) oxygen-containing groups. These functional groups were formed in the process of the material growth, which result in large amount of chemical defect sites on the walls.

  11. Influence of copper nanoparticles on the physical-chemical properties of activated sludge.

    Directory of Open Access Journals (Sweden)

    Hong Chen

    Full Text Available The physical-chemical properties of activated sludge, such as flocculating ability, hydrophobicity, surface charge, settleability, dewaterability and bacteria extracellular polymer substances (EPS, play vital roles in the normal operation of wastewater treatment plants (WWTPs. The nanoparticles released from commercial products will enter WWTPs and can induce potential adverse effects on activated sludge. This paper focused on the effects of copper nanoparticles (CuNPs on these specific physical-chemical properties of activated sludge. It was found that most of these properties were unaffected by the exposure to lower CuNPs concentration (5 ppm, but different observation were made at higher CuNPs concentrations (30 and 50 ppm. At the higher CuNPs concentrations, the sludge surface charge increased and the hydrophobicity decreased, which were attributed to more Cu2+ ions released from the CuNPs. The carbohydrate content of EPS was enhanced to defense the toxicity of CuNPs. The flocculating ability was found to be deteriorated due to the increased cell surface charge, the decreased hydrophobicity, and the damaged cell membrane. The worsened flocculating ability made the sludge flocs more dispersed, which further increased the toxicity of the CuNPs by increasing the availability of the CuNPs to the bacteria present in the sludge. Further investigation indicated that the phosphorus removal efficiency decreased at higher CuNPs concentrations, which was consistent with the deteriorated physical-chemical properties of activated sludge. It seems that the physical-chemical properties can be used as an indicator for determining CuNPs toxicity to the bacteria in activated sludge. This work is important because bacteria toxicity effects to the activated sludge caused by nanoparticles may lead to the deteriorated treatment efficiency of wastewater treatment, and it is therefore necessary to find an easy way to indicate this toxicity.

  12. Effects of pig slurry application on soil physical and chemical properties and glyphosate mobility

    Directory of Open Access Journals (Sweden)

    Daniela Aparecida de Oliveira

    2014-10-01

    Full Text Available Pig slurry applied to soil at different rates may affect soil properties and the mobility of chemical compounds within the soil. The purpose of this study was to evaluate the effects of rates of pig slurry application in agricultural areas on soil physical and chemical properties and on the mobility of glyphosate through the soil profile. The study was carried out in the 12th year of an experiment with pig slurry applied at rates of 0 (control, 50, 100 and 200 m³ ha-1 yr-1 on a Latossolo Vermelho distrófico (Hapludox soil. In the control, the quantities of P and K removed by harvested grains were replaced in the next crop cycle. Soil physical properties (bulk density, porosity, texture, and saturated hydraulic conductivity and chemical properties (organic matter, pH, extractable P, and exchangeable K were measured. Soil solution samples were collected at depths of 20, 40 and 80 cm using suction lysimeters, and glyphosate concentrations were measured over a 60-day period after slurry application. Soil physical and chemical properties were little affected by the pig slurry applications, but soil pH was reduced and P levels increased in the surface layers. In turn, K levels were increased in sub-surface layers. Glyphosate concentrations tended to decrease over time but were not affected by pig slurry application. The concentrations of glyphosate found in different depths show that the pratice of this application in agricultural soils has the potential for contamination of groundwater, especially when the water table is the surface and heavy rains occur immediately after application.

  13. Physico-chemical properties of Brazilian cocoa butter and industrial blends. Part I Chemical composition, solid fat content and consistency

    Directory of Open Access Journals (Sweden)

    Ribeiro, A. P. B.

    2012-03-01

    Full Text Available A comparative study of the primary properties of six cocoa butter samples, representative of industrial blends and cocoa butter extracted from fruits cultivated in different geographical areas in Brazil is presented. The samples were evaluated according to fatty acid composition, triacylglycerol composition, regiospecific distribution, melting point, solid fat content and consistency. The results allowed for differentiating the samples according to their chemical compositions, thermal resistance properties, hardness characteristics, as well as technological adequacies and potential use in regions with tropical climates.

    En este trabajo se presenta un estudio comparativo de las propiedades primarias de mantecas de cacao, representativas de las mezclas industriales, y de la manteca de cacao original de diferentes zonas geográficas de Brasil. Las muestras fueron evaluadas de acuerdo a la composición de ácidos grasos, composición de triglicéridos, distribución de los ácidos grasos en las moléculas de triglicéridos, punto de fusión, contenido de grasa sólida y consistencia. Los resultados permitieron diferenciar las muestras por su composición química, propiedades de resistencia térmica, características de dureza, así como en materia de adecuaciones tecnológicas y los usos potenciales en las regiones de clima tropical.

  14. Optical and Structural Properties of Nanocrystalline CdS Thin Films Grown by Chemical Bath Deposition

    International Nuclear Information System (INIS)

    Nanocrystalline cadmium sulfide thin films are prepared using chemical bath deposition (CBD) technique in aqueous alkaline bath at 60 degree Celsius and their subsequent condensation on glass substrates. Effects of annealing on structural, morphological and optical properties are presented and discussed. The best annealing temperature for CBD grown CdS films is found to be 350 degree Celsius from optical properties. The optical and structural properties of CdS films are found to be sensitive to annealing temperature and are described in terms of XRD, SEM, transmission spectra and optical studies. The structural parameters such as crystallite size have been evaluated through XRD while SEM micrographs exhibit ordering of grains after annealing. The transmission spectra shift towards higher wavelength upon annealing indicating increase in crystallinity. Annealing over 350 degree Celsius is found to degrade the external structure and optical properties of the film. (author)

  15. Predicting physico-chemical properties of polychlorinated diphenyl ethers (PCDEs):potential persistent organic pollutants (POPs)

    Institute of Scientific and Technical Information of China (English)

    HUANG Jun; YU Gang; YANG Xi; ZHANG Zu-lin

    2004-01-01

    Polychlorinated diphenyl ethers(PCDEs) have received more and more concerns as a category of potentialpersistent organic pollutants( POPs). Modeling its environmental fate and exposure assessment require a number offundamental physico-chemical properties. However, the experimental data are currently limited due to the difficulty inanalysis caused by the complexity of PCDE congeners. As an alternative, the quantitative structure propertyrelationship(QSPR) approach could be used. In this paper, twelve kinds of molecular connectivity indices(MCIs) ofall 209 possible molecular structure patterns of PCDEs were calculated. Based on 106 PCDEs with three observedphysico-chemical properties-vapour pressure(PoL), aqueous solubility(Sw) and n-octanol/water(Kow) and theirMCIs data, a series of QSPR equations were established using multiple linear regression(MLR) method. As aresult, three equations with best performance were selected mainly from the view of high regression coefficient(R)and low standard error( SE). All of them showed significant relationship and high accuracy. With these equationsthe properties of other 103 patterns of PCDEs without the reported observed values were predicted. Furthermore,three partition properties for PCDE congeners-Henry' s Law constants(H), partition coefficients between gas/water(Kgw) and gas/n-octanol ( Kgo ) were calculated according to the internal relationship among these six properties.These observed and predicted values, in contrast with the criteria listed in the Stockholm treaty about POPs whichhas been signed by more than ninety countries in May 2001, illustrated that most of PCDEs congeners are potentialpersistent organic pollutants. As all descriptors/predictors are derived just from the molecular structure itself andwithout the import of any empirical parameters, this method is impersonal and promising for the estimation ofphysico-chemical properties of PCDEs.

  16. Assessment of the physico-chemical properties of phases in the Na-U-Pu-O system

    International Nuclear Information System (INIS)

    A critical review is given on the physico-chemical properties of phases in the Na-O, Na-U-O, Na-Pu-O and Na-U-Pu-O systems. This includes the phase diagrams as well as the crystallographic, mechanical, thermal, thermodynamic, transport, optical and chemical properties. This data is to be used for the modelling of the thermal, mechanical and chemical behaviour of defective LMFBR mixed oxide pins during and after reactor operation. (orig.)

  17. The influence of chemical composition on structure and mechanical properties of austenitic Cr-Ni steels

    Directory of Open Access Journals (Sweden)

    A. Kurc-Lisiecka

    2013-12-01

    Full Text Available Purpose: The aim of the paper is to investigated the influence of the chemical composition on the structure and mechanical properties of austenitic Cr-Ni steels. Special attention was put on the effect of solution heat treatment on mechanical properties of examined steels. Design/methodology/approach: The examinations of static tensile tests were conducted on ZWICK 100N5A. Hardness measurements were made by Vickers method. The X-ray analyzes were realized with the use of Dron 2.0 diffractometer equipped with the lamp of the cobalt anode. The metallographic observations were carried out on LEICA MEF 4A light microscope. Findings: Results shown that after solution heat treatment the values of strength properties (UTS, YS0.2 and hardness (HV of both investigated steels decrease and their elongation (EL increases. The X5CrNi18-8 steel in delivery state shown austenitic microstructure with twins and numerous non-metallic inclusions, while in steel X10CrNi18-8 revealed a austenitic microstructure with numerous slip bands in areas with deformation martensite α’. The examined steels after solution heat treatment followed by water-cooling has the structure of austenite. Research limitations/implications: To investigate in more detail the influence of chemical composition on structure and mechanical properties the examinations of substructure by TEM should be conducted. Originality/value: The relationship between the solution heat treatment, structure and mechanical properties of investigated steels was specified.

  18. The influence of chemical composition on the properties and structure Al-Si-Cu(Mg alloys

    Directory of Open Access Journals (Sweden)

    M. Kaczorowski

    2007-04-01

    Full Text Available The mechanical properties of different chemical composition AlSiCuMg type cast alloys after precipitation hardening are presented. The aim of the study was to find out how much the changes in chemistry of aluminum cast alloys permissible by EN-PN standards may influence the mechanical properties of these alloys. Eight AlSi5Cu3(Mg type cast alloys of different content alloying elements were selected for the study. The specimens cut form test castings were subjected to precipitation hardening heat treatment. The age hardened specimens were evaluated using tensile test, hardness measurements and impact test. Moreover, the structure investigation were carried out using either conventional light Metallography and scanning (SEM and transmission (TEM electron microscopy. The two last methods were used for fractography observations and precipitation process observations respectively. It was concluded that the changes in chemical composition which can reach even 2,5wt.% cause essential differences of the structure and mechanical properties of the alloys. As followed from quantitative evaluation and as could be predicted theoretically, copper and silicon mostly influenced the mechanical properties of AlSi5Cu3(Mg type cast alloys. Moreover it was showed that the total concentration of alloying elements accelerated and intensifies the process of decomposition of supersaturated solid solution. The increase of Cu and Mg concentration increased the density of precipitates. It increases of strength properties of the alloys which are accompanied with decreasing in ductility.

  19. Electronic absorption spectra and nonlinear optical properties of CO2 molecular aggregates: A quantum chemical study

    Indian Academy of Sciences (India)

    Tarun K Mandal; Sudipta Dutta; Swapan K Pati

    2009-09-01

    We have investigated the structural aspects of several carbon dioxide molecular aggregates and their spectroscopic and nonlinear optical properties within the quantum chemical theory framework. We find that, although the single carbon dioxide molecule prefers to be in a linear geometry, the puckering of angles occur in oligomers because of the intermolecular interactions. The resulting dipole moments reflect in the electronic excitation spectra of the molecular assemblies. The observation of significant nonlinear optical properties suggests the potential application of the dense carbon dioxide phases in opto-electronic devices.

  20. Studies on chemical bath deposited zinc sulphide thin films with special optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Ladar, Maria [Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 400028 Cluj-Napoca (Romania); ' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania); Popovici, Elisabeth-Jeanne [' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania)]. E-mail: jennypopovici@yahoo.com; Baldea, Ioan [Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 400028 Cluj-Napoca (Romania); Grecu, Rodica [' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania); Indrea, Emil [National Institute for R and D of Isotopic and Molecular Technology, Donath 71-103, 400293 Cluj-Napoca (Romania)

    2007-05-31

    Adherent and uniform zinc sulphide thin films were deposited on optical glass platelets from chemical bath containing thiourea, zinc acetate, ammonia and sodium citrate. The samples, as they were prepared were investigated by UV-vis absorption/reflection spectroscopy, fluorescence spectroscopy and X-ray diffraction. The effects of growth conditions such as reagent concentration and deposition technique (mono- and multi-layer) on optical and structural properties of the ZnS thin films have been studied. The ability of ZnS films to exhibit luminescent properties has also been investigated.

  1. Molecular design chemical structure generation from the properties of pure organic compounds

    CERN Document Server

    Horvath, AL

    1992-01-01

    This book is a systematic presentation of the methods that have been developed for the interpretation of molecular modeling to the design of new chemicals. The main feature of the compilation is the co-ordination of the various scientific disciplines required for the generation of new compounds. The five chapters deal with such areas as structure and properties of organic compounds, relationships between structure and properties, and models for structure generation. The subject is covered in sufficient depth to provide readers with the necessary background to understand the modeling

  2. The influence of chemical composition on the properties and structure Al-Si-Cu(Mg) alloys

    OpenAIRE

    M. Kaczorowski; A. Krzyńska

    2007-01-01

    The mechanical properties of different chemical composition AlSiCuMg type cast alloys after precipitation hardening are presented. The aim of the study was to find out how much the changes in chemistry of aluminum cast alloys permissible by EN-PN standards may influence the mechanical properties of these alloys. Eight AlSi5Cu3(Mg) type cast alloys of different content alloying elements were selected for the study. The specimens cut form test castings were subjected to precipitation hardening ...

  3. Thermoelectric properties of chemically substituted skutterudites YbyCo4SnxSb12-x

    International Nuclear Information System (INIS)

    We report the results of a study of thermoelectric properties of chemically substituted quasiternary materials related to the recently discovered filled skutterudite compound YbFe4Sb12. The study explored partial filling at the Yb site as well as chemical doping with Sn at the Sb site in an attempt to optimize the thermoelectric figure of merit ZT in the system YbyCo4SnxSb12-x. Our measurements of these physical quantities from room temperature down to T=10 K indicate that, in our study, only the alloy Yb0.44Co4Sb12 possessed thermoelectric properties that are improved over the parent compound YbFe4Sb12, attaining a value of ZT=0.1 at T=300 K. (c) 2000 American Institute of Physics

  4. Chemical and texture characteristics and sensory properties of “mozzarella” cheese from different feeding systems

    Directory of Open Access Journals (Sweden)

    R. Rubino

    2010-02-01

    Full Text Available The aim of this study was describing the chemical composition, the rheological characteristics and the sensory properties of “mozzarella” cheese produced with milk from buffalos fed with different diets. The study involved two farms and four feeding systems. In farm C, one group was mostly fed with Ryegrass Hay (RH and the other group with Ryegrass Silage (RS. In farm T, instead, one group was mostly fed with Corn Silage (CS and the other one with a Sorghum Silage (SS. In summer, three cheesemakings, for each farm and for each feeding system, were carried out at C.R.A. of Bella. In each farm, data were processed by the analysis of variance in order to compare the effects of two feeding systems. Some parameters of chemical and texture characteristics and sensory properties were influenced by the feeding system. Results were remarkable for the DOP products.

  5. Structural, Mechanical and Optical Properties of Plasma-chemical Si-C-N Films

    Directory of Open Access Journals (Sweden)

    A.O. Kozak

    2014-11-01

    Full Text Available An influence of the substrate temperature in the range of 40-400 °C on the properties of the Si-C-N films deposited by plasma enhanced chemical vapor deposition (PECVD technique using hexamethyldisilazane is analyzed. Study of the structure, chemical bonding, surface morphology, mechanical properties and energy gap of the obtained films was carried out using X-ray diffraction, infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, optical measurements and nanoindentation. It was established that all the films were X-ray amorphous and had low surface roughness. Intensive hydrogen effusion from the films takes place, when substrate temperature increases up to 400 °C, which promotes a decrease of roughness and an increase in hardness and Young modules more than twice.

  6. Effect of Chemicals on Geotechnical Properties of Clay Liners: A Review

    Directory of Open Access Journals (Sweden)

    Seracettin Arasan

    2010-12-01

    Full Text Available This study presents a review of recent research on the geotechnical properties (consistency limits, hydraulic conductivity, shear strength, swelling, and compressibility of clay liners conducted with organic and inorganic chemicals. Due to its low permeability, a clay liner is the main material used in solid waste disposal landfills. It is exposed there to various chemical, biological and physical events, and the clay liner is affected by the resulting leachate. The geotechnical properties of clay liners are closely related to the chemistry of the leachate. Therefore, when attempting to define the geotechnical characteristics of clay liners, the use of distilled water or tap water is far from being representative of the in-situ conditions.

  7. IMPROVEMENTS IN WOOD THERMOPLASTIC MATRIX COMPOSITE MATERIALS PROPERTIES BY PHYSICAL AND CHEMICAL TREATMENTS

    Directory of Open Access Journals (Sweden)

    Irena Zivkovic

    2016-03-01

    Full Text Available This paper presents a short overview of the developments made in the field of wood thermoplastic composites in terms of surface treatment, flammability, matrix/reinforcement model, properties and application of recycled polymer matrices. The usage of lignocellulosic fibers as reinforcement in composite materials demands well formed interface between the fiber and the matrix. Because of the different nature of reinforcement and matrix components some physical and chemical treatment methods which improve the fiber matrix adhesion were introduced, as well as the improvements of lignocellulosic fibers and thermoplastic polymer matrix based composites flammability characteristics. These physical and chemical treatments influence the hydrophilic character of the lignocellulosic fibers, and therefore change their physical and mechanical properties.

  8. Chemical and mutagenic properties of asphalt fume condensates generated under laboratory and field conditions.

    Science.gov (United States)

    Reinke, G; Swanson, M; Paustenbach, D; Beach, J

    2000-08-21

    Exposure to asphalt fumes is widely recognized as a potential occupational health concern for paving and roofing workers. Two studies suggest that asphalt fumes generated in the laboratory are carcinogenic to mice. In this study, asphalt fume condensate (AFC) was collected from the head space of an operating hot mix asphalt storage tank and from a laboratory fume-generating apparatus operating at approximately 149 degrees C and 316 degrees C. Salmonella assays for mutagenesis, in vitro chromosomal aberration assays using Chinese hamster ovary (CHO) cells, chemical analyses, and simulated distillations were performed using gas chromatography to characterize the toxicological and chemical properties of AFCs generated by these two methods. The 316 degrees C lab AFC sample was more mutagenic in the Salmonella assay than the 149 degrees C lab AFC sample, with mutagenicity indices (MIs) of 8.3 and 5.3, respectively. AFCs collected from the storage tank were not mutagenic. Chromosomal aberration assays of all AFCs were negative. Chemical analyses and simulated distillations showed substantial differences in the chemical composition of the AFC samples. The 316 degrees C lab AFC sample contained more higher-boiling-point (three- and four-ring) polycyclic aromatic sulfur heterocycle compounds than the 149 degrees C lab AFC sample, and both lab AFC samples contained 5 to 100 times more of these compounds than AFC samples collected from the asphalt storage tank. These results are consistent with other data reported in the scientific literature describing the carcinogenicity of higher-boiling-point sulfur heterocycle compounds. In contrast to other recent studies, the results of this study indicate that the chemical composition and toxicological properties of laboratory-generated asphalt fumes are not representative of those properties of fumes to which workers and the public might be exposed. PMID:10946241

  9. Physical and chemical properties of olive oil extracted from olive cultivars grown in Shiraz and Kazeroon

    DEFF Research Database (Denmark)

    Homapour, M.; Hamedi, M.; Moslehishad, M.;

    2014-01-01

    Background and objective: The composition of olive oil is significantly affected by the cultivar and climatic conditions. The present study determined the chemical characteristics of olive oil extracted from two major Iranian varieties of olive (yellow and local oil-grade) in Shiraz and Kazeroon......, two major olive-producing areas in Fars province. Materials and methods: The composition of olive oil is significantly affected by the cultivar and climatic conditions. The present study determined the chemical characteristics of olive oil extracted from two major Iranian varieties of olive (yellow...... and local oil-grade) in Shiraz and Kazeroon, two major olive-producing areas in Fars province. Results: The results showed that the physical and chemical properties of both cultivars are in accordance with national and international standards. There was a significant difference in acidity, iodine content...

  10. The physico-chemical properties of spiramycin and clarithromycin / Rodé van Eeden

    OpenAIRE

    Van Eeden, Rodé

    2012-01-01

    In most cases, organic materials exist in the solid phase as polymorphs, solvatomorphs or amorphous forms. Physico-chemical properties in the solid-state are all affected primarily in terms of dissolution, solubility, bioavailability, stability and processability. Therefore investigation into the polymorphic behaviour of APIs has become a mandatory part of drug characterisation studies by pharmaceutical companies (Giron, 2001). The influence polymorphism has on bioavailability ...

  11. Physico-chemical properties of blends of palm olein with other vegetable oils

    OpenAIRE

    Mobin Siddique, Bazlul; Ahmad, Anees; Hakimi Ibrahim, Mohamad; Hena, Sufia; Rafatullah, Mohd; Omar A. K, Mohd

    2010-01-01

    Palm oil (olein) was blended with other edible oils for the enhancement of its market acceptability in terms of melting point depression and shelf life. The physico-chemical properties like viscosity, density, melting behavior, peroxide value (PV), saponification value (SV) and iodine value (IV) of four different binary blends with four vegetable oils were evaluated. Palm olein was found to be more stable against rancidity than the other oils. For the stability against oxidation and melting p...

  12. Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal: A review

    OpenAIRE

    Glaser, B.; Lehmann, J.; Zech, W.

    2002-01-01

    Metadata only record Rapid turnover of organic matter leads to a low efficiency of organic fertilizers applied to increase and sequester C in soils of the humid tropics. Charcoal was reported to be responsible for high soil organic matter contents and soil fertility of anthropogenic soils (Terra Preta) found in central Amazonia. Therefore, we reviewed the available information about the physical and chemical properties of charcoal as affected by different combustion procedures, and the eff...

  13. Elaboration of colloidal silica sols in aqueous medium: functionalities, optical properties and chemical detection of coating

    International Nuclear Information System (INIS)

    The aim of this work was to study surface reactivity of silica nanoparticles through physical and chemical properties of sols and coatings. Applications are numerous and they are illustrated in this work by optical coating preparation for laser components and chemical gas sensor development for nitroaromatics detection. On one hand, protocol synthesis of colloidal silica sols has been developed in water medium using sol-gel process (0 to 100 w%). These sols, so-called BLUESIL, are time-stable during at least one year. Homogeneous coatings having thickness fixed to 200 nm, have been prepared on silica substrate and show high porosity and high transparence. Original films have been developed using catalytic curing in gas atmosphere (ammonia curing) conferring good abrasive resistance to the coating without significant properties modification. In order to reduce film sensitivity to molecular adsorption (water, polluting agents... ), specific BLUESIL coatings have been prepared showing hydrophobic property due to apolar species grafting onto silica nanoparticles. Using this route, coatings having several functional properties such as transparence, hydrophobicity, high porosity and good abrasive resistance have been elaborated. On the other hand, we show that colloidal silica is a material specifically adapted to the detection of nitro aromatic vapors (NAC). Indeed, the use of colloidal silica as chemical gas sensor reveals very high sensitivity, selectivity to NAC compared to Volatile Organic Compound (V.O.C) and good detection performances during one year. Moreover, chemical sensors using functionalized colloidal silica have exhibited good results of detection, even in high humidity medium (≥70 %RH). (author)

  14. Principal Chemical Properties of Artificial Soil Composed of Fly Ash and Furfural Residue

    Institute of Scientific and Technical Information of China (English)

    FENG Yong-Jun; LI Fen; WANG Xiao-Ling; LIU Xi-Min; ZHANG Lei-Na

    2006-01-01

    To solve soil shortage in reclaiming subsided land of coal mines, the principal chemical properties of artificial soil formed by mixing organic furfural residue and inorganic fly ash were examined. The results indicated that the artificial soil was suitable for agriculture use after irrigation and desalination, the available nutrients in the artificial soil could satisfy the growth demand of plants, and the pH tended to the neutrality.

  15. Soil chemical properties and maize yield under application of pig slurry biofertilizer

    OpenAIRE

    Marcelo E. Bócoli; José R. Mantovani; José M. Miranda; Douglas J. Marques; Adriano B. da Silva

    2016-01-01

    ABSTRACT Organic materials subjected to a process of anaerobic digestion in a digester produce biofertilizer that can be used in agriculture as nutrient source. The objective of this study was to evaluate the effect of pig slurry biofertilizer on soil chemical properties and on corn yield and nutrient concentrations in leaves and kernels. The experiment was conducted in the field from November 2012 to April 2013, and was arranged in a randomized block design with seven treatments and four rep...

  16. Structure and physico-chemical properties in mixed aqueoussolution of sodium alkylcarboxylate-alkyltrimethylammoniumbromide

    Institute of Scientific and Technical Information of China (English)

    HUANG, Jian-Bin(黄建滨); ZHAO, Guo-Xi(赵国玺); HE, Xu(何煦); ZHU, Bu-Yao(朱步瑶); FU, Hong-Lan(付宏兰)

    2000-01-01

    The physico-chemical properties of organized assemblies (micelle or vesicle) from sodium alkylcarboxylate-alkyltrimethyl-ammonium bromide mixture have been investigated systematically. In different mixed cationic-anionic surfactant systems, micelles and vesicles can coexist or be transformed into each other on different conditions. The experimental results are explained prelimilarily from the viewpoint of molecular packing geometry. The solubilization of organic compound in the mixed surfactant system was also studied in detail.

  17. The Importance of Determination of some Physical – Chemical Properties of Wheat and Flour

    Directory of Open Access Journals (Sweden)

    Husejin Keran

    2009-12-01

    In this work, some physical – chemical properties are determined and some comparations of characteristics were performed in both wheat and flour. Characteristics that were observed in this work are moisture content, ash content, protein content, Zeleny sedimentation value, gluten content and water adsorption values. On the base of results obtained in this work, some conclusions are made that could be useful for milling industry.

  18. Morphological and physico-chemical properties of British aquatic habitats potentially exposed to pesticides.

    OpenAIRE

    Brown, Colin D.; Turner, Nigel; Hollis, John; Bellamy, Patricia H.; Biggs, Jeremy; Williams, Penny; Arnold, Dave; Pepper, Tim; Maund, Steve

    2006-01-01

    Approaches to describe the exposure of non-target aquatic organisms to agricultural pesticides can be limited by insufficient knowledge of the environmental conditions where the compounds are used. This study analysed information from national and regional datasets gathered in the UK describing the morphological and physico-chemical properties of rivers, streams, ponds and ditches. An aggregation approach was adopted, whereby the landscape was divided into 12 hydrogeological classes for agric...

  19. Characterization of Anticancer, Antimicrobial, Antioxidant Properties and Chemical Compositions of Peperomia Pellucida Leaf Extract

    OpenAIRE

    Desy Fitrya Syamsumir; Julius Yong Fu Siong; Wendy Wee; Lee Seong Wei

    2011-01-01

    Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium) assay against human breast adenocarcinoma (MCF-7) cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then char...

  20. Effect of organic mulching on physico-chemical properties of soil

    International Nuclear Information System (INIS)

    Rice straw is used as organic mulch to regulate the hydrothermal regime of the soil. It is also used for moisture conservation, soil temperature moderation and weed suppression. Attempts were made to study the physico-chemical properties of soil through a series of experiments at four different locations of lateritic sandy loam soil of India under straw mulch. It was concluded that rice straw might be used as a nutrient source in crop production and act as mulch-cum manure. (author)

  1. Effect of different alkali treatments on the chemical composition, physical properties, and microstructure of pidan white

    OpenAIRE

    Zhang, Xianwei; Jiang, Aimin; Chen, Mingtsao; Ockerman, Herbert W.; Chen, Jiaojiao

    2013-01-01

    Changes in chemical composition, physical property and microstructure of pidan white treated with 4.5 % NaOH or 5.5 % KOH were monitored during pickling up to 4 weeks, and followed by aging for another 2 weeks. As the pickling and ageing times increased, moisture content of pidan white decreased and salt content increased for both (4.5 % NaOH and 5.5 % KOH) treatments (P 

  2. Postharvest Chemical, Sensorial and Physical-Mechanical Properties of Wild Apricot (Prunus armeniaca L.)

    OpenAIRE

    Evica MRATINIĆ; Bojan POPOVSKI; Tomo MILOŠEVIĆ; Melpomena POPOVSKA

    2011-01-01

    Some chemical, sensorial and physical-mechanical properties of 19 apricot genotypes and Hungarian Best (control) such as moisture content, soluble solids content, titratable acidity ratio and their ratio, fruit and stone mass, flesh/stone ratio, fruit dimensions (length, width, thickness), arithmetic and geometric mean diameter, sphericity, surface area and aspect ratio were determined. Their application is also discussed. The highest moisture content and stone mass observed in X-1/1/04 and X...

  3. Chemical and physical properties of poly (vinyl alcohol) hydrogel films formed by irradiation

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Chemical and physical properties of poly(vinyl alcohol)(PVA) hydrogel films were investigated as a function of production factors.The experimental results show that the gel fraction dependsstrongly on the radiation dose, the degree of swelling is inverselydependent on the concentration of PVA solution, the tensile strengthdepends mainly on the PVA blending ratio and the elongation at breakis inversely dependent on the radiation dose.

  4. Analysis of the relationship between the structure and aromatic properties of chemical compounds.

    Science.gov (United States)

    Debska, Barbara; Guzowska-Swider, Barbara

    2003-04-01

    This paper presents the results of research on the relationship between the structure and odour properties of a selection of chemical compounds. The research concerns five groups of esters, each with a different smell: almond, apricot, apple, pineapple and rose. The supposed relationship between the smell and certain selected attributes of each molecule was examined by various pattern recognition techniques using programs developed in the Department of Computer Chemistry at Rzeszów University of Technology.

  5. Physico-Chemical Properties, Antioxidant Activity and Mineral Contents of Pineapple Genotypes Grown in China

    OpenAIRE

    Xin-Hua Lu; De-Quan Sun; Qing-Song Wu; Sheng-Hui Liu; Guang-Ming Sun

    2014-01-01

    The fruit physico-chemical properties, antioxidant activity and mineral contents of 26 pineapple [Ananas comosus (L.) Merr.] genotypes grown in China were measured. The results showed great quantitative differences in the composition of these pineapple genotypes. Sucrose was the dominant sugar in all 26 genotypes, while citric acid was the principal organic acid. Potassium, calcium and magnesium were the major mineral constituents. The ascorbic acid (AsA) content ranged from 5.08 to 33.57 mg/...

  6. Effects of Sorghum Flour Addition on Chemical and Rheological Properties of Hard White Winter Wheat

    OpenAIRE

    Ranya F. Abdelghafor; Abdelmoneim I. Mustafa; Amir M.H. brahim; Yuanhong R. Chen; Padmanaban G. Krishnan

    2013-01-01

    This study was carried out to investigate the chemical and rheological properties of different blends prepared using hard white winter wheat (HWWW; Triticum aestivum Desf.) and whole or decorticated sorghum (Sorghum bicolor). Whole and decorticated sorghum were used to replace 5, 10, 15 and 20% of wheat flour. Wheat samples had higher protein, moisture and calcium values and lower fat, ash, carbohydrates, iron and phosphorous values compared to whole and decorticated sorghum flours. Decortica...

  7. Computational Nutraceutics: Chemical Reactivity Properties of the Flavonoid Naringin by Means of Conceptual DFT

    OpenAIRE

    Jorge Ignacio Martínez-Araya; Guillermo Salgado-Morán; Daniel Glossman-Mitnik

    2013-01-01

    The M06 family of density functionals has been assessed for the calculation of the molecular structure and properties of the Naringin molecule. The chemical reactivity descriptors have been calculated through Conceptual DFT. The active sites for nucleophilic and electrophilic attacks have been chosen by relating them to the Fukui function indices and the dual descriptor f(2)(r). A comparison between the descriptors calculated through vertical energy values and those arising from the Koopmans'...

  8. Effects of chemical dispersants on oil physical properties and dispersion. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Khelifa, A.; Fingas, M.; Hollebone, B.P.; Brown, C.E. [Environment Canada, Ottawa, ON (Canada). ; Pjontek, D. [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering

    2007-07-01

    Laboratory and field testing have shown that the dispersion of oil spilled in water is influenced by chemical dispersants via the modification of the interfacial properties of the oil, such as oil-brine interfacial tension (IFT). This study focused on new laboratory experiments that measured the effects on the physical properties and dispersion of oil, with particular reference to the effects of chemical dispersants on IFT and oil viscosity and the subsequent effects on oil droplet formation. Experiments were conducted at 15 degrees C using Arabian Medium, Alaska North Slope and South Louisiana crude and Corexit 9500 and Corexit 9527 chemical dispersants. The dispersants were denser than the 3 oils. The effect of IFT reduction on oil dispersion was measured and showed substantial reduction in the size and enhancement of the concentration of oil droplets in the water column. It was shown that the brine-oil IFT associated with the 3 crudes reduced to less than 3.6 mN/m with the application of the chemical dispersants, even at a low dispersant-to-oil ratio (DOR) value of 1:200. The use of chemical dispersants increased the viscosity of the dispersant-oil mixture up to 40 per cent over the neat crude oil. It was shown that for each mixing condition, an optimum value of DOR exists that provides for maximal dispersant effectiveness. The IFT reaches maximum reduction at optimum DOR. It was suggested that oil spill modelling can be improved with further study of IFT reduction with DOR and variations of critical micelle concentration with the type and solubility of chemical dispersant, oil type and oil to water ratio. 13 refs., 3 tabs., 7 figs.

  9. Machine learning predictions of molecular properties: Accurate many-body potentials and nonlocality in chemical space

    International Nuclear Information System (INIS)

    Simultaneously accurate and efficient prediction of molecular properties throughout chemical compound space is a critical ingredient toward rational compound design in chemical and pharmaceutical industries. Aiming toward this goal, we develop and apply a systematic hierarchy of efficient empirical methods to estimate atomization and total energies of molecules. These methods range from a simple sum over atoms, to addition of bond energies, to pairwise interatomic force fields, reaching to the more sophisticated machine learning approaches that are capable of describing collective interactions between many atoms or bonds. In the case of equilibrium molecular geometries, even simple pairwise force fields demonstrate prediction accuracy comparable to benchmark energies calculated using density functional theory with hybrid exchange-correlation functionals; however, accounting for the collective many-body interactions proves to be essential for approaching the 'holy grail' of chemical accuracy of 1 kcal/mol for both equilibrium and out-of-equilibrium geometries. This remarkable accuracy is achieved by a vectorized representation of molecules (so-called Bag of Bonds model) that exhibits strong nonlocality in chemical space. The same representation allows us to predict accurate electronic properties of molecules, such as their polarizability and molecular frontier orbital energies

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

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Joon; Westman, Matthew P.; Karkamkar, Abhijeet J.; Chun, Jaehun; Ronnebro, Ewa

    2015-09-01

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

  11. Heterogeneity of Physico-Chemical Properties in Structured Soils and Its Consequences

    Institute of Scientific and Technical Information of China (English)

    E. JASINSKA; H. WETZEL; T. BAUMGARTL; R. HORN

    2006-01-01

    Structured soils are characterized by the presence of inter- and intra-aggregate pore systems and aggregates, which show varying chemical, physical, and biological properties depending on the aggregate type and land use system. How far these aspects also affect the ion exchange processes and to what extent the interaction between the carbon distribution and kind of organic substances affect the internal soil strength as well as hydraulic properties like wettability are still under discussion. Thus, the objective of this research was to clarify the effect of soil aggregation on physical and chemical properties of structured soils at two scales: homogenized material and single aggregates. Data obtained by sequentially peeling off soil aggregates layers revealed gradients in the chemical composition from the aggregate surface to the aggregatecore. In aggregates from long term untreated forest soils we found lower amounts of carbon in the external layer, while in arable soils the differentiation was not pronounced. However, soil aggregates originating from these sites exhibited a higher concentration of microbial activity in the outer aggregate layer and declined towards the interior. Furthermore,soil depth and the vegetation type affected the wettability. Aggregate strength depended on water suction and differences in tillage treatments.

  12. INFLUENCE OF TORREFACTION ON SOME CHEMICAL AND ENERGY PROPERTIES OF MARITIME PINE AND PEDUNCULATE OAK

    Directory of Open Access Journals (Sweden)

    Floran Pierre

    2011-04-01

    Full Text Available This study investigated the influence of heat treatment on the chemical composition and energy properties of maritime pine (Pinus pinaster and pedunculate oak (Quercus robur. Samples were treated in a new experimental device at 220, 250, or 280 °C for 1 or 5 hours. Chemical and energy analyses were performed using standard methods. Our results clearly demonstrated an increased degradation of the material due to the combined effects of temperature and treatment duration. This mass loss was basically due to degradation of acid-soluble materials. The energy analysis showed that the fixed carbon content and higher heating value increased, for both species, whereas the volatile matter content decreased with increased extent of treatment (cumulated effects of temperature and time. In the range of temperature and duration studied here, the dimensionless energy properties for both species obeyed the same functions of overall mass loss. The relationships obtained allow quantification of the increase in wood energy concentration due to torrefaction. Mass loss is an excellent indicator of treatment extent. Analytical expressions allowing the prediction of energy and chemical properties as a function of overall mass loss, within the range of treatment extents studied here, are provided.

  13. Effect of Chemical Admixtures on the Engineering Properties of Tropical Peat Soils

    Directory of Open Access Journals (Sweden)

    Bujang B.K. Huat

    2005-01-01

    Full Text Available This research describes a study on the effect of chemical (cement and lime admixtures on the index and engineering properties (compaction and unconfined strength of tropical peat soils. The ordinary Portland cement and hydrated lime were used. The amounts cement and lime added to the peat soil sample, as a percentage of the dry soil mass was in the range of 5-15% and 5-25%, respectively. The results of the study show that the addition of the chemical admixture, cement and lime, can improve the engineering properties of tropical peat soils. The soil liquid limit is found to decrease with an increase in the cement and lime content. The soil maximum dry density is found to increase while the optimum water content is found to decrease with an increase in the cement and lime content. The unconfined compressive strength of the soil is found to increase significantly with increase in cement and lime content, especially after a long curing period. However it is also found that higher organic content of the soil negate the positive effect of the cement and lime in altering (improving the mechanical properties of the soil. When comparing the performance of the cement and lime as a chemical admixture for the tropical peat soil, the ordinary Portland cement appears to perform better than the hydrated lime.

  14. Effect of milk preacidification on low fat mozzarella cheese: II. Chemical and functional properties during storage.

    Science.gov (United States)

    Metzger, L E; Barbano, D M; Kindstedt, P S; Guo, M R

    2001-06-01

    The effect of milk preacidification on cheese manufacturing, chemical properties, and functional properties of low fat Mozzarella cheese was determined. Four vats of cheese were made in 1 d using no preacidification (control), preacidification to pH 6.0 and pH 5.8 with acetic acid, and preacidification to pH 5.8 with citric acid. This process was replicated four times. Modifications in the typical Mozzarella manufacturing procedures were necessary to accommodate milk preacidification. The chemical composition of the cheeses was similar among the treatments, except the calcium content and calcium as a percentage of protein were lower in the preacidified treatments. During refrigerated storage, the chemical and functional properties of low fat Mozzarella were affected the most by milk preacidification to pH 5.8 with citric acid. The amount of expressible serum, unmelted cheese whiteness, initial unmelted hardness, and initial apparent viscosity were lower with preacidification. The reduction in initial unmelted cheese hardness and initial apparent viscosity in the pH 5.8 citric treatments represents an improvement in the quality of low fat Mozzarella cheese that allows the cheese to have better pizza bake characteristics with shorter time of refrigerated storage. PMID:11417692

  15. Physical and Chemical Properties of Water Treatment Residue and the Characteristics of Red Pepper Growth by Using it

    OpenAIRE

    Park, Seok-Gon; Yahata, Hisashi; Kurosawa, Kiyoshi; Shin, Hyun-Tak

    2010-01-01

    Physical and chemical properties of the water treatment residue (WTR) and the WTR_, which contained compost (CP), were measured, and the effect of the properties on growth of the red pepper (Capsicum annuum‘Takanotsume’) was studied to reuse the WTR as an alternative material for decomposed granite soil (DGS). The physical properties of relative gas diffusivity (D/D_0), saturated hydraulic conductivity (K_s), water retention curve, porosity and plant-available water, and the chemical propert...

  16. Chemical precursor impact on the properties of Cu2ZnSnS4 absorber layer

    Science.gov (United States)

    Vashistha, Indu B.; Sharma, Mahesh C.; Sharma, S. K.

    2016-04-01

    In present work impact of different chemical precursor on the deposition of solar absorber layer Cu2ZnSnS4 (CZTS) were studied by Chemical Bath Deposition (CBD) method without using expensive vacuum facilities and followed by annealing. As compared to the other deposition methods, CBD method is interesting one because it is simple, reproducible, non-hazardous, cost effective and well suited for producing large-area thin films at low temperatures, although effect of precursors and concentration plays a vital role in the deposition. So, the central theme of this work is optimizing and controlling of chemical reactions for different chemical precursors. Further Effect of different chemical precursors i.e. sulphate and chloride is analyzed by structural, morphological, optical and electrical properties. The X-ray diffraction (XRD) of annealed CZTS thin film revealed that films were polycrystalline in nature with kestarite tetragonal crystal structure. The Atomic Force micrographs (AFM) images indicated total coverage compact film and as well as growth of crystals. The band gap of annealed CZTS films was found in the range of optimal band gap by absorption spectroscopy.

  17. Evaluation of Soil Physical and Chemical Properties in Poplar Plantations in North of Iran

    Directory of Open Access Journals (Sweden)

    Ali Salehi

    2012-12-01

    Full Text Available Soil physical and chemical properties and some quantitative characteristics of Populus deltoides Marsh (clone 79.51 plantations and relationships between them were evaluated in Guilan plain of north of Iran. Two same aged poplar plantations with low and high qualities were selected. In each poplar plantation, fifteen sample plots with systematic sampling method were selected. In each sample plot diameter at breast height (DBH as well as height of all trees within them was determined. Soil samples were taken from 0-20cm in each plot and soil texture, water holding capacity (WHC, bulk density (B.D and particle density (P.D as well as soil porosity, O.C, N, available P and exchangeable K were determined for each soil sample in laboratory. Tree data and soil properties between two plantations were analysed using independent samples t-test (Student’s t test at p < 0.05. The results showed that among soil physical properties, percentage of clay, sand, B.D and WHC and amongst soil chemical properties O.C, N, available P and exchangeable K were significantly different between two plantations. Heavy textured soils with high B.D are undesirable for growing of populus deltoides in study area. The results also indicated that poor quality plantations has negative effect on soil nutrient and reduces its fertility. Reduction of nutrient availability had negative effects on quantity and quality of poplar trees.

  18. Effect of Chemical Reactions on the Hydrologic Properties of Fractured and Rubbelized Glass Media

    International Nuclear Information System (INIS)

    Understanding the effect of chemical reactions on the hydrologic properties of geological media, such as porosity, permeability and dispersivity, is critical to many natural and engineered sub-surface systems. Influence of glass corrosion (precipitation and dissolution) reactions on fractured and rubbelized (crushed) forms HAN28 and LAWBP1, two candidate waste glass forms for a proposed immobilized low-activity waste (ILAW) disposal facility at the Hanford, WA site, was investigated. Flow and tracer transport experiments were conducted using fractured and rubbelized forms, before and after subjecting them to corrosion using Vapor Hydration Testing (VHT) at 200 C temperature and 200 psig pressure, causing the precipitation of alteration products. Data were analyzed using analytical expressions and CXTFIT, a transport parameter optimization code, for the estimation of the hydrologic characteristics before and after VHT. It was found that glass reactions significantly influence the hydrologic properties of ILAW glass media. Hydrologic properties of rubbelized glass decreased due to precipitation reactions, whereas those of fractured glass media increased due to reaction which led to unconfined expansion of fracture aperture. The results are unique and useful to better understand the effect of chemical reactions on the hydrologic properties of fractured and rubbelized stony media in general and glass media in particular

  19. Postharvest Chemical, Sensorial and Physical-Mechanical Properties of Wild Apricot (Prunus armeniaca L.

    Directory of Open Access Journals (Sweden)

    Evica MRATINIĆ

    2011-11-01

    Full Text Available Some chemical, sensorial and physical-mechanical properties of 19 apricot genotypes and Hungarian Best (control such as moisture content, soluble solids content, titratable acidity ratio and their ratio, fruit and stone mass, flesh/stone ratio, fruit dimensions (length, width, thickness, arithmetic and geometric mean diameter, sphericity, surface area and aspect ratio were determined. Their application is also discussed. The highest moisture content and stone mass observed in X-1/1/04 and X-1/2/04, soluble solids content in ZO-1/03, titratable acidity in ZL-2/03, SS/TA ratio in ZL-1/03, and fruit mass and flesh/stone ratio in DL-1/1/04 genotype. The most number of genotypes have orange and deep orange skin and flesh colour, respectively, whereas sweet kernel taste was predominant in most genotypes. Regarding physical-mechanical properties, the superior fruit dimensions (length, width, thickness, arithmetic and geometric mean diameter and surface area observed in DL-1/1/04 genotype, whereas the highest sphericity and surface area observed in X-1/1/04 and X-1/2/04 genotypes. Also, the series of genotypes evaluated have better chemical, sensorial and physical-mechanical properties than Hungarian Best (control. Finally, information about these properties is very important for understanding the behaviour of the product during the postharvest operations.

  20. Experimental study on the physical and chemical properties of the deep hard brittle shale

    Directory of Open Access Journals (Sweden)

    Jian Xiong

    2016-03-01

    Full Text Available In the hard brittle shale formation, rock composition, physical and chemical properties, mechanics property before and after interacting with fluid have direct relation with borehole problems, such as borehole wall collapse, mud loss, hole shrinkage. To achieve hard brittle shale micro-structure, physical–chemical properties and mechanics property, energy-dispersive X-ray diffraction (XRD, cation exchange capacity experiment and hardness test are conducted. The result of laboratory experiments indicates that, clay mineral and quartz is dominated in mineral composition. In clay mineral, illite and illite/semectite mixed layers are abundant and there is no sign of montmorillonite. Value of cation exchange capacity (CEC ranges from 102.5–330 mmol/kg and average value is 199.56 mmol/kg. High value of CEC and content of clay mineral means hard brittle shale has strong ability of hydration. The image of XRD shows well developed micro-cracks and pores, which make rock failure easily, especially when fluid invades rock inside. Shale sample soaked with anti-high temperature KCL drilling fluid on shorter immersing time has stronger strength, whereas shale sample soaked with plugging and film forming KCL drilling fluid on longer immersing time has stronger strength.

  1. Superconducting properties and chemical composition of NbTiN thin films with different thickness

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.; Peng, W.; You, L. X.; Wang, Z., E-mail: zwang@mail.sim.ac.cn [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China)

    2015-09-21

    In this research, we systematically investigated the superconducting properties and chemical composition of NbTiN thin films prepared on single-crystal MgO substrates. The NbTiN thin films with different thicknesses (4–100 nm) were deposited by reactive DC magnetron sputtering at ambient temperature. We measured and analyzed the crystal structure and thickness dependence of the chemical composition using X-ray diffraction and X-ray photoelectron spectroscopy depth profiles. The films exhibited excellent superconducting properties, with a high superconducting critical temperature of 10.1 K, low resistivity (ρ{sub 20} = 93 μΩ cm), and residual resistivity ratio of 1.12 achieved for 4-nm-thick ultrathin NbTiN films prepared at the deposition current of 2.4 A. The stoichiometry and electrical properties of the films varied gradually between the initial and upper layers. A minimum ρ{sub 20} of 78 μΩ cm and a maximum residual resistivity ratio of 1.15 were observed for 12-nm-thick films, which significantly differ from the properties of NbN films with the same NaCl structure.

  2. Evaluating effects of sewage sludge and household compost on soil physical, chemical and microbiological properties

    DEFF Research Database (Denmark)

    Debosz, K.; Petersen, S.O.; Kure, L.K.;

    2002-01-01

    Recycling of organic wastes within agriculture may help maintain soil fertility via effects on physical, chemical and biological properties. Efficient use, however, requires an individual assessment of waste products, and effects should be compared with natural variations due to climate and soil......C, as well as in the field. The following properties were monitored: wet-stability of soil aggregates, clay dispersibility, hot-water extractable carbohydrates, resin-extractable P-i, inorganic N, biomass C and N, PLFA profiles, FDA hydrolysis activity, beta-glucosidase activity and CO2 evolution. In general...... amendment on the fraction of soil in wet-stable aggregates, or on the microbiological properties tested, which supported the observation from the incubation study that effects of organic wastes were transient. (C) 2002 Elsevier Science B.V. All rights reserved....

  3. Magnetic and cytotoxic properties of hot-filament chemical vapour deposited diamond

    Energy Technology Data Exchange (ETDEWEB)

    Zanin, Hudson, E-mail: hudsonzanin@gmail.com [Faculdade de Engenharia Eletrica e Computacao, Departamento de Semicondutores, Instrumentos e Fotonica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N.400, CEP 13 083-852 Campinas, Sao Paulo (Brazil); Peterlevitz, Alfredo Carlos; Ceragioli, Helder Jose [Faculdade de Engenharia Eletrica e Computacao, Departamento de Semicondutores, Instrumentos e Fotonica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N.400, CEP 13 083-852 Campinas, Sao Paulo (Brazil); Rodrigues, Ana Amelia; Belangero, William Dias [Laboratorio de Biomateriais em Ortopedia, Faculdade de Ciencias Medicas, Universidade Estadual de Campinas, Rua Cinco de Junho 350 CEP 13083970, Campinas, Sao Paulo (Brazil); Baranauskas, Vitor [Faculdade de Engenharia Eletrica e Computacao, Departamento de Semicondutores, Instrumentos e Fotonica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N.400, CEP 13 083-852 Campinas, Sao Paulo (Brazil)

    2012-12-01

    Microcrystalline (MCD) and nanocrystalline (NCD) magnetic diamond samples were produced by hot-filament chemical vapour deposition (HFCVD) on AISI 316 substrates. Energy Dispersive X-ray Spectroscopy (EDS) measurements indicated the presence of Fe, Cr and Ni in the MCD and NCD samples, and all samples showed similar magnetisation properties. Cell viability tests were realised using Vero cells, a type of fibroblastic cell line. Polystyrene was used as a negative control for toxicity (NCT). The cells were cultured under standard cell culture conditions. The proliferation indicated that these magnetic diamond samples were not cytotoxic. - Highlights: Black-Right-Pointing-Pointer Polycrystalline diamonds doped with Fe, Cr and Ni acquire ferromagnetic properties. Black-Right-Pointing-Pointer CVD diamonds have been prepared with magnetic and semiconductor properties. Black-Right-Pointing-Pointer Micro/nanocrystalline diamonds show good cell viability with fibroblast proliferation.

  4. VARIATION OF PHYSICO-CHEMICAL PROPERTIES OF RADIATION CROSSLINKED RUBBER WITH STORAGE TIME

    Institute of Scientific and Technical Information of China (English)

    N.C. Dafader; M.E. Haque; F. Akhtar

    2005-01-01

    The effect of storage on physico-chemical properties of non-irradiated natural rubber and radiation vulcanized natural rubber (RVNR) were evaluated. The rubber films were stored under two different conditions, namely in open air and sealed polyethylene bags. The antioxidant, tris(nonylated phenyl) phosphite (TNPP) was used for preventing degradation of RVNR films. Gel content, cross-link density, tensile strength at break and 500% elongation of rubber films were measured.The results show that the retention (%) of tensile properties of rubber films with TNPP is higher than that of rubber films without antioxidants. The rubber films stored in polyethylene bags also show better retention of tensile properties than those of rubber films stored in open air.

  5. Effects of gel properties produced by chemical reactions on viscous fingering

    Science.gov (United States)

    Ujiie, Tomohiro; Nagatsu, Yuichiro; Ban, Mitsumasa; Iwata, Shuichi; Kato, Yoshihito; Tada, Yutaka

    2011-11-01

    We have experimentally investigated viscous fingering with chemical reaction producing gel. Here, two systems were employed. In one system, sodium polyacrylate (SPA) solution and ferric ion solution were used as the more and less viscous liquids, respectively. In another system, xthantan gum (XG) solution and the ferric ion solution were used as the more and less viscous liquids, respectively. For high concentration of ferric ion, viscous fingering pattern was changed into spiral pattern in the former system, whereas into fracture pattern in the latter system. We consider that the difference in the change of the patterns in the two systems will be caused by the difference in the properties of the gels. Therefore, we have measured the rheological properties of the gels by means of a rheometer. We have found that the gel in the former case is more elastic. Furthermore, we have discussed the relationship between the measured rheological properties and the observed spiral or fracturing patterns.

  6. Effects of extrusion cooking on the chemical composition and functional properties of dry common bean powders.

    Science.gov (United States)

    Ai, Yongfeng; Cichy, Karen A; Harte, Janice B; Kelly, James D; Ng, Perry K W

    2016-11-15

    The impact of extrusion cooking on the chemical composition and functional properties of bean powders from four common bean varieties was investigated. The raw bean powders were extruded under eight different conditions, and the extrudates were then dried and ground (particle size⩽0.5mm). Compared with corresponding non-extruded (raw) bean powders (particle size⩽0.5mm), the extrusion treatments did not substantially change the protein and starch contents of the bean powders and showed inconsistent effects on the sucrose, raffinose and stachyose contents. The extrusion cooking did cause complete starch gelatinization and protein denaturation of the bean powders and thus changed their pasting properties and solvent-retention capacities. The starch digestibilities of the cooked non-extruded and cooked extruded bean powders were comparable. The extruded bean powders displayed functional properties similar to those of two commercial bean powders. PMID:27283664

  7. Chemical Characteristics and Antioxidant Properties of Crude Water Soluble Polysaccharides from Four Common Edible Mushrooms

    Directory of Open Access Journals (Sweden)

    Pei-Long Sun

    2012-04-01

    Full Text Available Four crude water soluble polysaccharides, CABP, CAAP, CFVP and CLDP, were isolated from common edible mushrooms, including Agaricus bisporus, Auricularia auricula, Flammulina velutipes and Lentinus edodes, and their chemical characteristics and antioxidant properties were determined. Fourier Transform-infrared analysis showed that the four crude polysaccharides were all composed of β-glycoside linkages. The major monosaccharide compositions were D-galactose, D-glucose and D-mannose for CABP, CAAP and CLDP, while CFVP was found to consist of L-arabinose, D-galactose, D-glucose and D-mannose. The main molecular weight distributions of CABP and the other three polysaccharides were 66.0 × 104 Da, respectively. Antioxidant properties of the four polysaccharides were evaluated in in vitro systems and CABP showed the best antioxidant properties. The studied mushroom species could potentially be used in part of well-balanced diets and as a source of antioxidant compounds.

  8. Temperature dependent thermoelectric properties of chemically derived gallium zinc oxide thin films

    KAUST Repository

    Barasheed, Abeer Z.

    2013-01-01

    In this study, the temperature dependent thermoelectric properties of sol-gel prepared ZnO and 3% Ga-doped ZnO (GZO) thin films have been explored. The power factor of GZO films, as compared to ZnO, is improved by nearly 17% at high temperature. A stabilization anneal, prior to thermoelectric measurements, in a strongly reducing Ar/H2 (95/5) atmosphere at 500°C was found to effectively stabilize the chemically derived films, practically eliminating hysteresis during thermoelectric measurements. Subtle changes in the thermoelectric properties of stabilized films have been correlated to oxygen vacancies and excitonic levels that are known to exist in ZnO-based thin films. The role of Ga dopants and defects, formed upon annealing, in driving the observed complex temperature dependence of the thermoelectric properties is discussed. © The Royal Society of Chemistry 2013.

  9. Magnetic and cytotoxic properties of hot-filament chemical vapour deposited diamond

    International Nuclear Information System (INIS)

    Microcrystalline (MCD) and nanocrystalline (NCD) magnetic diamond samples were produced by hot-filament chemical vapour deposition (HFCVD) on AISI 316 substrates. Energy Dispersive X-ray Spectroscopy (EDS) measurements indicated the presence of Fe, Cr and Ni in the MCD and NCD samples, and all samples showed similar magnetisation properties. Cell viability tests were realised using Vero cells, a type of fibroblastic cell line. Polystyrene was used as a negative control for toxicity (NCT). The cells were cultured under standard cell culture conditions. The proliferation indicated that these magnetic diamond samples were not cytotoxic. - Highlights: ► Polycrystalline diamonds doped with Fe, Cr and Ni acquire ferromagnetic properties. ► CVD diamonds have been prepared with magnetic and semiconductor properties. ► Micro/nanocrystalline diamonds show good cell viability with fibroblast proliferation.

  10. Mechanical properties of chemical vapor deposited coatings for fusion reactor application

    International Nuclear Information System (INIS)

    Chemical vapor deposited coatings of TiB2, TiC and boron on graphite substrates are being developed for application as limiter materials in magnetic confinement fusion reactors. In this application severe thermal shock conditions exist and to do effective thermo-mechanical modelling of the material response it is necessary to acquire elastic moduli, fracture strength and strain to fracture data for the coatings. Four point flexure tests have been conducted from room temperature to 20000C on TiB2 and boron coated graphite with coatings in tension and compression and the mechanical properties extracted from the load-deflection data. In addition, stress relaxation tests from 500 to 11500C were performed on TiB2 and TiC coated graphite beams to assess the low levels of plastic deformation which occur in these coatings. Significant differences have been observed between the effective mechanical properties of the coatings and literature values of the bulk properties

  11. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  12. Effect of electromagnetic radiation on the physico-chemical properties of minerals

    International Nuclear Information System (INIS)

    The electromagnetic radiation effect represented by gamma rays was investigated through; chemical analysis, X-ray diffraction (XRD), scanning electron microscopy (Sem) and magnetization when applied at a dose of 0.5704 Gy (0.5704 J/ kg) at a feed relation of 18.40 ± 1.13 mGy/ h., in different minerals; in order to characterize the impact of the same from 137Cs in the physicochemical properties of these minerals. All the irradiated samples showed chemical stability at this stage undetectable other both in the XRD study and in the images analysis obtained by Sem; and at present almost the same chemical composition as the non-irradiated samples. So the same patterns of X-ray diffraction thereof, show a tendency to slightly lower the intensity of the most representative peaks of each mineral phase, which may be due to a decrease in crystallinity or preferential crystallographic orientation in crystals. In the micrographs analysis obtained by Sem on the irradiated samples, some holes (open pores) present in the particles were observed, mainly chalcopyrite and sphalerite lesser extent, seen this fact may be due to Compton Effect, in the radiation process. In relation to the magnetization property, a variation is obtained in the saturation magnetization (Ms) for the irradiated samples containing iron and more significantly in the chalcopyrite case. Therefore, with the radiation level used; slight changes occurring in the physical properties of minerals, whereas they remained stable chemically. These small changes may represent a signal that electromagnetic radiation applied at higher doses, is a viable option for improving the mineral processing. (author)

  13. Chemical and physical properties of Amazon forest soils in relation to their genesis

    Directory of Open Access Journals (Sweden)

    C. A. Quesada

    2009-04-01

    Full Text Available Soil samples were collected in six South American countries in a total of 71 different 1 ha forest plots across the Amazon Basin as part of the RAINFOR project. They were analysed for total and exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality proposed. A diverse range of soils was found. For the western areas near the Andean cordillera and the southern and northern fringes, soils tend to be distributed among the lower pedogenetic levels, while the central and eastern areas of Amazonia have more intensely weathered soils. This gives rise to a large variation of soil chemical and physical properties across the Basin, with soil properties varying predictably along a gradient of pedogenic development. Nutrient pools generally increased slightly in concentration from the youngest to the intermediate aged soils after which a gradual decline was observed with the lowest values found in the most weathered soils. Soil physical properties were strongly correlated with soil fertility, with favourable physical properties occurring in highly weathered and nutrient depleted soils and with the least weathered, more fertile soils having higher incidence of limiting physical properties. Soil phosphorus concentrations varied markedly in accordance with weathering extent and appear to exert an important influence on the nitrogen cycle of Amazon forest soils.

  14. [Nitrilotriacetic acid (NTA)--properties, distribution and behavior in the environment. I. Chemical and toxicological properties of NTA].

    Science.gov (United States)

    Jedra, M; Malanowska, M

    1995-01-01

    The reason of the interest shown in the properties of NTA is the possibility of its use for the replacement of polyphosphates in washing powders which are the cause of water eutrophization. In the light of literature data the chemical properties of NTA and the conditions influencing the course of the reaction of complex formation with metal ions in aqueous solutions are discussed Equilibrium constants of these reactions are presented, with diagrams obtained in computer assisted analysis of the conditions of equilibrium of NTA reaction with metal ions in the solutions occurring in physiological conditions and in the environment. On the basis of the opinions of expert committees the toxicity of NTA for mammalian organisms are described. It has been shown that NTA has no teratogenic or mutagenic action, however, in 2-year observations of mice and rats the intake of NTA produced lesions of uroepithelium with development of tumours. This effect of NTA has been demonstrated to be closely connected with its property of complex formation with metal ions. Experiments are described in which confirmation was obtained of the hypothesis that pathological lesions of renal tabules are caused by accumulation of zinc and bladder tumours are caused by binding by NTA of calcium from epithelial cells.

  15. Effect of grinding on chemical and physical properties of rice husk ash

    Institute of Scientific and Technical Information of China (English)

    Sumrerng Rukzon; Prinya Chindaprasirt; Rattana Mahachai

    2009-01-01

    The effect of grinding on the chemical and physical properties of rice husk ash was studied.Four rice husk ashes with dif-ferent finenesses, i.e.coarse original rice husk ash (RHA0), RHAI, RHA2, and RHA3 were used for the study.Ordinary Portland cement (OPC) was partially replaced with rice husk ash at 20% by weight of binder.The water to binder ratio (W/B) of the mortar was maintained at 110%±5% with flow table test.Specific gravity, fineness, chemical properties, compressive strength, and porosity test of mortars were determined.The differences in chemical composition of the rice husk ashes with different finenesses from the same batch are small.The use of RHA3 produces the mortars with good strength and low porosity.The strength of the mortar im-proves with partial replacement of RHA3 in comparison with normal coarse rice husk ash.The use of RHA3 results in a strong anddense mortar, which is due to the better dispersion and filling effect, as well as an increase in the pozzolanic reaction.

  16. Effect of chemical treatment of Kevlar fibers on mechanical interfacial properties of composites.

    Science.gov (United States)

    Park, Soo-Jin; Seo, Min-Kang; Ma, Tae-Jun; Lee, Douk-Rae

    2002-08-01

    In this work, the effects of chemical treatment on Kevlar 29 fibers have been studied in a composite system. The surface characteristics of Kevlar 29 fibers were characterized by pH, acid-base value, X-ray photoelectron spectroscopy (XPS), and FT-IR. The mechanical interfacial properties of the final composites were studied by interlaminar shear strength (ILSS), critical stress intensity factor (K(IC)), and specific fracture energy (G(IC)). Also, impact properties of the composites were investigated in the context of differentiating between initiation and propagation energies and ductile index (DI) along with maximum force and total energy. As a result, it was found that chemical treatment with phosphoric acid solution significantly affected the degree of adhesion at interfaces between fibers and resin matrix, resulting in improved mechanical interfacial strength in the composites. This was probably due to the presence of chemical polar groups on Kevlar surfaces, leading to an increment of interfacial binding force between fibers and matrix in a composite system.

  17. Microstructures and Mechanical Properties of Laser Welding Joint of a CLAM Steel with Revised Chemical Compositions

    Science.gov (United States)

    Chen, Shuhai; Huang, Jihua; Lu, Qi; Zhao, Xingke

    2016-05-01

    To suppress the tendency to form delta ferrite in weld metal (WM) of China low activation martensitic (CLAM) steel joint, a CLAM steel with revised chemical compositions was designed. Laser welding of the CLAM steel was investigated. The microstructures of the WM and heat-affected zone were analyzed. The impact toughness of the WM was evaluated by a Charpy impact test method with three V notches. The influence of temper temperature on mechanical properties was analyzed. It was found that the delta ferrite was eliminated almost completely in laser WM of CLAM steel with revised chemical compositions which has lower tendency to form delta ferrite than original chemical compositions. The joint has higher tensile strength than the parent metal. With increasing the heat input, the impact toughness of the joint is approximatively equal with that of parent metal first and then decreases obviously. Temper treatment could effectively improve mechanical property of the joint. When the temper temperature exceeds 600 °C, the impact toughness of the joint is higher than that of the parent metal.

  18. Shelf life of anchovy products (Engraulis encrasicolus: evaluation of sensory, microbiological and chemical properties

    Directory of Open Access Journals (Sweden)

    Andrea Ariano

    2014-02-01

    Full Text Available Fishery products have always been an important food in Italy. In the past, increased consumption was mainly due to the good quality of the products, easiness of use and their beneficial effects on health. Recently, owing to the national financial crisis, there has been a decline in the consumption of fish. In fact, in 2013, according to data from ISMEA, the consumption of fresh fish suffered a sharp contraction (-5%. This decline also concerns anchovy (Engraulis encrasicolus. This species, partly because of its low price, is a mainstay of traditional Italian food. The aim of this study was to evaluate sensorial, chemical and microbiological properties of anchovy-based (Engraulis encrasicolus products during storage at 4 and -20°C. Fresh anchovies, obtained from the wholesale fish market of Pozzuoli (Southern Italy were cut into small pieces and hand-prepared using bread, eggs, cheese and lemon juice. Samples were analysed after 0, 2, 4, 6 and 8 days of storage at 4°C. An aliquot was quickly frozen and analysed after 34 days at -20°C. Sensory assessment, microbiological (specific spoilage organisms, Listeria spp. and Salmonella spp. and chemical (histamine, total volatile basic nitrogen, trimethylamine, thiobarbituric acid, pH and aw analyses were performed. Results showed that the shelf life of anchovy products was less than 5 days for the samples stored at 4°C. At -20°C, all anchovies preparations showed good sensory, microbiological and chemical properties for 34 days.

  19. Effect of slope position on physico-chemical properties of eroded soil

    Directory of Open Access Journals (Sweden)

    Farmanullah Khan, Zubair Hayat, Waqar Ahmad,

    2013-05-01

    Full Text Available The research work was conducted on eroded soil (Missa Series in Samarbagh, District Lower Dir to determine the effect of slope position on soil physico-chemical properties. Soil samples were collected from top-slope, mid-slope and bottom slope positions at horizon-A, B and C. Results showed a significant difference among the physico-chemical properties of top, mid and bottom slope soils. Bulk density of the top-slope (1.51 g cm-3 was the highest followed by mid (1.39 g cm-3 and bottom slopes (1.32 g cm-3. Conversely, electrical conductivity EC-2.47 dS m-1, phosphorus (3.40 mg kg-1, Potassium (118.8 mg kg-1, Organic matter content (1.52 %, clay content (20.39 % and silt content (49.17% were the highest at bottom slope followed by mid and top-slopes, respectively. Soil A, B and C horizons were also significantly (p<0.05 different in their physico-chemical properties. Mean values showed that horizon Ap had the highest bulk density (1.43 g cm-3 and lower electrical conductivity (1.74 dS m-1, phosphorus (2.29 mg kg-1, potassium (84.86 mg kg-1, organic matter (1.08%, clay (12.83% and silt content (40.49% than both the B and C horizons. The deterioration in physico-chemical properties of top slope as compared to mid and bottom slopes and that of Ap horizon as compared to B and C horizons were presumed to be due to past soil erosion effect that removed the finer soil particles including soil organic matter and other plant nutrients. This study concluded that increasing extent of erosion due to slope effect can further deteriorate soil properties. The control of such damaging effects would require soil conservation strategies such as proper land levelling, afforestation, terracing and inclusion of restorative crops in cropping systems on these lands.

  20. Studies on chemical charge doping related optical properties in monolayer WS2

    Science.gov (United States)

    Rivera, Adriana M.; Gaur, Anand P. S.; Sahoo, Satyaprakash; Katiyar, Ram S.

    2016-09-01

    Thermal stability of quasi particles, i.e., exciton and trion, and a strong particle-particle interaction significantly tune the optical properties of atomically thin two dimensional (2D) metal dichalcogenides. The present work addresses the effect of inherent defects upon optical properties of chemical vapor deposition grown 1 L-WS2 and proposes the use of chemical transfer doping as a reversible and simple method for identification of the type of excess charge in the system. Photoluminescence (PL) studies in pristine 1 L-WS2 show that an additional band at ˜0.06 eV below trion (X±) PL band was evolved (at low temperature) which was associated to the bound exciton with charged/neutral defect. Using 7,7,8,8-Tetracyanoquinodimethane and 2,2-bis1,3-dithiolylidene as p and n-type dopants, respectively, we determined that the inherent defects/metal vacancies, which could be due to the presence of Tungsten metal deficiency, contributed in p-type nature of the pristine 1 L-WS2. Doping of 2D transition metal dichalcogenides materials with organic molecule via the surface charge transfer method is not only a way to provide a handy way to tailor the electronic and optical properties but also can be used as a tool to determine the nature of defects in the material.

  1. Physico-chemical properties and toxicity of alkylated polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Kang, Hyun-Joong; Lee, So-Young; Kwon, Jung-Hwan

    2016-07-15

    Crude oil and refined petroleum products contain many polycyclic and heterocyclic aromatic hydrocarbons, in particular, alkylated PAHs. Although alkylated PAHs are found in significantly higher quantities than their corresponding unsubstituted PAHs, the most studies on the physico-chemical properties and toxicities of these compounds have been conducted on unsubstituted PAHs. In this study, we measured crucial physico-chemical properties (i.e., water solubility, partition coefficients between polydimethylsiloxane and water (KPDMSw), and partition coefficient between liposomes and water (Klipw)) of selected alkylated PAHs, and evaluated their toxicity using the luminescence inhibition of Aliivibrio fischeri and growth inhibition of Raphidocelis subcapitata. In general, the logarithms of these properties for alkylated PAHs showed good linear correlations with log Kow, as did those for unsubstituted PAHs. Changes in molecular symmetry on the introduction of alkyl groups on aromatic ring structure significantly altered water solubility. The inhibition of bacterial luminescence and algal growth by alkylated PAHs can be explained well by the baseline toxicity hypothesis, and good linear relationships between log Kow or log Klipw and log (1/EC50) were found.

  2. Structural, optical and electrical properties of chemically derived nickel substituted zinc ferrite nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarty, S. [Department of Physics, The University of Burdwan, Burdwan 713 104 (India); Pal, M., E-mail: palm@cgcri.res.in [CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Dutta, A., E-mail: adutta@phys.buruniv.ac.in [Department of Physics, The University of Burdwan, Burdwan 713 104 (India)

    2015-03-01

    Single phase spinel Ni substituted nanocrystalline Zn ferrites have been synthesized using a soft chemical route. Effect of Ni substitution on structure, electrical and optical properties has been investigated. X-ray diffraction study confirms the growth of single phase nanocrystalline Ni substituted Zn ferrites. FTIR and UV–Visible studies delineate the change in structure and optical band gap due to inclusion of Ni ions. Substitution of Ni ion has been manifested on lattice parameter which systematically decreases from 8.448 Å to 8.280 Å. An initial increase followed by subsequent decrease in optical band gap with the increase in Ni content is observed. In addition, both ac and dc electrical studies shows anomalous behavior in conductivity and dielectric properties for the samples having Ni content in the range 0.2–0.6 mol fraction which can be attributed to the normal to inverse spinel structural changes. - Highlights: • Pure single phase nanocrystalline Zn/Ni ferrites by facile soft chemical route. • Changes in microstructural parameters of Zn ferrite is observed due to Ni inclusion. • Optical band gap shows a maximum while the concentration of Ni increases. • Inverse to spinal ferrite change is observed in ac and dc electrical properties.

  3. Antioxidant and chemical properties of essential oil extracted from blend of selected spices

    Directory of Open Access Journals (Sweden)

    Ochuko Lucky Erukainure

    2015-07-01

    Full Text Available Objective: To investigate the chemical properties of essential oil extracted from blends of selected Nigerian spices as well as its antioxidant protective potentials against free radical in vitro. Methods: Essential oil was extracted from selected spices blend consisting of Monodora myristica, Myristica fragrans, Tetrapleura tetraptera, and Aframomum sceptrum using a Clevenger type apparatus. Oil obtained was subjected to phytochemical and gas chromatography-mass spectrometer analysis as well as analyzed for antioxidant activity which covers for 1,1-diphenyl-2 picrylhydrazyl, nitric oxide scavenging activities and reducing property. Results: Gas chromatography-mass spectrometer analysis revealed over 50 compoundfs with α-phellandrene being the most predominant compound (27.32%, which was followed by (--β-bourbonene (15.78% and 5-(1-methylethyl-α-phellandrene (11.80%. Phytochemical analysis showed high flavonoid content and a lower phenolic content. The oil showed a dose like dependent effect on the1-diphenyl-2 picrylhydrazyl and nitric oxide scavenging activities, these activities increased with increasing concentration. The same was also observed for the reducing power properties of the oil. Conclusions: The antioxidant activities exhibited by the essential oil in vitro signify its protective potential against free radicals. The chemical constituents, α-phellandrene in particular and the studied phytochemicals may be responsible for these effects. However, in vivo study is needed to further authenticate this potency.

  4. Evolution of mechanical properties of silicate glasses: Impact of the chemical composition and effects of irradiation

    International Nuclear Information System (INIS)

    This thesis examines: (1) how the chemical composition changes the hardness, toughness, and stress corrosion cracking behavior in model pristine and (2) how external irradiation impact these properties. It is to be incorporated in the context of the storage of nuclear waste in borosilicate glass matrix, the structural integrity of which should be assessed. Eight simplified borosilicate glasses made of 3 oxides with modulated proportions (SiO2-B2O3-Na2O (SBN) have been selected and their hardness, toughness, and stress corrosion cracking behavior have been characterized prior and after irradiation. The comparative study of the non-irradiated SBN glasses provides the role played by the chemical composition. The sodium content is found to be the key parameter: As it increases, the glass plasticity increases, leading to changes in the mechanical response to strain. Hardness (Hv) and toughness (Kc) decrease since the flow under indenter increases. The analysis of the stress corrosion behavior evidences a clear shift of the SCC curves linked also to the glass plasticity. Four of the 8 simplified SBN glass systems highlight the influence of electron, light and heavy ions irradiations on the mechanical properties. Once again, the sodium content is a key parameter. It is found to inhibit the glass modification: Glasses with high sodium content are more stable. Ions irradiations highlight the predominant role of nuclear interaction in changing the glass properties. Finally, electronic interaction induced by helium and electron irradiation does not lead to the same structural/mechanical glasses variations. (author)

  5. Antioxidant and chemical properties of essential oil extracted from blend of selected spices

    Institute of Scientific and Technical Information of China (English)

    Ochuko Lucky Erukainure; Funmi Olabisi Kayode; Olubanke Adetutu Adeyoju; Sunday Oluwaseun Adenekan; Godfrey Asieba; Atinuke Ajayi; Mosebolatan Victoria Adegbola; Bolanle Basirat Sarumi

    2015-01-01

    Objective:To investigate the chemical properties of essential oil extracted from blends of selected Nigerian spices as well as its antioxidant protective potentials against free radicalin vitro. Methods: Essential oil was extracted from selected spices blend consisting ofMonodora myristica, Myristica fragrans, Tetrapleura tetraptera, andAframomum sceptrum using a Clevenger type apparatus. Oil obtained was subjected to phytochemical and gas chromatography-mass spectrometer analysis as well as analyzed for antioxidant activity which covers for 1,1-diphenyl-2 picrylhydrazyl, nitric oxide scavenging activities and reducing property. Results: Gas chromatography-mass spectrometer analysis revealed over 50 compoundfs withα-phellandrene being the most predominant compound (27.32%), which was followed by (-)-β-bourbonene (15.78%) and 5-(1-methylethyl)-α-phellandrene (11.80%). Phytochemical analysis showed high flavonoid content and a lower phenolic content. The oil showed a dose like dependent effect on the1-diphenyl-2 picrylhydrazyl and nitric oxide scavenging activities, these activities increased with increasing concentration. The same was also observed for the reducing power properties of the oil. Conclusions: The antioxidant activities exhibited by the essential oilin vitro signify its protective potential against free radicals. The chemical constituents,α-phellandrene in particular and the studied phytochemicals may be responsible for these effects. However,in vivo study is needed to further authenticate this potency.

  6. Physico-chemical properties and toxicity of alkylated polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Kang, Hyun-Joong; Lee, So-Young; Kwon, Jung-Hwan

    2016-07-15

    Crude oil and refined petroleum products contain many polycyclic and heterocyclic aromatic hydrocarbons, in particular, alkylated PAHs. Although alkylated PAHs are found in significantly higher quantities than their corresponding unsubstituted PAHs, the most studies on the physico-chemical properties and toxicities of these compounds have been conducted on unsubstituted PAHs. In this study, we measured crucial physico-chemical properties (i.e., water solubility, partition coefficients between polydimethylsiloxane and water (KPDMSw), and partition coefficient between liposomes and water (Klipw)) of selected alkylated PAHs, and evaluated their toxicity using the luminescence inhibition of Aliivibrio fischeri and growth inhibition of Raphidocelis subcapitata. In general, the logarithms of these properties for alkylated PAHs showed good linear correlations with log Kow, as did those for unsubstituted PAHs. Changes in molecular symmetry on the introduction of alkyl groups on aromatic ring structure significantly altered water solubility. The inhibition of bacterial luminescence and algal growth by alkylated PAHs can be explained well by the baseline toxicity hypothesis, and good linear relationships between log Kow or log Klipw and log (1/EC50) were found. PMID:27037474

  7. Research Update: Mechanical properties of metal-organic frameworks – Influence of structure and chemical bonding

    Directory of Open Access Journals (Sweden)

    Wei Li

    2014-12-01

    Full Text Available Metal-organic frameworks (MOFs, a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

  8. The Effect of Sterilization Methods on the Structural and Chemical Properties of Fibrin Microthread Scaffolds.

    Science.gov (United States)

    Grasman, Jonathan M; O'Brien, Megan P; Ackerman, Kevin; Gagnon, Keith A; Wong, Gregory M; Pins, George D

    2016-06-01

    A challenge for the design of scaffolds in tissue engineering is to determine a terminal sterilization method that will retain the structural and biochemical properties of the materials. Since commonly used heat and ionizing energy-based sterilization methods have been shown to alter the material properties of protein-based scaffolds, the effects of ethanol and ethylene oxide (EtO) sterilization on the cellular compatibility and the structural, chemical, and mechanical properties of uncrosslinked, UV crosslinked, or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) crosslinked fibrin microthreads in neutral (EDCn) or acidic (EDCa) buffers are evaluated. EtO sterilization significantly reduces the tensile strength of uncrosslinked microthreads. Surface chemistry analyses show that EtO sterilization induces alkylation of EDCa microthreads leading to a significant reduction in myoblast attachment. The material properties of EDCn microthreads do not appear to be affected by the sterilization method. These results significantly enhance the understanding of how sterilization or crosslinking techniques affect the material properties of protein scaffolds. PMID:26847494

  9. Physical and Chemical Properties of Some European Plum Cultivars (Prunus domestica L.

    Directory of Open Access Journals (Sweden)

    Mira Elena IONICA

    2013-12-01

    Full Text Available Fruits from twelve plum cultivars (Prunus domestica L., were analyzed in terms of physical and chemical characteristics. The fruits trees were grown in a trial at University of Craiova - Fruit Growing Research Station (SCDP Valcea, which is located in Bujoreni, an important Romanian plum production area. Fruits were picked at harvest maturity. Several analyzes were performed, such as fruit linear dimensions, size index, fruit weight, dry matter, soluble solids content, titratable acidity, total anthocyanins, malic, tartaric and citric acids content. The best features in terms of physical and chemical properties proved to be found in ‘Alina’, ‘Alutus’, ‘Tuleu Timpuriu’, ‘Oltenal’ and ‘Renclod Althan’.

  10. Effects of the manufacturing parameter and chemical composition on properties of HANA-4 cladding tube

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Yong; Kim, Yoon Ho; Jang, Hun; Choi, Min Young; Mok, Yong Kyoon [KEPCO Nuclear Fuel, Daejeon (Korea, Republic of)

    2015-05-15

    KEPCO NF conducted some researches to improve workability of HANA-4 cladding tube. It was changed to TREX outer diameter for increase Q-factor in first pilgering process related to the workability of cladding tube. In general, a increasing Q-factor leads to improvement yield of tubing manufacture in zirconium alloys. And decreasing of amount of alloying element changed cladding properties. The secondary phase particle analysis, the corrosion behavior and the texture were examined for HANA-4 alloys with adjustments of chemical compositions and TREX outer diameter for the purpose of enhancement formability. The precipitate type, size, and distribution of HANA-4 alloy were not changed as the chemical composition and the manufacturing parameters. The corrosion weight gain was decreased with reducing alloying elements, which considered the beneficial effect of reduced tin.

  11. Effects of the manufacturing parameter and chemical composition on properties of HANA-4 cladding tube

    International Nuclear Information System (INIS)

    KEPCO NF conducted some researches to improve workability of HANA-4 cladding tube. It was changed to TREX outer diameter for increase Q-factor in first pilgering process related to the workability of cladding tube. In general, a increasing Q-factor leads to improvement yield of tubing manufacture in zirconium alloys. And decreasing of amount of alloying element changed cladding properties. The secondary phase particle analysis, the corrosion behavior and the texture were examined for HANA-4 alloys with adjustments of chemical compositions and TREX outer diameter for the purpose of enhancement formability. The precipitate type, size, and distribution of HANA-4 alloy were not changed as the chemical composition and the manufacturing parameters. The corrosion weight gain was decreased with reducing alloying elements, which considered the beneficial effect of reduced tin

  12. Customizing Properties of β-Chitin in Squid Pen (Gladius by Chemical Treatments

    Directory of Open Access Journals (Sweden)

    Alessandro Ianiro

    2014-12-01

    Full Text Available The squid pen (gladius from the Loligo vulgaris was used for preparation of β-chitin materials characterized by different chemical, micro- and nano-structural properties that preserved, almost completely the macrostructural and the mechanical ones. The β-chitin materials obtained by alkaline treatment showed porosity, wettability and swelling that are a function of the duration of the treatment. Microscopic, spectroscopic and synchrotron X-ray diffraction techniques showed that the chemical environment of the N-acetyl groups of the β-chitin chains changes after the thermal alkaline treatment. As a consequence, the crystalline packing of the β-chitin is modified, due to the intercalation of water molecules between β-chitin sheets. Potential applications of these β-chitin materials range from the nanotechnology to the regenerative medicine. The use of gladii, which are waste products of the fishing industry, has also important environmental implications.

  13. Chemical composition and functional properties of starch extracted from the pejibaye fruit (Bactris gasepaes Kunth.

    Directory of Open Access Journals (Sweden)

    Biano Alves de Melo Neto

    2015-01-01

    Full Text Available This study aimed to establish the chemical composition and functional properties of the starch extracted from the pejibaye fruit (Bactris gasepaes Kunth.. The chemical characterization was evaluated from the determination of starch, amylose, amylopectin, total lipid, protein, ash, moisture and water activity. The water absorption index and the water solubility index were calculated for temperatures between 25 and 90ºC. Low contents of ash and protein were found. The studied starch has 14% moisture, according to the established by law. The water activity value was 0.55, which ensures its microbiological stability. A range of gelatinization between 65 to 70ºC was observed, close to the one of commercial starches. The solubility rate in water was 0.6119% and the absorption rate in water was 1.8252%. These results demonstrated that the starch from the pejibaye fruit has important characteristics for use in the food industry.

  14. Diffusion, Thermal Properties and Chemical Compatibilities of Select MAX Phases with Materials For Advanced Nuclear Systems

    Energy Technology Data Exchange (ETDEWEB)

    Barsoum, Michel [Drexel Univ., Philadelphia, PA (United States); Bentzel, Grady [Drexel Univ., Philadelphia, PA (United States); Tallman, Darin J. [Drexel Univ., Philadelphia, PA (United States); Sindelar, Robert [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Garcia-Diaz, Brenda [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hoffman, Elizabeth [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-04-04

    The demands of Gen IV nuclear power plants for long service life under neutron irradiation at high temperature are severe. Advanced materials that would withstand high temperatures (up to 1000+ ºC) to high doses in a neutron field would be ideal for reactor internal structures and would add to the long service life and reliability of the reactors. The objective of this work is to investigate the chemical compatibility of select MAX with potential materials that are important for nuclear energy, as well as to measure the thermal transport properties as a function of neutron irradiation. The chemical counterparts chosen for this work are: pyrolytic carbon, SiC, U, Pd, FLiBe, Pb-Bi and Na, the latter 3 in the molten state. The thermal conductivities and heat capacities of non-irradiated MAX phases will be measured.

  15. The Surface Chemical Composition of Lunar Samples and Its Significance for Optical Properties

    Science.gov (United States)

    Gold, T.; Bilson, E.; Baron, R. L.

    1976-01-01

    The surface iron, titanium, calcium, and silicon concentration in numerous lunar soil and rock samples was determined by Auger electron spectroscopy. All soil samples show a large increase in the iron to oxygen ratio compared with samples of pulverized rock or with results of the bulk chemical analysis. A solar wind simulation experiment using 2 keV energy alpha -particles showed that an ion dose corresponding to approximately 30,000 years of solar wind increased the iron concentration on the surface of the pulverized Apollo 14 rock sample 14310 to the concentration measured in the Apollo 14 soil sample 14163, and the albedo of the pulverized rock decreased from 0.36 to 0.07. The low albedo of the lunar soil is related to the iron + titanium concentration on its surface. A solar wind sputter reduction mechanism is discussed as a possible cause for both the surface chemical and optical properties of the soil.

  16. Chemical and functional properties of fibre concentrates obtained from by-products of coconut kernel.

    Science.gov (United States)

    Yalegama, L L W C; Nedra Karunaratne, D; Sivakanesan, Ramiah; Jayasekara, Chitrangani

    2013-11-01

    The coconut kernel residues obtained after extraction of coconut milk (MR) and virgin coconut oil (VOR) were analysed for their potential as dietary fibres. VOR was defatted and treated chemically using three solvent systems to isolate coconut cell wall polysaccharides (CCWP). Nutritional composition of VOR, MR and CCWPs indicated that crude fibre, neutral detergent fibre, acid detergent fibre and hemicelluloses contents were higher in CCWPs than in VOR and MR. MR contained a notably higher content of fat than VOR and CCWPs. The oil holding capacity, water holding capacity and swelling capacity were also higher in CCWPs than in VOR and MR. All the isolates and MR and VOR had high metal binding capacities. The CCWPs when compared with commercially available fibre isolates, indicated improved dietary fibre properties. These results show that chemical treatment of coconut kernel by-products can enhance the performance of dietary fibre to yield a better product.

  17. Property Model-based Tailor-made Design of Chemical-based Products

    DEFF Research Database (Denmark)

    Kalakul, Sawitree

    on experiment are reduced leading to faster and cheaper to market the products. The tools also help to manage the solution of product design problems, which usually require efficient handling of model-data-knowledge from different sources and at different time and size scales. The main contribution...... framework for chemical product design and analysis and its implementation as architecture for VPPD-Lab. From many test problems, eight application examples are presented to illustrate the use of the software. For two of these examples, the prediction of product properties and the use of virtual experiments...... of this project is: (1) the development of a systematic model-based framework for chemical product design; (2) its implementation as a computer-aided tool based on a specially developed architecture; (3) the creation of product design template together with their algorithms, models, tools and data for various...

  18. Chemical characteristics of straw fiber and properties of straw fiberboard with different pretreatments

    Institute of Scientific and Technical Information of China (English)

    PAN Mingzhu; LIAN Hailan; ZHOU Dingguo

    2007-01-01

    Surface chemical characteristics of straw fiber have a great effect on the properties of interfacial conglutination between straw fiber and adhesives.In our study,straw was treated by four different methods-hot water,acetic acid,sodium sulfite and sodium hydrid sulfite.Our results show that the main chemical group of straw fiber,under the four different treatments,has not changed significantly.The acetic acid treatment reduces pH values of straw fibers and has a significant effect on the internal bonding strength of straw fiberboards.The modulus of rupture and modulus of elasticity did not clearly improve with the four different treatments.The thickness swelling of straw fiberboard treated in different ways is higher than that of standard values.It is concluded that acid treatment is optimal for producing good quality straw fiberboard.

  19. Investigation of Chemical Bond Properties and Mssbauer Spectroscopy in YBa2Cu3O7

    Institute of Scientific and Technical Information of China (English)

    高发明; 李东春; 张思远

    2003-01-01

    Chemical bond properties of YBa2Cu3O7 were studied by using the average band-gap model. The calculated results show that the covalency of Cu(1)-O bond is 0.406, and one of Cu(2)-O is 0.276. Mssbauer isomer shifts of 57Fe in Y-123 were calculated by the chemical surrounding factor hv defined by covalency and electronic polarizability. The charge-state and site of Fe were determined. The relation between the coupling constant of electron-phonon interaction and covalency is employed to explain that the Cu(2)-O plane is more important than the Cu(1)-O chain on the superconductivity in the Y-123 compounds.

  20. Physical and chemical properties and compositions of liquid effluents of a nuclear power reactor

    International Nuclear Information System (INIS)

    Behaviours of the released radioactive materials from a nuclear power plant to the marine environment depend largely on their physical and chemical properties. It is therefore important to grasp the compositions of the liquid effluents. From this point of view, some kinds of drainwater of a BWR plant were sampled. These samples are the laundry drain water at charcoal bed inlet and outlet, and the floor drain water. Suspended solids were separated from these samples physically with the step filtration method and ions chemically with the ion exchange resin. Radioactivity of Co-60, Mn-54 and Cs-137 was measured with γ spectrometer. Suspended solids of the laundry drain samples were also analysed with the instrumental methods (differential thermal analysis, x-ray diffraction analysis and x-ray fluorescence analysis)

  1. Diffusion, Thermal Properties and Chemical Compatibilities of Select MAX Phases with Materials For Advanced Nuclear Systems

    Energy Technology Data Exchange (ETDEWEB)

    Barsoum, Michel [Drexel Univ., Philadelphia, PA (United States); Bentzel, Grady [Drexel Univ., Philadelphia, PA (United States); Tallman, Darin J. [Drexel Univ., Philadelphia, PA (United States); Sindelar, Robert [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Garcia-Diaz, Brenda [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hoffman, Elizabeth [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-04-04

    The demands of Gen IV nuclear power plants for long service life under neutron irradiation at high temperature are severe. Advanced materials that would withstand high temperatures (up to 1000+ ºC) to high doses in a neutron field would be ideal for reactor internal structures and would add to the long service life and reliability of the reactors. The objective of this work is to investigate the chemical compatibility of select MAX with potential materials that are important for nuclear energy, as well as, to measure the thermal transport properties as a function of neutron irradiation. The chemical counterparts chosen for this work are: pyrolytic carbon, SiC, U, Pd, FLiBe, Pb-Bi and Na; the latter 3 in the molten state. The thermal conductivities and heat capacities of non-irradiated MAX phases will be measured.

  2. Chemical and mechanical performance properties for various final waste forms -- PSPI scoping study

    Energy Technology Data Exchange (ETDEWEB)

    Farnsworth, R.K.; Larsen, E.D.; Sears, J.W.; Eddy, T.L.; Anderson, G.L.

    1996-09-01

    The US DOE is obtaining data on the performance properties of the various final waste forms that may be chosen as primary treatment products for the alpha-contaminated low-level and transuranic waste at the INEL`s Transuranic Storage Area. This report collects and compares selected properties that are key indicators of mechanical and chemical durability for Portland cement concrete, concrete formed under elevated temperature and pressure, sulfur polymer cement, borosilicate glass, and various forms of alumino-silicate glass, including in situ vitrification glass and various compositions of iron-enriched basalt (IEB) and iron-enriched basalt IV (IEB4). Compressive strength and impact resistance properties were used as performance indicators in comparative evaluation of the mechanical durability of each waste form, while various leachability data were used in comparative evaluation of each waste form`s chemical durability. The vitrified waste forms were generally more durable than the non-vitrified waste forms, with the iron-enriched alumino-silicate glasses and glass/ceramics exhibiting the most favorable chemical and mechanical durabilities. It appears that the addition of zirconia and titania to IEB (forming IEB4) increases the leach resistance of the lanthanides. The large compositional ranges for IEB and IEB4 more easily accommodate the compositions of the waste stored at the INEL than does the composition of borosilicate glass. It appears, however, that the large potential variation in IEB and IEB4 compositions resulting from differing waste feed compositions can impact waste form durability. Further work is needed to determine the range of waste stream feed compositions and rates of waste form cooling that will result in acceptable and optimized IEB or IEB4 waste form performance. 43 refs.

  3. Structural, optical and electrical properties of chemically deposited copper selenide films

    Indian Academy of Sciences (India)

    R H Bari; V Ganesan; S Potadar; L A Patil

    2009-02-01

    Stoichiometric and nonstoichiometric thin films of copper selenide have been prepared by chemical bath deposition technique at temperature below 60°C on glass substrate. The effect of nonstoichiometry on the optical, electrical and structural properties of the film was studied. The bandgap energy was observed to increase with the increase in at % of copper in composition. The grain size was also observed to increase with the decrease of at % of copper in composition. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), absorption spectroscopy, and AFM. The results are discussed and interpreted.

  4. Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition

    OpenAIRE

    K. A. Kamilli; L. Poulain; A. Held; Nowak, A.; Birmili, W.; Wiedensohler, A.

    2014-01-01

    Aerosol hygroscopic growth factors and chemical properties were measured as part of the MEGAPOLI "Megacities Plume Case Study" at the urban site Laboratoire d'Hygiène de la Ville de Paris (LHVP) in the city center of Paris from June to August 2009, and from January to February 2010. Descriptive hygroscopic growth factors (DGF) were derived in the diameter range from 25 to 350 nm at relative humidities of 30, 55, 75, and 90% by applying the summation method on humidified and ...

  5. SOME PHYSICAL AND CHEMICAL PROPERTIES OF THE RICE GROWN SOILS OF CENTRAL ANATOLIA REGION

    OpenAIRE

    TABAN, SÜleyman; Alpaslan, Mehmet; HASHEMI, Aioub G.; EKEN, Dürdane

    1997-01-01

    The aim of this study was to determine the fertility status of the rice grown soils of Central Anatolia region. For this purpose, 40 soil samples were taken and analyzed for some physical and chemical properties. In general, the experimental soils were clay and loamy clay in texture, medium alkaline in reaction (pH) and moderately calcareous. 60, 25, 30 and 95 % of the soils studied were found to be deficient in total-N, plant available phosphorus, zinc and manganese, respectively. On the ot...

  6. Synthesis, mechanical, thermal and chemical properties of polyurethanes based on cardanol

    Indian Academy of Sciences (India)

    C V Mythili; A Malar Retna; S Gopalakrishnan

    2004-06-01

    Cardanol, an excellent monomer for polymer production, has been isolated from CNSL and allowed to react with formaldehyde in a particular mole ratio in the presence of glutaric acid catalyst to give high-ortho novolac resin. Such characterized polyol has been condensed with diphenylmethane diisocyanate to produce rigid polyurethane. A commercially available polyol, polypropylene glycol-2000 (PPG-2000), has also been condensed with diphenylmethane diisocyanate and polyol to produce tough polyurethane. These polyurethanes were characterized with respect to their resistance to chemical reagents and mechanical properties such as tensile strength, percentage elongation, tear strength and hardness. Differential thermal analysis (DTA) and thermo-gravimetric analysis (TGA) were undertaken for thermal characterization.

  7. Modelling of Physical, Chemical, and Material Properties of Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Jakub Kupecki

    2015-01-01

    Full Text Available This paper provides a review of modelling techniques applicable for system-level studies to account for physical, chemical, and material properties of solid oxide fuel cells. Functionality of 0D to 3D models is discussed and selected examples are given. Author provides information on typical length scales in evaluation of power systems with solid oxide fuel cells. In each section, proper examples of previous studies done in the field of 0D–3D modelling are recalled and discussed.

  8. Processing–structure–property relations of chemically bonded phosphate ceramic composites

    Indian Academy of Sciences (India)

    H A Colorado; C Hiel; H T Hahn

    2011-07-01

    Mechanical properties and microstructures of a chemically bonded phosphate ceramic (CBPC) and its composite with 1.0 wt% graphite nanoplatelets (GNPs) reinforcement have been investigated. Microstructure was identified by using optical and scanning electron microscopes, X-ray tomography, and X-ray diffraction. In addition, weight loss of the resin at room temperature was studied. The microstructure characterization shows that CBPC is itself a composite with several crystalline (wollastonite and brushite) and amorphous phases. SEM and micro tomography show a homogeneous distribution of crystalline phases. Bending and compression strength of the CBPC was improved by reducing bubbles via preparation in vacuum.

  9. Chemical, electronic, and magnetic structure of LaFeCoSi alloy: Surface and bulk properties

    Energy Technology Data Exchange (ETDEWEB)

    Lollobrigida, V. [Dipartimento di Scienze, Università Roma Tre, I-00146 Rome (Italy); Dipartimento di Matematica e Fisica, Università Roma Tre, I-00146 Rome (Italy); Basso, V.; Kuepferling, M.; Coïsson, M.; Olivetti, E. S.; Celegato, F. [Istituto Nazionale di Ricerca Metrologica (INRIM), I-10135 Torino (Italy); Borgatti, F. [CNR, Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), I-40129 Bologna (Italy); Torelli, P.; Panaccione, G. [CNR, Istituto Officina dei Materiali (IOM), Lab. TASC, I-34149 Trieste (Italy); Tortora, L. [Laboratorio di Analisi di Superficie, Dipartimento di Matematica e Fisica, Università Roma Tre, I-00146 Rome (Italy); Dipartimento di Ingegneria Meccanica, Università Tor Vergata, I-00133 Rome (Italy); Stefani, G.; Offi, F. [Dipartimento di Scienze, Università Roma Tre, I-00146 Rome (Italy)

    2014-05-28

    We investigate the chemical, electronic, and magnetic structure of the magnetocaloric LaFeCoSi compound with bulk and surface sensitive techniques. We put in evidence that the surface retains a soft ferromagnetic behavior at temperatures higher than the Curie temperature of the bulk due to the presence of Fe clusters at the surface only. This peculiar magnetic surface effect is attributed to the exchange interaction between the ferromagnetic Fe clusters located at the surface and the bulk magnetocaloric alloy, and it is used here to monitor the magnetic properties of the alloy itself.

  10. Cassava Peels for Alternative Fibre in Pulp and Paper Industry: Chemical Properties and Morphology Characterization

    OpenAIRE

    Ashuvila Mohd Aripin; Angzzas Sari Mohd Kassim; Zawawi Daud; Mohd Zainuri Mohd Hatta

    2013-01-01

    Without a proper waste management, the organic wastes such as cassava peels could result in increased amount of solid waste dump into landfill. This study aims to use non-wood organic wastes as pulp for paper making industries; promoting the concept of ‘from waste to wealth and recyclable material’. The objective  of this study is to determine the potential of casssava peel as alternative fibre in pulp and paper based on its chemical properties and surface morphology characteristic. Quantifie...

  11. Magnetic property and recording performance of chemical deposition CoP thin films

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The thickness of CoP thin films prepared by wet chemical deposition is of crucial importance on magnetic property and recording perform-ance. The coercivity of CoP films decreased with increasing film thickness. The coercivity was 45.37 kA m 1 at the thickness of 300 nm, and decreased to 21.65 kA m 1 at 5.7 μm. Recording performance tests indicate that, for drums with the same size, different recorded magnetic pole density have different thickness requirements. For 40 mm diameter magnetic drum, the optimal ...

  12. Potassium fertilization for pineapple: effects on soil chemical properties and plant nutrition

    OpenAIRE

    Luiz Antonio Junqueira Teixeira; José Antonio Quaggio; Heitor Cantarella; Estêvão Vicari Mellis

    2011-01-01

    A field experiment was carried out on an Ultisol located at the city of Agudos (22º30'S; 49º03'W), in the state of São Paulo, Brazil, in order to determine the effects of rates and sources of potassium fertilizer on nutritional status of 'Smooth Cayenne' pineapple and on some soil chemical properties. The experiment was a complete factorial design with four rates (0, 175, 350, and 700 kg ha-1 of K2O) and three combinations of K sources (100% KCl, 100% K2SO4 and 40% K2SO4 + 60% KCl). Soil samp...

  13. Chemical, electronic, and magnetic structure of LaFeCoSi alloy: Surface and bulk properties

    International Nuclear Information System (INIS)

    We investigate the chemical, electronic, and magnetic structure of the magnetocaloric LaFeCoSi compound with bulk and surface sensitive techniques. We put in evidence that the surface retains a soft ferromagnetic behavior at temperatures higher than the Curie temperature of the bulk due to the presence of Fe clusters at the surface only. This peculiar magnetic surface effect is attributed to the exchange interaction between the ferromagnetic Fe clusters located at the surface and the bulk magnetocaloric alloy, and it is used here to monitor the magnetic properties of the alloy itself.

  14. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods

    OpenAIRE

    Inderjeet Kaur; Neelam Sharma; Vandna Kumari

    2013-01-01

    Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.8...

  15. Influence of chemical heat treatment on the mechanical properties of paper knife-edge die

    OpenAIRE

    K. Dybowski; Kaczmarek, Ł.; R. Pietrasik; J. Smolik; Ł. Kołodziejczyk; Batory, D.; Gzik, M; M. Stegliński

    2009-01-01

    Purpose: In this article mechanical properties together with wear mechanism of paper knife-edge die made of A 681 steel with TiN, TiCN and DLC coating were analyzed. A Paper knife-edge die using in stamping machine, serves a map of complicated graphical projects. However wear resistance is strongly dependent on chemical composition of a paper mainly on the TiO2 content.Design/methodology/approach: In order to optimize the wear resistance of analyzed paper knife-edge die, influence of HS6-5-2 ...

  16. Inference of Surface Chemical and Physical Properties Using Mid-Infrared (MIR) Spectral Observations

    Science.gov (United States)

    Roush, Ted L.

    2016-01-01

    Reflected or emitted energy from solid surfaces in the solar system can provide insight into thermo-physical and chemical properties of the surface materials. Measurements have been obtained from instruments located on Earth-based telescopes and carried on several space missions. The characteristic spectral features commonly observed in Mid-Infrared (MIR) spectra of minerals will be reviewed, along with methods used for compositional interpretations of MIR emission spectra. The influence of surface grain size, and space weathering processes on MIR emissivity spectra will also be discussed. Methods used for estimating surface temperature, emissivity, and thermal inertias from MIR spectral observations will be reviewed.

  17. Computational Nutraceutics: Chemical Reactivity Properties of the Flavonoid Naringin by Means of Conceptual DFT

    Directory of Open Access Journals (Sweden)

    Jorge Ignacio Martínez-Araya

    2013-01-01

    Full Text Available The M06 family of density functionals has been assessed for the calculation of the molecular structure and properties of the Naringin molecule. The chemical reactivity descriptors have been calculated through Conceptual DFT. The active sites for nucleophilic and electrophilic attacks have been chosen by relating them to the Fukui function indices and the dual descriptor f(2(r. A comparison between the descriptors calculated through vertical energy values and those arising from the Koopmans' theorem approximation has been performed in order to check for the validity of the last procedure.

  18. Load transfer and mechanical properties of chemically reduced graphene reinforcements in polymer composites

    International Nuclear Information System (INIS)

    We report load transfer and mechanical properties of chemically derived single layer graphene (SLG) as reinforcements in poly (dimethyl) siloxane (PDMS) composites. Shear mixing reduced graphene sheets in polymers resulted in a marked decrease of the 2D band intensity due to doping and functionalization. Raman G mode shifts of 11.2 cm−1/% strain in compression and 4.2 cm−1/% strain in tension are reported. Increases in elastic modulus of PDMS by ∼42%, toughness by ∼39%, damping capability by ∼673%, and strain energy density of ∼43% by the addition of 1 wt% SLG in PDMS are reported. (paper)

  19. Analysis of the Engineering Restoration Effect of Abandoned Yongledian Quarry in Beijing City Based on Soil Physical and Chemical Properties

    Institute of Scientific and Technical Information of China (English)

    Liwei; CAI

    2014-01-01

    The improvement of the soil physical and chemical properties is the most important foundation for mine ecological restoration.The experiment is aimed at undisturbed area,restored area,and damaged area of abandoned Yongledian Quarry in Beijing.Through determination and analysis of soil physical and chemical properties,it shows that there are significant differences in the composite effects of soil physical and chemical properties between restored area,and undisturbed area,damaged area,and engineering restoration effectively improves the composite effects of soil physical and chemical properties in the restored area.The single factor hypothesis test shows that soil pH value,organic matter,alkali-hydrolyzable nitrogen,and total nitrogen traits are the key targets to be restored in this mining area.

  20. Influence of deposition time on the properties of chemical bath deposited manganese sulfide thin films

    Directory of Open Access Journals (Sweden)

    Anuar Kassim

    2010-12-01

    Full Text Available Manganese sulfide thin films were chemically deposited from an aqueous solution containing manganese sulfate, sodium thiosulfate and sodium tartrate. The influence of deposition time (2, 3, 6 and 8 days on the properties of thin films was investigated. The structure and surface morphology of the thin films were studied by X-ray diffraction and atomic force microscopy, respectively. In addition, in order to investigate the optical properties of the thin films, the UV-visible spectrophotometry was used. The XRD results indicated that the deposited MnS2 thin films exhibited a polycrystalline cubic structure. The number of MnS2 peaks on the XRD patterns initially increased from three to six peaks and then decreased to five peaks, as the deposition time was increased from 2 to 8 days. From the AFM measurements, the film thickness and surface roughness were found to be dependent on the deposition time.

  1. Effect of shifting cultivation on soil physical and chemical properties in Bandarban hill district, Bangladesh

    Institute of Scientific and Technical Information of China (English)

    Khandakar Showkat Osman; M. Jashimuddin; S. M. Sirajul Haque; Sohag Miah

    2013-01-01

    This study reports the effects of shifting cultivation at slashing stage on soil physicochemical properties at Bandarban Sadar Upazila in Chittagong Hill Tracts of Bangladesh. At this initial stage of shifting cultivation no general trend was found for moisture content, maximum water holding capacity, field capacity, dry and moist bulk density, parti-cle density for some chemical properties between shifting cultivated land and forest having similar soil texture. Organic matter was significantly (p≤0.05) lower in 1-year and 3-year shifting cultivated lands and higher in 2-year shifting cultivation than in adjacent natural forest. Significant differences were also found for total N, exchangeable Ca, Mg and K and in CEC as well as for available P. Slashed area showed higher soil pH. Deterioration in land quality starts from burning of slashing materials and continues through subsequent stages of shifting cultivation.

  2. Structural and optical properties of tellurium films obtained by chemical vapor deposition(CVD)

    Institute of Scientific and Technical Information of China (English)

    MA Yu-tian; GONG Zhu-Qing; XU Wei-Hong; HUANG Jian

    2006-01-01

    Tellurium thin films were prepared by the chemical vapor deposition method. The structure, surface morphology and optical properties of the Te thin films were analyzed by powder X-ray diffraction, scanning electron microscopy, FTIR transmission,UV/VIS/NIR transmission and reflectance. The results show that the films structural and optical properties are influenced by many factors such as film thickness, crystallite size and substrate temperature. The films as thick as 111-133 nm have high IR transmission across the full 8-13 μm band and highly blocking in the solar spectral region elsewhere, which indicates that Te films thickness in this region can be used as good solar radiation shields in radiative cooling devices.

  3. Physico-chemical and antioxidant properties of two medicinal wild plants grown in Moldova region

    Directory of Open Access Journals (Sweden)

    Sorina Ropciuc

    2015-05-01

    Full Text Available The major objective of this study is to report physico-chemical (moisture, ash, protein, total phenolic compounds and ascorbic acid and the antioxidant properties of methanol extracts of nettle (Urtica dioica L. and typical romaine spice "leurda" (Allium ursinum, wild garlic fresh and dried. The antioxidant properties of methanol extract of medicinal herbs were evaluated using free radical scavenging test. The phenols were extracted from the medicinal plants with methanol solvent and were quantified by the Folin-Ciocalteu method. The ascorbic acid content varied between 77.94 mg/100g in the fresh Urtica dioica L. and 39.55 from fresh Allium ursinum. The results showed that the total phenolic compounds in all medicinal plants decreased along processing. These results suggest that the medicinal plants sample extract with highest polyphenolic content will indicates the possibility of using them  as ingredients in functional foods.

  4. Assessment of quantum-chemical methods for electronic properties and geometry of signaling biomolecules.

    Science.gov (United States)

    Ferro, Noel; Bredow, Thomas

    2010-04-15

    A reasonable balance between accuracy and feasibility of quantum-chemical methods depends on the complexity of the molecular system and the scientific goals. Six series of indole-, naphthalene-, phenol-, benzoic-, phenoxy-, other auxin-derivatives, and a test set of similar organic molecules have been chosen for an assessment of 13 density functional and semi-empirical molecular orbital methods with respect to electronic and structural properties. The accuracy and precision of HOMO/LUMO calculations are determined by comparison with experimental ionization potentials and electron affinities. Further comparison was performed at atomic level by covariance analysis. The methods KMLYP, MSINDO, and PM3 are precise and accurate for the whole set of molecules. The method AM1 offers comparable accuracy with the exception of electron affinities of indole derivatives, where significant deviations from experiment were observed. Geometrical properties were best reproduced with the semi-empirical method MSINDO. PMID:19899146

  5. Evaluating changes of transport properties of chemically degrading concrete using a coupled reactive transport model

    International Nuclear Information System (INIS)

    This paper presents a model to simulate chemical degradation of concrete due to leaching. The model considers simultaneously the multi-scale nature of concrete, a thermodynamic description of cement phases, and time-variable transport properties. It is implemented in the generic simulator HP1, which simulates the reactive transport in variably-saturated porous media. To illustrate the capabilities of the program, we simulate diffusive transport through concrete in contact with waters of different solution compositions (i.e., concentrations of major cations and anions and inorganic carbon contents) and use a homogenization scheme for up-scaling tortuosity. The simulations show the coupled effects between geochemical state variables, transport properties, and durability criteria for cementitious materials used in near-surface radioactive waste disposal facilities. (authors)

  6. Effects of bioleaching on the mechanical and chemical properties of waste rocks

    Science.gov (United States)

    Yin, Sheng-Hua; Wu, Ai-Xiang; Wang, Shao-Yong; Ai, Chun-Ming

    2012-01-01

    Bioleaching processes cause dramatic changes in the mechanical and chemical properties of waste rocks, and play an important role in metal recovery and dump stability. This study focused on the characteristics of waste rocks subjected to bioleaching. A series of experiments were conducted to investigate the evolution of rock properties during the bioleaching process. Mechanical behaviors of the leached waste rocks, such as failure patterns, normal stress, shear strength, and cohesion were determined through mechanical tests. The results of SEM imaging show considerable differences in the surface morphology of leached rocks located at different parts of the dump. The mineralogical content of the leached rocks reflects the extent of dissolution and precipitation during bioleaching. The dump porosity and rock size change under the effect of dissolution, precipitation, and clay transportation. The particle size of the leached rocks decreased due to the loss of rock integrity and the conversion of dry precipitation into fine particles.

  7. Chemical vapor deposition polymerization the growth and properties of parylene thin films

    CERN Document Server

    Fortin, Jeffrey B

    2004-01-01

    Chemical Vapor Deposition Polymerization - The Growth and Properties of Parylene Thin Films is intended to be valuable to both users and researchers of parylene thin films. It should be particularly useful for those setting up and characterizing their first research deposition system. It provides a good picture of the deposition process and equipment, as well as information on system-to-system variations that is important to consider when designing a deposition system or making modifications to an existing one. Also included are methods to characterizae a deposition system's pumping properties as well as monitor the deposition process via mass spectrometry. There are many references that will lead the reader to further information on the topic being discussed. This text should serve as a useful reference source and handbook for scientists and engineers interested in depositing high quality parylene thin films.

  8. On the relation between chemical composition and optical properties of detonation nanodiamonds

    KAUST Repository

    Kirmani, Ahmad R.

    2015-06-23

    The morphology and presence of impurities strongly influence mechanical, optical, electrical, and thermal properties of detonation nanodiamonds (DNDs). Here we report insights on the chemical composition and its effect on the optical properties of the DNDs obtained by rate-zonal density gradient ultracentrifugation. Herein, for the first time, a detailed valence band structure of as-prepared and oxidized DNDs is reported. Photoemission spectroscopy (PES) measurements demonstrate that the defects, originating from fullerene-like C bonding in the sp2 shells of the DNDs, are governing the literature-reported loss of the emission spectral features arising from the nitrogen-vacancy (NV) center excitations. X-ray photoelectron spectroscopy (XPS) measurements reveal that nitrogen is present in the DNDs in the form of N–O bonded species located at the surface region/sp2 shells, while in core of the DND it is in the form of N–C/N=C species.

  9. Diesel Surrogate Fuels for Engine Testing and Chemical-Kinetic Modeling: Compositions and Properties

    Science.gov (United States)

    Mueller, Charles J.; Cannella, William J.; Bays, J. Timothy; Bruno, Thomas J.; DeFabio, Kathy; Dettman, Heather D.; Gieleciak, Rafal M.; Huber, Marcia L.; Kweon, Chol-Bum; McConnell, Steven S.; Pitz, William J.; Ratcliff, Matthew A.

    2016-01-01

    The primary objectives of this work were to formulate, blend, and characterize a set of four ultralow-sulfur diesel surrogate fuels in quantities sufficient to enable their study in single-cylinder-engine and combustion-vessel experiments. The surrogate fuels feature increasing levels of compositional accuracy (i.e., increasing exactness in matching hydrocarbon structural characteristics) relative to the single target diesel fuel upon which the surrogate fuels are based. This approach was taken to assist in determining the minimum level of surrogate-fuel compositional accuracy that is required to adequately emulate the performance characteristics of the target fuel under different combustion modes. For each of the four surrogate fuels, an approximately 30 L batch was blended, and a number of the physical and chemical properties were measured. This work documents the surrogate-fuel creation process and the results of the property measurements. PMID:27330248

  10. Soil uses during the sugarcane fallow period: influence on soil chemical and physical properties and on sugarcane productivity

    OpenAIRE

    Roniram Pereira da Silva; Carolina Fernandes

    2014-01-01

    The planting of diversified crops during the sugarcane fallow period can improve the chemical and physical properties and increase the production potential of the soil for the next sugarcane cycle. The primary purpose of this study was to assess the influence of various soil uses during the sugarcane fallow period on soil chemical and physical properties and productivity after the first sugarcane harvest. The experiment was conducted in two areas located in Jaboticabal, São Paulo State, Brazi...

  11. Optical, physical and chemical properties of transported African mineral dust aerosols in the Mediterranean region

    Science.gov (United States)

    Denjean, Cyrielle; Di Biagio, Claudia; Chevaillier, Servanne; Gaimoz, Cécile; Grand, Noel; Loisil, Rodrigue; Triquet, Sylvain; Zapf, Pascal; Roberts, Greg; Bourrianne, Thierry; Torres, Benjamin; Blarel, Luc; Sellegri, Karine; Freney, Evelyn; Schwarzenbock, Alfons; Ravetta, François; Laurent, Benoit; Mallet, Marc; Formenti, Paola

    2014-05-01

    The transport of mineral dust aerosols is a global phenomenon with strong climate implications. Depending on the travel distance over source regions, the atmospheric conditions and the residence time in the atmosphere, various transformation processes (size-selective sedimentation, mixing, condensation of gaseous species, and weathering) can modify the physical and chemical properties of mineral dust, which, in turn, can change the dust's optical properties. The model predictions of the radiative effect by mineral dust still suffer of the lack of certainty of these properties, and their temporal evolution with transport time. Within the frame of the ChArMex project (Chemistry-Aerosol Mediterranean experiment, http://charmex.lsce.ipsl.fr/), two intensive airborne campaigns (TRAQA, TRansport and Air QuAlity, 18 June - 11 July 2012, and ADRIMED, Aerosol Direct Radiative Impact in the regional climate in the MEDiterranean region, 06 June - 08 July 2013) have been performed over the Central and Western Mediterranean, one of the two major transport pathways of African mineral dust. In this study we have set up a systematic strategy to determine the optical, physical and optical properties of mineral dust to be compared to an equivalent dataset for dust close to source regions in Africa. This study is based on airborne observations onboard the SAFIRE ATR-42 aircraft, equipped with state of the art in situ instrumentation to measure the particle scattering and backscattering coefficients (nephelometer at 450, 550, and 700 nm), the absorption coefficient (PSAP at 467, 530, and 660 nm), the extinction coefficient (CAPS at 530 nm), the aerosol optical depth (PLASMA at 340 to 1640 nm), the size distribution in the extended range 40 nm - 30 µm by the combination of different particle counters (SMPS, USHAS, FSSP, GRIMM) and the chemical composition obtained by filter sampling. The chemistry and transport model CHIMERE-Dust have been used to classify the air masses according to

  12. Critically Evaluated Database of Environmental Properties: The Importance of Thermodynamic Relationships, Chemical Family Trends, and Prediction Methods

    Science.gov (United States)

    Brockbank, Sarah A.; Russon, Jenna L.; Giles, Neil F.; Rowley, Richard L.; Wilding, W. Vincent

    2013-11-01

    A database containing Henry's law constants, infinite dilution activity coefficients, and solubility data of industrially important chemicals has been compiled for aqueous systems. These properties are important in predicting the fate and transport of chemicals in the environment. The structure of this database is compatible with the existing 801 database and DIADEM interface, and data are included for a subset of compounds found in the 801 database. Thermodynamic relationships, chemical family trends, and predicted values were carefully considered when designating recommended values.

  13. Properties of baryonic, electric and strangeness chemical potentials and some of their consequences in relativistic heavy ion collisions

    CERN Document Server

    Mekjian, Aram Z

    2007-01-01

    Analytic expressions are given for the baryonic, electric and strangeness chemical potentials which explicitly show the importance of various terms. Simple scaling relations connecting these chemical potentials are found. Applications to particle ratios and to fluctuations and related thermal properties such as the isothermal compressibility kappaT are illustrated. A possible divergence of kappaT is discussed.

  14. Effect of Binders on Porous Properties, Surface Chemical Properties and Adsorption Characteristics of Granular Adsorbents from Sewage Sludge

    Directory of Open Access Journals (Sweden)

    Liheng LIU

    2014-12-01

    Full Text Available To investigate the influence of binders on porous properties, surface chemical properties and methylene blue adsorption characteristics of granular adsobnts from sewage sludge, four samples(G1, G2, G3 and G4 respectively using soluble starch, sodium carboxymethyl cellulose, sodium silicate and calcium sulfate as binders and a sample without binder (G0 were prepared by carbonization method. The pore structure and surface characterization of samples prepared show that G1 and G2 have many microporous and mesoporous pores while the activation of sodium silicate and calcium sulfate cause that G1 and G2 are typical mesoporous adsorbents. The FTIR spectra of all samples suggest that the major differences of surface functional groups are between 1000-1200 cm-1 and 400-800 cm-1. Langmuir model fitted the methylene blue (MB adsorption data better, and the MB adsorption of G0, G1, G2, G3 and G4 are 56.50, 40.32, 33.44, 29.33 and 71.94mg/g, respectively. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6031

  15. The physical and chemical properties of polymerization reaction for contact lens irradiated by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Sin, Junghyeok; Jun, Jin [Dongshin Univ., Naju (Korea, Republic of)

    2010-07-01

    Can EB irradiation be possible the polymerization of HEMA without the cross-linker and initiator? The physical and chemical properties of the polymers are compared between the two polymerization methods Discuss the effects of the EB irradiation on the polymerization for having a good physical properties for the both hard and soft contact lens. EB irradiation can be used to the polymerization reaction and the EB polymerization take place at a very short period of time without any cross-linker and initiator and initiator above 100 kGy of EB dose. The polymer synthesized by EB irradiation can improve the physical properties of contact lens {yields} increase of the OH group on the surface by EB irradiation, resulting in increase o the water content and oxygen permeability of the contact lens The contact lens synthesized by EB irradiation could improve the physical properties of the contact lens, and specially can apply to a disposable soft contact lens with high water content and oxygen permeability.

  16. Analysis of Some Physio-Chemical Properties of Milk Bush (Thevetia peruviana Seeds

    Directory of Open Access Journals (Sweden)

    O.M. Olatunji

    2011-02-01

    Full Text Available The proximate and some technological properties of milk bush (Thevetia peruviana seeds were investigated. The results obtained showed the following chemical compositions: Moisture content (2.94%, protein (7.44%, oil (57.05%, crude fibre (22.37%, ash (2:24 and carbohydrate by difference (7.76%. In the same vain, mineralogical analysis using an inductively coupled plasma atomic emission spectrometer was conducted. The results obtained showed that magnesium, potassium and sodium were the predominant elements in the seeds. The technological properties studied were unit mass, unit volume, geometric mean, diameter, sphericity, bulk density, true density and porosity with average values of 4.14 g, 4.403.57 mm3, 20.34 mm, 0.67, 657.73 kg/m3, 942.05 kg/m3 and 31%, respectively. Information of these properties could be useful in process machine design. On the other hand, knowledge of the proximate properties is important for nutritional and dietary information.

  17. Chemical and rheological properties of exopolysaccharides produced by four isolates of rhizobia.

    Science.gov (United States)

    Moretto, Cristiane; Castellane, Tereza Cristina Luque; Lopes, Erica Mendes; Omori, Wellington Pine; Sacco, Laís Postai; Lemos, Eliana Gertrudes de Macedo

    2015-11-01

    The rheological, physicochemical properties, emulsification and stability of exopolysaccharides (EPSs) from four rhizobia isolates (LBMP-C01, LBMP-C02, LBMP-C03 and LBMP-C04) were studied. The EPS yields of isolates under these experimental conditions were in the range of 1.5-6.63gL(-1). The LBMP-C04 isolate, which presented the highest EPS production (6.63gL(-1)), was isolated from Arachis pintoi and was identified as a Rhizobium sp. strain that could be explored as a possible potential source for the production of extracellular heteropolysaccharides. All polymers showed a pseudoplastic non-Newtonian fluid behavior or shear thinning property in aqueous solutions. Among the four EPS tested against hydrocarbons, EPS LBMP-C01 was found to be more effective against hexane, olive and soybean oils (89.94%, 82.75% and 81.15%, respectively). Importantly, we found that changes in pH (2-11) and salinity (0-30%) influenced the emulsification of diesel oil by the EPSs. EPSLBMP-C04 presented optimal emulsification capacity at pH 10 (E24=53%) and 30% salinity (E24=27%). These findings contribute to the understanding of the influence of the chemical composition, physical properties and biotechnology applications of rhizobial EPS solutions their bioemulsifying properties. PMID:26234581

  18. The effect of chemical admixtures and mineral additives on the properties of self-compacting mortars

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa Sahmaran; Heru Ari Christianto; Ismail Ozgur Yaman [Middle East Technical University, Ankara (Turkey). Department of Civil Engineering

    2006-05-15

    Mortar serves as the basis for the workability properties of self-compacting concrete (SCC) and these properties could be assessed by self-compacting mortars (SCM). In fact, assessing the properties of SCM is an integral part of SCC design. The objective of this study was to evaluate the effectiveness of various mineral additives and chemical admixtures in producing SCMs. For this purpose, four mineral additives (fly ash, brick powder, limestone powder, and kaolinite), three superplasticizers (SP), and two viscosity modifying admixtures (VMA) were used. Within the scope of the experimental program, 43 mixtures of SCM were prepared keeping the amount of mixing water and total powder content (Portland cement and mineral additives) constant. Workability of the fresh mortar was determined using mini V-funnel and mini slump flow tests. The setting time of the mortars, were also determined. The hardened properties that were determined included ultrasonic pulse velocity and strength determined at 28 and 56 days. It was concluded that among the mineral additives used, fly ash and limestone powder significantly increased the workability of SCMs. On the other hand, especially fly ash significantly increased the setting time of the mortars, which can, however, be eliminated through the use of ternary mixtures, such as mixing fly ash with limestone powder. The two polycarboxyl based SPs yield approximately the same workability and the melamine formaldehyde based SP was not as effective as the other two.

  19. Impact of the post fire management in some soil chemical properties. First results.

    Science.gov (United States)

    Francos, Marcos; Pereira, Paulo; Alcañiz, Meritxell; Úbeda, Xavi

    2016-04-01

    Post-fire management after severe wildfires has impact on soil properties. In Mediterranean environments management of fire affected areas is a common practice. This intervention may change soil chemical properties of the soil such as major cations. The aim of this work is to study the impact of different types of forest management in soil extractable calcium, magnesium, sodium and potassium after a severe wildfire. The study area is located in Ódena (Catalonia, Spain). The wildfire occurred at July 27th of 2015 and burned 1235 ha. After the fire an experimental plot was designed 9 plots with 2x2 meters (4 square meters). The different managements were: a) clear-cuted area and wood removed, b) no treatment); and c) clear-cutted. The results of the first sampling showed significant differences among all treatments in extractable calcium, sodium and potassium. The amount of these extractable elements was high in clear-cutted treatment in comparison to the others. No differences were identified in extractable magnesium. Overall, in the immediate period after the fire, burned area management, changed the studied soil properties. We are currently studying the evolution of this soil properties in these plots with the time

  20. Investigation of chemical properties and transport phenomena associated with pollutants in the atmospheric boundary layer

    Science.gov (United States)

    Holmes, Heather A.

    Under the Clean Air Act, the U.S. Environmental Protection Agency is required to determine which air pollutants are harmful to human health, then regulate, monitor and establish criteria levels for these pollutants. To accomplish this and for scientific advancement, integration of knowledge from several disciplines is required including: engineering, atmospheric science, chemistry and public health. Recently, a shift has been made to establish interdisciplinary research groups to better understand the atmospheric processes that govern the transport of pollutants and chemical reactions of species in the atmospheric boundary layer (ABL). The primary reason for interdisciplinary collaboration is the need for atmospheric processes to be treated as a coupled system, and to design experiments that measure meteorological, chemical and physical variables simultaneously so forecasting models can be improved (i.e., meteorological and chemical process models). This dissertation focuses on integrating research disciplines to provide a more complete framework to study pollutants in the ABL. For example, chemical characterization of particulate matter (PM) and the physical processes governing PM distribution and mixing are combined to provide more comprehensive data for source apportionment. Data from three field experiments were utilized to study turbulence, meteorological and chemical parameters in the ABL. Two air quality field studies were conducted on the U.S./Mexico border. The first was located in Yuma, AZ to investigate the spatial and temporal variability of PM in an urban environment and relate chemical properties of ambient aerosols to physical findings. The second border air quality study was conducted in Nogales, Sonora, Mexico to investigate the relationship between indoor and outdoor air quality in order to better correlate cooking fuel types and home activities to elevated indoor PM concentrations. The final study was executed in southern Idaho and focused on

  1. Chemical Composition and Sensory and Pasting Properties of Blends of Maize-African Yam Bean Seed

    Directory of Open Access Journals (Sweden)

    Idowu Atinuke

    2015-07-01

    Full Text Available This study was designed to improve the nutritional content of maize flour by incorporating African yam bean (an underutilized crop with high nutritional value and to evaluate its effect on the chemical, sensory and pasting properties of the flour blends. Maize and African yam bean seed were processed into flours at ratios 100:0; 80:20; 70:30; 60:40 and 0:100 and used to produce tuwo, a maize-based meal, its sensory attributes being evaluated. Chemical and pasting properties of the flour blends were determined. Crude protein (9.61- 14.71%, crude fibre (1.34-5.81%, total ash (1.39-2.09% and sugar (4.11-6.01% contents increased while fat (4.53-3.94%, amylase (24.18-11.40%, starch (66.66-51.15% contents and some of the sensory qualities decreased significantly (p0.05 from control sample. Among the pasting parameters, final viscosity and break down viscosity reduced while peak viscosity and trough viscosity increased with increasing quantity of AYBF.

  2. Optical and structural properties of PbI2 thin film produced via chemical dipping method

    Science.gov (United States)

    Kariper, İ. A.

    2016-06-01

    PbI2 thin films were deposited on glass substrates via chemical bath deposition. The characteristics of PbI2 thin films were examined through their structural and optical properties. X-ray diffraction spectra showed the presence of rhombohedral structure and atom planes were subject to change with the pH of the bath. Scanning electron microscope indicated uniform distribution of grains. Optical properties were examined via UV-VIS; optical spectrum of the thin films was measured at the range of 200-1100 nm wavelength. Optimum pH levels for producing thin films were found to be pH 4-5. It has been observed that transmission and optical band gap ( E g) increased with the pH of the bath, which varied between 66-95 and 2.24-2.50 %, respectively; on the other hand film thickness of PbI2 thin films was decreased with the pH of the bath. Energy-dispersive X-ray spectroscopy analysis were in accordance with theoretical value of PbI2 at pH = 4 and 5. Refractive index was negatively correlated with pH of the chemical bath; it has been calculated as 1.97, 1.40, 1.29 and 1.24 for the films produced at pH 2, 3, 4 and 5. The results of the study were compared with similar studies in the literature.

  3. Chemically deposited TiO2/CdS bilayer system for photoelectrochemical properties

    Indian Academy of Sciences (India)

    P R Deshmukh; U M Patil; K V Gurav; S B Kulkarni; C D Lokhande

    2012-12-01

    In the present investigation, TiO2, CdS and TiO2/CdS bilayer system have been deposited on the fluorine doped tin oxide (FTO) coated glass substrate by chemical methods. Nanograined TiO2 was deposited on FTO coated glass substrates by successive ionic layers adsorption and reaction (SILAR) method. Chemical bath deposition (CBD)method was employed to deposit CdS thin film on pre-deposited TiO2 film. A further study has beenmade for structural, surface morphological, optical and photoelectrochemical (PEC) properties of FTO/TiO2, FTO/CdS and FTO/TiO2/CdS bilayers system. PEC behaviour of FTO/TiO2/CdS bilayers was studied and compared with FTO/CdS single system. FTO/TiO2/CdS bilayers system showed improved performance of PEC properties over individual FTO/CdS thin films.

  4. Improving N(6)-methyladenosine site prediction with heuristic selection of nucleotide physical-chemical properties.

    Science.gov (United States)

    Zhang, Ming; Sun, Jia-Wei; Liu, Zi; Ren, Ming-Wu; Shen, Hong-Bin; Yu, Dong-Jun

    2016-09-01

    N(6)-methyladenosine (m(6)A) is one of the most common and abundant post-transcriptional RNA modifications found in viruses and most eukaryotes. m(6)A plays an essential role in many vital biological processes to regulate gene expression. Because of its widespread distribution across the genomes, the identification of m(6)A sites from RNA sequences is of significant importance for better understanding the regulatory mechanism of m(6)A. Although progress has been achieved in m(6)A site prediction, challenges remain. This article aims to further improve the performance of m(6)A site prediction by introducing a new heuristic nucleotide physical-chemical property selection (HPCS) algorithm. The proposed HPCS algorithm can effectively extract an optimized subset of nucleotide physical-chemical properties under the prescribed feature representation for encoding an RNA sequence into a feature vector. We demonstrate the efficacy of the proposed HPCS algorithm under different feature representations, including pseudo dinucleotide composition (PseDNC), auto-covariance (AC), and cross-covariance (CC). Based on the proposed HPCS algorithm, we implemented an m(6)A site predictor, called M6A-HPCS, which is freely available at http://csbio.njust.edu.cn/bioinf/M6A-HPCS. Experimental results over rigorous jackknife tests on benchmark datasets demonstrated that the proposed M6A-HPCS achieves higher success rates and outperforms existing state-of-the-art sequence-based m(6)A site predictors. PMID:27293216

  5. Physical and chemical properties of Red MSX Sources in the southern sky: HII regions

    CERN Document Server

    Yu, Naiping; Li, Nan

    2016-01-01

    We have studied the physical and chemical properties of 18 southern Red Midcourse Space Experiment Sources (RMSs), using archival data taken from the Atacama Pathfinder Experiment (APEX) Telescope Large Area Survey of the Galaxy, the Australia Telescope Compact Array, and the Millimeter Astronomy Legacy Team Survey at 90 GHz. Most of our sources have simple cometary/unresolved radio emissions at 4.8 and/or 8.6GHz. The large number of Lyman continuum fluxes (NL) indicates they are probably massive O- or early B-type star formation regions. Archival IRAS infrared data are used to estimate the dust temperature, which is about 30 K of our sources. Then, the H2 column densities and the volume-averaged H2 number densities are estimated using the 0.87 mm dust emissions. Large-scale infall and ionized accretions may be occurring in G345.4881+00.3148. We also attempt to characterize the chemical properties of these RMSs through molecular line (N2H+ (1-0) and HCO+ (1-0)) observations. Most of the detected N2H+ and HCO+...

  6. Temperature effect on physical and chemical properties of secondary organic aerosol from m-xylene photooxidation

    Directory of Open Access Journals (Sweden)

    D. R. Cocker III

    2010-01-01

    Full Text Available The chemical and physical differences of secondary organic aerosol (SOA formed at select isothermal temperatures (278 K, 300 K, and 313 K are explored with respect to density, particle volatility, particle hygroscopicity, and elemental chemical composition. A transition point in SOA density, volatility, hygroscopicity and elemental composition is observed near 290–292 K as SOA within an environmental chamber is heated from 278 K to 313 K, indicating the presence of a thermally labile compound. No such transition points are observed for SOA produced at 313 K or 300 K and subsequently cooled to 278 K. The SOA formed at the lowest temperatures (278 K is more than double the SOA formed at 313 K. SOA formed at 278 K is less hydrophilic and oxygenated while more volatile and dense than SOA formed at 300 K or 313 K. The properties of SOA formed at 300 K and 313 K when reduced to 278 K did not match the properties of SOA initially formed at 278 K. This study demonstrates that it is insufficient to utilize the enthalpy of vaporization when predicting SOA temperature dependence.

  7. Nutritive Composition and Properties Physico-chemical of gumbo (Abelmoschus esculentus L. Seed and Oil

    Directory of Open Access Journals (Sweden)

    J.M. Nzikou

    2010-01-01

    Full Text Available Chemical and physical properties of mature gumbo (Abelmoschus esculentus L. seeds fromImpfondo, in North Congo-Brazzaville were evaluated. The chemical properties evaluated were moisture, crudeprotein, crude oil, crude ash, crude fiber, and crude energy. The oil from A.esculentus seeds was extracted usingtwo oils extraction methods with petroleum ether (Soxlhet and extraction with a mixture ofchloroform:methanol (1:1 (Blye and Dyer.The oil concentration ranged from 24.90% (Soxlhet to 21.98%(Blye & Dyer. The minerals, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters,unsaponifiable matter content, peroxide value, activation energy and differential scanning calorimetry w eredetermined. Abelmoschus esculentus L. seeds have ash content of 5.68% (with the presence of followingminerals: Ca, M g, K and N a. The oil was found to contain high levels of unsaturated fatty acids, especiallyoleic (up to 24.89% and linoleic (up to 42.78%. Abelmoschus esculentus L. oil can be classified in theoleic-linoleic acid group. The dominant saturated acid w as palmitic (up to 25.79%. Abelmoschus esculentusL. seeds were also founded to contain high levels of crude protein (24.85%. The content of insaponifiables is1.53%. Taking into account these results, the gumbo (Abelmoschus esculentus L. finds its applications in thefood and cosmetic industry.

  8. Comparison of Selected Soil Chemical Properties of Two Different Mangrove Forests in Sarawak

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    Empi Rambok

    2010-01-01

    Full Text Available Problem statement: Despite few studies of forest health and environmental conditions of mangrove forest in Sarawak, the data was not sufficient to facilitate baseline data and direct comparison of mangrove forest health obtained for different location of mangrove forest in Sarawak. On this regard, determination of contemporary mangrove soil condition was essential to addressing mangrove forest for forest health, carbon storage and environmental balance. The study attempts to obtained preliminary database of mangrove forest soil chemical properties and to compare the forest health from two different mangrove forest locations. Approach: Mangrove soil samples were taken from Miri and Limbang Division of Sarawak at 0-30 cm depth. Selected soil chemical properties were determined and data obtained were analyzed using Statistical Analysis System (SAS Version 9.2. Results: The soil acidity, total N, total P, CEC and humic acid of both locations were significantly different while in terms of total carbon and organic matter were similar. Conclusion: Regional diversity has significant effects the soil acidity, total N, total P, CEC and yield of the study areas. Data obtained can be useful for further study of carbon stock and nutrient content.

  9. ASSESSING THE CHEMICAL PROPERTIES OF DAMMAR ASPHALT USING FOURIER TRANSFORM INFRARED SPECTROSCOPY

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    Ary Setyawan

    2016-03-01

    Full Text Available Dammar Asphalt (Daspal is expected to be used as a bio-asphalt renewable binder for road construction. It is made with a modification of the "Jabung", which is the dammar gum based material mixed with grounded red brick debris and low quality cooking oil at a certain ratio. Dammar gum is obtained from the Dipterocarpaceae family of trees in India and East Asia, most are produced by tapping trees. The gum varies in color from clear to pale yellow. Dammar gum is a triterpenoid resin, containing a large number of triterpenes and their oxidation products. Many of them are low molecular weight compounds. The objective of this research is to analyze the chemical properties of Daspal uses a Resonance Fourier Transform Infrared Spectroscopy (FTIR method to compare with conventional asphalt. The investigation using spectral data showed that all types of Daspal have similar functional groups of Saturate, Aromatic, Resins, and Asphalten as the 60/70 penetration conventional bitumen, so that based on its chemical properties Daspal can be considered as bioaspal.

  10. Chemical Ordering Modulated Electronic Phase Separation and Macroscopic Properties in Colossal Magnetoresistance Manganites

    Science.gov (United States)

    Zhu, Yinyan; Du, Kai; Yin, Lifeng; Shen, Jian; Low-dimensional material physics Team

    Using unit cell by unit cell superlattice growth technique, we determine the role of chemical ordering of the Pr dopant in a colossal magnetoresistance (La1-yPry)1-x CaxMnO3 (LPCMO) system, which has been well known for its large length scale electronic phase separation (EPS) phenomena. Our experimental results show that the chemical ordering of Pr leads to dramatic reduction of the length scale of EPS. Moreover, compared to the conventional Pr-disordered LPCMO system, the Pr-ordered LPCMO system has ~100 K higher metal-insulator transition temperature. We have further investigated the n-dependence of the physical properties of the (LCMO)2n/(PCMO)n superlattices. Magnetic and transport measurements indicate that the physical properties change nonmonotonically with increasing n, reaching a minimum for both the Curie temperature and the meta-insulator transition temperature. The crossover thickness thus reflects the characteristic correlation length scale along the vertical direction of the superlattice. For superlattices with n smaller than the correlation length, we combine MFM studies and model calculations to explain the weakened ferromagnetism and metallicity with increasing n.

  11. Baryon chemical potential and in-medium properties of BPS skyrmions

    CERN Document Server

    Adam, C; Naya, C; Sanchez-Guillen, J; Vazquez, R; Wereszczynski, A

    2015-01-01

    We continue the investigation of thermodynamical properties of the BPS Skyrme model. In particular, we analytically compute the baryon chemical potential both in the full field theory and in a mean-field approximation. In the full field theory case, we find that the baryon chemical potential is always exactly proportional to the baryon density, for arbitrary solutions. We further find that, in the mean-field approximation, the BPS Skyrme model approaches the Walecka model in the limit of high density - their thermodynamical functions as well as the equation of state agree in this limit. This fact allows to read off some properties of the $\\omega$-meson from the BPS Skyrme action, even though the latter model is entirely based on the (pionic) $SU(2)$ Skyrme field. On the other hand, at low densities, at the order of the usual nuclear matter density, the equations of state of the two models are no longer universal, such that a comparison depends on some model details. Still, also the BPS Skyrme model gives rise...

  12. Hybrid density functional study on lattice vibration, thermodynamic properties, and chemical bonding of plutonium monocarbide

    Science.gov (United States)

    Rong, Yang; Bin, Tang; Tao, Gao; BingYun, Ao

    2016-06-01

    Hybrid density functional theory is employed to systematically investigate the structural, magnetic, vibrational, thermodynamic properties of plutonium monocarbide (PuC and PuC0.75). For comparison, the results obtained by DFT, DFT + U are also given. For PuC and PuC0.75, Fock-0.25 hybrid functional gives the best lattice constants and predicts the correct ground states of antiferromagnetic (AFM) structure. The calculated phonon spectra suggest that PuC and PuC0.75 are dynamically stable. Values of the Helmholtz free energy ΔF, internal energy ΔE, entropy S, and constant-volume specific heat C v of PuC and PuC0.75 are given. The results are in good agreement with available experimental or theoretical data. As for the chemical bonding nature, the difference charge densities, the partial densities of states and the Bader charge analysis suggest that the Pu-C bonds of PuC and PuC0.75 have a mixture of covalent character and ionic character. The effect of carbon vacancy on the chemical bonding is also discussed in detail. We expect that our study can provide some useful reference for further experimental research on the phonon density of states, thermodynamic properties of the plutonium monocarbide. Project supported by the National Natural Science Foundation of China (Grant Nos. 21371160 and 21401173).

  13. Evaluation of the Chemical and Mechanical Properties of Hardening High-Calcium Fly Ash Blended Concrete

    Directory of Open Access Journals (Sweden)

    Wei-Jie Fan

    2015-09-01

    Full Text Available High-calcium fly ash (FH is the combustion residue from electric power plants burning lignite or sub-bituminous coal. As a mineral admixture, FH can be used to produce high-strength concrete and high-performance concrete. The development of chemical and mechanical properties is a crucial factor for appropriately using FH in the concrete industry. To achieve sustainable development in the concrete industry, this paper presents a theoretical model to systematically evaluate the property developments of FH blended concrete. The proposed model analyzes the cement hydration, the reaction of free CaO in FH, and the reaction of phases in FH other than free CaO. The mutual interactions among cement hydration, the reaction of free CaO in FH, and the reaction of other phases in FH are also considered through the calcium hydroxide contents and the capillary water contents. Using the hydration degree of cement, the reaction degree of free CaO in FH, and the reaction degree of other phases in FH, the proposed model evaluates the calcium hydroxide contents, the reaction degree of FH, chemically bound water, porosity, and the compressive strength of hardening concrete with different water to binder ratios and FH replacement ratios. The evaluated results are compared to experimental results, and good consistencies are found.

  14. Evaluation of the Chemical and Antioxidant Properties of Wild and Cultivated Mushrooms of Ghana

    Directory of Open Access Journals (Sweden)

    Mary Obodai

    2014-11-01

    Full Text Available Knowledge of the chemical composition of both wild and cultivated edible mushrooms in Ghana is limited. This study reports their nutritional value, composition in lipophilic and hydrophilic molecules, minerals and antioxidant properties. The samples were found to be nutritionally rich in carbohydrates, ranging from 64.14 ± 0.93 g in Pleurotus ostreatus strain EM-1 to 80.17 ± 0.34 g in Lentinus squarrosulus strain LSF. The highest level of proteins (28.40 ± 0.86 g was recorded in the mentioned P. ostreatus strain. Low fat contents were registered in the samples, with Auricularia auricula recording the lowest value. High levels of potassium were also observed with the following decreasing order of elements: K > P ~ Na > Mg > Ca. High levels of antioxidants were also observed, thus making mushrooms suitable to be used as functional foods or nutraceutical sources. Furthermore, this study provides new information regarding chemical properties of mushrooms from Ghana, which is very important for the biodiversity characterization of this country.

  15. Chemical linkage to injected tissues is a distinctive property of oxidized avidin.

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    Rita De Santis

    Full Text Available We recently reported that the oxidized avidin, named AvidinOX®, resides for weeks within injected tissues as a consequence of the formation of Schiff's bases between its aldehyde groups and tissue protein amino groups. We also showed, in a mouse pre-clinical model, the usefulness of AvidinOX for the delivery of radiolabeled biotin to inoperable tumors. Taking into account that AvidinOX is the first oxidized glycoprotein known to chemically link to injected tissues, we tested in the mouse a panel of additional oxidized glycoproteins, with the aim of investigating the phenomenon. We produced oxidized ovalbumin and mannosylated streptavidin which share with avidin glycosylation pattern and tetrameric structure, respectively and found that neither of them linked significantly to cells in vitro nor to injected tissues in vivo, despite the presence of functional aldehyde groups. The study, extended to additional oxidized glycoproteins, showed that the in vivo chemical conjugation is a distinctive property of the oxidized avidin. Relevance of the high cationic charge of avidin into the stable linkage of AvidinOX to tissues is demonstrated as the oxidized acetylated avidin lost the property. Plasmon resonance on matrix proteins and cellular impedance analyses showed in vitro that avidin exhibits a peculiar interaction with proteins and cells that allows the formation of highly stable Schiff's bases, after oxidation.

  16. Physico-chemical and Antioxidant Properties of Different Pumpkin Cultivars Grown in China

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2015-08-01

    Full Text Available To obtain more detailed knowledge of the differences among major pumpkin species grown in China, physico-chemical and antioxidant properties of four pumpkin cultivars (Miben, Hongli, Lvli, Xihulu were characterized and compared. Dry matter, total soluble solids, titratable acidity, fruit color, protein, fat, sugars, minerals, amino acids, &beta -carotene, L-ascorbic acid, total phenols and antioxidant activities (DPPH and FRAP were measured in the studied cultivars. The results showed great differences in the composition and characteristics of the pumpkin cultivars. Miben exhibited the highest concentration of dry matter, fat, Total Soluble Solid (TSS, Titratable Acidity (TA, sucrose, &beta-carotene, K, P, Fe, Zn and aspartic acid. Hongli had the highest concentration protein, L-ascorbic acid, Na, Ca, Mg and all individual amino acids except for asparitic acid. Lvli exhibited significantly (p<0.05 higher antioxidant activities (DPPH and FRAP, which are highly related to total phenols content in pumpkin fruits (r = 0.94 and r = 0.98, respectively. Principal Component Analysis (PCA allowed the four pumpkin cultivars to be differentiated clearly based on all these physico-chemical and antioxidant properties determined in the study.

  17. Physical and Chemical Properties of Sediments in Huainan Segment of Huaihe River

    Institute of Scientific and Technical Information of China (English)

    CHENG Yong-hong; XU Jun; WANG Juan; TIAN Dong; CHEN Jun; GAO Zhi-kang

    2005-01-01

    The chemical and physical properties of nitrogen and phosphorus as well as their concentrations in the overlying water, pore-water and sediments in Huainan segment of the Huaihe river were analyzed. The chemical forms of phosphorus in sediments were differentiated by a sequential fraction method. The results revealed that the NH4+-N content in pore-water of 6 surface sediments is obviously higher than that in overlying water, indicating that there is a dynamic tendency of releasing NH4+-N from sediment into overlying water. Chemical compound of nitrogen differs among segments of the river, while phosphorus has no such difference. Calcium bound phosphate (Ca-P) and iron bound phosphate (Fe-P) accounts for 60 % of the total phosphorus, and occluded-P (O-P) accounts for less than 20 %. Our findings indicate that 1) industrial waste water and domestic sewage have contributed to the excessive nutrient salts in Huaihe river, 2) decreased water flow during low water periods, and the interaction between sediments and overlying water disturbed by transport ships accelerate nutrient salt releasing into overlying water, which results in eutrophication of the river.

  18. The effect of wash cleaning and demagnetization process on the fly ash physico-chemical properties

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    A. Baliński

    2007-04-01

    Full Text Available Problems related in this study concern the possibility of improving the physico-chemical properties of fly ash used as a base granular material in moulding mixtures. The investigations were carried out mainly to evaluate the process of the fly ash modification performed in order to stabilize its mineralogical and chemical composition. Changes in chemical composition, specific surface and helium density of fly ash after the process of its wash cleaning and demagnetization were examined. The analysis of the data has proved that the process of wash cleaning considerably reduces the content of sodium and potassium. Calcium and magnesium are washed out, too. The wash cleaning process of fly ash reduces also its true density. This fact can be due to the washing out of illite as well as some fractions of haematite (the grains weakly bonded to the glassy phase. The process of demagnetization allows removing about 25.7% of the magnetic phase calculated in terms of Fe2O3. The process of demagnetization is accompanied by a decrease in the content of aluminium, sodium, potassium and calcium, and a reduction in the size of the specific surface by over one half. The possible processes of transformation have also been discussed.

  19. Composition and Physico-Chemical Properties of Meat from Capons Fed Cereals

    Institute of Scientific and Technical Information of China (English)

    Olga Díaz; Luisana Rodríguez; Alexandr Torres; Ángel Cobos

    2013-01-01

    Chemical composition, physico-chemical properties and fatty acid composition of breast and drumstick meat from capons (castrated male cockerels) fed cereals were studied. Three groups of capons were reared. One group was fed ad libitum the same commercial diet until the 4th mon of life. The last month of its life, the capons of this group were fed corn. The second and third group of capons were fed the same diet from caponization. The second group was fed mixture of corn (50%) and wheat (50%). The third group of capons was fed 2/3 corn and 1/3 mixture of corn (50%) and barley (50%). Capons were reared under free-range conditions and slaughtered at 150 d of age. Caponization was performed at 48 d. No signiifcant effects of feeding in chemical composition, pH, water holding capacity, drip and cooking losses and texture of the meat were observed. The meat of the third group (capons fed 83%corn) was more yellow and showed higher content of C18:2 than that of the other capons.

  20. Chemically cross-linked silk fibroin hydrogel with enhanced elastic properties, biodegradability, and biocompatibility

    Directory of Open Access Journals (Sweden)

    Kim MH

    2016-06-01

    Full Text Available Min Hee Kim, Won Ho Park Department of Advanced Organic Materials and Textile Engineering System, Chungnam National University, Daejeon, Korea Abstract: In this study, the synthesis of silk fibroin (SF hydrogel via chemical cross-linking reactions of SF due to gamma-ray (γ-ray irradiation was investigated, as were the resultant hydrogel’s properties. Two different hydrogels were investigated: physically cross-linked SF hydrogel and chemically cross-linked SF hydrogel irradiated at different doses of γ-rays. The effects of the irradiation dose and SF concentration on the hydrogelation of SF were examined. The chemically cross-linked SF hydrogel was compared with the physically cross-linked one with regard to secondary structure and gel strength. Furthermore, the swelling behavior, crystallinity, and biodegradation of the SF hydrogels were characterized. To assay cell proliferation, the cell viability of human mesenchymal stem cells on the lyophilized SF hydrogel scaffolds was evaluated, and no significant cytotoxicity against human mesenchymal stem cells was observed. Keywords: silk fibroin, hydrogels, biodegradation rate, gamma irradiation, cross-linking

  1. Estimation of environment-related properties of chemicals for design of sustainable processes: development of group-contribution+ (GC+) property models and uncertainty analysis.

    Science.gov (United States)

    Hukkerikar, Amol Shivajirao; Kalakul, Sawitree; Sarup, Bent; Young, Douglas M; Sin, Gürkan; Gani, Rafiqul

    2012-11-26

    The aim of this work is to develop group-contribution(+) (GC(+)) method (combined group-contribution (GC) method and atom connectivity index (CI) method) based property models to provide reliable estimations of environment-related properties of organic chemicals together with uncertainties of estimated property values. For this purpose, a systematic methodology for property modeling and uncertainty analysis is used. The methodology includes a parameter estimation step to determine parameters of property models and an uncertainty analysis step to establish statistical information about the quality of parameter estimation, such as the parameter covariance, the standard errors in predicted properties, and the confidence intervals. For parameter estimation, large data sets of experimentally measured property values of a wide range of chemicals (hydrocarbons, oxygenated chemicals, nitrogenated chemicals, poly functional chemicals, etc.) taken from the database of the US Environmental Protection Agency (EPA) and from the database of USEtox is used. For property modeling and uncertainty analysis, the Marrero and Gani GC method and atom connectivity index method have been considered. In total, 22 environment-related properties, which include the fathead minnow 96-h LC(50), Daphnia magna 48-h LC(50), oral rat LD(50), aqueous solubility, bioconcentration factor, permissible exposure limit (OSHA-TWA), photochemical oxidation potential, global warming potential, ozone depletion potential, acidification potential, emission to urban air (carcinogenic and noncarcinogenic), emission to continental rural air (carcinogenic and noncarcinogenic), emission to continental fresh water (carcinogenic and noncarcinogenic), emission to continental seawater (carcinogenic and noncarcinogenic), emission to continental natural soil (carcinogenic and noncarcinogenic), and emission to continental agricultural soil (carcinogenic and noncarcinogenic) have been modeled and analyzed. The application

  2. Estimation of environment-related properties of chemicals for design of sustainable processes: development of group-contribution+ (GC+) property models and uncertainty analysis.

    Science.gov (United States)

    Hukkerikar, Amol Shivajirao; Kalakul, Sawitree; Sarup, Bent; Young, Douglas M; Sin, Gürkan; Gani, Rafiqul

    2012-11-26

    The aim of this work is to develop group-contribution(+) (GC(+)) method (combined group-contribution (GC) method and atom connectivity index (CI) method) based property models to provide reliable estimations of environment-related properties of organic chemicals together with uncertainties of estimated property values. For this purpose, a systematic methodology for property modeling and uncertainty analysis is used. The methodology includes a parameter estimation step to determine parameters of property models and an uncertainty analysis step to establish statistical information about the quality of parameter estimation, such as the parameter covariance, the standard errors in predicted properties, and the confidence intervals. For parameter estimation, large data sets of experimentally measured property values of a wide range of chemicals (hydrocarbons, oxygenated chemicals, nitrogenated chemicals, poly functional chemicals, etc.) taken from the database of the US Environmental Protection Agency (EPA) and from the database of USEtox is used. For property modeling and uncertainty analysis, the Marrero and Gani GC method and atom connectivity index method have been considered. In total, 22 environment-related properties, which include the fathead minnow 96-h LC(50), Daphnia magna 48-h LC(50), oral rat LD(50), aqueous solubility, bioconcentration factor, permissible exposure limit (OSHA-TWA), photochemical oxidation potential, global warming potential, ozone depletion potential, acidification potential, emission to urban air (carcinogenic and noncarcinogenic), emission to continental rural air (carcinogenic and noncarcinogenic), emission to continental fresh water (carcinogenic and noncarcinogenic), emission to continental seawater (carcinogenic and noncarcinogenic), emission to continental natural soil (carcinogenic and noncarcinogenic), and emission to continental agricultural soil (carcinogenic and noncarcinogenic) have been modeled and analyzed. The application

  3. Impact of Sulfuric Acid Treatment of Halloysite on Physico-Chemic Property Modification

    Directory of Open Access Journals (Sweden)

    Tayser Sumer Gaaz

    2016-07-01

    Full Text Available Halloysite (HNT is treated with sulfuric acid and the physico-chemical properties of its morphology, surface activity, physical and chemical properties have been investigated when HNT is exposed to sulfuric acid with treatment periods of 1 h (H1, 3 h (H3, 8 h (H8, and 21 h (H21. The significance of this and similar work lies in the importance of using HNT as a functional material in nanocomposites. The chemical structure was characterized by Fourier transform infrared spectroscopy (FTIR. The spectrum demonstrates that the hydroxyl groups were active for grafting modification using sulfuric acid, promoting a promising potential use for halloysite in ceramic applications as filler for novel clay-polymer nanocomposites. From the X-ray diffraction (XRD spectrum, it can be seen that the sulfuric acid breaks down the HNT crystal structure and alters it into amorphous silica. In addition, the FESEM images reveal that the sulfuric acid treatment dissolves the AlO6 octahedral layers and induces the disintegration of SiO4 tetrahedral layers, resulting in porous nanorods. The Bruncher-Emmett-Teller (BET surface area and total pore volume of HNTs showed an increase. The reaction of the acid with both the outer and inner surfaces of the nanotubes causes the AlO6 octahedral layers to dissolve, which leads to the breakdown and collapse of the tetrahedral layers of SiO4. The multi-fold results presented in this paper serve as a guide for further HNT functional treatment for producing new and advanced nanocomposites.

  4. Effect of Organic Fertilizers on Soil Chemical Properties on Vineyard Calcareous Soil

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    Tomislav Karažija

    2015-12-01

    Full Text Available Organic fertilizers are an important contribution of organic matter that modify the physical, chemical and microbiological characteristics of the soil. The aim of investigation was to determine the effect of different organic fertilization on soil chemical properties on vineyard calcareous soil. Two-year fertilization trial was carried out in the Plešivica wine-growing region, in a 10-year old vineyard, cv. Sauvignon White grafted on Kobber 5BB rootstock, planted on soil with quite high pH for grapevine growing. The trial was performed according to randomize complete block design with 6 treatments (unfertilized, farmyard manure 20 t ha-1 and 40 t ha-1, peat 20 000 L ha-1 and 40 000 L ha-1, NPK 5-20-30 500 kg ha-1+200 kg UREA ha-1 in 4 repetitions. Statistically significant differences in soil reaction (pH in plowing layer (0-30 cm were found among fertilization treatments in the second year of studies. In the plowing layer (0-30 cm in both years of the study significant differences between the values of average total nitrogen content and available phosphorus as well were found, while there were no significant differences in the subplowing layer (30-60cm. Regarding to average value of fertilization treatment, statistically significant difference in the content of available potassium in plowing layer were found in the both investigated years, while in subplowing layer statistical differences were found in the first year of investigation only. Therefore, fertilization with different organic fertilizers significantly influenced the most of studied chemical properties of the soil, especially in plowing layer (0-30 cm.

  5. Cassava Peels for Alternative Fibre in Pulp and Paper Industry: Chemical Properties and Morphology Characterization

    Directory of Open Access Journals (Sweden)

    Ashuvila Mohd Aripin

    2013-11-01

    Full Text Available Without a proper waste management, the organic wastes such as cassava peels could result in increased amount of solid waste dump into landfill. This study aims to use non-wood organic wastes as pulp for paper making industries; promoting the concept of ‘from waste to wealth and recyclable material’. The objective  of this study is to determine the potential of casssava peel as alternative fibre in pulp and paper based on its chemical properties and surface morphology characteristic. Quantified parameters involved are holocellulose, cellulose, hemicellulose, lignin, one percent of sodium hydroxide, hot water solubility and ash content. The chemical characterization was in accordance with relevant TAPPI Test, Kurscher-Hoffner and Chlorite methods. Scanning electron microscopy (SEM was used to observe and determine the morphological characteristic of untreated cassava peels fibre. In order to propose the suitability of the studied plant as an alternative fibre resource in pulp and paper making, the obtained results are compared to other published literatures especially from wood sources. Results indicated that the amount of holocellulose contents in cassava peels (66% is the lowest than of wood (70 - 80.5% and canola straw (77.5%; however this value is still within the limit suitability to produce paper. The lignin content (7.52% is the lowest than those of all wood species (19.9-26.22%. Finally, the SEM images showed that untreated cassava peel contains abundance fibre such as hemicellulose and cellulose that is hold by the lignin in it. In conclusion, chemical properties and morphological characteristics of cassava peel indicated that it is suitable to be used as an alternative fibre sources for pulp and paper making industry, especially in countries with limited wood resources

  6. Modelling the optical properties of aerosols in a chemical transport model

    Science.gov (United States)

    Andersson, E.; Kahnert, M.

    2015-12-01

    According to the IPCC fifth assessment report (2013), clouds and aerosols still contribute to the largest uncertainty when estimating and interpreting changes to the Earth's energy budget. Therefore, understanding the interaction between radiation and aerosols is both crucial for remote sensing observations and modelling the climate forcing arising from aerosols. Carbon particles are the largest contributor to the aerosol absorption of solar radiation, thereby enhancing the warming of the planet. Modelling the radiative properties of carbon particles is a hard task and involves many uncertainties arising from the difficulties of accounting for the morphologies and heterogeneous chemical composition of the particles. This study aims to compare two ways of modelling the optical properties of aerosols simulated by a chemical transport model. The first method models particle optical properties as homogeneous spheres and are externally mixed. This is a simple model that is particularly easy to use in data assimilation methods, since the optics model is linear. The second method involves a core-shell internal mixture of soot, where sulphate, nitrate, ammonia, organic carbon, sea salt, and water are contained in the shell. However, by contrast to previously used core-shell models, only part of the carbon is concentrated in the core, while the remaining part is homogeneously mixed with the shell. The chemical transport model (CTM) simulations are done regionally over Europe with the Multiple-scale Atmospheric Transport and CHemistry (MATCH) model, developed by the Swedish Meteorological and Hydrological Institute (SMHI). The MATCH model was run with both an aerosol dynamics module, called SALSA, and with a regular "bulk" approach, i.e., a mass transport model without aerosol dynamics. Two events from 2007 are used in the analysis, one with high (22/12-2007) and one with low (22/6-2007) levels of elemental carbon (EC) over Europe. The results of the study help to assess the

  7. Investigation of chemical and physical properties of carbon nanotubes and their effects on cell biomechanics

    Science.gov (United States)

    Dong, Chenbo

    Carbon nanotubes (CNTs) are used for a variety of applications from nanocircuits, to hydrogen storage devices, and from designing optical fibers to forming conductive plastics. Recently, their functionalization with biomolecules led to exciting biological and biomedical applications in drug delivery or bioimaging. However, because of CNTs interactions with biological systems and their ability to translocate and persist into the circulatory and lymphatic systems and biological tissues, concerns about CNTs intrinsic toxicity have risen. It is thus necessary to develop and implement sensitive analysis technologies that allow investigation of CNTs toxicity upon uptake into a biological system. This thesis provides a comprehensive guide of experiments that have been performed during my Ph.D. tenure at West Virginia University in the Department of Chemical Engineering, in the group of Prof. Cerasela Zoica Dinu. Briefly: Chapter one presents a systematic study of the CNTs physical and chemical properties and how these properties are changed upon exposure to chemical agents normally used during their cleaning and purification processes. Also, this chapter shows how acid oxidation treatment leads to improved CNTs biocompatibility. Specifically, by incubating CNTs in a strong acid mixture we created a user-defined library of CNTs samples with different characteristics as recorded using Raman energy dispersive x-ray spectroscopy, atomic force microscopy, or solubility tests. Systematically characterized CNTs were subsequently tested for their biocompatibility in relation to human epithelial cells or enzymes. Such selected examples are building pertinent relationships between CNTs biocompatibility and their intrinsic properties by showing that acid oxidation treatment lowers CNTs toxicity making CNTs feasible platforms to be used for biomedical applications or the next generation of biosensors. (Publication: Chenbo Dong, Alan S Campell, Reem Eldawud, Gabriela Perhinschi, and

  8. ALTERNATIVE BINDERS TO BENTONITE FOR IRON ORE PELLETIZING : PART II : EFFECTS ON METALLURGICAL AND CHEMICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Osman Sivrikaya

    2014-07-01

    Full Text Available This study was started to find alternative binders to bentonite and to recover the low preheated and fired pellet mechanical strengths of organic binders-bonded pellets. Bentonite is considered as a chemical impurity for pellet chemistry due to acid constituents (SiO2 and Al2O3. Especially addition of silica-alumina bearing binders is detrimental for iron ore concentrate with high acidic content. Organic binders are the most studied binders since they are free in silica. Although they yield pellets with good wet strength; they have found limited application in industry since they fail to give sufficient physical and mechanical strength to preheated and fired pellets. It is investigated that how insufficient preheated and fired pellet strengths can be improved when organic binders are used as binder. The addition of a slag bonding/strength increasing constituent (free in acidic contents into pellet feed to provide pellet strength with the use of organic binders was proposed. Addition of boron compounds such as colemanite, tincal, borax pentahydrate, boric acid together with organic binders such as CMC, starch, dextrin and some organic based binders, into magnetite and hematite pellet mixture was tested. After determining the addition of boron compounds is beneficial to recover the low pellet physical and mechanical qualities in the first part of this study, in this second part, metallurgical and chemical properties (reducibility - swelling index – microstructure – mineralogy - chemical content of pellets produced with combined binders (an organic binder plus a boron compound were presented. The metallurgical and chemical tests results showed that good quality product pellets can be produced with combined binders when compared with the bentonite-bonded pellets. Hence, the suggested combined binders can be used as binder in place of bentonite in iron ore pelletizing without compromising the pellet chemistry.

  9. Impacts of land use changes on physical and chemical soil properties in the Central Pyrenees

    Science.gov (United States)

    Nadal Romero, Estela; Hoitinga, Leo; Valdivielso, Sergio; Pérez Cardiel, Estela; Serrano Muela, Pili; Lasanta, Teodoro; Cammeraat, Erik

    2015-04-01

    Soils and vegetation tend to evolve jointly in relation to climate evolution and the impacts of human activity. Afforestation has been one of the main policies for environmental management of forest landscapes in Mediterranean areas. Afforestation has been based mainly on conifers because they are fast-growing species, and also because it was believed that this would lead to rapid restoration of soil properties and hydrological processes, and the formation of protective vegetation cover. This study analyses the effects of afforestation on physical and chemical soil properties. Specifically, we addressed this research question: (i) How do soil properties change after land abandonment? The 11 microsites considered were: Afforestation Pinus sylvestris (escarpment, terrace and close to the stem), Afforestation Pinus nigra (escarpment, terrace and close to the stem), natural shrubland, grasslands, bare lands, and undisturbed forest site (pine cover and close to the stem). An extensive single sampling was carried out in September 2014. We systematically collected 5 top soil samples (0-10 cm) and 3 deep soil samples (10-20 cm) per microsite (88 composite samples in total). These properties were analysed: (i) soil texture, (ii) bulk density, (iii) pH and electrical conductivity, (iv) total SOC, (v) Total Nitrogen, (vi) organic matter, (vii) CaCO3 and (viii) aggregate stability. Statistical tests have been applied to determine relationships between the different soil properties and are used to assess differences between different soil samples, land use areas and soil depths. Implications of reafforestation for soil development and environmental response are discussed. Acknowledgments This research was supported by a Marie Curie Intra-European Fellowship in the project "MED-AFFOREST" (PIEF-GA-2013-624974).

  10. Resolving Changing Chemical and Physical Properties of SSA Particle Types during Laboratory Phytoplankton Blooms using Online Single Particle Analysis

    Science.gov (United States)

    Sultana, C. M.; Prather, K. A.; Richardson, R.; Wang, X.

    2015-12-01

    Changes in the chemical composition of sea spray aerosols (SSA) can modify their climate-relevant properties. Recent studies have shown a diverse set of distinct SSA particle types, however there are conflicting reports on how and whether biological activity controls the organic fraction and mixing state of SSA. This study leverages an aerosol time-of-flight mass spectrometer to give an accounting of the temporally resolved mixing state of primary SSA (0.4 - 3 µm vacuum aerodynamic diameter), encompassing 97% of particles detected over the course of laboratory phytoplankton blooms. The influence of biological activity on the climate relevant properties of defined particle types is also investigated. Spatial chemical particle heterogeneity and particularly the surface chemical composition of particles are described along with particle type specific water-particle interactions. These online measurements in tandem with chemical composition could give new insight on the link between seawater chemistry, marine aerosols, and climate properties.

  11. Tree species traits influence soil physical, chemical, and biological properties in high elevation forests.

    Directory of Open Access Journals (Sweden)

    Edward Ayres

    Full Text Available BACKGROUND: Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. METHODOLOGY/PRINCIPAL FINDINGS: We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the tree species, with the highest nitrogen (N concentration and lowest lignin:N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin:N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among tree species, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid

  12. Influence of chemical treatment on the tensile properties of kenaf fiber reinforced thermoplastic polyurethane composite

    Directory of Open Access Journals (Sweden)

    Y. A. El-Shekeil

    2012-12-01

    Full Text Available In this study, the effect of polymeric Methylene Diphenyl Diisocyanate (pMDI chemical treatment on kenaf (Hibiscus cannabinus reinforced thermoplastic polyurethane (TPU/KF was examined using two different procedures. The first consisted of treating the fibers with 4% pMDI, and the second involved 2% NaOH + 4% pMDI. The composites were characterized according to their tensile properties, Fourier Transform Infrared Spectroscopy (FTIR and Scanning Electron Microscopy (SEM. The treatment of the composite with 4% pMDI did not significantly affect its tensile properties, but the treatment with 2% NaOH + 4% pMDI significantly increased the tensile properties of the composite (i.e., 30 and 42% increases in the tensile strength and modulus, respectively. FTIR also showed that treatment with 2% NaOH + 4% pMDI led to the strongest H-bonding. Additionally, the surface morphology of specimens after tensile fracture confirmed that the composite treated with 2% NaOH + 4% pMDI had the best adhesion and wettability.

  13. The optical properties and chemical composition of Po Valley fog water

    Science.gov (United States)

    Jahl, L.; Hawkins, L. N.; Gilardoni, S.

    2013-12-01

    The chemical composition and solar radiation absorption properties of fog water are important because of the effects these properties can have on the climate. Fog samples contain compounds that may absorb light, and this radiative forcing may be significant. The Po Valley, located between the Apennine and Alps mountain ranges in Italy, has a high occurrence of fog events, which can be up to 30% of the time in the winter season. Absorption spectra of fog water samples from San Pietro Capofiume, Italy were taken in a Liquid Waveguide Capillary Cell with a UV-visible spectrophotometer. Spectra were fitted and absorptions at different wavelengths were correlated to the organic carbon and organic nitrogen concentrations of the samples. Ion chromatography was also used to obtain the concentrations of several ions such as nitrite, nitrate, sulfate, acetate, ammonium, and various amines. A correlation was found between absorbance and organic carbon content, as well as between absorbance at less than 300 nm wavelengths and organic nitrogen content. Characteristic absorptivities at 365 nm were calculated from Beer's law with regard to the organic carbon content and revealed similar results to those calculated from Los Angeles fog water samples earlier this year. The absorption angstrom exponents of the samples imply that the likely source of the optically active species is from biomass burning, and this will later be confirmed by a tracer analysis. High organic nitrogen : organic carbon ratios in all samples suggest that compounds containing nitrogen have a large contribution to the light absorbing properties of fog water.

  14. Influence of the Chemical Composition on Electrical Conductivity and Mechanical Properties of the Hypoeutectic Al-Si-Mg Alloys

    OpenAIRE

    Dybowski B.; Szymszal J.; Poloczek Ł.; Kiełbus A.

    2016-01-01

    Due to low density and good mechanical properties, aluminium alloys are widely applied in transportation industry. Moreover, they are characterized by the specific physical properties, such as high electrical conductivity. This led to application of the hypoeutectic Al-Si-Mg alloys in the power generation industry. Proper selection of the alloys chemical composition is an important stage in achievement of the demanded properties. The following paper presents results of the research on the inf...

  15. Marine Primary Aerosol in the Mediterranean atmosphere: physical and chemical properties from a mesocosm study

    Science.gov (United States)

    D'anna, B.; Sellegri, K.; Charriere, B.; Sempere, R.; Mas, S.; George, C.; Meme, A.; R'Mili, B.; Schwier, A. N.; Rose, C.

    2013-12-01

    The Mediterranean Sea is a special marine environment characterized by low biological activity and high anthropogenic pressure. It is often difficult to discriminated the contribution of Primary Sea Salt Aerosol (SSA) formed at the sea-air interface from background level of the aerosol. An alternative tool to study the sea-air exchanges in a controlled environment is provided by the mesocosms, which represent an important link between field studies and laboratory experiments. A mesocosms experiment was performed in May 2013 at the Oceanographic and Marine Station STARESO in Western Corsica. Three mesocosms were simultaneously filled with pooled and screened (water column depth of 2 m and contained 2260 L of Bay water and covered with transparent (teflon film) dome to prevent atmospheric contamination. The three mesocosms were equipped with a pack of optical and physicochemical sensors and received different treatements: one was left unchanged as control and two were enriched by addition of nitrates and phosphates respecting Redfield ration (N:P = 16). The evolution of the three systems was followed for 20 days. A set of sensors in each mesocosm were established at 0.5 m and allowed to monitor at high frequency (every 2 min): water temperature, conductivity, pH, incident light, fluorescence of chlorophyll a and dissolved oxygen concentration. The mesocosms waters were daily sampled for chemical (dissolved oxygen, colored dissolved organic matter, nitrates, phosphates, silicates, transparent polyssacharides, dicarboxylic acids and related polar compounds) and biological (chlorophyll a, virus, phytoplankton and zooplankton concentration) analyses. Finally, few liters of sea-water from each mesocosms were sampled daily and immediately transferred to a bubble-bursting apparatus to simulate SSA. Size distribution and particle number were followed by SMPS and APS in the range of 10nm to 10μm. The hygroscopic properties were investigated by a CCN device. On-line chemical

  16. Physical and chemical properties of ice residuals during the 2013 and 2014 CLACE campaigns

    Science.gov (United States)

    Kupiszewski, Piotr; Weingartner, Ernest; Vochezer, Paul; Hammer, Emanuel; Gysel, Martin; Färber, Raphael; Fuchs, Claudia; Schnaiter, Martin; Baltensperger, Urs; Schmidt, Susan; Schneider, Johannes; Bigi, Alessandro; Toprak, Emre; Linke, Claudia; Klimach, Thomas

    2014-05-01

    The shortcomings in our understanding and, thus, representation of aerosol-cloud interactions are one of the major sources of uncertainty in climate model projections. Among the poorly understood processes is mixed-phase cloud formation via heterogeneous nucleation, and the subsequent spatial and temporal evolution of such clouds. Cloud glaciation augments precipitation formation, resulting in decreased cloud cover and lifetime, and affects cloud radiative properties. Meanwhile, the physical and chemical properties of atmospherically relevant ice nuclei (IN), the sub-population of aerosol particles which enable heterogeneous nucleation, are not well known. Extraction of ice residuals (IR) in mixed-phase clouds is a difficult task, requiring separation of the few small, freshly formed ice crystals (the IR within such crystals can be deemed representative of the original IN) not only from interstitial particles, but also from the numerous supercooled droplets which have aerodynamic diameters similar to those of the ice crystals. In order to address the difficulties with ice crystal sampling and IR extraction in mixed-phase clouds, the new Ice Selective Inlet (ISI) has been designed and deployed at the Jungfraujoch field site. Small ice crystals are selectively sampled via the inlet with simultaneous counting, sizing and imaging of hydrometeors contained in the cloud by a set of optical particle spectrometers, namely Welas optical particle counters (OPC) and a Particle Phase Discriminator (PPD). The heart of the ISI is a droplet evaporation unit with ice-covered inner walls, resulting in removal of droplets using the Wegener-Bergeron-Findeisen process, while transmitting a relatively high fraction of small ice crystals. The ISI was deployed in the winters of 2013 and 2014 at the high alpine Jungfraujoch site (3580 m.a.s.l) during the intensive CLACE field campaigns. The measurements focused on analysis of the physical and chemical characteristics of IR and the

  17. Minimum quantity of urban refuse compost affecting physical and chemical soil properties

    Directory of Open Access Journals (Sweden)

    Paolo Bazzoffi

    Full Text Available The increasing production of urban waste requires urgent responses because of various environmental problems that arise when urban refuse is stored in landfills or incinerated. Recycling of domestic waste and composting of its organic fraction has been indicated as a possible disposal solution. A three-year experiment was conducted to quantify the minimum rate of urban refuse compost (URC addition able to improve some physical and chemical soil properties at the lowest cost and environmental impact. URC was added to a silty clay soil and to a sandy loam soil 0%, 3%, 6%, 9% rate (w/w. Samplings were made 12, 24 and 36 months after URC application. To study the only effect of compost on soil due to its interaction with the soil matrix, each soil-compost mixture was divided into three boxes and kept outdoors weed free. After 12 months, 3% URC resulted the minimum quantity able to ameliorate several soil properties. In silty clay soil this rate significantly ameliorated microaggregate stability and hydraulic conductivity, but negative effects were observed on electrical conductivity. After 24 months, 3% rate significantly increased soil organic matter content. In the sandy loam soil, after 12 months, 3% rate of URC determined a positive effect on organic matter and cone resistance in dry soil condition. Electrical conductivity increased at 3% URC addition. The minimum URC quantity affecting hydraulic conductivity and plastic limit was 6%, and 9% for the liquid limit. Under these experimental conditions, the lowest rate (3% of URC incorporation to soils appears to be the minimum quantity able to improve most of the soil properties influencing fertility. What the results show is that, to achieve sustainability of urban refuse compost application to agricultural soil, further research is needed to investigate soil property changes in the range between 0% and 3%.

  18. Minimum quantity of urban refuse compost affecting physical and chemical soil properties

    Directory of Open Access Journals (Sweden)

    Andrea Rocchini

    2011-02-01

    Full Text Available The increasing production of urban waste requires urgent responses because of various environmental problems that arise when urban refuse is stored in landfills or incinerated. Recycling of domestic waste and composting of its organic fraction has been indicated as a possible disposal solution. A three-year experiment was conducted to quantify the minimum rate of urban refuse compost (URC addition able to improve some physical and chemical soil properties at the lowest cost and environmental impact. URC was added to a silty clay soil and to a sandy loam soil 0%, 3%, 6%, 9% rate (w/w. Samplings were made 12, 24 and 36 months after URC application. To study the only effect of compost on soil due to its interaction with the soil matrix, each soil-compost mixture was divided into three boxes and kept outdoors weed free. After 12 months, 3% URC resulted the minimum quantity able to ameliorate several soil properties. In silty clay soil this rate significantly ameliorated microaggregate stability and hydraulic conductivity, but negative effects were observed on electrical conductivity. After 24 months, 3% rate significantly increased soil organic matter content. In the sandy loam soil, after 12 months, 3% rate of URC determined a positive effect on organic matter and cone resistance in dry soil condition. Electrical conductivity increased at 3% URC addition. The minimum URC quantity affecting hydraulic conductivity and plastic limit was 6%, and 9% for the liquid limit. Under these experimental conditions, the lowest rate (3% of URC incorporation to soils appears to be the minimum quantity able to improve most of the soil properties influencing fertility. What the results show is that, to achieve sustainability of urban refuse compost application to agricultural soil, further research is needed to investigate soil property changes in the range between 0% and 3%.

  19. Immunobiological properties of sesquiterpene lactones obtained by chemically transformed structural modifications of trilobolide.

    Science.gov (United States)

    Harmatha, Juraj; Vokáč, Karel; Buděšínský, Miloš; Zídek, Zdeněk; Kmoníčková, Eva

    2015-12-01

    Our previous research on immunostimulatory properties of trilobolide and its structurally related natural analogues isolated from Laser trilobum (L.) Borkh., encouraged us to investigate structurally related guaianolides belonging to a specific group of sesquiterpene lactones with characteristic glycol moiety attached to the lactone ring. Ever increasing attention has been paid to certain guaianolides such as thapsigargin and trilobolide for their promising anti-inflammatory, anticancer, anti-infectious and SERCA inhibitory activities. However, due to their alkylation capabilities, they might be cytotoxic. Search for compounds with preserved immunobiological properties and decreased cytotoxicity led us to transform some of their structural features, particularly those related to their side chain functionality. For this reason, we prepared a series of over 20 various deacylated, acyl modified, or relactonized derivatives of trilobolide. The immunobiological effects were screened in vitro using the rat peritoneal cells primed with lipopolysaccharide. Secretion of interferon-γ (IFN-γ), interleukins (IL) IL-1β, IL-6 and tumour necrosis factor-α (TNF-α) were determined by ELISA, and nitric oxide (NO) production by Griess reagent. Relation between the molecular structure and immunobiological activity was investigated. Acetylation at 7-OH and 11-OH positions of the lactone ring, or acyl modification of the guaianolide functionalities (including relactonization) of trilobolide, led to inability to stimulate secretion of cytokines and production of NO. Interestingly, minor structural changes achieved by catalytic hydrogenation or hydrogenolysis retained the original immunoactivity of trilobolide. It can be concluded that several new chemically transformed sesquiterpene lactones resembling the immunobiological properties of trilobolide or thapsigargin were prepared and identified. The implication of the lactone vicinal diol (glycol) moiety, combined with other structure

  20. A computational methodology for formulating gasoline surrogate fuels with accurate physical and chemical kinetic properties

    KAUST Repository

    Ahmed, Ahfaz

    2015-03-01

    Gasoline is the most widely used fuel for light duty automobile transportation, but its molecular complexity makes it intractable to experimentally and computationally study the fundamental combustion properties. Therefore, surrogate fuels with a simpler molecular composition that represent real fuel behavior in one or more aspects are needed to enable repeatable experimental and computational combustion investigations. This study presents a novel computational methodology for formulating surrogates for FACE (fuels for advanced combustion engines) gasolines A and C by combining regression modeling with physical and chemical kinetics simulations. The computational methodology integrates simulation tools executed across different software platforms. Initially, the palette of surrogate species and carbon types for the target fuels were determined from a detailed hydrocarbon analysis (DHA). A regression algorithm implemented in MATLAB was linked to REFPROP for simulation of distillation curves and calculation of physical properties of surrogate compositions. The MATLAB code generates a surrogate composition at each iteration, which is then used to automatically generate CHEMKIN input files that are submitted to homogeneous batch reactor simulations for prediction of research octane number (RON). The regression algorithm determines the optimal surrogate composition to match the fuel properties of FACE A and C gasoline, specifically hydrogen/carbon (H/C) ratio, density, distillation characteristics, carbon types, and RON. The optimal surrogate fuel compositions obtained using the present computational approach was compared to the real fuel properties, as well as with surrogate compositions available in the literature. Experiments were conducted within a Cooperative Fuels Research (CFR) engine operating under controlled autoignition (CAI) mode to compare the formulated surrogates against the real fuels. Carbon monoxide measurements indicated that the proposed surrogates

  1. Effect of chemical composition and alumina content on structure and properties of ceramic insulators

    Indian Academy of Sciences (India)

    Arman Sedghi; Nastaran Riahi-Noori; Naser Hamidnezhad; Mohammad Reza Salmani

    2014-04-01

    In the present work, six electrical porcelain compositions with different amount of alumina and silica have been prepared and fired in an industrial furnace at 1300°C. Density, porosity, bending strength and electrical strength were measured in the samples. In order to find a relationship between properties and sample microstructures, samples were analyzed by scanning electron microscope (SEM) and x-ray diffraction (XRD) techniques. The results showed that, with chemical composition of 53.5 wt.% SiO2 and 37.5 wt.% alumina, highest electrical strength of 21.97 kV/mm was achieved in fabricated electrical porcelains. Increasing amount of alumina up to 30 wt.% decreases quartz and cristobalite phases, but increases corundum phase 3 to 5 times. SEM observation revealed that dense particles and uniform distribution of long and thin needle shaped mullite are predominant in sample microstructures with highest electrical strength.

  2. Tribological properties of diamond films grown by plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Uniform and continuous diamond films have been deposited on Si, Mo, and many other substrates by plasma-enhanced chemical vapor deposition. We have developed processes to enhance the adhesion of diamond films to metal substrates for tribological applications. The tribological properties of the diamond films are found to be significantly different depending on their morphology, grain size, and roughness. However, under all cases tested using a ring-on-block tribotester, it is found that for diamond films with a small grain size of 1--3 μm, the coefficient of friction of the diamond films sliding against a steel ring under lubrication of a jet of mineral oil is about 0.04

  3. Physico-chemical and nutritional properties of cereal-pulse blends for bread making.

    Science.gov (United States)

    Dhingra, Shfali; Jood, Sudesh

    2002-01-01

    Supplementation of soy (full fat and defatted) and barley flours to wheat flour at 51 10, 15 and 20% levels were carried out to see their effect on physico-chemical and nutritional properties of blends for bread making. The gluten content and sedimentation value of flour blends decreased and water absorption capacity increased with increase in the level of soybean and barley flour separately and in combinations to bread flour. All the blends at 20% levels were found nutritionally superior but breads prepared from them found organoleptically unacceptable. However, addition of 15% barley flour, 10% full fat soy flour, 10% defatted soy flour, 15% full fat soy flour + barley flour and 15% defatted soy flour + barley flour to wheat flour not only increased the total protein, glutelin (protein fraction), total lysine, dietary fibre and beta-glucan contents of cereal-pulse blends for bread making, but could also produce a product of acceptable quality. PMID:12418802

  4. Physico-chemical properties of ready to eat, shelf-stable pasta during storage.

    Science.gov (United States)

    Carini, E; Curti, E; Cassotta, F; Najm, N E O; Vittadini, E

    2014-02-01

    The changes in physico-chemical properties of RTE shelf stable pasta were studied during storage with a multianalytical and multidimensional approach (with special focus on water status) to understand the ageing process in this product. Pasta hardness and amylopectin recrystallisation increased, macroscopic water status indicators and proton molecular translational mobility remained constant, and significant changes were measured in the proton rotational molecular mobility indicators ((1)H FID, (1)H T2) during storage. Since the main changes observed in RTE pasta during storage were similar to those observed in other cereal-based products, it would be interesting to verify the effect of the anti-staling methods commonly used in the cereal processing industry in improving RTE pasta shelf-stability.

  5. EFFECT OF PRESSURE INDUCED GRAFT COPOLYMERIZATION ON THE PHYSICO-CHEMICAL PROPERTIES OF BIO-FIBERS

    Directory of Open Access Journals (Sweden)

    Amar Singh Singha

    2010-04-01

    Full Text Available The present study deals with the surface modification of Agave americana L. fiber through graft copolymerization of methyl methacrylate under pressure in the presence of ceric ammonium nitrate as redox initiator. The various reaction parameters such as reaction time, pressure, concentration of nitric acid, initiator, and monomer, etc. were optimized to have the maximum graft yield of 13.6%. The grafted fibers were then subjected to the evaluation of different physico-chemical properties such as swelling behavior, solubility, moisture absorption under different humidity levels, resistance to acids and bases, etc. It was observed that swelling behavior, solubility behavior, and moisture absorbance decreased with increase in grafting, whereas resistance to acids and bases increased with grafting. The fibers grafted under the optimized conditions were then characterized by Fourier transform infra-red spectroscopy, scanning electron microscopy, thermogravimetric analysis, and x-ray diffraction techniques.

  6. Comparison of some physico-chemical properties of irradiated cereal starches, separated or contained in flour

    International Nuclear Information System (INIS)

    In this study some physico-chemical properties of separated wheat starch from flour type 500 and 850, rye starch from flour type 720 and triticale starch from flour type 680 were compared. All starches were irradiated with medium doses of gamma rays: 2,3 and 5 kGy directly (after their separation from flour) and in flour. The water binding capacity of starches, their solubility in water and reduction capacity were found to depend on the dose applied and the method of irradiation, individually for each starch. Additional direct irradiation of all starches caused a smaller decrease in the viscosity of starch pastes and a stronger inhibition of the retrogradation process, in comparison to the starches separated from the irradiated flours. (author)

  7. Tuning the Electrical Properties of Graphene via Nitrogen Plasma-Assisted Chemical Modification.

    Science.gov (United States)

    Jung, Min Wook; Song, Wooseok; Jung, Dae Sung; Lee, Sun Sook; Park, Chong-Yun; An, Ki-Seok

    2016-03-01

    The control in electrical properties of graphene is essentially required in order to realize graphenebased nanoelectronics. In this study, N-doped graphene was successfully obtained via nitrogen plasma treatment. Graphene was synthesized on copper foil using thermal chemical vapor deposition. After N2 plasma treatment, the G-band of the graphene was blueshifted and the intensity ratio of 2D- to G-bands decreased with increasing the plasma power. Pyrrolic-N bonding configuration induced by N2 plasma treatment was studied by X-ray photoelectron spectroscopy. Remarkably, electrical characterization including Hall measurement and I-V characteristics of the N-doped graphene exhibit semiconducting behavior as well as the n-type doping effect. PMID:27455703

  8. Effect of the heat treatment on physical and chemical properties of Pinus caribaea wood

    Directory of Open Access Journals (Sweden)

    Dallyene da Silva Poubel

    2013-09-01

    Full Text Available This study evaluated the effect of the heat treatment on physical properties (density, equilibrium moisture content, mass loss, volumetric and linear swelling and shrinkage and chemical composition of normal (opposite side and compression wood of Pinus caribaea Morelet. Samples of 25 x 25 x 50 mm were heat-treated under two different temperatures: 200 and 220 ºC. The results indicated a reduction in equilibrium moisture content and swelling and shrinkage following heat treatment, independent of wood type. The compression wood showed higher longitudinal swelling than normal one, however, after heat treatment, the improvements were similar between both wood types. Samples heat-treated at 200 and 220 ºC had mass losses of 9.94 and 21.03 %, respectively. The heat treatment promoted a relative increase in lignin content and a decrease in holocellulose and α-cellulose contents, indicating the occurrence of thermal degradation of these components.

  9. Chemical Variation in Volatiles of Craniotome furcata: Correlation with Soil Properties

    Directory of Open Access Journals (Sweden)

    Shalini Singh

    2013-08-01

    Full Text Available The essential oils from the aerial parts of ten wild growing Craniotome furcata (Link. O. Kuntze of the family Lamiaceae collected from different locations in Uttarakhand, India, was analyzed by capillary GC and GC/MS. The oils were rich in sesquiterpenoids. The cluster analysis showed the presence of four groups. Group-I was significantly rich in δ-elemene and germacrene D while group-II had germacrene D in abundant quantity. α-Bisabolol oxide A, α-cadinol and germacrene D-4-ol were major constituents of group-III. Group-IV showed the presence of α-muurolol and germacrene D as major constituents. Germacrene D was found to be present in all the samples of C. furcata collected from different locations and was positively correlated with the altitude of the collection regions. Chemical variation in the volatiles was statistically correlated with altitude and soil properties.

  10. Preparation and properties of nano-composite ceramic coating by thermo chemical reaction method

    Institute of Scientific and Technical Information of China (English)

    MA Zhuang; SUN Fang-hong; LI Zhi-chao

    2007-01-01

    Nano-composite ceramic coating was fabricated on Q235 steel through thermo chemical reaction method. Structure of the coating was analyzed and the properties were tested. The results show that a few of new ceramic phases, such as MgAl2O4, ZnAl2O4,Al2SiO5, Ni3Fe and Fe3Al, are formed on the coating during the process of solidifying at 600 ℃. The ceramic coating is dense and the high bonding strength is obtained. The average bonding strength between the coating and matrix could be 14.22 MPa. The acid resistance of the coating increase by 8.8 times, the alkali resistance by 4.1 times, the salt resistance by 10.3 times, and the wear resistance by 2.39 times.

  11. Tuning the Electrical Properties of Graphene via Nitrogen Plasma-Assisted Chemical Modification.

    Science.gov (United States)

    Jung, Min Wook; Song, Wooseok; Jung, Dae Sung; Lee, Sun Sook; Park, Chong-Yun; An, Ki-Seok

    2016-03-01

    The control in electrical properties of graphene is essentially required in order to realize graphenebased nanoelectronics. In this study, N-doped graphene was successfully obtained via nitrogen plasma treatment. Graphene was synthesized on copper foil using thermal chemical vapor deposition. After N2 plasma treatment, the G-band of the graphene was blueshifted and the intensity ratio of 2D- to G-bands decreased with increasing the plasma power. Pyrrolic-N bonding configuration induced by N2 plasma treatment was studied by X-ray photoelectron spectroscopy. Remarkably, electrical characterization including Hall measurement and I-V characteristics of the N-doped graphene exhibit semiconducting behavior as well as the n-type doping effect.

  12. Changes in mechanical and chemical wood properties by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Schnabel, Thomas, E-mail: thomas.schnabel@fh-salzburg.ac.at [Salzburg University of Applied Sciences, Department of Forest Products Technology and Wood Constructions, Marktstraße 136a, 5431 Kuchl (Austria); Huber, Hermann [Salzburg University of Applied Sciences, Department of Forest Products Technology and Wood Constructions, Marktstraße 136a, 5431 Kuchl (Austria); Grünewald, Tilman A. [BOKU University of Natural Resources and Life Sciences, Institute of Physics and Materials Science, Peter Jordan Straße 82, 1190 Vienna (Austria); Petutschnigg, Alexander [Salzburg University of Applied Sciences, Department of Forest Products Technology and Wood Constructions, Marktstraße 136a, 5431 Kuchl (Austria); BOKU University of Natural Resources and Life Sciences, Konrad Lorenzstraße 24, 3430 Tulln (Austria)

    2015-03-30

    Highlights: • Changes in wood due to electron beam irradiations (EBI) were evaluated. • Wood components undergo different altering mechanisms due to the irradiation. • Chemical reactions in wood lead to better surface hardness of low irradiated wood. - Abstract: This study deals with the influence of various electron beam irradiation (EBI) dosages on the Brinell hardness of Norway spruce. The results of the hardness measurements and the FT-IR spectroscopic analysis show different effects of the EBI at dosages of 25, 50, 100 and 200 kGy. It was assumed that the lignin and carbohydrates undergo different altering mechanisms due to the EBI treatment. New cleavage products and condensation reactions of lignin and carbohydrates lead to better surface hardness of low irradiated wood samples. These results provide a useful basis for further investigations on the changes in wood chemistry and material properties due to electron beam irradiations.

  13. Effects of Biochar on Chemical Properties of Three Types of Soil and Nutrient Uptake of Maize under Drought Stress

    Directory of Open Access Journals (Sweden)

    ThiHuong Nguyen

    2015-09-01

    Full Text Available This study was conducted to determine the effects of biochar on the chemical properties of three types of soils and the nutrient uptake and yield of the maize plant grown on the soils. The experimental results are as follows: (i In Loess soil, when the biochar application rate was 15 t/ha, the soil chemical properties was barely improved, but the nutrient uptake of maize was obviously improved. The amount of biochar application was at 30 t/ha, the result was just on the contrary and 60 t/ha application of biochar performed a poor effect on the soil chemical properties as well as on the nutrient uptake of maize. (ii In sandy soil, when the application of biochar reached to 15 t/ha, there were not remarkable effects on soil chemical properties and moderate promoting effect on nutrient uptake of maize. Additionally, the biochar application at a rate of 30 t/ha led to a small effect on the both, but 60 t/ha amount made a significant improvement in both. (iii In loessal soil, applying 15 t/ha biochar to soil had a moderate effect on chemical properties’ improvement, but the promotional effect on nutrient uptake of maize is poor. When the amount of biochar application was at 30 t/ha, soil chemical properties were significantly improved but the effect on nutrient uptake of maize was moderate. However, 60 t/ha biochar application obviously improved nutrient uptake of maize, but the effect of chemical properties improvement was poor.

  14. Physico-chemical properties and biological effects of diesel and biomass particles

    KAUST Repository

    Longhin, Eleonora

    2016-05-15

    © 2016 Elsevier Ltd. Diesel combustion and solid biomass burning are the major sources of ultrafine particles (UFP) in urbanized areas. Cardiovascular and pulmonary diseases, including lung cancer, are possible outcomes of combustion particles exposure, but differences in particles properties seem to influence their biological effects.Here the physico-chemical properties and biological effects of diesel and biomass particles, produced under controlled laboratory conditions, have been characterized. Diesel UFP were sampled from a Euro 4 light duty vehicle without DPF fuelled by commercial diesel and run over a chassis dyno. Biomass UFP were collected from a modern automatic 25 kW boiler propelled by prime quality spruce pellet. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of both diesel and biomass samples showed aggregates of soot particles, but in biomass samples ash particles were also present. Chemical characterization showed that metals and PAHs total content was higher in diesel samples compared to biomass ones.Human bronchial epithelial (HBEC3) cells were exposed to particles for up to 2 weeks. Changes in the expression of genes involved in xenobiotic metabolism were observed after exposure to both UFP already after 24 h. However, only diesel particles modulated the expression of genes involved in inflammation, oxidative stress and epithelial-to-mesenchymal transition (EMT), increased the release of inflammatory mediators and caused phenotypical alterations, mostly after two weeks of exposure.These results show that diesel UFP affected cellular processes involved in lung and cardiovascular diseases and cancer. Biomass particles exerted low biological activity compared to diesel UFP. This evidence emphasizes that the study of different emission sources contribution to ambient PM toxicity may have a fundamental role in the development of more effective strategies for air quality improvement.

  15. Effect of Drying Temperature on the Chemical Properties and Diffusivity of belimbi (averrhoa belimbi)

    Science.gov (United States)

    Shahari, N.; Jamil, N.; Rasmani, K. A.; Nursabrina

    2015-09-01

    In recent years, many dried fruit products have been developed in response to a strong demand by the customer. This type of fruit has a different composition and hence different moisture diffusivity (D). During drying, Fick's Law of diffusion, which describes the movement of liquid water was used to calculate this diffusivity. However diffusivity has strong effects on the material drying characteristics and these must be determined. In this paper, Fick's Law of diffusion with different kinds of boundary conditions was solve using separation of variable (SOV). In order to get the value of D, results obtained using SOV will be compared with the results from the drying of belimbi at temperature of 40°C, 50°C and 60°C. Although the results show that variation in the values of diffusivity for different temperatures is relatively small, but the variation in the total time required for drying is significantly bigger: between 3-7 hours. Its shown that diffusivity is an important measurement and should be considered in the modeling of the drying process. The chemical properties of belimbi slices in terms of vitamin C, total ash and antioxidant activity with different air temperatures and pretreatment were also investigated. Higher drying temperatures gives less drying time, a lower vitamin C and antioxidant activity but a greater total of ash, whilst pre-treatment can increased vitamin C and antioxidant activity. The results show that pre-treatment and the drying temperature are important variables to improve mass and heat transfer, as well as the belimbi chemical properties.

  16. Physico-chemical properties and biological effects of diesel and biomass particles.

    Science.gov (United States)

    Longhin, Eleonora; Gualtieri, Maurizio; Capasso, Laura; Bengalli, Rossella; Mollerup, Steen; Holme, Jørn A; Øvrevik, Johan; Casadei, Simone; Di Benedetto, Cristiano; Parenti, Paolo; Camatini, Marina

    2016-08-01

    Diesel combustion and solid biomass burning are the major sources of ultrafine particles (UFP) in urbanized areas. Cardiovascular and pulmonary diseases, including lung cancer, are possible outcomes of combustion particles exposure, but differences in particles properties seem to influence their biological effects. Here the physico-chemical properties and biological effects of diesel and biomass particles, produced under controlled laboratory conditions, have been characterized. Diesel UFP were sampled from a Euro 4 light duty vehicle without DPF fuelled by commercial diesel and run over a chassis dyno. Biomass UFP were collected from a modern automatic 25 kW boiler propelled by prime quality spruce pellet. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of both diesel and biomass samples showed aggregates of soot particles, but in biomass samples ash particles were also present. Chemical characterization showed that metals and PAHs total content was higher in diesel samples compared to biomass ones. Human bronchial epithelial (HBEC3) cells were exposed to particles for up to 2 weeks. Changes in the expression of genes involved in xenobiotic metabolism were observed after exposure to both UFP already after 24 h. However, only diesel particles modulated the expression of genes involved in inflammation, oxidative stress and epithelial-to-mesenchymal transition (EMT), increased the release of inflammatory mediators and caused phenotypical alterations, mostly after two weeks of exposure. These results show that diesel UFP affected cellular processes involved in lung and cardiovascular diseases and cancer. Biomass particles exerted low biological activity compared to diesel UFP. This evidence emphasizes that the study of different emission sources contribution to ambient PM toxicity may have a fundamental role in the development of more effective strategies for air quality improvement. PMID:27194366

  17. Chemical nature of boron and nitrogen dopant atoms in graphene strongly influences its electronic properties.

    Science.gov (United States)

    Lazar, Petr; Zbořil, Radek; Pumera, Martin; Otyepka, Michal

    2014-07-21

    Boron and nitrogen doped graphenes are highly promising materials for electrochemical applications, such as energy storage, generation and sensing. The doped graphenes can be prepared by a broad variety of chemical approaches. The substitution of a carbon atom should induce n-type behavior in the case of nitrogen and p-type behavior in the case of boron-doped graphene; however, the real situation is more complex. The electrochemical experiments show that boron-doped graphene prepared by hydroboration reaction exhibits similar properties as the nitrogen doped graphene; according to theory, the electrochemical behavior of B and N doped graphenes should be opposite. Here we analyze the electronic structure of N/B-doped graphene (at ∼5% coverage) by theoretical calculations. We consider graphene doped by both substitution and addition reactions. The density of states (DOS) plots show that graphene doped by substitution of the carbon atom by N/B behaves as expected, i.e., as an n/p-doped material. N-doped graphene also has a lower value of the workfunction (3.10 eV) with respect to that of the pristine graphene (4.31 eV), whereas the workfunction of B-doped graphene is increased to the value of 5.57 eV. On the other hand, the workfunctions of graphene doped by addition of -NH2 (4.77 eV) and -BH2 (4.54 eV) groups are both slightly increased and therefore the chemical nature of the dopant is less distinguishable. This shows that mode of doping depends significantly on the synthesis method used, as it leads to different types of behaviour, and, in turn, different electronic and electrochemical properties of doped graphene, as observed in electrocatalytic experiments. This study has a tremendous impact on the design of doped graphene systems from the point of view of synthetic chemistry.

  18. Optical property tuning of bismuth chalcogenides using chemical intercalation (Presentation Recording)

    Science.gov (United States)

    Yao, Jie

    2015-10-01

    Two-dimensional (2D) materials with natural layer structures have been proven to provide extraordinary physical and chemical properties. Bismuth chalcogenides are examples of such two-dimensional materials. They are strongly bonded within layers and weak van der Waals interaction ties those layers together. Such naturally layered structure allows chemical intercalation of foreign atoms into the van der Waals gaps. Here, we show that by adding large number of copper atoms into van der Waals gaps of bismuth chalcogenides, we observed counter-intuitive enhancement of optical transparency together with improved electrical conductivity, which is on the contrary to most bulk materials in which doping reduces the light transmission. This surprising behavior is caused by substantial tuning of material optical property and nanophotonic anti-reflection effect unique to ultra-thin nanoplates. With the intercalation of copper atoms, large number of electrons have been added into the semiconducting material system and effectively lift the Fermi level of the resulting material to its conduction band, as proved by our densityfunctional- theory computations. Occupied lower states in the conduction band do not allow the optical excitation of electrons in the valence band to the bottom of the conduction band, leading to an effective widening of optical band gap. Optical transmission is further enhanced by constructive interference of reflected beams as bismuth chalcogenides have large permittivity than the environment. The synergy of these two effects in two-dimensional nanostructures can be exploited for various optoelectronic applications including transparent electrode. The reversible intercalation process allows potential dynamic tuning capability.

  19. Fauna-associated Changes in Chemical and Biochemical Properties of Soil

    Institute of Scientific and Technical Information of China (English)

    G. TRIPATHI; B. M. SHARMA

    2006-01-01

    Objective To study the impacts of abundance of woodlice, termites, and mites on some functional aspects of soil in order to elucidate the specific role of soil fauna in improving soil fertility in desert. Methods Fauna-rich sites were selected as experimental sites and adjacent areas were taken as control. Soil samples were collected from both sites. Soil respiration was measured at both sites. The soil samples were sent to laboratory, their chemical and biochemical properties were analyzed.Results Woodlice showed 25% decrease in organic carbon and organic matter as compared to control site. Whereas termites and mites showed 58% and 16% decrease in organic carbon and organic matter. In contrast, available nitrogen (nitrate and ammonical both) and phosphorus exhibited 2-fold and 1.2-fold increase, respectively. Soil respiration and dehydrogenase activity at the sites rich in woodlice, termites and mites produced 2.5-, 3.5- and 2-fold increases, respectively as compared to their control values. Fauna-associated increase in these biological parameters clearly reflected fauna-induced microbial activity in soil. Maximum decrease in organic carbon and increase in nitrate-nitrogen and ammonical-nitrogen, available phosphorus, soil respiration and dehydrogenase activity were produced by termites and minimum by mites reflecting termite as an efficient soil improver in desert environment. Conclusion The soil fauna-associated changes in chemical (organic carbon, nitrate-nitrogen, ammonical-nitrogen, phosphorus) and biochemical (soil respiration, dehydrogenase activity) properties of soil improve soil health and help in conservation of desert pedoecosystem.

  20. Chemical and Antioxidant Properties of Wild Edible Mushrooms from Native Nothofagus spp. Forest, Argentina.

    Science.gov (United States)

    Toledo, Carolina V; Barroetaveña, Carolina; Fernandes, Ângela; Barros, Lillian; Ferreira, Isabel C F R

    2016-01-01

    This study addresses issues regarding chemical and bioactive properties of nine wild edible mushrooms from native Nothofagus forest from Patagonia, Argentina. Macronutrients, sugars, fatty acids, tocopherols, organic acids, phenolic compounds and antioxidant properties were determined. Protein was found in high levels and varied between 3.35 g/100 g dw in Cyttaria hariotii and 22.29 g/100 g dw in Lepista nuda. All of them presented mannitol and trehalose as main sugars. Mannitol was significantly higher in Ramaria patagonica, although absent in Fistulina endoxantha, whereas trehalose predominated in Aleurodiscus vitellinus, Hydropus dusenii, Cortinarius magellanicus, C. hariotii, Grifola gargal and L. nuda, ranging from 1.15 to 10.26 g/100 g dw; it was absent in R. patagonica. The major fatty acid found was linoleic acid, followed by oleic acid and palmitic acid. All species presented oxalic and fumaric acids, while some also had malic, quinic and citric acids. Tocopherols composition was variable. Cortinarius magellanicus presented significantly higher contents of both α-tocopherol and β-tocopherol. R. patagonica presented the best results in all the antioxidant activity assays (EC50 values ≤ 1 mg/mL) and the highest content of phenolic compounds presenting gallic, p-hydroxybenzoic, p-coumaric and cinnamic acids. This study constitutes the first report on chemical composition and nutritional value of most of these edible mushroom species. Furthermore, it provides important information necessary to characterize and define the use of these species as gastronomic delicacies, functional foods and sources of bioactive compounds. PMID:27617993

  1. Effect of pozzolans with different physical and chemical characteristics on concrete properties

    Directory of Open Access Journals (Sweden)

    Paiva, H.

    2016-06-01

    Full Text Available The durability of concrete structures is an important issue nowadays. Specifically in the case of reinforced concrete bridges or other infrastructures one of the main form of environmental attack is the penetration of chloride ions, which leads to corrosion of concrete steel reinforcement. This study aims to evaluate the effect of the introduction of metakaolin and diatomite, two chemically and physically different pozzolans, on the resistance of concrete to the penetration of chlorides but also the effect on other properties of concrete, namely, its compressive strength and its porosity distribution. The results of this study show that the pozzolans physical and chemical characteristics have a strong influence on the pozzolans behavior and, consequently, on the concrete properties.La durabilidad de las estructuras de hormigón es un tema importante hoy en día. En concreto, en el caso de los puentes de hormigón armado u otras infraestructuras, el principal factor de agresión medioambiental es la penetración de iones cloruro, lo que conduce a la corrosion del acero de refuerzo del hormigón. Este estudio tiene como objetivo evaluar el efecto de la introducción de metacaolín y diatomita, dos puzolanas química y físicamente diferentes, sobre la resistencia del hormigón a la penetración de cloruros, y también sobre otras de sus propiedades como la distribución de su porosidad o su resistencia a compresión. Los resultados de este estudio muestran que las características fisicoquímicas de las puzolanas tienen una fuerte influencia en su comportamiento y en consecuencia, en las propiedades del hormigón.

  2. Caustic-Side Solvent Extraction Chemical and Physical Properties Progress in FY 2000 and FY 2001.

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, BA

    2002-04-17

    The purpose of this work was to provide chemical- and physical-property data addressing the technical risks of the Caustic-Side Solvent Extraction (CSSX) process as applied specifically to the removal of cesium from alkaline high-level salt waste stored at the US Department of Energy Savannah River Site. As part of the overall Salt Processing Project, this effort supported decision-making in regards to selecting a preferred technology among three alternatives: (1) CSSX, (2) nonelutable ion-exchange with an inorganic silicotitanate material and (3) precipitation with tetraphenylborate. High risks, innate to CSSX, that needed specific attention included: (1) chemical stability of the solvent matrix, (2) radiolytic stability of the solvent matrix, (3) proof-of-concept performance of the proposed process flowsheet with simulated waste, and (4) performance of the CSSX flowsheet with actual SRS high-level waste. This body of work directly addressed the chemical-stability risk and additionally provided supporting information that served to plan, carry out, and evaluate experiments conducted by other CSSX investigators addressing the other high risks. Information on cesium distribution in extraction, scrubbing, and stripping served as input for flowsheet design, provided a baseline for evaluating solvent performance under numerous stresses, and contributed to a broad understanding of the effects of expected process variables. In parallel, other measurements were directed toward learning how other system components distribute in the flowsheet. Such components include the solvent components themselves, constituents of the waste, and solvent-degradation products. Upon understanding which components influence flowsheet performance, it was then possible to address in a rational fashion how to clean up the solvent and maintain its stable function.

  3. Mapping dry matter production of Tifton 85 and its correlation with the soil chemical properties

    Directory of Open Access Journals (Sweden)

    Osmar Henrique de Castro Pias

    2015-07-01

    Full Text Available The creation of cattle in the semi extensive system has currently been the most used by the farmers on Brazil, however, problems such as degradation of pastures are committing this production system, reducing the production of forager and consequently the profitability of producers. In this sense, the aim of this study was to perform the mapping of the dry mass production, nitrogen accumulation, phosphorus and potassium in the Tifton 85, and evaluate their correlations with the chemical attributes in different layers of the soil profile. The study was carried out in an area of 4.3 ha constituted of Tifton 85 in the city of Vista Gaucha - RS, Brazil, during the months from October to December in the year of 2012. The experimental area was georeferenced and divided into a sample mesh of 50 x 50 m, resulting in 16 sampling points. It was conducted two cuts on Tifton 85 to evaluate the dry mass production. Soil sampling was done in the layers from 0.00 - 0.10 m, 0.10 - 0.20 and 0.20 - 0.40 m. The data were submitted to descriptive statistical analysis and linear correlation matrix of Pearson, being the results specialized in thematic maps. The production of dry mass, nitrogen accumulation, phosphorus and potassium by Tifton 85 showed coefficients of variation ranked of high to very high, and in generally, demonstrated low correlation with the soil chemical properties, independently of the layer profile evaluated.

  4. Physical properties and chemical durability of selected zirconia containing silicate glasses

    Directory of Open Access Journals (Sweden)

    ELEONÓRA GAŠPÁREKOVÁ

    2011-12-01

    Full Text Available Density, thermal expansion, glass transition temperature, refractive index, molar refractivity and chemical durability of five- and six-component glasses with as weighted composition xNa2O·(15-xK2O·yCaO∙(10-yZnO∙zZrO2∙(75-zSiO2 (x = 0, 7.5, 15; y = 0, 5, 10; z = 5, 7 were measured. The obtained experimental data were merged together with the previous results obtained for analogous glasses with lower zirconia content. The full set of glasses enabled the quantitative statistical estimation of possible mixed-oxide effects. The results of the multilinear regression analysis pointed out the ideal behavior of molar volume and molar refractivity. The strongest influence of mutual oxide interactions was found for chemical durability and glass transition temperature. The regression analysis of compositional dependence of metastable melt thermal expansion coefficient practically failed. The need of property-composition study based on the thermodynamic model was pointed out. Qualitatively the obtained results confirmed those previously obtained for the analogous glasses with zirconia content reaching up to 3 mol. %.

  5. DFT modeling of the electronic and magnetic structures and chemical bonding properties of intermetallic hydrides

    International Nuclear Information System (INIS)

    This thesis presents an ab initio study of several classes of intermetallics and their hydrides. These compounds are interesting from both a fundamental and an applied points of view. To achieve this aim two complementary methods, constructed within the DFT, were chosen: (i) pseudo potential based VASP for geometry optimization, structural investigations and electron localization mapping (ELF), and (ii) all-electrons ASW method for a detailed description of the electronic structure, chemical bonding properties following different schemes as well as quantities depending on core electrons such as the hyperfine field. A special interest is given with respect to the interplay between magneto-volume and chemical interactions (metal-H) effects within the following hydrided systems: binary Laves (e.g. ScFe2) and Haucke (e.g. LaNi5) phases on one hand, and ternary cerium based (e.g. CeRhSn) and uranium based (e.g. U2Ni2Sn) alloys on the other hand. (author)

  6. Anatomical and Chemical Characteristics of a Rolling Leaf Mutant of Rice and Its Ecophysiological Properties

    Institute of Scientific and Technical Information of China (English)

    BAI Lei; DUAN Zhuang-qin; WANG Jun-min; AN Li-zhe; ZHAO Zhi-guang; CHEN Kun-ming

    2008-01-01

    The anatomical and chemical characteristics of a rolling leaf mutant (r/m) of rice (Oryza sativa L.) and its ecophysiological properties in photosynthesis and apoplastic transport were investigated. Compared with the wild type (WT),the areas of whole vascular bundles and xylem as well as the ratios of xylem area/whole vascular bundles area and xylem area/phloem area were higher in r/m, whereas the area and the width of foliar bulliform cell were lower. The Fourier transform infrared (FTIR) microspectroscopy spectra of foliar cell walls differed greatly between r/m and WT. The r/m exhibited lower protein and polysaccharide contents of foliar cell walls. An obvious reduction of pectin content was also found in r/m by biochemical measurements. Moreover, the rate of photosynthesis was depressed while the conductance of stoma and the intercellular CO2 concentration were enhanced in rim. The PTS fluorescence, which represents the ability of apoplastic transport, was 11% higher in r/m than in WT. These results suggest that the changes in anatomical and chemical characteristics of foliar vascular bundles, such as the reduction of proteins, pectins, and other polysaccharides of foliar cell walls, participate in the leaf rolling mutation, and consequently lead to the reduced photosynthetic dynamics and apoplastic transport ability in the mutant.

  7. Effects of Organic Fertilizer on Fruit Quality and Acidified Soil Chemical Properties in Yantai Orchard

    Institute of Scientific and Technical Information of China (English)

    Yao SUN; Yiming WANG; Peiping ZHANG

    2016-01-01

    Objective] This study aimed to investigate the improving effect of organic fertilizer on acidified soil as wel as their ef-fects on fruit quality and quantity in Yantai orchard. [Method] Plot experiment was conducted to investigate the effects of organic fertilizer on fruit yield and quality of Red Fuji and chemical properties of acidified soil. [Result] The apple yield in acidified soil applied with organic fertilizer al increased. Under the application of biological organic fertilizer, the apple yield was higher, and it was 8.92% higher than that in the control group. Under the mixed application of chemical fertilizer and biological organic fertiliz-er, the growth and development of apple trees were improved, and the total soluble solid (TSS) content, vitamin C (Vc) content and TSS-acid ratio in mature apples al increased. The application of organic fertilizer significantly reduced soil acidity. Compared with those in the control group, the soil pH value, organic matter content and alkali-hydrolyzable nitrogen content under the ap-plication of biological organic fertilizer were increased by 8.33%, 15.10% and 30.80%, respectively. [Conclusion] The application of biological organic fertilizer could improve the yield of apple in acidified soil.

  8. The physico-chemical properties and biostimulative activities of humic substances regenerated from lignite.

    Science.gov (United States)

    David, Jan; Smejkalová, Daniela; Hudecová, Sárka; Zmeškal, Oldřich; von Wandruszka, Ray; Gregor, Tomáš; Kučerík, Jiří

    2014-01-01

    The positive effect of humic acids on the growth of plant roots is well known, however, the mechanisms and role of their physical structure in these processes have not been fully explained yet. In this work, South-Moravian lignite was oxidized by means of nitric acid and hydrogen peroxide to produce a set of regenerated humic acids. The elemental composition, solid state stability and solution characteristics were determined and correlated in vitro with their biological activity. A modified hydroponic method was applied to determine the effects of their potassium salts on Zea mays seedlings roots with respect to the plant weight, root length, root division, and starch and protein content. The relations between the determined parameters were evaluated through Principal Component Analysis and Pearson's correlation coefficients. The results indicated that the most important factor determining the biological activity of South-Moravian lignite potassium humates is related to the nature of self-assemblies, while the chemical composition had no direct connection with the root growth of Zea mays seedlings. It was demonstrated a controlled processing that provided humic substances with different chemical and physicochemical properties and variable biological activity. PMID:24790812

  9. Stellar haloes of simulated Milky Way-like galaxies: Chemical and kinematic properties

    CERN Document Server

    Tissera, P B; Beers, T; Carollo, C

    2013-01-01

    We investigate the chemical and kinematic properties of the diffuse stellar haloes of six simulated Milky Way-like galaxies from the Aquarius Project. Binding energy criteria are adopted to defined two dynamically distinct stellar populations: the diffuse inner and outer haloes, which comprise different stellar sub-populations with particular chemical and kinematic characteristics. Our simulated inner- and outer-halo stellar populations have received contributions from debris stars (formed in sub-galactic systems while they were outside the virial radius of the main progenitor galaxies) and endo-debris stars (those formed in gas-rich sub-galactic systems inside the dark matter haloes). The inner haloes possess an additional contribution from disc-heated stars in the range $\\sim 3 - 30 %$, with a mean of $\\sim 20% $. Disc-heated stars can exhibit signatures of kinematical support, in particular among the youngest ones. Endo-debris plus disc-heated stars define the so-called \\insitu stellar populations. In both...

  10. Chemical characterization, antioxidant, anti-inflammatory and cytotoxic properties of bee venom collected in Northeast Portugal.

    Science.gov (United States)

    Sobral, Filipa; Sampaio, Andreia; Falcão, Soraia; Queiroz, Maria João R P; Calhelha, Ricardo C; Vilas-Boas, Miguel; Ferreira, Isabel C F R

    2016-08-01

    Bee venom (BV) or apitoxin is a complex mixture of substances with reported biological activity. In the present work, five bee venom samples obtained from Apis mellifera iberiensis from the Northeast Portugal (two different apiaries) were chemically characterized and evaluated for their antioxidant, anti-inflammatory and cytotoxic properties. The LC/DAD/ESI-MS(n) analysis of the samples showed that melittin was the most abundant compound, followed by phospholipase A2 and apamin. All the samples revealed antioxidant and anti-inflammatory activity but without a direct relation with any of the individual chemical components identified. The results highlight that there are specific concentrations (present in BV5) in which these compounds are more active. The BV samples showed similar cytotoxicity for all the tested tumour cell lines (MCF-7, NCI-H460, HeLa and HepG2), being MCF-7 and HeLa the most susceptible ones. Nevertheless, the studied samples seem to be suitable to treat breast, hepatocellular and cervical carcinoma because at the active concentrations, the samples were not toxic for non-tumour cells (PLP2). Regarding the non-small cell lung carcinoma, BV should be used under the toxic concentration for non-tumour cells. Overall, the present study corroborates the enormous bioactive potential of BV being the first report on samples from Portugal. PMID:27288930

  11. Biocomposites from waste derived biochars: Mechanical, thermal, chemical, and morphological properties.

    Science.gov (United States)

    Das, Oisik; Sarmah, Ajit K; Bhattacharyya, Debes

    2016-03-01

    To identify a route for organic wastes utilisation, biochar made from various feedstocks (landfill pine saw dust, sewage sludge, and poultry litter) and at diverse pyrolysis conditions, were collected. These biochars were used to fabricate wood and polypropylene biocomposites with a loading level of 24 mass%. The composites were tested for their mechanical, chemical, thermal, morphological, and fire properties. The poultry litter biochar biocomposite, with highest ash content, was found to have high values of tensile/flexural strength, tensile/flexural modulus, and impact strength, compared to other composites. In general, addition of all the biochars enhanced the tensile/flexural moduli of the composites. The crystal structure of polypropylene in the composite was intact after the incorporation of all the biochars. The final chemical and crystal structure of the composite were an additive function of the individual components. The biochar particles along with wood acted as nucleating agents for the recrystallization of polypropylene in composite. Each component in the composites was found to decompose individually under thermal regime. The electron microscopy revealed the infiltration of polypropylene into the biochar pores and a general good dispersion in most composites. The poultry litter composite was found to have lower heat release rate under combustion regime. PMID:26724232

  12. Changes in chemical composition and antioxidative properties of rye ginger cakes during their shelf-life.

    Science.gov (United States)

    Zieliński, Henryk; del Castillo, Maria Dolores; Przygodzka, Małgorzata; Ciesarova, Zuzana; Kukurova, Kristina; Zielińska, Danuta

    2012-12-15

    Changes in chemical composition and antioxidative properties of rye ginger cakes during their shelf-life were investigated in this study. In particular, the changes in antioxidants content, antioxidative and reducing capacity, and Maillard reaction development in rye ginger cakes after long-term storage were addressed. Ginger cakes produced according to the traditional and current recipe were stored for 5 years at room temperature in a dark place. The total phenolic compounds (TPC), inositol hexaphosphate (IP6), reduced (GSH) and oxidised glutathione (GSSG) contents, antioxidant and reducing capacity and Maillard reaction products (MRPs) were determined in ginger cakes after storage and then compared to those measured after baking. After long-term storage a decrease in TPC and IP6 contents in cakes was noted. In contrast, an increase in antioxidative and reducing capacity of stored cakes was observed. Long-term storage induced formation of furosine, advanced and final Maillard reaction products and caused changes in both reduced and oxidised forms of glutathione. After long-term storage the modest changes in furosine, FAST index and browning in ginger cake formulated with dark rye flour may suggest that this product is the healthiest among others. Therefore, traditional rye ginger cakes can be considered as an example of a healthy food that is also relatively stable during long term storage as noted by the small chemical changes observed in its composition. PMID:22980898

  13. Effects of digestate on soil chemical and microbiological properties: A comparative study with compost and vermicompost.

    Science.gov (United States)

    Gómez-Brandón, María; Juárez, Marina Fernández-Delgado; Zangerle, Matthias; Insam, Heribert

    2016-01-25

    Anaerobic digestion has become increasingly popular as an alternative for recycling wastes from different origins. Consequently, biogas residues, most of them with unknown chemical and biological composition, accrue in large quantities and their application into soil has become a widespread agricultural practise. The aim of this study was to evaluate the effects of digestate application on the chemical and microbiological properties of an arable soil in comparison with untreated manure, compost and vermicompost. Once in the soil matrix either the addition of compost or digestate led to an increased nitrification rate, relative to unamended and manure-treated soil, after 15 and 60 days of incubation. Faecal coliform and E. coli colony forming units (CFUs) were not detected in any of the amended soils after 60 days. The highest number of Clostridium perfringens CFUs was recorded in manure-amended soil at the beginning of the experiment and after 15 days; whilst after 60 days the lowest CFU number was registered in digestate-treated soil. Denaturing gradient gel electrophoresis patterns also showed that besides the treatment the date of sampling could have contributed to modifications in the soil ammonia-oxidising bacteria community, thereby indicating that the soil itself may influence the community diversity more strongly than the treatments. PMID:26476314

  14. Solid waste disposal in the soil: effects on the physical, chemical, and organic properties of soil

    Directory of Open Access Journals (Sweden)

    Vanessa Regina Lasaro Mangieri

    2015-04-01

    Full Text Available Currently, there is growing concern over the final destination of the solid waste generated by society. Landfills should not be considered the endpoint for substances contained or generated in solid waste. The sustainable use of natural resources, especially soil and water, has become relevant, given the increase in anthropogenic activities. Agricultural use is an alternative to solid waste (leachate, biosolid disposal, considering the hypothesis that the agricultural use of waste is promising for reducing waste treatment costs, promoting nutrient reuse and improving the physical and chemical conditions of soil. Thus, this literature review, based on previously published data, seeks to confirm or disprove the hypothesis regarding the promising use of solid waste in agriculture to decrease the environmental liability that challenges public administrators in the development of efficient management. The text below addresses the following subtopics after the introduction: current solid waste disposal and environmental issues, the use of solid waste in agriculture, and the effect on the physical and chemical properties of soil and on organic matter, ending with final considerations.

  15. Refinement of the ECETOC approach to identify endocrine disrupting properties of chemicals in ecotoxicology.

    Science.gov (United States)

    Weltje, Lennart; Wheeler, James R; Weyers, Arnd; Galay-Burgos, Malyka

    2013-12-16

    To use and implement an assessment scheme for the evaluation of endocrine disrupting properties of chemicals in ecotoxicology, the types of effect need to be agreed. Effects that merit further consideration in this context should fulfil the following three criteria: caused by an endocrine mode of action, be adverse, and be relevant at the population level to reflect the protection goal of ecotoxicological assessments. Thereafter, a comparison of effect values, regardless of the causative mechanisms, should be made, firstly to determine if endocrine toxicity generates the lowest endpoint within a taxon, and secondly if it is the lowest endpoint compared to that of other taxa living in the same compartment. These comparisons inform on two levels of specificity and determine if endocrine-mediated side-effects determine the ecotoxicological profile of a chemical. Various quantitative measures for the assessment of potency are also presented, which could assist in determining how to handle substances in the risk assessment when a regulatory concern is identified. Finally, derogation criteria should be defined for compounds that were designed as endocrine disruptors for non-vertebrates and those for which there is 'negligible exposure'. This paper discusses and provides proposals on how to apply these concepts for assessment of substances.

  16. Structural, electrical and optical properties of copper selenide thin films deposited by chemical bath deposition technique

    International Nuclear Information System (INIS)

    A low cost chemical bath deposition (CBD) technique has been used for the preparation of Cu2-xSe thin films on glass substrates. Structural, electrical and optical properties of these films were investigated. X-ray diffraction (XRD) study of the Cu2-xSe films annealed at 523K suggests a cubic structure with a lattice constant of 5.697A. Chemical composition was investigated by X-ray photoelectron spectroscopy (XPS). It reveals that absorbed oxygen in the film decreases remarkably on annealing above 423K. The Cu/Se ratio was observed to be the same in as-deposited and annealed films. Both as- deposited and annealed films show very low resistivity in the range of (0.04- 0.15) x 10-5 Ω-m. Transmittance and Reflectance were found in the range of 5-50% and 2-20% respectively. Optical absorption of the films results from free carrier absorption in the near infrared region with absorption coefficient of ∼108 m-1. The band gap for direct transition, Eg.dir varies in the range of 2.0-2.3eV and that for indirect transition Eg.indir is in the range of 1.25-1.5eV.1. (author)

  17. Physico-chemical properties of soil at oil palm plantation area, Labu, Negeri Sembilan

    Science.gov (United States)

    Rozieta, R.; Sahibin A., R.; Wan Mohd Razi, I.

    2015-09-01

    A study on the physico-chemical characteristics of soil from oil palm plantation area at New Labu Estate, Negeri Sembilan was carried out. A number of 20 topsoil (0-20cm) samples were collected based on plantation block by using `Dutch Auger'. The soil physico-chemical properties determined were particle size distribution, organic matter content, pH and total organic carbon. Particle size distribution was determined by pipette method and dry sieving. Bulk density was determined by waxing method. Organic matter and total organic carbon were measured through loss of ignition and Walkley-Black method, respectively. Soil pH was determined based on soil:water ratio of 1:2.5. Results showed that the texture of the soil was classified as sandy clay with the highest percentage of sand particles component. Organic matter content is considered as low at less than 4% and soil organic carbon content was low with 1.75%. The average soil pH in the study area was very acidic with values of 3.81.

  18. [Composition, physico-chemical properties and molecular superstructure of dietary fiber preparations of the cellan type].

    Science.gov (United States)

    Dongowski, G; Frigge, K; Zenke, I

    1995-07-01

    Dietary fiber preparations of "cellan" type were prepared from apples, white cabbage, sugar beet pulp, soy hulls and wheat bran by treatment with amylolytic and proteolytic enzymes as well as by chemical extractions. Scanning electron microscopic examinations show different morphological structures of the preparations and a high maintenance of native biomolecular superstructure. The content of pectin, protein, polysaccharide-hexoses and -pentoses and the composition of monosaccharides (also after their treatment with 4 or 8% sodium hydroxide) were determined. The cellans possess waterbinding capacities (WBC) between 25 g H2O/g and waterholding capacities between 50 g H2O/g. The WBC is related to the internal surface; it diminishes after treatment with NaOH. The interactions between the cellans and the adsorbed water were characterized by NMR-spin-lattice relaxation time T1. The molecular mobility increases as the water content grows. The T1-values of dried cellans decreased with increasing degree of moisture before drying. The supermolecular structure is comparatively disordered. Only in case of soy cellan a crystalline cellulose-I-modification could be identified by X-ray-diffraction pattern, esp. after NaOH treatment. The low degree of order of cellans was observed in the 13C-NMR spectra, too. Only the soy hull preparation resulted in a spectrum corresponding to well-ordered cellulose. The botanic source has an essential influence on the physico-chemical properties of dietary fiber preparations of cellan type.

  19. Variable effects of the internal gelation process in the physical and chemical properties of alumina microspheres

    International Nuclear Information System (INIS)

    Ceramic microspheres have been used in various applications, related to the nuclear, pharmaceutical, chemical, medical, environmental, biotechnology, etc. It is possible to obtain, by internal gelation method, microspheres of different ceramic materials, dense or porous (with controlled porosity) and different sizes. However, the major obstacle is the formation of cracks on drying and/or calcination, which can hinder their use. This study have an objective at the production of alumina (AI2O3) based microspheres by internal gelation process, varying processing parameters in order to control the chemical and physical characteristics such as size, porosity, specific surface area, etc., in addition to specific characteristics that enable their application in filling of the elution columns of 99Mo-99mTc generators. It was developed a simple and efficient method of washing treatment of the microspheres, which enables the extraction of a significant portion of the organic phase present prior to drying and calcination; thus virtually eliminates all cracks that arise during drying, and particularly in calcination step. In addition, process parameters were varied for controlling the porosity and specific surface of the microspheres. Were also characterized in parallel, two transition alumina in the form of powders currently used in filling of elution columns of 99Mo-99mTc generator so as to get an idea of the current requirements for physical properties of the filling material. (author)

  20. Physico-Chemical Properties of the Oils and Fat from Crotalaria cleomifolia Seeds

    International Nuclear Information System (INIS)

    The seeds of C. cleomifolia (locally known as kacang hantu) collected along Simpang Pulai - Berinchang Road, Cameron Highlands, was defatted with hexane and the resulting oil was analysed for their physico-chemical properties. The percentage yield of the oil was calculated as 5.3 %. The acid value (1.2 %), iodine value (85), peroxide value (0.6), saponification value (192.0) and unsaponifiable matter (2.3 %) were determined to assess the quality of the oil. The physico-chemical characterisation showed that C. cleomifolia seeds oil is unsaturated semi-drying oil, with high saponification and acidic values. The fatty acid composition of C. cleomifolia seed oil was determined by Gas Chromatography and Gas Chromatography-Mass Spectrometry (ToF). The seed oil of C. cleomifolia contained linoleic acid (57.59 %) and palmitic acid (5.07 %), the most abundant unsaturated and saturated fatty acids, respectively. The polyunsaturated triacylglycerol (TAG) in C. cleomifolia seed oil determined by reverse phase High performance Liquid Chromatography; contained as PLL (18.04 %) followed by POL + SLL (11.92 %), OOL (7.04 %) and PLLn (6.31 %). The melting and cooling point of the oil were 16.22 degree Celsius and -33.54 degree Celsius, respectively. (author)

  1. Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition

    Directory of Open Access Journals (Sweden)

    K. A. Kamilli

    2013-05-01

    Full Text Available Aerosol hygroscopic growth factors and chemical properties were measured as part of the MEGAPOLI "Megacities Plume Case Study" at the urban site LHVP in the city center of Paris from June to August 2009, and from January to February 2010. Descriptive hygroscopic growth factors (DGF were derived in the diameter range from 25 to 350 nm at relative humidities of 30, 55, 75, and 90% by applying the summation method on humidified and dry aerosol size distributions measured simultaneously with a humidified differential mobility particle sizer (HDMPS and a twin differential mobility particle sizer (TDMPS. For 90% relative humidity, the DGF varied from 1.06 to 1.46 in summer, and from 1.06 to 1.66 in winter. Temporal variations in the observed mean DGF could be well explained with a simple growth model based on the aerosol chemical composition measured by aerosol mass spectrometry (AMS and black carbon photometry (MAAP. In particular, good agreement was observed when sulfate was the predominant inorganic factor. A clear overestimation of the predicted growth factor was found when the nitrate mass concentration exceeded values of 10 μg m3, e.g. during winter.

  2. Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition

    Science.gov (United States)

    Kamilli, K. A.; Poulain, L.; Held, A.; Nowak, A.; Birmili, W.; Wiedensohler, A.

    2014-01-01

    Aerosol hygroscopic growth factors and chemical properties were measured as part of the MEGAPOLI "Megacities Plume Case Study" at the urban site Laboratoire d'Hygiène de la Ville de Paris (LHVP) in the city center of Paris from June to August 2009, and from January to February 2010. Descriptive hygroscopic growth factors (DGF) were derived in the diameter range from 25 to 350 nm at relative humidities of 30, 55, 75, and 90% by applying the summation method on humidified and dry aerosol size distributions measured simultaneously with a humidified differential mobility particle sizer (HDMPS) and a twin differential mobility particle sizer (TDMPS). For 90% relative humidity, the DGF varied from 1.06 to 1.46 in summer, and from 1.06 to 1.66 in winter. Temporal variations in the observed mean DGF could be well explained with a simple growth model based on the aerosol chemical composition measured by aerosol mass spectrometry (AMS) and black carbon photometry (MAAP). In particular, good agreement was observed when sulfate was the predominant inorganic factor. A clear overestimation of the predicted growth factor was found when the nitrate mass concentration exceeded values of 10 μg m-3, e.g., during winter.

  3. Correlations between Optical, Chemical and Physical Properties ofBiomass Burn Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, Rebecca J.; Lewis, K.; Desyaterik, Yury; Wang, Z.; Tivanski, Alexei V.; Arnott, W.P.; Laskin, Alexander; Gilles, M.K.

    2008-01-29

    Aerosols generated from burning different plant fuels were characterized to determine relationships between chemical, optical and physical properties. Single scattering albedo ({omega}) and Angstrom absorption coefficients ({alpha}{sub ap}) were measured using a photoacoustic technique combined with a reciprocal nephelometer. Carbon-to-oxygen atomic ratios, sp{sup 2} hybridization, elemental composition and morphology of individual particles were measured using scanning transmission X-ray microscopy coupled with near-edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS) and scanning electron microscopy with energy dispersion of X-rays (SEM/EDX). Particles were grouped into three categories based on sp2 hybridization and chemical composition. Measured {omega} (0.4-1.0 at 405 nm) and {alpha}{sub ap} (1.0-3.5) values displayed a fuel dependence. The category with sp{sup 2} hybridization >80% had values of {omega} (<0.5) and {alpha}{sub ap} ({approx}1.25) characteristic of light absorbing soot. Other categories with lower sp2 hybridization (20 to 60%) exhibited higher {omega} (>0.8) and {alpha}{sub ap} (1.0 to 3.5) values, indicating increased absorption spectral selectivity.

  4. Chemical characterization and immunomodulatory properties of polysaccharides isolated from probiotic Lactobacillus casei LOCK 0919

    Science.gov (United States)

    Górska, Sabina; Hermanova, Petra; Ciekot, Jarosław; Schwarzer, Martin; Srutkova, Dagmar; Brzozowska, Ewa; Kozakova, Hana; Gamian, Andrzej

    2016-01-01

    The Lactobacillus casei strain, LOCK 0919, is intended for the dietary management of food allergies and atopic dermatitis (LATOPIC® BIOMED). The use of a probiotic to modulate immune responses is an interesting strategy for solving imbalance problems of gut microflora that may lead to various disorders. However, the exact bacterial signaling mechanisms underlying such modulations are still far from being understood. Here, we investigated variations in the chemical compositions and immunomodulatory properties of the polysaccharides (PS), L919/A and L919/B, which are produced by L. casei LOCK 0919. By virtue of their chemical features, such PS can modulate the immune responses to third-party antigens. Our results revealed that L919/A and L919/B could both modulate the immune response to Lactobacillus planatarum WCFS1, but only L919/B could alter the response of THP-1 cells (in terms of tumor necrosis factor alpha production) to L. planatarum WCFS1 and Escherichia coli Nissle 1917. The comprehensive immunochemical characterization is crucial for the understanding of the biological function as well as of the bacteria–host and bacteria–bacteria cross-talk. PMID:27102285

  5. Hydraulic Conductivity Functions in Relation to Some Chemical Properties in a Cultivated Oxisols of a Humid Region, Delta State, Nigeria

    Directory of Open Access Journals (Sweden)

    Egbuchua, C. N.

    2014-04-01

    Full Text Available The study was conducted to evaluate hydraulic conductivity functions in relation to some soil chemical properties in an oxisols of the tropics. Field and laboratory studies were carried out and data collected, subjected to statistical analytical procedure for computing coefficient of variability and correlation among soil properties. Results of the study showed that hydraulic conductivity functions varied spatially and temporarily across the experimental points with a moderate mean value of 0.0026 cm/h and a coefficient o variation of 31.45% soil chemical properties showed that the soils were acidic with a mean pH value of 5.12. Organic carbon, total nitrogen and available phosphorus were low with mean values of 1.29%, 0.68% and 4.43 mgkg-1. Coefficient of variability among soil properties indicated less to moderately variable. Soil pH had negative correlation with all the soil properties evaluated.

  6. Bioactivity, physical and chemical properties of MTA mixed with propylene glycol

    Directory of Open Access Journals (Sweden)

    Vaishali Prakash NATU

    2015-08-01

    Full Text Available AbstractObjective To investigate the physical (setting time, hardness, flowability, microstructure and chemical (pH change, calcium release, crystallinity properties and the biological outcomes (cell survival and differentiation of mineral trioxide aggregate (MTA mixed using different proportions of propylene glycol (PG and water.Material and Methods White MTA was mixed with different water/PG ratios (100/0, 80/20 and 50/50. Composition (XRD, microstructure (SEM, setting time (ASTM C266-13, flowability (ANSI/ADA 57-2000, Knoop hardness (100 g/10 s and chemical characteristics (pH change and Ca2+ release for 7 days were evaluated. Cell proliferation, osteo/odontoblastic gene expression and mineralization induced by MTA mixed with PG were evaluated. MTA discs (5 mm in diameter, 2 mm thick were prepared and soaked in culture medium for 7 days. Next, the discs were removed and the medium used to culture dental pulp stem cells (DPSC for 28 days. Cells survival was evaluated using MTS assay (24, 72 and 120 h and differentiation with RT-PCR (ALP, OCN, Runx2, DSPP and MEPE and alizarin red staining (7 and 14 days. Data were analysed using one-way ANOVA and Tukey’s post-hoc analysis (a=0.05.Results The addition of PG significantly increased setting time, flowability and Ca2+ release, but it compromised the hardness of the material. SEM showed that 50/50 group resulted porous material after setting due to the incomplete setting reaction, as shown by XRD analysis. The addition of PG (80/20 and 50/50 was not capable to improve cell proliferation or to enhance gene expression, and mineralized deposition of DPSC after 7 and 14 days as compared to the 100/0.Conclusion Except for flowability, the addition of PG did not promote further improvements on the chemical and physical properties evaluated, and it was not capable of enhancing the bioactivity of the MTA.

  7. Effects of chemical alteration on fracture mechanical properties in hydrothermal systems

    Science.gov (United States)

    Callahan, O. A.; Eichhubl, P.; Olson, J. E.

    2015-12-01

    Fault and fracture networks often control the distribution of fluids and heat in hydrothermal and epithermal systems, and in related geothermal and mineral resources. Additional chemical influences on conduit evolution are well documented, with dissolution and precipitation of mineral species potentially changing the permeability of fault-facture networks. Less well understood are the impacts of chemical alteration on the mechanical properties governing fracture growth and fracture network geometry. We use double-torsion (DT) load relaxation tests under ambient air conditions to measure the mode-I fracture toughness (KIC) and subcritical fracture growth index (SCI) of variably altered rock samples obtained from outcrop in Dixie Valley, NV. Samples from southern Dixie Valley include 1) weakly altered granite, characterized by minor sericite in plagioclase, albitization and vacuolization of feldspars, and incomplete replacement of biotite with chlorite, and 2) granite from an area of locally intense propylitic alteration with chlorite-calcite-hematite-epidote assemblages. We also evaluated samples of completely silicified gabbro obtained from the Dixie Comstock epithermal gold deposit. In the weakly altered granite KIC and SCI are 1.3 ±0.2 MPam1/2 (n=8) and 59 ±25 (n=29), respectively. In the propylitic assemblage KIC is reduced to 0.6 ±0.1 MPam1/2 (n=11), and the SCI increased to 75 ±36 (n = 33). In both cases, the altered materials have lower fracture toughness and higher SCI than is reported for common geomechanical standards such as Westerly Granite (KIC ~1.7 MPam1/2; SCI ~48). Preliminary analysis of the silicified gabbro shows a significant increase in fracture toughness, 3.6 ±0.4 MPam1/2 (n=2), and SCI, 102 ±45 (n=19), compared to published values for gabbro (2.9 MPam1/2 and SCI = 32). These results suggest that mineralogical and textural changes associated with different alteration assemblages may result in spatially variable rates of fracture

  8. Physical chemical properties of sludges of a chemical treatment of boilers feed water and ways of their utilization

    Directory of Open Access Journals (Sweden)

    T. Krasnenko

    2013-03-01

    Full Text Available Water is a necessary process for TPP power plant operation. To the power station, in the production of electricity and heat as a result of the preparation of large amounts of water to compensate for losses associated with the release of process steam for production, produce large quantities of waste water treatment - water treatment chemical sludge (WTCS.

  9. Effects of particle size distribution on some physical, chemical and functional properties of unripe banana flour.

    Science.gov (United States)

    Savlak, Nazlı; Türker, Burcu; Yeşilkanat, Nazlıcan

    2016-12-15

    The objective of this study was to examine the effect of particle size distribution on physical, chemical and functional properties of unripe banana flour for the first time. A pure triploid (AAA group) of Musa acuminata subgroup Cavendish (°Brix;0.2, pH;4.73, titratable acidity; 0.56g/100g malic acid, total solids; 27.42%) which was supplied from Gazipaşa, Antalya, Turkey from October 2014 to October 2015 was used. Size fractions of physical, functional and antioxidant properties. Particle size significantly effected color, water absorbtion index and wettability. L(∗) value decreased, a(∗) and b(∗) values decreased by increasing particle size (r(2)=-0.94, r(2)=0.72, r(2)=0.73 respectively). Particles under 212μm had the lowest rate of wettability (83.40s). A negative correlation between particle size and wettability (r(2)=-0.75) and positive correlation between particle size and water absorption index (r(2)=0.94) was observed.

  10. The Effect of Egg Yolk Oil on The Chemical, Physical and Sensory Properties of Mayonnaise

    Directory of Open Access Journals (Sweden)

    Kovalcuks Aleksandrs

    2016-06-01

    Full Text Available Egg yolk oil (EYO is an essence of egg bioactive compounds. Extracted from egg yolk it can be used in various food products increasing their nutritional and biological value. Mayonnaise is a kind of a semi-solid oil-inwater emulsion containing 60-80% fat. Mayonnaise typically contains oil, egg yolk, vinegar, salt, sugar and thickening agents. Mayonnaise is the product where application of EYO can be evaluated. The aim of this study was to evaluate the effect of egg yolk oil on the chemical, physical and sensory properties of mayonnaise. EYO was added to mayonnaise in the concentrations of 1, 3, 5 and 7%. The main parameters of mayonnaise were determined using standard methods: lipid, protein, fatty acids, vitamin D, pH, viscosity, colour and acceptance of sensory properties (viscosity, egg aroma, egg taste, yellow colour, sour taste and creaminess. At analyzed concentrations EYO has no influence (p > 0.05 on mayonnaise pH, lipid and protein content, but an increase in EYO content decreases the viscosity of mayonnaise. Increasing amount of EYO additive resulted in more intensive yellow colour of mayonnaise. Additions of EYO enrich mayonnaise with vitamin D and docosahexaenoic acid. Sensory evaluation of mayonnaise samples showed panellists’ preference for mayonnaise with 3% and 5% EYO additive.

  11. Recent progress in understanding physical and chemical properties of mineral dust

    Directory of Open Access Journals (Sweden)

    P. Formenti

    2010-12-01

    Full Text Available This paper presents a review of recently acquired knowledge of the physico-chemical properties of mineral dust from Africa and Asia based on data and discussion during the Third International Dust Workshop, held in Leipzig (Germany in September 2008. Various regional experiments have been conducted in the last few years, mostly close to source regions or after short-range transport. Significant progress has been made in characterising the mineralogy of iron and the description of particle shape close to source regions. We consider that future research should focus on the evolution of dust properties during transport. In particular, the prediction of the characteristics of the size distribution of mineral dust at emission and their dynamics evolution during transport should be considered as a high-priority. The presence of large airborne particles above 20 μm in diameter, suggested by various studies, has limited implication for radiation, but should be important for deposition-based studies such as those on ocean productivity. Modelling the uplifting and transport of such large particles will represent a new serious challenge for transport models. A critical assessment and standardisation of the experimental and analytical methods is recommended.

  12. Chemical, biochemical, and microbiological properties of soils from abandoned and extensively cultivated olive orchards.

    Science.gov (United States)

    Palese, A M; Magno, R; Casacchia, T; Curci, M; Baronti, S; Miglietta, F; Crecchio, C; Xiloyannis, C; Sofo, A

    2013-01-01

    The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical, and microbiological properties in a soil of a southern olive grove abandoned for 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization). Soil organic matter, total nitrogen, and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, inter alia, increased the number of cellulolytic bacteria and stimulated the activity of β -glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means of the Biolog method, as a result of a sort of specialization trend towards low quality organic substrates. From this point of view, the extensive cultivation management seemed to not induce a disturbance to microbiological communities.

  13. Effects of Sorghum Flour Addition on Chemical and Rheological Properties of Hard White Winter Wheat

    Directory of Open Access Journals (Sweden)

    Ranya F. Abdelghafor

    2013-11-01

    Full Text Available This study was carried out to investigate the chemical and rheological properties of different blends prepared using hard white winter wheat (HWWW; Triticum aestivum Desf. and whole or decorticated sorghum (Sorghum bicolor. Whole and decorticated sorghum were used to replace 5, 10, 15 and 20% of wheat flour. Wheat samples had higher protein, moisture and calcium values and lower fat, ash, carbohydrates, iron and phosphorous values compared to whole and decorticated sorghum flours. Decortication of sorghum grains decreased moisture, ash, fat, crude protein, iron and phosphorous content, but increased carbohydrate content. Farinogram properties such as dough water absorption, development time and stability and Farinograph quality number decreased as the amount of substituted sorghum increased; whereas mixing tolerance index increased. Moreover, at fixed gluten levels, as sorghum flour increased in the blend, wet gluten, dry gluten and gluten index decreased. Increasing sorghum in the blend also decreased energy, resistance to extension and extensibility of the dough, but contributed to an increase in the ratio of resistance to extensibility. Furthermore, as fermentation time increased, energy, resistance to extension and the ratio number of energy to extension increased, whereas extensibility decreased.

  14. Chemical, Biochemical, and Microbiological Properties of Soils from Abandoned and Extensively Cultivated Olive Orchards

    Directory of Open Access Journals (Sweden)

    A. M. Palese

    2013-01-01

    Full Text Available The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical, and microbiological properties in a soil of a southern olive grove abandoned for 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization. Soil organic matter, total nitrogen, and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, inter alia, increased the number of cellulolytic bacteria and stimulated the activity of β-glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means of the Biolog method, as a result of a sort of specialization trend towards low quality organic substrates. From this point of view, the extensive cultivation management seemed to not induce a disturbance to microbiological communities.

  15. Physico-chemical properties and amino acid profiles of sap from Tunisian date palm

    Directory of Open Access Journals (Sweden)

    Ines Makhlouf-Gafsi

    2016-02-01

    Full Text Available ABSTRACT Date palm sap (Phoenix dactylifera L., also known as “legmi”, is a fresh juice extracted from date palm trees. The present study aimed to elucidate the effects of collection time (at the beginning of the tapping period and after seven days of collection on the amino acid profile and physico-chemical properties of date palm sap from both male and female trees. Dry matter, protein, amino acid, and sugar profiles were determined using the Kjeldahl method, High-Performance Liquid Chromatography (HPLC, and High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection (HPAEC-PAD, respectively. Date palm sap from both male and female trees contained high levels of carbohydrates. HPLC analysis showed that this fraction was dominated by sucrose in the sap sample from female trees compared to that from male trees. Male date palm sap was noted to exhibit lower dry matter content than female date palm sap but higher protein, total polyphenol, ash, and amino acid contents. While the major essential amino acids in the sap from male trees consisted of valine and threonine, they were represented by lysine and phenylalanine in sap samples from female trees. Further, Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE analysis showed the presence of a proteinic band of 30 kDa only for the sap from male trees. Taken together, the sap from both male and female date palm trees had a number of properties that are highly valued by the functional food industry.

  16. Effect of gamma irradiation on microbiological, chemical, and sensory properties of fresh ashitaba and kale juices

    Science.gov (United States)

    Jo, Cheorun; Ahn, Dong Uk; Lee, Kyung Haeng

    2012-08-01

    Due to the popularity of health effects upon intake of fresh fruits and vegetables, the demand for fresh vegetables and fruit juices has rapidly increased. However, currently, washing is the only procedure for reducing contaminated microorganisms, which obviously limits the shelf-life of fresh vegetable juice (less than 3 days). In this study, we examined the effects of irradiation on the microbiological, chemical and sensory properties of ashitaba and kale juices for industrial application and possible shelf-life extension. Freshly made ashitaba and kale juices already had 2.3×105 and 9.5×104 CFU/mL, respectively. Irradiation of 5 kGy induced higher than 2 decimal reductions in the microbial level, which was consistently maintained during storage for 7 days under refrigerated conditions. Total content of ascorbic acid in vegetable juice decreased upon irradiation in a dose-dependent manner. However, the content of flavonoids did not change, whereas that of polyphenols increased upon irradiation. In sensory evaluation, the ashitaba and kale juices without irradiation (control) scored lower than the irradiated samples after 1 and 3 days, respectively. This study confirms that irradiation is an effective method for sterilizing fresh vegetable juice without compromising sensory property, which cannot be subjected to heat pasteurization due to changes in the bioactivities of the products.

  17. COMPARISON OF THE PHYSICAL AND CHEMICAL PROPERTIES OF THE DISPERSIVE AND SODIC SOILS

    Directory of Open Access Journals (Sweden)

    G. NAGY

    2016-03-01

    Full Text Available Some cohesive soils show very little resistance when it comes to interaction with relatively pure water, however the water flow itself does not have to necessarily cause any damage in the soil structure. These soils are so poorly bonded, that this small amount of water flow can lead to structural breakdown. The effect caused several dike and earth dam damages and failures in the past years, therefore the behavior itself is considered as a geotechnical risk in the process of design. The dike breaches lead to the emergence of knowing how to identify and locate the areas and soil types, where the hazardous soils occur. In geotechnical engineering these soils are referred as dispersive soils, and their properties are known since the 1960s. In the recent years researches were carried out to get a better point of view of the reasons of these kind of behavior. Therefore the investigation of physical and chemical properties were made. The results showed that the dispersive behavior can be connected with the amount of dissolved salts in the soil extract. Since these are known as the origin of sodic soils, the relationship was investigated.

  18. Effects of particle size distribution on some physical, chemical and functional properties of unripe banana flour.

    Science.gov (United States)

    Savlak, Nazlı; Türker, Burcu; Yeşilkanat, Nazlıcan

    2016-12-15

    The objective of this study was to examine the effect of particle size distribution on physical, chemical and functional properties of unripe banana flour for the first time. A pure triploid (AAA group) of Musa acuminata subgroup Cavendish (°Brix;0.2, pH;4.73, titratable acidity; 0.56g/100g malic acid, total solids; 27.42%) which was supplied from Gazipaşa, Antalya, Turkey from October 2014 to October 2015 was used. Size fractions of <212, 212-315, 316-500 and 501-700μm were characterized for their physical, functional and antioxidant properties. Particle size significantly effected color, water absorbtion index and wettability. L(∗) value decreased, a(∗) and b(∗) values decreased by increasing particle size (r(2)=-0.94, r(2)=0.72, r(2)=0.73 respectively). Particles under 212μm had the lowest rate of wettability (83.40s). A negative correlation between particle size and wettability (r(2)=-0.75) and positive correlation between particle size and water absorption index (r(2)=0.94) was observed. PMID:27451170

  19. Review of chemical and radio toxicological properties of polonium for internal contamination purposes

    International Nuclear Information System (INIS)

    The discovery of polonium (Po) was first published in July, 1898 by P. Curie and M. Curie. It was the first element to be discovered by the radiochemical method. Polonium can be considered as a famous but neglected element: only a few studies of polonium chemistry have been published, mostly between 1950 and 1990. The recent (2006) event in which Po-210 evidently was used as a poison to kill A. Litvinenko has raised new interest in polonium. 2011 being the 100. anniversary of the Marie Curie Nobel Prize in Chemistry, the aim of this review is to look at the several aspects of polonium linked to its chemical properties and its radiotoxicity, including (i) its radiochemistry and interaction with matter; (ii) its main sources and uses; (iii) its physicochemical properties; (iv) its main analytical methods; (v) its background exposure risk in water, food, and other environmental media; (vi) its biokinetics and distribution following inhalation, ingestion, and wound contamination; (vii) its dosimetry; and (viii) treatments available (decorporation) in case of internal contamination. (authors)

  20. Effect of chemical admixtures on properties of high-calcium fly ash geopolymer

    Science.gov (United States)

    Rattanasak, Ubolluk; Pankhet, Kanokwan; Chindaprasirt, Prinya

    2011-06-01

    Owing to the high viscosity of sodium silicate solution, fly ash geopolymer has the problems of low workability and rapid setting time. Therefore, the effect of chemical admixtures on the properties of fly ash geopolymer was studied to overcome the rapid set of the geopolymer in this paper. High-calcium fly ash and alkaline solution were used as starting materials to synthesize the geopolymer. Calcium chloride, calcium sulfate, sodium sulfate, and sucrose at dosages of 1wt% and 2wt% of fly ash were selected as admixtures based on concrete knowledge to improve the properties of the geopolymer. The setting time, compressive strength, and degree of reaction were recorded, and the microstructure was examined. The results show that calcium chloride significantly shortens both the initial and final setting times of the geopolymer paste. In addition, sucrose also delays the final setting time significantly. The degrees of reaction of fly ash in the geopolymer paste with the admixtures are all higher than those of the control paste. This contributes to the obvious increases in compressive strength.

  1. The physical and chemical properties of the polyvinylalcohol/polyvinylpyrrolidone/hydroxyapatite composite hydrogel.

    Science.gov (United States)

    Ma, Yahui; Bai, Tongchun; Wang, Fei

    2016-02-01

    A hydrogel of polyvinylalcohol (PVA)/polyvinylpyrrolidone (PVP)/hydroxyapatite (HA) was prepared by a repeated freezing and thawing technique. The effect of HA on the hydrogel was evaluated by comparing the physical and chemical properties of PVA/PVP/HA and PVA/PVP hydrogels. By using theoretical models, the information about the swelling kinetics and the dehydration kinetics have been obtained. From the analysis of structure, mechanical properties, and molecular interaction, the application of PVA/PVP/HA hydrogel as a biomaterial has been evaluated. Relative to PVA/PVP, the PVA/PVP/HA hydrogel is of denser network structure, lower water content, larger storage modulus, and higher dehydration activation energy. These results reveal that, as HA fills in the hydrogel, the molecular interaction is enhanced, the free space of network is compressed, and the diffusion activation energy of water is increased. In spite of its water content being decreased, it is still in the range of meeting the requirement of bio-application. When the hydrogel is subjected to external forces, the matrix will transfer the load to the HA powder, thus enhance the strength of the hydrogel. For application in bio-materials, HA will still have osteoinductivity because its crystalline structure is not interrupted in PVA/PVP/HA hydrogel environment.

  2. Microbiological and chemical properties of litter from different chicken types and production systems

    Energy Technology Data Exchange (ETDEWEB)

    Omeira, N. [Department of Land and Water Resources, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon); Barbour, E.K. [Department of Animal Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon)]. E-mail: eb01@aub.edu.lb; Nehme, P.A. [Department of Land and Water Resources, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon); Hamadeh, S.K. [Department of Animal Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon); Zurayk, R. [Department of Land and Water Resources, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon); Bashour, I. [Department of Land and Water Resources, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut (Lebanon)

    2006-08-15

    Chicken litter is produced in large quantities from all types of poultry raising activities. It is primarily used for land application, thus it is essential to analyze its properties before it is released to the environment. The objective of this study is to compare the microbiological and chemical properties of litter generated from layer and broiler chickens reared under intensive and free-range production systems. The microbiological analysis consisted of the enumeration of total bacteria, total coliforms, Staphylococcus species, Salmonella species and Clostridium perfringens. Chicken litter from layers reared under intensive and free range systems showed lower mean total bacterial count than the litter collected from chicken broilers reared under either of the two systems (P = 0.0291). The litter from intensive layers had the lowest mean total coliform counts (P = 0.0222) while the lowest Staphylococcus species count was observed in the litter from free-range layers (P = 0.0077). The C. perfringens count was the lowest in chicken litter from intensively raised broilers and layers (P = 0.0001). The chemical properties of litter from the different chicken types and production systems were compared based on determination of pH, electrical conductivity, carbon, nitrogen, phosphorus, potassium, cadmium and zinc. Litter from free-range broilers showed the highest pH value (P = 0.0005); however, the electrical conductivity was higher in the litter from both intensive and free-range layers compared to the litter from both broiler production systems (P = 0.0117). Chicken litter from intensive systems had higher nitrogen content than litter from free-range systems (P = 0.0000). The total phosphorus was the lowest in free-range broiler litter (P = 0.0001), while the total potassium was the lowest in litter from intensively managed broilers (P = 0.0000). Zinc appeared higher in litter from layers compared to that from broilers (P = 0.0101). The cadmium content was higher

  3. The effect of finite temperature and chemical potential on nucleon properties in the logarithmic quark sigma model

    Science.gov (United States)

    Abu-Shady, M.; Abu-Nab, A.

    2015-12-01

    The logarithmic quark sigma model is applied to study the nucleon properties at finite temperature and chemical potential. The field equations have been solved numerically in the mean-field approximation by using the extended iteration method at finite temperature and baryon chemical potential. Baryon properties are investigated, such as the hedgehog mass, the magnetic moments of the proton and neutron, and the pion-nucleon coupling constant. We find that the hedgehog mass and the magnetic moments of the proton and neutron increase with increasing temperature and chemical potential, while the pion-nucleon coupling constant decreases. A comparison with the original sigma model and QCD sum rules is presented. We conclude that the logarithmic quark sigma model successfully describes baryon properties of a hot and dense medium.

  4. THE INFLUENCE OF THE COMPLEX CHEMICAL ADDITIVE CONTAINING THE STRUCTURED CARBON NANOMATERIAL ON PROPERTIES OF CEMENT

    Directory of Open Access Journals (Sweden)

    O. Yu. Sheyda

    2015-01-01

    Full Text Available The paper presents results of investigations on influence of domestic complex chemical additive containing structured carbon nanomaterial and characterized by a combination effect (curing acceleration and plasticizing on cement and cement stone properties. The purpose of the investigations, on the one hand, has been to confirm efficacy of УКД-1additive from the perspective for increasing the rate of gain, strength growth of cement concrete and additive influence on setting time with the purpose to preserve molding properties of concrete mixes in time, and on the other hand, that is to assess “mechanism” of the УКД-1 additive action in the cement concrete. The research results have revealed regularities in changes due to the additive of water requirements and time period of the cement setting. The reqularities are considered as a pre-requisite for relevant changes in molding properties of the concrete mixes. The paper also experimentally substantiates the possibility to decrease temperature of cement concrete heating with the УДК-1 additive. It has been done with the purpose to save energy resources under production conditions. In addition to this the paper proves the efficiency of the additive which is expressed in strength increase of cement stone up to 20–40 % in the rated age (28 days that is considered as a basis for strength growth of cement concrete. The paper confirms a hypothesis on physical nature of this phenomenon because the X-ray phase analysis method has shown that there are no changes in morphology of portland cement hydration products under the action of the additive agent containing a structured carbon nanomaterial. Results of theoretical and experimental investigations on УКД-1 additive efficiency have been proved by industrial approbation while fabricating precast concrete products and construction of monolithic structures under plant industrial conditions (Minsk, SS “Stroyprogress” JSC MAPID and on

  5. Effect of gamma irradiation on microbiological, chemical, and sensory properties of fresh ashitaba and kale juices

    International Nuclear Information System (INIS)

    Due to the popularity of health effects upon intake of fresh fruits and vegetables, the demand for fresh vegetables and fruit juices has rapidly increased. However, currently, washing is the only procedure for reducing contaminated microorganisms, which obviously limits the shelf-life of fresh vegetable juice (less than 3 days). In this study, we examined the effects of irradiation on the microbiological, chemical and sensory properties of ashitaba and kale juices for industrial application and possible shelf-life extension. Freshly made ashitaba and kale juices already had 2.3×105 and 9.5×104 CFU/mL, respectively. Irradiation of 5 kGy induced higher than 2 decimal reductions in the microbial level, which was consistently maintained during storage for 7 days under refrigerated conditions. Total content of ascorbic acid in vegetable juice decreased upon irradiation in a dose-dependent manner. However, the content of flavonoids did not change, whereas that of polyphenols increased upon irradiation. In sensory evaluation, the ashitaba and kale juices without irradiation (control) scored lower than the irradiated samples after 1 and 3 days, respectively. This study confirms that irradiation is an effective method for sterilizing fresh vegetable juice without compromising sensory property, which cannot be subjected to heat pasteurization due to changes in the bioactivities of the products. - Highlights: ► We examined the effects of irradiation of fresh vegetable juices (ashitaba and kale) for industrial application. ► Irradiation of 5 kGy induced higher than 2 decimal reductions in the microbial level. ► Ascorbic acid in vegetable juice decreased upon irradiation in a dose-dependent manner. ► Content of flavonoids did not change whereas that of polyphenols increased. ► There was no change in sensory properties after irradiation.

  6. Influence of land cover changes on the physical and chemical properties of alpine meadow soil

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Taking the alpine cold meadow grassland in the southeastern part of the Qinghai-Tibetan Plateau as an example, this research deals with the characteristics of alpine meadow soil property changes, including soil nutrients, soil physical properties and soil moisture content under different land coverage conditions. With the degradation of grassland vegetation and the decline of vegetation coverage, soil compactness reduces, gravel content increases and bulk density increases. The originally dense root-system layer is gradually denuded, making the soil coarse and gravel. The change of the organic matter contents with the vegetation coverage change in the surface soil layer (0-20 cm) has shown an obvious cubic polynomial curve process. The organic matter contents increase rapidly when land coverage is above 60%, contrarily decreases on a large scale when land coverage is below 30%. Between 30%-60% of land coverage the organic matter contents remain stable. The total N and organic matter contents in soil have shown quite similar change regularity. Following this the mathematic equations are derived to describe such change processes. Moisture content in soil changes sharply with the vegetation coverage change. Soil moisture content change with the vegetation coverage change has shown a quadratic parabola process. Results have shown that organic matter content and the total N content of the alpine meadow soil decrease by 14890 kg/hm2 and 5505 kg/hm2 respectively as the vegetation coverage reduces from 90% to less than 30%. The heavy changes of soil physical and chemical properties with grassland degradation have made the recovery of alpine meadow ecological system impossible. The protection of alpine meadow vegetation is of vital importance to the maintenance of the regional soil environment and the regional ecological system.

  7. Properties of NiO thin films deposited by chemical spray pyrolysis using different precursor solutions

    Energy Technology Data Exchange (ETDEWEB)

    Cattin, L. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes F-44000 (France); Reguig, B.A.; Khelil, A. [Universite d' Oran Es-Senia, LPCM2E (Algeria); Morsli, M. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes F-44000 (France); Benchouk, K. [Universite d' Oran Es-Senia, LPCM2E (Algeria); Bernede, J.C. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes F-44000 (France)], E-mail: Jean-Christian.Bernede@univ-nantes.fr

    2008-07-15

    NiO thin films have been deposited by chemical spray pyrolysis using a perfume atomizer to grow the aerosol. The influence of the precursor, nickel chloride hexahydrate (NiCl{sub 2}.6H{sub 2}O), nickel nitrate hexahydrate (Ni(NO{sub 3}){sub 2}.6H{sub 2}O), nickel hydroxide hexahydrate (Ni(OH){sub 2}.6H{sub 2}O), nickel sulfate tetrahydrate (NiSO{sub 4}.4H{sub 2}O), on the thin films properties has been studied. In the experimental conditions used (substrate temperature 350 deg. C, precursor concentration 0.2-0.3 M, etc.), pure NiO thin films crystallized in the cubic phase can be achieved only with NiCl{sub 2} and Ni(NO{sub 3}){sub 2} precursors. These films have been post-annealed at 425 deg. C for 3 h either in room atmosphere or under vacuum. If all the films are p-type, it is shown that the NiO films conductivity and optical transmittance depend on annealing process. The properties of the NiO thin films annealed under room atmosphere are not significantly modified, which is attributed to the fact that the temperature and the environment of this annealing is not very different from the experimental conditions during spray deposition. The annealing under vacuum is more efficient. This annealing being proceeded in a vacuum no better than 10{sup -2} Pa, it is supposed that the modifications of the NiO thin film properties, mainly the conductivity and optical transmission, are related to some interaction between residual oxygen and the films.

  8. Biomass burning aerosol over the Amazon during SAMBBA: impact of chemical composition on radiative properties

    Science.gov (United States)

    Morgan, William; Allan, James; Flynn, Michael; Darbyshire, Eoghan; Hodgson, Amy; Liu, Dantong; O'shea, Sebastian; Bauguitte, Stephane; Szpek, Kate; Langridge, Justin; Johnson, Ben; Haywood, Jim; Longo, Karla; Artaxo, Paulo; Coe, Hugh

    2014-05-01

    Biomass burning represents one of the largest sources of particulate matter to the atmosphere, resulting in a significant perturbation to the Earth's radiative balance coupled with serious impacts on public health. Globally, biomass burning aerosols are thought to exert a small warming effect but with the uncertainty being 4 times greater than the central estimate. On regional scales, the impact is substantially greater, particularly in areas such as the Amazon Basin where large, intense and frequent burning occurs on an annual basis for several months. Absorption by atmospheric aerosols is underestimated by models over South America, which points to significant uncertainties relating to Black Carbon (BC) aerosol properties. Initial results from the South American Biomass Burning Analysis (SAMBBA) field experiment, which took place during September and October 2012 over Brazil on-board the UK Facility for Airborne Atmospheric Measurement (FAAM) BAe-146 research aircraft, are presented here. Aerosol chemical composition was measured by an Aerodyne Aerosol Mass Spectrometer (AMS) and a DMT Single Particle Soot Photometer (SP2). The physical, chemical and optical properties of the aerosols across the region will be characterized in order to establish the impact of biomass burning on regional air quality, weather and climate. The aircraft sampled a range of conditions including sampling of pristine Rainforest, fresh biomass burning plumes, regional haze and elevated biomass burning layers within the free troposphere. The aircraft sampled biomass burning aerosol across the southern Amazon in the states of Rondonia and Mato Grosso, as well as in a Cerrado (Savannah-like) region in Tocantins state. This presented a range of fire conditions, both in terms of their number, intensity, vegetation-type and their combustion efficiencies. Near-source sampling of fires in Rainforest environments suggested that smouldering combustion dominated, while flaming combustion dominated

  9. Effect of Azolla Based - Organic Fertilizer, Rock Phosphate and Rice Hull Ash on Rice Yield and Chemical Properties of Alfisols

    OpenAIRE

    Sudadi; Sumarno; Wiki Handi

    2014-01-01

    The application of chemical fertilizer for long time may adverse soil environment. Organic agriculture, for example combination use of azolla based-organic fertilizer, phosphate rock and rice hull ash, was one of ways that able to recover it. Research was conducted in Sukosari, Jumantono, Karanganyar while soi chemical properties analysis was analysed in Soil Chemistry and Fertility Laboratory, Fac. of Agriculture, Sebelas Maret University April to November 2013. Research design used was R...

  10. Storage stability of margarines produced from enzymatically interesterified fats compared to those prepared by conventional methods - Chemical properties

    DEFF Research Database (Denmark)

    Zhang, Hong; Jacobsen, Charlotte; Pedersen, Lars Saaby;

    2006-01-01

    In this study, four margarine hardstocks were produced, two from enzymatically interesterified fats at 80 and 100% conversion, one from chemically randomized fat and one from physically mixed fat. These four hardstocks, blended with 50% sunflower oil, were mainly used for the production of table......) and to selected commercial margarines. The changes in the chemical properties of the products, including peroxide values (PV), tocopherols, free fatty acids, volatile oxidation products, and sensory evaluation, were examined during storage. It was observed that the margarine produced from the chemically...

  11. Sensory and rheological properties of transgenically and chemically modified starch ingredients as evaluated in a food product model

    DEFF Research Database (Denmark)

    Ahmt, T.; Wischmann, Bente; Blennow, A.;

    2004-01-01

    gels with a higher tendency to retrograde and a low freeze/thaw stability as compared to starches with shorter amylopectin chains and lower phosphorous content. The textural properties of the food product model prepared from genetically and chemically modified starches were characterised by sensory......Starches derived from five genetically modified potato lines, two chemically modified potato starches and two native starches from potato and maize were subjected to physical and chemical analyses and their functionality evaluated in a milk-based food product model. The transgenic starches were...

  12. Impact of chemical treatments on the mechanical and water absorption properties of coconut fibre (Cocos nucifera reinforced polypropylene composites

    Directory of Open Access Journals (Sweden)

    Isiaka O. OLADELE

    2016-07-01

    Full Text Available In this work, chemically treated coconut fibres were used to reinforce Homopolymer Polypropylene in order to ascertain the effect of the treatments on the mechanical and water absorption properties of the composites produced. Coconut fibre was first extracted from its husk by soaking it in water and was dried before it was cut into 10 mm lengths. It was then chemically treated in alkali solution of sodium hydroxide (NaOH and potassium hydroxide (KOH in a shaker water bath. The treated coconut fibres were used as reinforcements in polypropylene matrix to produce composites of varied fibre weight contents; 2, 4, 6, 8 and 10 wt.%. Tensile and flexural properties were investigated using universal testing machine while water absorption test was carried out on the samples for 7 days. It was observed from the results that, NaOH treated samples gave the best tensile properties while KOH treated samples gave the best flexural and water repellent properties.

  13. Influence of the Organic Fertilizer Conditon the Content of Heavy Metals and Soil Chemical Properties

    Directory of Open Access Journals (Sweden)

    Ján Hecl

    2012-09-01

    Full Text Available Effect of amendment Condit on the mobility and uptake of Cd, Pb and Ni by crops, such as peas, spring barley, carrot and red beet, and selected chemical soil properties was tested in a field trial in years 2006–2008. Experimental field was situated close by sources of pollution, chemical factory Chemko Strážske and waste dump. The soil at experimental area was highly contaminated mainly by Cd. Heavy metals content was tested in the following parts of the crops: pea seed, spring barley green mater, carrot root and red beet root. Heavy metals content in soil and plant samples was detected in 2M HNO3 solution by the AAS method. It was found that Condit reduced Cd content in the soil under each cultivated crop. The most considerable Cd reducing (77.2% was at treatment with pea. The reduction of Pb and Ni content in the soil after Condit application was markedly lower as in the case of Cd, in comparison with control treatment. Positive effect of tested amendment Condit on reduction of Cd uptake was found by all crops under test. The best effect of Condit was found in carrot. Content of Cd in the carrot root was lower for about 55% compared with control treatment without amendment. Soil organic carbon content was significantly higher at treatment with Condit in comparison with control treatment. Measured content of soil organic carbon was higher by 1.16 g kg-1. The changes of soil carbon were insignificant at control treatment. Tested amendment Condit had significant impact on uptake of all measured heavy metals by plants. The result suggests that most significant impact had Condit on uptake of Cd. The measured amounts were the lowest of evaluated heavy metals.

  14. Influence of the Organic Fertilizer Conditon the Content of Heavy Metals and Soil Chemical Properties

    Directory of Open Access Journals (Sweden)

    Jan Hecl

    2014-02-01

    Full Text Available Effect of amendment Condit on the mobility and uptake of Cd, Pb and Ni by crops, such as peas, spring barley, carrot and red beet, and selected chemical soil properties was tested in a field trial in years 2006–2008. Experimental field was situated close by sources of pollution, chemical factory Chemko Strážske and waste dump. The soil at experimental area was highly contaminated mainly by Cd. Heavy metals content was tested in the following parts of the crops: pea seed, spring barley green mater, carrot root and red beet root. Heavy metals content in soil and plant samples was detected in 2M HNO3 solution by the AAS method. It was found that Condit reduced Cd content in the soil under each cultivated crop. The most considerable Cd reducing (77.2% was at treatment with pea. The reduction of Pb and Ni content in the soil after Condit application was markedly lower as in the case of Cd, in comparison with control treatment. Positive effect of tested amendment Condit on reduction of Cd uptake was found by all crops under test. The best effect of Condit was found in carrot. Content of Cd in the carrot root was lower for about 55% compared with control treatment without amendment. Soil organic carbon content was significantly higher at treatment with Condit in comparison with control treatment. Measured content of soil organic carbon was higher by 1.16 g kg-1. The changes of soil carbon were insignificant at control treatment. Tested amendment Condit had significant impact on uptake of all measured heavy metals by plants. The result suggests that most significant impact had Condit on uptake of Cd. The measured amounts were the lowest of evaluated heavy metals.

  15. Physical-chemical determinant properties of biological communities in continental semi-arid waters.

    Science.gov (United States)

    da Rocha, Francisco Cleiton; de Andrade, Eunice Maia; Lopes, Fernando Bezerra; de Paula Filho, Francisco José; Filho, José Hamilton Costa; da Silva, Merivalda Doroteu

    2016-08-01

    Throughout human history, water has undergone changes in quality. This problem is more serious in dry areas, where there is a natural water deficit due to climatic factors. The aims of this study, therefore, were (i) to verify correlations between physical attributes, chemical attributes and biological metrics and (ii) from the biological attributes, to verify the similarity between different points of a body of water in a tropical semi-arid region. Samples were collected every 2 months, from July 2009 to July 2011, at seven points. Four physical attributes, five chemical attributes and four biological metrics were investigated. To identify the correlations between the physicochemical properties and the biological metrics, hierarchical cluster analysis (HCA) and canonical correlation analysis (CCA) were applied. Nine classes of phytoplankton were identified, with the predominance of species of cyanobacteria, and ten families of macroinvertebrates. The use of HCA resulted in the formation of three similar groups, showing that it was possible to reduce the number of sampling points when monitoring water quality with a consequent reduction in cost. Group I was formed from the waters at the high end of the reservoir (points P1, P2 and P3), group II by the waters from the middle third (points P4 and P5), and group III by the waters from the lower part of the reservoir (points P6 and P7). Richness of the phytoplanktons Cyanophyceae, Chorophyceae and Bacillariophyceae was the attribute which determined dissimilarity in water quality. Using CCA, it was possible to identify the spatial variability of the physicochemical attributes (TSS, TKN, nitrate and total phosphorus) that most influence the metrics of the macroinvertebrates and phytoplankton present in the water. Low macroinvertebrate diversity, with a predominance of indicator families for deterioration in water quality, and the composition of phytoplankton showing a predominance of cyanobacteria, suggests greater

  16. Visualization of physico-chemical properties and microbial distribution in soil and root microenvironments

    Science.gov (United States)

    Eickhorst, Thilo; Schmidt, Hannes

    2016-04-01

    Plant root development is influenced by soil properties and environmental factors. In turn plant roots can also change the physico-chemical conditions in soil resulting in gradients between roots and the root-free bulk soil. By releasing a variety of substances roots facilitate microbial activities in their direct vicinity, the rhizosphere. The related microorganisms are relevant for various ecosystem functions in the root-soil interface such as nutrient cycling. It is therefore important to study the impact and dynamics of microorganisms associated to different compartments in root-soil interfaces on a biologically meaningful micro-scale. The analysis of microorganisms in their habitats requires microscopic observations of the respective microenvironment. This can be obtained by preserving the complex soil structure including the root system by resin impregnation resulting in high quality thin sections. The observation of such sections via fluorescence microscopy, SEM-EDS, and Nano-SIMS will be highlighted in this presentation. In addition, we will discuss the combination of this methodological approach with other imaging techniques such as planar optodes or non-invasive 3D X-ray CT to reveal the entire spatial structure and arrangement of soil particles and roots. When combining the preservation of soil structure via resin impregnation with 16S rRNA targeted fluorescence in situ hybridization (FISH) single microbial cells can be visualized, localized, and quantified in the undisturbed soil matrix including the root-soil interfaces. The simultaneous use of multiple oligonucleotide probes thereby provides information on the spatial distribution of microorganisms belonging to different phylogenetic groups. Results will be shown for paddy soils, where management induced physico-chemical dynamics (flooding and drying) as well as resulting microbial dynamics were visualized via correlative microscopy in resin impregnated samples.

  17. Chemical soil properties in the river basin of Vacacaí-Mirim

    Directory of Open Access Journals (Sweden)

    Pedro Daniel da Cunha Kemerich

    2013-09-01

    Full Text Available The levels of metals in soils have increased gradually with the modernization of agriculture which has occurred in recent years. The human action performed by man in nature is the main cause of this phenomenon. On this basis, the present study’s aim is to evaluate changes in soil chemical properties due to different uses and occupations in the river basin of Vacacaí-Mirim. The technique used for analysis was EDXRF, where the values were spacialized with the aid of the software Surfer 10. Values for Barium ranged from the detection limit (DL to 7,608.27 mg/kg -1 with an average of 1,286.71± 2,295.18 mg/kg-1, the concentration of Phosphorus ranged from DL to 2,327.02 mg/kg -1 with an average of 676.45±700.05 mg/kg-1, Manganese anged from DL to 5,533.51 mg/kg -1 with an average of 1,057.34 ±1,380.81 mg/kg-1, the values for Silicon ranged 229,114.70 to 832,568.70 mg/kg-1 with a mean of 696,134.25±144,950.56 mg/kg -1, Zinc concentration ranged from DL to 429.98 mg/kg-1 with an average of 145.725±123.78 mg/kg-1. Based on these results, it is possible to identify that the concentrations of the metals studied and the land use are closely linked, since concentrations are higher in areas that have agricultural uses, which require larger amounts of chemicals. Thus, it can be observed that the soils under the uses of rice, soybeans and pasture had greater influence on the concentration of the element barium, phosphorus, however, had most influence by the land use in pasture and soybeans.

  18. The chemical and catalytic properties of nanocrystalline metal oxides prepared through modified sol-gel synthesis

    Science.gov (United States)

    Carnes, Corrie Leigh

    The goal of this research was to synthesize, characterize and study the chemical properties of nanocrystalline metal oxides. Nanocrystalline (NC) ZnO, CuO, NiO, Al2O3, and the binary Al2O 3/MgO and ZnO/CuO were prepared through modified sol gel methods. These NC metal oxides were studied in comparison to the commercial (CM) metal oxides. The samples were characterized by XRD, TGA, FTIR, BET, and TEM. The NC samples were all accompanied by a significant increase in surface area and decrease in crystallite size. Several chemical reactions were studied to compare the NC samples to the CM samples. One of the reactions involved a high temperature reaction between carbon tetrachloride and the oxide to form carbon dioxide and the corresponding metal chloride. A similar high temperature reaction was conducted between the metal oxide and hydrogen sulfide to form water and the corresponding metal sulfide. A room temperature gas phase adsorption was studied where SO2 was adsorbed onto the oxide. A liquid phase adsorption conducted at room temperature was the destructive adsorption of paraoxon (a toxic insecticide). In all reactions the NC samples exhibited greater activity, destroying or adsorbing a larger amount of the toxins compared to the CM samples. To better study surface area effects catalytic reactions were also studied. The catalysis of methanol was studied over the nanocrystalline ZnO, CuO, NiO, and ZnO/CuO samples in comparison to their commercial counterparts. In most cases the NC samples proved to be more active catalysts, having higher percent conversions and turnover numbers. A second catalytic reaction was also studied, this reaction was investigated to look at the support effects. The catalysis of cyclopropane to propane was studied over Pt and Co catalysts. These catalysts were supported onto NC and CM alumina by impregnation. By observing differences in the catalytic behavior, support effects have become apparent.

  19. Physical-chemical determinant properties of biological communities in continental semi-arid waters.

    Science.gov (United States)

    da Rocha, Francisco Cleiton; de Andrade, Eunice Maia; Lopes, Fernando Bezerra; de Paula Filho, Francisco José; Filho, José Hamilton Costa; da Silva, Merivalda Doroteu

    2016-08-01

    Throughout human history, water has undergone changes in quality. This problem is more serious in dry areas, where there is a natural water deficit due to climatic factors. The aims of this study, therefore, were (i) to verify correlations between physical attributes, chemical attributes and biological metrics and (ii) from the biological attributes, to verify the similarity between different points of a body of water in a tropical semi-arid region. Samples were collected every 2 months, from July 2009 to July 2011, at seven points. Four physical attributes, five chemical attributes and four biological metrics were investigated. To identify the correlations between the physicochemical properties and the biological metrics, hierarchical cluster analysis (HCA) and canonical correlation analysis (CCA) were applied. Nine classes of phytoplankton were identified, with the predominance of species of cyanobacteria, and ten families of macroinvertebrates. The use of HCA resulted in the formation of three similar groups, showing that it was possible to reduce the number of sampling points when monitoring water quality with a consequent reduction in cost. Group I was formed from the waters at the high end of the reservoir (points P1, P2 and P3), group II by the waters from the middle third (points P4 and P5), and group III by the waters from the lower part of the reservoir (points P6 and P7). Richness of the phytoplanktons Cyanophyceae, Chorophyceae and Bacillariophyceae was the attribute which determined dissimilarity in water quality. Using CCA, it was possible to identify the spatial variability of the physicochemical attributes (TSS, TKN, nitrate and total phosphorus) that most influence the metrics of the macroinvertebrates and phytoplankton present in the water. Low macroinvertebrate diversity, with a predominance of indicator families for deterioration in water quality, and the composition of phytoplankton showing a predominance of cyanobacteria, suggests greater

  20. Characterization of Anticancer, Antimicrobial, Antioxidant Properties and Chemical Compositions of Peperomia Pellucida Leaf Extract

    Directory of Open Access Journals (Sweden)

    Desy Fitrya Syamsumir

    2011-10-01

    Full Text Available Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium assay against human breast adenocarcinoma (MCF-7 cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then characterized using α, α-diphenyl-β-picrylhydrazyl (DPPH radical scavenging method and the chemical compositions were screened and identified using gas chromatography-mass spectrometry (GC-MS. The results of present study indicated that P. pellucida leaf extract possessed anticancer activities with half maximal inhibitory concentration (IC50 of 10.4±0.06 µg/ml. The minimum inhibitory concentration (MIC values were ranged from 31.25 to 125 mg/l in which the plant extract was found to inhibit the growth of Edwardsiella tarda, Escherichia coli, Flavobacterium sp., Pseudomonas aeruginosa and Vibrio cholerae at 31.25 mg/l; Klebsiella sp., Aeromonas hydrophila and Vibrio alginolyticus at 62.5 mg/l; and it was able to control the growth of Salmonella sp. and Vibrio parahaemolyticus at 125 mg/l. At the concentration of 0.625 ppt, the plant extract was found to inhibit 30% of DPPH, free radical. Phytol (37.88% was the major compound in the plant extract followed by 2-Naphthalenol, decahydro- (26.20%, Hexadecanoic acid, methyl ester (18.31% and 9,12-Octadecadienoic acid (Z,Z-, methyl ester (17.61%. Findings from this study indicated that methanol extract of P. pellucida leaf possessed vast potential as medicinal drug especially in breast cancer treatment.

  1. Effect of Grain Size on Selected Physico-Chemical Properties of Clay

    Directory of Open Access Journals (Sweden)

    Osumanu H. Ahmed

    2009-01-01

    Full Text Available Problem statement: Mixture of the right proportion of expanding and non-expanding clays to improve plasticity (moldability of clays used in the pot industry of Malaysia is yet to be well investigated. In addition, little is known about the choice of the right clay size to eliminate or reduce the content of undesirable compounds such as Fe2O3, Al2O3 to improve the strength of pots and roofing tiles in the country. The objective of this study was to investigate how selected physico-chemical properties of pottery clay relate to grain size of Nyalau series ((Typic Paleudults. Approach: Soil samples were refined into 25, 20 and 63 µm using size grading method. The mineralogical composition of the samples was determined using X-Ray Diffraction (XRD. The chemical composition of the samples was also determined using standard procedures. Firing was done at 800°C in a muffle furnace and the cracks of the samples recorded. Results: The clay particles with sizes 20 and 25 µm were higher in LOI and total C than that those of 63 µm regardless of grain size, the clay investigated had quartz (SiO2, illite-montmorillonite, Anatase ((TiO2 and kaolinite. Grading affected the concentrations of Fe, Al and Si as clays with particle sizes 20 and 25 µm had higher contents of the aforementioned elements compared with those of 63 µm. The clay with particles 63 µm had the best strength and this was so because the clay particles had the lowest amount of Fe, Al and Si. Conclusion: The strength of Malaysian pots could be improved upon proper grading of the clay particles.

  2. Influence of the Organic Fertilizer Conditon the Content of Heavy Metals and Soil Chemical Properties

    Directory of Open Access Journals (Sweden)

    Ján Hecl

    2012-10-01

    Full Text Available Effect of amendment Condit on the mobility and uptake of Cd, Pb and Ni by crops, such as peas, spring barley, carrot and red beet, and selected chemical soil properties was tested in a field trial in years 2006–2008. Experimental field was situated close by sources of pollution, chemical factory Chemko Strážske and waste dump. The soil at experimental area was highly contaminated mainly by Cd. Heavy metals content was tested in the following parts of the crops: pea seed, spring barley green mater, carrot root and red beet root. Heavy metals content in soil and plant samples was detected in 2M HNO3 solution by the AAS method. It was found that Condit reduced Cd content in the soil under each cultivated crop. The most considerable Cd reducing (77.2% was at treatment with pea. The reduction of Pb and Ni content in the soil after Condit application was markedly lower as in the case of Cd, in comparison with control treatment. Positive effect of tested amendment Condit on reduction of Cd uptake was found by all crops under test. The best effect of Condit was found in carrot. Content of Cd in the carrot root was lower for about 55% compared with control treatment without amendment. Soil organic carbon content was significantly higher at treatment with Condit in comparison with control treatment. Measured content of soil organic carbon was higher by 1.16 g kg-1. The changes of soil carbon were insignificant at control treatment. Tested amendment Condit had significant impact on uptake of all measured heavy metals by plants. The result suggests that most significant impact had Condit on uptake of Cd. The measured amounts were the lowest of evaluated heavy metals.

  3. A study on the medicinal mushroom Cordyceps militaris (L.) link: chemical characterization, antioxidant, antimicrobial and antiproliferative properties

    OpenAIRE

    Reis, Filipa S.; Stojković, Dejan; Glamočlija, Jasmina; Ćirić, Ana; Van Griensven, Leo J. L. D.; Soković, Marina; Isabel C. F. R. Ferreira

    2013-01-01

    The Cordyceps genus is well known for its medicinal properties. A number of bioactive constituents from Cordyceps species have been reported such as antibacterial, antifungal, immunopotentiating or antitumor agents [1]. The anti-inflammatory and anti-angiogenic properties of Cordyceps militaris (L.) Link have been reported as also the antioxidant activity of its cultured mycelium [2]. In this work, the chemical characterization of C. militaris was performed, includingbioactive ...

  4. Hygroscopic and Chemical Properties of Aerosols collected near a Copper Smelter: Implications for Public and Environmental Health

    OpenAIRE

    Sorooshian, Armin; Csavina, Janae; Shingler, Taylor; Dey, Stephen; Brechtel, Fred J.; Sáez, A. Eduardo; Betterton, Eric A.

    2012-01-01

    Particulate matter emissions near active copper smelters and mine tailings in the southwestern United States pose a potential threat to nearby environments owing to toxic species that can be inhaled and deposited in various regions of the body depending on the composition and size of the particles, which are linked by particle hygroscopic properties. This study reports the first simultaneous measurements of size-resolved chemical and hygroscopic properties of particles next to an active coppe...

  5. Computer modelling system of the chemical composition and treatment parameters influence on mechanical properties of structural steels

    OpenAIRE

    L.A. Dobrzański; R. Honysz

    2009-01-01

    Purpose: This paper presents Neuro-Lab. It is an authorship programme, which use algorithms of artificial intelligence for structural steels mechanical properties estimation.Design/methodology/approach: On the basis of chemical composition, parameters of heat and mechanical treatment and elements of geometrical shape and size this programme has the ability to calculate the mechanical properties of examined steel and introduce them as raw numeric data or in graphic as influence charts. Possibl...

  6. Effect of activation agents on the surface chemical properties and desulphurization performance of activated carbon

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Flue gas pollution is a serious environmental problem that needs to be solved for the sustainable development of China.The surface chemical properties of carbon have great influence on its desulphurization performance.A series of activated carbons (ACs) were prepared using HNO3,H2O2,NH3·H2O and steam as activation agents with the aim to introduce functional groups to carbon surface in the ACs preparation process.The ACs were physically and chemically characterized by iodine and SO2 adsorption,ultimate analysis,Boehm titration,and temperature-programmed reduction (TPR).Results showed that the iodine number and desulphurization capacity of NH3·H2O activated carbon (AC-NH3) increase with both activation time,and its desulphurization capacity also increases with the concentration of activation agent.However,HNO3 activated carbon (AC-HNO3) and H2O2 activated carbon (AC-H2O2) exhibit more complex behavior.Only their iodine numbers increase monotonously with activation time.Compared with steam activated AC (AC-H2O),the nitrogen content increases 0.232% in AC-NH3 and 0.077% in AC-HNO3.The amount of total basic site on AC-HNO3 is 0.19 mmol·g-1 higher than that on AC-H2O.H2O2 activation introduces an additional 0.08 mmol·g-1 carboxyl groups to AC surface than that introduced by steam activation.The desulphurization capacity of ACs in simulate flue gas desulphurization decreases as follows: AC-NH3 > AC-HNO3 > AC-H2O2 > AC-H2O.This sequence is in accord with the SO2 catalytic oxidation/oxidation ratio in the absence of oxygen and the oxidation property reflected by TPR.In the presence of oxygen,all adsorbed SO2 on ACs can be oxidized into SO3.The desulphurization capacity increases differently according to the activation agents;the desulphurization capacity of AC-NH3 and AC-HNO3 improves by 4.8 times,yet AC-H2O increases only by 2.62 as compared with the desulphurization of corresponding ACs in absence of oxygen.

  7. Physico-chemical properties of blends of palm olein with other vegetable oils

    Directory of Open Access Journals (Sweden)

    Mobin Siddique, Bazlul

    2010-12-01

    Full Text Available Palm oil (olein was blended with other edible oils for the enhancement of its market acceptability in terms of melting point depression and shelf life. The physico-chemical properties like viscosity, density, melting behavior, peroxide value (PV, saponification value (SV and iodine value (IV of four different binary blends with four vegetable oils were evaluated. Palm olein was found to be more stable against rancidity than the other oils. For the stability against oxidation and melting point depression the palm olein-canola (PO/CO blend was found to be better than the others. The Differential Scanning Calorimeter (DSC thermogram of the melting behavior of the blends traces some new polymorphs of the triglyceride. This study will help the oil producing industry to find out the most economically viable oil blends for cooking purposes, with maximum nutrition as well as desirable physico-chemical properties.

    Aceite de palma (oleína fue mezclada con otros aceites comestibles para aumentar su aceptabilidad en el mercado en términos de descenso del punto de fusión y mejora de su almacenamiento. Las propiedades físico-químicas tales como viscosidad, densidad, comportamiento en la fusión, valor de peróxidos (PV, valor de saponificación (SV e índice de yodo (IV de cuatro diferentes mezclas binarias con cuatro aceites vegetales fueron evaluadas. La oleína de palma fue más estable frente a la rancidez que otros aceites. En la estabilidad frente la oxidación y el descenso del punto de fusión, la mezcla de oleína de palma/canola (PO/CO fue mejor que las otras. Los termogramas del calorímetro diferencial de barrido (DSC referidos al comportamiento de fusión de las mezclas indican algunos nuevos polimorfismos de los triglicéridos. Este estudio podría ayudar a las empresas que elaboran aceites a encontrar los aceites económicamente más viables para cocinar, con buenas propiedades nutricionales, así como con unas propiedades f

  8. Microbial biomass and soil chemical properties under different land use systems in northeastern Pará

    Directory of Open Access Journals (Sweden)

    Elessandra Laura Nogueira Lopes

    2011-08-01

    Full Text Available The increase in agricultural production in the Brazilian Amazon region is mostly a result of the agricultural frontier expansion, into areas previously influenced by humans or of native vegetation. At the same time, burning is still used to clear areas in small-scale agricultural systems, leading to a loss of the soil productive capacity shortly after, forcing the opening of new areas. This study had the objective of evaluating the effect of soil preparation methods that involve plant residue shredding, left on the surface or incorporated to the soil, with or without chemical fertilization, on the soil chemical and biological properties. The experiment was conducted in 1995, in an experimental field of Yellow Latosol (Oxisol of the Embrapa Amazônia Oriental, northeastern Pará (Brazil. The experiment was arranged in randomized blocks, in a 2x6 factorial design, with two management systems and six treatments evaluated twice. The management systems consisted of rice (Oriza sativa, followed by cowpea (Vigna unguiculata with manioc (Manihot esculenta. In the first system the crops were planted in two consecutive cycles, followed by a three-year fallow period (natural regrowth; the second system consisted of one cultivation cycle and was left fallow for three years. The following treatments were applied to the secondary forest vegetation: slash and burn, fertilized with NPK (Q+NPK; slash and burn, without fertilizer NPK (Q-NPK; cutting and shredding, leaving the residues on the soil surface, fertilized with NPK (C+NPK; cutting and shredding, leaving residues on the soil surface, without fertilizer (C-NPK; cutting and shredding, with residue incorporation and fertilized with NPK (I+NPK; cutting and shredding, with residue incorporation and without NPK fertilizer (I-NPK. The soil was sampled in the rainier season (April 2006 and in the drier season (September 2006, in the 0-0.1 m layer. From each plot, 10 simple samples were collected in order to

  9. Electrochemically induced chemical sensor properties in graphite screen-printed electrodes: The case of a chemical sensor for uranium

    Energy Technology Data Exchange (ETDEWEB)

    Kostaki, Vasiliki T.; Florou, Ageliki B. [Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina, 451 10 Ioannina (Greece); Prodromidis, Mamas I., E-mail: mprodrom@cc.uoi.gr [Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina, 451 10 Ioannina (Greece)

    2011-10-01

    Highlights: > Electrochemical treatment endows analytical characteristics to SPEs. > A sensitive chemical sensor for uranium is described. > Performance is due to a synergy between electrochemical treatment and ink's solvents. > The amount of the solvent controls the achievable sensitivity. - Abstract: We report for the first time on the possibility to develop chemical sensors based on electrochemically treated, non-modified, graphite screen-printed electrodes (SPEs). The applied galvanostatic treatment (5 {mu}A for 6 min in 0.1 M H{sub 2}SO{sub 4}) is demonstrated to be effective for the development of chemical sensors for the determination of uranium in aqueous solutions. A detailed study of the effect of various parameters related to the fabrication of SPEs on the performance of the resulting sensors along with some diagnostic experiments on conventional graphite electrodes showed that the inducible analytical characteristics are due to a synergy between electrochemical treatment and ink's solvents. Indeed, the amount of the latter onto the printed working layer controls the achievable sensitivity. The preconcentration of the analyte was performed in an electroless mode in an aqueous solutions of U(VI), pH 4.6, and then, the accumulated species was reduced by means of a differential pulse voltammetry scan in 0.1 M H{sub 3}BO{sub 3}, pH 3. Under selected experimental conditions, a linear calibration curve over the range 5 x 10{sup -9} to 10{sup -7} M U(VI) was constructed. The 3{sigma} limit of detection at a preconcentration time of 30 min, and the relative standard deviation of the method were 4.5 x 10{sup -9} M U(VI) and >12% (n = 5, 5 x 10{sup -8} M U(VI)), respectively. The effect of potential interferences was also examined.

  10. Novel flame retardants: Estimating the physical-chemical properties and environmental fate of 94 halogenated and organophosphate PBDE replacements.

    Science.gov (United States)

    Zhang, Xianming; Sühring, Roxana; Serodio, Daniela; Bonnell, Mark; Sundin, Nils; Diamond, Miriam L

    2016-02-01

    In the wake of the listing by the Stockholm Convention of PBDEs, an increasing number of "novel" flame retardants (NFRs) are being used in products. The properties that make for desirable flame retardants can also lead to negative health effects, long environmental residence times and an affinity for organic matrices. While NFRs are currently in use, little information is available regarding their physical-chemical properties and environmental fate. In this study, 94 halogenated and organophosphate NFRs were evaluated for their persistence and long-range transport potential. Physical-chemical properties (namely liquid sub-cooled vapor pressure P(l) and solubility S(l), air-water (K(AW)), octanol-water (K(OW)), and octanol-air (K(OA)) partition coefficients) of the NFRs were predicted using three chemical property estimation tools: EPI Suite, SPARC and Absolv. Physical-chemical properties predicted using these tools were generally within 10(2)-10(3) for compounds with molecular weight chemical properties of compounds with >800 g/mol, and/or the presence of a heteroatom and/or a polar functional group could deviate by up to 10(12). According to the OECD P(OV) and LRTP Screening Tool, up to 40% of the NFRs have a persistence and/or long range transport potential of medium to high level of concern and up to 60% have persistence and or long range transport potential similar to the PBDEs they are replacing. Long range transport potential could be underestimated by the OECD model since the model under-predicts long range transport potential of some organophosphate compounds.

  11. Effect of layering sequence and chemical treatment on the mechanical properties of woven kenaf–aramid hybrid laminated composites

    International Nuclear Information System (INIS)

    Highlights: • The mechanical properties of woven kenaf/Kevlar hybrid composites were analysed. • The layering sequences affect the mechanical properties of hybrid composites. • Treated kenaf improves the mechanical properties of hybrid composites. - Abstract: This work aims to evaluate the effect of layering sequence and chemical treatment on mechanical properties of woven kenaf–Kevlar composites. Woven kenaf–aramid hybrid laminated composites fabricated through hand lay-up techniques by arranging woven kenaf and Kevlar fabrics in different layering sequences and by using treated kenaf mat. To evaluate the effect of chemical treatment on hybrid composites, the woven kenaf mat was treated with 6% sodium hydroxide (NaOH) diluted solution and compared mechanical properties with untreated kenaf hybrid composites. Results shows that the tensile properties of hybrid composites improved in 3-layer composites compared to 4-layer composites. Hybrid composite with Kevlar as outer layers display a better mechanical properties as compared to other hybrid composites. Tensile and flexural properties of treated hybrid composites are better than non-treated hybrid composites. The fractured surface of hybrid composites was investigated by scanning electron microscopy. This study is a part of exploration of potential application of the hybrid composite in high velocity impact application

  12. MODIFICATIONS OF CHEMICAL PROPERTIES OF MANURE IN THE PROCESS OF COMPOSTING

    Directory of Open Access Journals (Sweden)

    Marija Vukobratović

    2008-12-01

    Full Text Available Apart from the production of sufficient food quantities modern agricultural production should produce high- quality food, but also preserve the environment, primarily by preserving the soil as a natural, renewable, but also exhaustible resource. Preservation of soil directly emphasizes the concern about elementary properties of soil affecting its fertility. One of the measures is usage of organic manure. Manure is used most often in practice, and the processes of decomposition depending on the way of maintenance and manure removal of the cattle, and the conditions in which such stack is amassed and kept are not often desirably directed. During implementation of such manure, the expected positive effects appear to be the negative ones. Five different manure types have been composted in the experiment (cattle manure, horse, pig and poultry and the changes in the chemical properties have been monitored. During the process of composting significant changes have occured: pH level of initial compost materials has grown in all the composts (from 8 to over 9, except for the pig, which had the pH level below 7; EC had an average increase of 69%, and at the end of the research a very high EC was found out in the poultry (12.15 d•Sm-1 which is three times above the borderline values for substrates of container production and horse (8.75 d•Sm-1 which is almost twice the value. The entire process of composting is characterized by the decrease of the portion of organic carbon (on the average for 19.62%, while the dynamics of the portion of the total N is vice versa (average increase by 38%. C•N ratio in the composts decreased, as expected, below 20:1 and the highest decrease is with the cattle manure with the highest initial C•N ratio. The increase of NO3- and decrease of NH4+ were established.

  13. Chemical composition, functional and pasting properties of cassava starch and soy protein concentrate blends.

    Science.gov (United States)

    Chinma, Chiemela Enyinnaya; Ariahu, Charles Chukwuma; Abu, Joseph Oneh

    2013-12-01

    The chemical, functional and pasting properties of cassava starch and soy protein concentrate blends intended for biofilm processing were studied. Cassava starch and soy protein concentrates were prepared and mixed at different proportions (100: 0%; 90 : 10%; 80 : 20%; 70 : 30%; 60;40% and 50: 50%). Addition of varying levels of soy protein concentrates to cassava starch led to increases in moisture (from 7.10 to 9.17%), protein ( from 0.32 to 79.03%), ash (from 0.45 to 2.67%) and fat (from 0.17 to 0.98%) contents while crude fiber, carbohydrate and amylose contents decreased from ( 1.19 to 0.38%, 90.77 to 57.01% and 29.45 to 23.04%) respectively . Water absorption capacity and swelling power of cassava starch were improved as a result of soy protein concentrate addition while syneresis and solubility value of composite blends were lower than 100% cassava starch. In general, cassava-soy protein concentrate blends formed firmer gels than cassava starch alone. There were significant (p ≤ 0.05) increases in peak viscosity (from 160.12 to 268.32RVU), final viscosity (from 140.41 to 211.08RVU) and pasting temperature (from 71.00 to 72.32 °C ) of cassava starch due to addition of soy protein concentrate. These results suggest that the addition of soy protein concentrate to cassava starch affected the studied functional properties of cassava starch as evidenced by changes such as reduced syneresis, and solubility that are desirable when considering this biopolymer as an edible biofilm.

  14. Improvement of Physico-Chemical Properties of Recycled (Elastomers /Thermoplastics) Composites using Ionizing Radiation

    International Nuclear Information System (INIS)

    Recycling of ground tire rubber (GRT) not only solves the waste disposal problem and maintains environmental quality, but also saves the valuable and limited resource of fossil feedstock. The major problem in the recycling of rubber-like materials such as tires is the cross linked molecular structure of already vulcanized rubber, which not only prevents the softening and processing of waste rubber particles but also inhibits binding of the powder surface to the virgin material. Several reclamation methods have proposed to overcome these barriers, which have basically followed two main approaches: (1) the de vulcanization of cured rubber and (2) the surface modifications of waste particles. The de vulcanization of rubber causes the cleavage of crosslinks via chemical treatments, which make used rubber suitable to be reformulated and recurred into new articles. In consequence, this work is mainly aimed to prepare of de vulcanized rubber (DR) and evaluating mechanical, thermal, and morphological properties of the thermoplastic vulcanizations (TPVs) based on de vulcanized rubber blended with polypropylene, EPDM using peroxide under the effect of radiation dose and DR feed ratio. The efficiency of the compounding process has been examined by infrared spectroscopy (FTIR), X-ray diffraction and scanning electron microscopy (SEM). The mechanical and thermal behaviors of the blends composed of de vulcanized rubber (DR) , high crystalline polypropylene (PP) and EPDM in different proportions were studied. Evaluation of the mechanical and thermal properties of the developed blends, unirradiated and gamma irradiated, was carried out using tensile strength (Ts), elongation at break (Eb), hardness, TGA and DSC measurements.

  15. Characterization of soil chemical properties of strawberry fields using principal component analysis

    Directory of Open Access Journals (Sweden)

    Gláucia Oliveira Islabão

    2013-02-01

    Full Text Available One of the largest strawberry-producing municipalities of Rio Grande do Sul (RS is Turuçu, in the South of the State. The strawberry production system adopted by farmers is similar to that used in other regions in Brazil and in the world. The main difference is related to the soil management, which can change the soil chemical properties during the strawberry cycle. This study had the objective of assessing the spatial and temporal distribution of soil fertility parameters using principal component analysis (PCA. Soil sampling was based on topography, dividing the field in three thirds: upper, middle and lower. From each of these thirds, five soil samples were randomly collected in the 0-0.20 m layer, to form a composite sample for each third. Four samples were taken during the strawberry cycle and the following properties were determined: soil organic matter (OM, soil total nitrogen (N, available phosphorus (P and potassium (K, exchangeable calcium (Ca and magnesium (Mg, soil pH (pH, cation exchange capacity (CEC at pH 7.0, soil base (V% and soil aluminum saturation(m%. No spatial variation was observed for any of the studied soil fertility parameters in the strawberry fields and temporal variation was only detected for available K. Phosphorus and K contents were always high or very high from the beginning of the strawberry cycle, while pH values ranged from very low to very high. Principal component analysis allowed the clustering of all strawberry fields based on variables related to soil acidity and organic matter content.

  16. Structure and properties of braided sleeve preforms for chemical vapor infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Starr, T.L.; Fiadzo, O.G.; Hablutzel, N. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Technology

    1998-04-01

    In all composites the properties and structure of the reinforcement strongly influence the performance of the material. For some composites, however, the reinforcement also affects the fabrication process itself exerting an additional, second order influence on performance. This is the case for the chemical vapor infiltration (CVI) process for fabrication of ceramic matrix composites. In this process the matrix forms progressively as a solid deposit, first onto the fiber surfaces, then onto the previous layer of deposit, ultimately growing to fill the inter-fiber porosity. The transport of reactants to the surfaces and the evolved morphology of the matrix depend on the initial reinforcement structure. This structure can vary greatly and is controlled by such factors as fiber size and cross-section, the number of filaments and amount of twist per tow or yarn, and the weave or braid architecture. Often the choice of reinforcement is based on mechanical performance analysis or on the cost and availability of the material or on the temperature stability of the fiber. Given this choice, the composite densification process--CVI--must be optimized to attain a successful material. Ceramic fiber in the form of cylindrical braided sleeve is an attractive choice for fabrication of tube-form ceramic matrix composites. Multiple, concentric layers of sleeve can be placed over a tubular mandrel, compressed and fixed with a binder to form a freestanding tube preform. This fiber architecture is different than that created by layup of plain weave cloth--the material used in most previous CVI development. This report presents the results of the investigation of CVI densification of braided sleeve preforms and the evolution of their structure and transport properties during processing.

  17. Heat-deproteinated xenogeneic bone from slaughterhouse waste: Physico-chemical properties

    Indian Academy of Sciences (India)

    R Murugan; K Panduranga Rao; T S Sampath Kumar

    2003-08-01

    Xenogeneic bone procured from the slaughterhouse waste was deproteinated by heat treatment method intended for use as a bone substitute. The effect of heat treatment was investigated by thermal analysis and by physico-chemical methods such as X-ray powder diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The heat treatment temperatures for the bovine bone samples were predetermined by thermogravimetric (TG) analysis. The XRD results revealed that the process of heat treatment promoted the crystallinity of bone samples, particularly at 700 and 900°C. There was no secondary phase transformation detected for heat-deproteinated bone except the presence of the hydroxyapatite (HA) phase, which indicated its phase purity even at a higher temperature. The FTIR spectra of raw bone and bone heated at 300°C indicated the presence of organic macromolecules whereas these disappeared in the samples heated at 500, 700 and 900°C, which suggested the removal of antigenic organic matters around 500°C. The same results were also confirmed quantitatively by calculating the amount of collagen using hydroxyproline estimation. There was no significant change in the TG-thermogram of bone heated at 500, 700 and 900°C, which indicated their thermal stability. These findings implied that the heat treated bone at 500°C had properties similar to carbonated HA with low crystallinity, while 700 and 900°C samples had the same with higher crystallinity. As low temperature treatment does not alter morphological and structural properties, we propose that the 500°C heat treated xenogeneic bone may act as an excellent osteogenic bone substitute.

  18. Pure magnetic hard fct FePt nanoparticles: Chemical synthesis, structural and magnetic properties correlations

    Energy Technology Data Exchange (ETDEWEB)

    Suber, L., E-mail: lorenza.suber@ism.cnr.it [ISM-CNR, Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo Scalo, RM (Italy); Marchegiani, G. [ISM-CNR, Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo Scalo, RM (Italy); Olivetti, E.S.; Celegato, F.; Coïsson, M.; Tiberto, P. [INRIM, Electromagnetism Division, Strada delle Cacce 91, 10135 Torino (Italy); Allia, P. [DISAT Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Barrera, G. [Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 7, 10125 Torino (Italy); Pilloni, L. [UTTMAT-CHI, Via Anguillarese 10, 00123 S. Maria di Galeria, Roma (Italy); Barba, L. [IC-CNR, Area Science Park, SS 14 Km 163.5 Basovizza, 34149 Trieste (Italy); Padella, F. [UTTMAT-CHI, Via Anguillarese 10, 00123 S. Maria di Galeria, Roma (Italy); Cossari, P. [IGAG-CNR, Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo Scalo, RM (Italy); Chiolerio, A. [Istituto Italiano di Tecnologia, Center for Space Human Robotics, Corso Trento 21, 10129 Torino (Italy)

    2014-03-01

    FePt nanoparticles, containing a near-equal atomic percentage of Fe and Pt, with a face centered tetragonal structure (fct), are challenging for potential applications in high performance permanent magnets and high density data storage. In this study, we report on the chemical synthesis, carried out both solvothermally and hydrothermally in autoclave reacting iron (III) acetylacetonate and platinum (II) acetylacetonate with tri- or tetra-ethylene glycol, these employed as solvents, reducers and particle surface protecting agents as well. In both methods, a subsequent thermal treatment at high temperatures is necessary to transform the magnetic soft face centered cubic (fcc) phase to the hard fct one. Organic low-weight molecules, generally used to protect the nanoparticle surface and avoid particle aggregation, are decomposed by the thermal treatment resulting in particle aggregation and coalescence phenomena; on the contrary, in this case, a polymer matrix is formed as particle protecting agent and, by thermally treating the hydrothermally prepared nanoparticles up to 750 °C for 1 h, the pure magnetic hard fct phase is obtained while preserving the nanostructure. A detailed study is carried out on FePt nanoparticle structure (fcc and fct phases) and correlated to the magnetic properties of the system. - Highlights: • fct FePt nanoparticles for hard magnetic nanotechnology applications. • Influence of synthesis parameters on the precursor fcc FePt nanoparticle structure. • Easy hydrothermal method for preparing pure fct FePt nanoparticles. • Monitoring the role of temperature and time on the FePt fcc–fct phase transformation. • Correlation between FePt nanoparticle structural and magnetic properties.

  19. Chemical composition and physico-chemical properties of meat from capons as affected by breed and age

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, O.; Rodriguez, L.; Torres, A.; Cobos, A.

    2010-07-01

    The influence of the breed [Mos (Spanish indigenous breed), Sasso T-44 and X-44 (commercial strains)] and the age (5, 6, 7 and 8 months) of capons (castrated male cockerels) on some qualitative traits of breast and drumstick meat were studied. The chemical composition (dry matter, protein, lipid and ash contents), pH, water holding capacity, drip loss, cooking loss, colour and texture (compression test and shear force) were measured. In breast meat, the Mos capon showed lower water holding capacity, higher drip loss and was lighter than the other breeds. In drumstick meat, the Mos capon showed lower lipid content, lower water holding capacity and was lighter and less red than the other breeds. Chemical composition, pH, water holding capacity, drip loss, colour and texture of the meat were significantly influenced by the age of the capons. The meat of the youngest animals showed higher ash content, higher pH, lower water holding capacity, higher drip loss, higher lightness and lower shear test values, than that of the older ones. In conclusion, the capon meat quality is influenced by breed and age of the capons. (Author) 36 refs.

  20. Influence of the pore structure and surface chemical properties of activated carbon on the adsorption of mercury from aqueous solutions

    International Nuclear Information System (INIS)

    Highlights: • Activated carbons with different pore structure and surface chemical properties were prepared by modification process. • HgCl2 as a pollution target to evaluate the adsorption performance. • Influence of pore structure and surface chemical properties of activated carbon on adsorption of mercury was investigated. -- Abstract: Reactivation and chemical modification were used to obtain modified activated carbons with different pore structure and surface chemical properties. The samples were characterized by nitrogen absorption–desorption, Fourier transform infrared spectroscopy and the Bothem method. Using mercury chloride as the target pollutant, the Hg2+ adsorption ability of samples was investigated. The results show that the Hg2+ adsorption capacity of samples increased significantly with increases in micropores and acidic functional groups and that the adsorption process was exothermic. Different models and thermodynamic parameters were evaluated to establish the mechanisms. It was concluded that the adsorption occurred through a monolayer mechanism by a two-speed process involving both rapid adsorption and slow adsorption. The adsorption rate was determined by chemical reaction

  1. Effect of gamma irradiation on the microbial load, chemical and sensory properties of the goat meat

    International Nuclear Information System (INIS)

    The present study was undertaken to assess the quality characteristics and to evaluate the effects of gamma irradiation (0, 2, 4, and 6 kGy) of Jabaly Syrian goat meat on microbiological, chemical, and sensory characteristics during storage at 4 degree centigrade (1, 3, 4, and 5 weeks). Irradiation was effective in reducing the microbial load and increasing the shelf-life of goat meat. The radiation doses required to reduce the microorganisms by 90 percent (D10) in goat meat were 294 and 400 Gy for the Salmonella and E. coli, respectively. The main fatty acids identified from the goat meat were oleic, stearic, and palmitic acids. No significant differences were observed in moisture, crud protein, crud fat, ash, pH value, fatty acids, total acidity, volatile basic nitrogen, and sensory properties (texture, flavor, color, and taste) of the radiation processing and non-irradiated goat meat. Lipid peroxidation measured in term of thiobarbituric acid-reactive substances (TBARS) on irradiation and chilled storage increased. (Author)

  2. Magnetic microgels for drug targeting applications: Physical–chemical properties and cytotoxicity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Turcu, Rodica, E-mail: rodica.turcu@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293 Cluj-Napoca (Romania); Craciunescu, Izabell [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293 Cluj-Napoca (Romania); Garamus, Vasil M. [Helmholtz-Zentrum Geesthacht, Zentrum für Material- und Küstenforschung GmbH, 21502 Geesthacht (Germany); Janko, Christina; Lyer, Stefan; Tietze, Rainer; Alexiou, Christoph [ENT-Department, Else Kröner-Fresenius Stiftung-Professorship, Section for Experimental Oncology and Nanomedicine (SEON), University Hospital Erlangen (Germany); Vekas, Ladislau, E-mail: vekas@acad-tim.tm.edu.ro [Romanian Academy-Timisoara Branch, CFATR, Laboratory of Magnetic Fluids, Mihai Viteazul Street 24, 300223 Timisoara (Romania)

    2015-04-15

    Magnetoresponsive microgels with high saturation magnetization values have been obtained by a strategy based on the miniemulsion method using high colloidal stability organic carrier ferrofluid as primary material. Hydrophobic nanoparticles Fe{sub 3}O{sub 4}/oleic acid are densely packed into well-defined spherical nanoparticle clusters coated with polymers with sizes in the range 40–350 nm. Physical–chemical characteristics of magnetic microgels were investigated by TEM, SAXS, XPS and VSM measurements with the focus on the structure–properties relationship. The impact of magnetic microgels loaded with anticancer drug mitoxantrone (MTO) on the non-adherent human T cell leukemia line Jurkat was investigated in multiparameter flow cytometry. We showed that both MTO and microgel-loaded MTO penetrate into cells and both induce apoptosis and later secondary necrosis in a time- and dose dependent manner. In contrast, microgels without MTO are not cytotoxic in the corresponding concentrations. Our results show that MTO-loaded microgels are promising structures for application in magnetic drug targeting. - Highlights: • Densely packed spherical clusters of magnetic nanoparticles were obtained. • High magnetization microgels with superparamagnetic behavior are reported. • The facile and reproducible synthesis procedure applied is easy to be up-scaled. • The toxicity tests show that magnetic microgels are not cytotoxic. • We show that mitoxantrone loaded microgels induce death of Jurkat cells.

  3. Chemical abundances and properties of the ionized gas in NGC 1705

    CERN Document Server

    Annibali, F; Pasquali, A; Aloisi, A; Mignoli, M; Romano, D

    2015-01-01

    We obtained [O III] narrow-band imaging and multi-slit MXU spectroscopy of the blue compact dwarf (BCD) galaxy NGC 1705 with FORS2@VLT to derive chemical abundances of PNe and H II regions and, more in general, to characterize the properties of the ionized gas. The auroral [O III]\\lambda4363 line was detected in all but one of the eleven analyzed regions, allowing for a direct estimate of their electron temperature. The only object for which the [O III]\\lambda4363 line was not detected is a possible low-ionization PN, the only one detected in our data. For all the other regions, we derived the abundances of Nitrogen, Oxygen, Neon, Sulfur and Argon out to ~1 kpc from the galaxy center. We detect for the first time in NGC 1705 a negative radial gradient in the oxygen metallicity of -0.24 \\pm 0.08 dex kpc^{-1}. The element abundances are all consistent with values reported in the literature for other samples of dwarf irregular and blue compact dwarf galaxies. However, the average (central) oxygen abundance, 12 +...

  4. The critical role of didodecyldimethylammonium bromide on physico-chemical, technological and biological properties of NLC.

    Science.gov (United States)

    Carbone, C; Campisi, A; Manno, D; Serra, A; Spatuzza, M; Musumeci, T; Bonfanti, R; Puglisi, G

    2014-09-01

    Exploiting the experimental factorial design and the potentiality of Turbiscan AG Station, we developed and characterized unmodified and DDAB-coated NLC prepared by a low energy organic solvent free phase inversion temperature technique. A 22 full factorial experimental design was developed in order to study the effects of two independent variables (DDAB and ferulic acid) and their interaction on mean particle size and zeta potential values. The factorial planning was validated by ANOVA analysis; the correspondence between the predicted values of size and zeta and those measured experimentally confirmed the validity of the design and the equation applied for its resolution. The DDAB-coated NLC were significantly affected in their physico-chemical properties by the presence of DDAB, as showed by the results of the experimental design. The coated NLC showed higher physical stability with no particles aggregation compared to the unmodified NLC, as demonstrated by Turbiscan(®) AGS measurements. X-ray diffraction, Raman spectroscopy and Cryo-TEM images allowed us to assert that DDAB plays a critical role in increasing the lipids structural order with a consequent enhancement of the NLC physical stability. Furthermore, the results of the in vitro biological studies allow the revisiting of the role of DDAB to the benefit of glioblastoma treatment, due to its efficacy in increasing the NLC uptake and reducing the viability of human glioblastoma cancer cells (U87MG). PMID:24929522

  5. Structure-property evaluation of thermally and chemically gelling injectable hydrogels for tissue engineering.

    Science.gov (United States)

    Ekenseair, Adam K; Boere, Kristel W M; Tzouanas, Stephanie N; Vo, Tiffany N; Kasper, F Kurtis; Mikos, Antonios G

    2012-09-10

    The impact of synthesis and solution formulation parameters on the swelling and mechanical properties of a novel class of thermally and chemically gelling hydrogels combining poly(N-isopropylacrylamide)-based thermogelling macromers containing pendant epoxy rings with polyamidoamine-based hydrophilic and degradable diamine cross-linking macromers was evaluated. Through variation of network hydrophilicity and capacity for chain rearrangement, the often problematic tendency of thermogelling hydrogels to undergo significant syneresis was addressed. The demonstrated ability to tune postformation dimensional stability easily at both the synthesis and formulation stages represents a significant novel contribution toward efforts to utilize poly(N-isopropylacrylamide)-based polymers as injectable biomaterials. Furthermore, the cytocompatibility of the hydrogel system under relevant conditions was established while demonstrating time- and dose-dependent cytotoxicity at high solution osmolality. Such injectable in situ forming degradable hydrogels with tunable water content are promising candidates for many tissue-engineering applications, particularly for cell delivery to promote rapid tissue regeneration in non-load-bearing defects.

  6. Magnetic microgels for drug targeting applications: Physical-chemical properties and cytotoxicity evaluation

    Science.gov (United States)

    Turcu, Rodica; Craciunescu, Izabell; Garamus, Vasil M.; Janko, Christina; Lyer, Stefan; Tietze, Rainer; Alexiou, Christoph; Vekas, Ladislau

    2015-04-01

    Magnetoresponsive microgels with high saturation magnetization values have been obtained by a strategy based on the miniemulsion method using high colloidal stability organic carrier ferrofluid as primary material. Hydrophobic nanoparticles Fe3O4/oleic acid are densely packed into well-defined spherical nanoparticle clusters coated with polymers with sizes in the range 40-350 nm. Physical-chemical characteristics of magnetic microgels were investigated by TEM, SAXS, XPS and VSM measurements with the focus on the structure-properties relationship. The impact of magnetic microgels loaded with anticancer drug mitoxantrone (MTO) on the non-adherent human T cell leukemia line Jurkat was investigated in multiparameter flow cytometry. We showed that both MTO and microgel-loaded MTO penetrate into cells and both induce apoptosis and later secondary necrosis in a time- and dose dependent manner. In contrast, microgels without MTO are not cytotoxic in the corresponding concentrations. Our results show that MTO-loaded microgels are promising structures for application in magnetic drug targeting.

  7. The imprint of satellite accretion on the chemical and dynamical properties of disc galaxies

    CERN Document Server

    Ruiz-Lara, T; Gibson, B K; Pérez, I; Florido, E; Minchev, I; Sánchez-Blázquez, P

    2015-01-01

    Aims: We study the effects of the cosmological assembly history on the chemical and dynamical properties of the discs of spiral galaxies as a function of radius. Methods: We make use of the simulated Milky-Way mass, fully-cosmological discs, from {\\tt RaDES} (Ramses Disc Environment Study). We analyse their assembly history by examining the proximity of satellites to the galactic disc, instead of their merger trees, to better gauge which satellites impact the disc. We present stellar age and metallicity profiles, Age-Metallicity Relation (AMR), Age-Velocity dispersion Relation (AVR), and Stellar Age Distribution (SAD) in several radial bins for the simulated galaxies. Results: Assembly histories can be divided into three different stages: i) a merger dominated phase, when a large number of mergers with mass ratios of $\\sim$1:1 take place (lasting $\\sim$3.2$\\pm$0.4 Gyr on average); ii) a quieter phase, when $\\sim$1:10 mergers take place (lasting $\\sim$4.4$\\pm$2.0 Gyr) - these two phases are able to kinematical...

  8. Discrimination of Chinese traditional soy sauces based on their physico-chemical properties

    Institute of Scientific and Technical Information of China (English)

    KOKOT; Serge

    2010-01-01

    This work aimed to classify the categories (produced by different processes) and brands (obtained from different geographical origins) of Chinese soy sauces.Nine variables of physico-chemical properties (density,pH,dry matter,ashes,electric conductivity,amino nitrogen,salt,viscosity and total acidity) of 53 soy sauce samples were measured.The measured data was submitted to such pattern recognition as cluster analysis (CA),principal component analysis (PCA),discrimination partial least squares (DPLS),linear discrimination analysis (LDA) and K-nearest neighbor (KNN) to evaluate the data patterns and the possibility of differentiating Chinese soy sauces between different categories and brands.Two clusters corresponding to the two categories were obtained,and each cluster was divided into three subsets corresponding to three brands by the CA method.The variables for LDA and KNN were selected by the Fisher F-ratio approach.The prediction ability of all classifiers was evaluated by cross-validation.For the three supervised discrimination analyses,LDA and KNN gave 100% predications according to the sample category and brand.

  9. Effects of barriers on chemical and biological properties of two dual resin cements.

    Science.gov (United States)

    Nocca, Giuseppina; Iori, Andrea; Rossini, Carlo; Martorana, Giuseppe E; Ciasca, Gabriele; Arcovito, Alessandro; Cordaro, Massimo; Lupi, Alessandro; Marigo, Luca

    2015-06-01

    The aim of this study was to investigate the degree of conversion, monomer release, and cytotoxicity of two dual-cure resin cements (Cement-One and SmartCem2), light-cured across two indirect restorative materials in an attempt to simulate in vitro the clinical conditions. The results obtained show that the degree of conversion was influenced by both barriers, but the effect of the composite material was greater than that of the ceramic one. The amount of monomers released from the polymerized materials in the absence of barriers was significantly lower than that released in the presence of either the ceramic or the composite barrier. However, a higher amount of monomers was released in the presence of the ceramic barrier. All materials, in all the experimental conditions employed, induced slight cytotoxicity (5-10%) on human pulp cells. Our examinations showed that the two resin cements had similar chemical and biological properties. The decreased degree of conversion of the dual-curing self-adhesive composite showed that the light-curing component of these materials has an important role in the polymerization process. In clinical practice, it is therefore important to pay attention to the thickness of the material used for the reconstruction.

  10. Preliminary studies on the chemical characterization and antioxidant properties of acidic polysaccharides from Sargassum fusiforme

    Institute of Scientific and Technical Information of China (English)

    Jing ZHOU; Nan HU; Ya-lin WU; Yuan-jiang PAN; Cui-rong SUN

    2008-01-01

    In order to investigate the antioxidant properties of the polysaccharides from the brown alga Sargassum fusiforme, the crude polysaccharides from S.fusiforme (SFPS) were extracted in hot water, and the lipid peroxidation inhibition assay exhibited that SFPS possessed a potential antioxidant activity. Hence, two purely polymeric fractions, SFPS-1 and SFPS-2 were isolated by the column of DEAE (2-diethylaminoethanol)-Sepharose Fast Flow, with their molecular weights of 51.4 and 30.3 kDa determined by high performance gel permeation chromatography (HPGPC). They were preliminarily characterized using chemical analysis in combination of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and found to contain large amounts of uronic acids and β-glycosidical linkages. The antioxidant activities of these two SFPS fractions were evaluated using superoxide and hydroxyl radical-scavenging assays. The results show that the antioxidant ability of SFPS-2 was higher than that of SFPS-1, probably correlating with the molecular weight and uronic acid content.

  11. Magnetic properties of Ni nanoparticles embedded in silica matrix (KIT-6) synthesized via novel chemical route

    International Nuclear Information System (INIS)

    Thermally stable Ni nanoparticles have been embedded in mesoporous silica matrix (KIT-6) via novel chemical reduction method by using superhydride as reducing agent. X-ray diffraction (XRD) study confirms that pure and embedded Ni nanoparticles crystallize in face centered cubic (fcc) structure. Crystallite sizes of pure Ni, 4 wt% and 8 wt% Ni in silica were estimated to be 6.0 nm, 10.4 nm and 10.5 nm, respectively. Morphology and dispersion of Ni in silica matrix were studied by scanning electron microscopy (SEM). Magnetic study shows enhancement of magnetic moments of Ni nanoparticles embedded in silica matrix compared with that of pure Ni. The result has been interpreted on the basis of size reduction and magnetic exchange effects. Saturation magnetization values for pure Ni, 4 wt% and 8 wt% Ni in silica were found to be 15.77 emu/g, 5.08 emu/g and 2.00 emu/g whereas coercivity values were 33.72 Oe, 92.47 Oe and 64.70 Oe, respectively. We anticipate that the observed magnetic properties may find application as soft magnetic materials

  12. Magnetic properties of Ni nanoparticles embedded in silica matrix (KIT-6) synthesized via novel chemical route

    Energy Technology Data Exchange (ETDEWEB)

    Dalavi, Shankar B.; Panda, Rabi N., E-mail: rnp@goa.bits-pilani.ac.in [Department of Chemistry, BITS-Pilani, K. K. Birla Goa Campus, Zuarinagar, Goa-403726 (India); Raja, M. Manivel [Defence Metallurgical Research Laboratory, Hyderabad-500058 (India)

    2015-06-24

    Thermally stable Ni nanoparticles have been embedded in mesoporous silica matrix (KIT-6) via novel chemical reduction method by using superhydride as reducing agent. X-ray diffraction (XRD) study confirms that pure and embedded Ni nanoparticles crystallize in face centered cubic (fcc) structure. Crystallite sizes of pure Ni, 4 wt% and 8 wt% Ni in silica were estimated to be 6.0 nm, 10.4 nm and 10.5 nm, respectively. Morphology and dispersion of Ni in silica matrix were studied by scanning electron microscopy (SEM). Magnetic study shows enhancement of magnetic moments of Ni nanoparticles embedded in silica matrix compared with that of pure Ni. The result has been interpreted on the basis of size reduction and magnetic exchange effects. Saturation magnetization values for pure Ni, 4 wt% and 8 wt% Ni in silica were found to be 15.77 emu/g, 5.08 emu/g and 2.00 emu/g whereas coercivity values were 33.72 Oe, 92.47 Oe and 64.70 Oe, respectively. We anticipate that the observed magnetic properties may find application as soft magnetic materials.

  13. Comparative study of microbiological, chemical and sensory properties of kefirs produced in Estonia, Latvia and Lithuania.

    Science.gov (United States)

    Anton, Dea; Raudsepp, Piret; Roasto, Mati; Meremäe, Kadrin; Kuusik, Sirje; Toomik, Peeter; Elias, Priit; Laikoja, Katrin; Kaart, Tanel; Lepiku, Martin; Püssa, Tõnu

    2016-02-01

    In the current study the microbiological, sensory and chemical properties of 24 kefirs (12 producers) from Estonian, Latvian and Lithuanian retail market were determined using gas chromatography (GC), high performance liquid chromatography (HPLC-MS/MS-Q-TOF and LC-ion trap MS/MS), spectrophotometry and other methods. Antihypertensive, angiotensin-converting enzyme (ACE) inhibiting, antioxidant and antibacterial peptides were found in the kefir samples. According to the results of principal component analysis of 200 most abundant compounds obtained with HPLC-MS/MS-Q-TOF analysis, Estonian kefirs differed from the rest. Kefirs of Latvian and Lithuanian origin showed similarities in several characteristics, probably related to the starter cultures and technological processes. The fatty acids composition of all Baltic kefirs was uniform. The antioxidant capacity of the kefirs varied slightly, whereas intermediate positive correlation (r = 0.32, P < 0.05) was found between antioxidativity and total bacterial count. The lipid oxidation level, estimated as the content of linoleic and oleic acid primary oxidation products, oxylipins, was very low in all studied kefirs. Only one third of analysed kefirs met the requirements of the minimum sum of viable microorganisms, indicated in the Codex Standard for Fermented Milks. PMID:26869114

  14. Structural, energetic and electrical properties of boron nitride nanotubes interacting with DMMP chemical agent

    International Nuclear Information System (INIS)

    Highlights: • ab initio DFT calculations were used for interaction of DMMP with BNNTs. • Full structural optimization was performed for several possible active sites. • Electronic structure of the energetically favorable complexes was analyzed. • The stability of the most stable complex was evaluated at ambient condition. • First-principles calculations showed that DMMP is strongly bound to the small diameter BNNTs. - Abstract: The adsorption of DMMP as an intoxicating chemical warfare agent onto the boron nitride nanotube has been investigated by using density functional theory calculations. Several active sites were considered for both interacting systems and full structural optimization was performed to accurately find the energetically favorable state. It is found that DMMP molecule prefers to be adsorbed strongly on the top site above the B atom of a (5, 0) BNNT with a binding energy of about −103.24 kJ mol−1 and an O–B binding distance of 1.641 Å. We have performed a comparative investigation of BNNTs with different diameters and the results indicate that the DMMP adsorption ability for the side wall of the tubes significantly decreases for higher diameters BNNTs. Furthermore, the adsorption properties of DMMP molecule onto the BNNT have been investigated using the ab initio MD simulation at room temperature. Our result showed that BNNTs facilitates the DMMP detection at ambient conditions for practical applications

  15. Physico-Chemical Characteristics and Rheolgical Properties of Different Wheat Varieties Grown in Sindh

    Directory of Open Access Journals (Sweden)

    Mahvish Jabeen Channa

    2015-12-01

    Full Text Available This study was designed to investigate the physico-chemical and rheological properties of 17 wheat varieties (TJ-83, Jouhar, TD-1, Anmool, Mehran, Indus-66, Sindh B-1, Abadgar, Bhittai, Imdad, Mexi-Pak, Soughat, Blue Silver, Moomal, Marvi, Kiran, and Pak-70 commercially grown on experimental field of Agriculture Research Institute, Tandojam. The results revealed that moisture % were in range of 11 to 12 among all varieties, high protein content of about 15.2% was found in Mehran and Blue silver varieties, starch was found high in Maxi-pak (70.6%, high hardness values in Imdad (70.1% and Jouhar (70.2%. However, zeleny content was found high in Marvi, Abadgaar and Mehran i.e. 71%. Amylographic results showed that among all varieties the Bhittai variety required maximum temperature up to 65.7 oC for the beginning of gelatinization as compared to other varieties. The highest gelatinization temperature was noted up to 96.7 oC in Moomal whereas others had temperature from 82.7 to 89.0 oC. Highest gelatinization maxima (1782AU acquired by T.J-83 variety. The results of Farinograph showed that highest water absorption was noted in Anmool variety. The highest dough development time and dough stability were found highest in Kiran and Indus-66, respectively. T.D-1 and Jouhar varieties had highest break down time as well as highest Farinograph quality.

  16. Propeller-Shaped ZnO Nanostructures Obtained by Chemical Vapor Deposition: Photoluminescence and Photocatalytic Properties

    Directory of Open Access Journals (Sweden)

    S. L. Wang

    2012-01-01

    Full Text Available Propeller-shaped and flower-shaped ZnO nanostructures on Si substrates were prepared by a one-step chemical vapor deposition technique. The propeller-shaped ZnO nanostructure consists of a set of axial nanorod (50 nm in tip, 80 nm in root and 1 μm in length, surrounded by radial-oriented nanoribbons (20–30 nm in thickness and 1.5 μm in length. The morphology of flower-shaped ZnO nanostructure is similar to that of propeller-shaped ZnO, except the shape of leaves. These nanorods leaves (30 nm in diameter and 1–1.5 μm in length are aligned in a radial way and pointed toward a common center. The flower-shaped ZnO nanostructures show sharper and stronger UV emission at 378 nm than the propeller-shaped ZnO, indicating a better crystal quality and fewer structural defects in flower-shaped ZnO. In comparison with flower-shaped ZnO nanostructures, the propeller-shaped ZnO nanostructures exhibited a higher photocatalytic property for the photocatalytic degradation of Rhodamine B under UV-light illumination.

  17. Potassium fertilization for pineapple: effects on soil chemical properties and plant nutrition

    Directory of Open Access Journals (Sweden)

    Luiz Antonio Junqueira Teixeira

    2011-06-01

    Full Text Available A field experiment was carried out on an Ultisol located at the city of Agudos (22º30'S; 49º03'W, in the state of São Paulo, Brazil, in order to determine the effects of rates and sources of potassium fertilizer on nutritional status of 'Smooth Cayenne' pineapple and on some soil chemical properties. The experiment was a complete factorial design with four rates (0, 175, 350, and 700 kg ha-1 of K2O and three combinations of K sources (100% KCl, 100% K2SO4 and 40% K2SO4 + 60% KCl. Soil samples were taken from the depths 0-20 cm, 20-40 cm and 40-60 cm at planting and 14 months after. Nutritional status of pineapple plants was assessed by means of tissue analysis. Soil K availability increased with application of K fertilizer, regardless of K sources. Soil chlorine and Cl concentration in pineapple leaves increased with application of KCl or K2SO4+KCl. Plant uptake of potassium was shaped by soil K availability and by the application rates of K fertilizer, independently of K sources.

  18. Structural properties of zinc oxide deposited using atmospheric pressure combustion chemical vapour deposition

    International Nuclear Information System (INIS)

    In this study the deposition of thin zinc oxide (ZnO) films under atmospheric pressure conditions was investigated. The deposition technique applied was combustion chemical vapour deposition (CCVD), at which a propane–air mixture was combusted in a burner. Dissolved zinc nitrate was used as precursor, which was guided as aerosol droplets by the processing gas flow directly into the reaction zone. Fundamental investigations were performed to form undoped ZnO. The structural properties of the films were analysed in dependence of the substrate temperature during the coating process. The presence of crystalline ZnO structures was proved and differences in film growth and crystallite sizes are revealed. Additionally, the particles generated by the CCVD-flame are characterised. The thin films showed a slight excess of Zn and several states of binding energy could be observed by fitting the core level spectra. Scanning and transmission electron microscopy also indicated ordered structures and additionally different orientations of crystallites were observed. - Highlights: • Columnar growth structures of ZnO by CCVD were observed. • The presence of polycrystalline ZnO with (002) as main orientation was confirmed. • Initial particles significantly differ from crystallite sizes of the resulting films. • The films show an excess of Zn with a Zn-to-O ratio of around 1.7

  19. Chemical, Sensorial and Rheological Properties of a New Organic Rice Bran Beverage

    Institute of Scientific and Technical Information of China (English)

    Gerson Luis FACCIN; Leila do Nascimento VIEIRA; Letícia Adélia MIOTTo; Pedro Luiz Manique BARRETO; Edna Regina AMANTE

    2009-01-01

    Rice bran is a solid residue from rice polishing that is used in animal nutrition and rice oil production. Cultivation conditions with agro-toxics, lipids instability, and tendency for mycotoxin contamination restrict its application in human nutrition. Therefore, organic agriculture is an alternative to use the properties of rice bran. Rice bran beverage is a new cereal product from organic rice. This work presents the preliminary results of the chemical and rheological studies of a bath pasteurized rice bran beverage. Compared with integral defatted milk, soy extracts, and brown rice low-fat milk, the rice bran beverage studied in this work presents itself as an important source of minerals and unsaturated lipids. All essential amino acids were found in this product. Glutamic and aspartic acids were predominant. Bath pasteurization at boiling water temperature for 15 and 30 min was adequate for microbiological safety. Refrigeration storage for 20 days, evaluated by pH and acidity variations, was ideal for assessment of the beverage conservation time. The beverage viscosity was of the Newtonian standard behavior, and its viscosity during storage was not a good parameter to evaluate shelf life. Sensory preference tests showed positive perspectives for this new beverage.

  20. Effects of Irrigation Practices on Some Soil Chemical Properties on OMI Irrigation Scheme

    Directory of Open Access Journals (Sweden)

    M.A. Adejumobi

    2014-10-01

    Full Text Available Irrigation practices have been observed to impact scheme soil properties and other parameters negatively. These could be as a result of irrigation water quality, method of application and nature of scheme soil. This study was therefore conducted to study the effects of irrigation practices on the soils of Omi irrigation scheme Kogi state, Nigeria after 13years of operation. Soil samples were taken at depths 0 – 20 cm (A1, 20 – 80 cm (A2 and 80 – 120 cm (A3 from two operating lands (OL; OL 5 and OL 18 of the study area. The samples were analysed for chemical parameters (pH, CEC, ESP, Mg2+, Ca2+, OM, and OC. The soil pH which was in the neutral range (pH=6.65 to 7.00 at inception of scheme, has become slightly acidic (pH=6.53 to 6.60. Cation exchange capacity (CEC levels have also increased from 10cmol+kg-1 to 35cmol+kg-1. While Organic matter (OM and Organic carbon (OC also have marked increase in their levels (baseline as 0.93 to 1.08; for year 2013 as 9.52 to 9.79. Generally, the analysis indicated a need for proper monitoring of the scheme soil to prevent further deterioration.

  1. Effect of phosphogypsum amendment on soil physico-chemical properties, microbial load and enzyme activities.

    Science.gov (United States)

    Nayak, Soumya; Mishra, C S K; Guru, B C; Rath, Monalisa

    2011-09-01

    Phosphogypsum (PG) is produced as a solid waste from phosphatic fertilizer plants. The waste slurry is disposed off in settling ponds or in heaps. This solid waste is now increasingly being used as a calcium supplement in agriculture. This study reports the effectof PG amendmenton soil physico chemical properties, bacterial and fungal count and activities of soil enzymes such as invertase, cellulase and amylase over an incubation period of 28 days. The highest mean percent carbon loss (55.98%) was recorded in 15% PG amended soil followed by (55.28%) in 10% PG amended soil and the minimum (1.68%) in control soil. The highest number of bacterial colonies (47.4 CFU g(-1) soil), fungal count (17.8 CFU g(-1) soil), highest amylase activity (38.4 microg g(-1) soil hr(-1)) and cellulase activity (38.37 microg g(-1) soil hr(-1)) were recorded in 10% amended soil. Statistically significant difference (p<0.05) has been recorded in the activities of amylase and cellulase over the period of incubation irrespective of amendments. Considering the bacterial and fungal growth and the activities of the three soil enzymes in the control and amended sets, it appears that 10% PG amendment is optimal for microbial growth and soil enzyme activities.

  2. Structural properties of zinc oxide deposited using atmospheric pressure combustion chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zunke, I., E-mail: iz@innovent-jena.de [Innovent e.V. Technology Development, Department of Surface Engineering, Prüssingstr. 27B, 07745 Jena (Germany); Wolf, S. [University of Jena, Institute for Solid State Physics, Helmholtzweg 3/5, 07745 Jena (Germany); Heft, A.; Schimanski, A.; Grünler, B. [Innovent e.V. Technology Development, Department of Surface Engineering, Prüssingstr. 27B, 07745 Jena (Germany); Ronning, C.; Seidel, P. [University of Jena, Institute for Solid State Physics, Helmholtzweg 3/5, 07745 Jena (Germany)

    2014-08-28

    In this study the deposition of thin zinc oxide (ZnO) films under atmospheric pressure conditions was investigated. The deposition technique applied was combustion chemical vapour deposition (CCVD), at which a propane–air mixture was combusted in a burner. Dissolved zinc nitrate was used as precursor, which was guided as aerosol droplets by the processing gas flow directly into the reaction zone. Fundamental investigations were performed to form undoped ZnO. The structural properties of the films were analysed in dependence of the substrate temperature during the coating process. The presence of crystalline ZnO structures was proved and differences in film growth and crystallite sizes are revealed. Additionally, the particles generated by the CCVD-flame are characterised. The thin films showed a slight excess of Zn and several states of binding energy could be observed by fitting the core level spectra. Scanning and transmission electron microscopy also indicated ordered structures and additionally different orientations of crystallites were observed. - Highlights: • Columnar growth structures of ZnO by CCVD were observed. • The presence of polycrystalline ZnO with (002) as main orientation was confirmed. • Initial particles significantly differ from crystallite sizes of the resulting films. • The films show an excess of Zn with a Zn-to-O ratio of around 1.7.

  3. Influence of silane content and filler distribution on chemical-mechanical properties of resin composites

    Directory of Open Access Journals (Sweden)

    Tathy Aparecida XAVIER

    2015-01-01

    Full Text Available This study investigated the influence of silane concentration and filler size distribution on the chemical-mechanical properties of experimental composites. Experimental composites with silane contents of 0%, 1% and 3% (in relation to filler mass and composites with mixtures of barium glass particles (median size = 0.4, 1 and 2 μm and nanometric silica were prepared for silane and filler analyses, respectively. The degree of conversion (DC was analyzed by FTIR. Biaxial flexural strength (BFS was tested after 24-h or 90-d storage in water, and fracture toughness, after 24 h. The data were subjected to ANOVA and Tukey’s test (p = 0.05. The DC was not significantly affected by the silane content or filler distribution. The 0% silane group had the lowest immediate BFS, and the 90-d storage time reduced the strength of the 0% and 3% groups. BFS was not affected by filler distribution, and aging decreased the BFS of all the groups. Silanization increased the fracture toughness of both the 1% and 3% groups, similarly. Significantly higher fracture toughness was observed for mixtures with 2 μm glass particles. Based on the results, 3% silane content boosted the initial strength, but was more prone to degradation after water storage. Variations in the filler distribution did not affect BFS, but fracture toughness was significantly improved by increasing the filler size.

  4. Predicting physical and chemical water properties from relationships with watershed soil characteristics.

    Science.gov (United States)

    Shirazi, M A; Boersma, L; Johnson, C B; Haggerty, P K

    2001-01-01

    The Surface Waters component of the Environmental Monitoring and Assessment Program (EMAPSW) was developed by the USEPA to evaluate the extent and condition of lakes and streams over national and regional scales. Realistically, chemical or physical water properties (WPs) such as acidity or turbidity can be field-sampled for only a small portion of all lakes and streams. However, soil characteristics (SCs) affect WPs and broad-scale soil survey data have become available in the State Soil Geographic Data Base (STATSGO). We developed models relating observed WPs to SCs to extrapolate the sampled WPs to a region, potentially reducing extensive monitoring needs. Our study region consisted of 13 northeastern and Mid-Atlantic states and contained 882 STATSGO soil map units. We used map units as the spatial component of WP analysis. The WPs were sampled in 721 randomly selected EMAPSW study sites. The watersheds of these sites represent 7.1% of the region's total area and spatially intersect 400 of its soil map units. Each intersected map unit was assigned the weighted average WPs from the corresponding watersheds. Conditional expectation models were used to extrapolate sampled WPs to 882 map units. The relative standard errors ranged from low for pH (0.8%), intermediate for total P (12.1%), and very high for chloride (54.8%). The high extrapolation errors indicate outlier conditions from natural, non-soil, or anthropogenic sources.

  5. Effect of different alkali treatments on the chemical composition, physical properties, and microstructure of pidan white.

    Science.gov (United States)

    Zhang, Xianwei; Jiang, Aimin; Chen, Mingtsao; Ockerman, Herbert W; Chen, Jiaojiao

    2015-04-01

    Changes in chemical composition, physical property and microstructure of pidan white treated with 4.5 % NaOH or 5.5 % KOH were monitored during pickling up to 4 weeks, and followed by aging for another 2 weeks. As the pickling and ageing times increased, moisture content of pidan white decreased and salt content increased for both (4.5 % NaOH and 5.5 % KOH) treatments (P alkalinity and pH of pidan white treated with 4.5 % NaOH increased as pickling proceeded, but decreased during ageing for both pickling treatments (P hardness, cohesiveness, gumminess and chewiness than those treated with 4.5 % NaOH. After ageing, higher springiness, elastic modulus (G') and viscous modulus (G") were generally found in pidan white treated with 5.5 % KOH (P < 0.05). As the pickling time increased, lower L*, b* values and higher a* value were observed in pidan white from both treatments (P < 0.05). As visualized by scanning electron microscope, the aggregation of egg proteins took place in pidan white gels, irrespective of pickling treatments used. Nevertheless, closer and more orderly protein aggregates with denser network were founded in pidan white treated with 5.5 % KOH.

  6. Evaluation of physico-chemical properties of Portland cements and MTA

    Directory of Open Access Journals (Sweden)

    Jorge Luis Gonçalves

    2010-09-01

    Full Text Available The purpose of this study was to evaluate the hydrogenionic potential and electrical conductivity of Portland cements and MTA, as well as the amount of arsenic and calcium released from these materials. In Teflon molds, samples of each material were agitated and added to plastic flasks containing distilled water for 3, 24, 72 and 168 h. The results were analyzed with a Kruskal-Wallis non-parametric test for global comparisons and a Dunn-Tukey test for pairwise comparisons. The results revealed no significant differences in the pH of the materials (p > 0.05. The electrical conductivity of the cements were not statistically different (p > 0.05. White non-structural cement and MTA BIO released the largest amount of calcium ions into solution (p 0.05. The results indicated that the physico-chemical properties of Portland cements and MTA were similar. Furthermore, all materials produced an alkaline environment and can be considered safe for clinical use because arsenic was not released. The electrical conductivity and the amount of calcium ions released into solution increased over time.

  7. A Study on the Chemical Properties of Blue Compact Dwarf Galaxies

    CERN Document Server

    Zhao, Yinghe; Gu, Qiusheng

    2012-01-01

    In this paper, we report our studies on the gaseous and chemical properties of a relatively large sample (53 members) of blue compact dwarf galaxies (BCDs). The results of correlations among the oxygen abundance, stellar mass, gas mass, baryonic mass, and gas fraction are present both for E- and I-type BCDs, which are classified according to Loose & Thuan (1985) and show elliptical and irregular outer haloes, respectively. These correlations of I-type BCDs show similar slopes to those of E-type ones. However, in general, E-type BCDs are more gas-poor and metal-rich than I-type ones at a given baryonic mass. Based on these results, we suggest that E-type BCDs, at least a part of them, and I-type ones might be likely at different evolutionary phases and/or having different progenitors. Our investigation of the correlation between oxygen abundance and gas fraction shows that BCDs appear to have not evolved as isolated systems, but to have experienced some gas flows and/or mergers.

  8. Another brick in understanding chemical and kinematical properties of BSSs: NGC 6752

    Energy Technology Data Exchange (ETDEWEB)

    Lovisi, L.; Mucciarelli, A.; Dalessandro, E.; Ferraro, F. R.; Lanzoni, B. [Dipartimento di Fisica and Astronomia, Università degli Studi di Bologna, viale Berti Pichat 6/2, I-40127 Bologna (Italy)

    2013-11-20

    We used high-resolution spectra acquired with the multifiber facility FLAMES at the Very Large Telescope of the European Southern Observatory to investigate the chemical and kinematical properties of a sample of 22 blue straggler stars (BSSs) and 26 red giant branch stars in the nearby globular cluster NGC 6752. We measured radial and rotational velocities and Fe, O, and C abundances. According to radial velocities, metallicity, and proper motions, we identified 18 BSSs as likely cluster members. We found that all the BSSs rotate slowly (less than 40 km s{sup –1}), similar to the findings in 47 Tucanae, NGC 6397, and M30. The Fe abundance analysis reveals the presence of three BSSs affected by radiative levitation (showing [Fe/H] significantly higher than that measured in 'normal' cluster stars), confirming that element transport mechanisms occur in the photosphere of BSSs hotter than ≅8000 K. Finally, BSS C and O abundances are consistent with those measured in dwarf stars. No C and O depletion ascribable to mass transfer processes has been found on the atmospheres of the studied BSSs (at odds with previous results for 47 Tucanae and M30), suggesting the collisional origin for BSSs in NGC 6752 or that the CO depletion is a transient phenomenon.

  9. Chemical bath deposition and electrochromic properties of NiO{sub x} films

    Energy Technology Data Exchange (ETDEWEB)

    Ristova, M.; Velevska, J. [Physics Department, Faculty of Science, P. O. Box 162, Skopje (Macedonia); Ristov, M. [Macedonian Academy of Sciences and Arts, Skopje (Macedonia)

    2002-02-01

    Nickel oxide (NiO{sub x}) thin films were prepared by the chemical deposition method (solution growth) on two kinds of substrates: (1) glass and (2) glass/SnO{sub 2}:F. Films were thermally treated at 200C for 10min in atmosphere. The texture, microstructure and composition were examined by optical microscopy, X-ray diffraction patterns (XRD) and X-ray photoelectron spectroscopy (XPS) analysis of the surface layer. The films exhibited anode electrochromism. The optical properties of the bleached and colored state were examined with transmittance spectroscopy in the visible region and reflectance FTIR spectroscopy. An electrochromic test device (ECTD), consisting of SnO{sub 2}/NiO{sub x}/NaOH-H{sub 2}O/SnO{sub 2}, was assembled and tested by cyclic voltammetry combined with a simultaneous recording of the change of transparency at {lambda}=670nm. The coloration efficiency was evaluated to be 24.3cm{sup 2}/C. The spontaneous ex-situ change of coloration with time of the colored and bleached NiO{sub x}/SnO{sub 2}/glass was also examined.

  10. Electrochromic properties of porous NiO thin films prepared by a chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xia, X.H.; Tu, J.P.; Zhang, J.; Wang, X.L. [Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Zhang, W.K.; Huang, H. [College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)

    2008-06-15

    Highly porous nickel oxide thin films were prepared on ITO glass by a simple chemical bath deposition (CBD) method in combination with a following heat-treatment process. XRD analysis revealed that the as-deposited precursor film contained {beta}-Ni(OH){sub 2} and {gamma}-NiOOH, and they changed to cubic polycrystalline NiO after annealing. The FTIR results showed presence of free hydroxyl ion and water in the NiO thin films. The electrochromic properties of NiO thin films were investigated in an aqueous alkaline electrolyte (1 M KOH) by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The NiO thin film annealed at 300 C exhibited a noticeable electrochromism and good memory effect. The coloration efficiency was calculated to be 42 cm{sup 2} C{sup -1} at 550 nm, with a variation of transmittance up to 82%. The porous NiO thin films also showed good reaction kinetics with fast switching speed, and the coloration and bleaching time were 8 and 10 s, respectively. (author)

  11. Soil chemical properties, organic reserves and root system of a degraded pasture associated introduction of legume

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Santos Fabrice

    2014-09-01

    Full Text Available The aim was to study the recovery of degraded pasture with the introduction of Stylosanthes macrocephala e capitata cv. Campo Grande on Brachiaria decumbens cv. Basilisk evaluating the levels N-total in roots, biomass, area, and length, diameter and root levels of macro and micronutrients in the soil. The experiment was conducted in the municipality of Andradina, São Paulo State, Brazil. The experimental design was a randomized block design in a split-plot (with and without phosphorus, with four replicates, forming the following treatments: control Brachiaria decumbens (CB, partial desiccation with 1.5 L ha-1 of glyphosate (DP, total desiccation with 3.0 L ha-1 of glyphosate (TD; tillage (T, soil scarification (S; harrowing rome (H and plowing + disking (PD. Treatments H and PD were sown by broadcasting and the other in the form of direct seeding. Recovery strategies of grazing signal grass showed significant differences between treatments only for the content of N-total, there were no differences in geometric characteristics of roots and root biomass. The contents of macro and micronutrients in the soil showed no significant differences between the strategies of recovery. Fertilization had a significant effect for P. The introduction of estilosantes Campo Grande accompanied by techniques such as drying and plowing + disking contributed to increases in the N-total levels in the root system. Forms of introduction of legumes did not change the soil chemical properties.

  12. Changes in chemical properties of distrophic Red Latosol as result of swine wastewater application

    Directory of Open Access Journals (Sweden)

    Juarez R. Cabral

    2014-02-01

    Full Text Available Swine wastewater (SW has characteristics that allow its disposal in the soil as a fertilizer. This is an alternative in order not to accumulate this material in the farm as well as it provides savings with mineral fertilizers. The aim of this study was to evaluate the effect of applying swine wastewater on the chemical properties of a distrophic Red Latosol for two seasons. The experiment was carried out under field conditions with treatments defined as T0 = 0 (control, T1 = 150, T2 = 300, T3 = 450, T4 = 600, T5 = 750 m3 ha-1 of SW applied during the crop cycle of elephant grass. SW application contributed to the increase of magnesium and phosphorus and the reduction of soil aluminum in the first season. As for the second season when compared to the first one, there were reductions in K, Ca, and P concentrations. Hence applications of SW did not contribute to the increase in concentration of elements in the soil.

  13. A STUDY ON THE CHEMICAL PROPERTIES OF BLUE COMPACT DWARF GALAXIES

    International Nuclear Information System (INIS)

    In this paper, we report our studies on the gaseous and chemical properties of a relatively large sample (53 members) of blue compact dwarf galaxies (BCDs). The results of correlations among the oxygen abundance, stellar mass, gas mass, baryonic mass, and gas fraction are present both for E- and I-type BCDs, which are classified according to Loose and Thuan and show elliptical and irregular outer haloes, respectively. These correlations of I-type BCDs show slopes similar to those of E-type ones. However, in general, E-type BCDs are more gas-poor and metal-rich than I-type ones at a given baryonic mass. Based on these results, we suggest that E-type BCDs, at least a part of them, and I-type ones might be likely at different evolutionary phases and/or having different progenitors. Our investigation of the correlation between oxygen abundance and gas fraction shows that BCDs appear to have not evolved as isolated systems, but to have experienced some gas flows and/or mergers.

  14. Structural, Optical and Electrical Properties of Nanocrystalline Cuprous Oxide Thin Film Deposited By Chemical Method

    Directory of Open Access Journals (Sweden)

    Prakash Bansilal Ahirrao

    2010-06-01

    Full Text Available Cuprous oxide (Cu2O is an interesting p-type semiconductor material used in solar cell applications.  The Modified Chemical Bath Deposition (M-CBD method is suitable for growing thin multilayer structure due to low deposition temperature. This method does not require any sophisticated instrument and substrate need not to be conductive. The nanocrystalline Cu2O thin films were deposited on glass substrates by M-CBD method. The deposited films were characterized by different characterization techniques to study structural, surface morphological, optical and electrical properties. The structural studies show that, the formation of Cu2O thin films with an average crystallite size of 14 nm. Optical studies show a direct band gap 2.48 eV. The room temperature electrical resistivity is of the order of 1.3 kW-cm and activation energy 0.33 eV. The films exhibit p-type electrical conductivity as seen by thermo-emf measurements.

  15. Aggregate Stability and Its Relationship with Some Chemical Properties of Red Soils in Subtropical China

    Institute of Scientific and Technical Information of China (English)

    LI Zhao-Xia; CAI Chong-Fa; SHI Zhi-Hua; WANG Tian-Wei

    2005-01-01

    The stability of aggregates in the surface soil is crucial to soil erosion and runoff generation. Thus, to understand the stability and the breakdown mechanisms of soil aggregates as well as the relationship between aggregate stability and selected soil chemical properties, such as different forms of Fe and Al oxides, organic matter, CEC and clay content, the aggregates of slightly and severely eroded red soils derived from Quaternary red clay in subtropical China were analyzed using the routine wet sieving and the Le Bissonnais methods. The results indicated that the aggregates of the severely eroded soils were more stable than those of the slightly eroded soils. Different aggregate breakdown mechanisms resulted in different particle size distribution. The slaking from entrapped air in aggregates severely destroyed the soil aggregates,especially in the slightly eroded soils. Meanwhile, mechanical breakdown and microcracking had little effect on the aggregates compared to slaking. The fragments resulting from slaking were mainly microaggregates that increased in size with increasing clay content. The main fragment size of the slightly eroded soils was 1.0-0.2 mm, while for the severely eroded soils it was 5.0-2.0 mm and 1.0-0.5 mm. Overall, more than 20% of the fragments were smaller than 0.2 mm.In addition, aggregate stability was positively and often significantly correlated with Fed, Ald, Feo and clay content, but significantly and negatively correlated to SOC.

  16. Physico-chemical properties, antioxidant activity and mineral contents of pineapple genotypes grown in china.

    Science.gov (United States)

    Lu, Xin-Hua; Sun, De-Quan; Wu, Qing-Song; Liu, Sheng-Hui; Sun, Guang-Ming

    2014-01-01

    The fruit physico-chemical properties, antioxidant activity and mineral contents of 26 pineapple [Ananas comosus (L.) Merr.] genotypes grown in China were measured. The results showed great quantitative differences in the composition of these pineapple genotypes. Sucrose was the dominant sugar in all 26 genotypes, while citric acid was the principal organic acid. Potassium, calcium and magnesium were the major mineral constituents. The ascorbic acid (AsA) content ranged from 5.08 to 33.57 mg/100 g fresh weight (FW), while the total phenolic (TP) content varied from 31.48 to 77.55 mg gallic acid equivalents (GAE)/100 g FW. The two parameters in the predominant cultivars Comte de Paris and Smooth Cayenne were relative low. However, MD-2 indicated the highest AsA and TP contents (33.57 mg/100 g and 77.55 mg GAE/100 g FM, respectively), and it also showed the strongest antioxidant capacity 22.85 and 17.30 μmol TE/g FW using DPPH and TEAC methods, respectively. The antioxidant capacity of pineapple was correlated with the contents of phenolics, flavonoids and AsA. The present study provided important information for the further application of those pineapple genotypes.

  17. The physico-chemical properties of some citrus seeds and seed oils.

    Science.gov (United States)

    Juhaimi, Fahad A L; Matthäus, Bertrand; Özcan, Mehmet Musa; Ghafoor, Kashif

    2016-03-01

    The chemical properties, mineral contents, fatty acid and tocopherol contents of seed and seed oils of some citrus genus provided from several locations in Turkey and Saudi Arabia were determined. While Ca contents of seeds were between 5018 mg/kg (Kütdiken lemon) and 7619 mg/kg (kinnow mandarin), K contents of seeds varied between 7007 mg/kg (Orlando orange) and 10334 mg/kg (kinnow mandarin). Glucose and fructose contents of citrus seed samples varied between 3.75 g/kg and 5.75 g/kg, and 4.09 g/kg and 6.03 g/kg. Palmitic, oleic and linoleic acids were established as dominant fatty acids. Palmitic, oleic and linoleic acid contents of citrus seed oils varied between 19.6% (Kütdiken lemon) and 26.2% (pineapple orange), 21.3% (kinnow mandarin) and 31.4% (Kütdiken lemon) and 32.3% (Kütdiken lemon) and 43.7% (kinnow mandarin), respectively. The total amount of tocopherols of Turkish citrus oil varied between 0.5 mg/100 g (Fremont mandarin) and 18.8 mg/100 g (bitter orange).

  18. Physico-Chemical Properties, Antioxidant Activity and Mineral Contents of Pineapple Genotypes Grown in China

    Directory of Open Access Journals (Sweden)

    Xin-Hua Lu

    2014-06-01

    Full Text Available The fruit physico-chemical properties, antioxidant activity and mineral contents of 26 pineapple [Ananas comosus (L. Merr.] genotypes grown in China were measured. The results showed great quantitative differences in the composition of these pineapple genotypes. Sucrose was the dominant sugar in all 26 genotypes, while citric acid was the principal organic acid. Potassium, calcium and magnesium were the major mineral constituents. The ascorbic acid (AsA content ranged from 5.08 to 33.57 mg/100 g fresh weight (FW, while the total phenolic (TP content varied from 31.48 to 77.55 mg gallic acid equivalents (GAE/100 g FW. The two parameters in the predominant cultivars Comte de Paris and Smooth Cayenne were relative low. However, MD-2 indicated the highest AsA and TP contents (33.57 mg/100 g and 77.55 mg GAE/100 g FM, respectively, and it also showed the strongest antioxidant capacity 22.85 and 17.30 μmol TE/g FW using DPPH and TEAC methods, respectively. The antioxidant capacity of pineapple was correlated with the contents of phenolics, flavonoids and AsA. The present study provided important information for the further application of those pineapple genotypes.

  19. Effect of biomass feedstock chemical and physical properties on energy conversion processes: Volume 2, Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Butner, R.S.; Elliott, D.C.; Sealock, L.J., Jr.; Pyne, J.W.

    1988-12-01

    This report presents an exploration of the relationships between biomass feedstocks and the conversion processes that utilize them. Specifically, it discusses the effect of the physical and chemical structure of biomass on conversion yields, rates, and efficiencies in a wide variety of available or experimental conversion processes. A greater understanding of the complex relationships between these conversion systems and the production of biomass for energy uses is required to help optimize the complex network of biomass production, collection, transportation, and conversion to useful energy products. The review of the literature confirmed the scarcity of research aimed specifically at identifying the effect of feedstock properties on conversion. In most cases, any mention of feedstock-related effects was limited to a few brief remarks (usually in qualitative terms) in the conclusions, or as a topic for further research. Attempts to determine the importance of feedstock parameters from published data were further hampered by the lack of consistent feedstock characterization and the difficulty of comparing results between different experimental systems. Further research will be required to establish quantitative relationships between feedstocks and performance criteria in conversion. 127 refs., 4 figs., 7 tabs.

  20. Anti-Inflammatory Properties and Chemical Characterization of the Essential Oils of Four Citrus Species.

    Directory of Open Access Journals (Sweden)

    Jorge Luis Amorim

    Full Text Available Citrus fruits have potential health-promoting properties and their essential oils have long been used in several applications. Due to biological effects described to some citrus species in this study our objectives were to analyze and compare the phytochemical composition and evaluate the anti-inflammatory effect of essential oils (EO obtained from four different Citrus species. Mice were treated with EO obtained from C. limon, C. latifolia, C. aurantifolia or C. limonia (10 to 100 mg/kg, p.o. and their anti-inflammatory effects were evaluated in chemical induced inflammation (formalin-induced licking response and carrageenan-induced inflammation in the subcutaneous air pouch model. A possible antinociceptive effect was evaluated in the hot plate model. Phytochemical analyses indicated the presence of geranial, limonene, γ-terpinene and others. EOs from C. limon, C. aurantifolia and C. limonia exhibited anti-inflammatory effects by reducing cell migration, cytokine production and protein extravasation induced by carrageenan. These effects were also obtained with similar amounts of pure limonene. It was also observed that C. aurantifolia induced myelotoxicity in mice. Anti-inflammatory effect of C. limon and C. limonia is probably due to their large quantities of limonene, while the myelotoxicity observed with C. aurantifolia is most likely due to the high concentration of citral. Our results indicate that these EOs from C. limon, C. aurantifolia and C. limonia have a significant anti-inflammatory effect; however, care should be taken with C. aurantifolia.