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This study investigates the entropy generation and heat transfer of water density inversion region in a square cavity with the different relative positions of hot and cold walls by numerical simulation. Mathematical models are solved using the EES (Engineering Equation Solver) program. A physical model is a 38 mm square cavity filled with water, with cold and hot wall temperatures maintained at 0oC and 10oC. Results indicated that the Nusselt number of cases 1 (cold and hot walls on both sides) is higher than case 2 (hot wall above, cold wall below) and case 3 (cold wall above, hot wall below) by 1.582 and 1.059 times, respectively. The average total generation per unit volume in case 1 increases by 1.577 times and 1.059 times, respectively, compared to cases 2 and 3, which almost correspondingly increase with heat transfer capacity. Entropy generation by fluid friction is negligible

Intestinal hypoganglionosis in adults is quite uncommon, and hypoganglionosis of the ileum has not been documented to date. The majority of studies on this disorder are single case reports and brief case series. We describe a 30-year-old male patient with bowel obstruction and intestinal hypoganglionosis of the ileum and we review the literature on the disorder.

Acinic cell carcinoma (ACC) is a rare malignant tumor of the salivary glands that accounts for 6%-10% of all salivary gland malignancies. It has a propensity to considerably recur, metastasize to the lung or cervical lymph nodes. In addition, ACC can potentially be fatal. The parotid gland is where ACC most frequently begins. The purpose of this paper was to describe an unusual case of parotid gland ACC in a 58-year-old Vietnamese adult female. Before surgery, a fine-needle aspiration biopsy revealed the existence of tumor cells with acinar differentiation. Following that, she underwent successful surgery without complications. The existence of ACC was verified by the postoperative final histologic results.

Geometry, stability, electronic structure, and magnetic properties of Ge14M clusters with M being a 3d transition metal atom, from Sc to Zn, were studied using density functional theory (DFT) calculations at B3PW91/6-311+G(d) level. The obtained results found that Ge14M clusters preferentially exist in its lowest possible spin state, except for M being Fe and Cr. The thermodynamic stability of the structures has been evaluated through the average binding and embedded energies. Ge14Ti and Ge14V clusters are considered to be the most stable in the Ge14M series (M = Sc - Zn) with the geometry of the C2 point group where M is located in the center of the Ge12 hexagonal prism along with two Ge-atoms capping on two Ge6 faces. In this series Ge14M clusters, only Ge14Fe cluster is stable at the high spin state, with a magnetic moment of 2mB.

The development of robotics is undeniable in recent years. Many developing contries face the growth of the elderly population, it is the premise and impetus for the development of research on humanoid robots to serve humans. Many studies on various aspects of robotics are carried out in different parts of the world. Many novel methods were introduced for the design of the robot’s external appearance, internal mechanisms, and gestures. Recent research on humanoid robots is designed to appear to be copies of the anthropometric indicators of real people, which may affect the security of other people’s identities. Besides, these robots cause a feeling of horror in the user if their appearance is in the position of the uncanny valley. Therefore, these designs need to be carefully considered before fabrication. Artificial skin is studied for various purposes such as ensuring collision safety for industrial users and helping robots to perceive basic tactile sensations. This review consists of the recent literature on the interaction of appearance and behavior of robot interaction, artificial skin, and especially humanoid robots, including appearance, such as android and Geminoid robots. This work can provide a reference for humanoid robot research, including uncanny valley hypotheses, artificial skin, and humanoid robots.

The COVID-19 pandemic raised an unprecedented race in biotechnology in search for effective therapies and a preventive vaccine. Scientists worldwide have been attempting to stop the viral infection by interfering with the biological function of the SARS-CoV-2 main protease (Mpro), a critical protein required for viral transcription and replication during infection. In this study, we employed an effective approach integrating deep learning model calculations and steered molecular dynamic simulations to generate highly promising inhibitors of SARS-CoV-2 Mpro. First, using deep learning calculations, a natural molecule that was identified as a potential inhibitor of SARS-CoV-2 Mpro was chemically altered to boost its ligand-binding affinity to the Mpro protease. The proposed compounds were then verified using steered molecular dynamic simulations to estimate their binding free energies to SARS-CoV-2 Mpro. The procedure was repeated until the binding free energies of the proposed compounds did not improve further. Overall, one proposed compound was shown to have a high nanomolar affinity, and two others were estimated to possess nanomolar affinities for SARS-CoV-2 Mpro, indicating that they are highly promising inhibitors of the protease. Absorption, distribution, metabolism, and excretion and toxicity analysis show that all three chemicals are drug-like compounds following the MACCS-II Drug Data Report database, orally absorbed, tightly attached to the plasma membrane, and noncarcinogenic in rats. The results obtained potentially support COVID-19 treatment.

Popular sovereignty is one of the important issues in the content of the constitutions. The perception and expression of popular sovereignty in Vietnam’s constitutions have many dissimilarities. The constitutions of Vietnam of 1959, 1980, and 1992 were rather limited and inadequate in scope with regards to popular sovereignty. Even though the 2013 Vietnam Constitution has presented more comprehensive popular sovereignty than the previous constitutions of Vietnam, further investigation and refinement are still needed. This article gives a number of suggestions to achieve more adequate and full expression of popular sovereignty in the 2013 Vietnam Constitution., The Constitution of Vietnam through the Lenses of Cognitive Constitutionalism

"Cam" rice bran was considered a waste product from rice, which is rich in natural compounds and protein owing to its outstanding nutritional value. This study aimed to establish an optimization model for extracting protein from rice bran, with two responses: extraction yield (%) and protein content (%). The variable parameters included were pH (8.5-9.5), stirring time (3.5-4.5 h), and enzyme incubation temperature (85-95°C). The coefficient of determination for both models were above 0.95, indicating a high correlation between the actual and estimated values. The maximum extraction yield and protein content were achieved when the conditions were set at pH of 9.02, stirring time of 4.02 h, and extraction temperature of 90.6°C. Under these optimum conditions, the predicted protein extracted from rice bran was 43.03% (moisture

In this paper, we are interested to study a nonlinear Volterra equation with conformable deriva- tive. This kind of such equation has various applications, for example physics, mechanical engineering, heat conduction theory. First, we show that our problem have a mild soltution which exists locally in time. Then we prove that the convergence of the mild solution when the parameter tends to zero.

The combustion of diesel engines is mainly controlled by fuel injection. Determining the fuel injection flow rate combined with the common-rail fuel injection system is a key solution to effectively improve engine performance and exhaust emissions. This work aims to investigate the influence of high injection pressures with a 6-holes-solenoid common rail injector on the injection rate characteristics in the range of 400 bar to 1600 bar, and a constant injector energizing time of 1.5 ms. The injection rate characteristics were carried out based on the pressure difference in the Zuech measuring chamber and synchronized data in real-time. The results showed that the increase of the mentioned injection pressures caused the decrease of hydraulic injection delay from 0.5 ms to 0.25 ms and expansion of the injector opening angle profile. In addition, the actual opening injection interval was prolonged as compared to the injector control signal. An increasing trend of fuel discharge coefficient was realized as higher injection pressure.

In this paper, a 2D numerical simulation of a solar chimney with a top V cap was performed to evaluate the induced air flow degradation. Dimensions including the width of the cap and the cap offset from the top of chimney are specified as key parameters. Meanwhile, height and width of the chimney are fixed. The numerical model was confirmed to be accurate compared to the published data. The results showed that reducing the offset and increasing the width reduces airflow through the chimney. The effect of offset on chimney intake air is significant. When considering the addition of the top V cap, the airflow is reduced by about 20% compared to the chimney without a cap. This is because the cap forms three primary vortices including one vortex below the cap and two ones above the cap. The vortex under the cap in the direction from the absorber plate to the glass cover increases the air flow out of chimney at the side of the glass cover. The region with great turbulent kinetic energy forms at upper side of the cap. The air flow correlation as a function of the heat flux to the absorber plate, cap offset and cap width have been developed with errors of less than 2.5%.

This study aims to explore the effect of employer attractiveness on employee engagement in depth. The analytical method in quantitative research is PLS-SEM. The survey sample, through the survey questionnaires, was collected from 937 respondents as employees from 37 enterprises operating in Vietnam. Employer attractiveness has a positive impact on employee engagement with a high coefficient. This result helps to demonstrate the new research direction that employer attractiveness affects not only the potential candidates but also the existing employees.

Chukrasia tabularis A. Juss produces a valuable timber but plantations are susceptible to attack by the shoot-tip borer Hypsipyla robusta Moore. An integrated pest management (IPM) approach is desirable to limit the extent of damage. Therefore, this study was undertaken to evaluate the deployment of IPM measures in plantations in Vietnam. Data on tree damage and the biology of H. robusta were gathered in 4 provinces over one year and used to build an investigation schedule. Two preliminary IPM trials were then established in which Bacillus thuringiensis and Metarhizium anisopliae were applied to the foliage when the damage incidence (P%) was in the range 5–10%; and insecticides (Carbaryl, Carbosulfan) were applied when the P% exceeded 10%. In addition, larvae and pupae were removed manually over time. In the first trial, the combination of manual and biological control methods reduced the damage index (DI) of trees from 4 tolerant families by 82% compared to the untreated control plots. In the second trial using standard planting stock, application of insecticides was required to reduce the DI by 83%. Six extended IPM trials were undertaken using the same IPM protocols and these reduced the DI to the same extent as in the preliminary trials. Over an 18-month period, the deployment of IPM increased height growth by 19–22% and diameter growth by 38–41% compared to the controls. These findings highlight the value of planting improved seed and the benefit of adopting an IPM approach to manage the shoot-tip borer.

This article analyzed results of experimenting of 3 groups of measures with 8 specific measures for the development of listening and speaking skills for children with hearing impairment aged 3-6 years in kindergarten-based daily routines include: (1) Group of conditional measures; (2) Group of measures for the development of listening and speaking skills in kindergarten-based daily routines; (3) Group of measures for the development of listening and speaking skills through individualized support. The experiment was conducted on 3 children with hearing impairment who use sensory devices, aged 3-6 years, and attend inclusive kindergartens. The experimental results analyzed both qualitatively and quantitatively showed that the listening and speaking skills in all 3 cases have significantly improved, although there are differences in level. The development of the 3 case studies on listening and speaking skills proves the feasibility and effectiveness of the measures on the experimental subjects and also shows that the development of listening and speaking skills for children with hearing impairment is influenced by many factors, of which there are three most significant factors including: (1) sensory devices that they wear; (2) hearing age (the period the children wear a sensory device counted from the time they start wearing it); (3) early intervention.