• Title/Summary/Keyword: $PM_{2.5}/PM_{10}$ ratio

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The Evaluation of Image Quality in Gradient Echo MRI of the Pancreas : Comparison with 2D T1 FFE and 3D T1 THRIVE Imaging (췌장 경사자기장에코 자기공명영상에서 영상의 질 평가)

  • Goo, Eun-Hoe
    • Journal of the Korean Society of Radiology
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    • v.10 no.2
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    • pp.73-79
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    • 2016
  • The purpose of this analysis is to compare 2D T1 FEE and 3D T1 THRIVE for demonstration of the pancreas. A total of 85(45 men, 40 women; 58 years) PACS network datum were analysis clinically indicated pancreas MRI at 1.5 T. The SNRs and CNRs of 3D T1 THRIVE(SNR: $46.42{\pm}0.67$, CNR: $28.16{\pm}0.50$) showed significantly higher values than those from 2D T1 FEE(SNR: $53.84{\pm}1.20$, CNR: $35.48{\pm}0.70$), p<0.05, The image quality of the 3D T1 THRIVE($2.63 {\pm}0.14$) was significantly superior to that with the 2D T1 FEE($2.2{\pm}0.05$), but 3D T1 THRIVE revealed several artifacts resulting in poor quality. In conclusion, The 3D T1 THRIVE technique with a 1.5 T resulting in improved SNRs, CNRs and image quality was demonstrated.

The Behaviour of Dust Concentrations During Sand Storm in Seoul Area (황사기간 중 PM2.5, PM10, TSP 농도 특성에 관한 연구)

  • Kim, Min-Young;Kim, Kwang-Rae;Lee, Min-Hwan;Cho, Seog-Ju
    • Journal of the Korean earth science society
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    • v.24 no.4
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    • pp.315-324
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    • 2003
  • The characteristics of particles were evaluated through the measurement data of PM$_{2.5}$, PM$_{10}$ and TSP instruments located in air quality monitoring stations installed and operated by Seoul Metropolitan city. The data of particulate mass on the filter was collected bv a high volume air sampler during the sand storm period. The number of days of sand storm in Seoul showed a different pattern from 1990 to November 2002, We can see a trend of increased occurrence and duration of sand storms. The ratio of PM$_{10}$ to TSP was shown as 52.9% and 59.4% during the sand storm period in 2000 and 2001. respectively. It was indicated that the particles larger than 10${\mu}$m increased by approximately 10% in sand storm periods compared to no sand storm period. While PM$_{10}$ size fraction reached 71.4% in 2002, the contribution of sand storm to total particulate concentration was estimated to be 11.9% for PM$_{2.5}$, 23.1% for PM$_{10}$, 19% for TSP in 2002, respectively and sand storms highly correlated with annual total particulate concentration.

Studies on Body Fat Ratio and Nutrient Intakes of College Students

  • Lee, Ji-Hyang;Song, Kyung-Hee
    • Nutritional Sciences
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    • v.8 no.1
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    • pp.56-60
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    • 2005
  • The aim of this study researchs status of the nutrient intake between male and female students and the nutrient intake by BMI. This study was done to investigate the body composition and nutrient intakes of 340 college students (170 males, 170 females) in Gyeonggi area. Weight, height, BMI, and blood pressure of these college students were measured Nutrient intake was assessed using the 24-hour recall method, and then calculated using the nutritional evaluation program [CAN Pro 2.0 professional (Korean Nutrition Society, 2002)]. Average height and weight were 176$\pm$5.1 cm, 70.60$\pm$l.l kg in male students and 162.2/$\pm$4.5 cm, 54.4$\pm$7.7 kg in female students respectively. Subjects were divided into three groups by BMI: underweight (less than 18.5), normal weight (18.5 to less than 23), and overweight (more than 23). The ratios of male and female subjects among these groups were 5.3% and 17.6% in underweight, 50% and 65.3% in normal weight, and 44.7% and 17.2% in overweight. Systolic and diastolic blood pressures were 124.0$\pm$1.5 mmHg and 76.1$\pm$14.8 mmHg in males and 1l0.l$\pm$12.9 mmHg and 70.l$\pm$10.8 mmHg in females, all in the normal range. Using nutrient values of the 7th Recommended Dietary Allowanes, the nutrient intake was calculated to Korean RDA (%). Nutrients below 75% Korean RDA were Calcium, Vitamin $B_2$, and Folate and nutrients above 100% RDA were Protein, Fe, Phosphorous, and Vitamin $B_6$. BMI showed positive correlations with body fat (%)(p<0.01) and WHR (p<0.01). Nutritional education is desirable for the improvement of dietary behaviors, body composition and nutrient intake of college students.

Analysis of gonadotropin-releasing hormone (GnRH) test results in girls with precocious puberty (성조숙증 여아에서 생식샘자극호르몬분비호르몬 검사 결과의 분석)

  • Choi, Jung Yun;Kang, Hyun-Ju;Cho, Won Kyoung;Cho, Kyoung Soon;Park, So Hyun;Hahn, Seung Hoon;Jung, Min Ho;Seo, Byung Kyu;Lee, Byung Churl
    • Clinical and Experimental Pediatrics
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    • v.52 no.12
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    • pp.1377-1382
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    • 2009
  • Purpose:The gonadotropin-releasing hormone (GnRH) test results of girls with precocious puberty were analyzed to determine whether this test can efficiently and clearly differentiate between central precocious puberty (CPP) and other disorders. Methods:Clinical and laboratory data of 54 girls with precocious pubertal signs were reviewed. Intravenous GnRH test was performed with blood samples obtained at 0, 30, 60, and 90 minutes. A peak luteinizing hormone (LH) level of ${\geq}5.0IU/L$ was indicative of CPP. Results:Of the 40 girls with CPP, 36 (90.0%), 3 (7.5%), and 1 (2.5%) showed peak LH levels at 30, 60, and 90 minutes, respectively. A percentage of girls whose peak LH ${\geq}5.0IU/L$ up to 30, 60, and 90 minutes was 92.5%, 100%, and 100%, respectively. The peak LH/follicle stimulating hormone (FSH) ratio of girls with CPP was 0.89${\pm}$0.49 and was <1 in 16 of the 40 girls (40.0%). Girls with peak LH/FSH ratio of >1.0 showed higher chronological age (CA) ($8.3{\pm}0.6$ vs. $7.7{\pm}1.0$ years, P=0.033), bone age (BA) ($10.9{\pm}0.8$ vs. $9.7{\pm}1.1$ years, P=0.001), and BA-CA difference ($2.6{\pm}0.7$ vs. $2.0{\pm}0.7$ years, P=0.009) than those of girls with peak LH/FSH ratio of ${\leq}1.0$. Higher percentage of girls with peak LH/FSH ratio of >1.0 showed advanced breast development (${\geq}TannerIII$) (93.7% vs. 41.7%, P=0.001). Conclusion:LH levels after 30 and 60 minutes of intravenous GnRH administration are the most useful for diagnosing CPP in girls.

Characteristics of Fine Particles during Cold Front Passage in Busan, on March 19, 2020 (부산지역 2020년 3월 19일 한랭전선 통과 시 미세먼지 농도 특성)

  • Jeon, Byung-Il
    • Journal of Environmental Science International
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    • v.30 no.6
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    • pp.475-485
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    • 2021
  • This research investigated the characteristics of fine particles during cold front passage in Busan, on March 19, 2020. The cold front speed was 17.4 m/s (about 63k km/hr), moving from the northwest to the southeast, and with a width of about 64 km. The backward trajectory analysis showed that a southern sea air parcel flowed into Busan before the cold front passage, carrying continental materials from China transported into Busan after cold front passage. The PM10 concentration in Busan showed a rapid increase after passing through the cold front, with PM2.5 showing a high concentration during cold front passage. The PM2.5/PM10 ratio was 0.10 - 0.30. When the cold front passed, SO42-, NO3-, Ca2+, NH4+, Na+, and K+ in PM2.5 showed a rapid increase, with SO42- showing the most significant increase. These results indicated that understanding the characteristics of fine particles during cold front passage in Busan could provide insight into establishing a strategy to control urban air quality.

Are colony developmental stages of bumblebee, Bombus terrestris (hymenoptera: apidae) affected by different concentrations of sugar and honey solutions?

  • Imran, Muhammad;Ahmad, Munir;Naeem, Muhammad;Mahmood, Khalid;Nasir, Muhammad;Aslam Sheikh, Umer Ayyaz
    • International Journal of Industrial Entomology and Biomaterials
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    • v.34 no.2
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    • pp.23-31
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    • 2017
  • Bumblebees, more efficient than honeybees, provide important services for pollination especially in tomato, pepper, cucumber, strawberries and other crops grown under tunnel farming or glasshouse conditions to yield maximization. These bees require pollen and nectar to meet their dietary needs and maintain their colony structure, development and reproduction. Keeping in view their economic importance, the effect of five concentrations of sugar and honey solutions (1:1, 1:1.5, 1:2, 2:1,1.5:1) each as alternative to nectar were used to observe their effect on life history parameters of Bombus terrestris. The 1:1 ratio of sugar solution was found most effective followed by 1.5:1, 1:1.5, 1:2 and 2:1 and also more effective of all five concentrations of honey solutions on all three stages of colony development i.e., at colony initiation, colony development and colony maturation stages. At colony initiation stage, early pre-oviposition period ($6.40{\pm}0.97$ days), early emergence of first worker in the first batch ($25.40{\pm}1.21$ days) and maximum numbers of workers ($6.20{\pm}0.24$) emergence in the first batch were observed at 1:1 ratio of sugar solution. Colonies reared on 1:1 ratio of sugar solution reached earlier ($52.13{\pm}1.28$ days) at colony foundation stage with minimum mortality ($3.27{\pm}0.54$ workers). At colony maturation stage, maximum numbers of workers, sexual (males, queens) and maximum mother queen longevity was observed at the same 1:1 ratio of sugar solution. It can be suggested from present study that sugar solution as alternative of nectar at 1:1 ratio was better than other sugar concentration levels and also from those of honey solution.

Validation for SOC Estimation from OC and EC concentration in PM2.5 measured at Seoul (서울 대기 중 PM2.5 내 OC와 EC로부터 SOC 추정방법의 비교 평가)

  • Yoo, Ha Young;Kim, Ki Ae;Kim, Yong Pyo;Jung, Chang Hoon;Shin, Hye Jung;Moon, Kwang Ju;Park, Seung Myung;Lee, Ji Yi
    • Particle and aerosol research
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    • v.16 no.1
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    • pp.19-30
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    • 2020
  • The organic carbon in the ambient particulate matter (PM) is divided into primary organic carbon (POC) and secondary organic carbon (SOC) by their formation way. To regulate PM effectively, the estimation of the amount of POC and SOC separately is one of important consideration. Since SOC cannot be measured directly, previous studies have evaluated determination of SOC by the EC tracer method. The EC tracer method is a method of estimating the SOC value from calculating the POC by determining (OC/EC)pri which is the ratio of the measured values of OC and EC from the primary combustion source. In this study, three different ways were applied to OC and EC concentrations in PM2.5 measured at Seoul for determining (OC/EC)pri: 1) the minimum value of OC/EC ratio during the measurement period; 2) regression analysis of OC vs. EC to select the lower 5-20% OC/EC ratio; 3) determining the OC/EC ratio which has lowest correlation coefficient value (R2) between EC and SOC which is reported as minimum R squared method (MRS). Each (OC/EC)pri ratio of three ways are 0.35, 1.22, and 1.77, respectively from the 1 hourly data. We compared the (OC/EC)pri ratio from 1hourly data with 24 hourly data and revealed that (OC/EC)pri estimated from 24 hourly data had twice larger than 1hourly data due to the low time resolution of sampling. We finally confirmed that the most appropriate value of (OC/EC)pri is that calculated by a regression analysis of 1 hourly data and estimated SOC amounts at PM2.5 of the Seoul atmosphere.

Reduction of Particulate Matters Levels in Railway Cabins in Korea

  • Park, Duck-Shin;Kwon, Soon-Bark;Cho, Young-Min;Park, Eun-Young;Jeong, Woo-Tae;Lee, Ki-Young
    • Journal of Environmental Health Sciences
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    • v.38 no.1
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    • pp.51-56
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    • 2012
  • Objectives: High concentrations of airborne particulate matters (PM) can affect the health of passengers using public transportation. The objectives of this research were to develop a PM control system for a railway cabin and to evaluate the performance of the device under conditions of an actual journey. Methods: This study measured the concentrations of $PM_{10}$ and $PM_{2.5}$ simultaneously in a reference cabin and a cabin with the PM control device. Results: The average $PM_{10}$ concentration in the reference cabin was 100 ${\mu}g/m^3$, and the $PM_{10}$ concentration in the cabin with the control device was 79 ${\mu}g/m^3$. While the overall control efficiency of the control device was 15.4%, reduction was more effective for peak $PM_{10}$ concentration. However, $PM_{2.5}$ levels did not differ greatly between the reference cabin and the cabin with the control device. The ratio of $PM_{2.5}$ to $PM_{10}$ was 0.37. $PM_{10}$ concentrations in cabins were not associated with ambient concentrations, indicating that the main sources of $PM_{10}$ were present in cabins. Additionally, average $CO_2$ concentration in the cabins was 1,359 ppm, less than the maximum of 2,000 ppm set out by the Korean Ministry of Environment's guideline. The $CO_2$ concentration in cabins was significantly associated with the number of passengers: the in-cabin concentration = $23.4{\times}N+460.2$, where N is the number of passengers. Conclusions: Application of the PM control device can improve $PM_{10}$ concentration, especially at peak levels but not $PM_{2.5}$ concentration.

Effect of Feeding Different Ratios of Green Fodder and Straw Supplemented with Wheat Bran on the Performance of Male Crossbred Calves

  • Sahoo, A.;Chaudhary, L.C.;Agarwal, N.;Kamra, D.N.;Pathak, N.N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.1
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    • pp.19-22
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    • 2000
  • Twenty male crossbred calves of about one year of age (average body weight, 196 kg) were distributed in four equal groups following complete randomized design. Wheat bran was supplemented to four different combinations of wheat straw and green fodder (Sorghum vulgare) at 40:60, 30:70, 20:80 and 10:90 ratios (on as fed basis) for the feeding of animals in Group 1, 2, 3 and 4, respectively. The feeding trial was continued for a period of 70 days including one metabolism trial of 6 days collection of feed, faeces and urine sample to determine the intake and utilization of nutrients. The intakes (g/kg $W^{0.75}$) of DM, TDN and CP were $93.0{\pm}1.8$, $55.5{\pm}1.1$ and $9.51{\pm}0.18$ in Group 1; $98.0{\pm}1.8$, $59.6{\pm}1.1$ and $10.33{\pm}0.19$ in Group 2; $98.1{\pm}2.4$, $60.5{\pm}1.5$ and $10.79{\pm}0.26$ in Group 3; and $97.7{\pm}1.7$, $59.1{\pm}1.0$ and $10.78{\pm}0.19$ in Group 4, respectively. The digestibility of nutrients did not differ significantly among the groups. Relatively higher nutrient intake and balances of nitrogen reflected non-significantly high her live weight gain in the later three groups (436, 439 and 464 g, respectively) as compared to Group 1 (400 g). The DM intake remained unchanged by increasing the proportion of green fodder beyond 20:80 ratio and thus was assessed to be satisfactory for optimum productivity in animals.

An Effect on the Properties of High Flowing Concrete by Materials Variations-Focused on Inchon LNG Receiving Terminal #213,214 Tanks- (사용재료의 품질변동이 고유동콘크리트의 특성에 미치는 영향-인천 LNG 인수기지 #213,214-TK를 중심으로-)

  • 권영호;김무한
    • Journal of the Korea Concrete Institute
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    • v.12 no.2
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    • pp.99-107
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    • 2000
  • This research investigates experimentally an effect on the properties of the high flowing concrete to be poured in the under-ground slurry wall of Inchon LNG receiving terminal(#213,214-TK) according to variations of concrete materials. Variables for sensitivity test were selected items as followings. 1) Concrete temperature (3cases), 2) Unit water (5cases), 3) Fineness modulus of fine aggregate (5cases), 4) Particle size of lime stone powder (3cases), 5) Replacement ratio of blast-furnace slag (4cases) and 6) Addition ratio of high range water reducing agent (5cases). And fresh conditions of the super flowing concrete should be satisfied with required range including slump flow(65$\pm$5cm), 50cm reaching time of flow(4~10sec), V-lot flowing time(10~ 20sec), U-box height(min. 300mm) and air content(4$\pm$1%). As results for sensitivity test, considered flow-ability, self-compaction and segregation resistance of the high flowing concrete, material variations and conditions of fresh concrete should be satisfied with the range as follwings. 1) Concrete temperature are 10~2$0^{\circ}C$(below 3$0^{\circ}C$), 2) Surface moisture of fine aggregate is within $\pm$ 0.6%, 3) Fineness modulus of fine aggregate is 2.6$\pm$0.2, 4)Replacement ratio of blast-furnace slag is 45~50% and 5) Addition ratio of high range water reducing agent is within 1%. Based on the specification for quality control, we successfully finished concrete pouring on the under-ground slurry wall having 75,000㎥(#213,214-TK) and accumulated real date in site.