• Journal of the Korean Ceramic Society
• /
• v.16 no.2
• /
• pp.89-98
• /
• 1979

In order to prepare ferroxplana ZnY $(Ba_2Zn_2Fe_{12}O_{22})$, which would be useful for GHz-band communication, the optimum coprecipitation condition of 1 $BaCl_{2-1} Zn(NO_3)_2-6FeCl_3$ in $NaOH-Na_2CO_3$ solution was investigated by use of a new apparatus invented in our laboratory. By freeze-drying and calcining the coprecitated hydroxide-carbonate, the very reactive powder was obtained, from which the synthesis process of ZnY and the other related crystals were investigated by means of X-ray diffraction. In results, it was found that the reactive powder containing ZnY as the major component can be prepared by this method, which may be used in manufacturing the various magnetic cores for the microwave communication.

• Journal of Power System Engineering
• /
• v.10 no.2
• /
• pp.36-40
• /
• 2006

In order to prevent the environmental pollution, the dryers are commonly used to treat sludge that one of sewages is polluting the quality of water. Generally, the drying method is various as to the property of material and use. Rotary dryer is a good apparatus to treat them. It is the way that is to make substance transmission and heat using hot air between sludge particle and heated gas. In this paper, we developed a 3-pass rotary dryer for a design program for the 3-pass rotary dryer with various conditions. The working conditions of dryer are a raw sludge feed rate, input & output water content and operation time etc.

• Journal of Power System Engineering
• /
• v.10 no.2
• /
• pp.54-61
• /
• 2006

In order to prevent the environmental pollution, the dryers are commonly used to treat sludge that one of sewages is polluting the quality of water. Generally, the drying method is various as to the property of material and use. Rotary dryer is a good apparatus to treat them. The rotary dryer is the way that is to make substance transmission and heating using hot air between sludge particles and heated gas. In this paper, we performed a numerical analysis of the inner air flow of the ANDRICH type dryer through the changing rotational speed from 3rpm to 10rpm. A PIV can be applied to research a inner flow of ANDRICH type dryer.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2000.10a
• /
• pp.471-476
• /
• 2000

Long-term behavior of reinforced clayey soil by model tests were performed to investigate the effect of reinforcement during loads and under static loads. In order to determine proper contents by weight of monofilament polypropylene fiber and calcium carbonate, the drying shrinkage and compressive strength tests had been conducted before model tests. Model tests were run on a clayey soil mixed with or without reinforcement and test specimen in test apparatus was placed in air dry for 7days before load application. In the case of fiber reinforced soil, the horizontal strain was lower than others during loads because the presence of fibers increased the soil's resistance to deformation. All of reinforced clayey soil, horizontal strain decreased as the water content decrease under static loads.

• Geomechanics and Engineering
• /
• v.16 no.6
• /
• pp.599-608
• /
• 2018

This study investigates the feasibility of adopting the results of the UC (unconfined compression) test to assess the total cohesion of the unsaturated soil. A series of laboratory tests were conducted on samples of unsaturated lateritic soils of northern Taiwan. Specifically, the unconfined compression test was combined with the pressure plate test to obtain the unconfined compression strength and its matric suction of the samples. Soil samples were first compacted at designated water content and then subjected to the wetting process for saturation and the subsequent drying process to its target suction using the apparatus developed by the authors. The correlations among the matric suction, the unconfined compression strength and the total cohesion were studied. As a result, a simplified method to estimate the total cohesion using the unconfined compressive strength is suggested. The calculated results compare reasonably with the unsaturated triaxial test results. Current results show good performance; however, further study is warranted.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.2
• /
• pp.230-235
• /
• 2005

Volatile organic components from fresh and freeze-dried onions were extracted by SDE apparatus and analyzed by GC/MS. Components of 40 and 31 were identified in fresh and freeze-dried onions respectively. These components included esters, aldehydes, ketones, alcohols and S-containing compounds. Major compounds of S-containing compounds such as 1-propanethiol, dipropyl trisulfide, and methyl propyl trisulfide in fresh onions were clearly decreased in freeze-dried onions. Then, S-containing compounds such as methyl allyl sulfide, propyl ally sulfide, dially disulfide and 3,5-diethyl-l,2,4-trithiolane and alcohols such as pentanol, hexanol and propanol were disappeared by freeze-drying. Exceptionally, ethyl acetate, dimethyl disulfide and 2-methyl-2-pentenal were increased as different trend with major S-containing compounds. (Z)-Propenyl methyl disulfide and (E)-propenyl methyl disulfide were also changed by freeze-drying in the similar pattern as mentioned above compounds.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.09a
• /
• pp.764-771
• /
• 2010

The stability analysis method of an unsaturated slope considering the suction stress was performed on the infinite sand slope. During drying and wetting processes, the Soil-Water Characteristics Curve (SWCC) of the sand with the relative density of 75% was measured using the automated SWCC apparatus. Also, the Suction Stress Characteristics Curve (SSCC) was estimated. Based on these results, the stability analysis of an unsaturated infinite slope was carried out considering the slope angle, the weathering zone and the relative change in friction angle as a soil depth. According to the result of slope stability analysis, the safety factors of slope were less than 1 when the slope angles were more than $50^{\circ}$. The safety factors of slope tend to increase with increasing the depth from the ground surface. Especially, the safety factors have a tendency to increase and decrease above near the ground water level due to the suction stress. The maximum safety factor of slope in this analysis was occurred at the Air Entry Value (AEV) of drying process. The influence range of suction stress above the ground water level can be found out and can be defined as the funicular zone which means the metric suction range from the air entry point to the point of residual volumetric water content.

• Journal of Pharmaceutical Investigation
• /
• v.41 no.1
• /
• pp.51-57
• /
• 2011

The objective of this study was to enhance the utilitization of Ibuprofen (IBU) by introducing the fast-disintegrating tablet (FDT) form. Presently, IBU is being widely used as a tablet or syrup form. But in contrast to these two formulations, IBU as FDT is not only convenient but also increases the control over the time release of the drug, noted by using Alginate beads. This study was carried out with Sodium Alginate and IBU at the ratios of 1:0, 1:0.5, 1:1, and 1:2 in order to produce a series of beads with different ratios. During the drying process of the beads, talc was added in beads to compare the effects with and without the talc. The final product was scanned with SEM imaging to determine the difference in the surface of the beads. The parameters assessed were the diameter, content assay, dissolution test and effectiveness of time-release. Direct compression method was used to prepare FDT containing IBU bead. The properties of FDT, such as hardness, disintegration time, were investigated. The dissolution profiles of FDT were tested using KP dissolution apparatus 1 (basket method). The results suggest addition of talc and drying the beads made the surface smooth and less vulnerable to clutter into chunks. The size of beads was less than 300 ${\mu}m$ which did not create a sandy feeling in the mouth. Thus, the beads formulation model made the sustained release of the drug possible, the hardness of FDT (1.25~1.50 $Kg/cm^2$) was acceptable and all the values of dissolving period were less than 30 seconds. The dissolution profile of FDT was same as that of IBU bead. The efficient dissolution profile and low price of IBU bead containing Sodium Alginate, the FDT formulation prepared from IBU bead can save the expenses and can improve the convenience of application of this drug.

• The Korea Journal of Herbology
• /
• v.31 no.3
• /
• pp.71-75
• /
• 2016

Objectives : Mori Ramulus is a young branch of Morus alba Linne, which has been used as traditional medicines for antidiarrhea, antibacteria, and antihypertension in Korea. With the basis on these medicinal activities, it is registered at the Korean Herbal Pharmacopoeia. The standard for quality control in use, however, is not yet validated.Methods : We experiment on heavy metals test, TLC, loss on drying, ash, acid-insoluble ash, contents of ethanolsoluble extracts and contents of oxyresveratrol by using the 15 samples of Mori Ramulus which are collected domestically. We tested items according to the General Test, processes and apparatus, Crude Drugs Test of KP(2011).Results : Purity test(Heavy metals) showed contents for Pb, As, Hg, and Cd range of 0.1~1.1 ppm, 0.0~0.2 ppm, 0.00~0.01 ppm, and 0.00~0.02 ppm. Identification test(Thin layer chromatography) was on comparing with morucine standard solution in R_f value, all samples showed morucine spot (dark blue, R_f : 0.3) as same as R_f value of morucine-standard solution. Loss on drying was ranged from 5.1 to 8.9 %, ash and acid-insoluble ash were between the range 3.0~6.3% and 0.3~0.8%. Contents of ethanol-soluble extracts was ranged from 6.2 to 12.0%. Content of oxyresveratrol was ranged from 0.01 to 0.16 % based on the oxyresveratrol standard curve.Conclusions : We sincerely hope that this study will be contributed to the standardization and quality control of Korean herbal medicines.

• Korean Journal of Medicinal Crop Science
• /
• v.24 no.6
• /
• pp.451-457
• /
• 2016

Background: Leonurine is a the aerial part of Leonurus japonicus Houttuyn, which has been used as a traditional medicines and is registered in the Korean Pharmacopoeia. Methods and Results: In the present study we performed a heavy metals and thin layer chromatography and measured loss on drying, as well as the contents of total ash, acid-insoluble ash, ethanol soluble compounds, and leonurine, using 15 domestically collected L. japonicus samples. The methods were performed according to the 'crude drugs test of the general test, processes and apparatus', published by MFDS, Korea (2014). The purity test (heavy metals) indicated that levels of Pb and Hg were 0.35 - 3.64, and 0.001 ppm, respectively, whereas the levels of As and Cd were undetectable, and stachydrine was identified by thin layer chromatography ($R_f$ : 0.15). We found that 5.93 - 10.62% (average: $8.58{\pm}1.8%$) of the sample mass was lost during drying, and the contents of total ash, acid-insoluble ash, ethanol soluble compounds, and leonurine were 7.87 - 10.84% (average: $9.62{\pm}0.82%$), 0.99 - 1.76% (average: $1.38{\pm}0.24%$), 16.70 - 23.11% (average: $19.49{\pm}2.14%$) and 0.04 - 0.17% (average: $0.11{\pm}0.04%$) respectively. In addition, HPLC profiling detected leonurine (5.94 min), rutin (16.43 min) and myricetin (26.78 min). Conclusions: We hope that this the rusult of the present study will contribute to the standardization and quality control of Korean herbal medicines.