391 research outputs found
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
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
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
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
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
Radiation grafted natural fibres functionalized with alkalised amine for transesterification of cottonseed oil to biodiesel
Poly(glycidyl methacrylate) grafted Linum usitatissimum (flax) fibers functionalized with diethylamine (DEA) groups followed by alkalisation were prepared and used as a heterogeneous catalyst for production of biodiesel. Particularly, the new basic catalyst was used for transesterification of cottonseed oil using different molar ratios with methanol and various reaction temperatures. The gas chromatography analysis was used to confirm the conversion of the cottonseed oil to biodiesel. The transesterification reaction temperature affected the conversion percentage significantly. The highest conversion was obtained at 60 °C. In addition, the oil/methanol ratio in the reaction mixture of 1:33 resulted in the highest conversion ratio reaching about 97 %. These results suggest that the alkaline organic catalyst prepared in this study has a potential for application in biodiesel production
Constitutional Compliance Solution to Law Testing Rulings in the Constitutional Court
One of the current constitutional issues in Indonesia is the non-compliance of the decision to immediately follow up the decision of the Constitutional Court, which is final. This paper aims to analyze forms of non-compliance with the decision of the Constitutional Court and create a model that is expected to be a solution to the problem. This type of research is juridical normative by using secondary data processed by editing and systematization techniques. The results showed the form of non-compliance of the decision of the Constitutional Court by the addresat of the decision is manifested in 3 (three) forms, namely normative, praxis, and normative and praxis forms. There are three proposed state-regulation solutions, namely judicial deferral by limiting the time of action, re-affirmation of judicial restraint, collaborative action, and collective awareness between state institutions
Extensions of Weak PS-Rings
In this paper, we prove that, under mild conditions, if R is a right weak PS-ring, then so does the skew inverse power series ring R[[x−1;α,δ]], the skew generalized power series ring R[[S,ω]], and the differential inverse power series ring R[[x−1;δ]]
Sandwich structure polymer electrolyte membranes containing phosphotungstic acid immobilized electospun nanofibers
The advances in proton exchange membranes (PEM)s is critical for improving the performance of fuel cells [1]. Membranes compromising perfluorosulfonic acid polymers such as Nafion have been used extensively due to their desired conductivity and stability. However, these materials need to be saturated with water to obtain practical level of proton conductivity. There is a strong demand for the PEMs to work at lower relative humidity or under anhydrous conditions because the electrochemical reactions will be accelerated and water management of fuel cell will be simpler. Various designing strategies and advanced materials have been developed to mitigate for this issue without causing serious loss in proton conductivity or stability [2]. Among all, the introducing of inorganic proton conductors such as heteropoly acids have been considered widely. Generally, HPAs (such as phosphotungstic acid H3PW12O40, PWA) have a very strong Brønsted acidity approaching the superacid region (more acidic than Nafion) [3]. In this work, high level of PWA was self-anchored onto nylon electrospun nanofiberous sheet (Figure 1b). Sandwich structured proton conducting membranes were fabricate by assembling nanofibrous central layer with outer Nafion layers (Figure 1b). Since the PWA is attached to the polymer backbones, the risk of leaching out is minimized. Moreover, the significant synthetic versatility of the method helps to increase PWA immobilization level. As shown in the Figure 1c, proton conductivity of as high as 60 mS cm-1 at 30 °C was achieved which is comparable with Nafion 115. The durability of the proton conductivity of sandwiched membrane
- …