• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.327-335
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• 2009

In the seismic region, non-ductile structures often form soft story and exhibit brittle collapse. However, structure demolition and new structure construction strategies have serious problems, as construction waste, environmental pollution and popular complain. And these methods can be uneconomical. Therefore, to satisfy seismic performance, so many seismic retrofit methods have been investigated. There are some retrofit methods as infill walls, steel brace, continuous walls, buttress, wing walls, jacketing of column or beam. Among them, the infilled frames exhibit complex behavior as follows: flexible frames experiment large deflection and rotations at the joints, and infilled shear walls fail mainly in shear at relatively small displacements. Therefore, the combined action of the composite system differs significantly from that of the frame or wall alone. Purpose of research is evaluation on the seismic performance of infill walls, and improvement concept of this paper is use of SHCCs (strain-hardening cementitious composites) to absorb damage energy effectively. The experimental investigation consisted of cyclic loading tests on 1/3-scale models of infill walls. The experimental results, as expected, show that the multiple crack pattern, strength, and energy dissipation capacity are superior for SHCC infill wall due to bridging of fibers and stress redistribution in cement matrix.

• Membrane Journal
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• v.27 no.3
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• pp.248-254
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• 2017

In order to secure the reliability of pathogenic microorganisms such as Cryptosporidium and Giaridia, which are chlorophilic protozoans, membrane filtration systems have been widely used in water purification process. hese integrity tests are classified into direct and indirect methods. Based on the bubble point theory, the pressure-based test in the direct method is presented in the USEPA Guidance Manual with sensitivity to detect a minimum size of pathogenic microorganisms of $3{\mu}m$ or more. Indirect methods are widely used in that they are capable of continuous operation in on-line state, but there is a very low sensitivity of damage detection compared to the direct method, and there is a limit that can not specify the damage area, so it is necessary to improve this sensitivity. In this study, we compared the LRVDIT and UCL values according to the type of membrane defect, number of fiber breaks, and initial set pressure value through the Integrity Test by Pressure Decay Test (PDT).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.221-228
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• 2001

This study was carried out to investigate the effect of germination condition and drying temperature on growth and physicochemical properties of brown rice. Three brown rice seeds of Ilpumbyeo, Dasanbyeo and Heugjinjubyeo were stored at room temperature for six weeks to test the time-sequence germination viability. Relatively stable germination ratio was maintained until 2 weeks after storage. However, 3 weeks after storage, germination ratio of brown rice seeds started to decrease rapidly and their germination ratio was lower than 80%. For this reason, brown rice was recommended for seeding within 2 weeks after hulling. During the initial 5 days, germination ratio of 24 hours pre-soaking brown rice was higher about 2-3% than that of non-soaking brown rice. The $25^{\circ}C$ was considered as the most favorable temperature for brown rice germination, because of the high germination ratio and desirable coleoptile growth of the brown rice, and little seed rotting symptoms. The scanning electron micrographs showed the structural differences between hot-air dried and freeze dried germinated-brown rice kernel. In the freeze dried germinated-brown rice, seed coat (pericarp, tegmen and aleurone layer) was mechanically disrupted from the endosperm, and many cleavages were observed among starch storing cells and starch granules. The endosperm of freeze-dried brown rice kernels formed the sponge-like structures and showed the fragile traits. For this reason, hot-air drying is considered as more suitable method than freeze drying for germinated-brown rice. The crude protein and amylose contents were slightly changed, but there were no significant differences during the germination period. Crude fiber content was decreased, but crude Int and total amino acid contents were increased as seeding days increased. A rapid increase in $\alpha$-amylase activities of germinating brown rice was observed at S days after seeding, and $\alpha$-amylase activities were decreased from 8 days after seeding. Total free sugar contents were decreased during the germination period. There was continuous decline in the contents of sucrose and glucose until 8 days after seeding, but fructose and maltose content were gradually increased from the 5 days after seeding.

• Journal of Acupuncture Research
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• v.24 no.6
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• pp.45-61
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• 2007

Objectives : The purpose of this study is to observe the effects of Carthami Flos herbal-acupuncture (CF-HA) at Joksamni($ST_{36}$) on arthritis in mice induced by Collagen II. Methods : The author performed several experimental items, including arthritis evaluation, change in weight, spleen size and stenosis rate, change in cytokine level, IgG, IgM and anti-collagen II, change of immunocyte count and histological change of the CIA mouse joint. Conclusions are as follows: Results : 1. In the CF-HA, the arthritis index and rate and the incidence of arthritis were decreased as the experiment proceeded. 2. In the CF-HA, spleen swell and stenosis, joint edema and change were decreased. 3. In the CF-HA, the level of $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ and $IFN-{\gamma}$ in blood serum were significantly decreased. 4. In the CF-HA, the level of IgG, IgM and anti-collagen II were decreased. 5. In the CF- HA, $IFN-{\gamma}$, $IFN-{\gamma}/IL-4$, IL-10 of the culture fluid was decreased. 6. In the CF-HA, the cell rate of $CD3e^+$ and $CD45R^+$, $CD4^+$ and $CD8^+$, $CD4^+/CD25^+$ in spleen was similar to the cell rate of the normal group. 7. In the CF-HA, the cell rate of $CD4^+/CD25^+$, $CD45R^+/CD69^+$ in a lymph node was decreased as in the normal group. 8. In the CF-HA, the cell rate of $CD3^+/CD69^+$, $CD11b^+/Gr-1^+$ in joints was decreased as in the normal group. 9. In the CF-HA, the cartilage destruction and the inflammation cell growth in the H&E stain were decreased. The collagen fiber in the M&T stain were less destructed, therefore the result was similar to the normal group. Conclusions : These results suggest that CH-HA at $ST_{36}$ has an effect in controlling immune reaction and suppressing inflammation in rheumatoid arthritis therefore, the continuous flow of the following study is expected.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.93-99
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• 2000

Treatment of shaving scrap, a chrome containing solid scrap generated by leather manufacturing process, has been so far depended on mainly incineration, soil landfill and ocean dumping, which give bad impact on environment and cause pollution. Shaving scrap generates from the mechanical work for controlling the final thickness of leather and its main components are collagen protein and pan of chromium compound. For the purpose of reusing this leather waste as resources, researches in connection with collagen fiber recovery, gelable protein recovery and liquid fertilizer is being speedily progressed. In the experiment, shaving scrap went through wet pulverizing treatment by physical and chemical methods. Then, making the leather sheet evenly, it is mixed with natural latex and every kind of binding materials in the container, and the mixtures were passed through experimental hydraulic press machine and applied to Fourdrinier machine respectively. Lastly, a test for fading out physical strength and properties of multiple-purpose of leather-like material was performed on a continuous leather sheet prepared by the experiment. In result, the physical strength and properties of leather-like material showed noticeable differences according to mixing ratio of binding materials, beating methods and the Ends of binding materials selected, and generally tear strength was the weakest property among others. Also, by the pilot scale experiment in sequence, it was possible to manufacture recycled goods made of soft and hard types of leather-like material with various performances.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.327-349
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• 2010

This study was carried out to investigate the distribution of vascular plants and their use from 2007 to 2009 in Mt. Unmum(Cheongdo-gun, Gyeongsangbuk-Do). The vascular plants were summarized as 605 taxa including 98 families, 304 genus, 514 species, 3 subspecies, 68 varieties, and 20 forma. Among the investigated 605 taxa, 21 rare and endangered plants, 29 Korean endemic plants were included. Based on the list of specially designated plants by Ministry of Environment, 70 taxa included Iris odaesanensis and Gastrodia elata were recorded in the investigated area. The naturalized plants were identified as 23 taxa and the percent of naturalized index(NI) was 3.8% of total 605 taxa vascular plants. Usage of 605 taxa were consists of 225 taxa(37.2%) of edible plants, 191 taxa(31.6%) of medicinal plants, 64 taxa(10.6%) of ornamental plants, 46 taxa(7.6%) of pasture plants, 18 taxa(3.0%) of timber plants, 14 taxa(2.3%) of fiber plants, and 3 taxa(0.5%) of industrial plants. To management of natural resource, we suppose that it is required to establish an ecological learning area to minimize human disturbance and an effective managemet strategy by continuous monitoring for ecosystem change.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.149-158
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• 2010

Recently, numerous construction techniques for repairing and strengthening methods for above ground or air exposed concrete structure have been developed. However repairing and strengthening methods for underwater structural members under continuous loading, such as piers and steel piles need the further development. Therefore, this study develops an aqua epoxy, which can be used for repairing and strengthening of structural members located underwater. Moreover, using the epoxy material and strengthening fibers, a fiber reinforced composite sheet called Aqua Advanced FRP (AAF) for underwater usage is developed. To verify and to obtain properties of the material and the performance of AAF, several tests such as pull-off strength test, bond shear strength test, and chemical resistance test, were carried out. The results showed that the developed aqua epoxy does not easily dissolve in wet conditions and does not create any residual particle during hardening. In spite of underwater conditions, it showed the superior workability, because of the high viscosity over 30,000 cps and adhesion capacity over 2 MPa, which are nearly equivalent to those used in dry conditions. In case of the chemical resistance test, the developed aqua epoxy and composite showed the weight change of about 0.5~1.0%, which verifies the superior chemical resistance.

• Journal of Chest Surgery
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• v.40 no.2 s.271
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• pp.97-102
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• 2007

Background: Endovenous laser treatment has recently been introduced as a less invasive technique, with many good results reported, A 980-nm diode laser was used on the great saphenous vein (GSV) occlusions in patients with varicose veins, due to GSV reflux, and the therapeutic effects analyzed. Material and Method: Between September 2003 and February 2006, 238 patients (332 cases) with GSV reflux underwent endovenous laser treatment with a 980-nm diode laser. Operative procedures were simultaneous endovenous laser treatment and ambulatory phlebectomy. The preoperative clinical findings, postoperative complications and postoperative duplex US follow up results at 1 and 3 months were reviewed. Result: Postoperative complications were ecchymosis in almost cases, paresthesia 68 cases (20.5%) and skin burn in 3 cases (0.9%). Follow up duplex US revealed 26 and 10 cases at 1 and 3 months of GSV reflux or partial recanalization, with therapeutic success rates of 91.3 and 87.9%, respectively. Conclusion: The treatment of GSV occlusion with an endovenous laser is less invasive than traditional GSV stripping, but relatively high recanalization was experienced, possibly due to inadequate laser power, laser fiber pullback speed or an extremely dilated GSV. However, continuous attempts will be required to reduce the recanalization after the procedure, with accurate follow up using duplex US.

• Journal of the Korea Concrete Institute
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• v.19 no.1
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• pp.121-130
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• 2007

To investigate the enhancement in strength and deformation capacities of concrete confined by FRP composites, tests under axial loads were carried out on three groups of thirty six short columns in circular section with diverse GFRP confining reinforcement. The major test variables considered include fiber content or orientation, wrap or tube type by varying the end loading condition, and continuous or discontinuous confinement depending on the presence of vortical spices between its two halves. The circumferential FRP strains at failure for different types of confinements were also investigated with emphasis. Various analytical models capable of predicting the ultimate strength and strain of the confined concrete were examined by comparing to observed results. Tests results showed that FRP wraps or tubes provide the substantial increase in strength and deformation, while partial wraps comprising the vertical discontinuities fail in an explosive manner with less increase in strength, particularly in deformation. A bilinear stress-strain response was observed throughout all tests with some variations of strain hardening. The failure hoop strains measured on the FRP surface were less than those obtained from the tensile coupons in all tests with a high degree of variation. In overall, existing predictive equations overestimated ultimate strengths and strains observed in present tests, with a much larger scatter related to the latter. For more accuracy, two simple design- oriented equations correlated with present tests are proposed. The strength equation was derived using the Mohr-Coulomb failure criterion, whereas the strain equation was based on entirely fitting of test data including the unconfined concrete strength as one of governing factors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.56-63
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• 2018

The management of Combined Sewer Overflows(CSOs) and Separated Sewer Overflows(SSOs) discharge directly to the effluent system in an untreated state, which occurs when the facility capacity is exceeded due to heavy rain, has become an important issue in recent years as the heavy rain becomes a regular phenomenon. Despite the continuous development of filtration technology, targeting densely populated urban areas, CSOs are rarely applied. Therefore, this study was carried out to optimize the process to apply CSOs in a pilot-scale horizontal flow filtration system with a rope-type synthetic fiber. The research was carried out in two steps: a preliminary study using artificial samples and a field study using sewage. In the preliminary study using an artificial sample, head loss of the filter media itself was analyzed to be approximately 1.1cm, and the head loss was increased by approximately 0.1cm as the linear velocity was increased by 10m/hr. In addition, the SS removal efficiency was stable at 81.4%, the filtration duration was maintained for more than 6 hours, and the average recovery rate of 98% was obtained by air backwashing only. In the on-site evaluation using sewage, the filtration duration was approximately 2 hours and the average removal efficiency of 83.9% was obtained when belt screen (over 450 mesh) was applied as a pre-treatment process to prevent the premature clogging of filter media. To apply the filtration process to CSOs and SSOs, it was concluded that the combination with the pre-treatment process was important to reinforce the hydraulic dimension for the stable maintain of operation period, rather than efficiency. Compared to the dry season, the quality of incoming sewage was lower in the rainy season, which was attributed to the characteristics of the drainage area with higher sanitary sewerage. In addition, the difference in removal efficiency according to the influent quality of the wet season and dry season was small.