• Title/Summary/Keyword: Mass changes

Search Result 2,182, Processing Time 0.025 seconds

The Study of Sediment Volume Concentration in Liquefied-Layer of Debris Flow (토석류 유동층에서 토사체적 농도 특성에 관한 연구)

  • Kim, Sungduk
    • Journal of the Korean GEO-environmental Society
    • /
    • v.15 no.12
    • /
    • pp.109-115
    • /
    • 2014
  • The purpose of this study is to estimate the sediment volume concentration of the liquified-solid mixture which is included fine sediment fractions, according to the variance of the channel slope and the water supply. The numerical model was performed by using the Finite Differential Element Method (FDM) based on the equation for the mass conservation, momentum conservation and the equation of coarse sediment an fine sediment. In comparison of varying the channel slope, the deeper the channel slope, the inflection point of the sediment concentration was occurred rapidly. In comparison of variance of the water supply, as the water supply increases fluctuation with high sediment concentration. In this situation, debris flow changes to the turbulent flow and the sediment becomes to be floated. In comparison varying the length paved saturated sediment, the longer the length, the high concentration of sediment occurred, for the safety of the slope it is needed to check the possibility of the erosion in the slope by debris flow. The results of this study will provide useful information in predicting of the disaster by the liquified-solid mixture and in prevention of the debris flow with various the slope in the mountain side.

A study on the determination of the number of mobility cluster (적정 이동군집수 결정에 관한 연구)

  • ;Ham, Sung Hun
    • Journal of the Korean Geographical Society
    • /
    • v.30 no.2
    • /
    • pp.120-131
    • /
    • 1995
  • To analyze mobility patterns, this study used three Constraint (Capability Constraint, Coupling Constraint, Authority Constraint) models which were proposed in Dr. Hagerstrand's Time-space theory. This paper shows that three constraint models have some effects upon mobility by age. In this study, Capability Constraint means a certain special constraint that is what we can't do during proceeding basic natural urges like sleep, fare, etc. Coupling constraint is a physical one. Each person limits the action range for staying on a special place in special time. For instance, students have to stay in school so that they have mobility constraints. Authority Constraint is a social one. When we use urban facilities or traffic, we may be controlled by mobility sphere by an agreement or a social position. It is social agreement that the opening hour of a store, the time table of mass-transportation and a social positional control that the personal income, the standard of education. In this study it has been in a process of determination of the cluster number that degree of influences a social constraint to mobility. Considering the mobility constraint of characteristics of space divides urban and rural, people in urban area have higher mobility rate than in rural area. Resuets of determination of the cluster, show similar mobility pattern. People in urban area are connected verity of mobility which related to urban space structures with determination of cluste-number. That is to say, mobility patterns can be changed by space charactcristics. Constraints by sex and age are also social constraints and they are influenced by mobility patterns. For instance, females at the age of twenties have similar mobility pattern to the same age male but they have sudden changes after thirty's age. Male entertains a similar pattern without restriction of age. That is to say, management by sex as a social constraint affects mobility. To establish more realistic traffie policy, mobility formation should be reflected to the space in a view of social-behavioral science. To embody this, some problems should be investigated as follows. 1. As a problem of methodology, if sufficient samples ensured, we could subdivide clusters and could open up a new method of analyzing the mobility clusters by using the neuro-network. 2. Extracting actions connected with mobility and finding life cycle which is classified by daily cluste-characteristics, suitable counterproposal could be presented to the traific policy.

  • PDF

Rapidly Increasing Prevalence of Obesity and Their Confident Determinants in Korea

  • Lee, Jung-Su;Kawakubo, Kiyoshi;Park, Chun-Man;Akabayashi, Akira
    • Korean Journal of Health Education and Promotion
    • /
    • v.23 no.5
    • /
    • pp.1-11
    • /
    • 2006
  • Objectives: The 2003 WHO/FAO technical report described that Korea has largely maintained its traditional high-vegetable diet despite major social and economic changes, and had lower than expected levels of obesity prevalence than other industrialized countries. However, the prevalence of obesity in Korea has recently been rapidly increasing. The aim of this study was to elucidate the determinants of this rapid growth of obesity prevalence in Korea and to compare the results of national nutrition surveys between Korea and Japan. Methods: The trends of the National Health and Nutrition Survey in Korea instituted every 3 years and that in Japan conducted every year were compared. The results of obesity prevalence defined as more than 25 of the Body Mass Index, the percentage of habitual exercisers and the results of the nutritional surveys were examined from 1992 to 2005 in Korea and from 1992 to 2004 in Japan. Results: The prevalence of obesity in males has been gradually increasing in both Korea and Japan since 1992. Though until 1995 the prevalence of obesity in the Korean male population was less than that in Japan, after 1998 Korea surpassed Japan and a markedly increasing trend was observed. In females, the increasing trend of obesity was slower than males in both Korea and Japan. However, the prevalence of obesity was much higher in Korea compared with that in Japan. The percentage of exercisers was much lower in Korea than in Japan. Although, the definition of an exerciser varies with the survey year in Korea and is different from that in Japan, almost 70% of the population was not regularly engaging in moderate or hard intensity exercise in Korea. From 1995, the total energy intake was increased by 9.8% in Korea but it was decreased by 6.9% in Japan. Presently, the energy intake per capita per day in Korea exceeded that in Japan. Remarkable increases in the intake of meat and poultry, vegetable oils and fats, and milk and dairy products were observed in Korea from 1995 to 2005. On the other hand, these values decreased during the same period in Japan. Conclusion: The prevalence of obesity in Korea is increasing and has surpassed that of Japan. The current trends could be attributed to the low prevalence of habitual exercisers, and an increase in energy intake and the proportion of energy intake from fat.

Flavonoid Component Changes and Antioxidant Activities of Fermented Citrus grandis Osbeck Peel (당유자 과피 발효물의 플라보노이드 성분 변화 및 항산화 활성)

  • Hyon, Jae-Seok;Kang, Sung-Myung;Han, Sang-Won;Kang, Min-Cheol;Oh, Myung-Cheol;Oh, Chang-Kyung;Kim, Dong-Woo;Jeon, You-Jin;Kim, Soo-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.38 no.10
    • /
    • pp.1310-1316
    • /
    • 2009
  • In this study, we investigated the change of antioxidant activity and flavonoid contents by fermentation of Citrus grandis Osbeck peel (CGP) using the Saccharomyces cerevisiae (KCCM35053), comparing to unfermented CGP. Total flavonoid content in the fermented Citrus grandis Osbeck peel (FCGP) was 3,768 g/100 g sample and higher than that of CGP. The antioxidant activities of FCGP was determined by DPPH, hydroxyl, alkyl radicals, and hydrogen peroxide scavenging assays. FCGP showed higher activities than CGP in all scavenging assays. The $IC_{50}$ values of FCGP were 261.3 ${\mu}g$/mL for DPPH; 1,474 ${\mu}g$/mL for hydroxyl; 90.9 ${\mu}g$/mL for alkyl and 1,195 ${\mu}g$/mL for $H_2O_2$ in respective scavenging assays. Flavonoid compositions of both samples were determined by liquid chromatography/mass spectrometry (LC/MS). In the spectrum FCGP was similar to CGP in the contents of neohesperidin, naringin and an unknown No. 7 compound, but some unknown compounds (No. 1, 2, 4, 5, 6) were higher than CGP in each flavonoid contents. Therefore, the fermentation of CGP could increase the contents of unknown compound and improved antioxidant activities.

Defatted Grape Seed Extracts Suppress Adipogenesis in 3T3-L1 Preadipocytes (포도씨 탈지박 추출물 처리가 3T3-L1 Preadipocyte 내 지방 생성에 미치는 영향)

  • Cho, Young-Min;Lee, Seon-Mi;Kim, Young-Hwa;Jeon, Geon-Uk;Sung, Jee-Hy;Jeong, Heon-Sang;Lee, Jun-Soo
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.39 no.6
    • /
    • pp.927-931
    • /
    • 2010
  • The objective of this study was to evaluate the effect of defatted grape seed extract (DGSE) on adipocyte differentiation in 3T3-L1 preadipocytes. DGSE at 100 ${\mu}g$/mL significantly suppressed lipid accumulation and glycerol-3-phosphate dehydrogenase activity in hormonally stimulated adipocytes, an indicator of adipocyte differentiation. In order to understand the anti-adipogenic effects of DGSE, the changes in the expression of several adipogenic transcription factors including peroxisome proliferator-activated receptor (PPAR) $\gamma$, CCAAT/enhancer-binding protein (C/EBP) $\alpha$ and $\beta$ were investigated using immunoblotting. DGSE suppressed the expression of PPAR$\gamma$, C/EBP$\alpha$, and C/EBP$\beta$ proteins compared with control adipocytes in a dose-dependent manner. This results indicated that DGSE may alter fat mass by directly affecting adipogensis in maturing preadipocytes and thus may have applications for the treatment of obesity.

Effects of Nutrition Education Providing School Lunch by Personalized Daily Needed Food Exchange Units for Adolescent Athletes in Jeonbuk Province (전북지역 청소년 운동선수 대상 하루 필요 식품군 수 맞춤 점심급식을 병행한 영양교육 효과)

  • Ko, Kang-Mo;Kim, Sook-Bae
    • Korean Journal of Community Nutrition
    • /
    • v.21 no.1
    • /
    • pp.25-36
    • /
    • 2016
  • Objectives: The purpose of this study was to investigate effects of nutrition education providing school lunch by personalized daily needed food exchange units using Food Exchange System for adolescent athletes. Methods: The subjects were 60 sports high school students (educated group, 30 vs. noneducated group 30). Nutrition education was provided for 4 weeks (40 min/lesson/week). In addition, personalized school lunch was served for 4 weeks, nutrition education period. The personalized lunch were provided Food Exchange Units according to personalized daily needed energy. The lessons were '5 Major nutrients, functions and foods', 'My daily needed energy and food exchange units by Food Exchange System', 'My meal plan by food exchange units according to my daily needed energy' and 'Smart choice of healthy snacks and eating outs'. After nutrition education, we examined the differences in anthropometric characteristics, nutrition knowledge, dietary attitude and dietary intake between the educated and the non-educated group. Results: We observed improvements in lean body mass in the educated group. With regard to nutrition knowledge, there were improvements in 'Functions of vitamins', 'Functions of minerals', 'Foods of fat', 'Foods of vitamin', and 'Foods of mineral' in the educated group. In relation to dietary attitude, there were improvements in 'Taking a meal with family and friend', 'Taking a meal at ease', 'Taking a meal with kimchi and vegetables', 'Taking a meal with three kinds of side dishes', 'Priority of choosing snacks' and 'Type of snacks' in the educated group. With regard to dietary intakes according to Dietary Reference Intakes for Koreans, there were improvements in intakes levels of fiber, vitamin A, vitamin C, folate, calcium, iron and zinc. The index of nutrition quality, as indicated by nutrition adequacy ratio also improved in the educated group. Conclusions: These results showed that a nutrition education program providing education lessons and personalized school lunch by food exchange units according to daily needed energy showed positive changes in nutrition knowledge, dietary attitude and dietary intake of adolescent athletes. Nutrition education program providing personalized school lunch by Food Exchange Units may improve dietary behaviors and dietary intakes of adolescents.

Analysis of Mass Transport in PEMFC GDL (연료전지 가스확산층(GDL) 내의 물질거동에 대한 연구)

  • Jeong, Hee-Seok;Kim, Jeong-Ik;Lee, Seong-Ho;Lim, Cheol-Ho;Ahn, Byung-Ki;Kim, Charn-Jung
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.36 no.10
    • /
    • pp.979-988
    • /
    • 2012
  • The 3D structure of GDL for fuel cells was measured using high-resolution X-ray tomography in order to study material transport in the GDL. A computational algorithm has been developed to remove noise in the 3D image and construct 3D elements representing carbon fibers of GDL, which were used for both structural and fluid analyses. Changes in the pore structure of GDL under various compression levels were calculated, and the corresponding volume meshes were generated to evaluate the anisotropic permeability of gas within GDL as a function of compression. Furthermore, the transfer of liquid water and reactant gases was simulated by using the volume of fluid (VOF) and pore-network model (PNM) techniques. In addition, the simulation results of liquid water transport in GDL were validated by analogous experiments to visualize the diffusion of fluid in porous media. Through this research, a procedure for simulating the material transport in deformed GDL has been developed; this will help in optimizing the clamping force of fuel cell stacks as well as in determining the design parameters of GDL, such as thickness and porosity.

Fermentation of wheat bran through lactic acid bacteria: Changes in flavor components and free amino acids and potential applications in baking (밀기울의 유산균 발효: 향기성분 및 유리아미노산 변화를 통한 제빵 소재로서의 가능성)

  • Na, Yerim;Park, Sung Hoon
    • Korean Journal of Food Science and Technology
    • /
    • v.52 no.5
    • /
    • pp.524-528
    • /
    • 2020
  • The aim of this study was to enhance the use of wheat bran in lactic acid bacteria (LAB) fermentation. LAB fermentation of wheat bran and the flavor components and amino acids of fermentation products were analyzed using gas chromatography-mass spectrometry (GC/MS) and high-performance liquid chromatography (HPLC). The results showed that total flavor components increased by 93% and 73% in the animal-based LAB mixture (T2) and plant-based LAB mixture (T3), respectively, after fermentation. Among these components, 2,3-butanedione (diacetyl), known for its buttery flavor, was detected at concentrations of 18.44 ng/g (T2) and 16.95 ng/g (T3). Levels of hexanal and nonanal, which causes off-flavor components in wheat bran, dramatically decreased after T2 fermentation; similarly, levels of total free amino acids decreased by 37.6% (T2) and 36.7% (T3) after fermentation. This may explain why some components were bound to volatile compounds during LAB fermentation. These results suggest that LAB-fermented wheat bran is a potential value-added food material.

Effects of Aerobic Training Plus Diet on Blood Lipids and Apolipoproteins in Obese Children (유산소 트레이닝과 식사조절 병행이 비만아동의 혈중지질과 아포지단백에 미치는 효과)

  • Park, Tae-Gon
    • Journal of Life Science
    • /
    • v.18 no.10
    • /
    • pp.1384-1389
    • /
    • 2008
  • The purpose of this study was to find out the effects of aerobic training plus diet on blood lipids and apolipoproteins (Apo) in obese children. Sixteen healthy obese boys (ages 10.9; body mass index (BMI) $\geq$95th percentiles for age and sex) participated in this study. The aerobic training program consisted of 40 minutes hiking on a mountain, 60 minute of basketball and football dribbling at an intensity of 60-70% of HRmax, and was performed 5 days a week for 9 weeks. The diet prescription was 2,100 kal/day according to the recommended dietary allowance for 10-12 year old Koreans. All subjects stayed in a training camp for 9 weeks. The results of this study were as follows; Blood lipid profiles including total cholesterol (TC), triglyceride (TG) high density lipoprotein cholesterol (HDL-C) and TC/HDL-C ratio were significantly improved after the 9 week program, but there was no significant change in low density lipoprotein (LDL-C). Apolipoprotein profiles, Apo AI, AII, B, CII and CⅢ were all significantly decreased after the 9 week program, but there were no significant difference in Apo AI/AII ratio and Apo B/AI ratio. These results indicate that aerobic training together with a healthy diet can induce positive changes on blood lipid profiles, Apo AII, B and CII in obese children.

Effects of Aerobic Exercise Plus Lifestyle Modification Program on Obese-Induced Metabolic Syndrome in Obese Adolescent Girls (유산소운동과 생활양식 프로그램 병행이 비만 여자청소년의 비만유래 대사증후군에 미치는 효과)

  • Park, Chan-Ho;Park, Tae-Gon
    • Journal of Life Science
    • /
    • v.19 no.2
    • /
    • pp.198-205
    • /
    • 2009
  • The purpose of this study was to find out the effects of a 12-week aerobic exercise plus lifestyle modification on obese-induced metabolic syndrome in obese adolescent girls. A total of 52 obese adolescent girls (13-14 years old; body mass index (BMI) ${\geq}$95th percentiles for age and sex) purposely assigned to aerobic exercise group (AEG, n=15), aerobic exercise plus lifestyle modification group (ALG, n=18), or control group (CG, n=19). The AEG completed 12 weeks of walking exercise (30-60 min/day, 65-75% HRmax, 6 days/week), the ALG completed 12 weeks of walking exercise (30-60 min/day, 65-75% HRmax, 6 days/week) and behavior modification (60 min/day, 1 day/week), and the CG continued their normal life. The presence of the metabolic syndrome and component risk factors were determined before and after 12-week programs. The total prevalence of the metabolic syndrome was 48.1% in this sample (25/52) of participants at baseline. After the programs the prevalence of the metabolic syndrome was improved in the AEG and ALG 33.3, 27.8%, respectively. Group analyses showed significant difference in risk factors of the metabolic syndrome such that the AEG and ALG had significantly greater improvements in waist circumference, triglycerides, blood glucose and systolic blood pressure than the CG, while there were no significant difference in HDL cholesterol and diastolic blood pressure. Also there was no group difference between AEG and ALG in all measured metabolic risk factors after the programs. These results indicate that the positive changes of the ALG were not associated with lifestyle modification (behavior modification) but associated with aerobic exercise. However, long-term follow up studies are necessary to clarify the additive effect of the behavior modification on the metabolic syndrome.