all analytical methods are generally based on the measurement of a parameter or parameters which are somehow related to the concentration of the species.an ideal analytical method is one in which the concentration of a species can be measured to a high degree precision and accuracy and with a high sensitivity. unfortunately finding such a method is very difficult or sometimes even impossible.in...

heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

1- in a search directed to the reaction of compound)23(the cycloaddition reaction of 1,3- diphenylisobenzofurane)14(with p-benzoquinone)19(,followed by addition of cyclopentadiene was carried out.the specific spacial stracture of its ir,nmr,mass spectra. 2- in another attempt the kinetic stability and behavior of compounds)20(and)23(was studied.the main subject of this study was the highly reve...

the aim of conducting this study was to investigate the foreign language learning needs of undergraduate economics students and business management students in faculties of social sciences of alzahra and azad naragh university. in the study, which was designed on the basis of a qualitative-quantitative basis using interviews and questionnaires, 146 female undergraduate business management as we...

the history of plant’s used for mankind is as old as the start of humankind. initially, people used plants for their nutritional proposes but after the discovery of medicinal properties, this natural ?ora became a useful source of disease cure and health improvement across various human communities. berberis vulgaris is one of the medicinal plants used in iranian traditional medicine. berberis ...

a novel and ultra low cost isfet electrode and measurement system was designed for isfet application and detection of hydronium, hydrazinium and potassium ions. also, a measuring setup containing appropriate circuits, suitable analyzer (advantech board), de noise reduction elements, cooling system and pc was used for controlling the isfet electrode and various characteristic measurements. the t...

fluorescence chemical sensors for the highly sensitive and selective determination of pb2+ , hg2+, co2+ and fe3+ ions in aqueous solutions are described. the ion sensing system was prepared by incorporating lipophilic ligand (l) as a neutral ion-selective fluoroionophore in the plasticized pvc membrane containing sodium tetraphenylborate or potasium tetrakis (p-chlorophenyl) borate as a liphoph...

جهت بهینه سازی شرایط تولید پروتئین هیدرولیز شده (شامل نسبت آنزیم به سوبسترا، دما و زمان) به منظور دستیابی به بالاترین خواص آنتی اکسیدانی، مینس تهیه شده از ضایعات میگوی ببری سبز (penaeus semisulcatus) پس از تعیین درصد پروتئین آن (13%، بر اساس وزن تر) با استفاده از دو پروتئاز تجاری آلکالاز و فلاورزایم بر اساس 18 تیمار تعیین شده با طرح آزمایشات سطح پاسخ برای هر آنزیم، هیدرولیز شده و با خشک کن انجم...