Structural investigations of poly(ethylene terephthalate)- graft-polystyrene copolymer films

Structural investigations of poly(ethylene terephthalate)-graft-polystyrene (PET-g-PS) films prepared by radiation-induced grafting of styrene onto commercial poly- (ethylene terephthalate) (PET) films were carried out by FTIR, X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The variation in the degree of crystallinity and the thermal characteristics of PETfilms was correlated withthe amount of polystyrene grafted therein (i.e., the degree of grafting). The heat of melting was found to be a function of PET crystalline fraction in the grafted films. The grafting is found to take place by incorporation of amorphous polystyrene grafts in the entire noncrystalline (amorphous) region of the PET films and at the surface of the crystallites. This results in a decrease in the degree of crystallinity with the increase in the degree of grafting, attributed to the dilution of PET crystalline structure with the amorphous polystyrene, without almost any disruption in the inherent crystallinity

Gamma radiation-induced graft copolymerization of styrene onto poly(ethyleneTerephthalate) films

Gamma radiation-induced graft copolymerization of styrene onto poly(ethylene terephthalate) (PET) films was studied using simultaneous irradiation technique. The effects of grafting conditions on the degree of grafting were investigated. The grafting conditions include monomer concentration, irradiation dose, dose rate, and the type of solvent. Moreover, the effect of the addition of crosslinking agents [i.e., divinylbenzene (DVB) and triallyl cyanurate (TAC)] having various concentrations were also investigated. The degree of grafting was found to be greatly dependent on the grafting conditions. Of the three diluents employed, methylene chloride was found to drastically enhance the degree of grafting. The order of dependence of the initial rate of grafting on the monomer concentration was found to be 2.2. The grafted PET films were identified by FTIR spectroscopy and characterized by X-ray diffraction (XRD)

Water and charge transport models in proton exchange membranes: An overview

Recently, the significant role of water management in affecting the performance and durability of proton exchange membrane fuel cell (PEMFC) has been subjective to an intensive research to understand water transport phenomena which is marked by two processes: water adsorption and water diffusion. Various mathematical models have been developed to address both processes on a different basis. This article briefly reviews various water transport models in a comparative manner to have a better understanding on the role of water hydration with respect to membrane structure and transport mechanism, in affecting the proton transport in the membranes. A discussion on the validity and reliability of the models for describing the water management is also presented. The limitations that are required to be overcome to design new materials meeting the new trends of membranes development for fuel cell are also highlighted

Optimization of biodiesel production from waste cooking oil using ion exchange resins

Waste cooking oil is a potential alternative of refined vegetable oil for biodiesel production due to its low cost and elimination of its disposal problem. The concentration of free fatty acids (FFAs) in WCO dictates the type of chemical treatment required for biodiesel production: a single esterification reaction is considered at high content of FFAs, whereas, a combination of estrification and transestrification reaction is used at moderate content of FFAs. In this study, optimization of esterification process of FFAs in artificially acidified soybean oil with oleic acid combined with methanol as an agent and ion exchange resin as a heterogeneous catalyst was carried out. The optimization process was performed by means of Matlab software based on a kinetic model available in the literature. Conversion of acidified oil was determined as an objective function in correlation with reaction variables i.e., temperature and catalyst weight. It is found that the maximum conversion of the free acids is 95.95% which is achievable at 4.48 g catalyst loading and reaction temperature of 120°C

Inventory of Associated Marine Macro Algae Species to Rissoides Desmaresti (Crustacea - Stomatopoda), with screening of Bioactivity of shell extract

Background: Shrimp, Rissoides desmaresti, making a healthy choice for human consumption. Objective: This study aimed to isolate, and identify some natural bioactive marine products from its shell extract, as well as to investigate the biological activity of the seashell extract and the degree of its influence on various microbiological species and laryngeal cancer,, as well as to discover the distribution and relationship between it and marine algae, as the marine food chain. Materials and methods: Squills were gathered, and the varieties of marine algae connected with the organism in the maritime environment were tallied, since they are a major contributor in the marine environment's productivity. Several biologically active marine natural components were extracted, separated, and identified from the organism under research. Results: The findings revealed a seasonal variation in the percentage of marine algae present, which was reflected on diversity in the environment from one season to the next, and indicated the magnitude of the effect of seasonal change on productivity, food availability, and environmental yield. Antimicrobial activity of Rissoides desmaresti shell extract revealed significant differences between groups treated with shell extract (1.5, 2.5, and 5 mg/mL) in comparison with the control group. In addition, the viability of the Hep -2 cell line after treatment with Rissoides desmaresti shell extract was assessed and microscopic examination revealed a significant difference between the shell extract-treated groups and the control group. Depending on the dosage or concentration, cell viability decreased in a dose dependent way. The shell extract suppressed the growth of cancer cell line of larynx. Conclusion: The current study revealed that there was seasonal variation in the percentage of marine algae present, which is reflected in the observed species numbers of marine macro algae in the environment of the organism under study and had an impact on marine productivity, food availability, and eco-physiology of Rissoides desmaresti. Shell extract can be employed as an antibacterial, antifungal, and anticancer agent because of several natural bioactive marine compounds from Rissoides desmaresti shell extract

Preparation of proton exchange membrane by radiation-induced grafting method : Grafting of styrene onto poly(ethylene tetrafluoroethylene) copolymer films

Radiation induced grafting of styrene onto poly(ethylene-tetrafluoroethylene) (ETFE) copolymer film was carried out to prepare graft copolymer (ETFE-g-polystyrene) that can host sulfonic acid groups and form proton exchange membrane for polymer electrolyte fuel cell (PEFC). The effect of monomer concentration and type of solvent on the degree of grafting was investigated. The formation of graft copolymer film was confirmed by FTIR spectrum analysis

Extraction, Isolation and Identification of Some Natural Bioactive Marine Products from Squilla mantis (Stomatopoda-Squillidae) with Special Reference to Seasonal Variation of Marine Algae diversity

Background: Marine algae important in food chain, productivity and marine ecosystem, Also Squilla mantis is healthy human food. Aim of the work: To identify some biologically active natural marine products, and screening its bioactivity, as well as discover the seasonal variation diversity of associated marine algae, for its role in the marine food chain. Materials and methods: The squills were collected and marine macroalgae associated with it. Also, some biologically active marine natural products were extracted and identified from shell extract to examine its effect on some microbs and laryngeal cancer. Results: The results showed a seasonal variation in diversity of marine algae, which indicated the effect of seasonal change food availability and environmental yield. The results of antimicrobial activity of Squilla mantis shell extract indicated an important effect differences between the groups treated with shell extract (1.5, 2.5, and 5 mg/mL) compared to the control . Also, evaluation of viability of Hep-2 cell line post treatment with shell extract of Squilla mantis using sufranin uptake assay as (MTT) uptake and microscopic examination indicated a significant difference between the groups treated with shell extract compared to the control group. Cell viability decreased depending on dose or concentration. The shell extract inhibited the proliferation of a larynx cancer cell line in a dose dependent manner. Conclusion: The present study showed that, there are seasonal variation in marine algae diversity , which affect on productivity and food availability. Also, there are importance natural bioactive marine products from Squilla mantis shell extract

Studi Kritis Mengenai Kewenangan Dewan Kehormatan Penyelenggara Pemilu dalam Mengawal Electoral Integrity di Indonesia

Honorary Council Election (DKPP) is considered very progressive because in less than two years from its inauguration, it has solved around 127 cases. However, there are several decisions made by DKPP which are controversial because they make decisions and give sanctions to not only violations of ethical codes,  but also administrative sectors and conflicts related to general elections. The problems of this research are: first, what are the limits of DKPP’s authority in investigating and making decisions on ethical code violation during general election? Second, how is the relationship pattern among KPU (Election Supervisory Committee), Bawaslu (Election Watchdog), and DKPP which is based on electoral integrity in conducting general election? This research employed statute and conceptual approach as well as qualitative analysis. The findings show that: first, the limits of DKPP’s authority have been governed in the Constitution of Elections. DKPP only has authority to investigate and make decisions on the notions of ethical code violations which are done by election committee. Second, the pattern of the relationship among election committees in Indonesia has actually adopted the electoral integrity principles, but it will be better if DKPP, in doing its duties, does not overlap with the authority of other agencies or institutions so that they can work professionally

The preparation and characterization of chitosan/poly (vinyl alcohol) blended films : mechanical, thermal and surface investigations

In this study, blends of chitosan (CS) and polyvinyl alcohol (PVA) (CS/PVA) having various proportions were prepared and characterized by universal mechanical tester, the differential scanning calorimetry (DSC) and contact angle measurements. Studying the mechanical properties of the films showed that blending improved the tensile strength, which increased with increasing PVA content up to 40% while the elongation% at break of the blends was decreased compared to that of the pure components. The obtained results of DSC suggested that some interaction between chitosan and PVA mostly took place. Static water contact angle measurements showed an improvement in the wettability of the obtained films