Diheterolevulosan III and IV. The Structure of Diheterolevulosan IV.

the underlying structure of language proficiency and the proficiency level

هدف از انجام این تخقیق بررسی رابطه احتمالی بین سطح مهارت زبان خارجی (foreign language proficiency) و ساختار مهارت زبان خارجی بود. تعداد 314 زبان آموز مونث و مذکر که عمدتا دانشجویان رشته های زبان انگلیسی در سطوح کارشناسی و کارشناسی ارشد بودند در این تحقیق شرکت کردند. از لحاظ سطح مهارت زبان خارجی شرکت کنندگان بسیار با هم متفاوت بودند، (75 نفر سطح پیشرفته، 113 نفر سطح متوسط، 126 سطح مقدماتی). کلا ...

Aqueous complexation of thorium(IV), uranium(IV), neptunium(IV), plutonium(III/IV), and cerium(III/IV) with DTPA.

Aqueous complexation of Th(IV), U(IV), Np(IV), Pu(III/IV), and Ce(III/IV) with DTPA was studied by potentiometry, absorption spectrophotometry, and cyclic voltammetry at 1 M ionic strength and 25 °C. The stability constants for the 1:1 complex of each trivalent and tetravalent metal were calculated. From the potentiometric data, we report stability constant values for Ce(III)DTPA, Ce(III)HDTPA,...

Ion Exchange Column Performance Model for Separation of Zr(IV) and Hf(IV) in Elution Process

A mathematical model of sorption of Zirconium and Hafnium cations mixture and elution of these ions from a cation exchange resin bed is developed. Sulfuric acid is selected as the eluent for selective separation of Zr and Hf in a packed bed of Dowex cation exchange resin. The column model is a dispersed plug flow model,and assumed to consist of randomly packed synthetic and spherical resin ...

Pathology. Parts III and IV

Iii and Iv Structural Studies

The production, isolation and characterization of rancinamycins I, II, III and IV have been described in a preceding communication." These metabolites, which exhibit in vitro activity against Gram-positive and Gram-negative bacteria, are produced by Streptomyces lincolnensis in media depleted of sulfur-containing inorganic or organic compounds. Rancinamycins I, II, III and IV behaved as single ...