• Title/Summary/Keyword: natural barrier

Search Result 286, Processing Time 0.031 seconds

Greenhouse Test Results for Two Years of Sheet shaped Root Barrier Materials Apply to Green Roof System for Sustainable Building Construction

  • Jang, Dae-Hee;Kim, Hyeon-Soo;Choi, Soo-Kyung
    • Journal of the Korea Institute of Building Construction
    • /
    • v.11 no.6
    • /
    • pp.634-644
    • /
    • 2011
  • Recently, As a part of urban forestation, the introductions of green roofs into public projects has been actively driven. Supported by this policy, the sizes of domestic green roof related markets have been rapidly expanding and many types of root barrier materials developed in Korea or abroad are being commercially distributed. In this study, root barrier tests were conducted over two years with nine types of sheet type waterproof materials that are the most commonly used as root barrier layers in green roof systems. The test conditions prepared considered the climates, natural features and vegetation in Korea and the results and related root barrier performance were verified. From the results of this study, the necessity to improve the joint part of root barrier sheets and forming methods has been identified and a measure to improve domestic root barrier testing methods was proposed.

A Study on Thermal Load Management in a Deep Geological Repository for Efficient Disposal of High Level Radioactive Waste

  • Jongyoul Lee;Heuijoo Choi;Dongkeun Cho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.20 no.4
    • /
    • pp.469-488
    • /
    • 2022
  • Technology for high-level-waste disposal employing a multibarrier concept using engineered and natural barrier in stable bedrock at 300-1,000 m depth is being commercialized as a safe, long-term isolation method for high-level waste, including spent nuclear fuel. Managing heat generated from waste is important for improving disposal efficiency; thus, research on efficient heat management is required. In this study, thermal management methods to maximize disposal efficiency in terms of the disposal area required were developed. They efficiently use the land in an environment, such as Korea, where the land area is small and the amount of waste is large. The thermal effects of engineered barriers and natural barriers in a high-level waste disposal repository were analyzed. The research status of thermal management for the main bedrocks of the repository, such as crystalline, clay, salt, and other rocks, were reviewed. Based on a characteristics analysis of various heat management approaches, the spent nuclear fuel cooling time, buffer bentonite thermal conductivity, and disposal container size were chosen as efficient heat management methods applicable in Korea. For each method, thermal analyses of the disposal repository were performed. Based on the results, the disposal efficiency was evaluated preliminarily. Necessary future research is suggested.

The Antecedents Of Brand Love Toward Natural Products: An Approach of S.O.R Theory

  • NGUYEN, Le Thai Hoa;NGUYEN, Hoang Anh
    • Asian Journal of Business Environment
    • /
    • v.12 no.2
    • /
    • pp.13-28
    • /
    • 2022
  • Purpose: Natural products are becoming gradually popular because of their health - related benefits and consumers' environmental awareness. However, research in this field remains limited, the present study attempts to address this research gap by measuring the influencing levels of the antecedents on natural product brand love. Research design, data and methodology: The study employs S-O-R (Stimulus - Organism - Response) framework together with Innovation Resistance Theory and Dual-Factor Theory to propose the research model, in which health and environmental stimuli influence both of facilitators and inhibitors of internal states or organism, and then shape purchase intention and brand love as consumers' responses. The mixed research method is designed with the application of structural equation model (SEM) to analyze 530 consumers collected by convenience sampling. Results: The results revealed that two chosen stimuli, including health awareness and environmental concern were positively related to both facilitators (natural content and regional products) and inhibitors (image barrier and usage barrier) and these four factors were significantly associated to purchase intention and brand love. Furthermore, purchase intention played the mediating role on the relationship between the four organisms and brand love. Conclusions: The originality of this paper is extend S-O-R theory into natural product context with mediating effects in an emerging economy. The findings make theoretical contribution on consumer behavior and managerial implication.

Estimation of Fatigue Characteristics Using Weibull Statistical Analysis with Aramid Fiber on LNGC Secondary Barrier (LNGC 2차 방벽에 적용된 Aramid 섬유의 Weibull 통계 분석을 이용한 피로특성 평가)

  • Park, Jin Hyeong;Oh, Dong Jin;Kim, Min Gyu;Kim, Myung Hyun
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.54 no.5
    • /
    • pp.415-420
    • /
    • 2017
  • Insulation systems in Liquefied Natural Gas Carriers (LNGC) are vulnerable to sloshing impact and fatigue loads because of waves. If gas leaks into the primary barrier, the Flexible Secondary Barrier (FSB) prevents the leakage of gas in this system. Fatigue strength of the FSB largely depends on the behavior of composite materials. In this study, a new system is applied to the FSB using aramid fiber to improve the fatigue strength of the secondary barrier, with the intention of replacing conventional E-glass fibers. The manufacturing method involved varying the ratio of the aramid fiber to the E-glass fiber for optimum design of the FSB. The fatigue tests results of the secondary barrier using aramid fiber were superior to that using E-glass fiber. The statistical analysis is performed to obtain the fatigue test results and estimate the probability of failure as well as the design guideline of LNGC secondary barriers.

Improvement of skin barrier function using lipid mixture

  • Park, Won-Seok;Son, Eui-Dong;Nam, Gae-Won;Park, Jong-Ho
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.27 no.1
    • /
    • pp.53-72
    • /
    • 2001
  • Dry skin is caused mainly by the perturbation of stratum corneum lipids which affected by ageing, change of season, excess use of surfactant and the effect of disease like atopic dermatitis and psoriasis. Intercellular lipid structures in stratum corneum are responsible for the barrier function of mammalian skin. The major lipd classes that can be extracted from stratum corneum are ceramides, cholesterol and fatty acid, which make up approximately 50, 25, 10 percent of the stratum corneum lipid mass, respectively. Small amount of cholesterol sulfate, phospholipids, glycosylceramide and cholesterol esters are also present. Recent studies have shown that application of one or two these lipids to the perturbed skin delays barrier recovery; only equimolar mixtures allow normal recovery. We observed that barrier recovery rate was improved in hairless mouse by topical application of single neutral lipids (ceramide, free fatty acid, cholesterol) and lipid mixtures. Whereas the application of single lipid didn’t allows a significant enhancement comparing with normal barrier repair, the equimolar mixtures of 3 components(including synthetic pseudoceramide PC104) improved barrier repair, as assessed by the transepidermal water loss. At clinical study to the volunteers aged over sixty, skin dryness recuperated by the increase of moisture(capacitance) and the reduction of scaling. Utilization of physiologic lipid mixture containing natural ceramides or synthetic pseudoceramide could lead to new forms of topical therapy for the dryness and dermatoses(e.g., psoriasis, atopic dermatitis and irritant dermatitis).

  • PDF

Applicability Evaluation of Tetrapod Debris Barrier -A Case of Honggyeri Area in Sanchung County- (테트라포드 사방댐의 적용성 평가 -산청군 홍계리 지역을 대상으로-)

  • Kim, Ki Heung;Park, Jae Hyeon;Ma, Ho Seop
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.15 no.1
    • /
    • pp.119-132
    • /
    • 2012
  • In order to connect eco-corridor and to harmonize with natural environment, it is necessary to construct small debris barrier. Therefore, we will evaluate applicability of small debris barrier which made of tetrapod utilized in construction of seashore protection facilities and breakwater. From result compared with the adaptation processes in fields, tetrapod were stabilized to critical tractive force. Stability evaluation method on sliding and overturn of tetrapod debris barrier was developed, and hereafter could be applied to similar debris barriers. According to results analyzed to continuity on sediment supply in debris barrier, boulders were deposited in upstream and gravels were deposited in downstream. Therefore, tetrapod debris barrier will be able to prevent in the long-term the erosion of river bed in down-stream, and the maintenance is easy because dredging is not necessary. Current were formed in between the tetrapod provided eco-corridors for fishes and shellfishes.

Vehicle-induced aerodynamic loads on highway sound barriers part1: field experiment

  • Wang, Dalei;Wang, Benjin;Chen, Airong
    • Wind and Structures
    • /
    • v.17 no.4
    • /
    • pp.435-449
    • /
    • 2013
  • The vehicle-induced aerodynamic loads bring vibrations to some of the highway sound barriers, for they are designed in consideration of natural wind loads only. A field experiment is carried out with respect to three important factors: vehicle type, vehicle speed and the vehicle-barrier separation distance. Based on the results, the time-history of pressures is given, showing identical characteristics in all cases. Therefore, the vehicle-induced aerodynamic loads acting on the highway sound barrier are summarized as the combination of "head impact" and "wake impact". The head impact appears to have potential features, while the wake impact is influenced by the rotational flow. Then parameters in the experiment are analyzed, showing that the head impact varies with vehicle speed, vehicle-barrier separation distance, vehicle shape and cross-sectional area, while the wake impact is mainly about vehicle-barrier separation distance and vehicle length.

Anti-oxidative and skin barrier effects of natural plants with a supercritical extract (초임계 추출을 적용한 식물추출물의 항산화 및 피부장벽 효과)

  • Kim, Bora;Lee, Su Min;Hwang, Tae-Young;Kim, Hyun-Soo
    • Food Science and Preservation
    • /
    • v.20 no.5
    • /
    • pp.597-601
    • /
    • 2013
  • In this study, we searched for bioactive compounds from natural resources with a supercritical extract. We selected the extracts of Chrysanthemum zawadskii, Lufa cylindrica, Paeonia lactiflora, Gardenia jasminoides and Scutellaria baicalensis, as natural materials, and evaluated the effects of their skin barrier function. We found that these extracts increased the transactivation activity of the PPAR-responsive element (PPRE) and the anti-oxidation with different priorities, respectively. In addition, these extracts promoted the expression of proteins related to cornified envelope (CE) formation, such as involucrin. From these results, we suggest that natural materials from supercritical extracts will be pertinent candidates for the improvement of the epidermal permeability barrier function.

Examination Conditions of Root Barrier for Green Roof System and Result of Intermediate Observation of Three Months against Representative Root Barrier (옥상녹화용 방근층의 방근성 시험조건 설정 및 주요 방근소재에 대한 3개월간의 중간관찰 결과)

  • Shin, Yun-Ho;Jang, Dae-Hee;Kim, Hyun-Soo;Choi, Soo-Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2008.11a
    • /
    • pp.245-249
    • /
    • 2008
  • The purpose of this study is to test performances of 14 types of root barrier materials by applying testing plants and soils suitable for weather and natural features of Korea. For testing plants, Plioblastus pygmaed Mitford A. and Pyracantha angustifolia have been selected. For testing soil, mixture of pearlite and peat moss in 3:1 ratio(volume). Testing container has been fabricated with duplicated structure having inner and outer containers. And the outer container has 2 hinges on its side wall to allow opening and closing. Wet rock wool with 50mm in thickness has been inserted between inner and outer containers to allow root to penetrate through root barrier material and continue to grow. We planted 12 Plioblastus pygmaed Mitford A. and 4 Pyracantha angustifolia per one testing container. Three testing samples have been made for 1 type of root barrier material, which become a total 42 specimens. Planted testing samples have been installed within the greenhouse, which will be observed regularly for 2 years from now on. We started test from July 11, 2008 and had performed intermediate observations every month for initial 3 months. From the 3rd intermediate observation on Sept. 18, we confirmed that 6 types of root barrier materials have penetrated roots. Even though two types of them(EDPM Sheet, Polyethylene Sheet) have been generally used as root barrier materials for roof planting system, all of three testing samples have a lot of penetrated roots. This result proves that it is not reasonable to introduce testing methods of root barrier from Europe or Japan.

  • PDF