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The production of bioethanol from lignocellulosic biomass could be considered as an appropriate and economic option to remove environmental disasters and improve energy security. In fact, lignocellulosic material is mainly composed of cellulose, hemicellulose and lignin. Lignin works as the adhering prevents the bioconversion of cellulose into sugars and ultimately to ethanol. To address the problem, various chemical, physical, physicochemical and biological methods have been suggested. Enjoying convenient operating conditions, production of non-hazardous wastes, and having no harmful side effects, make the biological methods a potentially proper option. Unfortunately, the biological methods are slower and less efficient in comparison with the other processes. In the present study, an attempt is made to resolve this problem in an enzymatic degradation of lignin of a rice straw sample. Several peroxidase enzymes were produced by a white rot fungus, and their effects on lignin removal from the biomass samples were investigated in shaking flasks. Lignin concentration and enzymes' activity were measured by the acetyl bromide-soluble lignin spectrophotometric method and optical density method using special reagents, respectively. The results revealed that the enzymatic treatment could remove at least 30% of the lignin content of the lignocellulosic biomass. To achieve the maximum activity of the enzymes, The chemical composition of the culturing medium was optimized for the concentration of important metal ions including Cu2+, Mn2+ and Zn2+ through Box Behnken response surface methodology. The enzymes' activity at the obtained optimal conditions increased four times for Manganese peroxidase, and lignin peroxidase.

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The aim of this paper is twofold. It first investigates the demand for international reserves using panel data for 32 developing countries during the period 1975 – 2004. To this end, an Error Correction Model (ECM) approach is employed to estimate the empirical model and then a capital asset pricing model (CAMP) is used to determine the composition of the foreign exchange reserves. A dummy variable is included in the model to consider the effect of changing exchange rate system on the demand and the composition of international reserves. The results show that there is a negative relationship between exchange rate flexibility and the demand for international reserves.

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Essential fatty acids (omega3/6) which are precursors of prostaglandins and leukotrienes and play an important rules in treatment of diseases. These fatty acids cannot be synthesized by human and should be obtained by nutritional dietary. Gamma linolenic acid (GLA) is one of the omega 6 fatty acids that is useful in cardiovascular and cancer diseases. Fungi especially zygomycetes are known as the best lipid producers containing essential fatty acids. The purpose of this research was using of several oil wastes as the renewable and cheap substrates to production of essential fatty acids by zygomycete fungi Mucor rouxii DSM1194. Five oil wastes were studied and the production of lipids, biomass, essential fatty acids like GLA, linoleate (omega6) and alpha linolenate (omega3) were determined. Since production of GLA was considerable, it was optimized by hierarchical experimental design, including a half fraction factorial and then design following by the response surface method (RSM). Yeast extract, ammonium sulphate and carbon source (oil wastes) were the significant factors on optimization of GLA production. Results showed after 72h growth of fungi in 28° C on R1 oil waste (obtained from restaurant), 56.4 mg/l GLA were produced which increased to 82.23 mg/l after optimization. The interaction of carbon and nitrogen sources was significant while yeast extract and ammonium sulphate didn`t have any interaction effects.

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Transmission-based teacher education programs have mostly dominated the field of teaching English as a foreign language. Considering the prominent position of critical pedagogical principles in prospective teachers’ perceptions of their professional roles and responsibilities, there is a need for detailed investigations of teacher education programs informed by the tenets of critical pedagogy in prospective teachers’ professional identity. There has been a paucity of research that addresses the impact of such programs on prospective teachers’ professional identity in an EFL context; therefore, this study intends to address the gap. This qualitative study was conducted to examine the role of a critical-informed teacher education program in influencing prospective EFL teachers’ professional identity construction. Participants were 19 prospective teachers whose process of professional identity construction were analysed through reflective journals, class discussions, and semi-structured interviews before and after the program. Results of the study revealed three major shifts in prospective teachers’ professional identity: “from a student’s voice to a teacher’s voice”, “from an uncritical attitude to developing agency”, “from a narrow view of ELT to a broad view”. To foster critical ideas in EFL prospective teachers, the study recommends the use of dialogic discussions and written reflective tasks in teacher education programs.