• 제목/요약/키워드: Deposition risk

검색결과 73건 처리시간 0.03초

Preliminary analyses on decontamination factors during pool scrubbing with bubble size distributions obtained from EPRI experiments

  • Lee, Yoonhee;Cho, Yong Jin;Ryu, Inchul
    • Nuclear Engineering and Technology
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    • 제53권2호
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    • pp.509-521
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    • 2021
  • In this paper, from a review of the size distribution of the bubbles during pool scrubbing obtained from experiments by EPRI, we apply the bubble size distributions to analyses on the decontamination factors of pool scrubbing via I-COSTA (In-Containment Source Term Analysis). We perform sensitivity studies of the bubble size on the various mechanisms of deposition of aerosol particles in pool scrubbing. We also perform sensitivity studies on the size distributions of the bubbles depending on the diameters at the nozzle exit, the molecular weights of non-condensable gases in the carrier gases, and the steam fractions of the carrier gases. We then perform analyses of LACE-ESPANA experiments and compare the numerical ~ results to those from SPARC-90 and experimental results in order to show the effect of the bubble size distributions.

Analysis of Erosion Risk in a Catchment using Projected Rainfall Data and Spatial Rainfall-Erosion Model

  • Felix, Micah Lourdes;Kim, Joocheol;Choi, Mikyoung;Jang, Ning;Jung, Kwansue
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2021년도 학술발표회
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    • pp.316-316
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    • 2021
  • Erosion in a watershed is one of the main sources of sediment inflow in dams. While sediment management practices can be performed to reduce and manage sedimentation in reservoirs, managing the sediment inflow before it reaches the reservoir should also be consider. The accurate location of areas with high erosion and deposition rates should be determined in order to propose an appropriate sediment management procedure such as the construction of check dams. In this study, the projected rainfall from HadGEMRA-3 for RCP 8.5, was used in C-SEM, a distributed rainfall-erosion model, to determine the projected spatial erosion patterns in Cheoncheon catchment, which is located in the upstream part of Yongdam Dam.

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수면과 알츠하이머 치매의 관계 (Relationship Between Sleep and Alzheimer's Dementia)

  • 이경환;김호찬
    • 수면정신생리
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    • 제29권1호
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    • pp.1-3
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    • 2022
  • Sleep is associated with Alzheimer's dementia. Many previous researches have shown that inadequate sleep is one of the risk factors that predict Alzheimer's dementia. The causal mechanism of this association is not clear. Slow wave sleep and REM sleep are critical stages in memory consolidation, and by sequential hypothesis both stages are important. Deposition of amyloid beta and tau, the main pathology of Alzheimer's dementia, are also associated with sleep. This review provides the association of sleep and Alzheimer's dementia, and future research is necessary to examine the specific mechanism of this association between sleep and Alzheimer's dementia, which may lead to an early intervention in sleep.

Image Evaluation and Association Analysis of the Cardiovascular Disease of the Degree of Pancreatic Steatosis in Ultrasonography

  • Cho, Jin-Young;Ye, Soo-Young;Ko, Seong-Jin
    • Transactions on Electrical and Electronic Materials
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    • 제17권6호
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    • pp.375-379
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    • 2016
  • Increasing fat tissue of obese people, increases the rate of cardiovascular disease, diabetes, metabolic syndromes and dyslipidemia. An increase in the focal tissue of pancreas is a known risk factor of these diseases. Although there exists sufficient research on the diagnosis and treatment of pancreatic cancer, studies have been done on fatty pancreas. In this study, based on ultrasound imaging and using a texture characteristic of GLCM, fatty pancreas was divided into three categories: mild, moderate and severe. We compared and analyzed the three groups was by Pancreatic ultrasonography and body characteristics, serological tests, pressure and the degree of arteriosclerosis, against normal control group. The following parameters of control and test groups were measured: WC (waist circumference),BMI (body mass index), TC (total cholesterol), TG (triglyceride), HDL-C (High-density lipoprotein cholesterol) and LDL-C (Low-density lipoprotein cholesterol), SBP (systolic blood pressure), BST (Blood Sugar Test) and aortic PWV (pulse wave velocity). We observed the values correspondingly increasing fat deposition. However, ABI (Ankle Brachial pressure index) stenosis and HDL-C levels decreased with increasing fat deposit (p <0.05); a drop in these parameters are known to be harmful to the human body. The difference in texture characteristics between normal control group and pancreatic fatty group (mild, moderate, and severe) was statistically confirmed. Ultrasound imaging of pancreatic steatosis categorized the disease as mild, moderate and severe based on the characteristic texture. In conclusion, we observed on increase in metabolic syndrome, dyslipidemia, and arteriosclerosis, proportional to the degree of pancreatic fat deposition. The escalation of these diseases was confirmed and was directly related with predictors of cardiovascular diseases.

홍수터에서의 홍수위험도 예측을 위한 홍수터 안정성 평가 지수 개발 (A study on the development of flood plain stability evaluation Index for flood risk assessment in floodplain)

  • 구영훈;송창근;박용성;김영도
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2016년도 학술발표회
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    • pp.69-69
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    • 2016
  • 하천은 크게 하도와 홍수터 그리고 제방으로 나눌 수 있으며, 국내에서는 다른 국가들과 다르게 대하천사업 이후 하천의 홍수터에 생태공원이나 체육시설 등과 같은 다양한 친수시설들을 조성하여 활용하고 있다. 하지만 최근 이상기후로 인해 홍수의 발생빈도 및 강도가 증가하고 있으며 여름철 집중호우에 의한 하천의 홍수위 상승은 이러한 친수시설의 침식과 퇴적 등과 같은 침수피해를 가중시키는 원인이 되기도 한다(Ku et al., 2013). 따라서 이와 같은 홍수피해를 예측하기 위해서는 홍수터를 포함한 복단면에서의 수치해석이 선행되어야 하며, 일반적으로 2차원 수치해석이 바람직한 것으로 제안되고 있다(Sato et al., 1989). 또한 하천에서의 2차원 수치해석 결과를 이용하여 침식과 퇴적에 관한 친수시설 안정성 평가 지수를 산정할 수 있으며, 산정된 지수를 통해 홍수터에서의 홍수피해를 예측할 수 있다. 다른 국가에서는 국내와 다르게 홍수터에 대한 활용이 거의 없기 때문에 홍수에 따른 홍수터에서의 위험도를 평가한 연구는 거의 없는 실정이며, 한국에서도 홍수터에서의 홍수위험도 평가에 대한 연구는 Song et al.(2016)이 다른 국가에서 활용하고 있는 제내지에서의 홍수위험도 평가 지수를 홍수터에 도입하여 실제 태풍에 의한 홍수위험도를 간접적으로 평가한 연구 정도가 대부분이라고 볼 수 있다. 따라서 본 연구에서는 Einstein-Krone 공식(1962)을 이용하여 침식과 퇴적을 동시에 고려할 수 있는 Transient Erosion and Deposition Index(TEDI)와 Steady Erosion and Deposition Index(SEDI)를 개발하였다. 또한 개발된 지수를 실제 자연하천에 적용하여 태풍 사상에서의 산정된 지수를 통해 홍수터 안정성을 평가하였다.

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Effect of Different Spray Dried Plasmas on Growth, Ileal Digestibility, Nutrient Deposition, Immunity and Health of Early-Weaned Pigs Challenged with E. coli K88

  • Bosi, P.;Han, In K.;Jung, H.J.;Heo, K.N.;Perini, S.;Castellazzi, A.M.;Casini, L.;Creston, D.;Gremokolini, C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권8호
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    • pp.1138-1143
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    • 2001
  • A total of 96 piglets were weaned at 19 and 13 days in Exp. 1 and 2, respectively, and allotted to one of four diets: three with different spray dried plasmas (SPs) and one with hydrolysed casein (HC). SPs were from pigs (SPP), mixed origin (SMP), and mixed origin with standardized level of immunoglobulins (SMPIG). All the diets contained 1.7% total lysine, 25% of the test protein source, 45% corn starch, 15% lactose, 2% sucrose, 7% soybean oil. At d 4 and d 2 in Exp. 1 and 2, respectively, piglets were perorally challenged with $10^{10}$ CFU E. coli K88. Growth performance, immunity, and health condition were measured for 15 days and 14 days in Exp. 1 and 2, respectively. To investigate apparent ileal digestibility and nutrient deposition, all piglets were sacrificed at d 14 in Exp. 2. In 1. 3 piglets died in HC diet and 1 in SPP diet. HC diet showed higher mortality (p<0.01) than other diets. In Exp. 2, no clinical sign of infection was detected, no difference for the content of E. coli K88 was found in feces at 4 and 6 days after the infection, and no E. coli K88 was found in the jejunum at the end of experiment. In both experiments, feed intake was lower for HC diet and ADG was 96, 106, 122 and 155 for HC, SPP, SMP and SMPIG diet, respectively (HC vs others, p<0.05; SMPIG vs other SP, p<0.01). Heal apparent digestibility of nitrogen in sacrificed piglets was higher for HC diet (p<0.05). After the challenge, K88-specific titers in saliva (Exp. 1) and in plasma (Exp. 2) were reduced in SMP and SMPIG. The piglets positive to the adhesion of the used E. coli strain to the intestinal brush borders had a significantly reduced growth (p<0.01) and a higher K88-specific IgA titer in plasma, in comparison with negative ones. This effect was independent of the diet. The data show the relevance of spray dried plasma sources and particularly of SP with standardized level of immunoglobulins for the feeding of early-weaned at the risk of infection by enterotoxigenic bacteria.

Polycyclic Aromatic Hydrocarbons (PAHs) and their Bioaccessibility in Meat: a Tool for Assessing Human Cancer Risk

  • Hamidi, Elliyana Nadia;Hajeb, Parvaneh;Selamat, Jinap;Razis, Ahmad Faizal Abdull
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권1호
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    • pp.15-23
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    • 2016
  • Polycyclic aromatic hydrocarbons (PAHs) are primarily formed as a result of thermal treatment of food, especially barbecuing or grilling. Contamination by PAHs is due to generation by direct pyrolysis of food nutrients and deposition from smoke produced through incomplete combustion of thermal agents. PAHs are ubiquitous compounds, well-known to be carcinogenic, which can reach the food in different ways. As an important human exposure pathway of contaminants, dietary intake of PAHs is of increasing concern for assessing cancer risk in the human body. In addition, the risks associated with consumption of barbecued meat may increase if consumers use cooking practices that enhance the concentrations of contaminants and their bioaccessibility. Since total PAHs always overestimate the actual amount that is available for absorption by the body, bioaccessibility of PAHs is to be preferred. Bioaccessibility of PAHs in food is the fraction of PAHs mobilized from food matrices during gastrointestinal digestion. An in vitro human digestion model was chosen for assessing the bioaccessibility of PAHs in food as it offers a simple, rapid, low cost alternative to human and animal studies; providing insights which may not be achievable in in vivo studies. Thus, this review aimed not only to provide an overview of general aspects of PAHs such as the formation, carcinogenicity, sources, occurrence, and factors affecting PAH concentrations, but also to enhance understanding of bioaccessibility assessment using an in vitro digestion model.

Development of a nanoparticle multi-generator for assessment of inhalation hazard

  • Lee, Sung-Bae;Han, Jeong-Hee;Kim, Tae-Hyun;Cha, Hyo-Geun;Lim, Cheal-Hong
    • 분석과학
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    • 제34권2호
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    • pp.87-98
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    • 2021
  • In this study, we developed the nanoparticle multi-generator by 3D printer fusion deposition modeling (FDM) method that can reliably generate and deliver nanoparticles at a constant concentration for inhalation risk assessment. A white ABS filament was used as the test material, and SMPS was used for concentration analysis such as particle size and particle distribution. In the case of particle size, the particle size was divided by 100 nm or less and 100 to 1,000 nm, and the number of particles concentration, mass concentration, median diameter of particles, geometric average particle diameter, etc were measured. The occurrence conditions were the extruder temperature, the extruding speed of the nozzle, and the air flow rate, and experiments were conducted according to the change of conditions including the manufacturer's standard conditions. In addition, the utility of inhalation risk assessment was reviewed through a stability maintenance experiment for 6 h. As a result of the experiment, the size of the nanoparticles increased as the discharger temperature increased, as the discharge speed of the nozzle increased, and as the air flow rate decreased. Also, a constant pattern was shown according to the conditions. Even when particles were generated for a long time (6 h), the concentration was kept constant without significant deviation. The distribution of the particles was approximately 80 % for particles of 60 nm to 260 nm, 1.7 % for 1 ㎛ or larger, 0.908 mg/㎥ for the mass concentration, 111 nm for MMAD and 2.10 for GSD. Most of the ABS particles were circular with a size of less than 10 nm, and these circular particles were aggregated to form a cluster of grape with a size of several tens to several hundred nm.

Effects of monochromatic lights on the growth performance, carcass characteristics, eyeball development, oxidation resistance, and cecal bacteria of Pekin ducks

  • Hua, Dengke;Xue, Fuguang;Xin, Hairui;Zhao, Yiguang;Wang, Yue;Xiong, Benhai
    • Animal Bioscience
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    • 제34권5호
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    • pp.931-940
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    • 2021
  • Objective: Light is a significant component of housing environment in commercial poultry industry. This study was conducted to investigate whether Pekin ducks perform better under monochromatic lights than under white light with respect to their growth performance, carcass quality, eyeball development, oxidation resistance, and cecal bacterial communities. Methods: A total of 320 one-day-old male Pekin ducklings were randomly distributed into five rooms with different light treatments, white, red, yellow, green, and blue light. Each room consisted of 4 replicated pens with 16 ducklings per pen. Results: Blue light significantly decreased fat deposition by decreasing abdominal fat. Long wavelength light, such as red, green, and yellow light, considerably increased the back-to-front eyeball diameter and the red light potentially enlarged the side-to-side eyeball diameter. Besides, the blue light had adverse effects on the oxidation resistance status in terms of increasing the product malonaldehyde of lipid oxidation and decreasing the plasma concentration of total superoxide dismutase. The phyla of Firmicutes had the greatest abundance in the green and blue treatments, while Bacteroidetes in blue treatment was the least. The genus of Faecalibacterium was significantly lower under the red light. Conclusion: The high risk of cecal health status and decreased anti-oxidation activity were observed under blue light. Red, yellow, and green light might increase the risk of oversized eyeball and cecal illness. Therefore, monochromatic lights compared to white light did not show advantages on the performance of housing ducks, it turns out that the white light is the best light condition for grow-out ducks.

Hole Selective Contacts: A Brief Overview

  • Sanyal, Simpy;Dutta, Subhajit;Ju, Minkyu;Mallem, Kumar;Panchanan, Swagata;Cho, Eun-chel;Cho, Young Hyun;Yi, Junsin
    • Current Photovoltaic Research
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    • 제7권1호
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    • pp.9-14
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    • 2019
  • Carrier selective solar cell structure has allured curiosity of photovoltaic researchers due to the use of wide band gap transition metal oxide (TMO). Distinctive p/n-type character, broad range of work functions (2 to 7 eV) and risk free fabrication of TMO has evolved new concept of heterojunction intrinsic thin layer (HIT) solar cell employing carrier selective layers such as $MoO_x$, $WO_x$, $V_2O_5$ and $TiO_2$ replacing the doped a-Si layers on either front side or back side. The p/n-doped hydrogenated amorphous silicon (a-Si:H) layers are deposited by Plasma-Enhanced Chemical Vapor Deposition (PECVD), which includes the flammable and toxic boron/phosphorous gas precursors. Due to this, carrier selective TMO is gaining popularity as analternative risk-free material in place of conventional a-Si:H. In this work hole selective materials such as $MoO_x$, $WO_x$ and $V_2O_5$has been investigated. Recently $MoO_x$, $WO_x$ & $V_2O_5$ hetero-structures showed conversion efficiency of 22.5%, 12.6% & 15.7% respectively at temperature below $200^{\circ}C$. In this work a concise review on few important aspects of the hole selective material solar cell such as historical developments, device structure, fabrication, factors effecting cell performance and dependency on temperature has been reported.