92 research outputs found
Influence of magnetic field on properties of electrodeposited FeCo layer
Effect of magnetic field on the electrodeposition of FeCo layers has been investigated with respect to the orientation of the magnetic field to surface electrode e.g magnetic field is parallel and perpendicular to electrode. Electrochemical behaviours, morphology, composition, structure and magnetic properties were investigated using cyclic voltammogram (CV), Scanning Electron Microscopy (SEM), Energy Dispersion Spectroscopy (EDS), X-Ray Diffractometer (XRD), Vibrating Sample Magnetometer (VSM). Results show that morphology and structure of the deposited layers are not effected by external magnetic field. Meanwhile, the Fe content of the layer decreases by following sequence CFe(B=0)CFe(B//)CFe(^), resulting in the following sequence of coerciviy HC(B=0) HC (B//) HC (^). These results were explained based on the magnetohydronamic (MHD) effect caused by the Lorentz force () when magnetic field is superimposed
BACH HO FIELD GEOLOGICAL FEATURES IDENTIFICATION USING WELL LOGGING DATA
Link for citation: Nguyen Xuan Kha, Pham Xuan Son, Hoang Van Quy, Nguyen Tuan, Truong Quoc Thanh, Mai Huu Xuan, Tran Van Xuan. Bach ho field geological features identification using well logging data. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр. 35-42. In Rus.
The relevance. Well geophysics is considered as a typical method that can assist in determining the petrophysics properties of reservoirs and further location of the petroleum product-containing reservoirs. For reservoirs formed from fractured basement rock, studies on the petrophysics properties of fracture zones can contribute to the identification of petroleum products. The main aim. The study applied the cross-plotting method based on raw well-logging data to identify the possible correlation between the gamma-ray logging with well-logging including neutron porosity, sonic transient time, and bulk density in three wells (BH-433, BH-809, and BH-905) of Bach Ho field in the Cuu Long Basin, Vietnam. Methods. To deploy this study, well-logging data were integrated into formation of micro images and neutro, speed of sound, and density of the basement at the surveyed reservoir positions. Results. The results indicated that granite in the investigated zones responds to the two tight value ranges (no-oil exist zones) neutro (0,000–0,100) and speed of sound (46–64), and neutro (0,000–0,100) and density (2,375–2,750) while the value ranges deviate from 0,000–0,100, 46–64, and 2,375–2,750, respectively for neutro, speed of sound, and density are closely related to the good permeability and porosity zones (oil exist zones). Based on the findings, it can be confirmed that the cross-plotting analysis has contributed positively to the initial assessment of potential ranges of the oil reservoirs in Bach Ho field. The application of the cross-plotting method will contribute to enhancing the predictability of oil and gas in the reservoirs
HIGH PERFORMANCE LIQUID CHROMATOGRAPHY ASSAY FOR DETERMINATION OF MOXIFLOXACIN IN HUMAN PLASMA
A simple reversed phase HPLC method with UV detection has been successfully developed and validated for determination of moxifloxacin in human plasma. The sample pretreatment involves only single-step protein precipitation with tricloroacetic acid. Moxifloxacin was measured in plasma using a validated HPLC method with UV detector at 295 nm, C18 column (25cm×4.5mm, 5µm), a mixture of phosphate buffer pH 4.0 and acetonitrile (70:30, v/v) as mobile phase at a flow rate of 0.8 ml/min. Retention time of moxifloxacin was found to be 7.4 min. The mean recovery for the drug was obtained 97.30%. The calibration curve was linear over the concentration range of 0.3 to 25.0 µg/mL with coefficient correlation of 0.9991. This method was successfully applied for therapeutic drug monitoring
Mangrove restoration in Vietnamese Mekong Delta during 2015-2020: Achievements and challenges
Mangrove forest in the Mekong Delta plays important roles in protecting coasts from soil erosion and strong waves, supplying seafood, and accumulating carbon. Despite these benefits, mangroves have been and continue to be severely damaged by the impacts of natural and socioeconomic activities. In recent years, large areas of mangrove forest have been restored through planting and other various management actions. In this study, we analyzed high-resolution WorldView-2 images to quantify changes in the mangrove forest in seven coastal provinces (Tien Giang, Ben Tre, Tra Vinh, Soc Trang, Bac Lieu, Ca Mau, and Kien Giang) of the Mekong Delta from 2015 to 2020. Our study is one of the first to analyze mangrove forest change at the commune scale, the smallest official administrative unit in Vietnam, to determine the area of restored mangroves. The potentials and challenges in future mangrove restoration were also assessed by analyzing satellite imagery and field survey data. In the study area, mangrove forest area increased by 11,184 ha (approximately 2,237 ha per year) from 79,593 ha in 2015 to 90,777 ha in 2020. A total area of 16,138 ha (approximately 20.3%) was lost due to mangrove conversion to other land uses, aquaculture activities and coastal erosion, etc., while 27,322 ha (approximately 34.1%) was restored or newly planted during state- and NGO-funded mangrove restoration projects and programs. These results confirmed that mangrove restoration projects and programs have played a significant role in maintaining and increasing mangrove forest cover in Mekong Delta. The results can also assist managers and decision makers in mangrove restoration evaluation, and suggest analyzing WorldView-2 images to monitor mangrove restoration over time in Vietnam
Corrigendum: Mangrove restoration in Vietnamese Mekong Delta during 2015-2020: achievements and challenges
TextANIMAR: Text-based 3D Animal Fine-Grained Retrieval
3D object retrieval is an important yet challenging task, which has drawn
more and more attention in recent years. While existing approaches have made
strides in addressing this issue, they are often limited to restricted settings
such as image and sketch queries, which are often unfriendly interactions for
common users. In order to overcome these limitations, this paper presents a
novel SHREC challenge track focusing on text-based fine-grained retrieval of 3D
animal models. Unlike previous SHREC challenge tracks, the proposed task is
considerably more challenging, requiring participants to develop innovative
approaches to tackle the problem of text-based retrieval. Despite the increased
difficulty, we believe that this task has the potential to drive useful
applications in practice and facilitate more intuitive interactions with 3D
objects. Five groups participated in our competition, submitting a total of 114
runs. While the results obtained in our competition are satisfactory, we note
that the challenges presented by this task are far from being fully solved. As
such, we provide insights into potential areas for future research and
improvements. We believe that we can help push the boundaries of 3D object
retrieval and facilitate more user-friendly interactions via vision-language
technologies.Comment: arXiv admin note: text overlap with arXiv:2304.0573
Risk Factors of Streptococcus suis Infection in Vietnam. A Case-Control Study
Background: Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors underlying the disease. Methods and Findings: A case-control study with appropriate hospital and matched community controls for each patient was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating "high risk" dishes, including such dishes as undercooked pig blood and pig intestine (OR1 = 2.22; 95% CI = [1.15-4.28] and OR2 = 4.44; 95% CI = [2.15-9.15]), occupations related to pigs (OR1 = 3.84; 95% CI = [1.32-11.11] and OR2 = 5.52; 95% CI = [1.49-20.39]), and exposures to pigs or pork in the presence of skin injuries (OR1 = 7.48; 95% CI = [1.97-28.44] and OR2 = 15.96; 95% CI = [2.97-85.72]). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2 rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection. Conclusions: This case control study, the largest prospective epidemiological assessment of this disease, has identified the most important risk factors associated with S. suis bacterial meningitis to be eating 'high risk' dishes popular in parts of Asia, occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors can be addressed in public health campaigns aimed at preventing S. suis infectio
Awareness and preparedness of healthcare workers against the first wave of the COVID-19 pandemic: A cross-sectional survey across 57 countries.
BACKGROUND: Since the COVID-19 pandemic began, there have been concerns related to the preparedness of healthcare workers (HCWs). This study aimed to describe the level of awareness and preparedness of hospital HCWs at the time of the first wave. METHODS: This multinational, multicenter, cross-sectional survey was conducted among hospital HCWs from February to May 2020. We used a hierarchical logistic regression multivariate analysis to adjust the influence of variables based on awareness and preparedness. We then used association rule mining to identify relationships between HCW confidence in handling suspected COVID-19 patients and prior COVID-19 case-management training. RESULTS: We surveyed 24,653 HCWs from 371 hospitals across 57 countries and received 17,302 responses from 70.2% HCWs overall. The median COVID-19 preparedness score was 11.0 (interquartile range [IQR] = 6.0-14.0) and the median awareness score was 29.6 (IQR = 26.6-32.6). HCWs at COVID-19 designated facilities with previous outbreak experience, or HCWs who were trained for dealing with the SARS-CoV-2 outbreak, had significantly higher levels of preparedness and awareness (p<0.001). Association rule mining suggests that nurses and doctors who had a 'great-extent-of-confidence' in handling suspected COVID-19 patients had participated in COVID-19 training courses. Male participants (mean difference = 0.34; 95% CI = 0.22, 0.46; p<0.001) and nurses (mean difference = 0.67; 95% CI = 0.53, 0.81; p<0.001) had higher preparedness scores compared to women participants and doctors. INTERPRETATION: There was an unsurprising high level of awareness and preparedness among HCWs who participated in COVID-19 training courses. However, disparity existed along the lines of gender and type of HCW. It is unknown whether the difference in COVID-19 preparedness that we detected early in the pandemic may have translated into disproportionate SARS-CoV-2 burden of disease by gender or HCW type
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