Composition, Structural, and Electrical Investigations on DC-Magnetron-Sputtered TiO2 Thin Films

An Myung-Hwan 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.47 No.3

Amorphous thin films of titanium dioxide (TiO2) with perfect stoichiometry were deposited onto well-cleaned p-type silicon (p-Si) substrates by using DC magnetron sputtering. The thicknesses of the films were measured using an alpha step profilometer. The composition of the films were analyzed using Auger electron spectroscopy (AES), and the films were found to be stoichiometric (O/Ti = 2.08). From the atomic force microscope (AFM) analysis, the surface morphology, the root-mean-square roughness (Rrms), and the average roughness (Rs) were determined. The influence of post-deposition annealing at 673 and 773 K on the composition and on the structural and the electrical properties was studied. The thicknesses of the films were found to be more or less the same irrespective of the annealing temperature and time. X-ray diffraction (XRD) results revealed the amorphous nature of the as-deposited films while the annealed films were found to be crystalline with a tetragonal symmetry. The lattice constants, the grain size, the microstrain, and the dislocation density of the film were calculated and correlated with the annealing temperature. The capacitance-voltage (C-V) characteristics of the Al/TiO2/Si structure were measured using standard techniques, and the dynamic dielectric constants, the flat-band voltages, and the flat-band capacitances of the as-deposited and the annealed samples were evaluated and reported.

딥러닝 알고리즘을 이용한 토마토에서 발생하는 여러가지 병해충의 탐지와 식별에 대한 웹응용 플렛폼의 구축

나명환 ( Na¸ Myung Hwan ),조완현 ( Cho¸ Wanhyun ),김상균 ( Kim¸ Sangkyoon ) 한국품질경영학회 2020 품질경영학회지 Vol.48 No.4

Purpose: purpose of this study was to propose the web application platform which can be to detect and discriminate various diseases and pest of tomato plant based on the large amount of disease image data observed in the facility or the open field. Methods: The deep learning algorithms uesed at the web applivation platform are consisted as the combining form of Faster R-CNN with the pre-trained convolution neural network (CNN) models such as SSD_mobilenet v1, Inception v2, Resnet50 and Resnet101 models. To evaluate the superiority of the newly proposed web application platform, we collected 850 images of four diseases such as Bacterial cankers, Late blight, Leaf miners, and Powdery mildew that occur the most frequent in tomato plants. Of these, 750 were used to learn the algorithm, and the remaining 100 images were used to evaluate the algorithm. Results: From the experiments, the deep learning algorithm combining Faster R-CNN with SSD_mobilnet v1, Inception v2, Resnet50, and Restnet101 showed detection accuracy of 31.0%, 87.7%, 84.4%, and 90.8% respectively. Finally, we constructed a web application platform that can detect and discriminate various tomato deseases using best deep learning algorithm. If farmers uploaded image captured by their digital cameras such as smart phone camera or DSLR (Digital Single Lens Reflex) camera, then they can receive an information for detection, identification and disease control about captured tomato disease through the proposed web application platform. Conclusion: Incheon Port needs to act actively paying

Effects of Air Gap on HTS Magnet Consisting of Double Pancake Windings

Myunghwan Ku,Myunghun Kang,Youngmin Kim,Heejoon Lee,Gueesoo Cha 한국초전도저온학회 (구 한국초전도저온공학회) 2009 한국초전도저온공학회논문지 Vol.11 No.4

Comparison of different crate material types for transit on meat quality and blood metabolites of broilers during the summer season

Myunghwan Yu,Elijah Ogola Oketch,Jun Seon Hong,Haeeun Park,Jung Min Heo 한국가금학회 2022 한국가금학회 정기총회 및 학술발표회 Vol.2022 No.11

Broiler responses to dietary 3,4,5-trihydroxybenzoic acid and oregano extracts under Eimeria challenge conditions

( Myunghwan Yu ),( Jong Oh Jeon ),( Hyun Min Cho ),( Jun Seon Hong ),( Yu Bin Kim ),( Shan Randima Nawarathne ),( Samiru Sudharaka Wickramasuriya ),( Young-joo Yi ),( Hans Lee ),( Vannie Wan ),( Noele 한국축산학회 2021 한국축산학회지 Vol.63 No.6

This study was conducted to evaluate the efficacy of a combination 3,4,5-trihydroxybenzoic acid (THB) and oregano extracts (i.e., Carvacrol and Thymol) at intake/dietary different levels on growth performance, intestinal health indicators, immune responses and fecal oocyst shedding in broiler chickens under Eimeria challenged condition. A total of 336 one-day-old broilers were randomly assigned to one of six dietary treatments with seven replications per treatment. Dietary treatments were: i) Non-challenged bird without any dietary treatment (NCNT), ii) Challenged bird without any dietary treatment (CNT), iii) Challenged birds fed a THB diet (0.1 g/kg, THB), iv) Challenged birds fed a combination of THB and oregano extracts diet (0.1 g/kg, COM 100), and a gradual increase of combination of THB and oregano extracts likely v) 0.15 g/kg (COM 150), and 0.2 g/kg (COM 200). On day 14, all groups except for NCNT have orally challenged with a 10-fold dose of Livacox® T anticoccidial vaccine to trigger coccidiosis. The results indicated that Eimeria-challenged broilers fed COM 100 and COM 200 diets increased (p < 0.05) body weight than CNT diet on day 35. Furthermore, birds fed COM 100 and COM 200 diets increased (p < 0.05) average daily gain compared to those fed CNT diets for the entire experimental period. There is no significant (p > 0.05) in average daily feed intake, feed efficiency between NCNT and birds fed with combined THB and oregano extracts for the entire experimental period. A combination of THB and oregano extract regardless of concentration levels or THB alone reduced (p < 0.05) lesion score in ileum compared to the CNT diet for 7 days post-infection (dpi). Birds fed COM 100 diet had lower (p < 0.05) intestinal lesion scores in jejunum and caeca on 7 dpi compared to those were in the CNT diet. No (p > 0.05) difference was observed in the oocysts per gram of feces count, intestinal morphology, carcass traits and blood cytokine concentration among the infected treatments. Collectively, we conclude that birds fed with a combination of THB and oregano extracts regardless of the ratios that were used demonstrated better recovery of health after the coccidial challenge than using only THB alone.

Effect of crating density in transit on carcass traits and meat quality of broilers

Myunghwan Yu,Jun Seon Hong,Yu Bin Kim,Shan Randima Nawarathne,Oketch Elijah Ogola,Jung Min Heo 한국가금학회 2021 한국가금학회 정기총회 및 학술발표회 Vol.2021 No.11

A comprehensive overview of coccidiosis in chicken

( Myunghwan Yu ),( Jung Min Heo ) 한국축산학회 2021 축산기술과 산업 Vol.8 No.2

Coccidiosis is the main parasitic disease resulting from the intracellular protozoan that targets each different part of the intestinal tract leading to destroy in poultry. For this reason, coccidiosis induces an enormous economic loss in the poultry industry. Eimeria life cycle is complicated and comprised of exogenous and endogenous stages inducing an inflammatory response which results in enteric damage associated with diarrheal hemorrhage, disorder digestion of feed and nutrient absorption, dehydration, blood loss, mortality. Hence, it is very important to understand the information of Eimeria parasites for elimination and treatment. This disease has been controlled by various anticoccidial drugs and vaccines as the most common management practices. However, not only the occurrence of drug resistance due to anticoccidial drugs but lack of a guarantee of safety with vaccine use, has led to the development of alternative strategies to control coccidiosis. For these reasons, phytogenic compounds are emerging for the control and prevention of poultry coccidiosis to alternate previous methods. The main aim of this review is to provide an overview of coccidiosis including etiology, morphology, life cycle, pathogenicity, clinical sign, diagnosis, control and prevention.

Comprehensive functional screening of taste sensation in vivo

Myunghwan Choi 한국실험동물학회 2020 한국실험동물학회 학술발표대회 논문집 Vol.2020 No.2

Nanoscale optical imaging on live myelinated axons

Myunghwan CHOI 한국생물공학회 2018 한국생물공학회 학술대회 Vol.2018 No.4

Enhanced intracellular survival of Brucella abortus in RAW 264.7 cells by mutagenesis at BruAb2_1031

( Myunghwan Jung ),( Soo Jin Shim ),( Young Bin Im ),( Woo Bin Park ),( Hansang Yoo ) 대한인수공통전염병학회 2016 창립총회 및 학술대회 초록집 Vol.2016 No.1

Introduction: Brucella abortus(B. abortus) , known as intracellular bacteria, can invade and replicate in professional and nonprofessional phagocytic cells. Pathogenesis of B. abortus is more related to strategies for intracellular survival such as modulation of normal host functions than production of classical virulence factors such as exotoxin, cytolysins, capsules, fimbria, plasmids, lysogenic phage, and endotoxic lipopolysaccharide (LPS) molecules. Therefore, identification of the intracellular survival strategies of B. abortus is important in a study on pathogenicity of brucellosis. As the first step to find out the intracellular survival strategies, functions of Brucella genes were analyzed using transposon mutagenesis based on differences in the transcriptional responses between macrophages infected with the B. abortus mutant strains and the B. abortus wild strain. Materials and methods: Mutant strains derived from B. abortus 1119-3 strain, C3, C24, and C30, were generated by Tn5 transposome complexes.Identification of transposon insertion site was conducted using randomly primed PCR and Southern blot. Macrophages were infected with B. abortus wild and mutant strains of MOI 10. Total RNA was extracted from the cells at 0, 12, 24 h after infection using RNeasy mini kit as described by the manufacturers. Following purity and integrity check, RNA samples were subjected to microarray hybridization. The results of microarray were validated using quantitative real-time PCR. The genes showing change of expression level were analyzed based on the pathway, gene networks, and biological process. Gentamicin assay was also carried out using RAW 264.7 cells infected with each strain at MOI 100 to demonstrate levels of internalization, intracellular survival, and replication in RAW 264.7 cells. Results: The single insertion of transposon was confirmed by randomly primed PCR and Southern blot in the mutant strains. Following infection, wild strain infected RAW 264.7 cells showed up-regulated inflammatory responses and down-regulated phagolysosome formation process. The genes involved in apoptosis showed both up- and down-regulation. When compared to the transcriptional responses of wild strain infected cells, down-regulation of genes associated with cytokine responses and apoptosis was observed in RAW 264.7 cells infected with C3 mutant strain, in which mutation was confirmed at the site of the ATP-binding cassette transporter permease (BruAb2_1031). However, RAW 264.7 cells infected with C24 and C30 mutant strains did not show notable differences when compared to the wild strain infected cells. Although B. abortus wild strain showed high level of internalization, a steep decrease in CFU number of intracellular brucellae was observed in wild strain infected RAW 264.7 cells when compared to C3 mutant (p< 0.01). In real-time PCR to verify the microarray results, all genes determined by PCR showed the same direction in expression levels as the microarray results. Conclusion: C3 mutant strain infected RAW 264.7 cells showed down-regulation in genes associated with protective immune responses to Brucella infection. This result suggested that C3 mutant strain has more enhanced strategies for intracellular survival than the wild strain. Therefore, it is plausible that transposon insertion at BruAb2_1031 of Brucella abortus could enhance the intracellular survival in RAW 264.7 cells. Acknowledgements: This work was supported by NRF grant funded by MSIP (No. 2014R1A2A2A01007291), Bk21 PLUS and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea.