Grammar instruction presents a significant challenge in second language education. This challenge is particularly evident in teaching Persian grammar to non-native speakers. A crucial issue in the field of second language acquisition is understanding the developmental stages that learners go through and the underlying reasons. Processability Theory, a prominent framework, posits that second language acquisition follows a developmental Hierarchy: Learners acquire content words, function words, phrases, sentences, and subordinate clauses in a specific order. Given the complexity of Persian grammar, particularly conditional structures, this study aimed to investigate the acquisition sequence of these structures among non-native Persian learners from a Processability perspective. By analysing interviews with 120 learners at varying proficiency levels, we determined the order in which learners acquired different conditional constructions. The findings revealed a specific acquisition order: Learners typically mastered simpler conditional forms before progressing to more complex ones. Accordingly, a pedagogical model for teaching conditional structures was proposed, tailored to the specific challenges and developmental stages of non-native Persian learners. This model is grounded in the Processability Theory, ensuring a systematic and effective approach to instruction.

Jajarm bauxite mine as a largest known bauxite ore reserves with more than twenty million tons of diasporic bauxite, located in the north of Khorasan province, Iran. This bauxite mine cannot provide the suitable feed for at least twenty tears. Therefore, the possibility of using other bauxite deposits such as Shah-Bolaghi bauxite mine in Tehran province and Sorkh-cheshmeh mine in the north of Khorasan province was investigated. These studies were carried out based on the dissolution and sedimentation velocity of red mud. The results show that using these deposits separately is not applicable, because of low dissolution and/or low sedimentation velocity of red mud. The other parameters such as dissolution temperature, the amount of lime and Na2Oc must be carefully controlled to have the better results. Accordingly, a mixture of 50-50 Jajarm and Shah-Bolaghi bauxite ore has had the better performance with higher dissolution efficiency and also the lesser alumina amount in red mud.

Blends of linear low-density polyethylene (LLDPE)/poly(vinyl alcohol) (PVA) were prepared by conventional thermoplastic processing technique. The blends were mixed using a Haake rheometer at 150°C and 50 rpm for 10 min. The LLDPE and PVA were blended to give the following blend ratios (php): 90/10, 80/20, 60/40, 50/50 and 40/60. The effect of maleic acid via in situ cross-linking on Processability, component interaction, miscibility, thermal stability, tensile properties, and morphology of LLDPE/PVA blends was investigated in this research. The results indicated that the presence of maleic acid increases the equilibrium torque of LLDPE/PVA blends. This observation may be due to better compatibility and cross-linking between LLDPE and PVA. The formation of cross-linking was confirmed by Fourier transform infrared analysis and depression of melting points of PVA and LLDPE in the blends. The thermal stability and mechanical properties such as tensile strength, elongation-atbreak, and Young's modulus of the LLDPE/PVA blends also improved in the presence of maleic acid. Evidence for greater compatibility between LLDPE and PVA was confirmed by emergence of elongated fibrils extending over the surface of the PVA dispersed phases in the LLDPE matrix as revealed by scanning electron microscopy micrographs.

Melt Processability and thermal stability of blends of low density polyethylene and ethylene vinyl acetate copolymer modified with different dosages of phosphorylated cashew nut shell liquid (PCNSL) prepolymer have been studied using Brabender Plasticorder and thermogravimetric analysis, respectively. In all the blends having varying proportion of blend components, there was a progressive reduction in melt viscosity index with increase in dosage of PCNSL. The reduction in bandwidth of the Brabender torque profiles with increase in dosage of PCNSL from 0 to 10% indicated a decrease in melt elasticity of the blends. The reduction in indices of melt viscosity and melt elasticity of the blends in presence of PCNSL show the plasticizing effect of the additive and the consequent improvement in Processability. The improvement in Processability of the blends in presence of PCNSL was further evidenced by the decrease in power consumption during mixing, Modification of the blends with PCNSL resulted in significant improvement in thermal stability of the blends as evidenced by the progressive and significant increase in thermal stability index (T50) and shift in the thermograms to the high temperature region during thermogravimetric analysis.

The preparation and characterization of polyaniline/polystyrene (PANI-PS) composite are described. The polyaniline composite was synthesized by chemical polymerization of aniline in polystyrene emulsion matrix. The effects of dioctyl phthalate (DOP), N-methyl-pyrrolidone (NMP) and mineral oil as plasticizer on improving the Processability of PANI-PS composite are investigated by melt flow index (MFI) determination. It has been found that, among three tested plasticizers, DOP is more compatible with the composite. Using 35% (w/w) DOP, the MFI value of 0.093 g/10 min was recorded at 170°C. The DSC measurements of PANI-PS composite show a softening point at 106°C indicating that the obtained composite is melt processable above this temperature. Based on solubility studies, the composite is soluble in conventional organic solvents. The conductivity of about 0.013 S/cm is obtained for a free standing film of composite. Also the composite has shown excellent adhesion properties onto the steel plate. Cyclic voltammetric studies have revealed that the synthesized composite is electroactive, too.

Processability Theory (PT) is a second language acquisition (SLA) theory developed to explain developmental sequences in SLA as well as some other phenomena (Pienemann, 1998a). Processability has been a main concern in SLA research since 1990s. Following the agenda of Processability Theory and through analyzing the written performance of Iranian EFL learners’ writing performances, the present research studied the acquisition of “ 3 sg-s” and “ cancel aux-second or cancel inversion” across five proficiency levels, from elementary to advanced, and compared it with the stage-like development model of morpho-syntactic structures proposed by Pienemann (1998a). The study followed a descriptive method of research, and the data was collected from 350 participants in five different proficiency levels from elementary, pre-intermediate, intermediate, upper-intermediate and advanced. The participants were asked to provide samples of their written performance on different tasks including an introduction task, a habitual action task, a story retelling task, a picture description task, and a composition and communication task. The data in this research was analyzed both qualitatively, in order to recognize and classify the type and order of the morpho-syntactic structures, and quantitatively, by calculating means. The results of Kruskal-Wallis test revealed that both “ 3 sg-s” and “ cancel aux-second, ” as two morphosyntactic features, emerge very early in the language learners’ performance. Very similarly, the competence of the learner grows stronger in concern with these variables through the higher proficiency levels. These findings imply that PT is valid to a considerable extent for Iranian EFL learners, as well.

Pienemann (1998, 2015) put forward Processability Theory to enlighten why language learners follow definite developmental paths. The aim of the present study was to run a comparative investigation into the difficulty order of different grammatical structures for male and female Iranian EFL learners predicted by Processability Theory. 185 Iranian university students took part in this study. They received a Demographic Questionnaire and a Validated Researcher-Made Grammar Test designed based on the stages of Processability Theory. Item Response Theory (IRT) Rasch Modeling was used to analyze the collected data. Results pertained to the research questions revealed that the stages predicted by Processability Theory do not account for the Iranian male/female EFL learners. Another major finding emerged from the data was that the difficulty level of different grammatical structures presented by Pienneman in PT doesn’ t match the difficulty order obtained in this study by male/female EFL respondents. All things considered, results of the study provided a reliable counterevidence for the assumptions of the theory.