• Korean Journal of Crystallography
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• v.3 no.1
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• pp.37-43
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• 1992

KTiOP04 is a nonlinear optical crystal which is most widely used for frequency doubling of the radiation of Nd : YAG laser. In the experiment, sin ale crystals of KTiOP04 were grown by TSSG technique using 3K2W04·P2O5 flux. Low temperature gradient furnace suitable for KTP single crystal growth was used. Seed crystal was placed at the surface of the solution for the purpose of better observation of the growing crystals and the possibility of diameter control. Solution included 66.7mol% KTiOP04 for all experiments and its saturation temperature was 1020℃. The conditions of single crystal growth were as follows: cooling rate 0.2℃/h, crystal rotation rate 50rpm, c -axis seed. Using these conditions, single crystals up to 23 ×25×25mm3 have been groan from about 100cc solution. We have also observed a change in the crystal growth habit which resulted in the formation of large (201) faces and small (100) faces. And some crystals have (101) faces.

• Journal of Photoscience
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• v.3 no.3
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• pp.159-161
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• 1996

Photosensitivity of silver halide emulsion depends on the properties of the microcrystals. Size, shape, grain distribution and chemical composition as well as the inner structure or the topography of the latent image specks affect on the optical properties and play an important role in the photographic process. In the present paper, a study on the sensitization of emulsion containing AgBrClI core/shell grains showed that for the given size, shape, halide content and crystal habit, under the optimal conditions the photosensitivity of the heterojunction type grains are different from that of the common regular grains. The optimal photosensitivity was obtained at the iodide content of 2.0 mo1%.

• Journal of Pharmaceutical Investigation
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• v.18 no.2
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• pp.55-59
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• 1988

The size of furosemide was reduced by the recrystallization method in order to increase the dissolution rate of the drug. Surfactants or hydrophilic polymers were used to suppress the aggregation in the crystal formation-growth process of microparticles by dispersing action. Dissolution rate of microparticles increased remarkably due to the size reduction of microparticle. The particle size decreased with increasing the concentration of the drug and the dispersing agents, i.e., surfactants or hydrophilic polymers. No polymorphic transition occurred during the microcrystallization process, but the habit of crystal formation was altered in the case of anionic surfactant.

• Journal of the Korean Ceramic Society
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• v.23 no.4
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• pp.69-77
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• 1986

Single crystals of zinc tungstates were grown by the Czochralski method. To obtain the seed crystals various methods were employed including 4 points platinum wirse which dipped the melt and the capillary action from the melt led the 3 differently oriented seeds such as [100], [010] and [001] directions. Optimum growing conditions were observed as neck diameter 2mm rotation speed 50-60 rpm maximum diameter 15mm and pulling rate 0-10 mm/hr. Dendrites covered on the olidified surface in a platinum crucible were turned out to be [001] direction because obviously this crystal has the strong [001] preferential growth habit. The (100) and (010) planes of single crystals showed the slip planes and the (010) plane showed the perfect cleavage surface.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.3
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• pp.223-232
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• 1995

Abstract Urea($(NH_2)_2CO$) and THAMP (Tris(hydroxymethyl) aminomethane phosphate) are new organic nonlinear optical materials (NLO) for the device application such as the frequency conversion of laser radiation. The single crystals of urea and THAMP have been grown by the falling temperature method and the temperature difference method. The crystal growth parameters were presented associated with the molphology of the grown crystals. Based on the solubility measurements, methanol was a suitable solvent for the growth of urea. The solubilities of urea have a positive temperature coefficient and the heat of solution of urea was estimated to be -2.58 kcal/mol. The grown crystals of urea have the preferential growth habit in the z-axis. Additives such as $NH_4_H_2PO_4$, KCL, $H_3PO_4$, $CaCl_2{\cdot}2H_2O$, $C_2H_5OH$ were used for the favourable growth in the x - and y-axis and the preventive growth in the z-axis. The moleratio of THAM and H3P04 for the solution of THAMP was 1 : 1. The solubilities of THAMP have a positive temperature coefficient. The heat of solution was estimated to be - 1.70 kcal/ mol.

• Journal of Ceramic Processing Research
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• v.19 no.5
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• pp.428-433
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• 2018

In this study, using the pilot plant activation system, the activated cement has been manufactured and then applied to the manufacturing process of mineral hydrate insulating material. The fineness of the activated cement is controlled at $5,000cm^2/g$ and $7,500cm^2/g$ and the features of mineral hydrate insulating material, using OPC and the activated cement for each degree of fineness, has been analyzed. As the result of analyzing the crystal habit of the manufactured mineral hydrate insulting material, it is analyzed that the main crystal phase of specimen is tobermorite and some quartz peak has been detected. As the degree of fineness of the activated cement increases, the height of bubble of slurry increases as well, whereas the tendency for the density character to decrease has been detected. Along with it, as the density character decreases, the compression strength has decreases, whereas the tendency for the thermal characteristic to increases has been detected. The main features of mineral hydrate insulating material, using the activated cement with the fineness of $7,500cm^2/g$, the compression strength of 0.36 MPa, and the thermal conductivity of $0.044W/m{\cdot}K$, presents the excellent features as insulation.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.224-228
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• 2012

A new $Saxifraga$ $fortunei$ cultivar 'Crystal' was bred by crossing 'Dotaerang' with light pink and light Green (RP 58D) colored petals and 'Rocksun' with light pink and light green white (RP62A + GW157A) colored petals. The selection and flower characterization were conducted from 2004 to 2007 in a greenhouse of the National Institute of Highland Agriculture. The flowering of 'Crystal' occurred from September 21 for 31 days. The number of flowers per plant was 279.0 with many flowering habit. The flower coloration was mixed light pink and green white (RP62D + GW157B) at the opening. The number of petals were 7.0, with a width of 2.1 cm and length of 1.8 cm. The plant height was 15.3 cm and number of leaves was 133.7. 'Crystal' cultivar can be used for pot flower. Fifty percent shading is a good cultural practice against direct sunlight and soft rot disease would occurs usually by over-irrigation. 'Crystal' cultivar was registered as a new variety with No. 3466 at Korea Seed and Variety Service in April of 2011 year.

• Atmosphere
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• v.25 no.2
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• pp.261-270
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• 2015

Characteristics of snowfall and snow crystal habits have been investigated in the campaign of Experiment on Snow Storms At Yeongdong (ESSAY) using radiosonde soundings, Global Navigation Satellite System (GNSS), and a digital camera with a magnifier for taking a photograph of snowfall crystals. The analysis period is 6 to 14 February 2014, when the accumulated snowfall amount is 192.8 cm with the longest snowfall duration of 9 days. The synoptic situations are similar to those of the previous studies such as the Low pressure system passing by the far South of the Korean peninsula along with the Siberian High extending to northern Japan, which eventually results in the northeasterly or easterly flows and the long-lasting snowfall episodes in the Yeongdong region. In general, the ice clouds tended to exist below around 2~3 km with the consistent easterly flows, and the winds shifted to northerly~northwesterly above the clouds layer. The snow crystal habits observed in the ESSAY campaign were mainly dendrite, consisting of 70% of the entire habits. The rimed habits were frequently captured when two-layered clouds were observed, probably through the process of freezing of super-cooled droplets on the ice particles. The homogeneous habit such as dendrite was shown in case of shallow clouds with its thickness of below 500 m whereas various habits were captured such as dendrites, rimed dendrites, aggregates of dendrites, plates, rimed plates, etc in the thick cloud with its thickness greater than 1.5 km. The dendrites appeared to be dominant in the condition of cloud top temperature specifically ranging $-12{\sim}-16^{\circ}C$. However, the association of snow crystal habits with temperature and super-saturation in the cloud could not be examined in the current study. Better understandings of characteristics of snow crystal habits would contribute to preventing breakdown accidents such as a greenhouse destruction and collapse of a temporary building due to heavy snowfall, and traffic accidents due to snow-slippery road condition, providing a higher-level weather information of snow quality for skiers participating in the winter sports, and estimating more accurate snowfall amount, location, and duration with the fallspeed of solid precipitation.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.857-861
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• 1996

The influence of rf-plasma operation on the thin film formation containing small particles for Al-Li alloys mainly have been studied as a function of Ar gas pressure and plasma power by means of a 200kV transmission electron microscope (TEM). Under the non-plasma operation, the transition from continuous thin films to clusters of grape-like small particles occurred at Ar gas pressures above 20Pa. Particles were single crystals with clear crystal habit planes. Under the plasma operation, the influence of gas pressures on the film formation at a plasma power of 5W was also examined. Thin films containing particles below 30Pa and the films containing mainly particles above 40Pa were formed. The prominent change of the average particle size was not recognized. The increase of the plasma powers at 20Pa, which formed particles under non-plasma, suppressed growth of particles, and homogeneous films containing very small particles were fabricated. The electric conductivity showed slight decrease with an increase of plasma power.

• Electrical & Electronic Materials
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• v.10 no.2
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• pp.166-171
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• 1997

The photomachinable glass-ceramics of Ag and CeO$_{2}$ added to Li$_{2}$O-Al$_{2}$O$_{3}$-SiO$_{2}$-K$_{2}$O glass system was investigated as a function of UV irradiation time. The temperature of optimum nucleation and crystal growth temperature were confirmed at 525.deg. C, 630.deg. C respectively using DTA and TMA. The phases of Li$_{2}$O.SiO$_{2}$ habit were lath-like and/or dendrite type and [002] direction of Li$_{2}$O.SiO$_{2}$ / Li$_{2}$O.2SiO$_{2}$ phases were changed according to the UV irradiation time by 400 W, 362 nm UV light source. Under that condition, the optimum UV irradiation time was 5 min.