mohammad taherzadeh

The use of starch in the future will face limitations due to food competition in the paper industry. Therefore, in this research, soda lignin was chemically modified using the amination method to extend its reactivity and improve water solubility. Sizing solutions were prepared using both unmodified and aminated lignin, as well as a combination of starch and lignin in a 25:75 ratio. The surface, barrier, and mechanical properties of the sized testliner papers were measured using the aforementioned sizing solutions. SEM images show that both unmodified and aminated lignin almost completely fill the voids and spaces between the fibers, creating a relatively uniform and homogenous sizing layer on the paper surface. The roughness values increased for the sized papers using both unmodified and aminated lignin. Applying a sizing layer with unmodified lignin reduced the air resistance of the paper, while papers treated with aminated lignin showed a slight increase in air resistance, though not as high as those sized with pure starch. Contact angle evaluation confirmed the positive effect of chemical modification through amination on the hydrophobicity rate of the paper. Surface sizing with aminated soda lignin, even without starch combination, resulted in increased stiffness, burst index, and Ring Crush Test (RCT) compared to the control papers.

From the point of view of Iranian medicine, each person has a unique temperament and two people can never be considered similar despite their appearance. Temperament is affected by three physiological, anthropometric and psychological factors. One of the important indicators of mental health in the field of psychology is self-esteem. The relationship between psychological variables and temperament is among the gaps that need more research. Therefore, the present study investigated the relationship between self-esteem and temperament in young non-athletes.

This research was a cross-sectional-analytical method that investigated the relationship between two temperaments (hot and cold) and self-esteem in young non-athletic male students in the fall season of 2018. After obtaining written informed consent from the applicants present in the research, the sample size was determined in the warm temperament group of 94 people and the cold temperament group of 93 people. Temperament classification of the subjects was done through the temperament diagnosis questionnaire (Mojahedi 2014) based on the type of temperament. Also, the self-esteem level of the subjects was evaluated with the Rosenberg Self-Esteem Scale (RSE). Due to the non-normality of the data, the differences between the groups were analyzed with the U-Man-Whitney test in the SPSS version 21 software environment.

Based on the obtained results, there are significant differences between the warm and cold temperament groups in the sub-components of self-esteem, self-worth in the cold-tempered groups with an average rank of 79.60 and warm-tempered groups with an average rank of 100.58 (P = 0.006). And the feeling of satisfaction was seen in the cold-tempered groups with an average rating of 77.23 and warm-tempered with an average rating of 103.23 (P = 0.001), so that the self-worth and satisfaction indicators in The warm-tempered group had the highest rating compared to the cold-tempered group.

The results were such that warm-tempered people had significantly more self-worth and satisfaction as components of self-esteem than cold-tempered people. In general, the self-esteem index as one of the variables of psychological sciences was higher in warm-tempered people.

The production of a coating agent based on the extracted lignin from black liquor of bagasse soda pulping was investigated. The crude lignin was modified via sulfomethylation method to increase its solubility. Both unmodified and sulfomethylated lignins were applied on the testliner papers with and without starch and physical, surface and mechanical properties of the coated testliners were evaluated. The viscosity of coated solution containing 100 percent of crude lignin was very low and similar as that of water. Addition of starch to coating solution resulted in increasing of the viscosity of formulation. Evaluation of hydrophobicity of coated testliners showed that compared to papers treated with unmodified lignin and starch, the papers treated with sulfomethylated lignin had significantly lower water absorption, wetting rate, absorption rate of water droplet, which resulted in hydrophobicity of papers. Colorimetric analyses showed a decrease in lightness (L*) of the coated testliners with only unmodified lignin compared with untreated control ones. In contrast, the lightness of testliners coated with sulfomethylated lignin was significantly improved and was almost as high as control samples and samples, which coated by the starch solution without lignins. Air permeability of the coated testliners with only lignin was significantly lower than that of lignin-starch coated samples. The results also showed that the tensile indices of samples coated with unmodified and modified lignins were significantly higher than that of control ones. The tensile index of testliners coated with starch-lignins solutions was almost near to that of samples treated with only starch solution.

Fossil fuels are the main sources of water, soil, and air pollution that threaten human life and other organisms on Earth. Nowadays, the climate change and pollution are critical issues; however, many countries still use polluting fossil fuels. Therefore, finding alternative and clean fuels is a concern for many environmental activists and scientists. One of these alternative fuels is ethanol, which ignites cleaner due to its higher hydroxyl groups and lack of sulfur and nitrogen in its formula. Ethanol can be produced both chemically and biologically. Till now, four generations of bioethanol have been introduced. In the second generation, lignocellulosic materials are used as the main source for bioethanol production. These materials are frequently found in plant biomasses and agricultural residues, which are inexpensive and environmentally sustainable. Therefore, it is of importance to improve the production process and find novel techniques that increase final yields and process efficacy. In this study, the structural properties of lignocellulosic materials, pretreatment techniques, the second-generation bioethanol production process, and the effective bacterial and fungal strains in this procedure are investigated.

This review study is a narrative review in which a logical search approach was selected. For data analysis, a comparative approach between the different methods was expressed in each section.

Among four bioethanol generations, the second generation has received remarkable attention due to its non-competition with human food and its industrial potential rather than other generations. Therefore, it is of particular significance to improve the production process of bioethanol second generation. A deep understanding of lignocellulosic components, pretreatment methods optimization, and increasing hydrolysis and fermentation processes efficiency make bioethanol production industrially possible and cost-effective.

However, despite extensive studies to select the most suitable microorganisms during the fermentation stage, Saccharomyces cerevisiae and Zymomonas mobilis are still at the forefront of studies.

Toxic compounds and inhibitors in lignocellulosic hydrolysates such as acetic acid and phenolic compounds are the major challenge for biochemical conversion of lignocellulosic materials into biofuels like bioethanol. In this study, the performance of four filamentous fungi Rhizopus oryzae, Mucor indicus, Neurospora intermedia and Aspergilus oryzae on the fungal biomass production, sugar and acetic acid consumption as well as ethanol production was investigated in synthetic mediums containing 0, 3, 5 and 7 g/L acetic acid. The fungal biomass obtained after 48 and 72 hours cultivation showed that the rate of the fungi growth and lag phase decreased and increased by acetic acid addition into the medium, respectively. The inhibitory effect of acetic acid on M. indicus growth was higher than those of other fungi, i.e., its biomass production decreased significantly at higher concentration of acetic acid (5 g/L), while A. oryzae showed pretty good tolerance to acetic acid. The results indicated that the effect of acetic acid on the fungal biomass and ethanol production was dependent on acetic acid concentration and the fungus type which can affect positively and/or negatively on the fermentation. The ethanol concentration from A. oryzae and R. oryzae cultivation in the medium containing acetic acid was decreased and increased, respectively. According to the fermentation results, the medium containing 7 g/L acetic acid was enough to stop the fungi growth and ethanol production.