Fabrication and characterization of aluminum-doped zinc oxide Schottky diodes on n-GaN

T. Han,Y. Shi,H. Wu,C. Liu 한국물리학회 2012 Current Applied Physics Vol.12 No.6

Aluminum-doped zinc oxide (AZO) films were prepared using an electron-beam evaporation system to form Schottky contacts on n-type GaN at depositing temperatures varied from 100 to 400 ℃. The currentevoltage (I-V) measurements which showed a rectifying characteristic were carried out to deduce the Schottky barrier heights (SBHs) according to the thermionic emission theory. The SBHs were calculated by using a linear curve fit to forward characteristics of ln(I) against V, and have a small alteration around 0.7 eV. Hall-effect measurements were carried out to illuminate the alteration of the SBHs that were mainly affected by the carrier concentration of the AZO films. It has been found that the SBH ascends as the carrier concentration decrease, and the dislocations play an important role on the leakage current of the contacts.

Low Resistance and Transparent Ag/AZO Ohmic Contact to p-GaN

T. Han,T. Wang,X. W. Gan,H. Wu,Y. Shi,C. Liu 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.1

Silver (Ag)/ aluminum-doped zinc oxide (AZO) films were deposited on p-GaN by using electronbeamevaporation. After the annealing process, current -voltage (I-V) measurements were carriedout to determine the characteristic of the contacts. The Ag/AZO films annealed at 600 C werefound to present an ohmic contact behavior. The specific contact resistance was calculated tobe 9.76 × 10−4cm2 and the transmittance was over 80% for visibly light. The atomic forcemicroscope was used to measure the aggregation of Ag grains which may have been the main factorin the formation of the Ag/AZO ohmic contact to p-GaN.

Characterizing Helicobacter pylori cagA in Myanmar

( Thein Myint ),( Muhammad Miftahussurur ),( Ratha-korn Vilaichone ),( New Ni ),( Than Than Aye ),( Phawinee Subsomwong ),( Tomohisa Uchida ),( Varocha Mahachai ),( Yoshio Yamaoka ) 대한간학회 2018 Gut and Liver Vol.12 No.1

Background/Aims: Differences in the Helicobacter pylori infection rate are not sufficient to clarify the dissimilarity of gastric cancer incidence between Myanmar and its neighboring countries. To better understand this trend, the H. pylori virulence gene cagA was characterized in Myanmar. Methods: Glutamate-proline-isoleucine-tyrosine-alanine (EPIYA) patterns and CagA multimerization (CM) motifs of cagA genotypes were examined by performing polymerase chain reactions and DNA sequencing. Results: Of 69 tested H. pylori strains, cagA-positive patients had significantly more severe histological scores in their antrum than cagA-negative patients. Sequence analysis revealed that 94.1% of strains had Western-type cagA containing an EPIYA motif (92.6%) or EPIYT motif (6.4%). The intestinal metaplasia scores in the antral of patients infected with the ABC and ABCC types of cagA were significantly higher than those of patients with AB-type cagA. Interestingly, in patients infected with H. pylori, 46.3% of strains with three EPIYA motifs contained two identical Western-typical CM motifs, and these patients showed significantly higher antrum inflammation scores than patients infected with two identical nontypical-CM motif strains (p=0.02). Conclusions: In Myanmarese strains, Western-type cagA was predominant. The presence of CM motifs and the proportion of multiple EPIYA-C segments might partially explain the intermediate gastric cancer risk found in Myanmar. (Gut Liver 2018;12:51-57)

Bio assay of DNP 7, 9 Response in Rice Screening with Whitebacked planthopper

Sopheap Yun,Vicheka Than,Kyung-A kim,Hyun-Suk Lee,Gi-Hwan Yi,Byung-Wook Yun,Kyung-Min Kim 한국육종학회 2015 한국육종학회 심포지엄 Vol.2015 No.07

The objectives of this study were to investigate the diversity of natural products (DNP7, 9) in responding to Whitebacked planthopper (WBPH) feeding. Resistant rice (cv. Cheongcheong ), susceptible rice (cv. Nagdong) and susceptible control rice (cv. TN1) were used as materials for WBPH infestation in seedling stage. The treatment was conducted by spraying DNP 7 and 9 for 100 ppm to materials before being fed to 2nd and 3rd instar WBPH while control group was not sprayed DNP 7 and 9. The density of WBPH was 7 insect per plant. As a result, WBPH survival rate of 57% was found in the DNP 7 treatment, whereas those in DNP 9 and control were 27% and 71%, respectively. Resistance score of Cheongcheong, Nagdong, and TN1 in DNP 7 treatment were 3.4±0.8, 5.9±1.9, and 6.8±1.6, respectively, while those in DNP 9 treatment were 1.6±0.8, 4.7±1.6, and 7.9 ±1.4, respectively. The plant heights of Cheongcheong, Nagdong, and TN1 in DNP 7 treatment after 3 week infestation were 19.7±3.0, 23.4±7.5, and 15.8±8, respectively while those in DNP 9 treatment were 32.4±4, 26.3±12.7, and 25.9±8.5, respectively. Moreover, chlorophyll content was examined 3 week post infestation. In both DNP 7 and DNP 9 treatment, the chlorophyll levels of Cheongcheong and Nagdong in were higher than that in control. Based on observation and bio-scoring, plant with DNP 9 was strongly resistant to WBPH feeding and the survival rate of WHPB was lower than plant with DNP7.

Impact of Community Attachment and Resident's Support on Destination Sustainability: Evidence from Spiritual and Community Destination in Vietnam

THAN, Trong Thuy,KIEU, Thi Phuong Hoa,PHAM, Thi Anh Duong,HOANG, Thi Cam Van,TRAN, Thi Hau,NGUYEN, Huu Doan,DAO, Trung Kien Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.8

This study investigates the influence of community involvement on the destination sustainability for community destinations and spiritual destinations in Vietnam. Community involvement is measured by two constructs, which are community attachment and residents' support. A structural questionnaire consisting of 41 observation variables measured on a 5-point Likert scale was used to survey households who live in a spiritual destination in An Giang province and three community destinations in Lang Son province with the help of local tour guides and Youth Union. 168 out of 200 responses collected were valid for multivariate data analysis. The results of confirmatory factor analysis (CFA) and structural equation modeling (SEM) reveal three main findings. Firstly, community attachment has a direct effect on both perceived benefits and destination sustainability. Secondly, while residents' support has a direct effect on perceived benefits, it indirectly affects destination sustainability. Finally, community destinations have a higher level of sustainability than the spiritual destination. Based on those findings, this study proposed three suggestions for local authorities, policymakers, and residents to improve the sustainable development of their local tourism destinations, including (1) diversifying local tourism products, (2) encouraging the community participation in tourism development programs, and (3) increasing in the expected benefits in local tourism development policies.

Integrated approach for rotor blade manufacturing cost estimate

Lin, Than,Lee, Jae-Woo,Lwin, Tun Emerald Group Publishing Limited 2011 Aircraft engineering and aerospace technology Vol.83 No.4

<B>Purpose</B> - The purpose of this research is to develop an integrated model for composite rotor blade manufacturing cost estimates at the conceptual design stage. The integrated model seeks to provide a rapid and dynamic feedback based on evaluating the manufacturing cost estimate for a new product design at the conceptual design stage. This paper describes the automated estimating process for design to manufacturing cost of composite rotor blade. <B>Design/methodology/approach</B> - An integrated approach is implemented for evaluating the manufacturing cost estimates. The paper develops each module of the computer-aided parametric model generation, time estimation models for composite manufacturing processes and decision support system. Finally, process flow data integration is done for all the modules. An example for a complicated geometric rotor blade is shown in this research paper. The results are compared in different design parameters and discussed. <B>Findings</B> - The data integration for this approach was built by using ModelCenter<SUP>®</SUP> software. It is easier and more robust to apply than the other proposed methods. The selection of design, material and manufacturing parameters is achieved by integrated model within a short period of time. <B>Practical implications</B> - This paper provides an integrated concurrent approach for manufacturing cost evaluation of composite rotor blade. Manufacturing factors could be considered at the early stage of product development phase. <B>Originality/value</B> - This paper suggests an effective and efficient way of evaluating the manufacturing cost at the conceptual stage of the design process. The concurrent engineering and integrated product process development approaches were addressed.

Determinants of Success of University Students in Vietnam: An Empirical Study

NGUYEN, Lan T.N.,THAN, Thao T.,NGUYEN, Tan G. Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.10

This paper investigates the determinants of students' success in Vietnam through conducting online interviews and surveys with 2,500 Vietnamese students at eight famous universities in Vietnam. By applying both SPSS 22 and STATA software, the study is to evaluate the impact of four driver factors, which affect GPA, language efficacy, and personal achievement. These factors are psychological perspective, home environmental, student demographic, and school environmental. The research results emphasize a positive effect of psychological and home-environmental determinants, but the negative effect of school environmental factors on the students' success. Besides, the relationship between demographics and student success was tested and indicated that male students have a better language learning ability, but a low level of academic achievement than female students. The results also point out the impact of religious affiliation and ethnicity on personal achievement. Non-religious students are better achievers than those having a religion or those in minority ethnicity. Moreover, accumulated schooling years are negatively associated with students' success. The more working experience students accrued, the higher possibility they are successful. Finally, the finding provides an insight into students' success that might be useful to government authorities and other universities in designing policies for enhancing the quality of education.

New method to stimulate the onset of Bombus terrestris (Hymenoptera: Apidae) rearing: Using worker helpers in the presence of frozen pupae

권용정,Kyi Kyi THAN,서상재 한국곤충학회 2006 Entomological Research Vol.36 No.4

The failure of bumblebee queens to enthusiastically start a colony under laboratory conditions may be due to lack of oviposition during an experiment, a long delay in oviposition from the termination of hibernation, and failure to rear a large first brood. In the present study, the use of frozen male pupae to start the colony with the assistance of bumblebee workers rather than fresh, young, male pupae was investigated under controlled room temperature and humidity conditions. The period of initiation of the colony decreased with an increase in the number of worker helpers from one to six. The period was as short as 3.9 days in the presence of six worker helpers. Second and third broods also started earlier with the help of workers. The rate of first worker production per egg cup was double that of the normal method (i.e. without worker helpers). Egg eating behavior of the queen was not found in the first brood if more than two workers helped the development of the larvae. Four worker helpers were found to be sufficient, as they could produce 100% colony foundation and 91.46% first worker production colonies. This study showed that using frozen old pupae is a good stimulator for colony foundation in the presence of four bumblebee worker helpers.

인공어초 저속 흐름 영역의 정량화 기법

반 탄 차우(Van-Than Chau),나원배(Won-Bae Na) 한국해양환경·에너지학회 2021 한국해양환경·에너지학회 학술대회논문집 Vol.2021 No.10

3차원 유한체적법을 사용하여 3가지 유형(관형, 구형, 사각형)으로 분류된 인공어초의 저속 흐름영역을 조사하였다. 이를 위해 적절한 유동장과 격자 크기를 결정하기 위한 독립성 시험을 수행하였다. 인공어초의 저속 흐름 영역을 추정하여 기존의 인공어초보다 37% 더 많은 저속 흐름 영역을 갖는 관형 어초를 발견하였다. 저속 흐름 영역을 추정하는 방정식이 적용되었으며 이로부터 인공어초의 흐름 특성을 정량화하는 인공어초 용량 지수가 제안되었다. Low-velocity flow regions of three types of artificial reefs (ARs), including tube, ball, and cube-AR, were investigated by the 3D finite volume method. An independent test was conducted to determine a suitable domain and mesh size. Low-velocity flow regions of three ARs were estimated, and accordingly an optimal cube AR was found with 37% capacity higher than the original cube AR. An estimated equation was applied for quantifying the low-velocity flow regions, and a new parameter, artificial reef capacity, was proposed to classify ARs by low-velocity region volume.

Effect of cytochrome P450 3A5 polymorphism on the pharmacokinetics of tacrolimus in renal transplant recipients

Yi Yi Htun,Nwe Nwe Than,Htar Kyi Swe 대한이식학회 2020 Korean Journal of Transplantation Vol.34 No.1

Background: Renal transplant is an effective treatment option for end-stage kidney disease and tacrolimus is one of the most commonly used immunosuppressant drugs in renal transplant patients. Tacrolimus is a substrate of cytochrome P450 3A5 (CYP3A5), and a narrow therapeutic index and large inter-individual variability. The objective of this study was to determine the frequency of CYP3A5*3 polymorphism and its effect on the pharmacokinetics of tacrolimus in post-renal transplant patients at Mandalay General Hospital. Methods: Three different genotypes of CYP3A5 were determined by polymerase chain reaction-restriction fragment length polymorphism in 54 post-renal transplant recipients. Tacrolimus trough concentrations (Ctrough) were measured by enzyme multiplied immunoassay technique following method validation. The apparent clearance (CL/F) was calculated from measured Ctrough. Results: The frequency of CYP3A5*1 allele was 0.24 and that of CYP3A5*3 allele was 0.76 in the study sample. There were a total of 33 CYP3A5 non-expressors (patients with CYP3A5*3/*3 genotype) and 21 CYP3A5 expressors (patients with CYP3A5*1/*1 or CYP3A5*1/*3 genotype), respectively. CL/F was significantly lower in the non-expressor group than in the expressor group (mean±standard deviation, 12.53±5.28 vs. 21.22±5.95 L/hr; P<0.001). The mean Ctrough and concentration dose ratio (C/D) for tacrolimus in CYP3A5 non-expressors were significantly higher than those in CYP3A5 expressors (Ctrough, 7.14±2.56 vs. 5.92±1.76 ng/mL; C/D, 6.92±4.11 vs. 2.89±1.85 ng/mL/mg), respectively (P<0.05). Conclusions: In this study, 76% of the Myanmar renal transplant recipients carried the CYP3A5*3 allele that was associated with lower functional activity of the CYP3A5 enzyme a lower CL/F of tacrolimus in these Thus, CYP3A5 polymorphism influences the pharmacokinetics of tacrolimus, which may affect the pharmacological response to tacrolimus.