• Title/Summary/Keyword: exposure control factors

Search Result 276, Processing Time 0.027 seconds

Statistical Modeling of the Pretilt Angle Control in Nematic Liquid Crystal using In-situ Photoalignment Method on Plastic Substrate

  • Kang, Hee-Jin;Lee, Jung-Hwan;Yun, Il-Gu;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
    • /
    • v.7 no.3
    • /
    • pp.145-148
    • /
    • 2006
  • In this study, the response surface modeling of the pretilt angle control using in-situ photoalignment method with oblique UV exposure .on plastic substrate is investigated. The pretilt angle is the main factor to determine the alignment of the liquid crystal display. The response surface model is used to analyze the variation of the pretilt angle on the various process conditions. Heating temperature and UV exposure time are considered as input factors. The liquid crystal (LC) pretilt angle increased with increasing heating temperature and UV exposure time. The analysis of variance is used to analyze the statistical significance and the effect plots are also investigated to examine the relationship between the process parameters and the response.

Exposure to Tobacco Advertising and Promotion among School Children Aged 13-15 in Vietnam - an Overview from GYTS 2014

  • Tran, Khanh Long;Phung, Xuan Son;Kim, Bao Giang;Phan, Thi Hai;Doan, Thi Thu Huyen;Luong, Ngoc Khue;Pham, Thi Quynh Nga;Nguyen, Tuan Lam;Hoang, Van Minh;Le, Thi Thanh Huong
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.sup1
    • /
    • pp.49-53
    • /
    • 2016
  • Evidence shows that tobacco advertising and promotion activities may increase tobacco consumption and usage, especially in youth. Despite the regulation on prohibiting advertisement of any tobacco product, tobacco advertisement and promotion activities are still common in Vietnam. This article presents current exposure to tobacco advertising and promotion (TAP) among school children aged 13 to 15 years in Vietnam in 2014 and potential influencing factors. Data from the Global Youth Tobacco Survey 2014 in Vietnam covering 3,430 school aged children were used. Both descriptive and analytical statistics were carried out with Stata 13 statistical software. Binary logistic regression was applied to explain the exposure to TAP among youth and examine relationships with individual factors. A significance level of p<0.05 and sampling weights were used in all of the computations. In the past 30 days, 48.6% of the students experienced exposure to at least 1 type of tobacco advertising or promotion. Wearing or otherwise using products related to tobacco was the most exposure TAP type reported by students (22.3%). The internet (22.1), points of sales (19.2) and social events (11.5) were three places that students aged 13-15 frequently were exposed to TAP. Binary logistic results showed that gender (female vs male) (OR = 0.61, 95%CI: 0.52 - 0.71), susceptibility to smoking (OR = 2.12, 95%CI: 1.53 - 2.92), closest friends' smoked (OR = 1.43, 95%CI: 1.2 - 1.7) and parents smoking status (OR = 2.83, 95%CI: 1.6 - 5.01) were significantly associated with TAP exposure among school-aged children. The research findings should contribute to effective implementation of measures for preventing and controlling tobacco use among students aged 13-15 in Viet Nam.

Automatic Exposure Control Performance Evaluation of Digital Radiographic Imaging System by Manufacturer Using Coins (동전을 이용한 제조사 별 디지털 방사선 영상 시스템의 자동노출제어 성능 평가)

  • Lim, Se-Hun;Seoung, Youl-Hun
    • Journal of radiological science and technology
    • /
    • v.45 no.1
    • /
    • pp.1-9
    • /
    • 2022
  • In this study, we proposed an image quality control for an automatic exposure control (AEC) of digital radiographic imaging system and tried to analyze the performance of the AEC by various manufacturer. The subjects of the experiment were analyzed for the AEC image quality evaluation using digital radiation generators from four manufacturer such as PHILIPS, GE Healthcare, SAMSUNG Healthcare, DK Medical Solution. We used as materials for the implementation of the image quality evaluation by coins (500 won, KOMSCO, Korea). This study evaluated the performance evaluation of the AEC as image quality and exposure dose (Milliampere-seconds; mAs). The image quality evaluation was tried visual assessment by two radiologic technologists and contrast to noise (CNR) by ImageJ. The exposure dose investigated mAs on digital radiation generators. The radiographic coin images acquired 360 images based on change in the control factors of the AEC, which were kVp, the consistency of field configuration and dominant zone, sensitivity and density. As a result, there was a significant difference in the AEC performance between manufacturer. The CNR by the AEC for each manufacturer showed a difference of up to about 1.9 times. The exposed tube current by the AEC for each manufacturer showed a difference of up to about 5.8 times. It is expected that our proposed evaluation method using coins could be applied as the AEC performance evaluation method in the future.

Observation of Back Scattering and Exposure-Factors (후방산란(後方散亂)과 노출배수(露出倍數)에 관(關)한 검토(檢討))

  • Huh, Joon;Kim, Chang-Kyun;Kang, Hong-Seok;Lee, Sun-Sook;Lee, Jwa-Ryong;Youn, Chul-Ho
    • Journal of radiological science and technology
    • /
    • v.5 no.1
    • /
    • pp.15-19
    • /
    • 1982
  • Authors made an experiment to know the relation of surface doses and multiple factors of exposure by using grids, fields, tube voltages objects and distances and obtained the results as follows: 1. Surface doses were increased in proportion to the thickness of objects. 2. Surface doses were more influenced when irradiated fields were small and tube voltages were low. 3. Surface doses were a logarthmic proportion to the focus-object distance. 4. Multiple factors of exposure by using grid were under the control of the thickness of objects, irradiated fields and tube voltages but the relation of them were not fixed.

  • PDF

Sun Exposure and the Risk of Prostate Cancer in the Singapore Prostate Cancer Study: a Case-control Study

  • Chia, Sin-Eng;Wong, Kin-Yoke;Cheng, Christopher;Lau, Weber;Tan, Puay-Hoon
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.7
    • /
    • pp.3179-3185
    • /
    • 2012
  • Background: Most of the epidemiology studies on the effects of sun exposure and prostate cancer were conducted among the temperate countries of North America and Europe. Little is known about the influence on Asian populations. The purpose of current study was to evaluate any association of sun exposure with risk of prostate cancer in Chinese, Malays and Indians who reside in the tropics. Methods: The Singapore Prostate Cancer Study is a hospital-based case-control study of 240 prostate cancer incident cases and 268 controls conducted in Singapore between April 2007 and May 2009. Detailed information on outdoor activities in the sun, skin colour, sun sensitivity and other possible risk factors were collected in personal interviews. Cases were further classified by Gleason scores and TNM staging. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis, adjusted for age, ethnicity, education, family history of any cancers, BMI and skin colour. Results: We found that prostate cancer risk was increased in subjects with black/dark-brown eyes (OR 5.88, 95%CI 3.17-10.9), darker skin colour e.g. tan/dark brown/black (OR 7.62, 95%CI 3.41-17.0), frequent sunburn in lifetime (OR 4.30, 95%CI 1.7-11.2) and increased general sun exposure in adulthood per week (OR 2.03, 95%CI 1.09-3.81). The increased risk was consistent for high grade tumours and advanced stage prostate cancers. Conclusion: The findings from this study suggest that excessive sun exposure is a risk factor for prostate cancer in Asians.

Health Risk Assessment for Workers Exposed to Diazinon Insecticide (디아지논 취급 근로자의 건강 위험성 평가)

  • Jung, Woo Jin;Kim, Chi Nyon;Won, Jong Uk;Kim, Ki Youn;Roh, Jaehoon
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.22 no.2
    • /
    • pp.100-106
    • /
    • 2012
  • Objectives: Diazinon is an insecticide which acts as a contact stomach and respiratory poison, and used throughout the world to control a wide range of sucking and chewing insects and mites on a range of crops. In this study, the airborne diazinon levels were measured for farmers, pest control operaters, landscapers, and agricultural chemicals sellers, and an assessment of the health risk to the workers was presented. The exposure scenario was based on the route of inhalation and skin absorption. The "OSHA Method No. 62" was used to sample and measure the airborne diazinon levels. The skin wipe method was applied to measure the level of the diazinone exposure through the skin. For the determination of exposure scenario, the exposure factors were surveyed for the daily average inhalation rate and the exposure period and frequency and time of diazinone as well as the body weight and lifetime of the workers. The median values of exposure frequency and exposure time were selected after evaluating the validity of those. Methods: The highest level of the diazinon exposure in the air was $107.21ug/m^3$ in farmers, followed by $93.53ug/m^3$ in landscapers, at $31.40ug/m^3$ in pest control operators, and $1.04ug/m^3$ in agricultural chemical seller. The amount of skin absorption was the highest in farmers at 63.39 ug/day, followed by landscapers at 10.47 ng/day, pest control operaters at 4.26 ng/day, and agricultural chemicals sellers at 0.34 ng/day. The hazardous indices calculated using toxicological reference value were 2.79 for pest control operaters, 0.41 for landscapers, 0.07 for agricultural chemicals sellers, and 0.06 for farmers. Conclusions: While the farmers were exposed to the high levels of diazinon through the air and skin, the pest control operaters, landscapers and agricultural chemicals sellers have more the diazinon hazards than the farmer based on the risk assessment in this study.

A Control Room Dose Assessment for a 1300 MWe PWR Following a Loss of Coolant Accident (냉각재(冷却材) 상실사고시(喪失事故時) 1300 MWe 급(級) PWR원전(原電) 주제어실(主制御室)의 선량평가(線量評價))

  • Chang, Si-Young;Ha, Chung-Woo
    • Journal of Radiation Protection and Research
    • /
    • v.14 no.1
    • /
    • pp.34-45
    • /
    • 1989
  • The habitability of a reactor control room in a French 1300 MWe P'4 type PWR has been evaluated through the exposure dose assessment for the reactor operator following a Loss of Coolant Accident. The main hypotheses adopted in this evaluation are based on the French Standard Safety Analysis Report. A simple computer program, named COREX(Control Room EXposure), was developed to calculate : the time-integrated radioactivities released from the reactor building, the volume factors for radionuclides concerned and the resulting time-integrated external whole body and internal thyroid doses to the reactor operators staying in the control room up to 30 days following the LOCA. The results obtained in this study, on the whole, well agreed with those proposed by the EDF(Electricite de France) except for the case of the whole body exposure, which was attributed to the differences in the volume factors for the radionuclides concerned.

  • PDF

Prevention of Invasive Candida Infections in the Neonatal Intensive Care Unit (신생아 집중치료실에서 침습 칸디다 감염의 예방)

  • Kim, Chun Soo
    • Pediatric Infection and Vaccine
    • /
    • v.18 no.1
    • /
    • pp.15-22
    • /
    • 2011
  • Invasive Candida infections (ICI) have become the third most common cause of late-onset infection among premature infants in the neonatal intensive care unit (NICU). Risk factors include birth weight less than 1,000 g, exposure to more than two antimicrobials, third generation cephalosporin exposure, parenteral nutrition including lipid emulsion, central venous catheter, and abdominal surgery. Candida colonization of the skin and gastrointestinal tract is an important first step in the pathogenesis of invasive disease. Strict infection control measures against the infection should be done in the NICU. The following practices are likely to contribute to reducing the rate of ICI: (1) restriction of broad-spectrum antibiotics, antacids and steroid; (2) introduction of early feeding and promoting breast milk. Fluconazole prophylaxis may be an effective control measure to prevent Candida colonization and infections in individual units with high incidence of fungal infection. In addition, there is a need of further data including the development of resistant strains and the effect on long-term neurodevelopmental outcomes of infants exposed to drugs before the initiation of routine application of antifungal prophylaxis in the NICU.

Effects of Waterborne Iron on Serum Iron Concentration and Iron Binding Capacity of Olive Flounder (Paralichthys olivaceus)

  • Jee Jung-Hoon;Kim Seong-Gil;Kang Ju-Chan
    • Fisheries and Aquatic Sciences
    • /
    • v.7 no.1
    • /
    • pp.23-28
    • /
    • 2004
  • Olive flounder (Paralichthys olivaceus) was exposed to waterborne iron (0.1, 0.5, 1, 5 and 10 mg/L) for 50 days. The effects of iron on blood iron status and iron binding capacity were studied. The serum iron concentration was significantly higher than in the group exposed to iron (1, 5 and 10 mg/L) in comparison to the control after 30 days of exposure to iron. A significant decrease in unsaturated iron binding capacity was found between the control and the group exposed to iron (5 and 10 mg/L, respectively) at 40 and 50 days, respectively. The total iron binding capacity of serum in the fish exposed to iron concentrations (5 and 10 mg/L) showed a significant decrease compared to that of the control at 40 days after iron exposure. Serum iron saturation values increased in the flounder exposed to iron concentration (5 and 10 mg/L) at 50 days. Our data suggest that sub-lethal exposure of waterborne iron alters the blood iron concentration and iron binding capacity, and these parameters seems to be valuable factors for screening and diagnosis of iron overload syndromes in fish.

Correlation among PM10, PM2.5, Cd, and Pb Concentrations in Ambient Air and Asian Dust Storm Event (황사 발생과 대기 중 PM10, PM2.5, Cd, Pb 농도의 상관성)

  • Moon, Chan-Seok
    • Journal of Environmental Health Sciences
    • /
    • v.46 no.5
    • /
    • pp.532-538
    • /
    • 2020
  • Objectives: The study evaluated correlations among monthly PM2.5, PM10, Cd, Pb concentrations and the number of Asian dust days. Methods: Based on data from 'The annual report on air quality in Korea from 1999 to 2017', concentrations of PM10, PM2.5, Cd, Pb, and the number of Asian dust days were recalculated to mean, standard deviation, minimum, and maximum. Correlation coefficients were calculated among PM2.5, PM10, Cd, Pb, and Asian dust days. Results: Asian dust days were correlated only with PM10 among the four factors of PM10, PM2.5, Cd, and Pb. The four factors of PM10, PM2.5, Cd, and Pb were very significantly correlated with each other (p<0.01). Their correlation coefficients for PM10 were 0.800 for PM2.5, 0.823 for Cd, and 0.892 for Pb. PM2.5 was also correlated strongly with Cd (0.845) and Pb (0.830). Cd had a correlation with Pb of 0.971. The maximums of PM2.5, PM10, and Pb were shown to exceed the atmospheric environmental standard of Korea, which necessitates national continuous exposure control. Based on exposure data, Asian dust days were thought to be an exposure factor for Cd and Pb. Conclusion: Asian dust might be a factor in Cd and Pb exposure. National exposure controls are required for exposure to PM2.5, PM10, Cd, and Pb.