• Title/Summary/Keyword: Water mass changes

Search Result 248, Processing Time 0.027 seconds

Trace Metals Characterization of Respirable Dust during Yellow Sand Phenomena in Seoul Area (서울지역의 황사발생시 호흡성 분진 중 미량원소의 특성 평가)

  • 신은상;선우영
    • Journal of environmental and Sanitary engineering
    • /
    • v.17 no.1
    • /
    • pp.41-51
    • /
    • 2002
  • This research was carried out using Anderson air sampler which were set up on the roof of the Engineering College of Konkuk University at Hwayang-Dong, Kwangjin-Gu, Seoul from Aug. 1992 to foul. 1999. The results are as follows: The major component of yellow sand is soil particles based upon the observation that particles ranging from $3.3~7.0{\mu}m$ occupy 36~63%. It is certain that the increase of fine particles of respirable dust during yellow sand phenomenon in Seoul area affects the human body. The trace metals from natural sources like Al, Ca, Fe, K, Na, and Si show larger mass median diameter(MMD) values during yellow sand phenomenon than in normal situations while the values of MMD for Mn and Pb rarely changes. Noticeably, the changes in value of MMD of water soluble elements like ${NO_3}^{-}$ and ${SO_4}^{2}$ are 2.3 and 6.6 times higher during the yellow sand phenomenon compared to normal situations, respectively. This fact is regarded as decisive evidence showing that ${NO_3}^{-}$ and ${SO_4}^{2}$ in the air are attached to yellow sand and move together.

A Numerical Study on the Performance Characteristics of a Power Plant Air-Cooled Condenser (ACC) Affected by Changes in Operating Conditions (발전소용 공랭식 응축기(ACC)의 작동조건 변화에 따른 성능특성에 대한 수치적 연구)

  • Park, Kyung-Min;Ju, Kihong;Park, Chang Yong
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.26 no.2
    • /
    • pp.243-250
    • /
    • 2017
  • A numerical study was conducted to calculate the cooling capacity variation of a power plant ACC (air-cooled condenser) caused by changes in operating conditions. A numerical model was developed using the ${\varepsilon}-NTU$ and finite volume method, containing 100 elements for a single low fin tube. The model was validated through a comparison of cooling capacity between the simulated values and manufacturer's data. Even though simple assumptions and previously presented heat transfer correlations were applied to the model, the prediction error was 1.9%. The simulated variables of the operating conditions were air velocity, air temperature, and mass flux. The analysis on the variation of thermal resistance along the tube showed that the water side thermal resistance was higher than the air side thermal resistance at the downstream end of the tube, indicating that the ACC capacity could be increased by applying technology to enhance in-tube flow condensation heat transfer.

Changes in Carotenoid Pigments of Oleoresin Red Pepper during Cooking (고추 Oleoresin 의 가열조리중 Carotenoid 색소의 변화)

  • 최옥수;하봉석
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.23 no.2
    • /
    • pp.225-231
    • /
    • 1994
  • As the way of mass process of red pepper, extraction of oleoresin, which is labile during distribtuion and long-term storage, is alternative way to minimize markdown of red pepper quality. Changes of carotenoid pigments in modified oleoresin during cooking at high temperature were investigated. Dried red peperwas milled to 100 mesh of size particle and oily compounds were extracted by reduced pressure steam distillation. The rest part was reetracted and concentrated. The extracts were combined . The same volume of water and 4 % of polyglycerol condensed ricinoleate (PGDR) were added to the combined extract, and emulsified to make oleroesin. Capsanthin among dried red pepper, was the most abundant carotenoid (97.80mg%) followed by $\beta$ -cartoene, cryptoxanghin ,violaxanthin, crypotocapsin, and capsorubin. Oleoresin is acquiesce in the same order of raw red pepper. Transmittal of color components from raw red pepper to oleroresin was over 85% in cryptoxanthin, crytocapsin, and $\beta$ -carotene, over 70% in capsolutein and hydroxycapsolutein, and under 50% in antheraxanthin and mutatoxanthi Crytocapsin cryptoxanthin, an capsorubin in oleoresin red pepper were remained 72.1, 51.8 and 25.25, respectively, after cooking for 5hours at10$0^{\circ}C$. Color compounds were unsteady by cooking , About 90% of color compounds were destroyed by 3 hours cooking at 15$0^{\circ}C$. But, they were more thermostable under nitrogen circumstance than air one.

  • PDF

Spaceborne Gravity Sensors for Continental Hydrology and Geodynamic Studies

  • Shum C. K.;Han Shin-Chan;Braun Alexander
    • Korean Journal of Remote Sensing
    • /
    • v.21 no.1
    • /
    • pp.51-57
    • /
    • 2005
  • The currently operating NASA/GFZ Gravity Recovery and Climate Experiment (GRACE) mission is designed to measure small mass changes over a large spatial scale, including the mapping of continental water storage changes and other geophysical signals in the form of monthly temporal gravity field. The European Space Agency's Gravity field and steady state Ocean Circulation Explorer (GOCE) space gravity gradiometer (SGG) mission is anticipated to determine the mean Earth gravity field with an unprecedented geoid accuracy of several cm (rms) with wavelength of 130km or longer. In this paper, we present a summary of present GRACE studies for the recovery of hydrological signals in the Amazon basin using alternative processing and filtering techniques, and local inversion to enhance the temporal and spatial resolutions by two-folds or better. Simulation studies for the potential GRACE detection of slow deformations due to Nazca-South America plate convergence and glacial isostatic adjustment (GIA) signals show that these signals are at present difficult to detect without long-term data averaging and further improvement of GRACE measurement accuracy.

A Study of Changes in Body Shape, Temperament, Symptoms and Sasang Constitutional Values Using the Korea Sasang Constitutional Diagnostic Questionnaire (KS-15) : 5 Year Follow Up (사상체질 진단설문지(KS-15)를 이용한 외형, 성정, 병증의 추적관찰 및 체질값 변화 연구 : 5년 추적)

  • Kyoungsik Jeong;Bok-Nam Seo;Yunyoung Kim;Eunsu Jang
    • Journal of Sasang Constitutional Medicine
    • /
    • v.36 no.2
    • /
    • pp.1-11
    • /
    • 2024
  • Objectives The purpose of this study was to compare between baseline and follow up data after 5 years about the change of Sasang constitutional value. Methods Cohort data of educational personnel in D University was used. Korean Sasang Constitutional Diagnostic Questionnaire was used to compare Sasang value including body shape, temperament, and pathological symptoms in baseline with those of follow up. Paired t test, chi-square test, correlation analysis and cohen's kappa coefficient was used. Results Total 150 subjects participated in this analysis. Taeeumin, Soeumin and Soyangin was 71, 46 and 33 respectively. Height decreased in follow-up, and weight increased, accordingly body mass index increased(p<.05). The score of nocturia was significantly increased, and the temperature of drinking water was significantly decreased. The consistency rate of the Sasang constitutional values in KS-15 between baseline and follow up was 76%, and the kappa value was 0.607. Compared to the expert's diagnosis, the agreement rate was 66.7% in baseline and 69.3% in follow up. Conclusion As times goes by, Sasang Constitutional phenotype, such as body mass index, nocturia, and temperature of drinking water, and accordingly, the predicted value of Sasang constitution may be changed. Those who use Sasang constitutional type and therapy in clinics should consider these factors.

Simulation of Circulation and Water Qualities on a Partly Opened Estuarine Lake Through Sluice Gate (배수갑문을 통해 부분 개방된 하구호에서의 순환과 수질모의)

  • 서승원;김정훈;유시흥
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.14 no.2
    • /
    • pp.136-150
    • /
    • 2002
  • To improve the water quality of the recently constructed Siwhaho, sluice gates were operated to allow free exchange of water with the sea. This estuarine lake connected to the outer sea through narrow gates is affected mainly by flushing by gate operation and river flows and wind forcing sometimes. As a predicting tool far the water qualities, a three-dimensional finite volume model CE-QUAL-ICM is incorporated into a finite element hydrodynamic model, TIDE3D. In coupling these two different modules, a new error minimization technique is applied by considering conservation of mass. Model tests for one year after calibration and validation using field observation show that eutrophication and other biological changes reach quasi-steady state after initial 60 days of simulation, thus it would be necessary to consider moderate ramp up option to remove initial uncertainties due to cold start option. Sediment-water interaction might not be a concern in the long-term simulation, since its effect is negligible. Simulated results show the newly applied scheme can be applied with satisfaction not only fur lessening of eutrophic processes in an estuarine lake but also looking for some active circulation to improve water quality.

Numerical Simulation for Net-water Flux of the Cross-sectional area in the Nakdong River Estuary (낙동강 하구역내 사주간의 단면유량플럭스 수치모의)

  • Yoon, Han-Sam;Lee, In-Cheol;Ryu, Cheong-Ro
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.8 no.4
    • /
    • pp.186-192
    • /
    • 2005
  • We investigated the deposition characteristics and mass transport flux estimation of the Nakdong estuary, Korea. To understand the effects of the tidal current circulation that influences estuary terrain changes, we used a 2D numerical model to map seawater circulation under three different situations, with the level of river flow being set as none or flood. The net-water flux of the cross-sectional area between sandbars (known as dung) was estimated. From our review of previous research, we know that the development of local sandbars shifted from the west to the east side of the estuary after the construction of the Nakdong River dike. Current development is occurring mostly at the Bakhap-dung near Tadea. The seawater circulation pattern over this large-scale area of tidal na is brings changes related to the quantity of the outflow from the Nakdong River. Based on the calculated results for the net-water flux of the cross-sectional area, we see very strong accumulation in local waters around Jangjiado, Bakhapdung, and Tadae under flood river flow conditions, but accumulation in local waters around Jinudo under the other states of flow. Consequently, in the Nakdong estuary, the main sensitive regions that are affected by changes in the flow of river discharge are the local waters around Jangiado, Bakhapdung, Tadae, and Jinudo.

  • PDF

Synthesis of Schiff-Base Ligands and Determination of Stability Constants of Their Transition Metal(II) Complexes (질소-산소계 시프염기 리간드의 합성과 전이금속(II) 착물의 안정도상수결정)

  • Kim, Seon Deok;Song, Chan Ik;Kim, Jun Gwang;Kim, Jeong Seong
    • Journal of Environmental Science International
    • /
    • v.13 no.9
    • /
    • pp.835-843
    • /
    • 2004
  • N,N-bis(2-salicylaldehyde)dipropylenetriamine(5- Hsaldipn), N,N-bis( 5-bromosalicyl-aldehyde) dipropylenetriamine (5-Brsaldipn), N,N-bis(5-chlorosalicy laldehyde )dipropylene-triamine(5-Clsaldipn), N,N-bis(2-hydroxy- $5-methoxy-benzaldehyde)dipropylenetriamine(5-OCH_3saldipn)$ and N,N-bis (2-hydroxy-5-nitrobenzaldehyde)dipropylenetriamine $(5-NO_2saldipn)$ were synthesized and characterized by elemental analysis, infrared spectrometry, NMR spectrometry and mass spectrometry. Their proton dissociation constants were determined in 70% dioxane/30% water solution by potentiometric. Stability constants of the complexes between these ligands and the metal ions such as Cu(II), Ni(II) and Zn(II) were measured in dimethyl sulfoxide by a polarographic method. Stability constants for the ligands were in the order of $5-OCH_3$ > 5-H > 5-Br > 5-Cl > $5-NO_2$ saldipn. Enthalpy and entropy changes were obtained in negative values.

The impact of climate change on the European Alps : Artificial snow and environmental problems (긴급제언 - 유럽알프스지역의 기후변화 영향 : 인공설(雪)과 환경문제)

  • Lee, Yeong-Heui
    • Journal of the Korean Professional Engineers Association
    • /
    • v.45 no.2
    • /
    • pp.28-32
    • /
    • 2012
  • The European Alps face a number of major threats - from habitat loss to pollution, from mass tourism to the impacts of climate change. The European alpine climate has changed significantly during the past century, with temperatures increasing more than twice the global average. This makes alpine mountains especially vulnerable to changes in the hydrological cycle and decreases in snow and glacier cover, which are already occurring. In winter, artificial snow-making is currently the most widespread strategy to extend and supplement natural snow cover and secure winter tourism. Artificial snow-making is not only very costly, but also has knock-on effects such as increased water consumption and energy demand or ecological damage, which may lead to negative externalities. The European Alps facing the challenge of changing climate and anthropogenic pressures.

  • PDF

Beyond the clinical walls: registered dietitian nutritionists providing medical nutrition therapy in the home setting

  • Hicks-Roof, Kristen;Xu, Jing;Fults, Amanda K.;Latortue, Krista Yoder
    • Nutrition Research and Practice
    • /
    • v.15 no.6
    • /
    • pp.789-797
    • /
    • 2021
  • BACKGROUD/OBJECTIVES: Registered dietitian nutritionists (RDN) are providers of medical nutrition therapy (MNT) to address health and chronic disease. Traditionally, RDNs have provided care in healthcare facilities including hospitals and private care facilities. The purpose of this study was to determine how RDN individualized MNT in the home impacted nutrition, physical activity, and food security. SUBJECTS/METHODS: This is a secondary data analysis. The mean age of the participants (n = 1,007) was 51.6 years old with a mean body mass index (BMI) of 34.1 kg/m2. Individualized MNT visits were delivered by an RDN in the home setting from January to December 2019. Participants were referred by healthcare professionals or self-referred. Participants had MNT benefits covered by their health insurance plan (43.3% Medicaid; 39.8% private insurance; 7.9% Medicare, 9% other). Health outcomes related to nutrition care were measured. Outcomes included self-reported consumption of nutrition factors and physical activity. Our secondary outcome focused on food security. The changes in weight, BMI, physical activity, and nutrition factors were analyzed by a linear regression model or linear mixed model, adjusting for age, sex, baseline value, and number of appointments. Food security was summarized in a 2 by 2 contingency table. RESULTS: Baseline values had significantly negative impacts for all changes and number of appointments was significant in the changes for weight and BMI. Increases in physical activity were significant for both female and male participants, 10.4 and 12.6 minutes per day, respectively, while the changes in weight and BMI were not. Regarding dietary factors, the consumption total servings per day of vegetables (0.13) and water (3.35) significantly increased, while the consumption of total servings of whole grain (-0.27), fruit (-0.32), dairy (-0.80) and fish (-0.81) significantly decreased. About 24% (of overall population) and 45% (of Medicaid population) reported improvements in food security. CONCLUSIONS: This study found that home visits were a useful setting for MNT delivered by RDNs. There is a strong need for individualized counseling to meet the participants' needs and personal goals.