Resonant Spectra of Metal Nanotoroids of Various Sizes

Nowadays, the manipulation of light by using metallic nanostructures has wide applications in photonics, optoelectronics and energy conversion. Along with other universities all over the world, the University of Arkansas is researching on nano-antennas’ design, fabrication and applications. Current research in Dr. El-Shenawee’s Terahertz Imaging and Spectroscopy Computational Electromagnetics Group, has computationally investigated the behaviors of plasmonic nanostructures by using the commercial finite element electromagnetic solver Ansys® HFSS. This work reproduced the previous work of spectral absorption enhancement of infinite and finite arrays of silver and gold nanotoroids with sizes of the inner radii: 13nm – 21nm, while outer radius of 42nm and more on an amorphous silicon absorbing layer. There are three significant factors in modeling this configuration such as surface resolution, optical properties of materials, and boundary conditions. A convergence study was performed on a gold sphere dimer with 40 nm radii and 1 nm gap between spheres. This illustrated that an at least surface resolution of 0.02 nm was needed to provide converging results in an acceptable computational time for conducted simulations. Furthermore, the Lorentz- Drude models for silver and gold were studied to obtain the optical properties. In addition, in order to reduce computation time and memory consumption by reduction of computational domain, the appropriate symmetry boundary conditions were applied. In this work, three samples of infinite arrays of gold nanotoroids with the sizes of inner radii: 50nm, 60nm and 100nm, respectively, while outer radius of 150nm were simulated as well. These gold nanotoroids were fabricated on glass substrate and then optically characterized by ellipsometry’s transmission measurement. The optical characterization was performed in Dr. Shui-Qing Yu’s Applied Nano and Bio Photonics Group. The observed differences between compute simulations and experimental results in shifting resonance frequencies were analyzed. This thesis is organized as: Part I is discussing about the finite element method, boundary conditions and Lorentz-Drude Model. Part II involves Lorentz-Drude model for gold and silver, convergence study using HFSS, simulations of infinite silver and gold nanotoroid arrays and ellipsometry transmission measurement on gold nanotoroid arrays. Part III is about conclusions and future research. The Appendix A is providing Matlab codes of Lorentz-Drude model for gold and silver

Challenges And Opportunities For The Development Of Infrastructure After ‘Oda Graduation’ - Moving Towards Sustainable Development: Case Study Of Vietnam

The research on ODA will be focused on its relation to Goal 17, the Partnership, considered a major issue by the researchers, especially in the case of Vietnam as a developing economy. ODA was mainly used for investing in economic infrastructure when Vietnam witnessed a downfall in receiving financial aid due to its significant economic growth. ODA helped Vietnam transform from one of the world’s poorest nations into a lower middle-income country and soon, this is going to lead to the ‘ODA Graduation’. However, the process has just begun. The country is still in a process of industrialization and modernization and its socio-economic situation has not been stable or solid. By all means, ODA is not only a financial resource, it also helps the country to accomplish Sustainable Development Goals (SDGs) of the UN. ‘ODA Graduation’ means that the economy of Vietnam has faced certain challenges such as increasing pressure of outbound debts; raising impact on social development or imbalance between high capital recovery investments and public-services investments. However, ‘ODA Graduation’ has brought certain opportunities such as increasing Vietnam’s independence in capital mobilization, preventing the removal of tariffs barrier, reducing losses and waste of funds. This research gives recommendations for improving Vietnam’s economic situation and can help overcome the difficulties in the period of ‘ODA Graduation’

Challenges And Opportunities For The Development Of Infrastructure After ‘Oda Graduation’ - Moving Towards Sustainable Development: Case Study Of Vietnam

The research on ODA will be focused on its relation to Goal 17, the Partnership, considered a major issue by the researchers, especially in the case of Vietnam as a developing economy. ODA was mainly used for investing in economic infrastructure when Vietnam witnessed a downfall in receiving financial aid due to its significant economic growth. ODA helped Vietnam transform from one of the world’s poorest nations into a lower middle-income country and soon, this is going to lead to the ‘ODA Graduation’. However, the process has just begun. The country is still in a process of industrialization and modernization and its socio-economic situation has not been stable or solid. By all means, ODA is not only a financial resource, it also helps the country to accomplish Sustainable Development Goals (SDGs) of the UN. ‘ODA Graduation’ means that the economy of Vietnam has faced certain challenges such as increasing pressure of outbound debts; raising impact on social development or imbalance between high capital recovery investments and public-services investments. However, ‘ODA Graduation’ has brought certain opportunities such as increasing Vietnam’s independence in capital mobilization, preventing the removal of tariffs barrier, reducing losses and waste of funds. This research gives recommendations for improving Vietnam’s economic situation and can help overcome the difficulties in the period of ‘ODA Graduation’

Higgs Mass Constraint on a Low Scale SUSY Model

Randal-Sundrum models have an interesting feature that an effective physical scale can be generated from a much larger one of the underlying theory. In this paper, we investigate a model of supersymmetry in the Randall-Sundrum spacetime with a low cutoff scale. Due to the warp factor, the Kaluza-Klein scale is warped down to $\mathcal{O}$(100) TeV. With the MSSM superfields living in the bulk, the soft SUSY breaking terms of the 4D effective theory are derived from the original 5D Lagrangian by integrating out the extra-dimension. We examine the constraint of the Higgs boson mass measurement on the model. As a result, the viable parameter space with the ability to reproduce a 125 GeV Higgs mass is identified. The constraint rules out parameter regions with the stop masses larger than 20 TeV. Therefore, the parameter space of the model can be explored in a future 100 TeV collider

ESSENTIAL SELF-TRAINING SKILLS TO BECOME AN INTERPRETER: ENGLISH-MAJORING STUDENTS’ PERCEPTION

Currently, interpreting has become a profession in high demand. This study surveyed students' perceptions of the essential self-training skills to become an interpreter. The study used a questionnaire to collect data collection tool which was a survey with 12 multiple-choice questions and 4 open-ended questions. 82 English–majoring students of High-quality program Batch 45 – at Can Tho University participated in the survey. The results show that students majoring in High-quality English Language perceive the importance of skills in interpreting: shorthand skills, listening comprehension skills, memorization skills, visualization skills, presentation skills, skills in using search engines, teamwork skills, multi-tasking skills, and pronunciation skills. Students also pointed out a number of skills that they think are equally important if they want to become an interpreter such as reflexes, situational skills, and contextual skills. On that basis, a number of measures of how to support students to develop their own training plans and hone their skills for their future careers are proposed.  Article visualizations

Effects of protein levels of commercial diets on the growth performance and survival rate of rabbitfish (Siganus guttatus) at the nursing stage

This study aimed to determine the effect of a commercial diet's protein level on the fry-to-fingerling stage. Thirty days-old fries having the initial length and weight of 18.25 ± 0.15 mm fish-1 and 0.036 ± 0.50 g fish-1 respectively have been used in this study. Diet having three protein levels i.e. 30% (trial 1 as control), 35% (trial 2), 40% (trial 3), and 45% (trial 4), respectively, have been used to evaluate the effect of protein, and each trial has been repeated three times. During the study, stocking density was allocated to 1000 fish per composite tank with a volume of 1 m3. After 30 days of rearing, the weight of fingerlings in trial 1 reached up to 1.50 ± 0.02 g fish-1 and it was recorded as 1.52 ± 0.01g for trial 2, these two were lower than that of trials 3 and 4, where fingerling weight was reported 1.69 ± 0.01 and 1.58g fish-1 respectively and obtained the best weight compared to others. The length of fingerlings at the end of the experimental period was also changed in different trials and it was recorded 47.12; 46.92; 50.97; and 48.89 mm fish-1 for trail 1, 2, 3, and 4 respectively, among the tested combinations lower fingerlings length was recorded for trial 2 (35% CP), but it is not significantly different for trial 1 and 2 and a significant difference (P < 0.05) was reported for trail 2, 3, and 4. The survival rate of fingerlings ranged from 67.27 to 72.33%. Meanwhile, the herd distribution coefficient variation (CVW) in the treatment using 40% protein (trial 3) was the highest at 72.33% (p < 0.05). The results of the study can be concluded that the level of protein has a significant effect on the various growth parameters of fingerlings

The Impact of FDI, International Trade, and National Economy on People’s Standard of Living in ASEAN Countries

This research paper analyzes the impact of foreign direct investment (FDI), international trade, and national economy on the standard of living of people in ASEAN member countries, using data from 2012-2021. The study uses data from this period to examine the effects of these variables on the standard of living in ASEAN member countries. The results indicate that international trade and national economy have a significant influence on people's standard of living in the region. However, the effect of FDI varies depending on the level of development of the country. While FDI doesn't have much effect on developing countries, it has a negative impact on developed countries. The study also provides insights for policymakers on how to promote economic growth and improve the quality of life for people in the ASEAN. Keywords: FDI, international trade, national economy, the standard of living, ASEAN DOI: 10.7176/EJBM/15-6-10 Publication date:March 31st 2023

HMU fluorinze mouthwash enhances enamel remineralization: An in vitro study

BACKGROUND: Fluoride therapy has long been used extensively to prevent dental caries. Fluoride appears in variety of dental care products such as mouthrinse, dentifrice, gel, etc. HMU fluorinze is the first mouthwash containing fluoride in Vietnam. AIM: This research was conducted to evaluate the efficacy of HMU Fluorinze mouthwash on remineralizing enamel in laboratory conditions. METHODS: 20 third molars teeth were cleaned and covered with nail polish , except for a 3x3 mm square on their buccal surfaces. These teeth went through two steps: demineralization using Coke and remineralization for 20 days: 1) using standard calcifying solution (control group) and 2) using standard calcifying solution + HMU Fluorinze mouthwash 2 times/day (experimental group). The mineralization index of enamel structure after demineralization and remineralization was assessed by DIAGNOdent pen 2190. RESULTS: The mineralization indexes of the control group and experimental group at baseline were 3.65 ± 0.76 and 3.35 ± 0.64, after demineralization were in turn of 21.78 ± 4.48 and 20.25 ± 2.26; and after remineralization were 6.30 ± 1.03 and 3.90 ± 1.24. The different figures  between the two groups after remineralization shows statistical significance (p<0.01). Group B using HMU fluorinze mouthwash after 20 days did not differ from the original results (p = 0.272), in contrast with the control group (p<0.01). CONCLUSIONS: HMU fluorinze mouthwash has better mineralization effect than standard calcifying solution

The Association Between Ambient Temperatures and Hospital Admissions Due to Respiratory Diseases in the Capital City of Vietnam

This study aimed to examine the short-term effects of ambient temperature on hospital admissions due to respiratory diseases among Hanoi residents. We collected 34,653 hospital admissions for 365 days (November 1, 2017, to November 31, 2018) from two hospitals in Hanoi. A quasi-Poisson regression model with time series analysis was used to explore the temperature-health outcome relationship's overall pattern. The non-linear curve indicated the temperatures with the lowest risk range from 22 degrees (Celcius) to 25 degrees (Celcius). On average, cold temperatures showed a higher risk than hot temperatures across all genders and age groups. Hospital admissions risk was highest at 13 degrees (Celcius) (RR = 1.39; 95% CI = 1.26–1.54) for cold effects and at 33 degrees (Celcius) (RR = 1.21, 95% CI = 1.04–1.39) for the hot effects. Temporal pattern analysis showed that the most effect on respiratory diseases occurred at a lag of 0 days for hot effect and at a lag of 1 day for cold effect. The risk of changing temperature among women and people over 5 years old was higher than other groups. Our results suggest that the risk of respiratory admissions was greatest when the temperature was low. Public health prevention programs should be enhanced to improve public awareness about the health risks of temperature changes, especially respiratory diseases risked by low temperatures