• Journal of the Korean Ceramic Society
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• v.53 no.3
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• pp.332-337
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• 2016

As a case study on yttria stabilized zirconia ceramics, the sintering characteristics of submicron powders and the granulation prepared by two-fluid spray drying of submicron particles were investigated. As-received powders of yttria stabilized zirconia particles were reduced to a uniform size of less than about 200 nm by repeated milling. Granulation size obtained by the two-fluid spray drying was affected by the organic matter and the primary particle size. Sintering behavior such as porosity, water absorption ratio, density, and transparency was influenced by processing conditions of the powder, and the discontinuous interfaces in a green body were reduced.

• The Korean Journal of Ceramics
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• v.1 no.1
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• pp.35-39
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• 1995

Yttrium aluminum garnet(YAG) powders were synthesized by spray-drying of the hydroxides coprecipitated from a mixture of aqueous solutions of $Al(NO_3)_3.9H_2O \;and\; Y(NO_3)_3.6H_2O$ Phase formation in the powders during heat treatments and their sintering charactristics were investigated. In the powder obtained by washing the hydroxides before spray-drying, a metastable yttrium aluminum hexagonal (YAH) phase was first crystallized and then transformed into YAG as temperature was increased. The formation of YAH was attributed to a deviation in compositions of the particles from the starting composition of YAG. However, the powder prepared without washing step contained a stable yttrium aluminum monoclinic(YAM) phase in addition to YAG due to a large deviation from the starting composition. A powder compact of a single phase YAG was pressureless-sintered for 4 hrs at $1700^{\circ}C$ and the density was 93% of the theoretical density.

• Food Science of Animal Resources
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• v.21 no.3
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• pp.265-271
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• 2001

We investigated changes of immunoglobulin G (IgG) concentrations by heating and drying condition. Also it is performed to group for commercial product by promoting of IgG preservation and reducing of protein denaturation. The result was that content of IgG in colostrum was higher than normal milk. Especially, IgG content of colostrum within 12 hrs after parturition was over 44.67mg/ml and it is 60 times of normal milk. IgG contents was reduced rapidly according as passage of the time. IgG content of the sample heating at 30min at 65$^{\circ}C$ was still a little higher that heating for 10sec at 72$^{\circ}C$. IgG denaturation of heat treatment at 100$^{\circ}C$ for 10sec was lower than at 85$^{\circ}C$ for 30min. We investigated the changes of IgG concentrations of kinds of market milk different with heating processing. This result showed that IgG denaturation ratio by ultra high temperature pasteurization (UHT) was higher than long time low temperature pasteurization (LTLT). On the other hands, IgG content by spray drying was 14.5mg/g and freezing drying was 10.8mg/g. It showed that denaturation of protein content by freezing drying was more than spray drying.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1323-1328
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• 2004

This paper shows the study on the design of the spray-freeze dryer for the production of the pulmonary inhalation powders. Powder production and handling has been an integral part of pharmaceutical processing because of the wide use of oral dosage forms. There are a few commonly used powder preparation methods including mechanical milling, precipitaion, spray drying, freeze drying, and so on. In general, methods available for preparing inhalation powders are limited due to certain inhalation powder's sensitive nature to the processing environments. This is particularly true for preparing dry powder aerosols where the aerodynamic particle size$(<5{\mu}m)$ and the size distribution are pivotal. Supercritical fluid antisolvent and spray freeze drying have recently emerged as promising techniques for producing powders for use in microcapsulation. However, the aerosol applications of these powders are yet to be explored. The purpose of this study is to test the feasibility of using spray freeze-dried pulmonary inhalation powders for aerosolization.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1178-1182
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• 2005

Survival of thermotolerant Lactobacillus reuteri KUB-AC5 in $20\%$ (w/v) skim milk was found to be $11.3\%$ after spray drying by using a pilot scale spray dryer with inlet temperature at $170^{\circ}C$ and outlet temperature at $85^{\circ}C$. The ability of dried cell to produce antimicrobial activity was not affected by the spray drying. The model system for predicting viability of spray-dried L. reuteri KUB-AC5 during long-term storage was established, based on the Arrhenius equation, and verified by experimental data, because the viability of cells during storage can be correlated with storage temperature. The viability during storage at $30^{\circ}C$ declined more rapidly than that storage at $4^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.32 no.9
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• pp.1047-1055
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• 1995

Mn-Zn ferrite granules were formed by a spray-drying method of the slurry containing different kinds and concentrations of binders at various temperatures. The slurry was made by conventional ceramic processing method, that is, by mixing Fe2O3, MnO, ZnO powders (52 : 24 : 24 mol%), calcining and milling. Typical shape of the spray dried granules was spherical. The compaction behavior of these granules was dependent on the spray-drying temperature and the kind and concentration of binders. At lower pressure the granules were displaced and at higher pressure the granules were deformed and fractured to fill pores among the granules. The optimum concentration of the binder was 0.5wt%. The granules containing 0.5wt% PVA 205 were deformed and fractured well and the green density was higher than others. At higher concentrations of the binder the granules were deformed rather than fractured, therefore the green density was lowered because of the remaining unfilled pores. The decomposition temperature and the heat released were increased with increasing the concentration of the binders. The compaction response of the granules containing PVA 205 was more efficient than those containing PVA 217 and PVA 117. Green density was not dependent on the degree of hydrolysis of the binders. The compaction response of the granules spray-dried at 15$0^{\circ}C$ was most efficient.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.1-6
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• 2004

This paper shows the study on the design and another applications of the spray-freeze dryer for the production of valuable material powders. Powder production and handling has been an integral part of material extracting processing and pharmaceutical processing because of the wide use of oral dosage forms. There are a few commonly used powder preparation methods including mechanical milling, precipitaion, spray drying, freeze drying, and so on. In general, methods available for preparing inhalation powders are limited due to certain inhalation powder's sensitive nature to the processing environments. This is particularly true for preparing dry powder aerosols where the aerodynamic particle size($<5{\mu}m$) and the size distribution are pivotal. Supercritical fluid antisolvent and spray freeze drying have recently emerged as promising techniques for producing powders for use in microcapsulation. However, the aerosol applications of these powders are yet to be explored. The purpose of this study is to test the feasibility of using spray freeze-dried valuable material powders for aerosolization.

• Journal of the Korean Ceramic Society
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• v.33 no.9
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• pp.1057-1063
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• 1996

Y2O3-CeO2-ZrO2 powders were prepared from water-soluble salts using a coprecipitation method. The forming process of oxide and the characteristics of the calcined powders treated in different drying conditions were investigated. The oxidation was occurred at the temperature of around 40$0^{\circ}C$ and the main crystallization of ZrO2 around $600^{\circ}C$. On calcination at $600^{\circ}C$ heating lamp-dried powders consisted of agglomerates of globular morphology with average agglomerate size of 2.27${\mu}{\textrm}{m}$ and specific surface area of 68.3m2/g and spray dried powders contained dense spheric particles with average agglomerate size of 1.35${\mu}{\textrm}{m}$ and specific surface area of 11.0m2/g which exhibited low agglomeration tendency. Removal of the water by a freeze-drying technique produced calcined powders containing flake-like secondary particle structures with wide agglomerate size distri-bution of 0.1-60${\mu}{\textrm}{m}$ and specific surface area of 24.5${\mu}{\textrm}{m}$. The 20 MPa-pressed density (36.8-41.4% T,D) of calcined powders did not nealy depend on drying methods whilst compaction ratio of calcined powders derived from freeze-drying was the highest ( 6.24) among three drying methods. On continuous heating up to 150$0^{\circ}C$ the sinterability of calcined powders derived from heating lamp-drying was superior to those derived from spray-and freeze-drying. The final sintered density of calcined powders was the highest (96% T,D at 150$0^{\circ}C$) in case of heating lamp-drying.

• Food Science and Preservation
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• v.9 no.2
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• pp.194-199
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• 2002

This study was conducted to develop processing method for vinegar powder from natural vinegar for encapsulation applications. To optimize the spray drying process, experiment was designed by central composition method to find optimal conditions for manufacturing vinegar powder. The acidity, water absorption, solid content and heat stability of vinegar powder were selected as response variables. The optimal concentration of inclusion complex which was made with vinegar and ${\beta}$-cyclodextrin was determined on 30。bx. On increasing the concentration of ${\beta}$-cyclodextrin as a wall material, the quality of the vinegar was decreased. The optimum conditions of spray drying process for manufacturing vinegar powder were 188∼192$^{\circ}C$ and 500∼600 Lh$\^$ -1/ as inlet temperature and flow rate, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.191-195
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• 2004

Drug delivery systems that are based on pectin have been studied for colon specific delivery using the specific activity of colon microflora. The aim of this study was to design a novel method of manufacturing pectin microspheres without oils and surfactants and to investigate the potential use of the pectin microspheres as an oral colon-specific drug carrier. The pectin microspheres were successfully formed using the spray drying method and crosslinking with calcium chloride. From the crosslinked pectin microspheres, indomethacin (IND) release was more suppressed than its release from non-crosslinked microspheres. In a low pH (pH 1.4) environment, the pectin microspheres released IND at an amount of about 18${\pm}$2% of the total loaded weight for 24 h while the release rate of IND was stimulated at neutral pH (pH 7.4). IND release from the pectin microspheres was increased by the addition of pectinase. The results clearly demonstrate that the pectin microspheres that were prepared by the spray drying and crosslinking methods are potential carriers for colon-specific drug deliveries.