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A Study on the Comparison of Methods for the Measurement of Hydrocarbon Dew Point of Natural Gas (천연가스의 탄화수소 이슬점 측정방법 비교 연구)

  • Lee, Kang-Jin;Ha, Young-Cheol;Her, Jae-Young;Woo, Jin-Chun;Kim, Yong-Doo;Bae, Hyun-Kil
    • Korean Chemical Engineering Research
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    • v.53 no.4
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    • pp.496-502
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    • 2015
  • Hydrocarbon dew point(HCDP), a property which is the most generally used for describing natural gas condensation, is a very important parameter of natural gas quality specifications. HCDP is strongly influenced by the concentration of the heavier hydrocarbon components, especially $C_6+$, so, along with compliance with gas quality specifications, build up of procedures for obtaining accurate HCDP is essential for gas transmission company, because hydrocarbon condensation present may cause serious operational and safety problems. This study has been carried out in an attempt to measure HCDP accurately by the automatic hydrocarbon dew point meter under the actual field conditions. Measured HCDP also has been compared with calculated HCDP using the composition determined by gas chromatograph and industry accepted equation of state at multiple pressures, along with the cricondentherm. The test results are 1) the automatic hydrocarbon dew point meter was able to measure stable HCDP continuously 2) the automatic hydrocarbon dew point meter has been performed reference measurement by pure propane with a known dew point from literature, and 3) A meaningful differences was observed when comparing the automatic hydrocarbon dew point meter and gas chromatograph results for synthetic standard gas mixtures and real gas mixtures.

Correlation and influencing factors on oral health awareness, oral health behavior, self-esteem and OHIP-14 in childcare teachers (일부 보육교사들의 구강건강인식, 구강건강행위, 자아존중감 및 OHIP-14와의 연관성과 영향요인)

  • Lee, Sung-Lim;Kwag, Jung-Suk;Choi, Jeong-Hee
    • Journal of Korean society of Dental Hygiene
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    • v.15 no.2
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    • pp.261-269
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    • 2015
  • Objectives: The purpose of the study is to investigate the correlation and influencing factors of oral health awareness, oral health behaviors, self-esteem and OHIP-14. Methods: A self-reported questionnaire was filled out by 313 childcare teachers in Jeonnam from June 4 to 14, 2013. The questionnaire consisted of 3 questions of general characteristics, 4 questions of occupation, 1 question of oral health education experience, and 1 question of oral health education participation. The instrument for awareness and behavior of oral health were modified and consisted of 10 questions of awareness and 10 questions of behavior by Likert 5 scale. Cronbach's alpha was 0.718 in awareness and 0.812 in behavior. Instrument for self-esteem was modified from Rosenberg. Self-esteem questionnaire consisted fo 5 questions of positive answers and 5 questions of negative answers by Likert 5 scale. Cronbach's alpha in self esteem was 0.846 in the study. Oral Health Impact Profile-14(OHIP-14) was adapted from Slade by Likert 5 scale and consisted fo 14 questions. Cronbach's alpha was 0.934 in the study. Data were analyzed by chi square test, t-test, one way ANOVA, Scheffe multiple range test, Pearason's correlation test, and stepwise multiple regression test. Results: There were positive correlations between oral health awareness, oral health behavior(r=0.502), and self-esteem(r=0.332), but negative correlations with OHIP-14. Oral health behavior showed positive correlations with self-esteem(r=0.230). The factors on oral health awareness were high oral health behavior and self esteem, low OHIP-14, and active participation in education. Self-esteem was closely related to high with high oral health awareness. low OHIP-14, low job satisfaction. Conclusions: Childcare teachers play the very important roles in the development of oral health education program for children and continuous education.

Assessment of Nutritional Status by Estimation of Nutrients and Food Intakes of the Lead Workers in Republic of Korea

  • Kim, Hee-Seon;Song, Ok-Young;Lee, Sung-Soo;Young Hwangbo;Ahn, Kyu-Dong;Lee, Byung-Kook
    • Nutritional Sciences
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    • v.4 no.2
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    • pp.91-97
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    • 2001
  • The purpose of this study was to assess the nutritional status of Korean workers with occupational exposure to lead by estimating nutrients and flood intakes so that we can eventually establish the dietary guidelines to be recommended for the lead workers. Food consumption survey was conducted by a 24-hr recall method with 135 lead workers and 50 non-exposed controls. Food intake data were convened into nutrients intake using computer aided nutritional analysis program. Mean daily energy intake and percentage of recommended daily allowance (RDA) of male lead workers were 2138 local and 87% of RDA while those of control were estimated as 2234 kcal and 91% of RDA. Mean daily intakes of nutrients of male lead workers were 78 g (111% RDA) for protein 502 mg (71% RDA) for calcium, 11.7 mg (97% RDA) for iron, 665 $\mu$g R.E (95% RDA) for vitamin A, 1.39 mg (108% RDA) for thiamin, 1.14 mg (77% RDA) for riboflavin, 15 mg N.E (92% RDA) for niacin and 66 mg (94% RDA) for vitamin C. On average, male lead workers showed significantly lower protein, calcium, iron, sodium, potassium, niacin and vitamin C intakes than control group while cholesterol intake of the male lead workers was significantly higher than that of control group. Intakes of calcium of male lead workers were Less than 75% RDA meaning that nutritional intake of calcium of male lead workers was insufficient and could possibly result in nutritional deficient. Some food groups such as milk, meat and fish must be strongly suggested to improve nutritional status of lead workers. Continuing nutrition monitoring and appropriate nutrition intervention for lead workers most be conducted further.

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Evaluation of Coagulation-UF Process Considering Residual Aluminuim Concentration as Seawater Desalination Pretreatment (해수담수화 전처리 공정으로써 잔류 알루미늄 농도를 고려한 응집-UF 공정 연구)

  • Son, Dong-Min;Kang, Lim-Seok
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.7
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    • pp.495-502
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    • 2013
  • This work was performed to investigate proper condition of coagulation treatment as UF process pretreatment that consider UF permeate flux and residual Al concentration. The coagulant used an alum as $Al_2(SO_4)_3{\cdot}16H_2O$ and PACl (r = 1.5) made this study. The experiment was tested in adjusting conditions such as alum dose, flocculation time and coagulation pH of seawater. Consequently, higher coagulant dose lead to elevation of UF permeate flux while residual aluminium also increased in condition of pH 8.0. The most suitable condition which has a good permeate flux and low residual aluminium, in this works, was coagulant dose of 0.7 mg/L (as Al, alum) and 1.2 mg/L (as Al, PACl) and coagulation pH 6.5. In addition, applying the flocculation time with 1.2 mg/L of PACI reduced. The flocculation time reduced UF permeate flux in using alum.

Production responses of Holstein dairy cows when fed supplemental fat containing saturated free fatty acids: a meta-analysis

  • Hu, Wenping;Boerman, Jacquelyn P.;Aldrich, James M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.8
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    • pp.1105-1116
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    • 2017
  • Objective: A meta-analysis was conducted to evaluate the effects of supplemental fat containing saturated free fatty acids (FA) on milk performance of Holstein dairy cows. Methods: A database was developed from 21 studies published between 1991 and 2016 that included 502 dairy cows and a total of 29 to 30 comparisons between dietary treatment and control without fat supplementation. Only saturated free FA (>80% of total FA) was considered as the supplemental fat. Concentration of the supplemental fat was not higher than 3.5% of diet dry matter (DM). Dairy cows were offered total mixed ration, and fed individually. Statistical analysis was conducted using random- or mixed-effects models with Metafor package in R. Results: Sub-group analysis showed that there were no differences in studies between randomized block design and Latin square/crossover design for dry matter intake (DMI) and milk production responses to the supplemental fat (all response variables, $p{\geq}0.344$). The supplemental fat across all studies improved milk yield, milk fat concentration and yield, and milk protein yield by 1.684 kg/d (p<0.001), 0.095 percent unit (p = 0.003), 0.072 kg/d (p<0.001), and 0.036 kg/d (p<0.001), respectively, but tended to decrease milk protein concentration (mean difference = -0.022 percent unit; p = 0.063) while DMI (mean difference = 0.061 kg/d; p = 0.768) remained unchanged. The assessment of heterogeneity suggested that no substantial heterogeneity occurred among all studies for DMI and milk production responses to the supplemental fat (all response variables, $I^2{\leq}24.1%$; $p{\geq}0.166$). Conclusion: The effects of saturated free FA were quantitatively evaluated. Higher milk production and yields of milk fat and protein, with DMI remaining unchanged, indicated that saturated free FA, supplemented at ${\leq}3.5%$ dietary DM from commercially available fat sources, likely improved the efficiency of milk production. Nevertheless, more studies are needed to assess the variation of production responses to different saturated free FA, either C16:0 or C18:0 alone, or in combination with potentially optimal ratio, when supplemented in dairy cow diets.

Endoparasites of Small Mammals in Edo State, Nigeria: Public Health Implications

  • Isaac, Clement;Igbinosa, Benjamin Igho;Ohiolei, John Asekhaen;Osimen, Catherine Eki
    • Parasites, Hosts and Diseases
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    • v.56 no.1
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    • pp.93-100
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    • 2018
  • Some small mammals occur as household pests and harbour a number of parasites that could be of public health importance. This study profiled the helminth and protozoan parasites in trapped small mammals within and around human dwelling places (houses) located across 4 major towns (Auchi, Benin, Ekpoma, and Uromi) and environs in Edo state, Nigeria. Six genera (Apodemus sp., Crocidura sp., Mastomys natalensis, Mus musculus, Rattus sp., and Sorex sp.) were identified from 502 trapped small mammals. Overall, M. musculus (71.9%) and Rattus rattus (20.1%) were the most frequently trapped. In total, on examination of blood, gastrointestinal contents, and brain tissues, 12 helminth taxa (Angiostrongylus sp., Aspicularis sp., Capillaria sp., Gongylonema sp., Heterakis spumosa, Hymenolepis diminuta, Hymenolepis nana, Mastophorus muris, Moniliformis moniliformis, Nippostrongylus brasiliensis, Strongyloides sp., Trichosomoides sp., and Trichuris sp.), and 6 protozoan parasites (Babesia sp., Trypanosoma lewisi, Plasmodium sp., Eimeria sp., Isospora sp., and Toxoplasma gondii) were isolated. Most prevalent helminths with relatively heavy mean intensity were Strongyloides sp. and Heterakis spumosa, while Plasmodium, Eimeria, and Isospora were the most prevalent protozoan parasites. Generally, intrinsic factors like sex and age had marginal influence on the rate and burden of infection in M. musculus and R. rattus. Although the infection rate and prevalence of zoonotic parasites were low, they were largely recovered in rodents from Ekpoma. This study elucidates the public health implication of the presence of zoonotic parasites in these small mammals.

Predicting Organic Matter content in Korean Soils Using Regression rules on Visible-Near Infrared Diffuse Reflectance Spectra

  • Chun, Hyen-Chung;Hong, Suk-Young;Song, Kwan-Cheol;Kim, Yi-Hyun;Hyun, Byung-Keun;Minasny, Budiman
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.4
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    • pp.497-502
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    • 2012
  • This study investigates the prediction of soil OM on Korean soils using the Visible-Near Infrared (Vis-NIR) spectroscopy. The ASD Field Spec Pro was used to acquire the reflectance of soil samples to visible to near-infrared radiation (350 to 2500 nm). A total of 503 soil samples from 61 Korean soil series were scanned using the instrument and OM was measured using the Walkley and Black method. For data analysis, the spectra were resampled from 500-2450 nm with 4 nm spacing and converted to the $1^{st}$ derivative of absorbance (log (1/R)). Partial least squares regression (PLSR) and regression rules model (Cubist) were applied to predict soil OM. Regression rules model estimates the target value by building conditional rules, and each rule contains a linear expression predicting OM from selected absorbance values. The regression rules model was shown to give a better prediction compared to PLSR. Although the prediction for Andisols had a larger error, soil order was not found to be useful in stratifying the prediction model. The stratification used by Cubist was mainly based on absorbance at wavelengths of 850 and 2320 nm, which corresponds to the organic absorption bands. These results showed that there could be more information on soil properties useful to classify or group OM data from Korean soils. In conclusion, this study shows it is possible to develop good prediction model of OM from Korean soils and provide data to reexamine the existing prediction models for more accurate prediction.

Validation of a Rodent Nose-only Exposure System for Inhalation Toxicity Evaluation of Cigarette Smoke (담배 흡입독성 평가를 위한 설치류 담배연기노출시스템의 유효화)

  • Sohn, Hyung-Ok;Lee, Hyeong-Seok;Shin, Han-Jae;Park, Chul-Hoon;Yoo, Ji-Hye;Jang, Mi;Hyun, Hak-Chul
    • Journal of the Korean Society of Tobacco Science
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    • v.36 no.1
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    • pp.20-25
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    • 2014
  • As part of a balanced testing battery, subchronic inhalation studies on rats are performed to ensure that proposed cigarette modifications do not increase the toxicity of smoke and to demonstrate any instances where a modification may actually contribute to harm reduction. For subchronic inhalation studies with aerosols, the OECD suggests an exposure regimen of 6 hours/day (OECD Guideline 413, 1981), but alternative regimens have also been published: 1 hour/day and $2{\times}1$ hour/day. The aim of this study was to validate a rodent nose-only exposure system for the assessment of inhalation toxicity of cigarette smoke. In this study, cigarette smoke exposure system is consisted of cigarette smoke generator, smoke concentration adjusting system, and 20-port nose-only exposure system. Male SD rats were exposed for 35 days ($2{\times}1$ hour/day) to 3R4F Reference cigarette smoke and analysed major monitoring items of OECD Gudeline 413. WTPM, was measured in the test atmosphere, respiratory function (Buxco Biosystems) during exposure, postexposure urinary exposure biomarkers and alveolar neutrophiles in BAL fluid (Day 35) were evaluated. Validation demonstrated steady WTPM ($257{\pm}20ug/L$, $502{\pm}27ug/L$) and spatial uniformity (<10%). Nose port temperature ($22{\sim}26^{\circ}C$ and RH (45~75%) were acceptable over 35 days. Reductions in respiratory rate and minute volume and increase in the neutrophiles in BALF and the urinary exposure biomarkers were observed cigarette smoke dose dependently. This validation and 35-day inhalation study has shown that the rodent nose-only exposure system may be useful in the inhalation toxicity assessment of cigarette smoke.

Comparative Study Using MIC Test for Cefazedone and other First Generation Cephalosporins (1세대 세파계 항생제인 Cefazedone의 MIC Test를 통한 비교 연구)

  • Bok, Hae-Sook;Kim, Myung-Min;Choi, Kyung-Eob
    • Korean Journal of Clinical Pharmacy
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    • v.5 no.2
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    • pp.13-16
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    • 1995
  • The Minimum Inhibitory Concentration (MIC) of a first-generation cephalosporin derivative, Cefazedone (CZD; $PAZERON^R$ inj.) was determined by the two-fold serial agar dilution method. The in-vitro antibacterial activity of CZD against a wide variety of clinical isolates was compared with those of other first generation cephalosporins such as Methylol Cephalexin (CEX), Cefazolin (CEZ), Cefadroxil (CDX), Cephradine (CED), Ceftezol (CTZ) and one of second generation cephalsporin antibiotics, Cefotaxime (CTX). CZD had the most potent inhibitory effect against Gram-positive strains, when compared to the first-generation cephalosporin antibiotics tested in this study and CTX. The geometric MIC mean of CZD for Gram-positive strains was calculated as 0.386 kg/m{\ell}$, and those of CEX, CEZ, CDX, CTZ, CED, and CTX were 6.073, 0.894, 3.399, 0.748, 7.884 and 1.502 $kg/m{\ell}$, respectively. In addition, the geometric mean of CZD for staphylococclJs aureus strains was obtained as 0.340 $kg/m{\ell}$ and those of CEX, CEZ, CDX, CTZ, CED, and CTX 6.145, 0.534, 4.126, 0.442, 10.51, and 2.500 $kg/m{\ell}$, respectively. Against Gram-negative strains, CZD showed better antibacterial activity than CEZ, CDX, CTZ, and CED.

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Genetic and Phenotypic Evaluation of Milk and Fat Production Traits and Their Interrelationship in (Zebu×European) Crossbred Cattle Using Parent Group Mixed Model

  • Singh, D.;Yadav, A.S.;Dhaka, S.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.9
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    • pp.1242-1246
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    • 2003
  • Data pertained to 335 crossbred cows comprising of 1/2 Friesian (F) + 1/2 Hariana (H), 1/2 F + 1/4 Jersey (J) + 1/4 H, 1/2 F + 1/4 Brown Swiss (BS) + 1/4 H, 1/2 F + 1/4 Red Dane (R) + 1/4 H, FR (I) and FRH (I) genetic groups extending over a period of 21 years (1970-1990) maintained at Animal Farm of CCS HAU, Hisar. The averages for first lactation milk yield was $2,486.24{\pm}80.26kg$ and peak yield of first three lactation were $11.35{\pm}0.72kg$, $13.97{\pm}0.60kg$ and $16.02{\pm}0.42kg$, respectively. The lifetime milk production was observed as $11,305.16{\pm}1,004.52kg$ in crossbred cattle. The average first lactation fat yield was observed as $102.06{\pm}0.01kg$ and peak fat yield of first three lactation were $0.458{\pm}0.01$, $0.490{\pm}0.01$ and $0.500{\pm}0.02kg$, respectively. The lifetime fat production was estimated as $502.31{\pm}45.90kg$. LTMP and LTFP had reasonably good additive genetic variance which could be exploited either through mass selection/combined with family or pedigree selection. FLMY, peak yields and LTMP had significant positive phenotypic correlation with FLFY and LTFP and the correlation at the genetic level were also higher and positive for these traits. Finally, peak week milk yield of first lactation (PMY1) was the earliest available trait having desirable and significant correlation at phenotypic and positive at genetic level with FLFY, PFY1 and PFY2, PFY3 and LTFP and selection for this trait will help in early evaluation of sires and dams and will increase genetic advancement per unit of time.