• Title/Summary/Keyword: thermal process

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The effect of heat stress on frame switch splicing of X-box binding protein 1 gene in horse

  • Lee, Hyo Gun;Khummuang, Saichit;Youn, Hyun-Hee;Park, Jeong-Woong;Choi, Jae-Young;Shin, Teak-Soon;Cho, Seong-Keun;Kim, Byeong-Woo;Seo, Jakyeom;Kim, Myunghoo;Park, Tae Sub;Cho, Byung-Wook
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.8
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    • pp.1095-1103
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    • 2019
  • Objective: Among stress responses, the unfolded protein response (UPR) is a well-known mechanism related to endoplasmic reticulum (ER) stress. ER stress is induced by a variety of external and environmental factors such as starvation, ischemia, hypoxia, oxidative stress, and heat stress. Inositol requiring enzyme $1{\alpha}$ ($IRE1{\alpha}$)-X-box protein 1 (XBP1) is the most conserved pathway involved in the UPR and is the main component that mediates $IRE1{\alpha}$ signalling to downstream ER-associated degradation (ERAD)- or UPR-related genes. XBP1 is a transcription factor synthesised via a novel mechanism called 'frame switch splicing', and this process has not yet been studied in the horse XBP1 gene. Therefore, the aim of this study was to confirm the frame switch splicing of horse XBP1 and characterise its dynamics using Thoroughbred muscle cells exposed to heat stress. Methods: Primary horse muscle cells were used to investigate heat stress-induced frame switch splicing of horse XBP1. Frame switch splicing was confirmed by sequencing analysis. XBP1 amino acid sequences and promoter sequences of various species were aligned to confirm the sequence homology and to find conserved cis-acting elements, respectively. The expression of the potential XBP1 downstream genes were analysed by quantitative real-time polymerase chain reaction. Results: We confirmed that splicing of horse XBP1 mRNA was affected by the duration of thermal stress. Twenty-six nucleotides in the mRNA of XBP1 were deleted after heat stress. The protein sequence and the cis-regulatory elements on the promoter of horse XBP1 are highly conserved among the mammals. Induction of putative downstream genes of horse XBP1 was dependent on the duration of heat stress. We confirmed that both the mechanisms of XBP1 frame switch splicing and various binding elements found in downstream gene promoters are highly evolutionarily conserved. Conclusion: The frame switch splicing of horse XBP1 and its dynamics were highly conserved among species. These results facilitate studies of ER-stress in horse.

A Study on the Improvement of Welding Method for Ice Evaporator (얼음증발기 용접방법 개선에 관한 연구)

  • Lee, Jeong-Youn;Yoo, Heung-Ryol;Son, Yung-Deug
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.558-564
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    • 2021
  • The water purifier market has increased rapidly in recent years. The welding technology of the evaporator is a key component that determines the level of ice production and the cold water performance of an ice purifier. The finger type evaporator of an ice purifier can remove ice and is divided largely into an instant heat method and a hot gas method. In the hot gas type evaporator, particularly during the production process, the pinhole phenomenon inside the copper pipe and clogging problems occur intermittently when welding high-pressure pipes due to the high-temperature oxygen welding. Its use in a water purifier can cause a problem in that ice and cold water do not form, and repairs cannot be made on site. To solve this problem, in this study, a cap jig was applied to improve the welding defect of the hot gas evaporator. In addition, the oxygen welding flame size was adjusted so that the heat source could be well supplied to the cap jig, and the effectiveness was confirmed through a wave pressure test, a test, and a thermal shock test.

A Rapid and Simple Detection Assay for Rice Bacterial Leaf Blight by Recombinase Polymerase Amplification (벼 흰잎마름병의 신속하고 간편한 진단을 위한 Recombinase Polymerase Amplification 등온증폭법)

  • Kim, Shinhwa;Lee, Bong Choon;Kim, Hyun Ju;Choi, Soo Yeon;Seo, Su Jwa;Kim, Sang-Min
    • Research in Plant Disease
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    • v.26 no.4
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    • pp.195-201
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    • 2020
  • Rice bacterial leaf blight (BLB) by Xanthomonas oryzae pv. oryzae (Xoo) is considered to be one of the major rice diseases steadily occurring around the rice-producing countries. In this study, we developed a recombinase polymerase amplification (RPA) assay for the rapid, convenient and specific diagnosis of Xoo by targeting Xoo-specific transposase A gene. As the target gene can be amplified in 10 min without DNA extraction process and special equipment for temperature control, RPA for BLB can be useful and practical component for on-site diagnosis.

Carbon Capture and CO2/CH4 Separation Technique Using Porous Carbon Materials (다공성 탄소재료를 이용한 CO2 포집 및 CO2/CH4 분리 기술)

  • Cho, Se Ho;Bai, Byong Chol;Yu, Hye-Ryeon;Lee, Young-Seak
    • Applied Chemistry for Engineering
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    • v.22 no.4
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    • pp.343-347
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    • 2011
  • Due to the strong dependence on fossil fuels within the history of human progress, it leads to disaster of the whole world like flood, shortage of water and extinction of the species. In order to curb carbon dioxide emissions, many technologies are being developed. Among them, porous carbon materials have important advantages over other absorbent, such as high surface area, thermal and chemical resistance, low cost, various pore distribution and low energy requirement for their regeneration. Carbon capture and storage (CCS) has attracted the significant research efforts for reducing green house gas emission using several absorbent and process. Moreover, the absorbent are used for the separation of bio mass gas that contains methane which is considered a promising fuel as new green energy resource. In this review, we summarized the recent studies and trend about the porous carbon materials for CCS as well as separation from the biogas.

Current Status of X-ray CT Based Non Destructive Characterization of Bentonite as an Engineered Barrier Material (공학적방벽재로서 벤토나이트 거동의 X선 단층촬영 기반 비파괴 특성화 현황)

  • Diaz, Melvin B.;Kim, Joo Yeon;Kim, Kwang Yeom;Lee, Changsoo;Kim, Jin-Seop
    • Tunnel and Underground Space
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    • v.31 no.6
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    • pp.400-414
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    • 2021
  • Under high-level radioactive waste repository conditions, bentonite as an engineered barrier material undergoes thermal, hydrological, mechanical, and chemical processes. We report the applications of X-ray Computed Tomography (CT) imaging technique on the characterization and analysis of bentonite over the past decade to provide a reference of the utilization of this technique and the recent research trends. This overview of the X-ray CT technique applications includes the characterization of the bentonite either in pellets or powder form. X-ray imaging has provided a means to extract grain information at the microscale and identify crack networks responsible for the pellets' heterogeneity. Regarding samples of pellets-powder mixtures under hydration, X-ray CT allowed the identification and monitoring of heterogeneous zones throughout the test. Some results showed how zones with pellets only swell faster compared to others composed of pellets and powder. Moreover, the behavior of fissures between grains and bentonite matrix was observed to change under drying and hydrating conditions, tending to close during the former and open during the latter. The development of specializing software has allowed obtaining strain fields from a sequence of images. In more recent works, X-ray CT technique has served to estimate the dry density, water content, and particle displacement at different testing times. Also, when temperature was added to the hydration process of a sample, CT technology offered a way to observe localized and global density changes over time.

Delamination Prediction of Semiconductor Packages through Finite Element Analysis Reflecting Moisture Absorption and Desorption according to the Temperature and Relative Humidity (유한요소 해석을 통해 온도와 상대습도에 따른 수분 흡습 및 탈습을 반영한 반도체 패키지 구조의 박리 예측)

  • Um, Hui-Jin;Hwang, Yeon-Taek;Kim, Hak-sung
    • Journal of the Microelectronics and Packaging Society
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    • v.29 no.3
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    • pp.37-42
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    • 2022
  • Recently, the semiconductor package structures are becoming thinner and more complex. As the thickness decrease, interfacial delamination due to material mismatch can be further maximized, so the reliability of interface is a critical issue in industry field. Especially, the polymers, which are widely used in semiconductor packaging, are significantly affected by the temperature and moisture. Therefore, in this study, the delamination prediction at the interface of package structure was performed through finite element analysis considering the moisture absorption and desorption under the various temperature conditions. The material properties such as diffusivity and saturated moisture content were obtained from moisture absorption test. The hygro-swelling coefficients of each material were analyzed through TMA and TGA after the moisture absorption. The micro-shear test was conducted to evaluate the adhesion strength of each interface at various temperatures considering the moisture effect. The finite element analysis of interfacial delamination was performed that considers both deformation due to temperature and moisture absorption. Consequently, the interfacial delamination was successfully predicted in consideration of the in-situ moisture desorption and temperature behavior during the reflow process.

New Yellow Quinoline Derivatives Including Dione Moiety for Image Sensor Color Filters (이미지 센서 컬러 필터용 다이온 성분을 포함하는 신규 황색 퀴놀린 유도체)

  • Sunwoo, Park;Seyoung, Oh;Yuna, Kang;Hyukmin, Kwon;Sunwoo, Dae;Changyu, Lee;Dae Won, Kim;Min-Sik, Jang;Jongwook, Park
    • Applied Chemistry for Engineering
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    • v.34 no.1
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    • pp.80-85
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    • 2023
  • New yellow quinoline-dione dye derivatives were designed and synthesized for use in image sensor color filters. The synthesized compounds have a basic chemical structure composed of quinoline and dione groups. New materials were evaluated on the basis of their optical and thermal properties under conditions mimicking those of a commercial device fabrication process. A comparison of their related performances revealed that, between the two prepared compounds, 2-(3-hydroxyquinolin-2(1H)-ylidene)-1H-indene-1,3(2H)-dione (HQIDO) exhibited the superior performance as an image sensor color filter material, including a solubility greater than 0.5 wt% in propylene glycol monomethyl ether acetate solvent and a high decomposition temperature of 298 ℃, respectively. The results suggest that HQIDO can be used as a yellow dye additive in an image sensor colorant.

Improving Lifetime Prediction Modeling for SiON Dielectric nMOSFETs with Time-Dependent Dielectric Breakdown Degradation (SiON 절연층 nMOSFET의 Time Dependent Dielectric Breakdown 열화 수명 예측 모델링 개선)

  • Yeohyeok Yun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.16 no.4
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    • pp.173-179
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    • 2023
  • This paper analyzes the time-dependent dielectric breakdown(TDDB) degradation mechanism for each stress region of Peri devices manufactured by 4th generation VNAND process, and presents a complementary lifetime prediction model that improves speed and accuracy in a wider reliability evaluation region compared to the conventional model presented. SiON dielectric nMOSFETs were measured 10 times each under 5 constant voltage stress(CVS) conditions. The analysis of stress-induced leakage current(SILC) confirmed the significance of the field-based degradation mechanism in the low electric field region and the current-based degradation mechanism in the high field region. Time-to-failure(TF) was extracted from Weibull distribution to ascertain the lifetime prediction limitations of the conventional E-model and 1/E-model, and a parallel complementary model including both electric field and current based degradation mechanisms was proposed by extracting and combining the thermal bond breakage rate constant(k) of each model. Finally, when predicting the lifetime of the measured TDDB data, the proposed complementary model predicts lifetime faster and more accurately, even in the wider electric field region, compared to the conventional E-model and 1/E-model.

Titanium Isopropoxide (TTIP) Treatment Strategy for V2O5-WO3/TiO2 SCR Catalysts with a Wide Operating Temperature (넓은 작동 온도범위를 가지는 V2O5-WO3/TiO2 SCR 촉매 개발을 위한 티타늄 이소프로폭사이드(TTIP) 활용 전략)

  • Jaeho Lee;Gwang-hun Cho;Geumyeon Lee;Changyong Yim;Young-Sei Lee;Taewook Kim
    • Applied Chemistry for Engineering
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    • v.34 no.4
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    • pp.357-364
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    • 2023
  • Selective catalytic reduction (SCR) is the most effective method for reducing nitrogen oxide emissions, but the operating temperature range of V2O5-WO3/TiO2 catalysts is narrow (300~400℃). In this study, a new catalyst with an operating temperature range of 200~450℃ was developed. The catalyst poison, ammonium bisulfate, generated during the SCR process can be removed by heating above 350℃. To increase the number of active sites and promote the dispersion of active materials, titanium isopropoxide (TTIP) treatment was performed on the TiO2 support with various TTIP/TiO2 mass ratios. Among them, the 5 wt% TTIP loaded catalyst showed improved performance due to higher thermal stability caused by high W dispersion and the formation of V5+. In addition, the 5 wt% TTIP-loaded catalyst prepared by a one-step co-precipitation method showed greater V-OH and W-OH dispersion and enhanced interactions in contrast to conventional methods, resulting in higher catalytic activity at lower temperatures. This review article aims to provide an accessible explanation for researchers investigating how to improve the surface properties of TiO2 catalysts using TTIP.

A Relation of Urbanization Entropy and Urban Heat Phenomenon (도시화 엔트로피와 도시 열현상과의 관계성)

  • Sangjun Kang
    • Journal of the Korean Regional Science Association
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    • v.39 no.3
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    • pp.3-12
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    • 2023
  • The issue to be discussed is set as the relationship between urban fragmentation and urban heat phenomena. The fragmentation is recognized as a negative form that commonly occurs in the process of urbanization. The purpose of this study is to examine the relationship between urbanization entropy and heat phenomenon by looking at the five major cities in Korea. The employed methods are InVEST Urban Cooling Model and MSPA (Morphological Spatial Pattern Analysis) by using the meteological data for the July 2018. The major results are as follows; First, a low rank correlation(rho=-0.3) is found in the relation between entropy and Cooling Capacity Index (CCi). Second, a very high level of rank correlation is observed between entropy and Average Temperature(℃)(rho=0.9). The implications are that 1) a city with a large degree of sprawling development can have a negative effect on urban heat phenomena; 2) the composition of land use including dispersion and concentration in non-urbanized areas, which has the characteristics of open space, can affect the urban thermal environment. Due to the limited number of case studies, it is appropriate to understand that a possibility, not generalization, is observed between entropy and heat phenomena in urbanized areas.