نتایج جستجو برای: cation exchange capacity relationships were described by power functions r2087 and 080

تعداد نتایج: 17959500  

Mona Iravaninia S. Rowshanzamir,

In present research work, anion exchange membranes based on quaternized polysulfone with ammonium cation moieties (QAPSF) were prepared by chloromethylation, amination and alkalization. The chloromethylated polysulfone were characterized by 1HNMR spectroscopy and functionalization degree was determined according to peak area integration. Ion transport properties (ionic conductivity, ion exchang...

پایان نامه :0 1374

the research questions were as follows: 1. is there any relationship between the students concious awareness of the form and implications of the conjuncations and their improvement in using appropriate conjunctions? 2. does students knowledge of the from and the implications of the conjunctions help them to produce more coherent writings. 3. does a comparison between english conjunctions and th...

ژورنال: علوم آب و خاک 2009
بیگی هرچگانی, حبیب اله , صالحی, محمدحسن , مهاجر, رضا,

Soil fertility measures such as cation exchange capacity (CEC) may be used in upgrading soil maps and improving their quality. Direct measurement of CEC is costly and laborious. Indirect estimation of CEC via pedotransfer functions, therefore, may be appropriate and effective. Several delineations of two consociation map units consisting of two soil families, Shahrak series and Chaharmahal seri...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this thesis protic and aprotic ammonium-based ionic liquids were synthesized and their surface tensions were measured in the range of 298-373k. the protics are alkyl ammonium-based ils with the carboxylate (formate, acetate, propionate) anion and aprotics are quaternary ammonium-based ils with bis(trifluoromethylsulfonyl)imide anion. capillary rise method was used for surface tension measure...

Journal: :analytical and bioanalytical chemistry research 0
zahra hassanzadeh siahpoosh imam khomeini international university (ikiu), qazvin, iran majid soleimani imam khomeini international university (ikiu), qazvin, iran

this article presents the method of extraction-preconcentration of lead, cadmium, and nickel ions from food samples using the ghezeljeh montmorillonite nanoclay (geleh-sar-shoor) as a new native adsorbent in batch single component systems. the extraction-preconcentration of heavy metals were carried out by applying the solid phase extraction (spe) method followed by atomic absorption spectrosco...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده علوم تربیتی و روانشناسی 1391

the purpose of this study was to examine the status of supervision on departments’ heads at ferdowsi university of mashhad (fum) and realize some applied themes to provide a fit model for supervising departments’ heads in fum. the method was case study under a research category aimed for applied one. using purposive sampling, interviews were conducted with top fum managers, head departments, an...

ژورنال: علوم آب و خاک 2014
ادهمی, ابراهیم , اولیایی, حمیدرضا , حیدرماه, صفورا , نجفی قیری, مهدی ,

Rate of nonexchangeable K release can significantly influence K availability. Kinetics of K+ release was studied by extraction using 0.01 M CaCl2 in 12 surface calcareous soils of Kohgilouye Province. Results showed that cumulative K release ranged from 89.9 to 460.9 mg kg-1(Average 195.4 mg kg-1). Calcium carbonate, nonexchangeable K, cation exchange capacity and mica showed a significant corr...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده ادبیات و علوم انسانی 1391

the present study aimed at exploring cognitions of iranian english teachers within the context of english for academic purposes (eap). to this end, the cognitions of two groups of eap teachers with respect to their pedagogical content knowledge (pck) and their sense of professional identity (pi) were probed. two language teachers and two content instructors who had at least five years of eap te...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده زبانهای خارجی 1391

as polysemy is encountered frequently in english as foreign language. fl learners’ ability to disambiguate polysemous verbs becomes critical to their comprehension in the target language. this thesis, accordingly, investigated how iranian efl learners achieved comprehension of english polysemous verbs by using three different types of cues: (1) elaborated context, (2) semantic frames, and (...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده ادبیات و زبانهای خارجی 1393

abstract in written mode of language, metadiscourse markers are used commonly to help writers in general and academic writers in particular to produce coherent and professional texts. the purpose of the present study was to compare introduction sections of applied linguistics and physics articles regarding their use of interactive and interactional metadiscourse markers based on the model pro...

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