Islamic Azad University, Buin-Zahra

Abstract This study investigates the synthesis and characterization of crosslinked poly(Bis-GMA) with cellulose using a chemical modification approach. The preparation involves three key steps: polymerization of bisphenol A glycidyl methacrylate (Bis-GMA), chlorination of poly(Bis-GMA), and crosslinking with cellulose. The resulting materials were characterized using CHN analysis, FT-IR, TGA-DTA, and mechanical testing. CHN analysis revealed changes in elemental composition due to chlorination and cellulose incorporation. At the same time, FT-IR confirmed successful chemical modifications, with the formation of new functional groups such as N-H and C-O bonds. TGA-DTA analysis indicated a decrease in thermal stability after crosslinking, with crosslinked poly(Bis-GMA) with cellulose decomposing at a lower temperature than Bis-GMA. Mechanical testing showed enhanced properties in the crosslinked material, with improved flexural strength, flexural modulus, diametral tensile strength, and compressive strength, likely due to the reinforcing effect of cellulose. Water adsorption studies highlighted the hydrophilic nature of cellulose, leading to increased water uptake in the crosslinked material. These findings suggest that cellulose-crosslinked poly(bis-GMA) offers improved mechanical properties and could be a promising material for applications in dental composites, biomedical coatings, and other polymer-based systems, though further modifications may be necessary to address water stability issues.

In this, a three-component reaction for the preparation of novel tetrazolo[1,5-a]pyrimidine-6-carboxamide derivatives from N,N′-(sulfonylbis(1,4-phenylene))bis(3-oxobutanamide), aldehydes and 1H-tetrazol-5-amine is reported. The application of Fe3O4@SiO2-(PP)(HSO4)2 (A) as a catalyst afforded the desired products (a1–a18) in high yields in DMF as solvent as well as under solvent-free conditions.

Physical and visual elements that help people find their way around an environment are called visual cues (VCs). The current study aims to evaluate adults' wayfinding abilities (navigation, orientation, spatial anxiety, and distance estimation) and VC (navigational color coding) preferences in terms of color and position; additionally, investigates their differences in adults' life span phases (young adults, early middle-aged adults, and late middle-aged adults). Wayfinding in complex environments such as healthcare centers has been challenging for most people. Although VCs are being used increasingly to facilitate wayfinding, considering people's preferences regarding VCs, especially navigational color coding, are neglected. Obtained data from a survey of 375 healthcare center visitors with textual and photo questionnaires were analyzed by descriptive statics and one-way analysis of variance. Young adults preferred VCs with "mixed colors and positioned in the middle of the floor," early middle-aged adults preferred "warm color VCs in the middle of the wall," and late middle-aged adults preferred "warm color VCs at the bottom of the wall." Additionally, the results demonstrated that with aging, navigation and distance estimation abilities deteriorate, and spatial anxiety increases. The outcomes of the present study increase our knowledge regarding the impact of adults' life span phases on their wayfinding abilities and VC preferences and offer suggestions for architects and healthcare center stakeholders to provide environments that improve adults' wayfinding.

In transient analysis (TA), the processing time (PT) and prediction accuracy (PA) are the most significant indices be influenced the decision-making of grid operators to conduct timely-accurate corrective actions. In fact, achieving low PT and high PA (high-performance TA) necessitates designing the comprehensive feature selection scheme to select optimal transient point features (OTPFs). Hence, the partial-injective trilateral hybrid (filter-wrapper) scheme called PITHS is introduced in this paper. First, the transient dataset in the form of multivariate time series is constructed by an integrated programming platform. Next, based on PITHS, the first univariate trajectory feature (UTF1) is entered into the nested trilateral filter phase (NTFP) equipped with intertwined triple criteria of information theory for selecting filter-OTPFs of UTF1 (f-1OTPFs). Then, f-1OTPFs are fed to the nested trilateral wrapper phase (NTWP) for selecting filter-wrapper-1OTPFs (fw-1OTPFs). The NTWP is including the hyperplane-based predictive approach accompanied by the triple kernel. After conducting NTWP, fw-1OTPFs are considered as the first ultimate optimal point features (1UOPFs). Next, survived fw-1OTPFs injected into the subsequent trajectory (UTF2), and the neo-formed trajectory (fw-1OTPFs plus UTF2) drives a new round of NTFP and NTWP for finding fw-2OTPFs (2UOPFs). By conducting this procedure on the last neo-formed trajectory (the fw-k-1OTPFs+UTFk), the fw-kOTPFs are obtained (kUOPFs). Finally, the 1:kUOPFs set is tested to verify their efficacy for TA based on the cross-validation technique. The obtained results show that the proposed framework has a prediction accuracy of 98.75 % and a processing time of 152.591 milliseconds for TA.

A novel complex has been prepared using the (E)-4-nitro-N-(pyridin-2-ylmethylidene)aniline bidentate Schiff base ligand and PtCl2, namely, dichlorido[(E)-4-nitro-N-(pyridin-2-ylmethylidene)aniline-κ2N,N']platinum(II) acetonitrile hemisolvate, [PtCl2(C12H9N3O2)]·0.5CH3CN, 1. According to the X-ray measurements of the crystal structure, the PtII ion adopts a PtCl2N2 square-planar coordination. The coordination of the Schiff base ligand to the PtII ion occurs in a cyclic bidentate fashion, as a result of which a five-membered metallacycle is formed. Furthermore, in the structure of 1, the neutral molecules form a one-dimensional chain structure through C-H...Cl and C-H...O hydrogen bonds. The characterization of the complex was performed via single-crystal X-ray diffraction, IR spectroscopy and elemental analysis, and the antioxidant activity of the complex was evaluated using spectrophotometry by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method.

A catalytic route to carbamothioate derivatives through a reaction involving isocyanides, elemental sulfur, and aryl iodides has been developed. The reaction scope has been examined using a range of isocyanides and aryl iodides. The reactions involve two consecutive C–S bond formations. Control experiment revealed that the reaction proceeds through an iminium species.

The paradigm shift from testing the outcome to assessing the learning of process shines a light on the alternative assessment approaches, among which portfolio-assessment has sparked researchers’ interest in writing instruction. This study aimed at investigating the effect of portfolio-assessment on Iranian EFL students’ writing achievement through the process-centered approach to writing. To this end, fifty-three sophomores, studying English translation at Islamic Azad University, Tehran Science and Research Branch, were chosen as the participants of this study. The researchers randomly divided them into two groups--an experimental and control. The experimental group received an instruction based on the four stages of the writing process--brainstorming, outlining, drafting, and editing--and underwent the portfolio-assessment. For ten weeks, the participants of the experimental group practiced reflecting on their writing through formative self-check, peer-review, and teacher-feedback on each of the stages written as homework assignments. The revised paragraphs were regarded as the final portfolio. The control group, however, received a product-based writing instruction, to which portfolio-assessment, individualized-feedback, and reflection did not adhere. The results of the quantitative data analysis showed that the students in the experimental group performed better than the students in the control group in their writing achievement. The qualitative findings also revealed the students’ positive perception toward the portfolio-assessment on the writing process. The results suggest some pedagogical implications for EFL writing instruction and assessment.

A novel synthesis of styrene derivatives through decaroxylative olefination of potassium benzoates with alkynes using Pd2dba3/CuBr as catalyst system has been developed. The protocol proceeded smoothly and in most cases Z-alkene was the main product. Electron-rich potassium benzoates reacted more efficiently than those of electron-deficient substrates. Heteroaromatic and electron-deficient aryl alkynes were not consistent with this transformation.

International entrepreneurship (IE) is fundamentally captured in the identification and exploitation of opportunities for international exchange. Yet little is known about the methods used by entrepreneurs for opportunity recognition. Previous work on IE emphasizes the importance of social networks for identifying opportunities in foreign markets. While business network and institutional network are less studied in previous studies, this paper aims to examine the effect of social, business, and institutional network on international opportunity recognition with the moderating role of entrepreneurial orientation. By applying network based theory to the analysis of 150 Iranians SMEs, the result indicates that; social network, business network, and institutional network positively affect international opportunities recognition. Furthermore the results show that entrepreneurial orientation moderated the effect of business, and institutional network on international opportunity recognition. While the moderating role of entrepreneurial orientation in the effect of social network on international opportunity recognition, is not supported.