A SIMPLIFIED ASSESSMENT OF THE LOAD BEARING CAPACITY OF SUCTION CAISSON FOR OFFSHORE WIND TURBINES BASED ON FINITE ELEMENT ANALYSIS

Suction caisson is widely used for offshore wind turbine applications. Its loadbearing capacity depends on the bucket geometry and its embedded soil properties. This paper presents a simplified assessment of the loadbearing capacity of suction caisson based on finite element analysis using the Plaxis 2D program. The load-bearing capacity of the suction caisson is determined based on the resulting load-displacement curve via the tangent intersection method. In addition, this study developed an equivalent equation exploring the relationship between the load-bearing capacity of the suction caisson and the surface foundation. The findings in the study showed that the geometry of the suction has a significant influence on its loadbearing capacity. The suction caissons whose aspect ratios are larger resulted in higher loadbearing capacities. Besides, the equivalent equation in this study could be applied to effectively estimate the load-bearing capacity of suction caisson based on its geometry. The finite element program and the soil ground model analyzed in this study was only an assumption. In the future, experimental studies should investigate the loadbearing capacity of a suction caisson related to its geometry and the embedded soil profile using centrifuge models and large-scale models

Frequency and Risk Factor of Lower-limb Deep Vein Thrombosis after Major Orthopedic Surgery in Vietnamese Patients

BACKGROUND: Deep venous thrombosis (DVT) is a prevalent complication of orthopedic surgery. According in many studies. The incidence of DVT may be up to 50% if thromboprophylaxis is not available. AIM: The objective of this study was to check the degree of disease, clinical characteristics and analyzed factors in vulnerabilities with lower-limp DVT after orthopedic surgery in a Vietnam teaching hospital. METHODS: Orthopedic patients who met criteria were recruited at our hospital between August 2017 and June 2018. Ultrasound was used to discovering lower-limp DVT in pre-surgery and 7 days after surgery in all patients. RESULTS: The incidence of DVT after orthopedic surgery was 7.2%. Patients with older age (> 60) have a risk of 2 times higher of DVT after surgery than normal people (p < 0.05). The incidence of postoperative DVT was higher in immobile individuals > 72 hours (p < 0.05). Patients with prolonged surgical time (>120 minutes) had a higher risk of postoperative DVT than non-surgical patients’ surgery (p < 0.05). CONCLUSIONS: DVT remains a common complication following orthopedic surgery. Older age, immobility status, and surgical time have been found to be risky factors for the development of postoperative lower-limp DVT in orthopedic patients

The experience of using e-commerce platforms affects the online purchase intention of customers in the FMCG (Fast moving consumer goods) sector in Hanoi city

In recent times, the Vietnamese e-commerce market is in a period of strong development, in addition, to the sharp increase in people’s demands to join e-commerce platforms after the epidemic. The research group started with an overview study, then research hypotheses and models were proposed. After conducting preliminary qualitative and quantitative research to adjust the appropriate scales, the research group created a questionnaire and collected data in online forms with a sample size of 350. Next, the data was entered into the software for SEM analysis. The results of the study indicate that the quality of the e-commerce platform has an indirect impact on the purchase intention through the positive impact on the trust and the negative impact on the perceived risk. Attitudes towards information, trust, perceived risk, and perceived usefulness have direct influences on purchase intention. Attitude towards information, trust, and perceived usefulness have positive effects on purchase intention, while perceived risk harms purchase intention. In addition, purchase intention is relatively strongly influenced by trust and perceived usefulness. Perceived risk and attitude towards information have little influence on purchase intention. Finally, the research team proposes some solutions for businesses to increase the purchase intention of consumers through e-commerce platforms. &nbsp

"Cultural additivity" and how the values and norms of Confucianism, Buddhism, and Taoism co-exist, interact, and influence Vietnamese society: A Bayesian analysis of long-standing folktales, using R and Stan

Every year, the Vietnamese people reportedly burned about 50,000 tons of joss papers, which took the form of not only bank notes, but iPhones, cars, clothes, even housekeepers, in hope of pleasing the dead. The practice was mistakenly attributed to traditional Buddhist teachings but originated in fact from China, which most Vietnamese were not aware of. In other aspects of life, there were many similar examples of Vietnamese so ready and comfortable with adding new norms, values, and beliefs, even contradictory ones, to their culture. This phenomenon, dubbed "cultural additivity", prompted us to study the co-existence, interaction, and influences among core values and norms of the Three Teachings--Confucianism, Buddhism, and Taoism--as shown through Vietnamese folktales. By applying Bayesian logistic regression, we evaluated the possibility of whether the key message of a story was dominated by a religion (dependent variables), as affected by the appearance of values and anti-values pertaining to the Three Teachings in the story (independent variables).Comment: 8 figures, 35 page

Excess polyspermy reduces the ability of porcine oocytes to promote male pronuclear formation after in vitro fertilization

Male pronucleus (MPN) formation is a very important physiological event during fertilization, which affects in vitro production of transferrable embryos. The aim of this study was to find out the correlation between the number of penetrated sperm and the occurrence of failure of MPN formation in porcine oocytes. In vitro matured porcine oocytes were fertilized in vitro with frozen epididymal sperm. Two different frozen sperm lots were tested in this study, which were different in terms of polyspermy rates. The numbers and the status of penetrated sperm in oocytes were evaluated 10 h after insemination. Under high polyspermy condition, the polyspermy rate was 83.5% with an average mean of 3.5 sperms per penetrated oocyte, whereas the percentage of polyspermy was 65.5% with an average mean of 2.4 sperms per penetrated oocyte under moderate polyspermic condition. Correlation analysis revealed a negative correlation between the number of penetrated sperm and their MPN formation percentage both in the sperm lot of high polyspermy (R = -0.560, p < 0.05) and in the sperm lot of moderate polyspermy (R = -0.405, p < 0.05) which suggests that penetration of excessive spermatozoa disables the oocyte cytoplasm to promote MPN formation

"Cultural additivity" and how the values and norms of Confucianism, Buddhism, and Taoism co-exist, interact, and influence Vietnamese society: A Bayesian analysis of long-standing folktales, using R and Stan

Every year, the Vietnamese people reportedly burned about 50,000 tons of joss papers, which took the form of not only bank notes, but iPhones, cars, clothes, even housekeepers, in hope of pleasing the dead. The practice was mistakenly attributed to traditional Buddhist teachings but originated in fact from China, which most Vietnamese were not aware of. In other aspects of life, there were many similar examples of Vietnamese so ready and comfortable with adding new norms, values, and beliefs, even contradictory ones, to their culture. This phenomenon, dubbed “cultural additivity”, prompted us to study the co-existence, interaction, and influences among core values and norms of the Three Teachings –Confucianism, Buddhism, and Taoism–as shown through Vietnamese folktales. By applying Bayesian logistic regression, we evaluated the possibility of whether the key message of a story was dominated by a religion (dependent variables), as affected by the appearance of values and anti-values pertaining to the Three Teachings in the story (independent variables). Our main findings included the existence of the cultural additivity of Confucian and Taoist values. More specifically, empirical results showed that the interaction or addition of the values of Taoism and Confucianism in folktales together helped predict whether the key message of a story was about Confucianism, β{VT ⋅ VC} = 0.86. Meanwhile, there was no such statistical tendency for Buddhism. The results lead to a number of important implications. First, this showed the dominance of Confucianism because the fact that Confucian and Taoist values appeared together in a story led to the story’s key message dominated by Confucianism. Thus, it presented the evidence of Confucian dominance and against liberal interpretations of the concept of the Common Roots of Three Religions (“tam giáo đồng nguyên”) as religious unification or unicity. Second, the concept of “cultural additivity” could help explain many interesting socio-cultural phenomena, namely the absence of religious intolerance and extremism in the Vietnamese society, outrageous cases of sophistry in education, the low productivity in creative endeavors like science and technology, the misleading branding strategy in business. We are aware that our results are only preliminary and more studies, both theoretical and empirical, must be carried out to give a full account of the explanatory reach of “cultural additivity”

Flexible Magnetic Metasurface with Defect Cavity for Wireless Power Transfer System

In this paper, we present a flexible magnetic metamaterial structure for enhancing the efficiency of wireless power transfer (WPT) systems operating at 13.56 MHz. The metasurface between transmitter (Tx) and receiver (Rx) coils of the WPT system is constructed of a 3 &times; 5 metamaterial unit cell array with a total size of 150 &times; 300 mm2. Most metamaterial structures integrated into WPT systems are in planar configurations with a rigid substrate, which limits practical applications. The proposed metasurface is fabricated on an FR-4 substrate with a thin thickness of 0.2 mm; therefore, it can be bent with radii greater than 80 mm. A defect cavity is formed in the non-homogeneous metasurface by controlling the resonant frequency of the unit cell with an external capacitor. Simulation and measurement results show that the efficiency of the WPT system is significantly enhanced with metasurfaces. The performance of the WPT system can also be optimized with suitable bend profiles of metasurfaces. This proposed flexible metasurface could be widely applied to WPT systems, especially asymmetric, bendable, or wearable WPT systems

Design, Fabrication, and Evaluation of Multifocal Point Transducer for High-Frequency Ultrasound Applications

The present study illustrates the design, fabrication, and evaluation of a novel multifocal point (MFP) transducer based on polyvinylidene fluoride (PVDF) film for high-frequency ultrasound application. The fabricated MFP surface was press-focused using a computer numerical control (CNC) machining tool-customized multi-spherical pattern object. The multi-spherical pattern has five spherical surfaces with equal area and connected continuously to have the same energy level at focal points. Center points of these spheres are distributed in a linear pattern with 1 mm distance between each two points. The radius of these spheres increases steadily from 10 mm to 13.86 mm. The designed MFP transducer had a center frequency of 50 MHz and a &#8722;6 dB bandwidth of 68%. The wire phantom test was conducted to study and demonstrate the advantages of this novel design. The obtained results for MFP transducer revealed a significant increase (4.3 mm) of total focal zone in the near-field and far-field area compared with 0.48 mm obtained using the conventional single focal point transducer. Hence, the proposed method is promising to fabricate MFP transducers for deeper imaging depth applications