Effect of Rare Earth on M7C3 Eutectic Carbide in 13% Chromium Alloy Cast Iron

The crystallization process of hypoeutectic white cast iron consists of the first secreted austenite branch after the reaction of the austenite -carbide crystal is formed, and the phase crystal fills in the middle of the austenite branches. If the austenite branches are small and smooth, the crystals carbide are fine. The cast iron with 13% chromium which has 3 – 3.2% carbon, have the carbide crystalline as M7C3. The elements in rare earth have a strong affinity for oxygen and sulfur to produce rare earth oxides. These rare earth oxides can create heterogeneous germ center for austenite phases and smooth down these phases. The effect of rare earth on the M7C3 and crystals of 13% chrome white iron has been elucidated. Along with the increase of rare earth content, the microstructure of M7C3 with fine finely graded, more uniformly distributed, dispersed throughout the sample surface. When the carbide is fine and dispersion, will contribute to improving the properties of cast iron especially the impact strength as well as the abrasion resistance of the alloy. The research results show that in the presence of rare earth, rare earth elements created with oxygen and form La2O3 and Ce2O3 as the nucleation for the solidification process and create the small fineness of phases. The orientation of the crystal structure of these oxides is similar to the crystal structure orientation of Fe-γ phase. Finding and proving the oxides of rare earth has crystal structure with phase γ which will be small smooth exogenous minds that the microstructure has a smooth, small size

Adsorption of ciprofloxacin using composite Film from PVA, agarose and maltodextrin

Rintangan antibiotik ialah salah satu masalah yang paling membimbangkan hari ini. Oleh itu, membran komposit telah digunakan secara meluas untuk penyingkiran antibiotik daripada air. Filem PVA/Agarosa/Maltodekstrin telah disintesis dengan tuangan dengan pelbagai nisbah komponen. Ia dinilai untuk ciri melalui kelembapan, keterlarutan, pengembangan dan keputusan BET. Keputusan menunjukkan bahawa filem PVA/Agarosa/Maltodekstrin mempamerkan daya maju terbaik dalam persekitaran akuatik melalui keterlarutan rendah (68.88% ± 0.03), bengkak tinggi (431.77% ± 5.89) dan isi padu liang (0.034969 cm³/g). Kapasiti penjerapan PVA/Agarosa/Maltodekstrin telah diuji untuk beberapa antibiotik seperti Ciprofloksacin, Tetracycline, Oxy-Tetracycline dan Chloramphenicol. Keputusan menunjukkan bahawa Ciprofloksacin telah dikeluarkan oleh filem PVA/Agarosa/Maltodekstrin lebih baik daripada antibiotik lain. Penjerapan antibiotik tertinggi diperoleh pada 20 minit, suhu 30 °C, dos 2 g/L, pH 6 dan kepekatan antibiotik 40 mg/L. Penjerapan Ciprofloksacin telah diramalkan melalui model kinetik dan isoterma penjerapan. Keserasian kinetik Pseudo First Order dan isoterma Dubinin-Radushkevich telah menunjukkan bahawa penjerapan berlaku mengikut mekanisme penjerapan fizikal dengan interaksi elektrostatik pada permukaan bahan. Kapasiti penjerapan maksimum direkodkan pada 4.48 mg/g berdasarkan isoterma Dubinin-Radushkevich

MULTI-PIXEL PHOTON COUNTER FOR OPERATING A TABLETOP COSMIC RAY DETECTOR UNDER LOOSELY CONTROLLED CONDITIONS

The multi-pixel photon counter (MPPC) has recently emerged as a great type of silicon photomultiplier to replace or compensate for conventional vacuum-based photomultiplier tubes. An MPPC provides many advantageous features, such as high electrical gain, outstanding photon detection efficiency, fast timing response, immunity to magnetic fields, low-voltage operation, compactness, portability, and cost-effectiveness. This article examines the electrical and optical characteristics of an MPPC under loosely controlled environmental conditions. We also report a measurement of the light yield captured by the MPPC when a cosmic ray passes through the plastic scintillator, demonstrating that such a setup is suitable as a simple, cost-effective tabletop cosmic ray detector for educational and research purposes

Integrating of PLS-SEM and the Importance Performance Matrix Analysis to Exploring the Role of Provincial Competitiveness Index to Growth

Provincial competitiveness was one of the engines of growth under the institutional theory. The Vietnam Provincial Competitiveness Index (PCI) has been surveyed since 2005 to reflect the perceptions of local business environments, categorized into 10 sub-indices with 128 indicators. The current PCI has challenged the governance due to its broad construction. This study aimed to reconstruct the indicators in each PCI sub-index to be more specific for improving governance. The paper further explored the importance-of performance of both the PCI sub-index and its indicators to the provincial growth in Vietnam. Secondary data of 63 provinces during the period of 2017-2020 have been used with the employment of Exploratory Factor Analysis (EFA), Partial Least Square Structural Equation Model (PLS-SEM), and the extension of the importance-performance matrix analysis (IPMA). Our results showed the reliability and validity of 21 measured items under 5 PCI sub-indices. The findings confirmed the positive impact of the PCI index on growth. Moreover, the highest importance but lowest performance of SLO (law and order) was implied. SLA (land access and security of tenure), on the contrary, peaked the performance with the lowest importance. The importance of STC (time costs and regulatory compliance), SPA (proactive provincial leadership), and SLP (labor quality) has been ranked with the former sharing the highest priority while similar performance of the four sub-indices has been found. The results implied that the provincial authorities should prioritize their efforts to improve governance based on the importance-performance analysis of PCI sub-indices. Moreover, the importance and performance of each sub-index indicator reflected the great governance improvement with an average performance of 50%. However, special attention should be focused on vocational training, effective state officials, and legal support to the business due to their high importance but low performance

SIMULATION AS A TEACHING METHOD FOR NURSING EDUCATION IN HEALTHCARE-ASSOCIATED INFECTION PREVENTION AND CONTROL IN ASIAN COUNTRIES: A QUALITATIVE STUDY

BACKGROUND: Applying simulation for nursing education, especially in healthcare-associated infection prevention and control (HAI-PC) in developing countries has limited evidence. The study was conducted to explore educators’ perceptions of simulation as a teaching method for nursing education in HAI-PC in two Vietnamese and two Cambodian universities. METHODS: An exploratory qualitative design was applied. A focus group of 37 educators from four universities was conducted for data collection. Inductive and deductive qualitative content analysis was applied in analysing the data. RESULTS: The core category was constructed to reflect educators’ perception of scenario-based simulation (SBS) as a teaching method for nursing education in HAI prevention and control. This main category included three subcategories: (i) enhancing nursing competence; (ii) preparing students for simulation; and [1] promoting simulation pedagogy competence. CONCLUSIONS: The findings identified the importance and benefits of applying simulation as a teaching method in nursing education. Additionally, it emphasized the necessity of enhancing knowledge associated with HAIs and providing additional training on simulation for educators to improve the quality of conducting simulations

EXPERIENCES OF THE NURSING STUDENT IN LEARNING HAI PREVENTION AND CONTROL IN ASIAN COUNTRIES THROUGH THE USE OF SCENARIO-BASED SIMULATION: AN EXPLORATIVE QUALITATIVE STUDY

BACKGROUND: Healthcare-associated infections (HAIs) have posed a major threat to both patients and to the safety healthcare personnel worldwide. According to the World Health Organization, 10% of hospitalized patients are affected by HAIs worldwide. OBJECTIVE: The objective of this study was to explore the experiences of nursing students in learning HAIs prevention and control by the application of the scenario-based simulation pedagogy now in use in two Vietnamese and two Cambodian universities. METHODS: A qualitative study was conducted among 160 nursing students from 2 Cambodian universities and 2 Vietnamese universities, and by using the purposive-sampling method. The data were collected through a focus group discussion and analyzed by the Graneheim and Lundman method (Graneheim & Lundman, 2004). RESULTS: Two themes and six categories were generated. 1) First theme: factors for enhancing student learning on the prevention and control of HAIs by use of scenario-based simulation; and 2) Second theme: factors hindering students learning on HAI prevention and control by use of scenario-based simulation. CONCLUSION: The findings showed that SBS is an effective learning method for nursing students that can be applied to enhance the quality of nursing education in the Asian countries as SBS not only improves the clinical skills, but also the soft skills of nursing students. However, the effective outcomes and impacts can only be achieved in the context with the appropriate learning materials and equipment, simulation facilities and the instructors with pedagogical skills

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

Modification of theory A.R. Rzhanitsyn in analysis of multilayer composite beams

The article proposes the development of a numerical method for calculating multilayer beams, based on the theory of composite rods by A.R. Rzhanitsyn. The modification of this theory is to simplify the calculation model for a determined class of structures. It is considered multilayer beams composed of same layers of rectangular cross section, with the same physical and mechanical characteristics. The stiffness of all connecting seams is taken equal. In the research the hypothesis of a functional relationship between shear forces in the seams of the structure is taken. This allows the authors to significantly reduce the dimension of the system of resolving differential equations, from n + 2 equations to three for any finite number of layers. Where n -is the number of seams, and, accordingly, the number of shear forces to find in the seams according to the A.R Rzhanitsyn model, n + 1 is the number of layers. A comparison of three models of the above dependence is given. The numerical methodology is based on the approximation of differential equations by difference equations of the method of successive approximations (MSA). This methodology has proven itself well in the calculation of beams, plates, shells for the action of static loads, in calculations in a dynamic setting and for stability, on an elastic foundation. Including multilayer beams and plates. It allows to take into account the finite discontinuities of the load parameters, stiffness parameters of the structure and foundation. The described methodology can find application in the practice of design organizations and enter the educational courses of higher educational institutions of the construction profile

Oxidation of carbon nanotubes using for Cu(II) adsorption from aqueous solution

Carbon nanotubes (CNTs) synthesized by chemical vapour deposition without using hydrogen were oxidized with 0.1 M potassium permanganate at 40oC for 2 hours and exhibited high CuII adsorption capacity from aqueous solution. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM), transmission electron microscope (TEM) and nitrogen adsorption/desorption isotherms were used to characterize the oxidized CNTs. After oxidizing, the obtained CNTs were used to remove CuII from aqueous solution. With CuII initial concentration of 20 mg.L-1, at pH of 4 and adsorbent dosage of 0.2 g.L-1, the oxidized CNTs exhibited high CuII adsorption ability with maximum adsorption capacity of 174.4 mg.g-1

NGHIÊN CỨU MỘT SỐ ĐẶC TRƯNG HÓA LÝ CỦA BÙN ĐỎ TÂN RAI, LÂM ĐỒNG

In the present paper, physico-chemical characterizations including chemical composition, crystal phase composition, particle size distribution, particle morphology, physico-chemical processes during the sintering, functional groups on the surface of Tanrai red mud (Lamdong, Vietnam) were investigated. Tanrai red mud was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), lazer diffraction, thermogravimetry and differential scanning calorimetry (TG-DSC), scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier-transform infrared spectroscopy (FT-IR) analyses. The results showed that main crystal phases of red mud were hematite (Fe2O3), goethite (FeO(OH)) and gibbsite (Al(OH)3). The amounts of Fe2O3 (46,7%), Al2O3 (19,1%), Na2O (4,4%), TiO2 (5,9%) in red mud were rather high that were suitable for manufacturing iron and steel, unsintered bricks, sintered bricks, and recovering TiO2. High alkaline amount (pH &gt; 11) of red mud with small particle size is a factor strongly concerning water and air polutions.Bài báo trình bày một số đặc trưng hóa lý: thành phần hóa học, thành phần pha tinh thể, phân bố cấp hạt, hình thái và kích thước hạt, các quá trình hóa lý xảy ra khi nung, các nhóm chức đặc trưng của bùn đỏ Tân Rai, Lâm Đồng, Việt Nam. Các đặc trưng của bùn đỏ được xác định bằng các phương pháp nhiễu xạ tia X (XRD), huỳnh quang tia X (XRF), tán xạ laze, phân tích nhiệt (TG-DSC), hiển vi điện tử quét (SEM), hiển vi điện tử truyền qua (TEM), phổ hồng ngoại (FT-IR). Kết quả cho thấy: thành phần pha tinh thể của bùn đỏ chủ yếu là hematite (Fe2O3), goethite (FeO(OH)) và gibbsite (Al(OH)3). Hàm lượng các oxit Fe2O3 (46,7%), Al2O3 (19,1%), Na2O (4,4%), TiO2 (5,9%) khá cao, có thể sử dụng bùn đỏ làm nguyên liệu để sản xuất sắt thép, gạch không nung, gạch nung, thu hồi TiO2. Bùn đỏ có môi trường kiềm mạnh (pH &gt; 11), cấp hạt nhỏ,  có khả năng gây ô nhiễm môi trường nước và không khí