Sorption of vapors and gases by cellulose acetate films

Cellulose diacetate and triacetate films 6–55 µm thick with a total porosity of 0.8–2% were prepared by pouring a solution on an immobile surface and by calendering. Sorption of H₂S and CO₂ gases and acetone vapors on these films was investigated in static and dynamic conditions. It was shown that films 6–10 µm thick prepared by calendering should be used for purification of air from H₂S and CO₂ and films 15–20 µm thick prepared by pouring should be used for removal of acetone vapors.Engels Institute of Technology, Saratov State University. Translated from Khimicheskie Volokna, No. 6, pp. 44–46, November–December, 1995.     

Preparation of antireflection coatings from silicon dioxide on glass and quartz by the sol-gel method with oligoethers

Antireflection coatings with a low refractive index (1.18–1.23) have been prepared on silicate glass and optical quartz from mesoporous silicon dioxide synthesized by the sol-gel method in the presence of oligoethers. The optimum concentration of the oligoester in the sol is equal to 1.5–2.5 wt %. For the single-layer double-sided coating, the maximum transmission is equal to 99.0% for the silicate glass and 99.9% for quartz.     

Nutrition and blood lipid profile in adolescents during socioeconomic reforms in Russia: epidemiological study

Aim of study was to assess trends in lipid profile and nutrition of adolescent population in Novosibirsk during the social and economic reforms in Russia (1989-1999). Three cross-sectional studies of school aged 14-17 in 1989 (657), in 1994 (620) and in 1999 (626) were carried out. Total sample was 1903 (914 males and 989 females). Blood lipids, such as total cholesterol (TC0, high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG), were measured. Diet was estimated with the method of 24-hour dietary recall. During 10-year period mean serum TC decreased from 175 to 158 mg/dl in males and from 191 to 175 mg/dl in females (p < 0.001 for both genders). Females had significantly higher mean NC than did males at all surveys (p < 0.001)/Between 1989 and 1994 mean HDL-C levels decreased in boys both (p < 0.001), but in 1999 these levels were similar to 1989. During 1989-1994, TG levels significantly decreased, but between 1994 and 1999 mean TG levels increased in 1.5 times in both gender groups. Prevalence of high TC (> = 2000 mg/dl) significantly decreased from 17% to 6% in males and from 28% to 14% in females. Frequencies of low HDL-C (> = 40 mg/dl) also decreased in boys (from 28 to 8%) and girls (from 13 to 3%). Trends in diet showed similar changes and characterized by significant decreasing of total energy intakes (from 3021 to 2342 kcal in boys and from 2300 to 1644 kcal in girls) and of basic nutrient intakes (proteins? Fats? Carbohydrates). Negative trends in blood lipid profile and diet in adolescents during the unstable period of socioeconomic reforms in Russia indicate on serious changes in metabolic processes and need in large state economic programs to improve the situation.     

Rheological properties of spinning solutions for cellulose acetate ultrafiltration membranes

Addition of ethyl alcohol in the amount of 5 to 25 wt. % significantly reduces the viscosity of secondary cellulose acetate (SCA)—acetone—water spinning solutions. The effective viscosity of the spinning solutions decreases significantly when the shear stress changes. SCA membranes made from solutions with lower viscosity have higher permeability both for water and for cheese whey. The data obtained can be used to vary the performance properties of ultrafiltration membranes within wide limits. __________ Translated from Khimicheskie Volokna, No. 1, pp. 15–17, January–February, 2007.     

Ultrafiltration membranes made of secondary cellulose acetate modified with active carbon

It was hypothesized that active carbon will play the role of an inert filler and cause the formation of a more developed pore structure in membranes since pores are formed as a result of the counteraction of the forces of contraction and adhesion during phase separation in evaporation of the solvent. The carbon particles perturb the structure of the polymer network The porosity of the membranes also increases because the filler has a porous structure. Active carbon can be used to improve the performance properties of membranes. __________ Translated from Khimicheskie Volokna, No. 5, pp. 21–23, September–October, 2007.