• 제목/요약/키워드: Key Exposure

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Building Green Entrepreneurship: A Journey of Environmental Awareness to Green Entrepreneurs in Thailand

  • Tesprasit, Kornthong;Aksharanandana, Pakatip;Kanchanavibhu, Athikom
    • Journal of Information Technology Applications and Management
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    • v.27 no.5
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    • pp.35-47
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    • 2020
  • Global waste has become a global issue and we can see the new trend of discovery businesses established to focus on solving the waste problem using new renewable energy technology and the circular economy business model. This paper aims to study factors that impact green entrepreneurship in Thailand, such as environmental concern, organizational environment, founder demographics, education background, entrepreneurship awareness, as well as external factors of a business. The study analyzes the data from three qualitative in-depth interviews with green entrepreneur founders who started the businesses in polymer up-cycling, waste management, and renewable energy. The study finds overseas educational background to be one of the key main drivers for the entrepreneurial courage to decide to pursue a new business venture. By having the exposure toward the different culture, three entrepreneurs hands-on experiential learning through three key drivers who are composed of the can-do attitude, the willingness to be self-employed, and the way of seeking for the freedom to express their passions.

The physicochemical Characterization of ETS (Environmental Tobacco Smoke) (Environmental Tobacco Smoke의 이화학적 특성)

  • 이문수
    • Journal of the Korean Society of Tobacco Science
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    • v.17 no.1
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    • pp.79-97
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    • 1995
  • On the basis of the literature, which is at present still scientific information improvable, the results of research done so far into the occurrence and analytical methodology of major markers of environmental tobacco smoke(ETS) have been summarized. Key areas addressed are: differences in physicochemical composition between mainstream smoke, sidestream smoke and ETS: techniques for field measurement of ETS: relationship between indoor air quality with ETS and its distribution view of US EPA and its problems: biological effects and concerning estimation of ETS exposure.

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The Effect of Equilibration Temperature and Exposure Time on the Ultrarapid Freezing of 1-cell Mouse Zygote (생쥐 1-세포기배의 초급속 동결에 있어서 평형 온도와 노출시간의 영향)

  • Chung, Duk-Soo;Kim, Hyung-Kuk;Park, In-Kook
    • Clinical and Experimental Reproductive Medicine
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    • v.25 no.3
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    • pp.261-268
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    • 1998
  • The present study was to assess the effect of ultrarapid freezing on the development of 1-cell mouse zygote using cryoprotectants, DMSO (dimethyl sulfoxide) or PROH (1,2-propanediol). We investigated the effect of the type and concentration of cryoprotectant, and of the temperature and time of prefreezing equilibration on their capacity to develop to the blastocyst stage in vitro. The concenration, the equilibration temperature, and the exposure time seemed to serve as an important factor in ultrarapid freezing of 1-cell mouse zygotes. In addition to the exposure time and the concentration of cryoprotectant appeared to playa key role in the development of the embryo. In general, the development of the embryo was more effective at $3^{\circ}C$ than $23^{\circ}C$ and 4.5 M than 3 M for 3 to 5 minutes. At $23^{\circ}C$ the development of the embryo was stimulated by DMSO while at $3^{\circ}C$ it was stimulated by PROH. Thus it has been suggested that there exists a correlation between the concentration of cryoprotectants and exposure time in the development of the embryo. In conclusion, we found that for ultrarapid freezing of mouse 1-cell embryos in DMSO, or PROH-based solution, viability shown optimum depending on the cryoprotectant, the concentration of the cryoprotectant and on the temperature and the duration of equilibration.

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$PM_{10}$ Exposure and Non-accidental Mortality in Asian Populations: A Meta-analysis of Time-series and Case-crossover Studies

  • Park, Hye Yin;Bae, Sanghyuk;Hong, Yun-Chul
    • Journal of Preventive Medicine and Public Health
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    • v.46 no.1
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    • pp.10-18
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    • 2013
  • Objectives: We investigated the association between particulate matter less than $10{\mu}m$ in aerodynamic diameter ($PM_{10}$) exposure and non-accidental mortality in Asian populations by meta-analysis, using both time-series and case-crossover analysis. Methods: Among the 819 published studies searched from PubMed and EMBASE using key words related to $PM_{10}$ exposure and non-accidental mortality in Asian countries, 8 time-series and 4 case-crossover studies were selected for meta-analysis after exclusion by selection criteria. We obtained the relative risk (RR) and 95% confidence intervals (CI) of non-accidental mortality per $10{\mu}g/m^3$ increase of daily $PM_{10}$ from each study. We used Q statistics to test the heterogeneity of the results among the different studies and evaluated for publication bias using Begg funnel plot and Egger test. Results: Testing for heterogeneity showed significance (p<0.001); thus, we applied a random-effects model. RR (95% CI) per $10{\mu}g/m^3$ increase of daily $PM_{10}$ for both the time-series and case-crossover studies combined, time-series studies relative risk only, and case-crossover studies only, were 1.0047 (1.0033 to 1.0062), 1.0057 (1.0029 to 1.0086), and 1.0027 (1.0010 to 1.0043), respectively. The non-significant Egger test suggested that this analysis was not likely to have a publication bias. Conclusions: We found a significant positive association between $PM_{10}$ exposure and non-accidental mortality among Asian populations. Continued investigations are encouraged to contribute to the health impact assessment and public health management of air pollution in Asian countries.

The Effects of Long-Term, Low-Level Exposure to Monocyclic Aromatic Hydrocarbons on Worker's Insulin Resistance

  • Won, Yong-Lim;Ko, Yong;Heo, Kyung-Hwa;Ko, Kyung-Sun;Lee, Mi-Young;Kim, Ki-Woong
    • Safety and Health at Work
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    • v.2 no.4
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    • pp.365-374
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    • 2011
  • Objectives: This study was designed to investigate whether long-term, low-level exposure to monocyclic aromatic hydrocarbons (MAHs) induced insulin resistance. Methods: The subjects were 110 male workers who were occupationally exposed to styrene, toluene, and xylene. One hundred and ten age-matched male workers who had never been occupationally exposed to organic solvents were selected as a control group. Cytokines, which have played a key role in the pathogenesis of insulin resistance, and oxidative stress indices were measured. Assessment of exposure to MAHs was performed by measuring their ambient levels and their urinary metabolites in exposed workers, and the resulting parameters between the exposed group and non-exposed control groups were compared. Results: There was no significant difference in general characteristics and anthropometric parameters between the two groups; however, total cholesterol, fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance levels were significantly higher in the exposed group. Phenylglyoxylic acid levels showed significant association with tumor necrosis factor-${\alpha}$, total oxidative status, and oxidative stress index via multiple linear regression analysis. Further, there was a negative correlation between methylhippuric acid levels and total anti-oxidative capacity, and there was a significant relationship between MAHs exposure and fasting glucose levels, as found by multiple logistic regression analysis (odds ratio = 3.95, 95% confidence interval = 1.074-14.530). Conclusion: This study indicated that MAHs increase fasting glucose level and insulin resistance. Furthermore, these results suggested that absorbing the organic solvent itself and active metabolic intermediates can increase oxidative stress and cytokine levels, resulting in the changes in glucose metabolism and the induction of insulin resistance.

Numerical and experimental analysis on the axial compression performance of T-shaped concrete-filled thin-walled steel

  • Xuetao Lyu;Weiwei Wang;Huan Li;Jiehong Li;Yang Yu
    • Steel and Composite Structures
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    • v.50 no.4
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    • pp.383-401
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    • 2024
  • The research comprehensively studies the axial compression performance of T-shaped concrete-filled thin-walled steel tubular (CTST) long columns after fire exposure. Initially, a series of tests investigate the effects of heating time, load eccentricity, and stiffeners on the column's performance. Furthermore, Finite Element (FE) analysis is employed to establish temperature and mechanical field models for the T-shaped CTST long column with stiffeners after fire exposure, using carefully determined key parameters such as thermal parameters, constitutive relations, and contact models. In addition, a parametric analysis based on the numerical models is conducted to explore the effects of heating time, section diameter, material strength, and steel ratio on the axial compressive bearing capacity, bending bearing capacity under normal temperature, as well as residual bearing capacity after fire exposure. The results reveal that the maximum lateral deformation occurs near the middle of the span, with bending increasing as heating time and eccentricity rise. Despite a decrease in axial compressive load and bending capacity after fire exposure, the columns still exhibit desirable bearing capacity and deformability. Moreover, the obtained FE results align closely with experimental findings, validating the reliability of the developed numerical models. Additionally, this study proposes a simplified design method to calculate these mechanical property parameters, satisfying the ISO-834 standard. The relative errors between the proposed simplified formulas and FE models remain within 10%, indicating their capability to provide a theoretical reference for practical engineering applications.

Assessment of Occupational Health Risks for Maintenance Work in Fabrication Facilities: Brief Review and Recommendations

  • Dong-Uk Park;Kyung Ehi Zoh;Eun Kyo Jeong;Dong-Hee Koh;Kyong-Hui Lee;Naroo Lee;Kwonchul Ha
    • Safety and Health at Work
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    • v.15 no.1
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    • pp.87-95
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    • 2024
  • Background: This study focuses on assessing occupational risk for the health hazards encountered during maintenance works (MW) in semiconductor fabrication (FAB) facilities. Objectives: The objectives of this study include: 1) identifying the primary health hazards during MW in semiconductor FAB facilities; 2) reviewing the methods used in evaluating the likelihood and severity of health hazards through occupational health risk assessment (OHRA); and 3) suggesting variables for the categorization of likelihood of exposures to health hazards and the severity of health effects associated with MW in FAB facilities. Methods: A literature review was undertaken on OHRA methodology and health hazards resulting from MW in FAB facilities. Based on this review, approaches for categorizing the exposure to health hazards and the severity of health effects related to MW were recommended. Results: Maintenance workers in FAB facilities face exposure to hazards such as debris, machinery entanglement, and airborne particles laden with various chemical components. The level of engineering and administrative control measures is suggested to assess the likelihood of simultaneous chemical and dust exposure. Qualitative key factors for mixed exposure estimation during MW include the presence of safe operational protocols, the use of air-jet machines, the presence and effectiveness of local exhaust ventilation system, chamber post-purge and cooling, and proper respirator use. Using the risk (R) and hazard (H) codes of the Globally Harmonized System alongside carcinogenic, mutagenic, or reprotoxic classifications aid in categorizing health effect severity for OHRA. Conclusion: Further research is needed to apply our proposed variables in OHRA for MW in FAB facilities and subsequently validate the findings.

Effects of Lead and Particulate Montmorillonite on Growth Performance, Hormone and Organ Weight in Pigs

  • Yu, DongYou;Xu, Z.R.;Yang, X.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.12
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    • pp.1775-1779
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    • 2005
  • Seventy-two crossbred gilts of approximately 33 kg initial weight were used in this study. The gilts were randomly assigned into three groups. The three dietary treatments were basal diet only (control group), basal diet+10 mg/kg lead, and basal diet+10 mg/kg lead+0.5% particulate montmorillonite (PM). The results showed that the addition of lead to the diet decreased significantly the body weight and feed efficiency, but PM could restore body weight and feed efficiency of gilts compared to the Pb exposure group. There were no significant differences in weights of ovaries and uteri with addition of either lead or PM to the diet. Supplementing the lead in the diet of gilts also significantly increased the concentration of lead in blood, decreased circulating lutenizing hormone (LH) and estradiol (E$_2$) levels in serum, the addition of PM to the diet effectively adsorbed and lowered lead concentration in the blood. These data suggested that lead disrupts the signals between the hypothalamus and pituitary gland in gilts, and possibly suppressed the secretion of relative growth hormone and sex hormone. On the other hand, PM may ameliorate Pb toxicity in pigs.

Smartphone-based OTP Door Lock System (스마트폰 기반의 OTP 도어락 시스템)

  • Kim, Jin-Bae;Oh, Chang-Seok;Jeong, Si-Yeong;Jeong, Sang-Heon;Kim, Tae Yong;Jang, Won-Tae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.560-563
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    • 2015
  • Door lock system is used for the conventional method by using a key or a card, a pad Replication, loss, and the risk of damage, and has a problem that exposure to others. In this paper, Bluetooth communication and OTP built into smartphones in order to complement the existing door lock system problems OTP(One-Time-Password), Hide-Key utilizing the authentication method and the Arduino smartphone-based design of wireless OTP door lock system by enabling users it allows for more convenient and safe life free from the risk of theft and robbery.

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