نتایج جستجو برای: were 0025 m h2so4
تعداد نتایج: 3824851 فیلتر نتایج به سال:
To suppress methanol crossover in direct methanol fuel cells DMFCs , a Nafion-Bi2V0.75Sb0.25O5.4 composite membrane was prepared by recast method. Oxygen-ion conductive Bi2V0.75Sb0.25O5.4 powders were highly dispersed in a Nafion 117 membrane to physically block methanol crossover and/or chemically oxidize the methanol, which was confirmed by the difference in the methanol diffusion coefficient...
کمبود آهن که عمدتا به صورت کلروز بین رگبرگی در برگ¬های جوان بروز می نماید به عنوان یکی از اختلالات مهم تغذیه ای در سیب به ویژه در خاک¬های آهکی مطرح است که به شدت عملکرد و کیفیت محصول را تحت تاثیر قرار می دهد. ارزیابی وضعیت آهن قابل استفاده برای گیاهان توسط عصاره گیرهای شیمیایی بسیار مهم و ضروری می نماید. در این پژوهش تعداد 27 نمونه خاک از عمق 0 تا 30 و 30 تا 50 سانتیمتری و 27 نمونه برگی از باغا...
Soils have a great potential to accumulate carbon from atmospheric sources, but we possess few quantitative tools to predict and understand the conversion of C from plant sources into stable soil organic matter. Evaluation of present methods used for analyzing the major form of carbon present in plants, carbohydrates, found that development of ‘total carbohydrate’ methods were originally based ...
Transition metal phosphides exhibit high catalytic activity toward the electrochemical hydrogen-evolution reaction (HER) and resist chemical corrosion in acidic solutions. For example, an electrodeposited CoP catalyst exhibited an overpotential, η, of -η < 100 mV at a current density of -10 mA cm-2 in 0.500 M H2SO4(aq). To obtain a chemical description of the material as-prepared and also while...
Military small arms shooting range (SASR) soils are heavily polluted by metals like copper, lead, antimony, and zinc. This study was carried out to define efficient operating conditions to solubilize these metals by a chemical leaching technique. The comparison of different leaching reagents (HCl, H2SO4, CH3COOH, and EDTA) has revealed that sulfuric acid leaching coupled with the addition of so...
in this study, a simple, rapid and selective method was developed for the determination of dexamethasone. the proposed method is based on inhibitory effect of dexamethasone on the oxidation of orange-g by bromate in sulfuric acid media. the reaction was followed spectrophotometrically at 478.5 nm (?max). under optimum experimental conditions, (72.6 ?mol l-1 of orange-g, 0.76 mol l-1 of h2so4, 0...
The structure and stability of mass-selected bisulfate, sulfuric acid, and water cluster anions, HSO4(-)(H2SO4)m(H2O)n, are studied by infrared photodissociation spectroscopy aided by electronic structure calculations. The triply hydrogen-bound HSO4(-)(H2SO4) configuration appears as a recurring motif in the bare clusters, while incorporation of water disrupts this stable motif for clusters wit...
The concentration of [3H]DHA was 1.0 n M . Non-specific binding was defined by the curve-fitting program and it was determined as 29% of total [”IDHA binding. The competition curve fit best to a two-site model (f.’<O.0025), with K , = 4 f 2 nM and K L = 3 f 2 ,UM ( m e a n s + s ~ ~ of three separate competition experiments which were pooled). These values were obtained by setting the affinity ...
Nickel films of 150 nm thickness were deposited on 304 stainless steel and post annealed under flow of nitrogen at different temperatures. The prepared samples were corrosion tested in 1.0 M H2SO4 solution using potentiodynamic polarization technique. Crystallographic and morphological structure of the samples were analysed by X-ray diffraction XRD and atomic force microscopy AFM respectively b...
the present study aimed at investigating the relationship between iranian efl teachers’ classroom management orientations and their teaching styles. additionally, the difference between male and female teachers’ teaching styles and classroom management orientations and their relationship with experience and age were explored. three hundred efl teachers filled in attitudes and beliefs on classro...
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