two steps synthetic method for the preparation of a novel emulsion stabilizer called poly(ricineoleic acid-b-ethyleneglycol-b-ricineoleic acid) with average mass molecular weight of 7000 daltons is investigated. in the first step, oligoricineoleic acid with average mass molecular weight of 1800 daltons is synthesized (yield 70%). in the second step, the desired copolymer is  synthesized from th...

Multiobjective Pareto optimal solutions for epoxy semi-batch polymerization process are obtained by adapting nondominated sorting genetic algorithm II (NSGA II). The objective is to produce polymer of maximum possible number average molecular weight (Mn) with a specified value of polydispersity index (PDI) and number average molecular weight in minimum possible time. The M and reaction time a p...

We studied the effectiveness with which various charcoal preparations separate free [3H]pteroylglutamate from that complexed with milk folate binder. We tested, in various concentrations, uncoated charcoals and charcoals coated with dextrans of various molecular weights, or with albumin, hemoglubin, or polyvinylpyrrolidone with an average molecular weight of 40 000. Althouth there was some dist...

background and objectives: molecular typing methods are important and useful tools to assess the transmission, diversity of strains and differentiation between new infections and relapses which can effectively help in controlling infections. the aim of this study was to evaluate the molecular typing methods which have been used in iran. by evaluating the results and discriminatory power of each...

a water soluble polysaccharide, hb-1, with a molecular weight of 23,930, was isolated from radix ranunculi ternati. by hot water extraction, ethanol precipitation, deproteination，ultrafiltration and gel-filtration column chromatography. its sugar composition was determined by glc as glc, ara, and gal in a molar ration of 16.071: 2.722: 1. and the absolute configuration of glc was identified as ...

Samples of Chinese fir were treated with either low-molecular-weight or commercial phenol-formaldehyde (PF) resins. The macroand micromechanical properties of the treated and untreated samples were determined. The average longitudinal tensile modulus of elasticity (MOE) was 30.88% larger for the samples treated with the low-molecular-weight PF resin than it was for the untreated samples. The av...

The high-temperature gas chromatographic (GC) separation of several semivolatile compounds is studied with a short metal capillary column packed with fibrous material, having a polydimethylsiloxane coating thereon. Taking advantage of the excellent heat-resistance of the fiber and also the combination of the surface-deactivated metal capillary, a temperature-programmed separation up to 450 degr...

In this communication, we will demonstrate that polymerization in a chiral solvent can affect the molecular weight distribution of the product by perturbing the balance of the P and M helical screw senses of the growing chains. Specifically, for the Wurtz-type synthesis of polymethylphenylsilane (PMPS) in either (R) or (S)-limonene, the weight-average molecular weight of the products (average M...

Heparin has been the most commonly used anticoagulant drug for nearly a century. The drug heparin is generally categorized into three forms according to its molecular weight: unfractionated (UF, average molecular weight 13 000), low molecular weight (average molecular weight 5000) and ultra-low-molecular-weight heparin (ULMWH, average molecular weight 2000). An overdose of heparin may lead to v...