nowdays, production of high quality engine oils is one of the worries of our country’s engine oil industry. in this study, the behavior of four commercial polymers used in nation motor oil industry in obtaining the best viscosity index improver was investigated. in this regard, viscometric behavior, shear stability and polymers’ performance for engine cranking were compared at low temperature. ...

The 70SiO2-15TiO2-15ZrO2 membrane was prepared by a sol-gel procedure. The corrosion behavior of microporous toplayers along with the membrane characterization in terms of pore size, surface area, pore volume and weight loss is described. The final ceramic membrane with a thickness of 400 nm and uniform surface was obtained. This membrane confirmed the fine microporous characteristic with mean ...

A PVC-based membrane containing cerium phosphate was developed. Unlike the cerium phosphate itself that acts as a cation exchanger, the membrane exhibited anion-exchange properties. Therefore, the utility of this compound as a sensory element for detection of molybdate ions was pursued. The response of molybdate selective electrode based on this membrane was perfectly linear in the concentr...

Solid alkaline fuel cell is employed by polymer anion exchange membrane (AEM) that is permeable to hydroxide ion. A number of polymers have been proposed for AEM which include polysulfone (PSF), poly (phenylene oxide) (PPO), and poly (ether ether ketone) (PEEK). The purpose of this paper was to conduct a critical review on the development of PEEK polymer as AEM, particu...

background: spindle trees (euonymus japonica thunb.) growing in an industrial complex area containing pollutants is chronically injured thus need to build up their resistance. antioxidant enzymes and cell membrane stability have been widely used to differentiate stress tolerance. materials and methods: leaves of spindle trees from a clean control area (kijang) and an industrial area (onsan) whe...

The U,S. Army Construction Engineering Research Laboratories (CERL) has been investigating the development of a test methodology for evaluating the service life of roofing membrane materials. As pat of this effort, CERL conducted a study to investigate the applicability of strain energy (a mechanical test) and Fourier transform infrared (FTIR) spectroscopy (a chemicat analysis) as methods for c...

soil and water salinity are the main agricultural problems in arid and semi arid areas in the world and iran. in order to investigate salinity tolerance of kochia, two experiments were conducted in a completely randomized design with four replications, seven levels of salinity (0, 10, 20, 30, 40, 50 and 60 ds m-1) and two growth stages (planting and early seedling) with gradually salinity appli...

in order to investigate the effects of drought stress and nitrogen fertilizer on photosynthesis rate and some physiological characteristics in two barley cultivars, a pot experiment was conducted using a randomized complete block design as a factorial experiment with three factors including water stress, nitrogen fertilizer and barley cultivars in three replications. irrigation treatments condu...