The effects of solvent, temperature, time, weight percent of catalyst on the rate and mechanism of cyclization of natural rubber (NR) was studied in toluene and xylene solutions having tin tetra chloride catalyst (SnCl4). Iodometric titration show, with 8% SnCl4 (based on polymer weight) cyclization occurs, leaving 27.4% of the total unsaturation. Infrared spectra of c...

abstract introduction: due to environmental and human health concerns related to humic acid (ha), mainly leading to disinfection by-products creation, removal or reduction of this matters is a necessary for drinking water suppliers. based on resistive economy map road and move to self-sufficiency, it is necessary to produce our need in water treatment industry. one of the main consumed material...

background; water treatment sometimes needs a coagulation and flocculation process to remove suspended and colloidal materials. inorganic coagulants used create concerns about pollution of the environment and harmful effects on the human’s health. the studies carried out previously indicated the capability of an active coagulant agent extracted from descurainia sophia seed to remove turbidity o...

objective:  unaccustomed and intense eccentric exercise is a common cause of delayed-onset muscle soreness (doms). there are multiple remedies for the treatment of doms, but its clinical and laboratory pieces of evidence are scarce. currently, the treatments proposed for doms are numerous and include pharmaceuticals, herbal remedies, stretching, massage, nutritional supplements, and other alter...

a thin layer solar drying method was compared with a traditional method (sun drying) of paddy drying, with their effects on quality characteristics of two varieties of iranian rice (kamphiroozi and sazandegi) studied. solar drying process was conducted in a passive, mixed mode type solar dryer at about 50ºc for 90 minutes. in sun drying method this process took 8-10 hours at a mean temperature ...

soil productivity and plant growth are usually affected by biological activities of earthworms. the objective of this study was a comparative evaluation of earthworm abundances in 20-year-old plantations of alder, oak, maple and cypress with the adjacent natural mixed broad-leaved deciduous forest in the caspian region of iran. in this research one sample plot, each 1 ha; was selected in every ...

use of zinc and iron oxide are common in the desulfurization process from natural gas. in thisresearch, after determinations of the size and specifications through tem and xrd for each of the metaloxides, two different size ratios were used, 0.66 for zinc oxide and 0.142 for iron oxide. further, absorption of sulfur compounds in gas (hydrogen sulfide (h2s), carbonyl sulfide (cos), methyl mercap...

background: although natural disasters leave thousands of deaths and wounded, one of their most significant outcomes is empowering women as well as taking measures with special attention to women. this study aimed to analyze women’s cooperation and its affective factors in natural disasters and accidents. materials and methods: the study design is cross-sectional and descriptive. the study popu...

background & aim: myrtle (myrtus communis l.), is an important medicinal plant that is used for pharmacological uses and conservation of environments (for example preventing the soil erosion) regards to its specific condition habitat.experimental: in this research, phytochemical variations of the essential oils from different populations of myrtle collected from fars (saydan, cheshme-ali, a...

background: in iran, architectures are often unaware of the risk of radon inhalation and how to reduce radon levels. furthermore, radon considerations are not implemented in construction methods, construction materials and building utilization by regulatory authorities. materials and methods: in this study after reviewing the meteorological changes of ramsar over the past 50 years (1955-2005), ...