• Title/Summary/Keyword: low humidity

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Development of curing facility to improve environment for burley curing (I. Changes in microclimate during air-curing) (버어리종 잎담배 건조 환경 개선을 위한 건조실 개발 (I. 건조기간중의 미기상 변화))

  • Cha, Kwang-Ho;Jang, Soo-Won;Yang, Jin-Chul;Oh, Kyoung-Hwan;Shin, Seung-Ku;Jo, Chun-Joon
    • Journal of the Korean Society of Tobacco Science
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    • v.29 no.2
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    • pp.66-73
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    • 2007
  • This study was carried out to investigate the changes of curing condition on microclimate of temperature, relative humidity during curing process of burley tobacco leaves. The developed facility, ridge opening type was designed to open the central top roof. The air-cured variety, (N. tabacum cv KB111) was normally grown at the Eumseong tobacco experimental station in 2007. Mean daily temperature of $3^{\circ}C$ in ridge opening type curing facility was lower than that of conventional, whereas mean daily relative humidity of 12.6 % RH was lower in conventional curing facility for the entire stage of curing. The frequency distribution of optimal air temperature at daytime was higher 37.5 % in ridge opening type curing facility than that of conventional, while that of optimal relative humidity was lower 8.2 %. In the ridge opening type curing facility, the excessive drying leaves were low, however the price per kilogram was high. These results suggest that the new developed curing facility may be applied to improved microclimate inside the curing facility for curing burley.

A Study on Drying Characteristics and Drying Model Development of Korean Ginseng (인삼의 건조특성 구명 및 건조모델 개발에 관한 연구)

  • Choe, Byeong-Min;Lee, Jong-Ho;Park, Seung-Je
    • Journal of Ginseng Research
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    • v.16 no.2
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    • pp.111-123
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    • 1992
  • Drying characteristic data for peeled ginseng were obtained to determine dominant drying factors and fitted with five selected drying models and an empirical model. Among air temperature, relative humidity and diameter of ginseng root, drying air temperature was found to be the most influencing factor on drying rate. Drying velocity appeared faster as the drying temperature increased but its effect was less at high temperature than at low temperature. Quality change during the drying process did not occur except when relative humidity was 75fb. At high relative humidity, skin color of ginseng was turned to light brown. Approximate-Diffusion and the Empirical model for drying were in a good agreement with experimental data. The models are as follows; $.$ Approximate-Diffusion model MR = A$.$exe(-k$.$1) A = 1.72 + 0.407 In(D) - 0.0000963T3 - 0.358 In(RH) + 0.0000945 RH2 B= 1.01 + 0.0195RH - 0.O0518D2 + 0.0708 In(T) - 0.492 In(RHI-D.0000933RH2$.$Empirical model MR= Cl + Cs$.$In(t) Cl= 1.14+0.382 In(D)-0.00008477a-0.139 In(RH)+0.0000664RH2 Cs=0.440-0.0224 In(D)-0.193 In(T)+0.0000464T2-0.00000771RH2

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Resistive Humidity Sensor from Copolymers Containing Quaternary Ammonium Salt (I): Three Component Copolymers (4차 암모늄염을 포함하는 공중합체를 이용한 저항형 습도센서(I) : 3원 공중합체)

  • Lee, Dong-Geun;Lim, Tae-Ho;Jeon, Young-Min;Gong, Myoung-Seon
    • Polymer(Korea)
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    • v.31 no.3
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    • pp.194-200
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    • 2007
  • The resistive-type polymeric humidity sensors were prepared from the copolymers of [2- [(methacryloyloxy)ethyl] dimethyl] propylammonium bromide(MEPAB), [2- [(methacryloyloxy)ethyl]-2-hydroxyethyl]dimethylmonium bromide (MEHDAB), n-butyl methylacrylate(MBA), 2-hydroxyethyl methylacrylate(HEMA) and styrene. Four kinds of copolymers, ie, MEPAB/styrene/MEHDAB MEHDAB/BMA/HEMA, MEPAB/BMA/MEHDAB, and MEPAB/styrene/HEMA crosslinked with blocked-isocyanate on the Ag/Pd electrode/alumina substrate showed good durability at high humidities. The various electrical properties such as frequency dependency, temperature dependency, hysteresis, response time and water durability were examined. In the case of copolymer MEPAB/BMA/MEHDAB= 3/6/1, the resistance was varied from $2.9 M{\Omega}$ to $1.84k{\Omega}$ at $25^{\circ}C$ in the range of $30{\sim}90%RH$ and this copolymers showed a good linearity and low hysteresis.

The effect of H2O, NH3 and applied voltage to the particle conversion in the desulfurization system using a nano-pulse plasma (나노펄스 플라즈마를 이용한 탈황 시스템의 H2O 및 NH3, 펄스 인가전압에 따른 입자변환 분석)

  • Kim, Younghun;Shin, Dongho;Lee, Gunhee;Hong, Keejung;Kim, Hak-Joon;Kim, Yong-Jin;Han, Bangwoo;Hwang, Jungho
    • Particle and aerosol research
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    • v.16 no.1
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    • pp.1-8
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    • 2020
  • Nano-pulse plasma technology has great potential as the process simplicity, high efficiency and low energy consumption for SO2 removal. The research on the gas-to-particle conversion is required to achieve higher efficiency of SO2 gas removal. Thus, we studied the effect of the relative humidity, NH3 concentration and applied voltage of the nano-pulse plasma system in the gas to particle conversion of SO2. The particles from the conversions were increased from 10 to 100 nm in diameter as relative humidity, NH3 concentration, applied voltage increases. With these results, nano-pulse plasma system can be used to more efficient removal of SO2 gas by controlling above parameters.

Fabrication of Block Copolymer Membranes via SNIPS Process (SNIPS 공정을 이용한 블록공중합체 분리막의 구조 형성에 관한 연구)

  • Woo, Sanghoon;Kim, Jinhee;Lee, Junghyun;Bang, Joona
    • Korean Chemical Engineering Research
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    • v.55 no.2
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    • pp.214-219
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    • 2017
  • In this work, we fabricated PS-b-P4VP block copolymer membranes from self-assembly and non-solvent induced phase separation (SNIPS), which combines the block copolymer self-assembly and conventional NIPS process. While previous studies mostly focused on the fabrication of well-defined structures, we systematically examined various processing parameters such as polymer concentration, solvent evaporation duration, solvent composition, and humidity, to optimized the membrane structures. As a result, the morphology of PS-b-P4VP membranes was optimized at a certain polymer concentration in solution and composition of volatile solvent at low humidity conditions, resulting in SNIPS separation membranes with well-defined nanopores on the surface, 75% of membrane porosity, and 18% of surface porosity.

Indoor radon and thoron from building materials: Analysis of humidity, air exchange rate, and dose assessment

  • Syuryavin, Ahmad Ciptadi;Park, Seongjin;Nirwono, Muttaqin Margo;Lee, Sang Hoon
    • Nuclear Engineering and Technology
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    • v.52 no.10
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    • pp.2370-2378
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    • 2020
  • Building materials contribute significantly to the indoor radon and thoron levels. Therefore, parameters that influence the exhalation rates of radon and thoron from building material need to be analyzed closely. As a preliminary study, the effects of humidity on exhalation rates were measured using a system with an accumulation chamber and RAD7 detector for Korean brick, Korean soil, and Indonesian brick. Resulting doses to a person who resides in a room constructed from the building materials were assessed by UNSCEAR method for different air exchange rates. The measurements have revealed that Korean brick exhaled the highest radon and thoron while Indonesian brick exhaled the lowest thoron. Results showed that for a typical low dense material, radon and thoron exhalation rate will increase until reached its maximum at a certain value of humidity and will remain saturated above it. Analysis on concentration and effective dose showed that radon is strongly affected by air exchange rate (ACH). This is showed by about 66 times decrease of radon dose from 0.00 h-1 to those of 0.50 h-1 ACH and decrease by a factor of 2 from 0.50 h-1 to those of 0.80 h-1. In case of thoron, the ACH doesn't have significant effects on effective dose.

Spatial Interpolation and Assimilation Methods for Satellite and Ground Meteorological Data in Vietnam

  • Do, Khac Phong;Nguyen, Ba Tung;Nguyen, Xuan Thanh;Bui, Quang Hung;Tran, Nguyen Le;Nguyen, Thi Nhat Thanh;Vuong, Van Quynh;Nguyen, Huy Lai;Le, Thanh Ha
    • Journal of Information Processing Systems
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    • v.11 no.4
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    • pp.556-572
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    • 2015
  • This paper presents the applications of spatial interpolation and assimilation methods for satellite and ground meteorological data, including temperature, relative humidity, and precipitation in regions of Vietnam. In this work, Universal Kriging is used for spatially interpolating ground data and its interpolated results are assimilated with corresponding satellite data to anticipate better gridded data. The input meteorological data was collected from 98 ground weather stations located all over Vietnam; whereas, the satellite data consists of the MODIS Atmospheric Profiles product (MOD07), the ASTER Global Digital Elevation Map (ASTER DEM), and the Tropical Rainfall Measuring Mission (TRMM) in six years. The outputs are gridded fields of temperature, relative humidity, and precipitation. The empirical results were evaluated by using the Root mean square error (RMSE) and the mean percent error (MPE), which illustrate that Universal Kriging interpolation obtains higher accuracy than other forms of Kriging; whereas, the assimilation for precipitation gradually reduces RMSE and significantly MPE. It also reveals that the accuracy of temperature and humidity when employing assimilation that is not significantly improved because of low MODIS retrieval due to cloud contamination.

Design of Smartfarm Environment Controller Using Fuzzy Control Method and Human Machine Interface for Livestock Building (퍼지 제어법과 HMI를 이용한 축사용 스마트팜 환경 제어기 설계)

  • Byeong-Ro Lee;Ju-Won Lee
    • Journal of the Institute of Convergence Signal Processing
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    • v.23 no.3
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    • pp.129-136
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    • 2022
  • The most important part of the smart livestock building system is to maintain a breeding environment so that livestock can grow to high quality despite changes in the internal and external atmospheric environment. Especially, it is very important to maintain the temperature and humidity in the livestock building because various diseases occur during the summer and winter. To manage the environment suitable for livestock, a smartfarm system for livestock building is applied, but it is very expensive. In this study, we propose a hardware design and control method for low cost system based on HMI and fuzzy control. To evaluate the performance of the proposed system, we did a simulation experiment in the atmospheric conditions of summer and winter. As a result, it showed the performance of minimizing the temperature and humidity stress of livestock. And when applied to the livestock building, the proposed system showed stable control performance even in the change of the external atmospheric environment. Therefore, as with these results, if proposed system in this study is applied to the smart farm system, it will be effective in managing the environment of livestock building.

Physiological responses and subjective sensation of human body wearing Cool Mapsi in air-conditioning environment (냉방환경에서 쿨맵시 착용에 따른 생리적 반응과 주관적 감각)

  • Kang, Noo-Ri;Na, Young-Joo
    • Science of Emotion and Sensibility
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    • v.13 no.2
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    • pp.359-370
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    • 2010
  • The purpose of this study is to test the performance of the recommended summer dressing for office man through the analysis of skin temperature changes by air-conditioning temperature. We tested two clothing combinations; formal wear with necktie and casual shirts without necktie as for Cool mapsi. 4 male subjects sat to stabilize for thirty minutes after entering artificial-climate chamber with both temperature of $25^{\circ}C$, $27^{\circ}C$ and $50{\pm}10%$ R.H. And during 60 minute experiments of simulating office work, the subjective feelings including thermal, humidity and comfort sensation, skin temperature, clothing humidity and sweat amount were measured at the equal intervals. The result is that formal wear of $25^{\circ}C$ and Cool mapsi of $27^{\circ}C$ show good values such as low skin temperature, low clothing humidity and neutral thermal sensation. And Cool mapsi of $25^{\circ}C$ shows the risk of low rectal temperature for long and static energy level of office work. Formal wear of $27^{\circ}C$ shows high values of mean skin temperature, clothing humidity and thermal sensation. Second experiment was to find the ambient temperature when the subject wearing formal wear shows the skin temperature corresponding to which he shows on Cool mapsi of $27^{\circ}C$. The air-conditioning temperature on wearing formal wear has to be $2^{\circ}C$ lower to produce the corresponding skin temperature to which shows on wearing Cool mapsi of $27^{\circ}C$. Therefore it is possible to increase room temperature to $27^{\circ}C$, when wear Cool mapsi for summer office, for skin temperature and thermal sensation are produced the same.

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Tolerance of Korean Cronobacter spp. (Enterobacter sakazakii) Isolates to Dessication (국내에서 분리한 Cronobacter spp.(Enterobacter sakazakii)의 건조내성 특성)

  • Lee, Eun-Jin;Ryu, Tae-Hwa;Park, Jong-Hyun
    • Korean Journal of Food Science and Technology
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    • v.41 no.6
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    • pp.681-686
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    • 2009
  • Cronobacter spp. (Enterobacter sakazakii) is known to be highly resistant to dry conditions than any other Enterobacteriaeae. In this study, one hundred and ten Korean Cronobacter isolates were characterized to find out their survival characteristics under conditions of desiccation and humidity. Thirty percentage strains of the isolates showed high resistance to desiccation exposed on the metal surface for eight hours by half survival of the initial number, whileas less than 10% strains showed dry sensitivity by less one log scale survival among seven log scales. Finally, more than 90% of the strains consisted of dry-resistant and dry-intermediate groups. The same tendencies were evident in a 15-day exposure. Dry-resistant and intermediate strain groups showed 3 log scale survival among 5 log initial numbers in the powdered infant formula for 30 days, which were more resistant than on the above metal surface exposed. So, almost the isolate strains showed high resistance to dry condition. Dry-resistant and intermediate groups exposed on the metal surface formed a biofilm at the beginning, and the dry-sensitive group showed biofilm formation mainly only after a 7-day exposure. However, without a time difference in formation of biofilm, the dry-resistant and sensitive isolates seemed to similar biofilm formation activity. Most of the isolates showed very low survival at 75% relative humidity in 48 hours; however, they showed high resistance by 60% survival at 40% relative humidity. The Cronobacter isolates showed high resistance to desiccation on the metal surface and in the powdered infant formula, but low survival at high relative humidity. Therefore, high humidity may be a control method for Cronobacter in food processing environments.