509 research outputs found

    Molecular Kondo effect in flat-band lattices

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    The Kondo effect of a single magnetic impurity embedded in the Lieb lattice is studied by the numerical renormalization group. When the band flatness is present in the local density of states, it quenches the participation of all dispersive electrons in the Kondo singlet formation, and reduces the many-body Kondo problem to a two-electron molecular Kondo problem. The two-electron analog of the many-body Kondo singlet, a quantum entanglement of two spins, is stable at low temperature, and the impurity contributions to thermodynamical and dynamical quantities are qualitatively different from that obtained in the conventional Kondo effect in systems without flat bands. The existence conditions of the molecular Kondo effect in narrow band systems are also discussed

    Object-Oriented Approach: Applying ISO 21001 at Vietnamese Higher Education Institutions

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    To evaluate whether an educational institution has quality or not, requires standards that reflect all the requirements of the complex relationships operating within the educational institution. At the same time, this standard must be recognized by all nations for it to apply widely. It is in this context that the ISO 21001:2018 series of standards was published. This standard mentioned three areas of activities that an educational organization must pay attention to: training, scientific research, and community service. They are also the main activities that the educational accreditation standards refer to. To meet the requirement of quality guarantee and enhancement, a higher education institution has to apply quality assurance norms in general and quality criteria on management systems. Putting the ISO 21001 quality standard into practice is the choice of Vietnamese educational institutions to ensure they meet the requirements for improving management system quality. There are a set of quality system standards for educational organizations to satisfy their specific needs. Not following the traditional approach as they apply other ISO standard systems, Vietnamese educational institutions have chosen an object-base approach, where the beneficiaries are related to the management system of the university. They then approach the PDCA cycle to build and implement an ISO 21001 quality management system. We found that, according to this orientation, the implementation processes might be ensured given that the quality thresholds set by the university are met in order to satisfy the demands of the learners and related stakeholders. The paper aims to analyze the approach of Vietnamese educational institutions in implementing ISO 21001 standards, and at the same time identify advantages and disadvantages in developing policies in the quality management system at educational institutions. The paper also gives recommendations that can be adjusted by management at other higher education institutions to improve quality assurance activities towards sustainable development. Keywords: ISO 21001:2018, quality assurance, quality management system, PDCA (Plan-Do-Check-Act), sustainable developmen

    INTEGRATION OF CROSS-CULTURAL EXPERIENCES AND PROFESSIONAL COMPETENCIES: VIEWS FROM INTERNATIONAL EXCHANGE PROGRAMS IN HIGHER EDUCATION

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    Encouraging hospitality students in reflective and transformative learning toward a global mindset becomes an imperative for developing their cross-culturally professional competency in preparation of the future career path development. Oversea exchange programs are among the initiatives to raise personal, professional and cultural awareness for the hospitality students in a pathway to encourage cross-cultural learning among students in similar fields. However, to what extent the development of a global mindset gained from the cross-cultural experiences could help undergraduate hospitality students gain their professional competency in terms of cultural skills in the hospitality and tourism context is the main issue to be described by this study. Content analysis has been conducted on in-depth interview data given by hospitality oversea exchange students who are both current students and graduated ones. The most popular modes of international student exchanges such as team project, assignment, presentations, and travel exchanges are taken into consideration to highlight deeper insights into a mutual interest between the cross-cultural experiences and the professional competency related cultural skills. The study reveals that cultural understanding needs to be experienced in the real setting context. Furthermore, we also discovered that cultural exchange outcomes are normally obtained in the daily informal practices instead of formal studies. However, the current study is constrained within few selected countries where students have been experienced and the current partnership between the home and host Institutions. This paper provides actionable guidelines and approach for integrating the critical component of cultural exchange program in the traditional curriculum program of hospitality

    When Creative Mindset Helps Entrepreneurial Innovation in Tourism: An Examination on Demographics

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    Given the growing importance of creativity and innovation, this study explores the role of entrepreneurial demographics in determining creativity and innovation capabilities in Thailand’s tourism industry. The results from the analysis of data from 179 Thai entrepreneurs confirmed robust relationships between the dependent variables and the characteristics of growth mindset, gender, age, and educational group. Additionally, growth mindset demonstrates a significant relationship with innovation capability (both technical and non-technical). Regarding gender, female entrepreneurs demonstrated a higher prevalence of growth mindset, resulting in female gender having a significant positive influence on innovation capability regarding both technical and non-technical forms of innovation capability, while for male entrepreneurs, the presence of growth mindset had a significant positive influence only on technical innovation capability. Regarding age, entrepreneurs with an age of 51 years and above had a higher growth mindset, while younger entrepreneurs had significantly higher technical and non-technical innovation capability. Regarding the education segments, entrepreneurs who hold a master’s degree or higher have a higher growth mindset, while entrepreneurs with an education level of below a bachelor’s degree have a higher association with innovation capability. The relevant implications of these findings for academicians and practitioners are discussed

    Factors influencing well-being of special education teachers in Ho Chi Minh City, Vietnam

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    Increasing numbers of special education teachers are leaving jobs across different cultures and countries, which leads to teachers’ well-being has gotten more attention over the past decades. This study aims to investigate the levels of well-being and explore the factors influencing well-being in special education teachers in Vietnam. Special education teachers (N = 81) from three special education schools and a special education Centre in Vietnam were involved in the current study. Descriptive analysis, Pearson correlation, and multiple linear regression were used to examine the levels of well-being and determine whether life satisfaction, job satisfaction, self-compassion, and salary and benefits influencing the well-being levels among teachers. The results show a positive correlation between well-being and job satisfaction, life satisfaction, self-compassion, and salary and benefits. Additionally, multiple regression analysis reveals that life satisfaction, self-compassion, and salary and benefits influence well-being levels positively, meaning that teachers with increased life satisfaction, self-compassion, and salary and benefits have higher levels of well-being. The present findings contribute to the general discussion about the nature of well-being and the influential factors in teachers’ well-being. It is highly suggested that organizations/schools provide appropriate policies and increase the special education teachers' well-being in Ho Chi Minh City, Vietnam

    Several prognosis factors of severe pertussis in children treated at Vietnam National Children’s Hospital (2019-2020)

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    A prospective, descriptive study was conducted on 382 pediatric patients diagnosed with pertussis at Vietnam National Children’s Hospital over a two-year period, from January 1st, 2019, to December 31st, 2020. Of all patients participating in this study, children with severe conditions accounted for 30.1% (115/382). Several factors were found to be associated with the risk of this condition with odds ratios (OR) and 95% confidence intervals (CI), including a decrease in the duration of the onset phase by 5 days [OR 1.53, 95% CI: 1.002-2.34], fever [2.49, 1.18-5.24], cyanosis [9.59, 2.9-31.7], pneumonia [14.45, 6.06-34.5], pulmonary hypertension [4.15, 1.02-16.83], an increase of 10 g/l in white blood cell (WBC) count in the full blood count (FBC) test [1.39, 1.05-1.84], a 5-cycle reduction in Cycle threshold (Ct) value in the pertussis real-time PCR test [1.36, 1.01-1.84], and superinfection [3.94, 1.84-8.48 times]. A WBC count in FBC of ≥30 g/l could be used as a prognostic factor for the risk of severe illness condition (sensitivity 46.1%, specificity 90.6%), the requirement for mechanical ventilation (sensitivity 57.1%, specificity 88.5%), and mortality (sensitivity 100%, specificity 91%)

    Occurrence, Toxicity and Adsorptive Removal of the Chloramphenicol Antibiotic in Water: A Review

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    Chloramphenicol is a broad-spectrum bacterial antibiotic used against conjunctivitis, meningitis, plague, cholera, and typhoid fever. As a consequence, chloramphenicol ends up polluting the aquatic environment, wastewater treatment plants, and hospital wastewaters, thus disrupting ecosystems and inducing microbial resistance. Here, we review the occurrence, toxicity, and removal of chloramphenicol with emphasis on adsorption techniques. We present the adsorption performance of adsorbents such as biochar, activated carbon, porous carbon, metal-organic framework, composites, zeolites, minerals, molecularly imprinted polymers, and multi-walled carbon nanotubes. The effect of dose, pH, temperature, initial concentration, and contact time is discussed. Adsorption is controlled by π-π interactions, donor-acceptor interactions, hydrogen bonding, and electrostatic interactions. We also discuss isotherms, kinetics, thermodynamic data, selection of eluents, desorption efficiency, and regeneration of adsorbents. Porous carbon-based adsorbents exhibit excellent adsorption capacities of 500-1240 mg

    Optimization of protein extraction from "Cam" rice bran by response surface methodology

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    "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 <13.0%), with an extraction yield of 15.9%. The findings of this study suggested that this protocol can enhance the utilization of rice bran and might be employed on a large scale in the food industry to exploit the nutritional source

    NONLINEAR CHARACTERISTICS OF SQUARE SOLID-CORE PHOTONIC CRYSTAL FIBERS WITH VARIOUS LATTICE PARAMETERS IN THE CLADDING

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    Nonlinear characteristics of fused silica, solid-core photonic crystal fibers (PCFs) with a square array of air holes are studied numerically. We present a novel design that emphasizes the difference in air hole diameters in the photonic cladding. These PCFs have the advantages of flat dispersion, high nonlinearity, and low attenuation. Based on simulation results, three optimal structures, denoted #F1, #F2, and #F3, having anomalous and all-normal dispersions in the near-infrared range are selected to investigate characteristic properties at the pump wavelength. Such PCFs open up many possibilities for nonlinear optical applications, especially supercontinuum generation
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