• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.564-569
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• 2005

Recently, from the viewpoint of global wanning, natural gas CO2 is considered as a main refrigerant for hot water system. The characteristics of CO2 is not toxic, not flammable, high pressure, and high refrigerating capacity. Also it is widely available as a byproduct of industrial processes. This paper describes the performance analysis program of the swash plate type compressor using CO2 refrigerant. Estimates of the refrigerant flow rate, compression work, discharge temperature and volumetric, compressor efficiencies of the CO2 swash plate type compressor are obtained from the various design parameter such as the inclination angle of the swash plate, discharge hole area and suction hole area.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.33-34
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• 2013

Recently, as the policy of state that it is the low carbon green growth is promoted, the effort for reducing the CO₂ gas generation ejected from the construction industry in the cement production is continued. That is, the method using the mineral admixtures including the silica fume and red mud, silica fume and etc. it is the industrial byproduct with the method solving the exhaustion problem of the environmental contamination settlement and natural resources, the great quantity as the cement substitute material is examined. Accordingly, in this research, the strength characteristic of the curing body differentiating the curing method of the ternary system inorganic binder using the blast furnace slag and red mud, silica fume and etc. as the cement substitute material tried to be examined.

• Journal of Powder Materials
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• v.27 no.4
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• pp.287-292
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• 2020

The subject of this study is a zeolite generated as a by-product of recycling LAS (lithium-aluminum-silicate) resources, a kind of glass and ceramic produced by induction. The zeolite by-product is modified into Mg-zeolite using Mg as a cation to absorb Pb, a heavy metal generated from water pollution caused by recent industrial wastewater. An ion-exchange method is used to carry out the modification process, from zeolite byproduct to Mg-zeolite, and simultaneously absorb the Pb in the heavy-metal solution (99.032 mg/L). It is found that the sodium zeolite in the raw material residue can be modified to magnesium zeolite by reacting it with a mixture solution at 1 M concentration for 24 h. As a result, it is found that the residual Pb (0.130 mg/L) in the heavy metal solution is shown to be absorbed by 99.86%, with successful formation of a Mg-modified zeolite.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.2
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• pp.130-137
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• 2018

In the construction industry, research on alkali activated cement using fly ash or blast furnace slag fine powder has been published in Korea and abroad as a way to reuse industrial byproducts without using cement at all and to obtain economical effects at the same time. the purpose of this paper is to evaluate the effect of the ratio and coefficient of hydration ratio and lime saturation degree on the strength of alkali activated slag cement by chemical quantitative analysis of alkali activated slag cement used in the management of existing portland cement. as a result, it was confirmed that the ratio and coefficient of hydration ratio and lime saturation are all within a certain range.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.272-279
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• 2004

The process for the preparation of fungicide propineb starting with 1,2-diaminopropane was studied on the optimal condition base. Side reaction producing toxic material 1,2-propylenethiourea could be ieduced effectively by using phase transfer catalyst and the product was noticed to show a great improvement in yield and purity. Especially when the phase transfer catalyst tetraphenylphosphonium bromide is used, the yield and the purity of the product were found to be best with up to 95 and 96% respectively and the byproduct content was shown within 1.7%. Also, the contents of wetting agent AES and dispersing agent APS were optimally chosen $3.1\sim4.0%$ and $4.0%\sim5.0%$ respectively for the improvement of suspensibility and wettability of Propineb WP.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.369-375
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• 2008

To achieve zero-emission, one of the main goals of an eco-industrial park (EIP), it is needed to develop an effective water exchange network. The network includes various subsystems and decision making processes, which make the modeling process extremely complicated. Agent-based modeling was used to simulate water exchange network in an EIP. Firm agents were created based on the behavior pattern of firms, and an agent-based model (ABM) was made with the agents, showing the growth of the exchange network. An existing steel and iron making industrial park was chosen as a case study, and the ABM model shows eco-efficient behavior with a decreased environmental cost. Water reuse network based on the ABM model results in 35% decrease of the fresh water supply and 50% reduction of the wastewater generation in EIP. A case study shows that agent-based model can be a powerful tool in modeling and designing complex eco-industrial parks, especially when a part of the system needs to be changed.

• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.78-85
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• 2007

This study provides an attempt to evaluate sanding wastes, generated from a chemical company as a reused adsorbent. Organic impurities in the raw sanding wastes were removed by calcination at $550^{\circ}C$. Aluminum was a major inorganic composition in the raw sanding wastes and increased from 29.09% to 52.73% after calcination. Dissolved concentrations of heavy metals from the calcined sample were below 0.3 mg/L in a stability test at pH 2. From the pH-edge adsorption experiments with the calcined sanding wastes, As (V) was found to follow an anionic-type adsorption. Adsorption isotherm obtained with variation of the dosage of the calcined sanding wastes was better described by Freundlich equation than Langmuir one. Freundlich constants of K and 1/n were 4.244 and 0.316, respectively. The As (V) adsorption capacity of calcined sanding wastes estimated from Langmuir isotherm was 13.25 mg/g. From this study, the calcined sample was identified as a good reusable adsorbent in the view point of stability and adsorption capacity on As (V).

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1593-1598
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• 2003

Nutritional evaluation of some agro-industrial byproducts available in Samoa [dry brewers' grains (DBG), cocoa shell (CS), cocoa dust (CD) and desiccated coconut waste meal (DCWM)] available in Samoa was carried out using both the in vivo and in vitro techniques. In the in vivo study 24 Anglo-nubian goats were offered by-products with other feed ingredients to compound four different diets. The goats were randomly allocated to 4 diets on the basis of liveweight (18.7-0.3kg). The ADF content of the byproducts followed a similar trend to NDF. The byproducts have a high content of organic matter (91.0-95.4%). Gross energy (GE) content was higher in DCWM (25.1 MJ/kg DM), closely followed by CD (23.2 MJ/kg DM). Concentrate intake was significantly different (p<0.05) among the goats. Average daily live weight gains were 105, 92, 88 and 97 g/goat/day for DBG, CS, CD and DCWM, respectively. Daily live weight gains were higher (p<0.05) in the goats that received DBG, while the least gain was obtained in the goats that received CS byproduct diet. DM digestibility was significantly higher (p<0.05) in the goats on DBG diet than in the other goats. The least DM digestibility was obtained in the goats that received CD diet (p>0.05). CP digestibility followed a similar pattern to DM digestibility. The digestibility of NDF and ADF was influenced by the nature of the diets. The digestibility of OM and GE were best (p<0.05) in the goats that received DBG, DCWM and CS byproduct diets than in CD. Significant differences (p<0.05) among the byproducts were recorded for net gas production. Potential gas production (a+b) ranged from 7.064 to 42.17 ml. Organic matter digested (OMD) from gas production value at 24 h was higher in DBG (47.6 g/kg DM) and this was followed by DCWM (42.5 g/kg DM). The least OMD was obtained in CD (17.9 g/kg DM). A significant difference (p<0.05) in DM disappearance after 4, 8, 16, 24, 48 and 72 h was recorded. The potential and effective degradability varied significantly (p<0.05) from 85.95-99.6 g/kg DM and from 39.9-65.8%, respectively. The digestibility of the byproducts in both the in vivo and in in vitro techniques demonstrated that they are potential source of feed ingredients for ruminant livestock in Samoa and possibly in the other small Pacific Island countries. On the basis of their potential degradability the byproducts could be ranked in the following order:DCWM>DBG>CD>CS. In conclusion, the results obtained suggest that all the byproducts can contribute to ruminant livestock diets without adverse effects on feed intake, growth rate and apparent nutrient digestibility coefficients.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.1
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• pp.89-96
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• 2023

In this paper, a ferrosilicon by-product was evaluated to confirm the feasibility of recycling it as supplementary cementitious material of ordinary Portland cement in concrete. Three different levels of replacement ratio (10 %, 20 % and 30 % of total binder) were applied to find which is the most beneficial to be used as a binder. Ferrosilicon concrete was initially assessed at setting time and compressive strength. Durability was evaluated by the resistance to chloride penetration test(RCPT) and alkali-silica reaction(ASR) with a comparison to silica fume concrete due to their similarity in chemical composition. The porosimetry and X-ray diffraction analysis along with energy dispersive X-ray spectroscopy give information on the microstructural characteristics of the ferrosilicon concrete. It was found that 10 % ferrosilicon concrete has higher strength while 20 %, 30 % have lower strength than OPC concrete. However, chemical resistance to chloride attack is higher when replacement is increased. Compared to silica fume, the durability of ferrosilicon might be less efficient however, it is obviously beneficial than OPC. High SiO₂ content in ferrosilicon results in producing more C-S-H gel which could make denser pore structure. Most of the risk of alkali silica reaction to silicate binders through length change tests was less than 0.2 %, and both mortar using ferrosilicon and silica fume showed better resistance to alkali silica reaction as the substitution rate increased.Reuse of industrial waste rather than producing highly refined additives might reduce environmental load during manufacture and save costs.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.116-126
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• 2015

The present study utilized a shuttle mechanism of wet chemical absorption using MEA. In addition, industrial by-products containing a large amount of inorganic alkali substances were utilized for wet carbonization process. Chemical pretreatment of industrial by-products extracted calcium ions. ICP result of calcium ion was obtained up to 17,900 ppm(17.9%) by acidic substance. And also, In this work, 94% of recovery rate was obtained using wet MEA absorption process from $CO_2$ flow at the ambient condition. Through the liquid carbonation process, a sludge was fixed with rate of 0.175 mg of $CO_2$ per mg of sludge. It was found from XRD results that the structure of final product was composed of a calcite structure which is general structure of $CaCO_3$.