Investigation of Carbon Footprints of Three Desalination Technologies: Reverse Osmosis (RO), Multi-Stage Flash Distillation (MSF) and Multi-Effect Distillation (MED)

Nowadays, the drinking water shortage is increasing, mainly due to rapid population growth, climate change, wasteful overuse of water, and pollution. Under the current circumstances, a quarter of the world's population will not have access to good quality drinking water. Thus, another solution must be adopted in areas with insufficient freshwater. One possible line is the desalination of seawater, one of the most practical solutions to solve the problem of drinking water shortage along the oil availability shore and continues to expand globally. Water produced may also be utilized for irrigation, reducing a region's reliance on imports, contributing to the local economy, and improving food supplies. However, this process is not a consequences-free procedure; it may cause several environmental and human health problems.The three most applied desalination technologies are reverse osmosis (RO), multi-stage flash distillation (MSF), and multi-effect distillation (MED). In this study, the emissions of greenhouse gases (GHGs) of drinking water produced from seawater using these three technologies with fossil and renewable energy sources were investigated based on two methods: life cycle assessment (LCA) using SimaPro life cycle analysis software and carbon footprints. As a result, RO technology has significantly lower CO2 emissions than thermal technologies. The RO combined renewable energy is the most environmentally friendly; provides outstanding benefits in terms of human health and ecosystem quality. This technology may still evolve in the future to produce longer-lasting, cheaper membranes, and the energy requirements of this process are lower with applying modern energy recovery systems

Expression of flagellin FLjB derived from Salmonella enterica serovar typhimurium in Escherichia coli BL21

Flagellin FljB composes flagellar antigen (H:1,2) of S. Typhimurium. This kind of antigen increases immunogenicity of any conjugated antigen upon administration. Thus, it is supposed to have an enormous potentiality for vaccine development against bacterial infections and cancer diseases. fljB gene (1515 nucleotides) coding for mature FljB was amplified by PCR from genomic DNA of S. Typhimurium and inserted into pET32a(+) for expression in E. coli BL21. The protein FljB was well expressed under the fusion form with Trx, S-tag at N terminal and hexa-histidine at C terminal, thus the recombinant protein was abbreviated to TrxFljB. Study on the impact of temperature on the gene expression showed that TrxFljB was synthesized at lower level at 37oC comparing to the levels at 22oC and 25oC. 13% of the protein synthesized at 37oC was inclusion body. Lower temperatures used during induction phase increased the solubility of the recombinant protein. About 97% of TrxFljB synthesized at 25oC was soluble. IPTG concentration had a strong effect on the growth of freshly transformed cells but did not affect on the growth of stored and re-cultivated cells. The increase of IPTG concentration resulted in the decrease of the growth of freshly transformed cells and the TrxFljB productivity. However, 0.05 mM IPTG concentration was found to gain the full TrxFljB expression. TrxFljB productivity declined during storage of cells at 4oC and re-cultivation. At optimal condition, volumetric productivity of TrxFljB was about 300 mg/ l broth.

Theoretical Framework on the Role of Knowledge Management for Students on Academic Performance

Knowledge management is a developing sector that has received lots of consideration and support from the community which is industrial. Knowledge management is a young academic field which has not been built up a systematized and unified framework. This paper reviews the role of knowledge management for students on academic performance by using the structural equation modeling. Through applying knowledge management in the study process can help students to gain better results. As a result, it can be expected to shed light on the relative importance of knowledge management on students’ academic performance. Keywords: Knowledge management, Academic performance, digital economy DOI: 10.7176/IKM/11-2-05 Publication date:March 31st 202

Entrepreneurship Education in Vietnamese Universities: Multi-Dimensional Approach From Economic Law and Human Rights

Entrepreneurial spirit and issues of digital division have linked to SDGs 4 and 8. In this study, the goals of 4.4 are strengthened with the aim of significantly increasing the quality and quantity of students with skills related to entrepreneurship, promoting employment rights and entrepreneurial spirit. The study is carried out based on previous studies (Lucas, et al., 2004; Ahmad, et al., 2015; Hussain, et al., 2010) to assess cognitive background; attitude; the impact of family, social and ethnic factors; content, types and methods of education and development direction of the law for entrepreneurship education. With a major slice from the perspective of economic law and human rights law, taking into account the division between ethnic minorities and majority people, under a multi-disciplinary approach, the study is conducted to provide initial proposals in the field of law, promoting the sustainable development of Vietnam in the coming time

Antibacterial activity of Piper betle extracts on Helicobacter pylori and identification of potential compounds

Helicobacter pylori is one of the most common infectious bacteria in the world that causes gastric diseases leading to cancer. The increase of multiple antibiotic resistance rates of H. pylori have been reported worldwide. Thus, development of novel drugs is urgently required. Piper betle has many therapeutic values in traditional medicine. In this study, therefore, we investigated antibacterial activity of P. betle extracts and their fractions against a H. pylori strain isolated in Vietnam. The agar disk diffusion assay showed inhibition zone of ethyl acetate extract and methanol extract from P. betle leaf that of were 46 mm and 32 mm in diameter, respectively. After fractionation of the ethyl acetate extract through silica gel column chromatography, two peaks, PD2 and PD3, out of 12 fractions showed the strongest antibacterial activity. PD2 was sub-fractionated further by re-chromatography on the silica gel column, and subfraction TK12 gave best resolution on LC-MS analysis. Finally, 4 potential compounds, quercetrin, calodenin B, vitexin and plicatipyrone, were identified in TK12 fraction.

In silico mining for alkaline enzymes from metagenomic dna data of gut microbes of the lower termite Coptotermes gestroi in Vietnam

The high alkaline proteases, lipases, cellulases and hemicellulases are important enzymes in research and industries. In this study, using the Alcapred software, the metagenomic DNA sequences of  the gut flora of Coptotermes gestroi were analyzed to identify the enzymes that were specifically adapted to alkaline condition. The results show that 737 of 943 ORFs (accounting for 72%) encoded proteases, 154 of 214 ORFs (holding 78%) encoded lipases and 338 of 575 ORFs (accounting for 59%) encoded cellulase and hemicelluase. All those enzymes were predicted to be alkaline enzymes. This study provide an overview picture of the alkaline enzyme groups of the gut flora of C. gestroi, and provide a good database for mining, isolation of the genes to produce recombinant enzymes

Development of Hybrid Organophilic Pervaporation and Distillation Method for Separation of Mixture Containing Heterogeneous Azeotropic

The study is motivated by the industrial separation problem in the fine chemical and pharmaceutical industry, that is isobutanol removal from process wastewater. There are several options for separating the isobutanolwater system. When separating on an industrial scale, it is essential that the most suitable alternative is implemented. The classical method of isobutanol-water separation is distillation. However, since the mixture forms a heteroazeotrope, only an azeotrope composition can be achieved with traditional distillation. Azeotropic distillation is a solution, the alternative is membrane separation, including pervaporation. The aim of this study is to investigate and optimize hybrid organophilic pervaporation and distillation processes for the separation of the isobutanol-water mixture. The examination is carried out in professional flowsheet simulator environment with user-added organophilic pervaporation membrane modules, phase separator and distillation column. Applying this new process, it is possible to obtain 99.9 weight% alcohol and water product from the initial 7 weight% isobutanol - 93 weight% water mixture

Life Cycle, PESTLE and Multi-Criteria Decision Analysis of Membrane Contactor-Based Nitrogen Recovery Process

Nitrogen is one of the most critical nutrients in the biosphere, and it is an essential nutrient for plant growth. Nitrogen exists in the atmosphere vastly as a gaseous form, but only reactive nitrogen is usable for plants. It is a valuable resource and worth recovering in the wastewater sector. The aim of this work was to prepare a comprehensive environmental analysis of a novel membrane contactor-based process, which is capable of highly efficient nitrogen removal from wastewater. Life cycle assessment (LCA), PESTLE and multi-criteria decision analysis (MCDA) were applied to evaluate the process. The EF 3.0 method, preferred by the European Commission, IMPACT World+, ReCiPe 2016 and IPCC 2021 GWP100 methods were used with six different energy resources—electricity high voltage, solar, nuclear, heat and power and wind energy. The functional unit of 1 m3 of water product was considered as output and “gate-to-gate” analysis was examined. The results of our study show that renewable energy resources cause a significantly lower environmental load than traditional energy resources. TOPSIS score was used to evaluate the alternatives in the case of MCDA. For the EU region, the most advantageous option was found to be wind energy onshore with a score of 0.76, and the following, nuclear, was 0.70