• Polymer(Korea)
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• v.25 no.6
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• pp.833-839
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• 2001

The crystallization characteristics of metallocene linear low density polyethylene was investigated by small angle light scattering and comparison was made with Ziegler-Natta linear low density polyethylene. The special efforts were made to find out the effects of branching number, length of branching and co-monomer content of m-LLDPE on the crystallization behavior of m-LLDPE. It was found that m-LLDPE has longer induction time to start crystallization from the amorphous state than that of conventional LLDPE with similar branching number, but the rate of crystallization seems not change much in both LLDPEs. Lowering of branching number in m-LLDPE resulted in both increasing of rate of crystallization and reducing induction time to crystallize. In general, the maximum size of spherulites of m-LLDPE is bigger than that of conventional LLDPE.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.379-384
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• 1994

A series of blends containing ethylene-vinyl alcohol(EVOH) and styrene-maleic anhydride(SMA) copolymers has been produced to study the effect of compatibilization on the crystallization behavior of the dispersed semicrystalline component. The crystallization behavior and the morphology of the blends have been characterized by differential scanning calorimetry(DSC) and scanning electron microscopy(SEM), respectively. Depending on the compatibilization, a part of crystallization of the dispersed phase took place with greater undercooking. Homogeneous crystallization was responsible for the shift of crystallization temperature for those compatibilized blends.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.3
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• pp.271-275
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• 2016

Recently, pollution problem in coastal water has become more serious and pollution including red tide serves as a main reason for reduction of fishes resources. Particularly, nutrients such as nitrogen and phosphorus are the most serious pollutants. Normally, biological wastewater treatment process is used in removing such nutrients. However, it is difficult to adopt the biological wastewater treatment process to a small-scale fish processing factory in case of using seawater as wash water. Thus, removing nutrients through struvite crystallization is investigated in this study for treating shrimp processing wastewater. Experiments were conducted by varying molar ratio of $Mg^{2+}:NH^4-N:PO^4-P$ from 1:1:1 to 2:1:1. It can be concluded that optimum molar ratio is 1:1:1. Struvite crystallization process is compared with chemical coagulation process using PAC and struvite crystallization process is proven as the more effective process in removing nutrients from wastewater. In view of results obtained from these experiments, struvite crystallization process is a promising method in removing nitrogen and phosphorus from wastewater; however, not so good in removing organics. Thus, struvite crystallization process is suitable as the pre-treatment process in treating shrimp processing wastewater and additional biological process is needed to remove organics.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.297-301
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• 2014

We examined the effect of ionic liquid on the crystallization efficiency of vancomycin in an increased surface area crystallization with silica gel. The crystallization efficiency was improved by the addition of ionic liquid, [BMIm][$BF_4$]. The addition of ionic liquid (20%, v/v) on the increased surface area crystallization with silica gel dramatically reduced the crystallization time by 6 folds (4 h), compared with the results of the case where the surface area-increasing material and ionic liquid had not been added. In addition, the crystal size of vancomycin was decreased and the crystal quality of vancomycin was improved by increasing the addition of ionic liquid.

• Archives of Pharmacal Research
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• v.7 no.2
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• pp.145-151
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• 1984

A novel agglomeration technique, termed "Spherical Crystallization Process", which can transform directly the fine crystals produced in the crystallization or the reaction process into a spherical shape was developed. By this technique, needle like crystals such as salicylic acid were transformed into free flowing and directly compressible agglomerates. Sphericaly agglomerated aminophyline crystals were obtained directly from the reaction system, which could reduce the preparation processes, e. g. synthesis, crystallization and agglomeration, into only one step. Sodium theophyline monohydrate agglomerates were prepared by salting out, the rate process of which was described by a first order kinetics. Agglomerated crystals of ndw complex of indo-methacin-mepirizole were prepare with this technique; an improved therapeutic effect of the resultant crystals was expected. expected.

• Journal of the Korean Ceramic Society
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• v.24 no.4
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• pp.364-368
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• 1987

The Si5AION7 specimens containing 20% YAG composition have been sintered and then heat treated to induce the crystallization of the matrix glassy phase. Crystallization of YAG phase during the heat treatment was detected from the X-ray diffraction patterns and the consequent changes in room temperature toughness as well as in microstructures were investigated. Almost all the glassy boundary phase were found to crystallize even after 5 minutes of heat treatment and the KC at room temperature decreased accordingly. The results show that the matrix crystallization can be induced by slow cooling from the sintering temperature.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.5-6
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• 2003

Kinetic study on the colloidal crystallization of single component and mixture of different sizes or densities of spheres was made in the exhaustively deionized suspensions and in microgravity, and compared with the results in normal gravity. Colloidal crystallization rates were retarded in microgravity for single component of spheres, whereas rates of alloy crystallization were enhanced substantially in microgravity. The rotational diffusion coefficients of colloids and the formation reaction rates of colloidal silica spheres were also studied in microgravity.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.177-180
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• 2002

Microwave has been utilized for low-temperature crystallization of amorphous Si films. Microwave annealing lowered the crystallization temperature and shortened the annealing time. The combination of Ni and microwave applications on a-Si films further enhanced the crystallization. The enhancement was due to both reduced nucleation activation energy and growth activation energy.

• Journal of Information Display
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• v.10 no.2
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• pp.76-79
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• 2009

In Joule-heating-induced crystallization, solid-to-solid or liquid-to-solid phase transformation could occur. It was found that novel physical phenomena that randomly nucleated liquid seeds, followed by rapid solidification in an amorphous matrix, during the Joule-heating-up period play an important role especially in liquid-to-solid transformation. Under some processing conditions, super-grains sized 6-8 ${\um}m$ were produced by the lateral growth from the initial seeds, without any artificially control.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.740-746
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• 2009

In the present study, the drowning-out crystallization of L(+)-calcium lactate was investigated in order to develop the crystallization separation process. The crystallization of the calcium lactate was induced by injecting the alcoholic anti-solvent into the aqueous solution of calcium lactate and the control of the calcium lactate crystal size during the crystallization was primarily investigated under the consideration of the anti-solvent species, anti-solvent composition and agitation speed as the key operating factors. Alcohols of methanol, ethanol, n-propanol and i-propanol were used as the anti-solvent for the drowning-out crystallization. Prior to the crystallization experiment, the solubility of calcium lactate in the water-alcohol mixture was measured along with the variation of the alcohol species and composition, which was necessary to estimate the supersaturation level of the crystallization. By the drowning-out crystallization, the calcium lactate crystals of the fabric shape were obtained. Using the ethanol as the antisolvent, the fabric crystals close to the needle shape were produced. However, the hairy crystals were obtained by using the propanol as the anti-solvent. Due to such morphological features, the crystals was highly apt to form the aggregates. The aggregation of the crystals was intensified as increasing the alcohol fraction in the water-alcohol mixture. Meanwhile, the agitation caused the breakage of crystals, resulting in the decrease of the crystal size. Therefore, the crystal size in the crystallization was predominantly determined by the competition between the crystal aggregation and breakage.