• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.133-136
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• 2007

It has been applied the self adhesion waterproofing sheet which is developed from exist asphalt waterproofing sheet by heat and torch in domestic construction field. However, the problem of waterproofing have constantly happened due to air pocket condition and defect of joint part in waterproofing construction. Therefore, in this study, we would like to analyze the field application as testing in side of materials and construction method of self adhesion butyl rubber sheet and study of the materials performance.

• Macromolecular Research
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• v.10 no.3
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• pp.168-173
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• 2002

Unstabilized low-density polyethylene (LDPE) films and films formulated with hindered amine light stabilizer (HALS) were exposed to UV-radiation; and the physicochemical changes during photooxidation processes have been investigated using tensile, FTIR spectre-photometric and thermal analytical (DSC) techniques. The dependence of tensile properties (elongation- and stress-at-break), carboxyl index and heat of fusion on UV-irradiation time have been discussed. The use of HALS is found to be effective in maintaining the UV-mechanical properties of the LDPE films. The experimental results showed that there exists no correlation between mechanical properties and carbonyl index, whereas crystallinity correlates well with carbonyl index in unstabilized and stabilized films for irradiation times greater than 100 h. The rate of formation of carbonyl groups is found to be dependent on UV exposure time. Crystallinity of the film samples is strongly influenced by both exposure time and presence of HALS.

• Structural Engineering and Mechanics
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• v.32 no.3
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• pp.429-445
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• 2009

Thermal stability of quasi-isotropic composite and polymeric structures is considered one of the most important criteria in predicting life span of building structures. The outdoor applications of these structures have raised some legitimate concerns about their durability including moisture resistance and thermal stability. Exposure of such quasi-isotropic composite/polymeric structures to various and severe climatic conditions such as heat flux and frigid climate would change the material behavior and thermal viability and may lead to the degradation of material properties and building durability. This paper presents an analytical model for the generalized problem. This model accommodates the non-linearity and the non-homogeneity of the internal heat generated within the structure and the changes, modification to the material constants, and the structural size. The paper also investigates the effect of the incorporation of the temperature and/or material constant sensitive internal heat generation with four encountered climatic conditions on thermal stability of infinite cylindrical quasi-isotropic composite/polymeric structures. This can eventually result in the failure of such structures. Detailed critical analyses for four case studies which consider the population of the internal heat generation, cylindrical size, material constants, and four different climatic conditions are carried out. For each case of the proposed boundary conditions, the critical thermal stability parameter is determined. The results of this paper indicate that the thermal stability parameter is critically dependent on the cylinder size, material constants/selection, the convective heat transfer coefficient, subjected heat flux and other constants accrued from the structure environment.

• Mass Spectrometry Letters
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• v.7 no.1
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• pp.1-11
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• 2016

Various efforts have been developed to improve sample preparation steps, which strongly depend on hands-on processes for accurate and sensitive quantitative proteome analysis. In this study, we carried out heating the sample prior to trypsin digestion using an instrument to improve the tryptic digestion process. The heat shock generated by the system efficiently denatured proteins in the sample and increased the reproducibility in quantitative proteomics based on peptide abundance measurements. To demonstrate the effectiveness of the protocol, three cell lines (A human lung cancer cell line (A549), a human embryonic kidney cell line (HEK293T), and a human colorectal cancer cell line (HCT-116)) were selected and the effect of heat shock was compared to that of normal tryptic digestion processes. The tryptic digests were desalted and analysed by LC-MS/MS, the results showed 57 and 36% increase in the number of identified unique peptides and proteins, respectively, than conventional digestion. Heat shock treated samples showed higher numbers of shorter peptides and peptides with low inter-sample variation among triplicate runs. Quantitative LC-MS/MS analysis of heat shock treated sample yielded peptides with smaller relative error percentage for the triplicate run when the peak areas were compared. Exposure of heat-shock to proteomic samples prior to proteolysis in conventional digestion process can increase the digestion efficiency of trypsin resulting in production of increased number of peptides eventually leading to higher proteome coverage.

• Herbal Formula Science
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• v.10 no.1
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• pp.157-167
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• 2002

This study was performed to investigate what effect the taste and quality of drugs would have on the cold and heat mechanisms of human body. We administered Hwangryeunhaedok-tang composed of bitter-tasted, cold-qualified drugs and Gungangbuza-tang composed of spice-tasted. hot-qualified drugs, respectively to the mice 1 hr before exposure to heat stress or cold stress. Plasma corticosterone level of mice was measured. The results were as follows: 1. The elevated corticosterone level in the mice exposed to heat stress was significantly decreased after administration of Gungangbuza-tang but there was no decrease after administration of Hwangryeunhaedok-tang. 2. The elevated corticosterone level in the mice exposed to cold stress was significantly decreased after administration of Hwangryeunhaedok-tang but there was mild decrease after administration of Gungangbuza-tang. 3. When the doses, 3g/kg and 1g/kg were administerd to mice exposed to heat stress. both dose showed significant decrease of corticosterone level and the dose. 3g/kg was more effective. However, in the mice exposed to cold stress, the dose, 3g/kg showed mild decrease and 1g/kg showed significant decrease. These data suggested that HW decreased the plasma corticosterone level in the mice exposed to cold stress and GB also decreased the plasma corticosterone level in the mice exposed to heat stress. In conclusion, our study revealed that the taste and quality of drugs controled the cold and heat mechanism of human body.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.263-269
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• 2018

Objective: Heat stress (HS) triggers oxidative stress and respiratory alkalosis in pigs. The objective of this experiment was to study whether a short-term supranutritional amount of dietary vitamin E (VE) can mitigate oxidative stress and respiratory alkalosis in heat-stressed pigs. Methods: A total of 24 pigs were given either a control diet (17 IU/kg VE) or a high VE (200 IU/kg VE; HiVE) diet for 14 d, then exposed to thermoneutral (TN; $20^{\circ}C$, 45% humidity) or HS ($35^{\circ}C$, 35% to 45% humidity, 8 h daily) conditions for 7 d. Respiration rate and rectal temperature were measured three times daily during the thermal exposure. Blood gas variables and oxidative stress markers were studied in blood samples collected on d 7. Results: Although HiVE diet did not affect the elevated rectal temperature or respiration rate observed during HS, it alleviated (all p<0.05 for diet${\times}$temperature) the loss of blood $CO_2$ partial pressure and bicarbonate, as well as the increase in blood pH in the heat-stressed pigs. The HS reduced (p = 0.003) plasma biological antioxidant potential (BAP) and tended to increase (p = 0.067) advanced oxidized protein products (AOPP) in the heat-stressed pigs, suggesting HS triggers oxidative stress. The HiVE diet did not affect plasma BAP or AOPP. Only under TN conditions the HiVE diet reduced the plasma reactive oxygen metabolites (p<0.05 for diet${\times}$temperature). Conclusion: A short-term supplementation with 200 IU/kg VE partially alleviated respiratory alkalosis but did not reduce oxidative stress in heat-stressed pigs.

• Safety and Health at Work
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• v.14 no.2
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• pp.215-221
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• 2023

Background: There is little information about the airborne hazardous agents released during the heat treatment when manufacturing a welding material. This study aimed to evaluate the airborne hazardous agents generated at welding material manufacturing sites through area sampling. Methods: concentration of airborne particles was measured using a scanning mobility particle sizer and optical particle sizer. Total suspended particles (TSP) and respirable dust samples were collected on polyvinyl chloride filters and weighed to measure the mass concentrations. Volatile organic compounds and heavy metals were analyzed using a gas chromatography mass spectrometer and inductively coupled plasma mass spectrometer, respectively. Results: The average mass concentration of TSP was 683.1±677.4 ㎍/m³, with respirable dust accounting for 38.6% of the TSP. The average concentration of the airborne particles less than 10 ㎛ in diameter was 11.2-22.8×10⁴ particles/cm³, and the average number of the particles with a diameter of 10-100 nm was approximately 78-86% of the total measured particles (<10 ㎛). In the case of volatile organic compounds, the heat treatment process concentration was significantly higher (p < 0.05) during combustion than during cooling. The airborne heavy metal concentrations differed depending on the materials used for heat treatment. The content of heavy metals in the airborne particles was approximately 32.6%. Conclusions: Nanoparticle exposure increased as the number of particles in the air around the heat treatment process increases, and the ratio of heavy metals in dust generated after the heat treatment process is high, which may adversely affect workers' health.

• Journal of Wellbeing Management and Applied Psychology
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• v.7 no.2
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• pp.49-56
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• 2024

Purpose: Construction sites are currently facing a socialization problem as the incidence of thermal disease-related disasters increases due to summer heat waves, exacerbated by factors like the concentration of middle-aged and older workers and global warming. The reason why construction sites are particularly vulnerable to heat waves is that there are many outdoor work, which is the peculiarity of the construction industry, and most of the construction workers are elderly. This study analyzes disaster statistics of workers at construction sites for five years to investigate the occurrence of thermal diseases and analyze factors through disaster cases to provide basic data for future disasters to be reduced. Research design, data, and methodology: According to the Construction Workers' Mutual Aid Association, as of June, more than 60% of the construction workers working in the field were in their 50s and 60s. More than 24% are in their 60s and older. Thermal diseases caused by heat waves occur when exposed to high heat or strong sunlight for a long time, accompanied by headaches and dizziness. The problem is that many elderly people have underlying diseases, so if they lose consciousness, they cannot easily recover and are likely to die. Results: According to industrial accident statistics, 182 people were injured by heat-related diseases in the summer from 2016 to 2021, of which 29 died. In particular, in the construction industry, which has a lot of outdoor work, 87 people were injured and 20 people died. Conclusions: In order to prevent heat diseases caused by outdoor work, it is emphasized that exposure time is controlled, and sufficient rest and hydration are essential. Rest, water, and shade are in line with the three principles.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.527-536
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• 2019

This study examines the degradation of PTT BCF and fading behavior of disperse dye by heat treatment and UV irradiation. The behavior in strength degradation of PTT BCF after treat treatment was examined by measuring the tensile strength of samples. The strength retention of PTT BCF rapidly decreased with increasing exposure time at 150℃. The K/S value decreased with increasing temperature and its trend accelerated with increasing exposure time on heat. The behavior on strength degradation of PTT BCF and the fading of disperse dye on it were studied under UV irradiation at various temperatures. The tensile strength of PTT BCF and the K/S value of the sample dyed with disperse dye after UV irradiation decreased with increasing temperature and exposure time. PTT BCF exposed under UV irradiation exhibited lower strength and K/S value compared with the sample after heat treatment. Additional study on the effects of additives used to improve the resistance to fading of disperse dye and degradation of PTT BCF revealed that antioxidant and UV absorbent in PTT BCF showed a small improvement in the strength degradation of PTT BCF and the fading of dye.

• Korean Journal of Ecology and Environment
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• v.49 no.1
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• pp.22-30
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• 2016

Environmental changes exert harmful effects on organisms inhabiting coastal regions. These changes are also associated with reduced production in aquaculture farms. In this study, we investigated internal and external responses of two Bivalvia species (Crassostrea gigas and Mytilus galloprovincialis) in Gamak Bay under stressful environmental conditions in aquaculture farms. We investigated external responses such as weight, size, and environment exposure time, and analyzed the expression of the HSP70 gene. C. gigas HSP70 gene expression level was significantly high in the C3 aquaculture farm site, but the weight and size of C. gigas were high in the C2 aquaculture farm site. The response of C. gigas HSP70 mRNA was associated with the environmental exposure time in each aquaculture farm. Expression of M. galloprovincialis HSP70 gene was found to be significantly higher in the M2 aquaculture farm site than in the M1 site, whereas the weight of M. galloprovincialis was observed to be higher in the M1 site. The size and environmental exposure time of M. galloprovincialis were similar between M1 and M2 sites. In addition, HSP70 sequences of C. gigas and M. galloprovincialis showed high similarity with that of another marine species. According to our results, there were differences in internal responses following environmental stress in aquaculture farms, with respect to HSP70 gene expression. The results suggest that the HSP70 gene is a useful molecular indicator for monitoring stress responses in Bivalvia species in the field.