• Title/Summary/Keyword: carbon dioxide method

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Studies on the Preservation of Apples by Plastic Film Coating (Plastic Coating에 의(依)한 사과의 저장연구(貯藏硏究))

  • Park, Nou-Poung
    • Applied Biological Chemistry
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    • v.13 no.2
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    • pp.131-151
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    • 1970
  • A new method of plastic film coating has been investigated to extend storage life of apples. The film coating was effected by dipping fresh apples in a plastic emulsion. The effect of plastic film coating on the preservation of freshness, respiratory activities and chemical components during storage, has been investigated on four leading varieties of apples. The results are summarized as follows: 1. The effect of film coating on storage life of apples was apparent, resulting in delay of after-ripening, shriveling, softening or physiological impediment as well as reducing consumption of reserve materials and waste fruits. 2. Change in the partial pressure of gas, i.e., increase in carbon dioxide and decrease in oxygen in apple tissue was resulted by the plastic film coating, suggesting that the film deposited on the fruit interfered with the diffusion of gases formed therein. 3. The effects of plastic film coating on the fruit storage varied with the type of plastic emulsions, coating temperature, varieties of apples and degree of fruit ripening. As regard to apple varieties, good results were obtained with PVA 217 for both American Summer Pearmain and Jonathan, and PVC 443 for McIntosh. 4. Reduction in the diminution rates of L-malic acid, ascorbic acid and soluble pectin etc. during storage of apples may account for the improved storage life of the fruits treated with plastic films.

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Study on liquid carbonation using the recycling water of ready-mixed concrete (레미콘회수수를 이용한 액상탄산화에 관한 연구)

  • Lim, Yun-Hui;Lee, Ju-Yeol;Choi, Chang-Sik;Hong, Bum-Ui;Park, Jin-Won;Lee, Dae-Young;Park, Byung-Hyun
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.4
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    • pp.770-778
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    • 2013
  • In this study, a liquid carbonation method was applied for producing precipitate calcium carbonate by liquid-liquid reaction. We recycled the recycling water of ready-mixed concrete, one of construction waste for use source of carbonate ion. A supernatant separated from the recycling water of ready-mixed concrete, as a result of ICP analysis of a cation, $Ca^{2+}$ was contained up to 1100 ppm. We used MEA as a $CO_2$ absorbent for the liquid carbonation. A precipitate $CaCO_3$ was produced at more than MEA 20 wt%. The precipitate $CaCO_3$ as a final product was separated and dried. The result of XRD was confirmed the generation of $CaCO_3$ to calcite structure.

Prediction of Pollutant Emission Distribution for Quantitative Risk Assessment (정량적 위험성평가를 위한 배출 오염물질 분포 예측)

  • Lee, Eui Ju
    • Journal of the Korean Society of Safety
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    • v.31 no.4
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    • pp.48-54
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    • 2016
  • The prediction of various emissions from coal combustion is an important subject of researchers and engineers because of environmental consideration. Therefore, the development of the models for predicting pollutants very fast has received much attention from international research community, especially in the field of safety assessment. In this work, response surface method was introduced as a design of experiment, and the database for RSM was set with the numerical simulation of a drop tube furnace (DTF) to predict the spatial distribution of pollutant concentrations as well as final ones. The distribution of carbon dioxide in DTF was assumed to have Boltzman function, and the resulted function with parameters of a high $R^2$ value facilitates predicting an accurate distribution of $CO_2$. However, CO distribution had a difference near peak concentration when Gaussian function was introduced to simulate the CO distribution. It might be mainly due to the anti-symmetry of the CO concentration in DTF, and hence Extreme function was used to permit the asymmetry. The application of Extreme function enhanced the regression accuracy of parameters and the prediction was in a fairly good agreement with the new experiments. These results promise the wide use of statistical models for the quantitative safety assessment.

Investigation on the Effectiveness of Aqueous Carbonated Lime in Producing an Alternative Cementitious Material

  • Jo, Byung-Wan;Chakraborty, Sumit;Choi, Ji Sun;Jo, Jun Ho
    • International Journal of Concrete Structures and Materials
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    • v.10 no.1
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    • pp.15-28
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    • 2016
  • With the aim to reduce the atmospheric $CO_2$, utilization of the carbonated lime produced from the aqueous carbonation reaction for the synthesis of a cementitious material would be a promising approach. The present investigation deals with the aqueous carbonation of slaked lime, followed by hydrothermal synthesis of a cementitious material utilizing the carbonated lime, silica fume, and hydrated alumina. In this study, the aqueous carbonation reaction was performed under four different conditions. The TGA, FESEM, and XRD analysis of the carbonated product obtained from the four different reaction conditions was performed to evaluate the efficacy of the reaction conditions used for the production of the carbonated lime. Additionally, the performance of the cementitious material was verified analyzing the physical characteristics, mechanical property and setting time. Based on the results, it is demonstrated that the material produced by the hydrothermal method possesses the cementing ability. Additionally, it is revealed that the mortar prepared using the alternative cementitious material yields $33.8{\pm}1.3MPa$ compressive strength. Finally, a plausible reaction scheme has been proposed to explain the overall performances of the aqueous carbonation as well as the hydrothermal synthesis of the cementitious material.

The Effect of Oxygen and Carbon Dioxide Concentration on Soot Formation in Nonpremixed Flames Using Time Resolved LII Technique

  • Oh, Kwang-Chul;Shin, Hyun-Dong
    • Journal of Mechanical Science and Technology
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    • v.19 no.11
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    • pp.2068-2076
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    • 2005
  • The influence of oxygen concentration and CO$_{2}$ as diluent in oxidizer side on soot characteristics was studied by Laser Induced Incandescence, Time Resolved LII and Transmission Electron Microscopy photography in non-premixed co flowing flames. Through the comparison of TEM photographs and the decay rate of LII signal, suitable two delay times of TIRE-LII method and signal sensitivity ($\Delta$S$_{TIRE-LII/) were determined. The effects of O$_{2}$ and CO$_{2}$ as diluent in oxidizer side on soot formation are investigated with these calibrated techniques. The O$_{2}$+CO$_{2}$, N$_{2}$, and [Ar+CO$_{2}$] mixture in co-flow were used to isolate CO2 effects systematically. The number concentration of primary particle and soot volume fraction abruptly decrease by the addition of CO$_{2}$ to the co-flow. This suppression is resulted from the short residence time in inception region because of the late nucleation and the decrease of surface growth distance by the low flame temperature due to the higher thermal capacity and the chemical change of CO$_{2}$ including thermal dissociation. As the oxygen concentration increases, the number concentration of soot particles at the inception region increases and thus this increase of nucleation enhances the growth of soot particle.

A literature review and study on effect of Balneotherapy (수치료(水治療) 중 온천요법의 한의학적 문헌고찰 및 효능에 대한 연구)

  • Kim, Dong-Gun;Heo, Seong-Kyu;Kim, Eu-Gene;Heo, Young-Jin;Kong, In-Pyo;Han, Seok-Hun;Cho, Young-Ho;Kong, Kyung-Hwan;Jeong, Su-Hyeon;Cha, Yoon-Yeop
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.20 no.2 s.33
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    • pp.132-141
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    • 2007
  • Objectives : The purpose of this study is to consider the definition, history, classification and clinical effect of balneotherapy. Methods : We researched oriental documents and recent sources of balneotherapy. Results and Conclusions : 1. Balneotherapy is medical cure method which uses physical chemistry effects of water. 2. Records of balneotherapy are seen in oriental documents such as Hwangjenaegyeong(黃帝內經), Sinnongbonchogyeong(神農本草經), Jaebyoungwonhuron(諸病源候論), Youmoonsachin(儒門事親), Bonchogangmok(本草綱目) and Donguibogam(東醫寶鑑) etc. 3. Spa can classify eleven types according to ingredient. The types were as following. Simple thermal spirng, Common salt spring, Sodium bicarbonated spring, Sulfate spring, Radioactive spring, Acid spring, Sulfur spring, Carbon dioxide spring, Iron spring, Alum spring & Sulfate-iron spring, Bicarbonatealkaline spring. 4. Physical, chemical and environmental effect of spa therapy have effectiveness on the chronic and we akness disease more than acute disease. And balneotherapy have more effectiveness on digestive disease, pulmonary disease, metabolic disease, circulatory disease, muscle skeletal disease and dermatologic disease than any other diseases.

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Respiratory Activity of Bacteria in Various Concentrations of Glucose (박테리아의 산소소비량에 관한 실험적 고찰)

  • Choi, Hyung-Ja
    • Journal of Preventive Medicine and Public Health
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    • v.10 no.1
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    • pp.134-137
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    • 1977
  • The most efficient method for reducing the organic content of dilute liquid waste is by aerobic-biological treatment. Basically, the organisms responsible for treatment possess the ability to decompose complex organic compounds and to use the energy so liberated for their bodily functions: reproduction, growth, locomotion and so on. That part of organic matter used to produce energy is converted to the essentially stable end products of carbon dioxide, water and ammonia, while the remainder is converted to new cells which can be settled and thus removed from the liquid before the waste is discharged to the receiving body water. Oxygen must be supplied continuously during the aerobic process. In the field of sewage treatment the Warburg respirometer is used mainly for the measurement of the oxygen uptake of samples. In this experiment the Warburg constant volume respirometer was used to determine the oxygen uptake by bacteria in the presence of various glucose concentrations. The rate of oxygen uptake by the bacteria was expressed as the respiratory quotient. The result indicated that the oxygen uptake was proportional to the glucose concentration. The expecting equation of the regression line was Y=7.7+0.12X where Y: respiratory quotient, ${\mu}l.\;O_2$ taken up/mg. dry wt. bacterium/hr. X: concentration of glucose, mg/l

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Performance improvement of countercurrent-flow membrane gas absorption in a hollow fiber gas-liquid membrane contactor

  • Ho, Chii-Dong;Sung, Yun-Jen;Chen, Wei-Ting;Tsai, Feng-Chi
    • Membrane and Water Treatment
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    • v.8 no.1
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    • pp.35-50
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    • 2017
  • The theoretical membrane gas absorption module treatments in a hollow fiber gas-liquid membrane contactor using Happel's free surface model were obtained under countercurrent-flow operations. The analytical solutions were obtained using the separated variable method with an orthogonal expansion technique extended in power series. The $CO_2$ concentration in the liquid absorbent, total absorption rate and absorption efficiency were calculated theoretically and experimentally with the liquid absorbent flow rate, gas feed flow rate and initial $CO_2$ concentration in the gas feed as parameters. The improvements in device performance under countercurrent-flow operations to increase the absorption efficiency in a carbon dioxide and nitrogen gas feed mixture using a pure water liquid absorbent were achieved and compared with those in the concurrent-flow operation. Both good qualitative and quantitative agreements were achieved between the experimental results and theoretical predictions for countercurrent flow in a hollow fiber gas-liquid membrane contactor with accuracy of $6.62{\times}10^{-2}{\leq}E{\leq}8.98{\times}10^{-2}$.

A Pilot Study of Skin Resurfacing Using the 2,790-nm Erbium:YSGG Laser System

  • Rhie, Jong Won;Shim, Jeong Su;Choi, Won Seok
    • Archives of Plastic Surgery
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    • v.42 no.1
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    • pp.52-58
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    • 2015
  • Background The erbium:yttrium scandium gallium garnet (Er:YSGG) laser differs from other laser techniques by having a faster and higher cure rate. Since the Er:YSGG laser causes an appropriate proportion of ablation and coagulation, it has advantages over the conventional carbon dioxide ($CO_2$) laser and the erbium-doped yttrium aluminum garnet (Er:YAG) laser, including heating tendencies and explosive vaporization. This research was conducted to explore the effects and safety of the Er:YSGG laser. Methods Twenty patients participated in the pilot study of a resurfacing system using a 2,790-nm Er:YSGG laser. All patients received facial treatment by the 2,790-nm Er:YSGG laser system (Cutera) twice with a 4-week interval. Wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture were measured. Results Study subjects included 15 women and five men. Re-epithelization occurred in all subjects 3 to 4 days after treatment, and wrinkle reduction, reduction in pigment inhomogeneity, and improvement in tone and texture within 6 months of treatment. Conclusions The 2,790-nm YSGG laser technique had fewer complications and was effective in the improvement of scars, pores, wrinkles, and skin tone and color with one or two treatments. We expect this method to be effective for people with acne scars, pore scars, deep wrinkles, and uneven skin texture and color.

Current Status of Tree Height Estimation from Airborne LiDAR Data

  • Hwang, Se-Ran;Lee, Im-Pyeong
    • Korean Journal of Remote Sensing
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    • v.27 no.3
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    • pp.389-401
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    • 2011
  • Most nations around the world have expressed significant concern in the climate change due to a rapid increase in green-house gases and thus reach an international agreement to control total amount of these gases for the mitigation of global warming. As the most important absorber of carbon dioxide, one of major green-house gases, forest resources should be more tightly managed with a means to measure their total amount, forest biomass, efficiently and accurately. Forest biomass has close relations with forest areas and tree height. Airborne LiDAR data helps extract biophysical properties on forest resources such as tree height more efficiently by providing detailed spatial information about the wide-range ground surface. Many researchers have thus developed various methods to estimate tree height using LiDAR data, which retain different performance and characteristics depending on forest environment and data characteristics. In this study, we attempted to investigate such various techniques to estimate tree height, elaborate their advantages and limitations, and suggest future research directions. We first examined the characteristics of LiDAR data applied to forest studies and then analyzed methods on filtering, a precedent procedure for tree height estimation. Regarding the methods for tree height estimation, we classified them into two categories: individual tree-based and regression-based method and described the representative methods under each category with a summary of their analysis results. Finally, we reviewed techniques regarding data fusion between LiDAR and other remote sensing data for future work.