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Different Temperatures (different + temperature)
Terms modified by Different Temperatures Selected AbstractsEntrainment Rate of Coarse Particles at Different Temperatures in Gas Fluidized BedsTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2007Jeong-Hoo Choi Abstract Based on available experimental data, an empirical relationship is developed for the entrainment rate of coarse particles at the exit of gas-fluidized beds, including the effects of fine particles in the bed, temperature, gas velocity, particle size and density, and column size. It predicts well the influence of fine particles on the entrainment rate of coarse particles, taking into account the momentum of the fine particles and the effect of superficial gas velocity. It also accounts well for the influence of temperature at different solid densities and gas velocities. À partir de données expérimentales disponibles, on a mis au point une relation empirique pour la vitesse d'entraînement des grosses particules à la sortie des lits fluidisés de gaz, incluant les effets des particules fines dans le lit, la température, la vitesse de gaz, la taille et la masse volumique des particules ainsi que la dimension de la colonne. Cette relation prédit bien l'influence des particules fines sur la vitesse d'entraînement des grosses particules, en tenant compte de la quantité de mouvement des particules fines et de l'effet de la vitesse de gaz superficielle. Elle prend bien en compte également l'influence de la température à différentes masses volumiques de solides et vitesses de gaz. [source] An application of the J-Q model for estimating cleavage stress in the brittle-to-ductile transitionFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 6 2001C. A. J. Miranda A recent model was proposed by the authors to predict cleavage failure for steels based on a weak link mechanism and a crack tip stress field modified for planar constraint by the J,Q theory. The model uses the distribution of toughness results at a single temperature to predict a toughness distribution at a different temperature and/or geometry. In this model a material cleavage stress is needed to predict when the weak link fracture is triggered. This cleavage stress is a key input for the application of the model but it is not a property that is routinely measured and it is hence not available for most steel alloys. In this paper, a method to estimate the average value of the cleavage stress is presented, based on a characteristic of the model to predict cleavage failure. Examples of cleavage stress are given for several steels and these results are used to predict the toughness distributions for structural component models. [source] Qualitative and quantitative responses of Diabroticina (Coleoptera: Chrysomelidae) to cucurbit extracts linked to species, sex, weather and deployment methodJOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2008G. Cabrera Walsh Abstract Toxic baits and traps for Diabroticina, based on bitter cucurbit extracts, have been utilized for a number of years with inconsistent results. Four species of bitter Cucurbitaceae were compared in the field for their attractancy to species of Diabroticina in Argentina and the United States. The comparisons were made with polyester fabrics treated with known volumes of different cucurbit extracts, against a standard cucurbit extract of bitter Hawkesbury watermelon (Citrullus lanatus (Thunberg) Matsumura and Nakai). The factors evaluated were: the attractancy of the different extracts in terms of beetle numbers, species and sex of the Diabroticina caught; influence of different fabrics on such attraction; and influence of several weather variables on the catches. The most attractive species was Cayaponia bonariensis (Miller) Martinez Crovetto, however, practical considerations indicated that Cucumis myriocarpus Naudin and Hawkesbury watermelon may be better choices from the commercial perspective. No single weather factor could explain the catches throughout the sample range, but different temperature and barometric pressure ranges provided some predictive value. Although the susceptibility to weather conditions and a strong male dominance in the catches raise the question of the usefulness of cucurbitacins as the main component in toxic baits or traps, these drawbacks may prove to be less important in widespread bait applications and Diabroticina management in vegetable crops. [source] Impact of curing temperature on microstructures and properties of isobutylene,isoprene rubber/clay nanocompositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008Yong-Lai Lu Abstract In this work, the influence of curing temperature on microstructures of isobutylene,isoprene rubber/clay nanocomposites (IIRCNs) prepared by melt compounding was characterized using wide-angle X-ray diffraction and TEM. The gas barrier and tensile properties of IIRCN cured under different temperature were examined. The results reveal that high pressure, curing reactions, and reactions of amine intercalants with curing agents together play important roles on determining the final microstructures of cured IIRCNs. Changing curing temperature would dramatically alter intercalated structure, dispersion homogeneity, filler,rubber interaction strength, and crosslinking density of obtained IIRCN, resulting in great difference in final properties. Finally, some suggestions for the preparation of successful RCNs were proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Cryopreservation of vascularized ovary: An evaluation of histology and function in ratsMICROSURGERY, Issue 5 2008Shijie Qi M.D. Cryopreservation of organs has been investigated to sustain the reproductive function of patients undergoing sterilizing chemotherapy and radiotherapy or reproductive surgery. A modified protocol for whole organ cryopreservation was described and the outcome of cryopreservative ovaries was evaluated, and apoptosis of cryopreservative cells stored for different time period and the viability of cryopreserved cells stored at different temperature was examined in rats. Lewis rat ovarian grafts were perfused for 30 min at 0.35 ml/min with M2 medium containing 0.1M fructose and increasing concentrations of 0,1.5M dimethylsulfoxide, cooled to ,140°C controlled by a computerized program, and stored in liquid nitrogen (,196°C) for 24 hours. After being thawed, ovaries were transplanted to syngeneic recipients after bilateral oophorectomy. Graft functions were monitored postoperatively. The major findings were that: 1) A 100% survival rate of rat ovaries was achieved in this study. Ovarian hormone secretion recovered in 80% rats which had received cryopreservative ovarian grafts. Postoperative serum estradiol levels in the cryopreservative graft group were lower than in the sham surgery control, but much higher than in the bilateral oophorectomy group. 2) Histological examination of cryopreservative ovarian grafts showed preantral and antral follicles. Two gestations were obtained. 3) Estradiol levels remained low in ovariectomized rats while in the oophorectomized rats given cryopreservative ovarian grafts levels started to rise after 14 ± 3 days. 4) The average viability in the cells from cryopreservative ovary organ (,196°C) was about 71 ± 18% compared to 90 ± 9% of fresh cells. This success should encourage further improvement of cryopreservative techniques for large organs. © 2008 Wiley-Liss, Inc. Microsurgery, 2008. [source] Hydrogenolysis of glycerol with FeCo macrocyclic complex bonded to Raney Nickel support under mild reaction conditionsTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2010K. A. Anand Abstract The hydrogenolysis of dilute glycerol solution to 1,2-propanediol was studied in the presence of heterogeneous catalyst (FeCoL/Raney Nickel) having a heterodinuclear FeCo macrocyclic complex ionically bonded to Raney Nickel. Studies on the stability of the complex bonded to the support were carried out at different temperature as well as the effect of solvent to confirm that it was stable up to 600°C and 100,h of refluxing. In the hydrogenolysis of glycerol, the temperature has been varied from 165 to 220°C with an initial hydrogen pressure 0.35,MPa and the conversion increases from 1% to 36% with no gases evolving in this temperature range. The major product is 1,2-propanediol which is formed with 80% selectivity. The initial water content (20,60%) in the feed was also varied and it was found that the conversion and yield of 1,2-propanediol increases when the water content increases. Based on literature, a kinetic model was proposed and optimal rate constants determined using Genetic Algorithm (GA). On a étudié l'hydrogénolyse d'une solution diluée de glycérol solution en 1,2-propanediol, en présence d'un catalyseur hétérogène (FeCoL/nickel de Raney) ayant un complexe macrocyclique hétérodinucléaire de FeCo ioniquement lié au nickel de Raney. Des études sur la stabilité du complexe lié au soutien ont été effectuées à différentes températures et on a étudié aussi l'effet du solvant pour confirmer qu'il était stable jusqu'à 600 °C et 100 h de reflux. Dans l'hydrogénolyse du glycérol, la température variait de 165 à 220°C avec une pression initiale d'hydrogène de 0,35 MPa et la conversion augmente de 1% à to 36% sans évolution des gaz dans cet intervalle de température. Le produit majeur est le 1,2-propanediol, lequel est formé avec une sélectivité de 80%. Le contenu d'eau initial (20% à 60%) dans l'alimentation variait également et on a conclu que la conversion et le rendement de 1,2-propanediol augmentait avec les augmentations de contenu d'eau. En se basant sur la littérature, un modèle cinétique a été proposé et des constantes de taux optimal ont été déterminées en utilisant un algorithme génétique. [source] Spectroscopic studies of charge transfer complexes of meso -tetra- p -tolylporphyrin and its zinc complex with some aromatic nitro acceptors in different organic solventsAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2007Mohamed E. El-Zaria Abstract The charge transfer complex (CTC) formation of 5,10,15,20-tetra(p -tolyl)porphyrin (TTP) and zinc 5,10,15,20-tetra(p -tolyl)porphyrin with some aromatic nitro acceptors such as 2,4,6-trinitrophenol (picric acid), 3,5-dinitrosalicylic acid, 3,5-dinitrobenzoic acid (DNB) and 2,4-dinitrophenol (DNP) was studied spectrophotometrically in different organic solvents at different temperatures. The spectrophotometric titration, Job's and straight line methods indicated the formation of 1:1 CTCs. The values of the equilibrium constant (KCT) and molar extinction coefficient (,CT) were calculated for each complex. The ionization potential of the donors and the dissociation energy of the charge transfer excited state for the CTC in different solvents was also determined and was found to be constant. The spectroscopic and thermodynamic properties were observed to be sensitive to the electron affinity of the acceptors and the nature of the solvent. No CT band was observed between Zn-TTP as donor and DNP or DNB as acceptors in various organic solvents at different temperature. Bimolecular reactions between singlet excited TTP (1TTP*) and the acceptors were investigated in solvents with various polarities. A new emission band was observed. The fluorescence intensity of the donor band decreased with increasing the concentration of the acceptor accompanied by an increase in the intensity of the new emission. The new emission of the CTCs can be interpreted as a CT excited complex (exciplex). Copyright © 2007 John Wiley & Sons, Ltd. [source] Physiological responses of pink abalone Haliotis corrugata (Gray, 1828) exposed to different combinations of temperature and salinityAQUACULTURE RESEARCH, Issue 7 2010Zarina Medina Romo Abstract Physiological responses of pink abalone Haliotis corrugata were determined under different temperature and salinity conditions. Oxygen consumption rate was not affected by temperature and salinity. Ammonium excretion of pink abalone was inversely related to salinity. The O:N ratio indicated that abalone maintained in lower salinities had an interval of 4.9,7.7, which is indicative of a protein-dominated metabolism, whereas the O:N in 35, was 28.8,35.5 for both temperatures, suggesting that carbohydrates were used as energy substrate. Haemolymph osmolality of abalone exposed to 20 and 24 °C was slightly hyperiso-osmoconformic in salinity ranges of 20,35,. The results of this study suggested that for optimized culture, pink abalone should be cultivated at 24 °C at a salinity of 35,. [source] Purification and partial characterization of glutathione S -transferase from insecticide-resistant field populations of Liposcelis paeta Pearman (Psocoptera: Liposcelididae)ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2009Shuang Wu Abstract Enzymes that possess glutathione S-transferase (GST) activity were purified to homogeneity by glutathione-agarose affinity chromatography from three field populations of Liposcelis paeta (Pearman). These populations were collected from Nanyang city of Henan Province (NY), Wuzhou (WZ) and Hezhou (HZ) cities of Guangxi Province, China, and had different susceptibilities to dichlorvos [LC50s of the NY (281.48,mg/m2), the WZ (285.07,mg/m2), and the HZ (243.52,mg/m2), respectively]. The specific activities of purified enzymes from these three populations increased 32.24-, 99.81-, and 42.52-fold, respectively. Kinetic analyses showed that the catalytic activity of purified GST from NY population towards GSH was much higher than the others, while WZ population reached the highest in V. SDS,polyacrylamide electrophoresis revealed that the purified GST had two subunits with a molecular mass of 23.31 and 20.43,kDa for NY, 53.14 and 20.13,kDa for WZ, and 50.79 and 19.42,kDa for HZ, respectively. The in vitro inhibition studies of GSTs indicated that three kinds of insecticides (chlorpyrifos, carbosulfan, and cypermethrin) and five metallic ions (Zn2+, Ba2+, Ca2+, Hg2+, Mn2+, and Mg2+) all possessed inhibitory effects on purified GST, and ethacrynic acid (EA, a specific inhibitor of GST) expressed inhibitory effects. In the bioassay, three populations of L. paeta had different susceptibilities to different insecticides, even after they were reared on diets consisting of 25% EA. The GST activities of L. paeta from different areas also showed different temperature and pH stabilities. The differences in GST among the three populations may be attributed partially to the differences in control practices for psocids between Henan and Guangxi Provinces. © 2009 Wiley Periodicals, Inc. [source] Comparison of the Surface and Underground Natural Gas Occurrences in the Tazhong Uplift of the Tarim BasinACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 5 2010TIAN Jun Abstract: The oil, gas and water volumes revealed by the productivity of exploratory wells do not reflect the actual underground situations. Under the geologic conditions, a certain amount of dissolved natural gas is stored in oil or water. Based on the production test data of exploratory wells in the Tazhong uplift of the Tarim basin, this paper discusses in detail the differences in occurrence and distribution featrues between the surface and underground natural gases; presents a restoration of the surface gas occurrence to actual underground geologic conditions according to the dissolubility of natural gas under different temperature, pressure and medium conditions; and classifies the natural gas into three states, i.e. the oversaturated, saturated and undersaturated, according to its relative content underground. Through a comparative analysis of the differences in surface and underground occurrences of natural gas, it discusses the hydrocarbon reservoir formation mechanism and distribution rules, thereby providing guidances as new methods and technologies for the prediction of potential natural gas reservoir distribution in the study area. [source] Cobalt(II) salen complex with two aza-crown pendants and its analogues as synthetic oxygen carriersCHINESE JOURNAL OF CHEMISTRY, Issue 6 2004Xing-Yue Wei Abstract Salen with two aza-crown ether pendants H2L1 and its analogues H2L2- H2L4 were successfully synthesized starting from benzo-10-aza-15crown-5 (BN15C5) or morpholine. Their structures were characterized by IR, MS, 1H NMR and elemental analysis, and were confirmed by X-ray diffraction analysis of H2L1. Moreover, the saturated oxygen uptake of their cobalt(II) complexes CoL1- CoL4 in diethyleneglycol dimethyl ether was determined at different temperature. The oxygenation contants (KO2 ) and thermodynamic parameters (,H° and ,S°) were calculated. The modulation of O2 -binding capabilities by pendant substituents were investigated as compared with the parent Schiff base complex CoL5 (CoSalen). The results indicate that the dioxygen affinities of CoL have been much more enhanced by aza-crown pendants than that by morpholino pendants, and the O2 -binding capabilities of CoL1 and CoL2 with aza-crown pendants would also be enhanced by adding alkali metal cations. [source] Fluid Model of a Sheath Formed in Front of an Electron Emitting Electrode Immersed in a Plasma with Two Electron TemperaturesCONTRIBUTIONS TO PLASMA PHYSICS, Issue 2 2005T. Gyergyek Abstract The formation of a sheath in front of a negatively biased electrode (collector) that emits electrons is studied by a one-dimensional fluid model. Electron and ion emission coefficients are introduced in the model. It is assumed that the electrode is immersed in a plasma that contains energetic electrons. The electron velocity distribution function is assumed to be a sum of two Maxwellian distributions with two different temperatures, while the ions and the emitted electrons are assumed to be monoenergetic. The condition for zero electric field at the collector is derived. Using this equation the dependence of electron and ion critical emission coefficients on various parameters - like the ratio between the hot and cool electron density, the ratio between hot and cool electron temperature and the initial velocity of secondary electrons - is calculated for a floating collector. A modification of the Bohm criterion due to the presence of hot and emitted electrons is also given. The transition between space charge limited and temperature limited electron emission for a current-carrying collector is also analyzed. The critical potential, where this transition occurs, is calculated as a function of several parameters like the Richardson emission current, the ratio between the hot and cool electron density, the ratio between hot and cool electron temperature and the initial velocity of secondary electrons. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Structural, optical and photoconductive properties of electron beam evaporated CdSxSe1-x filmsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 4 2010K. Sivaramamoorthy Abstract CdSxSe1-x films were deposited by the electron beam evaporation technique on glass substrates at different temperatures in the range 30 , 300 °C using the laboratory synthesized powders of different composition. The films exhibited hexagonal structure and the lattice parameters shifted from CdSe to CdS side as the composition changed from CdSe to CdS side. The bandgap of the films increased from 1.68 to 2.41 eV as the concentration of CdS increased. The root-mean-roughness (RMS) values are 3.4, 2.6, 1.2 and 0.6 nm as the composition of the films shifted towards CdS side. The conductivity varies from 30 ,cm -1 to 480 ,cm -1 as the ,x' value increases from 0 to 1. The films exhibited photosensitivity. The PL spectrum shifts towards lower energies with decreasing x, due to the decrease of the fundamental gap with Se composition. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Growth of single-grain GdBa2Cu3O7-x superconductors by top seeded infiltration and growth techniqueCRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2010Guo-Zheng Li Abstract The top seeded infiltration and growth technique (TSIG) is an effective way for the preparation of bulk REBa2Cu3O7-x (RE-123, where RE denotes rare earth) with finely dispersed RE2BaCuO5 (RE-211) particles compared to the conventional melt growth (MG) method. The nucleation temperature and the ending growth temperature are the most important parameters need to be optimized during the preparation of RE-123 bulks by the TSIG process. In this paper, the effects of these parameters on the growth of single-grain GdBa2Cu3O7-x (GdBCO) superconductors have been investigated experimentally. It is found that the temperature for the growth of single-grain GdBCO is in the region between 1040 °C and 1015 °C. In addition, the relation between growth rate and supercooling has been investigated in detail. The combined techniques of SEM and EDS were used to study the microstructure of the samples grown at different temperatures. Based on this, a two-step slow cooling method during the crystallization process is proposed for the fabrication of RE-123 bulks. Finally, the single-grain GdBCO samples of the diameters 20 mm and 30 mm were fabricated successfully by the TSIG technique, with the slow-cooling process in the temperature window 1030 °C,1020 °C for 60 h and 100 h respectively. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Work-hardening characteristics of Zn-Ti alloy single crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 2 2010G. Boczkal Abstract Shear stress , shear strain curves of 0.14 at.%Ti alloyed Zn single crystals were measured in compression at different temperatures and shear strain rates. The work-hardening coefficient for basal slip increases with decreasing temperature and increasing shear strain rate. The work-hardening characteristics are compared with those reported for Zn single crystals with different constituents and purities. It is discussed with respect to the interaction of dislocations with dislocations, vacancies, vacancy agglomerates and solute atoms. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Influence of the substrate temperature on the structural, optical, and electrical properties of tin selenide thin films deposited by thermal evaporation methodCRYSTAL RESEARCH AND TECHNOLOGY, Issue 1 2010N. Kumar Abstract Thin films of tin selenide (SnSe) were deposited on sodalime glass substrates, which were held at different temperatures in the range of 350-550 K, from the pulverized compound material using thermal evaporation method. The effect of substrate temperature (Ts) on the structural, morphological, optical, and electrical properties of the films were investigated using x-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission measurements, and Hall-effect characterization techniques. The temperature dependence of the resistance of the films was also studied in the temperature range of 80-330 K. The XRD spectra and the SEM image analyses suggest that the polycrystalline thin films having uniform distribution of grains along the (111) diffraction plane was obtained at all Ts. With the increase of Ts the intensity of the diffraction peaks increased and well-resolved peaks at 550 K, substrate temperature, were obtained. The analysis of the data of the optical transmission spectra suggests that the films had energy band gap in the range of 1.38-1.18 eV. Hall-effect measurements revealed the resistivity of films in the range 112-20 , cm for films deposited at different Ts. The activation energy for films deposited at different Ts was in the range of 0.14 eV-0.28 eV as derived from the analysis of the data of low-temperature resistivity measurements. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of annealing on the structural, electrical and optical properties of nanostructured TiO2 thin filmsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2009S. Sankar Abstract Nanostructured titanium dioxide thin films were prepared using reactive pulsed laser ablation technique. Effects of annealing on the structural, morphological, electrical and optical properties are discussed. The structural, electrical and optical properties of TiO2 films are found to be sensitive to annealing temperature and are described with GIXRD, SEM, AFM, UV-Visible spectroscopy and electrical studies. X-ray diffraction studies showed that the as-deposited films were amorphous and at first changed to anatase and then to rutile phase with increase of annealing temperature. Optical constants of these films were derived from the transmission spectra and the refractive index dispersion of the films, subjected to annealing at different temperatures, is discussed in terms of the single oscillator-Wemple and Didomenico model. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of Pb on the properties of Sr2YRu1-xCuxO6 crystals grown from PbO-PbF2 solutions at high temperaturesCRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2007S. M. Rao Abstract Single crystals of Sr2YRu1-xCuxO6 with x=0 and x=0.1 were grown using PbO-PbF2 based solutions at different temperatures in the range 1150,1350°C. The influence of Pb from the solutions and the Cu from the solid solutions of Sr2YRu1-xCuxO6 on the resulting crystals was studied using microstructure and magnetic property measurements. The peaks in the powder X-ray diffraction patterns and Raman spectra do not change in the case of x=0 crystals but shift in the presence of Cu. A diamagnetic transition indicative of superconductivity was observed in the presence of Cu and an antiferromagnetic behavior with x=0. Based on these results it is concluded that Pb may not be incorporated in the crystals and even if it does the influence is not observed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Photoelectrical properties of crystalline titanium dioxide thin films after thermo-annealingCRYSTAL RESEARCH AND TECHNOLOGY, Issue 5 2007R. Sathyamoorthy Abstract This paper reports the photoelectrical properties of sol gel derived titanium dioxide (TiO2) thin films annealed at different temperatures (425-900°C). The structure of the as-grown film was found to be amorphous and it transforms to crystalline upon annealing. The trap levels are studied by thermally stimulated current (TSC) measurements. A single trap level with activation energy of 1.5 eV was identified. The steady state and transient photocurrent was measured and the results are discussed on the basis of structural transformation. The photocurrent was found to be maximum for the films annealed at 425°C and further it decreases with annealing at higher temperatures. The photoconduction parameters such as carrier lifetime, lifetime decay constant and photosensitivity were calculated and the results are discussed as a function of annealing temperature. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Growth and properties of an organometallic nonlinear optical crystal: bis(isothiocyanato)-bis(4-methylpyridine)zinc(II) (Zn(SCN)2(C6H7N)2)CRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2006L. Y. Zhu Abstract Bis(isothiocyanato)-bis(4-methylpyridine)zinc(II)(Zn(SCN)2(C6H7N)2), (abbreviated as ZBNC) single crystals of optical quality have been grown from acetone solution by the slow temperature-lowering method. Its solubilities at different temperatures in acetone were measured. The X-ray powder diffraction (XRPD) spectroscopy of ZBNC crystal was performed at room temperature. The second harmonic generation (SHG) efficiency was determined by powder technique of Kurtz and Perry using Nd:YAG laser, which is equivalent to KDP crystal. The thermal decomposition process was characterized by thermal gravity and differential thermal analysis (TG\DTA). The specific heat of the crystal is 1440.67 J/mol·K at 325 K. The IR spectrum was recorded in the 500,3500 cm,1 region, using KBr pellets on a Nicolet 170sx FT-IR spectrometer. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Determination of lattice parameters and thermal expansion of CuGe2P3 + 0.2 Ge3P4 at elevated temperaturesCRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2006G. Bhikshamaiah Abstract CuGe2P3 is a p-type semiconductor with zincblende structure. Ge3P4 is soluble up to 35 mole% in CuGe2P3. Lattice parameters of CuGe2P3 + 0.2 Ge3P4 have been determined at elevated temperatures from room temperature to 873 K using the x-ray diffraction profiles (111), (200), (220), (311), (222), (400), (331), (420), (422) and (511) obtained from high temperature diffractometer. It is found that the lattice parameter increases linearly from 0.53856 nm at RT to 0.54025 nm at 873 K. The data on lattice parameter is used and coefficient of lattice thermal expansion of CuGe2P3 +0.2 Ge3P4 was determined at different temperatures. It is found that the coefficient of thermal expansion of CuGe2P3 +0.2 Ge3P4 is 5.48 x 10 -6 K -1 and is independent of temperature. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Growth of tin oxide nanocrystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 10-11 2005L. Zanotti Abstract Functional oxides are presently much investigated as regards not only their basic properties, but also their actual and potential applications. Tin oxides appear particularly interesting when grown in nanowire shape (SnO2 -NW) because of their electronic- and sensor-device applications. In this paper the results of a systematic study on nucleation and growth of SnO2 -NWs, when an open-tube vapor-transport technique is employed, are reported and discussed. The vapor transport conditions have been investigated in greater detail and for the first time a growth model is proposed. Functional tests at different temperatures and gaseous compositions have proved that the SnO2 -NW are suitable for the preparation of highly-sensitive and stable gas sensors. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Microstructural, thermal, and electrical properties of Bi1.7V0.3Sr2Ca2Cu3Ox glass-ceramic superconductorCRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2004T. S. Kayed Abstract A glass-ceramic Bi1.7V0.3Sr2Ca2Cu3Ox superconductor was prepared by the melt-quenching method. The compound was characterized by scanning electron microscopy, x-ray diffraction, differential thermal analysis, current-voltage characteristics, transport resistance measurements, and Hall effect measurements. Two main phases (BSCCO 2212 and 2223) were observed in the x-ray data and the values of the lattice parameters quite agree with the known values for 2212 and 2223 phases. The glass transition temperature was found to be 426 °C while the activation energy for crystallization of glass has been found to be Ea = 370.5 kJ / mol. This result indicates that the substitution of vanadium increased the activation energy for the BSCCO system. An offset Tc of 80 K was measured and the onset Tc was 100 K. The Hall resistivity ,H was found to be almost field-independent at the normal state. A negative Hall coefficient was observed and no sign reversal of ,H or RH could be noticed. The mobility and carrier density at different temperatures in the range 140-300 K under different applied magnetic fields up to 1.4 T were also measured and the results are discussed. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of temperature and storage media on human periodontal ligament fibroblast viabilityDENTAL TRAUMATOLOGY, Issue 3 2010Beatriz Dulcineia Mendes Souza The purpose of this study was to compare the effectiveness of several storage media to preserve cultured periodontal ligament fibroblasts (PDLF) under different temperatures. The media tested were: sterile Hank's balanced salt solution (sHBSS), non-sterile HBSS (nHBSS), skimmed milk, Save-A-Tooth®, Minimum Essential Medium (MEM) and water (negative control). MEM at 37°C was used as positive control. PDLF were obtained from explants of extracted healthy human teeth. Plates containing confluent PDLF were soaked in the various media for 3, 6, 24, 48 and 72 h at 37°C and 20°C. After incubation, viability of the cells was determined using the tetrazolium salt-based colorimetric (MTT) assay and the Trypan Blue exclusion test after 6, 24, 48 and 72 h of incubation at 20°C. The results were analyzed statistically using Kruskal,Wallis, Scheffé and Mann,Whitney (, = 5%) tests. Results from the MTT assay at 37°C and 20°C showed that skimmed milk was the best storage medium for up to 24 and 48 h, respectively, followed by nHBSS and sHBSS. Results from the Trypan Blue exclusion test showed that the best storage media were milk, sHBSS and nHBSS, with no statistical differences, for any time period. The Save-A-Tooth® had a detrimental effect on cells after 24 h. The influence of temperature on the effectiveness of the storage media tested showed at 20°C a decreasing order of efficacy as follows: milk > sHBSS and nHBSS > MEM > Save-A-Tooth® > water while at 37°C it was: MEM > nHBSS > milk > sHBSS > Save-A-Tooth® > water. In conclusion, incubation temperature altered the effectiveness of the storage media and skimmed milk at 20°C was better than HBSS in maintaining PDLF viability. [source] Validation of daily increment formation and the effects of different temperatures and feeding regimes on short-term otolith growth in Australian smelt Retropinna semoniECOLOGY OF FRESHWATER FISH, Issue 2 2008Z. Tonkin Abstract,,, To aid otolith interpretation of wild fish, we conducted a laboratory study using metalarval Australian smelt (Retropinna semoni) collected from the Murray River, to examine daily increment deposition and the effects of different temperatures and feeding regimes on otolith growth. Daily increment deposition was confirmed by comparing the number of increments from an oxytetracycline mark with the known number of days from marking. After holding fish at two temperature levels and three feeding rates, both food density and temperature were found to have a significant effect on otolith growth, with food density having the greatest influence. Overall trends in final lengths and condition of fish were well represented by recent otolith growth. The results of the experiment have implications for estimating growth histories and its relationship to various environmental conditions. [source] A Contribution to the Study of the Adsorption of s -Triazine Herbicides on Glassy Carbon Electrodes by Differential-Capacity MeasurementsELECTROANALYSIS, Issue 6 2010S. Pintado Abstract Measurements of differential capacity vs. potential have been made for a series of s -triazine herbicides at different concentrations. In all cases the decrease in capacity was independent of the applied potential, so the adsorption is also independent of the potential. From the measurements it can be established that the adsorption follows Langmuir type isotherms. Adsorption constants were obtained for the different herbicides at 25,°C (simetryn, simazine, terburyn and prometon) as well as those to simetryn at different temperatures, from which the adsorption enthalpy of this herbicide was calculated being its value of 17.5,kJ mol,1. [source] Determination of the binding constants of modafinil enantiomers with sulfated ,-cyclodextrin chiral selector by capillary electrophoresis using three different linear plotting methodsELECTROPHORESIS, Issue 17 2010Khaldun M. Al Azzam Abstract Binding constants for the enantiomers of modafinil with the negatively charged chiral selector sulfated-,-CD (S-,-CD) using CE technique is presented. The calculations of the binding constants employing three different linearization plots (double reciprocal, X -reciprocal and Y -reciprocal) were performed from the electrophoretic mobility values of modafinil enantiomers at different concentrations of S-,-CD in the BGE. The highest inclusion affinity of the modafinil enantiomers were observed for the S -enantiomer,S-,-CD complex, in agreement with the computational calculations performed previously. Binding constants for each enantiomer,S-,-CD complex at different temperatures, as well as thermodynamic parameters for binding, were calculated. Host,guest binding constants using the double reciprocal fit showed better linearity (r2>0.99) at all temperatures studied (15,30°C) and compared with the other two fit methods. The linear van't Hoff (15,30°C) plot obtained indicated that the thermodynamic parameters of complexation were temperature dependent for the enantiomers. [source] Analysis of integral membrane proteins by heat gel-embedment combined with improved in-gel digestionsELECTROPHORESIS, Issue 23 2009Jian Zhou Abstract Analysis of integral membrane proteins (IMPs) presents a special challenge because of their hydrophobic nature and low abundance. Here, a new method was developed, which involved heat gel-embedment and improved in-gel digestion of the proteins. Membrane protein lysate containing detergents was mixed with acrylamide solution and the proteins were embedded when the gel polymerized. For comparison, the protein embedment was made at different temperatures (25, 35 or 45°C), and the in-gel digestions were performed in the presence of 0.1% RapiGest reagent (ALS), 0.1% sodium deoxycholate and 10% ACN, respectively. The resultant peptides were extracted and analyzed by capillary liquid chromatography coupled with tandem mass spectrometry. Compared with that at 25°C, gel-embedment at 45°C improved the protein embedment and thus protein identification, with the identified IMPs increased by 27%. 0.1% sodium deoxycholate was more efficient than 0.1% ALS and 10% ACN in terms of improving the digestion and tryptic digest recovery of the gel-embedded proteins particularly the hydrophobic IMPs. Out of the 326 IMPs identified by heat gel-embedment combined with improved in-gel digestion strategies, 149 (46%) proteins had at least two mapped transmembrane domains. These results indicate that our newly developed protocol could facilitate the high throughput analysis of integral membrane proteome. [source] Helical- and ahelical-dependent chiral recognition mechanisms in capillary electrophoresis using amylose as the selectorELECTROPHORESIS, Issue 8 2009Weili Wei Abstract The present study discovered that helical structures of amylose were not always responsible for its chiral recognition abilities in CE. Several enantiomers with different structures were selected as models. Based on ultraviolet,visible spectroscopy and 13C NMR measurements, it was found that helical structures were gradually destroyed by temperature elevation and almost entirely transformed to extended ahelical structures above 60°C. Then, CE and 1H NMR chiral recognitions were investigated at different temperatures; chiral selectivity of the enantiomers varied in two different ways. Summarily, helical structures were necessary only for chiral separations of the enantiomers with small (<0.78,nm) and flexible molecular structures. However, for the gauche enantiomers (>0.78,nm) with high steric hindrances over their chiral centers, ahelical structures alone can realize chiral recognitions. By using iodine as a helix including competitor, it was further proved that helical structures functioned through the inclusive complexations only in the chiral separations of small enantiomers and had no effect for the others. The underlying mechanisms of the functions of helical and ahelical structures in molecular level were discussed as well. [source] Development of emulsion from rhizobial fermented starch industry wastewater for application as Medicago sativa seed coatENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 3 2010Rojan Pappy John Abstract Starch industry wastewater was efficiently employed for the production of Sinorhizobium meliloti and the concentrated culture was used for the development of a biofertilizer formulation. Tween-80 (0.02,g/L) acted as the best emulsifier for a Sinorhizobium,canola oil emulsion. The stability of the emulsion and survival of the organism was enhanced by supplementation of xanthan gum at pH 8. The refrigerated condition was most favorable for stability and survival of the microorganism. The survival of microorganism at 4±1°C was 2.78×1010 and 2.01×1010,CFU (colony forming unit)/mL on storage for 1 and 2 months, respectively. The values were higher than the prescribed cell count (×103,CFU/mL) for field application. At 40°C, the survival of bacteria reduced from 3×1010,CFU/mL to 8.1×109 and 8.8×106,CFU/mL in 1 and 2 months, respectively. Emulsion-coated seed was incubated at different temperatures and a cell count of 105,CFU/seed was observed after 2 months of storage at 4°C, which was equal to the highest level of the described requirement (103,105,CFU/seed). Emulsion supplemented with xanthan gum improved the shelf-life under optimized conditions (Sinorhizobium concentrate,,,canola oil (1:1) emulsion with 0.02,g/L Tween-80; storage at pH 8 and temperature 4±1°C) and this emulsion with the required cell count and prolonged viability was used for the pre-inoculation of seed or for in situ soil application. [source] | ||||||||||||||||||||||||||||||||||||||||||||||