a new chemical compound is developed at petroleum university of technology to enhance therecovery of the free imbibition process and simultaneously hinder asphaltene precipitation. thecompound is tested on heavy oil samples from marun oil field, bangestan reservoir. the effects ofthe chemical compound on viscosity, hydrocarbon composition, and average molecular weight ofthe heavy oil are invest...

Control of copolymer composition and molecular weight distributions is important, since they partially govern material performance. This work uses a simple but robust approach to approximate predictive control of average composition and molecular weight during free radical copolymerization, based on detailed kinetics obtained by ACOMP (automatic continuous online monitoring of polymerization re...

microsatellite markers were used to identify informative markers associated with traits lattice shape of pod, belly shape in pod, pod length, pod width, grain number per pod, grain weight, grain weight/pod weight, grain length, grain width, pod number per plant, grain number per plant, pod weight per plant, grain weight per plant in peanut. thirteen ssr primer pairs amplified 80 alleles among 6...

Heparosan is an acidic polysaccharide natural product, which serves as the critical precursor in heparin biosynthesis and in the chemoenzymatic synthesis of bioengineered heparin. Heparosan is also the capsular polysaccharide of Escherichia coli K5 strain. The current study was focused on the examination of the fermentation of E. coli K5 with the goal of producing heparosan in high yield and vo...

Author for Correspondence: Ajaya Bhattarai, Department of Chemistry, Mahendra Morang Adrash Multiple Campus, Biratnagar, Tribhuvan University, Nepal. Email: [email protected]. Abstract: Precise measurements on the viscosity of aqueous solutions of sodium polystyrenesulphonate and in presence 0.1 N sodium chloride at 308.15 K were reported. The degree of substitution of sodium polystyrenesulphon...

in this article, a complete model for the mixed flow slurry reactor for polymerization of ethylene to high density polyethylene in the presence of ziegler-natta catalyst is presented. in addition to the effects of the multiple active sites, the effect of other important parameters such as the catalyst concentration, co-catalyst, hydrogen, monomer, impurities and pressure on the mass-average and...

Poly(ethylenimine) (PEI) samples of various molecular weights and pHs were used to transfect endothelial cells to achieve levels of gene expression for comparison. PEIs with nominal molecular weights of 600, 1200, 1800, 10,000, and 70,000 Da were examined at pHs of 5. 0, 6.0, 7.0, and 8.0, and the results were recorded in terms of transfection efficiencies at 24, 48, 68, 92, and 120 h post-tran...

the purpose of the present study was to investigate the effect of polyethylene glycol (peg) molecular weights (6000, 12000 and 20000) as solid dispersion (sd) carriers on the dissolution behavior of simvastatin. sds with various drug : carrier ratios were prepared by solvent method and evaluated for dissolution rate. differential scanning calorimetry (dsc), x-ray diffraction (xrd), infrared spe...

Matrix-assisted ultraviolet laser-desorption ionization time-of-flight mass spectrometry (UV-MALDI-TOF-MS) was applied to sulfated xylo-mannan fractions from Nothogenia fastigiata in order to determine their molecular weights and distribution profiles. The number-average molecular weight calculated from the spectra was similar to that determined by chemical end-group analysis for the lower mole...

The threshold surface porosity in the dormant spore of Bacillus cereus strain T was assessed by measuring passive permeabilities to a series of polydisperse polyethylene glycol samples which increased in average molecular size. The apparent exclusion threshold at diffusional equilibrium corresponded to a polymer of number-average molecular weight ( M(n)) = 150,000 and equivalent hydrodynamic ra...