THE ANALYSIS OF FLUID DYNAMICS OF WAVE POWER STATION WITH WELLS TURBIN BY CFD

Natural energy such as wind, wave and other natural vibrations is one of the high potential renewable energy sources. The Wells turbine is based on the use of bidirectional turbines, which act as axial-flow self-rectifying turbines that employs a symmetrical blade profile and rotating unidirectionally in reciprocating airflows generated by the air chamber to extract energy from vibrations. These topics have been extensively studied both numerically and experimentally such as research on the parameters of the effects of structure, angle of attack, blade shape, etc. In this paper, numerical simulation is carried out using commercially available tool Fluent for fluid dynamics analysis and focus on oscillating predictions, with particular attention to the behavior of the flow. Based on the Numerical Wave Tank (NWT) model is simulated in a two dimensional used in this model, which is constructed mainly based on the spatially averaged Navier Stokes equation with the k-ε model for simulating the turbulence and modeled with Volume of Fluid (VOF). Axial-flow turbines system and future development as well as the proposed limitations will be discussed in detail

Saprochaete Capitata Infection in an 80–Year Old Chronic Obstructive Pulmonary Disease (COPD) Patient: A Case Report

BACKGROUND: The fungal disease caused by invasive fungus Saprochaete capitata is becoming an increasingly popular infection. Fungal pathogens mainly occur in patients with immunocompromised disorders such as hematologic malignancies, acute myeloid leukemia, transplant patients. CASE REPORT: In this study, we presented a COPD patient infected with S. capitata. At the first check, the patient showed cough, dyspnea, chest pain on both sides. The clinical laboratory test result was characterized with high White blood cell (12.8 G/L), HIV negative. The X ray showed bronchitis and emphysema. Bronchoscopy illustrated bronchial mucositis. CT scanner demonstrated pneumonia with fuzzy nodular lesions and thick interstitial organization in both lungs. The patient was treated with ciprofloxacin 800 mg/day; cefuroxime 2250 mmg/day. However, the fever appeared 2 weeks thereafter. The S. capitata was discovered in the bronchial fluid. The patient was then treated with fluconazole 400 mg/day for 14 days. At the end of treatment, all signs and symptoms of S. capitata infection disappeared and the patient recovered. CONCLUSION: This case study showed that S. capitata infection can occur in the COPD patients and fluconazole is a pertinent drug for treatment of the infection

An adaptive hierarchical sliding mode controller for autonomous underwater vehicles

The paper addresses a problem of efficiently controlling an autonomous underwater vehicle (AUV), where its typical underactuated model is considered. Due to critical uncertainties and nonlinearities in the system caused by unavoidable external disturbances such as ocean currents when it operates, it is paramount to robustly maintain motions of the vehicle over time as expected. Therefore, it is proposed to employ the hierarchical sliding mode control technique to design the closed-loop control scheme for the device. However, exactly determining parameters of the AUV control system is impractical since its nonlinearities and external disturbances can vary those parameters over time. Thus, it is proposed to exploit neural networks to develop an adaptive learning mechanism that allows the system to learn its parameters adaptively. More importantly, stability of the AUV system controlled by the proposed approach is theoretically proved to be guaranteed by the use of the Lyapunov theory. Effectiveness of the proposed control scheme was verified by the experiments implemented in a synthetic environment, where the obtained results are highly promising. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Linh Nguyen" is provided in this record*

Pulse-width modulation direct torque control induction motor drive with Kalman filter

The paper deals with application of Kalman filter in induction motor drive using pulse-width modulation direct torque control (PWM-DTC). In the first part, the conventional PWM-DTC drive is described and Kalman filter is utilized to filter components of stator current vector those are assumed to be disturbed by white noise. The second part contains simulation results that are obtained in different cases of load torque, process and measurement noise covariances. The integral time absolute error (ITAE) performance index, undershoot, ripple of important quantities are used to compare the conventional drive structure and proposed drive structure with Kalman filter. The simulation results confirm the expected dynamic response of the proposed structure

VỀ CHỈ SỐ CHÍNH QUY CASTELNUOVO-MUMFORD CỦA VÀNH TỌA ĐỘ CỦA TẬP n + 3 ĐIỂM BÉO KHÔNG SUY BIẾN TRONG KHÔNG GIAN XẠ ẢNH Pn

In this paper we calculate the Castelnuovo-Mumford regularity index of the coordinate ring of n + 3 a set of  non-degenerate fat points in Pn for almost all of cases.Trong bài báo này chúng tôi tính chỉ số chính quy Castelnuovo-Mumford của vành tọa độ của tập n + 3 điểm béo không suy biến trong Pn cho hầu hết các trường hợp của tập điểm

Interpretation of 1H-NMR spectrum of alginate by 1H-1H TOCSY and COSY spectrum

The sodium alginate was prepared from brown seaweeds in Thua-Thien-Hue coastal area. The obtained alginate was characterized by 1H-NMR, 1H-1H TOCSY and COSY spectra. The  assignment of alginate peaks in 1H-NMR spectrum is 5.09, 4.446, 4.152, 4.318, 4.135 ppm in correspondence to H1, H2, H3, H4, H5 of D-mannuronic acid and 5.473, 4.318, 4.446, 4.571, 4.883 ppm in correspondence to H1, H2, H3, H4, H5 of L-guluronic acid, respectively. The present results are essential for the investigating guidance of alginate and its derivatives

Quality of life among urban hypertensive patients

Hypertension is a leading risk factor for major chronic illnesses. This study investigated the quality of life (QOL) of hypertensive patients in an urban setting and evaluate related factors. A cross-sectional study on 220 hypertensive patients was performed in Hanoi, Vietnam. Short-form 12 version 2 (SF12-v2) was used to assess QOL. Sociodemographic and clinical characteristics were also obtained. Multivariate regression was utilized to explore the related factors with patients’ QOL. The mean physical health (PCS-12) and mental health (MCS-12) scores were 43.3 (SD=7.9) and 56.3 (SD=6.5), respectively, Higher age was related to a lower PCS-12. People living in low-population-density settings have a higher MCS-12 score than those living in high-density settings. Increasing comorbidity and medication reduced both component scores. Patients participating in social activity had the MCS-12 score higher than those not participating. This study found a moderate level of health-related quality of life (HRQOL) in hypertensive patients regardless of treatment progress. Regular screening and controlling comorbidities, as well as motivating active employment and social activities involvement, are the potential to enhance the HRQOL of this population

Why adaptation falters:principles for climate change adaptation policy assessment in Vietnam

PurposeRecognition that not every climate adaptation policy is a good one has shifted attention to new tools and methods to measure the adequacy and effectiveness of adaptation policies. This study aims to propose and apply and applies an innovative adaptation policy assessment framework to identify the extent to which climate adaptation policies in Vietnam exhibit conditions that are likely to ensure a sufficient, credible and effective adaptation.Design/methodology/approachIn total, 21 conditions, categorized under five normative principles and covering critical issue areas in adaptation domain, form the climate adaptation policy assessment framework. The principles were double-checked and tested in case studies through observations and analyses of policy documents to ensure that each condition should be distinct and not overlapping across principles. To see if the principles and attendant conditions were able to capture all relevant aspects of adaptation, the authors used structured expert judgment. In total, 39 policy documents pertaining to climate change adaptation were selected for qualitative document analysis. In-depth interviews with local officials and experts were conducted to address data gaps.FindingsThe study reveals major weaknesses constituting a reasonably worrisome picture of the adaptation policies in Vietnam since several critical conditions were underrepresented. These results shed new light on why some adaptation policies falter or are posing adverse impacts. The findings suggest that a sound policy assessment framework can provide evidence on what effective adaptation policy looks like and how it can be enabled. The framework for climate adaptation policy assessment in this study can be easily adjusted and used for different socio-environmental contexts in which new conditions for policy assessment might emerge.Social implicationsThe findings show underlying weaknesses constituting a reasonably worrisome picture of the adaptation regime in Vietnam. In the absence of mechanisms and measures for accountability and transparency in policy processes, adaptation in Vietnam appears more likely to be prone to maladaptation and corruption. While solving these problems will not be easy for Vietnam, the government needs to evaluate whether the short-term gains in sustaining the existing adaptation policies really make progress and serve its long-term climate-adaptive development goals.Originality/valueAlthough interpretations of adaptation effectiveness may be very divergent in different normative views on adaptation outcomes, the authors argue that a common, agreed-upon effectiveness can be reached if it is clearly defined and measurable in adaptation policies. Thus, the climate adaptation policy assessment framework proposed in this study is critical for policymakers, practitioners, donors and stakeholders dealing with adaptation to better understand the weaknesses in policymaking processes, pinpoint priority areas of action and timely prevent or prepare for possible adverse impacts of policies