• Title/Summary/Keyword: dry water

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Studies on Food Preservation by Controlling Water Activity 1. Measurement of Sorption Isotherm of Dried Filefish Muscle by Equilibration in Dynamic Stream of Conditioned Air (식품보장과 수분활성에 관한 연구 1. 조절기류에 의한 건조말쥐치육의 등온흡습곡선의 측정)

  • HAN Bong-Ho;CHOI Soo-Il
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.14 no.4
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    • pp.189-193
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    • 1981
  • An apparatus for continuous measurements of sorption isotherm of dried food was manufactured to shorten the time required for equilibration. The apparatus was so designed that the temperature, air velocity and relative humidity in the experimental chamber could be controlled. The use of dynamic stream of conditioned air with a velocity of 0.2m/sec, instead of static atmosphere, allowed a faster equilibration of dried filefish muscle at $25^{\circ}C$. The mean time necessary for the equilibration of dried filefish muscle at the water activity of a given state to a higher water activity was about 45 hours. The monolayer moisture content of dried filefish muscle calculated from BET-equation was 0.092 kg water /kg dry matter at $25^{\circ}C$.

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Three dimensional deformation of dry-stored complete denture base at room temperature

  • Lim, Seo-Ryeon;Lee, Joon-Seok
    • The Journal of Advanced Prosthodontics
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    • v.8 no.4
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    • pp.296-303
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    • 2016
  • PURPOSE. The aim of this study was to evaluate whether there is any typical deformation pattern existing in complete denture when it was dried by using the 3D scanner and surface matching program. MATERIALS AND METHODS. A total of 28 denture bases were fabricated with heat curing acrylic resin (each 14 upper and lower denture bases), and 14 denture bases (each 7 upper and lower denture bases) were stored in the water bottle (water stored), and another 14 denture bases were stored in the air (dry stored). Each specimen was scanned at $1^{st}$ day after deflasking, $14^{th}$ day after deflasking, and $28^{th}$ day after deflasking, and digitalized. Three dimensional deformation patterns were acquired by comparison of the data within storage group using surface matching program. For evaluating differences between groups, these data were compared statisticallyusing Kruskal Wallis and Mann Whitney-U test (${\alpha}$=.05). RESULTS. When evaluating 3D deformation of denture base, obvious deformations were not found in maxillary and mandibular water storage group. However, in dry stored group, typical deformation pattern was detected as storage time passes. It occurred mostly in first two weeks. Major deformations were found in the bilateral posterior area in both maxillary and mandibular group. In maxillary dry stored group, a statistical significance was found. CONCLUSION. It was proved that in both upper and lower denture bases, dry storage caused more dimensional deformation than water storage with typical pattern.

Experimental study on the generation of ultrafine-sized dry fog and removal of particulate matter (초미세 크기의 마른 안개 생성과 이를 이용한 미세먼지 제거 연구)

  • Kiwoong Kim
    • Journal of the Korean Society of Visualization
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    • v.22 no.1
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    • pp.34-39
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    • 2024
  • With the fine particulate matter (PM) poses a serious threat to public health and the environment. The ultrafine PM in particular can cause serious problems. This study investigates the effectiveness of a submicron dry fog system in removing fine PM. Two methods are used to create fine dust particles: burning incense and utilizing an aerosol generator. Results indicate that the dry fog system effectively removes fine dust particles, with a removal efficiency of up to 81.9% for PM10 and 61.9% for PM2.5 after 30 minutes of operation. The dry fog, characterized by a mean size of approximately 1.5 ㎛, exhibits superior performance in comparison to traditional water spraying methods, attributed to reduced water consumption and increased contact probability between water droplets and dust particles. Furthermore, experiments with uniform-sized particles which sizes are 1 ㎛ and 2 ㎛ demonstrate the system's capability in removing ultrafine PM. The proposed submicron dry fog system shows promise for mitigating fine dust pollution in various industrial settings, offering advantages such as energy consumption and enhanced safety for workers and equipment.

Production Ecology of the Seagrass Zostera marina in Jindong Bay, Korea

  • Lee, Kun-Seop;Park, Jung-Im;Chung, Ik-Kyo;Kang, Dong-Woo;Huh, Sung-Hoi
    • ALGAE
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    • v.19 no.1
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    • pp.39-47
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    • 2004
  • Production dynamics of eelgrass, Zostera marina was examined in Jindong Bay on the south of the Korea peninsula. Eelgrass leaf productivities and environmental factors such as underwater photon flux density, water temperature, and nutrient availabilities in the water column and sediments were monitored from March 2002 to December 2003. While water temperature exhibited a distinct seasonal trend, underwater irradiance and nutrient availabilities exhibited high degree of fluctuation, and did not show a seasonal trend throughout the experimental periods. Eelgrass leaf elongation and production rates showed significant seasonal variations. Leaf productivity was highest in May (30.0 mg dry wt sht$^{-1}$ d$^{-1}$ or 3.7g dry wt m$^{-2}$d$^{-1}$) and lowest in November (3.2 mg dry wt sht$^{-1}$ d$^{-1}$ or 0.12 g dry wt m $^{-2}$ d$^{-1}$). Eelgrass leaf productivities did not show a strong correlation with underwater irradiance or environmental nutrient availabilities. The production rates, however, were positively correlated with water temperature during spring periods, and were correlated negatively at high water temperature exceeded 20℃ during summer months. While relative growth rates were highest in spring and lowest in high water temperature periods, plastochrone interval was longest during summer and shortest during spring. These results imply that seasonal growth dynamics of eelgrass, Z. marina was mainly controlled by water temperature.

Application of Dry/Wet Algorithm for 2-Dimensional Flow Analysis (2차원 흐름해석을 위한 마름/젖음 알고리듬의 적용)

  • Han, Kun-Yeun;Kim, Sang-Ho;Choi, Seung-Yong;Lee, Su-Chang
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.629-633
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    • 2008
  • Frequently occurring flood and drought have increased the necessity of an effective water resources control and management of river flows. Therefore, the simulation of the flow distribution in natural rivers is very important to the solution of a wide variety of practical flow problems in water resources engineering. Usually in many flow problems, two-dimensional approach can provide good estimates of complex flow features in the flow around islands and obstructions, flow at confluence and flow in braided channel. The objective of this study is to examine validation of developed an accurate and robust two-dimensional finite element method with wet and dry simulation in complex natural rivers. Milyang river, and Kumho river and Keum river were performed for tests. The results were compared with those of existing model. The suggested model displayed reasonable flow distribution compared with existing model in dry area for application of natural river flow. As a result of this study, the developed general two-dimensional model provide a reliable results for flow distribution of wet and dry domain, it could be further developed to basis for extending to water quality and sediment transport analysis.

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창원시 대산면 취수 부지의 지하수와 낙동강의 수리화학적 특성 비교

  • Ham Se-Yeong;Jeong Jae-Yeol;Lee Jeong-Hwan;Kim Hyeong-Su;Ryu Sang-Hun;Kim Tae-Won;Kim Mun-Su
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2006.04a
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    • pp.307-311
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    • 2006
  • Chemical analyses were conducted for Nakdong River water and riverbank filtrate in Daesan-Myeon area, Changwon City in 2005. Chemical components show different trends in wet season (June, July, August and September) and dry season (the other months). The patterns of chemical variation are classified into four types. Chemical components belonging Type I, as Na and $HCO_3$, show decrease in concentration during wet season and increase in concentration during dry season for both Nakdong River water and the riverbank filtrate. Chemical components belonging Type II, as Mg and $SO_4$, show decrease in concentration during wet season and increase in concentration during dry season for Nakdong River water while show the opposite trend for the riverbank filtrate. Chemical components belonging Type III, as Cl and $NO_3$, show increase in concentration from the start of wet season and high concentration during dry season for both Nakdong River water and the riverbank filtrate. Chemical components belonging Type IV, as Fe, show increase in concentration during wet season and decrease in concentration during dry season for both Nakdong River water and the riverbank filtrate.

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Species diversity, some biological aspects of fishes and water quality of Terie River, Beshilo Basin, Ethiopia

  • Assefa Tessema Tecklie
    • Fisheries and Aquatic Sciences
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    • v.27 no.6
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    • pp.356-365
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    • 2024
  • The study was conducted in the Terie River between January and April 2022. The objectives of the study were to assess the fish species composition, determine the length-weight relationship and condition factor and assess the water quality of the river using international water quality guideline for aquatic life. Gillnets with different mesh sizes, 4, 6, 8 and 10 cm were used to collect fish specimens in both dry and wet seasons. Immediately after capture, the total length (TL) and total weight (TW) of each individual were measured in centimeters and grams, respectively, and their relationship was determined using the power function. The physicochemical water quality parameters were analyzed using standard procedures and wagtech portable water quality Kits and Secchi Disk apparatus. A total of 667 fish specimens were collected from the Terie River, 410 and 257 in dry and wet seasons respectively. A total of six fish species, Oreochromis niloticus, Labeobarbus intermedius, Labeobarbus nedgia, Labeobarbus beso, Clarias gariepinus, and Ramius loti were recorded. For length-weight relationship and condition factor analysis, more abundant fish species (O. niloticus and L. intermedius) which were found in both seasons were selected. The length and weight relationship of L. intermedius were TW = 0.0073TL3.04 in dry and TW = 0.0337TL2.59 in we season indicated isometric and negative allometric growth respectively. While O. niloticus showed negative allometric growth, TW = 0.096TL2.44 and TW = 0.0335 TL2.76 in dry and wet seasons, respectively. The mean Fulton condition factor (FCF) of L. intermidus were 0.85 ± 0.03 and 0.94 ± 0.25 in dry and wet seasons, respectively. The FCF of O. niloticus was 1.70 ± 0.13 and 1.73 ± 0.12 in dry and wet seasons respectively. Except for ammonia, the physicochemical water quality parameters were with the permissible limit for aquatic life and are suitable for fishes Terie River. The river has commercially important fish specimens that could be used for food security and livelihood improvement. However, there is very limited fishing activity in the river due to less awareness on the value of fishes. Therefore, sustainable fishery development should be done in the river.

A Development of the Grain Moisture Dry System Using Water-rate Compensator and PID Controller (함수율 보정기와 PID제어기를 이용한 곡물 수분 건조 시스템 개발)

  • Lee, Chang-Kuen;Shim, Woo-Chul;Park, Sung-Jin;Hong, Yeon-Chan
    • Proceedings of the KIEE Conference
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    • 2001.11c
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    • pp.315-318
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    • 2001
  • In this paper recommends the development of automated silo dry & storage system. Most of existing round shaped iron silo arc used for only storage after dry and have many problems in storing. So We have developed an automated dry system which used the previously equipped silo and enables it to be used for storage after dry. The system features high frequency-resistance water sensor in Hopper scale that is in general use within the country its silo that is manufactured by the nerve DSP(TMS320C32) system water compensator and visualization that is finally realized with a personal computer.

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A Study on Stress-Strain Characteristics of Compacted Bentonite for High-Level Radioactive Waste Repository (고준위폐기물 차폐용 압축벤토나이트의 응력-변형률 거동 분석)

  • Kim, Do-Hyun;Jeong, Sang-Seom
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.792-797
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    • 2009
  • The stress-strain characteristics of compacted bentonite are investigated using experimental triaxial compression test by Hoek-cell. Special attention given to various dry density and water absorption ratio. Based on the test results, it is shown that the stress-strain relationship of compacted bentonite is highly influenced by dry density and water absorption ratio. Also, characteristics of Bentonite is similar to the clay rather than sand. Strength of compressed Bentonite increases with higher dry density. It shows maximum strength value, if in a same condition with dry density and constrain pressure. So we determine that value as the optimistic moisture contents for the maximun strength of compressed Bentonite.

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Numerical modeling of seawater flow through the flooding system of dry ocks

  • Najafi-Jilani, A.;Naghavi, A.
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.1 no.2
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    • pp.57-63
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    • 2009
  • Numerical simulations have been carried out on the flooding system of a dry located at the south coasts of Iran. The main goals of seawater flow haracteristics in the intake channels conditions of the flooding system are imposed in the modeling. The upstream boundary condition is the tidal fluctuations of sea water level. At the downstream, the gradually rising water surface elevation in the dry described in a transient boundary condition. The numerical results are compared with available laboratory a good agreement is obtained. The seawater discharge through the flooding system and the required time to filling up the dry dock is determined at the worst case. The water current velocity and pressure on the rigid boundaries are discussed.