CRACKING CORROSION OF LOW CARBON STEEL IN ENVIRONMENT WITH A HIGH CONCENTRATION OF CO2 AND H2S

Cracking corrosion of API 5CT Grade L80 Type 1 low carbon steel has been studied in a in brine solutions with H2S 12.3 psia and CO2 9.4 psia. Testing was performed according to the methodology reference from the NACE TM0177, Bent-beam test method in solution B for stress corrosion cracking and sulfide stress corrosion cracking test and NACE TM0284, immersion test method in solution A for Hydrogen induced cracking test.The obtained results showed pitting and general corrosion at both temperatures of 24 oC and 82 oC. In case of stress corrosion cracking (SCC) testing at 82 °C, microscopy of the samples tested for 30 days developed pitting corrosion in the surface and cracking starting in the surface of the samples. The cracks, mostly found in the middle of the samples where the maximum bending occurred. General corrosion was also observed in the samples, with significant decrease in the dimensions of the samples after testing (due to general corrosion). However, in case of sulfide stress corrosion (SSC) and hydrogen induced cracking (HIC) tests at room temperature (24-25 oC), no cracking was observed on the sample.

Vitamin C inhibited FasL-induced apoptotic death of mouse dendritic cells through c-FLIP expression

Vitamin C (VitC) is a potent antioxidant and contributes as an apoptosis inhibitor by preventing death receptor-triggered caspase 8 activity. Fas ligand (FasL) induces the apoptotic cell death via activation of Fas signaling, which is dependent on the expression level of anti-apoptotic molecule c-FLIP (FADD-like IL-1beta-converting enzyme-inhibitory proteins). The present study addressed the effects of VitC on survival of dendritic cells (DCs), a regulator of innate and adaptive immunity. To this end, mouse bone marrow cells were isolated and cultured to attain bone marrow-derived DCs (BMDCs). The cells were treated with FasL in the presence or absence of VitC. Real time RT-PCR, Western blotting and FACS analysis were performed to determine different hallmarks of DC apoptosis. As a result, FasL treatment resulted in activation of caspase 8 and stimulation of cell membrane scrambling, the effects were supressed when VitC was present in the cell culture or the cells were transfected with FLIP siRNA. In conclusion, VitC prevented FasL-triggered DC apoptosis mediated through the expression of c-FLIP

Typical Values of the Nguyen Dynasty’s Decorative Art on Bronze Objects in Hue

In the general relationship of culture and art, the Nguyen lords and kings made many contributions to the shaping and development of Cochinchina, enhanced the country's position and influence with other countries in the region. The decorative art on bronze objects in the Nguyen Dynasty contains many cultural, historical and aesthetic values with multi-dimensional and multi-layered symbol. This has shown the synthesis of values, in which aesthetic value is one of the outstanding points. The decorative art on bronze objects in the Nguyen Dynasty take an important role in preserving and conserving national artistic and cultural values. Besides this, the expressive value on bronze and the emotiveness from the surface of the material also enhance the values of the decorative art. The Nguyen Dynasty’s decorative art on bronze objects in Hue has shown the richness of art and culture. Through the study we can see and feel the great ingenuity and creative spirit of the artisan classes. This is one of the factors affirming the position of the Nguyen dynasty's decorative art on bronze objects in the general of Vietnamese bronze art

INFLUENCE OF MONOETHYLENE GLYCOL ON CORROSION INHIBITOR OF WET GAS PIPELINE

In wet gas pipelines, monoethylene glycol (MEG) is widely used as a hydrate inhibitor, which can absorb free water and make decrease the corrosion rate of carbon steel pipeline. On the other hand, the presence of MEG affects on the solubility and diffusivity of CO2 in water. So, this paper presents a study of MEG inhibition properties in acid gas with CO2 content of 4 mol. %, an influence of MEG content in the brine water, pH and temperature on the corrosion rate of carbon steel by linear polarization resistance (LPR) and mass loss methods. The results show that the more MEG content increases, the more corrosion rate decreases. However, this effect is not significant unless the MEG content in the bulk liquid phase is higher than 70 wt. %.

Factors Affecting Youtube Acceptance For Student Learning Needs

This study was conducted to demonstrate the factors that influence Vietnamese students’ acceptance of YouTube for educational purposes. Qualitative and quantitative research methods are combined to test the research hypotheses. Research data was collected using quota sampling, with a sample size of 306 students studying at universities in Vietnam. Structural equation modeling (SEM) helps demonstrate that five factors positively affect the intention to use YouTube for student learning needs. These factors include performance expectancy, effort expectancy, hedonic motivation, social influence, and flexibility. Furthermore, research has demonstrated the positive impact of intentional use on the behavioral usage of YouTube for the educational requirements of Vietnamese students. The study provides a valuable reference for educational administrators and researchers

Optimization of L-asparaginase production from Escherichia coli using response surface methodology

Among the antitumor drugs, bacterial enzyme L-asparaginase has been employed as the most effective chemotherapeutic agent in pediatric oncotherapy especially for acute lymphoblastic leukemia. In previous study, the L-asparaginase from Erwinia chrysanthermy was expressed in Escherichia coli BL21(DE3). The recombinant L-asparaginase was produced from recombinant E.coli BL21(DE3) under different cultivation conditions (inducer concentration, inoculum concentration and KH2PO4 concentration). The optimized conditions by response surface methodology using face centered central composite design. The analysis of variance coupled with larger value of R2 (0.9) showed that the quadratic model used for the prediction was highly significant (p 0.05). Under the optimized conditions, the model produced L-asparaginase activity of 123.74 U/ml at 1.03 mM IPTG, 3% (v/v) inoculum and 0.5% (w/v) KH2PO4. Recombinant protein was purified by two step using gel filtration and DEAE chromatography. The purified L-asparaginase had a molecular mass of 37 kDa with specific activity of 462 U/mg and identified by MALDI-TOF mass spectrometry. Results of MALDI-TOF analysis confirmed that recombinant protein was L-asparaginase II. Recombinant L-asparaginase has antiproliferative activity with K562 cell line. In conclusion, this study has innovatively developed cultivation conditions for better production of recombinant L-asparaginase in shake flask culture

THE CONSUMER TRENDS OF SECONDHAND CLOTHING IN YOUNG PEOPLE – THE CASE OF THE GENERATION Z OF VIETNAM

In recent years, secondhand clothes have become a fashion trend that is enthusiastically supported by Vietnamese youth thanks to their fashionability and environmental friendliness. A series of second-hand shops, warehouses, and consignment events have sprung up in parallel with second-hand markets that have existed for many years, still attracting many visitors. In order to examine the trend of secondhand clothing consumption among young Vietnamese, the research team conducted this study. Through the results of the study, it can be seen that the main personal factors leading to the use of secondhand clothes by the survey subjects are spending savings and personal preferences. Most of the decisions to buy secondhand clothes are influenced by the uniqueness of the product and by friends and relatives. The most enabling aspect when using secondhand clothes is the product quality and the product's design, while the aspects that are the most concerns by both users and non-users of secondhand clothes are a matter of hygiene and health

Website Innovation Affects Student Satisfaction

University websites are more and more essential in communicating, exchanging information, providing educational services, and implementing marketing programs. Innovating the website is an important solution to improve the quality of educational services and attract students. This study was conducted to demonstrate the role of website innovation on student satisfaction. Research data were collected using quota sampling with 280 students studying at universities in Vietnam. Qualitative and quantitative research are used to test the research hypotheses. Applying structural equation modeling (SEM), the study shows that website innovation positively affects students’ perceived ease of use, perceived usefulness, and trust. Besides, perceived ease of use, perceived usefulness, and trust positively influence student satisfaction. This study has demonstrated that website innovation affects student satisfaction through the mediating role of perceived ease of use, perceived usefulness, and trust