• Title/Summary/Keyword: Permeability Factors

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Implementation of Infinite Boundary Condition Considering Superposed Theory on SVE Remediation System (토양증기추출복원 시스템에서 중첩이론을 고려한 무한 경계조건 실행)

  • Park, Jeong-Jun
    • Journal of the Korean Geosynthetics Society
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    • v.6 no.3
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    • pp.9-16
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    • 2007
  • Soil vapor extraction (SVE) is an effective and cost efficient method of removing volatile organic compounds (VOCs) and petroleum hydrocarbons from unsaturated soils. Incorporating PVDs in an SVE system can extend the effectiveness of SVE to lower permeability soils by shortening the air flow-paths and ultimately expediting contaminant removal. With this approach, the real bounded system is replaced for the purposes of analysis by an imaginary system of infinite areal extent. The boundary conditions for the contaminant remediation model test include constant head and no flow condition. Due to these parallel boundaries conditions, image wells should be developed in order to maintain the condition of no flow across the impermeable boundary. It is also assumed that the flow is drawdown along the constant head boundary condition. The factors contributing to the difference between the theoretical and measured pressure heads were also analyzed. The flow factor increases as the flow rate is increased. The flow rate is the most important factor that affects the difference between the measured and theoretical pressure heads.

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Evaluation indicators for the restoration of degraded urban ecosystems and the analysis of restoration performance (훼손된 도시생태계 생태복원 평가지표 제시 및 복원성과 분석)

  • Sohn, Hee-Jung;Kim, Do-Hee;Kim, Na-Yeong;Hong, Jin-Pyo;Song, Young-Keun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.6
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    • pp.97-114
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    • 2019
  • This study aims to analyze the effect of urban ecosystem restoration projects by evaluating the short-term restoration performance of the project sites, from both qualitative and quantitative evaluations. In this study, for the qualitative evaluation, we derived the evaluation frame from previous studies and literature. For the quantitative evaluation, the changes in ecological connectivity after the restoration project were described using landscape permeability and network analysis. In addition, changes in habitat quality after the restoration project were evaluated by using InVEST Habitat Quality Model. These evaluations were applied to the three natural madang (ecological restoration) projects and two ecosystem conservation cooperation projects. As a result, three categories, 10 indicators, and 13 sub-indicators were derived from literature as the evaluation frame for this study. In the case of quantitative evaluation of restoration performance, habitat quality increased by 45% and ecological connectivity by 37% in natural-madang, and habitat quality by about 12% and ecological connectivity by about 19% in ecosystem conservation cooperation projects. This implies that the ecological restoration project can increase the ecological connectivity and the habitat quality of degraded sites even in a short period of time by improving the land-cover and land use. The results by applying the evaluation frame indicated that ecological and environmental factors and the ecological functions were improved by the restoration works, even though the magnitude of performances were diverse depending on the specific evaluation items, project type, and site characteristics. This study clarified that the success of ecological restoration project should be assessed by both of the short-term and long-term goals, which can be achieved by the maintenance and sustainable management, respectively.

Preference of Bedding Fabric according to Size and Spacing of Dot Pattern (도트 무늬의 크기와 간격에 따른 침구류 직물 선호도에 대한 연구)

  • Sa, A-Na;Lee, Sun-Young;Kim, Jung-Hwa;Lee, Jung-Soon
    • Fashion & Textile Research Journal
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    • v.20 no.5
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    • pp.592-599
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    • 2018
  • The purpose of this study is to investigate consumer needs, image sensibility and preference of bedding fabric according to size and spacing of dot pattern. 18 kinds of dot pattern fabrics were designed with different diameters(6, 8, 10cm) and distances(4, 7, 10cm) in regular arrangement of diamond figure. The subjects were 162 male and female university students. The data were analyzed by SPSS 24.0. Fabrics were assessed subjectively using a 5-point scale 17 consumer needs and 33 sensory descriptors. The most consumer's needs for bedding fabric was shown to be functionality of bedding including hygiene, touch, warmth, ease of washing and management, air permeability, and hygroscopicity. The other parameters of consumer's needs were shown to be physical property and design parameter. The results of analysis of the dimension of image sensibility for fabrics with different size and spacing of dots are derived from six factors including joyfulness, coziness, uniqueness, charm, femininity, and complexity. As a result of analysis of preference with fabric kinds, there was a significant difference in preference with fabrics. The preferred fabrics were characterized by the pattern and the base fabric being striking three-dimensionally with 1/3 twill and 3/1 twill fabric. Sensory descriptors related to joyful image and unique image were analyzed as evaluation terms that can distinguish the preferences of fabrics. Correlation analysis showed the fabrics are preferred as the difference in luminance and reflectance between the base and pattern of the fabric become larger and the spacing of patterns become closer.

Review for Clinical Studies of Oriental Medicine on the Treatment of Ovarian Hyperstimulation Syndrome (난소과자극증후군의 치료에 관한 한의 임상 연구 고찰)

  • Ku, Su-Jeong;Hwang, Deok-Sang;Lee, Jin-Moo;Lee, Chang-Hoon;Jang, Jun-Bock
    • The Journal of Korean Obstetrics and Gynecology
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    • v.33 no.3
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    • pp.60-79
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    • 2020
  • Objectives: This review plans to assess the efficacy and effectiveness of oriental medicine for the treatment of Ovarian Hyperstimulation Syndrome (OHSS) through literature research and overview. Methods: Database searching was conducted to identify relevant randomized controlled trials (RCTs) on oriental medicine for the treatment of Ovarian Hyperstimulation Syndrome. Studies were searched from Journal of Korean Obstetrics and Gynecology, Korean Medical Database, Korean studies Information Service System, China National Knowledge Infrastructure, Cochrane library, PubMed and EmBase up to 21st May, 2020. Results: Seventeen studies were finally selected. Fifteen studies intervened with oral Chinese herb medicine, two studies intervened with acupuncture and moxibustion. Nine studies concluded that intervention with oriental medicine significantly relieved OHSS symptoms. Three studies reporting ovary diameter, four studies reporting abdominal circumference and other four studies reporting pelvic effusion showed significant reduction compared to control groups. Six studies showed significantly shorter duration for hospitalization in intervention groups. Only one study showed significantly higher pregnancy rate. Factors related with vascular permeability and blood cell coagulation were significantly lowered in intervention groups in general. Conclusions: From seventeen studies, oriental medicine relieved OHSS symptoms and showed treatment effectiveness. Further strictly designed studies and long-term observed studies are needed to establish evidences.

An Evaluation of the Phenomenon of Heat-Island Effect by Multi-Criteria Methods (다항목 평가기법의 적응을 통한 열섬현상의 평가)

  • Lee Jung-Min;Do Hu-Jo;Ra Jung-Hwa;Kim Soo-Bong;Jung Eung-Ho
    • Journal of Environmental Science International
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    • v.14 no.11
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    • pp.1005-1014
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    • 2005
  • The purpose of this research was to present multi-criteria which were related to the heat island and find methods which decreased heat island affection on the ecological landscape planning. The results of this study were as follows. According to the analysis of surface temperatures, the first grade was the outside-city like a mountain and its temperature was less than $13.0^{\circ}C$. The fifth grade was the downtown, industrial area and its temperature was more than $26.9^{\circ}C$. Therefore, the result was seen the serious heat-island effect. The results of field survey, the closer to the first grade, the higher the value of green coverage. The closer to the fifth grade, the higher the value of impermeability surface, paving materials and colors. According to the correlation analysis, the temperature had high correlation with impermeability surface, paving materials and colors. According to the simple regression analysis, permeability surface, green coverage, topography, impermeability surface, paving materials f: colors, human impact related with surface temperatures. To plan for the decrease of Heat-Island Effect needed the extension of green space, decrease of impermeability surface. This research suggested data for urban green plan and decrease of heat island effect, but there was a limit to get the objective method for grade classification because of lacking in the basic data, the research of multi-criteria will be accomplished continuously.

Experimental and Numerical Studies for Sedimentation and Consolidation Characteristics of Dredged Soil in Songdo Area, Incheon (인천 송도지역 준설토의 침강 및 압밀특성에 대한 실험 및 해석적 연구)

  • Lee, Chung-Won;Choi, Hangseok
    • Journal of the Korean GEO-environmental Society
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    • v.17 no.2
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    • pp.13-22
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    • 2016
  • Accurate settlement estimation of dredged soft soil deposits is significantly important to prevent potential disasters during land reclamation. An application of the non-linear finite strain consolidation theory is inevitable in dealing with a very soft ground formation such as dredged fill. In this paper, a series of the sedimentation-consolidation test, self-weight consolidation test and CRS test were conducted to clarify sedimentation and consolidation characteristics of dredged fill in the Songdo area, Incheon. In addition, the settlement of dredged fill was numerically simulated using the PSDDF program. The dredged soil obtained from the Songdo area was classified as low-compressible silt (ML) based on USCS (Unified Soil Classification System), and the final bulking factors were estimated to be 1.56 and 1.17 by Yano's method and the numerical simulation, respectively. This difference is attributable to relatively high reclaimed height and large permeability of dredged soil in this region.

The Analysis of the Painting Work Clothes Clothing Comfort and Wearer Mobility Considering the Work Environment in the Machine and Shipbuilding Industries

  • Park, Gin-Ah;Park, Hye-Won;Bae, Hyun-Sook
    • Journal of Fashion Business
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    • v.16 no.3
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    • pp.13-31
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    • 2012
  • The purpose of the study was to analyze the work clothes' clothing comfort and wearer mobility of painting workers with the consideration of the work environment features in the machine and shipbuilding industries in South Korea. A questionnaire survey was conducted for the study, which consisted of questions on the clothing comfort and wearer mobility aspects of painting work clothes by clothes types and body parts. The work clothes' clothing comfort and wearer mobility levels were scaled in 5 points i.e. 1(: very tight/very uncomfortable) to 5(: very slack/very comfortable). The painting work environmental hazardous features were considered as high impact levels of workplace temperature, oxygen deficiency, organic solvent, toxic gas factors while metal fragment factor only impacts 'low' in the painting processes with the findings throughout this study. Since the painting work consisted of surface washing and the spray and touch-up painting processes, which was carried out in an outdoor work place, the painting work clothes should meet high performance of waterproofing from the painting material and air permeability specially in summer as well as thermal performance in winter. The subjects painting workers' assessment of the existing work clothes' clothing oppression was in the levels between 3 (i.e. moderate) and 4 (i.e. comfortable) in a range of 1 to 5 points. The existing painting work clothes' wearer mobility was evaluated 'very uncomfortable' in all work clothes parts, especially, armhole length, biacromial breadth, sleeve length of the jumper; and body rise, waist, hip, thigh and knee circumferences of the pants.

Characterization of Shelf Life Extension Packaging Material for Food and Fresh Cut Agricultural Product: A Review (식품, 신선편이 농산물용 저장기간 연장 포장 소재 특성 및 평가)

  • Rhee, Jin-Kyu;Yu, Ji Ye;Kim, Mi-Kyung;You, Young-Sun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.22 no.3
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    • pp.119-125
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    • 2016
  • Fresh-cut agricultural products provide convenience to consumers. However, quality changes or microbial growth can easily occur due to physical changes such as cutting and peeling etc. during processing. Therefore, efforts have been made to develop a functional packaging for extension of shelf life of fresh-cut agricultural products, food etc., and researches on prolongation of storage period have been actively developed. The shelf life is extended by antimicrobial, far infrared rays, air permeability, anti-fogging, weak current, ethylene gas adsorption or decomposition, gas composition changes such as MA (Modified Atmosphere) or CA (Controlled Atmosphere). The method of extending the shelf life by various complex factors. This paper based on the published literature to extend the shelf life of fresh-cut agricultural products, food etc., The paper has summarized the storage period extension packing method, packaging material for shelf life extension and comprehensive evaluation method.

Study on the Soil Compaction (흙의 다짐에 관한 연구(I))

  • 강문묵
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.11 no.4
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    • pp.1783-1790
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    • 1969
  • It is one of the most economical method of soil stabilization works to compact soil, which increases soil density artificially. Compaction effort is to lessen void of soils, and consequently its aim is to enlarge friction and cohesion force, and reduce permeability of soil. Factors in compaction effort are moisture content, grain size, grain size distribution, physical properties, compaction method and temperature of soils etc. The results obtained in this study on the effects that grain size, gradation and physical properties influence upon compaction effort for 20 samples under the constant compaction method, are summarized as follows: 1. The bigger the maximum dry density is, the smaller the optimum moisture content is, on the other hand, the smaller the maximum dry densityis, the bigger the optimum moisture content is, ingeneral. 2. The coarser the grain size is, the bigger the maximum dry density is, and the optimum moisture content becomes small, and dry density-moisture content curve has the sharp peak, generally. Also, the finer the grain size is the smaller the maximum dry density is, and the optimum moisture content shows the big value, and dry density-moisture content curve has the dull peak. 3. The maximum dry density shows the biggest value on the sample to be about 15% of particles finer than No. 200 sieve. The more the percent passing of No. 10 sieve increase, the smaller the maximum dry density is. Soils which have uniformity coefficient less than 5 in particles larger than 0.074mm hardly show dry density-moisture content curve. 4. There is a relation which is ramax=2.3948-0.0376 Wopt between the maximum dry density and the optimum moisture content, namely, the maximum dry density is increased in proportion to decrease of the optimum moisture content. 5. There are relations to be the straight lines which the maximum dry density decrease, on the other hand, the optimum moisture content increase in accordance with enlargement of Atterberg Limit(LL, PL, PL) in compacted soils.

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Transdermal Delivery and Analgesic Effects of Lidocaine Hydrogel by Phonophoresis (초음파를 이용한 리도카인 수용성겔의 경피흡수 및 진통효과)

  • Yang, Jae-Heon;Kim, Dae-Keun;Song, Kyung-Suk;Yun, Mi-Young;Ahn, Hyo-Cho;Kim, Young-Il;Kim, Tae-Youl
    • Journal of Pharmaceutical Investigation
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    • v.37 no.3
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    • pp.149-158
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    • 2007
  • To investigate the permeability of lidocaine, percutaneous absorption studies were performed using excised hairless mouse skin and the penetration of lidocaine via the skin was determined. To increase the skin permeation of lidocine, the effects of $Labrasol^{(R)}$, $Labrafil^{(R)}$, $Labrafac^{(R)}$ and $Transcutol^{(R)}$ were investigated. The skin permeation of lidocaine was increased when $Labrasol^{(R)}$ and $Transcutol^{(R)}$ were used as permeation enhancer. To evaluate the influence of ultrasound, various factors such as application modes (continuous mode and pulsed mode), frequency (1.0 and 3.0 MHz) and intensity (1.0, 1.5 and 2.0 w/$cm^2$) were investigated with lidocaine hydrogel. The pronounced effect of ultrasound on the skin permeation of lidocaine was observed at all ultrasound energy levels. The influence of frequency having an effect on skin permeation rate was higher in the case of using 1 MHz, 2.0 w/$cm^2$ and continuous treatment. As the intensity of ultrasound increased, the permeation of lidocaine was accelerated. The in vivo anesthetic effects were evaluated by two aspects as mechanical threshold and electrical threshold. Six healthy volunteers consented to the randomized, double-blind, and cross-over designed study in each group. In each subject, 3 groups were adapted such as K group (ultrasound with gel base only), L group (lidocaine gel) and B group (ultrasound with lidocaine gel). In conclusion, lidocaine was potent anesthetic which could be block pain threshold effectively. And ultrasound could accelerate the skin penetration of lidocaine. The phonophoretic delivery system could be a good candidate for lidocaine as a local anaesthetic to improve the skin permeation and in vivo anaesthetic effect.