• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.79-89
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• 2022

With the wide use of greenhouses, the working hours have been increasing inside the greenhouse for workers. In the closed ventilated greenhouse, the internal environment has less affected to external weather during making a suitable temperature for crop growth. Greenhouse workers are exposed to organic dust including soil dust, pollen, pesticide residues, microorganisms during tillage process, soil grading, fertilizing, and harvesting operations. Therefore, the health status and working environment exposed to workers should be considered inside the greenhouse. It is necessary to secure basic data on particulate matter (PM) concentrations in order to set up dust reduction and health safety plans. To understand the PM concentration of working environment in greenhouse, the PM concnentrations were monitored in the cut-rose and Hallabong greenhouses in terms of PM size, working type, and working period. Compare to no-work (move) period, a significant increase in PM concentration was found during tillage operation in Hallabong greenhouse by 4.94 times on TSP (total suspended particle), 2.71 times on PM-10 (particle size of 10 ㎛ or larger), and 1.53 times on PM-2.5, respectively. During pruning operation in cut-rose greenhouse, TSP concentration was 7.4 times higher and PM-10 concentration was 3.2 times higher than during no-work period. As a result of analysis of PM contribution ratio by particle sizes, it was shown that PM-10 constitute the largest percentage. There was a significant difference in the PM concentration between work and no-work periods, and the concentration of PM during work was significant higher (p < 0.001). It was found that workers were generally exposed to a high level of dust concentration from 2.5 ㎛ to 35.15 ㎛ during tillage operation.

• Korean journal of applied entomology
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• v.43 no.2
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• pp.135-141
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• 2004

This study was carried out to review the distributional data of Dorcus hopei in Korea and to investigate ecological characteristics to develop a mass rearing technique of the species. The coupling period of the male and female was needed at least 2 weeks in condition of 6 months after emergence, and the optimal sex ratio for oviposition was 2♀：1♂. Eggs were laid singly, up to 27.3 per female. The pre-ovipostion period was average 147.3 days, egg-period was 15.6 days on the average, and oviposition period was at least 120 days. The optimum size of oviposition room was 55${\times}$40${\times}$35 cm with 3-4 oviposition-trees cut in size of 15${\times}$15 cm. Quercus acutissima was highly preferred for the oviposition. Developing period of each instar in the insectary (25$^{\circ}C$, 75％ R.H.. 16L：8D) was 24.1 days for the 1st instar,29.8 days for the 2nd, and 131.2 days for the 3rd instar, and 28.9 days for the pupa. The longevity of adults was longer than 35 months. The period of induced dormancy was needed at least 3-4 months.

• Archives of Plastic Surgery
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• v.37 no.2
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• pp.137-142
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• 2010

Purpose: Tumor ablation and traumatic intractable ulceration of the plantar surface of the foot results in skin and soft tissue defects of the weight-bearing sole. Simple skin grafting is not sufficient for reconstruction of the weight-bearing areas. Instead, the island medial plantar flap (instep flap) and distally-based island medial plantar flap was used for proper reconstruction of the weight bearing area. However, there are some disadvantages. In particular, an island medial plantar flap has a short pedicle limiting the mobility of the flap and the distally-based island medial plantar flap is based on a very small vessel. We investigated whether good results could be obtained using a reverse island medial plantar flap based on the lateral plantar vessel as a solution to the above limitations. Methods: Three patients with malignant melanoma were cared for in our tertiary hospital. The tumors involved the lateral forefoot, the postero-lateral heel, and the medial forefoot area. We designed and harvested the flap from the medial plantar area, dissected the lateral and medial plantar artery and vena comitans, and clamped and cut the vessel 1 cm proximal to the branch from the posterior tibial artery and vena comitans. The medial plantar nerve fascicles of these flaps anastomosed to the sural nerve, the 5th interdigital nerve, and the 1st interdigital nerve of each lesion. The donor sites were covered with skin grafting. Results: The mean age of the 3 subjects was 64.7 years (range, 57 - 70 years). Histologically, all cases were lentiginous malignant melanomas. The average size of the lesion was $5.3\;cm^2$. The average size of the flap was $33.1\;cm^2$. The flap color and circulation were intact during the early postoperative period. There was no evidence of flap necrosis, hematomas or infection. All patients had a normal gait after the surgery. Sensory return progressively improved. Conclusion: Use of an island medial plantar flap based on the lateral plantar vessel to the variable weight-bearing sole is a simple but useful procedure for the reconstruction of any difficult lesion of the weight-bearing sole.

• Journal of Pharmaceutical Investigation
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• v.27 no.4
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• pp.303-311
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• 1997

Proliposomal patch of clenbuterol, ${\beta}_2-agonist$ bronchodilator, was prepared and its feasibility as a novel transdermal drug delivery system was examined. Proliposomal granules containing clenbuterol was prepared by a standard method using sorbitol and lecithin with (Rx 2) or without cholesterol (Rx 1). The porous structure of sorbitol in the proliposomes was maintained allowing tree flowability of the granules. Following contact with water, the granules were converted probably to liposomes almost completely within several minutes. It indicates that proliposomes may be hydrated, when they are applied on the skin under occlusive condition in vivo, by the sweat to form liposomes. Clenbuterol release from Rx 1 and Rx 2 proliposomes to pH 7.4 isotonic phospate buffer (PBS) across cellulose membrane (mol. wt. cut-off of 12000-14000) was retarded significantly compared with that from the mixture of clenbuterol powder and blank proliposomes. Interestingly, proliposomes prepared with lecithin and cholesterol (i.e., Rx 2 proliposomes) showed much more retarded release of clenbuterol than proliposomes prepared only with lecithin (i.e.. Rx 1 proliposomes), indicating that clenbuterol release from proliposomes can be controlled by the addition of cholesterol to the proliposomes. Proliposomal patches were prepared using PVC film as an occlusive backing sheet, two sides adhesive tape (urethane, 1.45 mm thickness) as a reservoir for proliposome granules and Millipore MF-membrane (0.45 mm pore size) as a drug release-controlling membrane. Rx 1 or Rx 2 proliposomes containing 4.6 mg of clenbuterol were loaded into the reservoir of the patch. Clenbuterol release from the patches to pH 7.4 PBS was determined using USP paddle (50 rpm)-over-disc release method. Clenbuterol release from the proliposomal patches was much more retarded even than from a matrix type clenbuterol patch (Boehringer Ingelheim ltd). Being consistent with clenbuterol release from the proliposomal granules, the release from the patches was highly dependent on the presence of cholesterol in the proliposomes : Patches containing Rx 2 proliposomes showed several fold slower drug release than patches containing Rx 1 proliposomes. When the patch containing Rx 1 proliposomes was applied on to the back of a hair-removed rat, clenbuterol concentration in the rat blood was maintained during 6-72 hrs. Transdermal absorption of clenbuterol from the patch was accelerated when the patch was prehydrated with 50 ml of pH 7.4 PBS before topical application. Above results indicate that sustained transdermal delivery of clenbuterol is feasible using proliposomal patches if the cholesterol content and pore size of the release rate-controlling membrane of patches, for example, are appropriately controlled.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.130-133
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• 2003

A method for separating heme-iron from hemoglobin (Hgb) hydrolysate by dialysis was developed. Recovery of heme-iron increased with increasing Hgb concentration, whereas rejection of peptide and separation effciency expressed by HP ratio (heme-iron/peptide) did not show significant differences. HP ratio increased with increases in the degree of hydrolysis of Hgb and $KH_2PO_4$ concentrations of dialysis solution. Recovery of heme-iron decreased with increase in the pH of dialysis solution due to wash-out of heme-iron across the dialysis membrane caused by increase in solubility of heme-iron. Rejections of peptide were 74.5 and 87.5% (2 and 5 kDa of cut off size, respectively), whereas recovery of heme-iron decreased from 86.5 (2 kDa) to 63.1% (25 kDa). Amounts of heme-iron and peptide of dried heme-iron product were 21.7 and 77.0%, and HP ratio and production yield were 28.2 and 6.5%, respectively.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.303-310
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• 2013

Thyroid nodular disease is the most frequently appeared in thyroid disease. Thyroid ultrasonography offers location of nodules, size, the number, information of internal echo characteristic. Thus, it makes possible to sort high-risk nodule containing high possibility about thyroid cancer and to induct precisely when take a Fine Needle Biopsy Aspiration. On thyroid nodule, the case which is diagnosed as malignant is less than 5% but screening test is very important on ultrasound and also must be reduced unnecessary procedure. Therefore, in this study an approach for describing a region is to quantity its texture content. We applied TFA algorithm on case which has been pathologically diagnosed as papillary thyroid cancer. we obtained experiment image which set the ROI on ultrasound and cut the $50{\times}50$ pixel size, histogram equalization. Consequently, Disease recognition detection efficiency of GLavg, SKEW, UN, ENT parameter were high as 91~100%. It is suggestion about possibility on CAD which distinguishes thyroid nodule. In addition, it will be helpful to differential diagnosis of thyroid nodule. If the study on additional parameter algorithm is continuously progressed from now on, it is able to arrange practical base on CAD and it is possible to apply various disease in the thyroid US.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.235-243
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• 2002

Ni-base superalloys are used extensively in industry, both in aeroengines and land based turbines. About 60% by weight of most modern gas turbine engine structural components are made of Ni-base superalloys. To satisfy practical demands, the efficiency of gas turbine engines has been steadily and systematically increased by design modifications to handle higher turbine inlet or firing temperatures. However, the increase in operating temperatures has lead to a decrease in the life of components and increase in costs of replacement. Moreover, around 80% of the large frame size industrial/utility gas turbines operating in the world today were installed in the mid-sixties to early seventies and are now 25 to 30 years old. Consequently, there are greater opportunities now to repair and refurbish the older models. Basically, there are two major factors influencing the weldability of the cast alloys: strain-age cracking and liquation cracking. Susceptibility to strain-age cracking is due to the total Ti plus AI content of the alloy; Liquation cracking is due either to the presence of low melting constituents or constitutional liquation of constituents. Though Rene 41 superalloy has 4.5wt.% total Ti and Al content and falls just below the safe limit proposed by Prager et al., controlled grain size and special heat treatments are needed to obtain crack-free welds. Varying heat treatments and filler materials were used in a laboratory study, then the actual welding of service parts was carried out to verity the possibility of crack-tree weld of components fabricated from Rene 41 superalloy. The microstructural observations indicated that there were two kinds of carbides in the FCC matrix. MC carbides were located along the grain boundaries, while M$_{23}$C$_{6}$ carbide was located both inter and intra granularly. Two kinds of filler materials, Rene 41 and Hastelloy X were used to gas tungsten arc weld a patch into the sheet metal, along with varying pre-weld heat treatments. The microstructure, hardness and tensile tests were determined. The service distressed parts were categorized into three classes: with large cracks, with medium cracks and with small or no visible cracks. No significant difference in microstructure among the specimens was observed. Specimens were cut from the corner and the straight edge of the patch repair, away from the corner. The only cracks present were found to be associated with inadequate surface preparation to remove oxidation. Guidelines for oxide removal and the welding procedures developed in the research enabled crack-free welds to be produced.d.

• Korean Journal of Medicinal Crop Science
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• v.2 no.2
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• pp.110-113
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• 1994

This experiment was carried out to establish the optimum planting density for producing high tuber yield of Liriope platyphylla WANG and TANG using the recommended variety 'Maekmoondong 1'. Different planting distances such as $20cm\;/rows{\times}10cm\;/hill,\;30{\times}10,\;30{\times}30$ and different plant numbers like 2 plants /hill, 4,6 were combined to make different planting densities. Upper growth state was better by further spacing in case of leaf size, tiller number, fresh leaf weight per each hill. But unlike upper growth state tuber number and. its yield were highest at 372kg /10a and 43No. /hill. respectively with the planting density, $30cm{\times}10cm$, 6 plants per hill. Over growth of vegetative parts cut down the tuber yield. Correlations among leaf size, tiller number, leaf weight and root weight were positive. Tuber number was positively correlated with all characteristics except root weight.

• Tunnel and Underground Space
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• v.17 no.5
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• pp.350-359
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• 2007

Most large cut slopes of open pit mines, roadways, and railways are steeply inclined and composed with rocks that do not contain soils. However, these rock slopes suffer both weathering and fragmentation. In the case of steep slopes, falling rock and collapse of a slope may often occur due to surface erosion. Cast-in place concrete and rubble work are the most widely used earth structure-based pressure supports that act as restraints against the collapse of the rock slope. In order to overcome the shortcomings of conventional retaining walls, a segmental grid retaining wall is being used with connects precasted segments to construct the wall. In this study, laboratory model test was conducted to estimate deformation behavior of segmental grid retaining wall with configuration of rear strecher, height and inclination of the wall. In order to examine the behavior characteristics of a segmental grid retaining wall, this research analyzes the aspects of spacial displacement through relative displacement according to change in the inclination of the wall. Also, the walls behavior according to the formation and status of the rear stretcher which serves the role of transferring the load from the header and the stretcher which make up the wall, the displacement of backfill materials in the wall, and the location of the maximum load were surveyed and the characteristics of displacement in the segmental grid retaining wall were observed. The test results of the segmental grid retaining wall showed that there was a sudden increase in failure load according to the decrease in the wall's height and the size of the in was greatly decreased. Furthermore, it revealed that with identical inclination and height, the structure of the rear stitcher did not greatly affect the starting point or size of maximum horizontal displacement, but rather had a stronger effect on the inclination of the wall.

• Journal of the Korean Magnetics Society
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• v.5 no.1
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• pp.42-47
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• 1995

FeN thin films for inductive recording heads were sputter deposited using RF diode sputtering mehtod from a pure iron target onto 7059 glass substrates, and their magnetic properties were measured. The magnetic properties were greatly affected by film thickness, gas pressure, sputter power and flow ratio of $N_{2}$ to Ar. Single layer FeN films with their thickness varied from $1,000\;{\AA}$ to $6,000\;{\AA}$ were doposited. 800 W sputter power, 3 mT gas pressure, $N_{2}$ to Ar flow ratio of 6.6 : 100 were the sputtering conditions. Up to 7 layers of FeN films having total thickness of $6,000\;{\AA}$ were deposited using $SiO_{2}$ of $30\;{\AA}$ thickness as intermediate layers and their coercivity and saturation magnetization were measured. The sputtering conditions were the same as those in the single layer films. Easy axis coercivity of the single layer FeN films gradually decreased as their thickness was increased, but for the films with their thicknesses above $3,000\;{\AA}$, the coercivity changed very little. As the number of the FeN layers were increased, the coercivity decreased We estimated the grain size of FeN films from the FWHM (Full Width at Half Maximum) of X-ray diffraction peaks. The grain size steadily decreased from about $200\;{\AA}$ to $120\;{\AA}$ as the number of layers were increased. Minimum hard axis coercivity of 0.4 Oe was obtained when the number of layers was four. Maximum relative permeability was 2,900 when the number of layers was three. The cut off frequeocy of the multilayer films were above 100 MHz.