• Title/Summary/Keyword: inter-laboratory test

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Vibration Control of Working Booms on Articulated Bridge Inspection Robots (교량검사 굴절로봇 작업붐의 진동제어)

  • Hwang, In-Ho;Lee, Hu-Seok;Lee, Jong-Seh
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.5
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    • pp.421-427
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    • 2008
  • A robot crane truck is developed by the Bridge Inspection Robot Development Interface(BRIDI) for an automated and/or teleoperated bridge inspection. This crane truck looks similar to the conventional bucket crane, but is much smaller in size and light-weight. At the end of the telescoping boom which is 12m long, a robot platform is mounted which allows the operator to scan the bridge structure under the deck trough the camera. Boom vibration induced by wind and deck movement can cause serious problems in this scanning system. This paper presents a control system to mitigate such vibration of the robot boom. In the proposed control system, an actuator is installed at the end of the working boom. This control system is studied using a mathematical model analysis with LQ control algorithm and a scaled model test in the laboratory. The study indicates that the proposed system is efficient for the vibration control of the robot booms, thereby demonstrating its immediate applicability in the field.

"Beach Lifeguards' Sun Exposure and Sun Protection in Spain"

  • de Troya Martin, Magdalena;Sanchez, Nuria Blazquez;Garcia Harana, Cristina;Leiva, Ma Carmen Alarcon;Arjona, Jose Aguilera;Ruiz, Francisco Rivas;de Galvez Aranda, Ma Victoria
    • Safety and Health at Work
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    • v.12 no.2
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    • pp.244-248
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    • 2021
  • Background: Sunburn is the main avoidable cause of skin cancer. Beach lifeguards spend many hours exposed to the effects of solar radiation during their work day, precisely at times of the year when levels of solar irradiation are highest. The aim of this study is to quantify the risk to beach lifeguards of sun exposure. Methods: A descriptive cross-sectional study was carried out in the Western Costa del Sol, southern Spain, during the summer of 2018. The research subjects were recruited during a skin cancer prevention course for beach lifeguards. All participants were invited to complete a questionnaire on their habits, attitudes, and knowledge related to sun exposure. In addition, ten were specially monitored using personal dosimeters for three consecutive days, and the results were recorded in a photoprotection diary. A descriptive analysis (mean and standard deviation for the quantitative variables) was performed, and inter-group differences were evaluated using the Mann-Whitney U test. Results: Two hundred fifteen lifeguards completed the questionnaire, and 109 met the criteria for inclusion in this analysis. The mean age was 23.8 years (SD: 5.1), 78.0% were male, 71.5% were phototype III or IV (Fitzpatrick's phototype), and 77.1% had experienced at least one painful sunburn during the previous summer. The mean daily personal ultraviolet exposure per day, the minimal erythema dose, and the standard erythema dose, in J/m2, were 634.7 [standard deviation (SD): 356.2], 2.5 (SD: 1.4) and 6.35 (SD: 3.6), respectively. Conclusion: Beach lifeguards receive very high doses of solar radiation during the work day and experience correspondingly high rates of sunburn. Intervention strategies to modify their sun exposure behavior and working environment are necessary to reduce the risk of skin cancer for these workers and to promote early diagnosis of the disease.

A Correlation Study between the Environmental, Personal Exposures and Biomarkers for Volatile Organic Compounds (대기 중 휘발성유기오염물질의 환경, 개인 및 인체 노출의 상관성 연구)

  • Jo, Seong-Joon;Shin, Dong-Chun;Chung, Yong;Breysse, Patrick N.
    • Environmental Analysis Health and Toxicology
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    • v.17 no.3
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    • pp.197-205
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    • 2002
  • Volatile organic compounds (VOCs) are an important public health problem throughout the world. Many important questions remain to be addressed in assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in the analytical determination of VOCs. Personal exposure measurements are needed to evaluate the relationship between microenvironmental concentrations and actual exposures. It is also important to investigate exposure frequency, duration, and intensity, as well as personal exposure characteristics. In addition to air monitoring, biological monitoring may contribute significantly to risk assessment by allowing estimation of absorbed doses, rather than just the external exposure concentrations, which are evaluated by environmental and personal monitoring. This study was conducted to establish the analytic procedure of VOCs in air, blood, urine and exhaled breath and to evaluate the relationships among these environmental media. The subjects of this study were selected because they are occupationally exposed to high levels of VOCs. Environmental, personal, blood, urine and exhalation samples were collected. Purge & trap, thermal desorber, gas chromatography and mass selective detector were used to analyze the collected samples. Analytical procedures were validated with the“break through test”, 'quot;recovery test for storage and transportation”,“method detection limit test”and“inter-laboratory QA/QC study”. Assessment of halogenated compounds indicted that they were significantly correlated to each other (p value < 0.01). In a similar manner, aromatic compounds were also correlated, except in urine sample. Linear regression was used to evaluate the relationships between personal exposures and environmental concentrations. These relationships for aromatic and halogenated are as follows: Halogen $s_{personal}$ = 3.875+0.068Halogen $s_{environmet}$, ($R^2$= .930) Aromatic $s_{personal}$ = 34217.757-31.266Aromatic $s_{environmet}$, ($R^2$= .821) Multiple regression was used to evaluate the relationship between exposures and various exposure deter-minants including, gender, duration of employment, and smoking history. The results of the regression model-ins for halogens in blood and aromatics in urine are as follows: Halogen $s_{blood}$ = 8.181+0.246Halogen $s_{personal}$+3.975Gender ($R^2$= .925), Aromatic $s_{urine}$ = 249.565+0.135Aromatic $s_{personal}$ -5.651 D.S ($R^2$ = .735), In conclusion, we have established analytic procedures for VOC measurement in biological and environmental samples and have presented data demonstrating relationships between VOCs levels in biological media and environmental samples. Abbreviation GC/MS, Gas Chromatography/Mass Spectrometer; VOCs, Volatile Organic Compounds; OVM, Organic Vapor Monitor; TO, Toxic Organicsapor Monitor; TO, Toxic Organics.

Impact of postoperative dietary types on nutrition and treatment prognosis in hospitalized patients undergoing oral and maxillofacial surgery: a comparative study

  • Sung Bin Youn;Se-Hui Ahn;Dong-Ho Cho;Hoon Myoung
    • Korean Journal of Community Nutrition
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    • v.29 no.2
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    • pp.129-143
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    • 2024
  • Objectives: The objective of this study is to compare a nutritionally balanced soft blend diet (SBD) with a soft fluid diet (SFD) on the health of inpatients who have undergone oral and maxillofacial (OMF) surgery, ultimately aiming to enhance care outcomes, improve health-related quality of life (QOL), and increase satisfaction with the hospital. Methods: Thirty-two patients were randomized into two groups: sixteen received SFD and sixteen received SBD. Anthropometric, laboratory evaluations were conducted upon admission and discharge. Patients filled out questionnaires on demographics, diet satisfaction, food intake amount, and health-related QOL on the day of discharge, assessed using the EuroQoL 5 Dimensions 3 Level and EuroQoL Visual Analogue Scale (EQ-VAS) instruments. Data were analyzed with descriptive statistics, χ2 tests for group differences, and paired nonparametric t-tests for within-group comparisons. The Mann-Whitney U test evaluated inter-group differences in preoperative weight and body mass index (BMI), postoperative changes, meal satisfaction, intake, health-related QOL, and self-assessed health status. P-values were set at a significance level of 0.05. Results: The SBD group had higher dietary intake (63.2% vs. 51.0%) and greater diet satisfaction (80.6 vs. 48.1, P < 0.0001) compared to SFD group. Health-related QOL, measured by EQ-VAS, was better in SBD group (70.3 vs. 58.8, P < 0.05). Postoperative weight and BMI decreased in SFD group but increased in SBD group (P < 0.01). Changes in laboratory results showed more stability in the SBD group. No postoperative infections were reported in SBD group, whereas SFD group had a 31.25% complication rate. Conclusions: While SFD is often recommended after OMF surgery to protect oral wound healing process, our study reveals that SBD not only enhances physical and psychological outcomes but also, somewhat unexpectedly, supports wound healing and reduces complications. Essentially, SBD promotes physical recovery and enhances health-related QOL than SFD by supporting both somatic and mental healing aspects.

The Validation of a Commercial Testosterone RIA Test Kits (Testosterone RIA 검사 kit 별 유효성 비교평가)

  • Ryu, Hwa-jin;Shin, Seon-yeong;Cho, Seong-uk
    • The Korean Journal of Nuclear Medicine Technology
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    • v.26 no.1
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    • pp.38-41
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    • 2022
  • Purpose Testosterone is a steroid hormone synthesized by the Leydig cells of the testes in men, and by the adrenal cortex and ovaries in women. Testosterone production is regulated by luteinzing hormone secreted by the anterior pituitary gland. In this experiment, the effectiveness of testosterone radioimmunoassay (RIA) kits produced by three companies was evaluated and compared in case the production of testosterone kits was stopped or supply problems occurred. Materials and Methods In October 2021, samples were collected from the patients (n=49) who requested the testosterone RIA test. The experiment was conducted by dividing the patient's sample into low concentration (1.0 ng/mL or less), medium concentration (2.0-4.0 ng/mL) and high concentration (6.0 ng/mL or more). The Testosterone RIA test compared and evaluated the validity of Company A kits used in this hospital and those of Company B and C used in other hospitals. The precision, sensitivity, recovery, linearity and correlation were evaluated for each kit. The testosterone RIA test was carried out in accordance with the insert kit manual for each manufacturer. Results As a result of measuring the precision of the intra assay, the Coefficient of Variation (CV) value of the company A kit was high at 11.4% only in the low concentration sample, and in the case of the company B and C kits, the CV value was less than 10% at low, medium, and high concentrations. In the inter-assay precision measurement, the CV value was less than 15% in both A and C kits, but in the case of the B kit, the CV value exceeded 15% at low and medium concentrations. Sensitivity was 0.13 ng/mL for company A, 0.01 ng/mL for company B, and 0.01 ng/mL for company C, and the linearity of all three kits showed excellent linearity. In the case of recovery rate, all of the A, B, and C company kits showed results that were out of 90-110%. In the case of correlation test, when compared with the company A kit currently use in here, the correlation coefficient (R2) value for the company B kit was 0.9508, and for the company C kit was 0.9352 Conclusion As a result, there was a slight difference in precision at the low concentration sample. The correlation test showed an excellent correlation coefficient. However, it was difficult to secure samples of various concentrations because there were not many tests of testosterone requested at this hospital. So, additional experiments should be carried out by acquiring samples of various concentrations on each laboratory later.

A study on the development of analytical method for zinc pyrithione in cosmetics (화장품 중 zinc pyrithione 분석방법 개발에 대한 연구)

  • Jung, Jung-sul;Bae, Kyeong-mi;Son, Seung-hwan;Park, Jung-woo;Kim, Ji-hyun;Hong, Sung-taeg;Sun, Yle-shik
    • Analytical Science and Technology
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    • v.28 no.3
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    • pp.160-167
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    • 2015
  • This study aims to develop a new analytical method to detect zinc pyrithione, the ingredient of cosmetics appointed as restricted ingredients and used as preservatives.. The analytical method was based on data gathered from the relevant literature. Information about the amounts of these ingredients was researched in order to select the base-matrix materials used to validate the analytical method. After selecting and preparing the base-matrix materials, the analytical method was validated by method validation procedures. The analytical method was verified first by inter-laboratory validation and then through analyzing the cosmetics sold in the market. Based on the results of this study, guidelines are proposed for the analysis of restricted ingredients in cosmetics, which will provide a method to test the cosmetics circulating in the Korean market. The use of the proposed guidelines will increase the quality of the cosmetics as well as the safety of human health, which will enhance the competitiveness of the Korean cosmetics industry and lead to an increase in the exportation of cosmetics.

A Study on the Interrelation Between Serum Cholesterol level and Essential Hypertension, Liver Disease and Body weight (혈청(血淸)콜레스테롤 농도(濃度)와 본능성고혈압(本態性高血壓), 간기능장애(肝機能障碍) 및 체중(體重)과의 상관관계(相關關係)에 대한 검토(檢討))

  • Kim, Myung-Hae
    • The Journal of the Korean life insurance medical association
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    • v.2 no.1
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    • pp.135-142
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    • 1985
  • For the past 10 years, the socioeconomic status of our country was markedly improved. Accordingly, our foodintake patterns and other alt parts are preparing to blance with developed countries. Especially, be westernizing or improving our foodintake patterns, we intake much fat diet(animal food) while our physical activities decrease and alcohol consumtion's population, smoking population gradually increase. For such reasons, the population of obese tendency and cardiovascular diseases are increased. According to recent reports, among all death causes in our country, cardiovascular diseases(hypertension, hypertensive cardiovascular diseases, ischemic heart diseases) occupyd top rank, we know. I(the author) studied the inter-relation between serum cholesterol level which is the important factor of the cardiovascular diseases and essential hypertension liver diseases, hyperglycemia, some cardiac problems which are main decline causes in life insurance's medical assessment, and body weight distribution. Studied samples were selected on 4,313 cases(male; 1,791, female; 2,522) who were tested liver function test from June, 11th, 1980 to Dec., 31st, 1983 on our medical department's laboratory. I selected two groups in those cases: one group was serum cholesterol level 180mg/dl over(11% of whole LFT examed cases: No=502 cases), the other group was serum cholesterol level 120-160mg/dl(No= 502 cases). For convenience, the group of serum cholesterol level 180mg/dl over was "A" the other group was "B", I described. All examed persons of LFT were resident m Tae-Jon city in that time. On the result, 1) Decline rate is 10.5% on the "A" group, 5.9% on the "B" group. "A" group reveals 1.8 times higher than "B" group. 2) On decline causes, Essential hypertension is 4.0 times higher on the "A" group than "B", liver function's abnormalities are 2.0 times higher on "A" group than "B" and other diseases are same on "A" and "B". On the "A" group, essential hypertension is considerably higher than "B" group. 3) On the body weight distribution, the cases of 70kg(B.W.) over is 19.7% on "A", 10.6% on "B" group. Obese tendency is 1.8 folds higher on "A" group than "B" group. Studing the result, we find high serum cholesterol concentration is closely related with essential hypertension, obese tendency and liver function's abnormalities on the life insurance's medical examination part, also. On the future, we will more carefully consider the serum cholesterol concentration on our medical examnination and assessment of life insurance, I think.

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Development and Validation of a Simultaneous Analytical Method for the Detection of Mefentrifluconazole and Triticonazole Fungicide in Agricultural Crops (농산물 중 메펜트리플루코나졸 및 트리티코나졸 살균제의 동시 분석법 개발 및 검증)

  • Park, Ji-Su;Lee, Han Sol;Lee, Su Jung;Shin, Hye-Sun;Shim, Jae-Han;Yun, Sang Soon;Jung, Yong-hyun;Oh, Jae-Ho
    • Korean Journal of Environmental Agriculture
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    • v.39 no.2
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    • pp.130-137
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    • 2020
  • BACKGROUND: Mefentrifluconazole and triticonazole are the triazole fungicides. The maximum residue levels for agricultural products need to be set up. Therefore, development of the official analytical method for determination of mefentrifluconazole and triticonazole residues from agricultural crops was necessary due to safety management, and then a simultaneous analytical method was developed for the determination of mefentrifluconazole and triticonazole in agricultural crops. METHODS AND RESULTS: Samples were extracted using acetonitrile and purified using dispersive solid phase extraction, and then detected with liquid chromatograph-tandem mass spectrometry (LC-MS/MS). Matrix-matched calibration curves (0.0025-0.25 ㎍/mL) were linear into a sample extract with r2>0.99. For validation, the recovery test was carried out at three fortification levels (LOQ, 10 LOQ and 50 LOQ) from agricultural samples. The results for mefentrifluconazole and triticonazole ranged between 92.3 to 115.3% and 91.4 to 108.5%, respectively and RSD (relative standard deviation) values were also below 6.0%. Furthermore, inter-laboratory was conducted to validate the method. CONCLUSION: All values were corresponded with the criteria ranges requested by both the CODEX (CAC/GL 40-1993, 2003) and MFDS guidelines (2016). Therefore, the proposed method can be used as an official analytical method for determination of mefentrifluconazole and triticonazole (triazole fungicides) in the Republic of Korea.

Improvement of Analytical Method for Total Polysaccharides in Aloe vera Gel (알로에 베라(Aloe vera) 겔 중 총 다당체 시험법 개선)

  • Lee, Young-Joo;Kim, Yun-Je;Leem, Dong-Gil;Yoon, Tae-Hyung;Shin, Ji-Eun;Yoon, Chang-Yong;Kim, Jung-Hoon;Park, Mi-Sun;Kang, Tae-Seok;Jeong, Ja-Young
    • Journal of Food Hygiene and Safety
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    • v.27 no.3
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    • pp.271-276
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    • 2012
  • This study intented to standardize the method for total polysaccharide, which is a functional marker for aloe vera gel in Korea. We used four lyophilized raw materials and commercial aloe gel products, certified as Health Functional Food by Korea Food and Drug Administration, including powder, solution, jelly, tablet and capsule, to optimize the analytical condition of dialysis and phenol-sulfuric acid reaction in polysaccharide analysis. The optimal conditions for polysaccharide analysis included 1 L water for dialysis and change 3 times for 24hr against 25 mL prepared sample solution. Validation test showed lower than 5% of coefficient of variation(CV) in intra-, interday validation in lyophilized raw materials and 4 types of commercial products. In inter-person and inter-laboratory validation with 4 persons from 4 different laboratories, CV(%) were 5.50 and 6.64 respectively. The linearity of polysaccharide analysis was assessed using 5 serial concentration of lyophilized raw materials(0.1, 0.2, 0.3, 0.4, 0.5%(w/v)). The results showed $R^2{\geq}0.995$ of high linearity. In the commercial aloe vera gel products, the results of reproductivity showed lower than 7.08% and revealed that the standardized method from this study ensured high precision for polysaccharide analysis.

Evaluation of Community Land Model version 3.5-Dynamic Global Vegetation Model over Deciduous Forest in Gwangneung, Korea (광릉 활엽수림에서 Community Land Model 3.5-Dynamic Global Vegetation Model의 평가)

  • Lim, Hee-Jeong;Lee, Young-Hee;Kwon, Hyo-Jung
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.12 no.2
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    • pp.95-106
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    • 2010
  • The performance of Community Land Model version 3.5 - Dynamic Global Vegetation Model (CLM-DGVM) was evaluated through a comparison with the observation over temperate deciduous forest in Gwangneung, Korea. Influence of plant phenology, composition of plant functional type, and climate variability on carbon exchanges was also examined through sensitivity test. To get equilibrium carbon storage, the model was run for 400 years driven by the observed atmospheric data at the deciduous forest of the year 2006. We run the model for 2006 with the equilibrium carbon storage at Gwangneung forest and compared the model output with the observation. A comparison of leaf area index (LAI) between the model and observation indicated that the simulated phenology poorly represented the timing of budburst, leaf-fall, and evolution of LAI. Senescence of the phenology was delayed about four weeks and the simulated maximum LAI (of 5.8 $m^2$ $m^{-2}$) was greater than the observed value (of 4.5 $m^2$ $m^{-2}$). The overestimated LAI contributed to overestimation of both gross primary productivity (GPP) and ecosystem respiration $(R_e)$ through increased photosynthesis and foliar autotropic respiration $(R_a)$, respectively. Despite the discrepancy between the simulated and observed LAI, the simulated tree carbon storage amounts were comparable with the reported values at the site. Change in plant phenology from the simulated to the observed reduced more than six weeks of the plant growth period, resulting in the decreased amount of GPP and $R_e$. These values, however, were still higher (~10% of GPP and 40% of $R_e$) than the observed values. The effect of change in plant functional type composition (from dominant temperate deciduous forest to the coexistence of temperate deciduous and needle leaf forests) on the estimated amount of GPP and $R_e$ was marginal. The influence of climate variability on carbon storage amounts was not significant. The simulated inter-annual variation of GPP and $R_e$ from 1994 to 2003 depended on annual mean air temperature and total radiation but not on precipitation. Other deficiencies of CLM3.5-DGVM have been discussed.