• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.2
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• pp.9-19
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• 2003

Nitrogen oxide gases which were produced by spontaneous reaction of nitrocellulose(NC) in the single base propellant accelerate the decomposition of propellant, and result in the reduction of shelf life. The amount of nitrogen oxide was reduced by the addition of 0.3wt% $CaCO_3$ to conventional stabilizer(DPA) and down of the solvent leaching temperature from $64^{\circ}C$ to $56^{\circ}C$, which extended the shelf life of the single base propellant as much as twice compare with commercial propellant. The perforation diameter increase of propellant from 0.64mm to 0.77mm could compensate for the drop of burning rate which was caused the addition of $CaCO_3$.

• Animal Bioscience
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• v.36 no.7
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• pp.1044-1058
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• 2023

Objective: The objective of this study was to characterize physiochemical and nutrient profiles of feedstock and co-products from canola bio-oil processing that were impacted by source origin. The feedstocks and co-products (mash, pellet) were randomly collected from five different bio-oil processing plants with five different batches of samples in each bio-processing plant in Canada (CA) and China (CH). Methods: The detailed chemical composition, energy profile, total digestible nutrient (TDN), protein and carbohydrate subfractions, and their degradation and digestion (CNCPS6.5) were determined. Results: The results showed that TDN_1x was similar in meals between CA and CH. CH meals and feedstock had higher, truly digestible crude protein (tdCP) and neutral detergent fiber (tdNDF) than CA while CA had higher truly digestible non-fiber carbohydrate (tdNFC). The metabolizable energy (ME_3x), net energy (NE_Lp3x, NE_m3x, and NE_g3x) were similar in meals between CA and CH. No differences were observed in energy profile of seeds between CA and CH. The protein and carbohydrate subfractions of seeds within CH were similar. The results also showed that pelleting of meals affected protein sub-fractionation of CA meals, except rapidly degradable fractions (PB1), rumen degradable (RDPB1) and undegrdable PB1 (RUPB1), and intestinal digestible PB1 (DIGPB1). Canola meals were different in the soluble (PA2) and slowly degradable fractions (PB2) between CA and CH. The carbohydrate fractions of intermediately degradable fraction (CB2), slowly degradable fraction (CB3), and undegradable fraction (CC) were different among CH meals. CH presented higher soluble carbohydrate (CA4) and lower CB2, and CC than CA meals. Conclusion: The results indicated that although the seeds were similar within and between CA and CH, either oil-extraction process or meal pelleting seemed to have generated significantly different aspects in physiochemical and nutrient profiles in the meals. Nutritionists and producers need to regularly check nutritional value of meal mash and pellets for precision feeding.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.991-996
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• 2004

Plastics are widely used in industry, because they are light, easily manufactured, and have high specific strength. And many researches to increase the strengths and to reduce the price are being conducted at now. One of these researches is concerning to additives. Foaming techniques are used to endow insulation properties, to improve specific strength, or reduce the material cost. Due to their unique properties, foamed plastics are applied to refrigerator, pipe, and insulators. Micro-cellular foaming is the latest foaming technique that was invented at 1980 in MIT. It is known that many tiny small cells are generated in the polymer matrices and micro-cellular foamed plastics show relatively high specific strength. We investigated the role of CaCO3 which is one of the most widely used additives in plastics industry as an additive for nucleation in view of cell morphology. CaCO3 used in this paper was treated to increase the dispersibility and to lower the density, so it has many pores at his body. Two experiments were conducted, in order to check the role of an additive for nucleation. One is compound-ability and the other one is role of nucleation agents.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.125-134
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• 2010

This study was performed to evaluate the workability, strengths and durability of polymer concrete using oyster shell that are reclaimed at public shore illegally or leaved on the surroundings of shore to prevent the environmental pollution. We investigated the effect of oyster shell powder (OSP) and $CaCO_3$. on the slump, compressive strength, flexural strength, acid sulfuric and freezing and thawing resistance as a filler of polymer concrete. Modified OSP obtained by crushing oyster shell (less than 0.15 mm size) consists of 60.47 wt% of $SiO_2$ and 39.5 wt% of $CaCO_3$. As a result of slump test by OSP and $CaCO_3$. contents, it is found that slump of specimen used OSP is lower than that used $CaCO_3$. and the more OSP contents are, its slump is increased. Compressive and flexural strength of polymer concrete using OSP are similar or slightly lower than that using $CaCO_3$. In acid sulfuric test for 5 % $H_2SO_4$ and freezing thawing test, regardless of kinds of fillers and contents are not found fatal defects in weight change, falling-off in surface and durability factor.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.4
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• pp.8-15
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• 2012

Optical property improvements for ONP (old newspaper) and OMG (old magazine) were attempted by application of in-situ $CaCO_3$ formation process on recycled fiber surfaces. Washing treatment of ONP and OMG resulted in 35~40% yield loss for around 6% brightness improvement. Washing plus bleaching process with $H_2O_2$ and FAS (formamidine sulfinic acid) improved brightness and ERIC values a little more with the same amount of yield loss as washing treatment. In-situ $CaCO_3$ formation method improved those optical properties much better than the washing plus bleaching method without loss of yield, and better than the case of adding high brightness PCC up to the same ash level. It can be said that the in-situ $CaCO_3$ formation method may be used as an effective alternative for upgrading optical properties of recycled fibers.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.6
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• pp.44-54
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• 2013

Replacing OMG (old magazine) to ONP (old newspaper) by raising optical property through $CaCO_3$ in-situ precipitation method in white duplex board presents cost reduction and possible drying energy saving. The strength property impairment by the presence of $CaCO_3$ could be supplemented by the fiber furnish treatment or strength polymer addition. In $CaCO_3$ in-situ precipitation of ONP, it was found from morphological study using FlowCAM, an image analyzer, that most of calcium carbonate were formed on the fines, and made the size of the fines larger. For the case of forming calcium carbonate only on the fractionated fines, the size of the fines were the biggest, and there were more clean surface areas available for bonding for the fractionated long fibers when fractionated fibers and fines were regrouped to make paper.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.54-60
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• 2023

In this study, microstructure and basic property analysis of DG (Desulfurization gypsum) and CCMs (Carbondioxide conversion capture materials) made by reacting CO₂ with DG were conducted to analyze applicability as a cement admixture. The main crystalline phases of DG were CaO and CaSO₄, and CCMs were CaSO₄, CaCO₃, Ca(OH)₂ and CaSO₄·H₂O. As a result of particle size analysis, the difference in average particle sizes between the two materials was about 7 ㎛. No major heavy metals were detected in the CCMs, and as a result o f TGA, the CO₂ decomposition of CCMs was more than twice as high as that of DG. Therefore, it was judged that CCMs could be used as a cement admixture through optimization of manufacturing conditions. As a results of measuring the strength behavior of DG and CCMs mixture ratios, the long-term strength of CCMs-mixed mortar was higher, and this is due to the filler effect of CaCO₃ in CCMs.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.245-245
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• 2007

• Korean Journal of Materials Research
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• v.13 no.4
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• pp.246-250
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• 2003

Calcium phosphate was prepared by chemical reaction formula using Oyster shells and $H_3$$PO_4$solutions. After added to 0.1 M∼0.9$ M H_3$$PO_4$ solution for oyster shell, prepared powders were investigated for heating properties and formation phase with heat treatment temperatures. As the results of XRD analysis of heated powders at $500^{\circ}C$∼$1200^{\circ}C$,$ CaCO_3$ phases were observed at the temperature of below 900 TEX>$^{\circ}C$ and in the condition of 0.1 M∼0.9 M $H_3$$PO_4$ solutions. However, $CaCO_3$, $CaPO_3$(OH) and $Ca_3$($PO_4$)$_2$ phases were appeared at the temperature range between $500∼900^{\circ}C$ and in the solution of 0.7 M to 0.9 M $H_3$$PO_4$. $Ca_{ 5}$($PO_4$)$_3$(OH) and CaO phases due to the decarbonation of oyster shells($CaCO_3$) were appeared at above $1000^{\circ}C$ and in the solution of below 0.5 M $H_3$X$PO_4$. However in the case of above 0.7 M $H_3$$H_4$ solutions, $Ca_{5}$ ($PO_4$)$_3$(OH) was decomposed into $Ca_3$($PO_4$)$_2$ at more higher 100$0^{\circ}C$. Thus $Ca_3$(X$Ca_4$)$_2$ phases were appeared at higher than 100$0^{\circ}C$.

• Food Science and Preservation
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• v.8 no.3
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• pp.239-245
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• 2001

The CA(Controlled Atmosphere) storage of cherry tomatoes were carried out under seven gas compositions including air. The weight loss of cherry tomatoes progressively increased with storage time. In the case of cherry tomatoes stored under CA conditions, increment of weight loss was reduced. However, cherry tomatoes (in air) tut about 15% weight at the end of storage. In CA stored cherry tomatoes lost about 10% weight at the same time. General trend was a decrease in titratable acidity with storage time. In air md 6.4% O$_2$, 4.2% CO$_2$, titratable acidity was lower than that in other storage conditions. During storage of cherry tomatoes, soluble solids increased till 8 days of storage, and then decreased. Stored cherry tomatoes in air and 6.4% O$_2$+4.2% CO$_2$ have lower values. Lycopene contents of cherry tomatoes with 6% O$_2$ storage condition increased and cherry tomatoes with 1% O$_2$+6% CO$_2$ and 3% O$_2$+3.1% CO$_2$maintained s initial contents. In air, flesh firmness decrease till 8 days, and then increase. At 1% O$_2$+6% CO$_2$ ethanol contents were ten times to that of other experimental conditions. Air and 6% O$_2$+7.8% CO$_2$ condition had lowest value for the ethanol content. In changes of organic acid and citric acid decreased slowly during storage, malic acid in air and below 3% O$_2$was disappeared at 8 days. Above 4% O$_2$concentration malic acid contents were maintained till 16 days. In over all acceptability, air and 6.4% O$_2$+7.8% CO$_2$ condition took a good score from the panel. Quality of stored cherry tomatoes was not edible condition in 1% O$_2$+6% CO$_2$. CA storage cherry tomatoes took a good score in firmness and juiciness where as control received good score in color and sweetness. This result was explained that in air ad 6.4% O$_2$+7.8% CO$_2$stored cherry tomato was ripened and full color development, but in CA was break stage because of suppressed ripening.