• Title/Summary/Keyword: Air- Permeability

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The Distribution Condition and Clothing Construction Factors of the Working Clothes - Reference to the Changwon National Industrial Complex -

  • Park, Gin-Ah;Park, Hye-Won
    • Journal of Fashion Business
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    • v.12 no.3
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    • pp.116-135
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    • 2008
  • To investigate the actual distribution condition and clothing construction factors of the working clothes supplied to the Changwon national industrial complex, 5 major companies in machinery, automotive, industrial engineering, shipbuilding and rolling stock in the industrial complex located in Gyeongsangnam-Do were selected. The questionnaire designed for the research consisted of working clothes distribution policies in manufacturing industry and the actual conditions of the design facts, repair and maintenance of the working clothes, etc. The analysis of the clothing construction factors of the working clothes provided by 5 respondent companies were conducted in parallel. The results derived from the study were as follows: The basic types of working clothes were the blouson jacket and straight pants; safety equipments for manufacture were safety helmets, gloves, snickers, goggles, masks, ear caps, wristlets, leggings, apron, etc. The size-charts adopted by the participant companies were the small-medium-large and cm/inch measurement size systems. To solve wearer's dissatisfaction with the garment fit, certain clothing construction factors were used, e.g. strap bands and the elastic band on a waist band. The types of fabrics used for the working clothes were mainly polyester/cotton and polyester/rayon blended ones. Moreover, to provide with more air permeability to wearers, the warp knit material was used to construct the lining and the armpit or back bodice slits. Lock, two-thread chain, safety, overedge stitches were applied with flat, lap felled, French, superimposed, lapped, bound and edge finishing seams to construct the working clothes selected.

An Experimental Study on the Fundamental Properties and Durability of Sewer Type Restorative Mortar Spread with Antibiotics (항균제를 도포한 하수시설용 단면복구 모르타르의 기초물성 및 내구특성에 관한 실험적 연구)

  • Kim, Moo-Han;Kim, Gyu-Yong;Kim, Jae-Hwan;Cho, Bong-Suk;Lee, Dong-Heck
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.3
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    • pp.195-202
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    • 2006
  • Deterioration of sewer concrete is representative that biochemical corrosion according to the $H_2S$ has growth by inhabit sulfur-oxidzing bacteria because of special environment in sewer. But in case of domestic, fundamentally, sulfur-oxidzing bacteria could moderate development of repair material method is need because of corrosion prevent method is inconsideration with carry out to improve project. In this paper, after development of spread type antibiotic with antibio-metal, antibacterial performance about sulfur-oxidzing bacteria of antibiotic and tested to estimate fundamental properties of bonding strength, abrasion contents, contents of water absorption, contents of air permeability, carbonation depth, chloride ion penetration depth and chemical resistance of spread with antibiotic restorative mortar.

In situ iron/manganese removal and permeability improvement at the river bank filtration site (강변여과수내 철망간 저감 및 투수성 개선)

  • Kim, Byung-Woo;Kim, Byung-Goon;Hur, Young-Teck;Kim, Dong-Sup;Kim, Hong-Suck
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.228-228
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    • 2018
  • 강변여과는 지하수 인공함양 방식 중 유도함양(induced recharge) 또는 간접함양 방식에 속한다. 이는 하천 및 강변 부근에 집수시설을 설치한 후, 미고결층 대수층(unconsolidated aquifer)의 자연 오염 저감능을 이용하여 지표수를 간접 취수하는 방식으로 수질이 불량한 지표수가 대수층을 관류하면서 희석, 화학적 이온 교환 및 반응, 흡착, 생물막(biofilm; 미생물에 의한 자연저감), 여과 등을 통하여 수질이 개선된다. 강변여과수내의 용존 농도가 높은 철과 망간은 수처리 비용증가, 용수관정 및 시설물의 수명단축을 초래한다. 따라서 강변여과 지역의 미고결 대수층에서 효과적인 철과 망간 동시 제거(vyredox)를 위해 에어서징(air surging)과 블록 서징(block surging)을 실시하기 위해서 실내 물탱크 모델(water tank model)에서 에어서징에 따른 공기 순환 우물시스템을 관찰하였으며, 이를 바탕으로 현장시험(Test bed)에 적용하였다. 미고결 대층수층에서의 철 망간은 음용수 기준치(각각 0.3 mg/L)를 초과하고 있으며, 강변여과 취수 개발 및 이용을 제한하는 요인이 되고 있다. 본 연구에서 사용된 에어서징과 블록서지 기술은 자갈층 및 미고결 대수층에 충진된 슬라임 및 폐색(clogging)을 제거함과 동시에 관정 주변의 대수층의 투수성 개선과 산화환경으로 치환되며, 대수층에 잔존하는 철/망간의 산화물들을 관정내로 빼낼 수 있는 방법이다. 따라서 서징에 따른 폐색 제거효율을 검토한 결과에서 철 망간 이온농도 저감효과와 관정 주변의 수리전도도(hydraulic conductivity) 및 저류계수(coefficient of storage)가 증가한 것으로 나타났다. 이와 같이 강변여과에 의한 폐색은 미고결층내 공기주입 및 블록서지를 통하여 철/망간 이온농도 저감 및 수리특성 개선 효과에 유용한 것으로 평가된다.

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Comparison of Physical Properties of Permeability Concrete Using Acrylic Polymer (아크릴 폴리머를 사용한 투수 콘크리트의 물성 비교 평가)

  • Hwang, Byoung-Il;Kim, Hyo-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.265-271
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    • 2019
  • The aim of this paper was to improve the shortcomings of Pitcher Concrete, a conventional ethylene-based polymer used in combination with the other components, and present basic data for use as improved road pavement material by applying an acrylic polymer. Existing ethylene polymer-based pitcher concrete materials were selected. Acrylic polymer was then added and the resulting mixture was evaluated. The compressive strength of the existing ethylene-based polymer pitcher concrete combination was low due to the large air gap, and a compressive strength of 24MPa was observed on the 28th day of road use, as defined by KS for an acrylic polymer-based pitcher concrete combination. Regarding the bending strength, the combined strength of the acrylic polymer-based pitcher concrete was excellent, and the factor of the pitcher was measured above the reference, 0.1(mm/s), in all variables. All parameters measured were less than 1%. The acrylic polymer mixing characteristics were able to maintain the dynamic modulus of elasticity for more than 120 cycles, but not more than 80 cycles for the other combinations. Therefore, the addition of more acrylic polymer than conventional ethylene polymer base is effective in improving the durability.

A Study on the Application of Medical Compression Arm Sleeves Using a MRT(Moisture Responded Transformable) Fibers (MRT(Moisture Responded Transformable)섬유의 의료용 압박소매 적용에 관한 연구)

  • Cho, Daehyun;Jung, Taedu;Park, Eunhee;Park, Youngmi
    • Textile Coloration and Finishing
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    • v.33 no.2
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    • pp.87-95
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    • 2021
  • In this study, the application of a medical compression sleeve of Moisture Responded Transformable(MRT) fibers to the treatment of lymphedema after surgery in breast cancer patients was investigated. MRT fibers were manufactured with PET and Nylon6 bi-component cross-section yarns, and compression sleeves of sleeves 1, 2, 3, and 4 were knitted in order of size, and then the physical properties and clinical tests were evaluated. As a result, the pressure of compression sleeve in wrinkle was the lowest in sleeve 1 with 3.81 kPa, and the highest in sleeve 4 with 5.22 kPa. Elastic recovery rate is that all parts except the top of the sleeve 1 exhibited 100%. The air permeability was good at 12.1 ~ 16.1 cm3/cm2/sec, and peeling was also comparatively excellent as grade 3. In addition, the weight of the compression sleeves 1, 2, and 3 decreased as 18.3 ~ 23.0 g/m2 depend on size, while the compared sample was heavier with 17.39 ~ 32.61 g/m2. In lymphoscintigraphy test, it was confirmed that the function of remaining lymph node was good in all patients. Although there were no differences between samples in skin irritation and tightness in wearing comfort, the manufactured sleeves showed better fit, lightness, fashion and breathability than the comparable sleeves.

A Study on Sound Absorption of Polyester Dry-laid Nonwovens (폴리에스터 건식부직포의 흡음성 연구)

  • Bae, Younghwan;Lee, Myungsung;Kim, Jung Yeon;Choi, Yeong Og;Yeo, Sang Young
    • Textile Coloration and Finishing
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    • v.34 no.1
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    • pp.38-45
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    • 2022
  • Sound absorbing materials are being developed in various materials and shapes and they are being applied in many fields such as construction, transportation, civil engineering, and sound. Among many sound-absorbing materials, polyester fiber has no environmental problems and harmfulness, and is a material with good sound absorption properties while being inexpensive. So it is manufactured as a nonwoven sound-absorbing material and used in various fields. In this study, polyester dry-laid nonwoven with different basis weight were manufactured using three types of polyester staple fibers: regular solid, single-hole hollow, and low linear density. We focused on the effects of the properties of the fibers, which constitute nonwovens, on the sound absorption properties, and we considered the basis weight. As the basis weight of the nonwoven fabric increased, the pore size became smaller and the air permeability was lowered, but the sound absorption coefficient was higher. However, the single-hole hollow polyester fiber did not contribute to the increase of the sound absorption coefficient of the nonwoven. It was established that, lower fiber fineness caused the sound absorption coefficient of the nonwoven to be increased. It was also found that the increase in the sound absorption coefficient due to the application of low fineness appeared from a certain basis weight or more.

Effectiveness study of a cement mortar coating based on dune sand on the carbonation of concrete

  • Korichi, Youssef;Merah, Ahmed;Khenfer, Med Mouldi;Krobba, Benharzallah
    • Advances in concrete construction
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    • v.13 no.4
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    • pp.315-325
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    • 2022
  • Reinforced concrete structures are exposed throughout their lifetime to the phenomenon of carbonation, which considerably influences their durability by causing corrosion of the reinforcements. The fight against this phenomenon is usually ensured by anti-carbonation coatings which have the possibility of limiting the permeability to carbon dioxide or with coatings which absorb the CO2 present in the air. A coating with good crack-bridging (sealing) capacity will prevent water from entering through existing cracks in concrete. Despite the beneficial effect of these coatings, their durability decreases considerably over time with temperature and humidity. In order to use coatings made from local materials, not presenting any danger, available in abundance in our country, very economical and easy to operate is the main objective of this work. This paper aim is to contribute to the formulation of a corrected dune sand-based mortar as an anti-carbonation coating for concrete. The results obtained show that the cement mortar based on dune sand formulated has a very satisfactory compressive strength, a very low water porosity compared to ordinary cement mortar and that this mortar allows an improvement in the protection of the concrete against the carbonation of 60% compared to ordinary cement mortar based on alluvial sand. Moreover, the formulated cement mortars based on dune sand have good adhesion to the concrete support, their adhesion strengths are greater than 1.5MPa recommended by the standards.

Development of a multi-functional companion animal cage design - Focusing on small companion dogs - (다기능 반려동물 이동장 디자인 개발- 소형 반려견을 중심으로 -)

  • Mi-Hwa Choi;Chanmi Lee;Nahyun Yoo;Hye-rim Yang
    • The Research Journal of the Costume Culture
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    • v.31 no.2
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    • pp.262-276
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    • 2023
  • This study aims to develop a multi-functional cage for dogs as a house to reduce their anxiety when they go out using cages. This study investigates the types and characteristics of cages and cage preference by surveying men and women in their 20s who use them. The cage product reviews are also analyzed. The research results are as follows: First, domestic dog cages are classified into crate, shoulder, cross (sling bag), backpack, carrier, and stroller types. The crate type is easy to clean and can be used as a house, but it is bulky and therefore inconvenient to carry when using public transportation. The shoulder type is a fabric material with good air permeability but has the disadvantage of being easily soiled. It can be used as a house and is light weight, making it convenient when using public transportation. Second, as a result of consumer research, respondents prefer the shoulder-type fabric over the crate-type plastic material. Third, from the shoulder-type product review, the shape stability, companion dogs' psychological safety, the wearability of companions, and management convenience are derived. Fourth, based on the survey results, a multi-functional cage is developed taking into account the companion dog, companion person, and functional factors.

Effect of Hysteresis on Soil-Water Characteristic Curve in Weathered Granite and Gneiss Soil Slopes during Rainfall Infiltration (풍화계열 사면의 불포화 함수특성곡선 이력이 강우 침투에 미치는 영향)

  • Shin, Gil-Ho;Park, Seong-Wan
    • Journal of the Korean Geotechnical Society
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    • v.22 no.7
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    • pp.55-64
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    • 2006
  • Shallow failures of slopes in weathered soils are caused by infiltration caused by prolonged rainfall. These failures are mainly triggered by the deepening of the wetting band accompanied by a decrease in suction induced by the water infiltration. In this paper, hysteresis on soil-water characteristic curve (SWCC) of granite and gneiss weathered soils is investigated using transient flow analysis respectively. Each case was subjected to artificial rainfall intensities and time duration depending on the laboratory-based drying and wetting processes. The results show that the unsaturated seepage on weathered slopes are very much affected by the initial suction of soils and unsaturated permeability of the soils. In addition, a granite weathered soil has a lower air-entry value, residual matric suction, and wetting front suction and less hysteresis loop than a gneiss weathered soil.

Effect of Coir Substrate Mixing Ratios on the Growth and Yield of Perilla Leaves under Hydroponics (수경재배 잎들깨의 생육과 수량에 미치는 코이어 배지의 혼합비율 효과)

  • Pyeong-Sic Park;Jong-Won Park;Hye-Kyeong Hyeon;Hyun-Sook Kim;Soo-Sang Hahm;Hak-Hun Kim;Hyo-Gil Choi
    • Journal of Environmental Science International
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    • v.33 no.1
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    • pp.17-25
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    • 2024
  • This study aimed to determine the most suitable coir substrate mixing ratio for optimizing the growth and yield of the "lpduelkkae 1" cultivar. We comprehensively analyzed the physicochemical properties, growth, and yields of four different substrate combinations: perlite (coir with mixing ratios of 70:30 (PC30), 50:50 (PC50), and 30:70 (PC70)) and 100% coir (C100). The results revealed substantial differences in substrate properties. C100 exhibited the highest total porosity and the lowest solid phase, indicating excellent air permeability. The pH levels and electrical conductivity (EC) values ranged from 5.4-6.8 and 1.2-3.1 dS·m-1, respectively. Leaf growth parameters, including length, width, and dry weight, showed positive correlations with high coir ratios, except for PC30. PC70 and C100 outperformed other substrates in stem growth, exhibiting superior stem diameter and fresh and dry weights. The quantity of marketable leaves was the highest in the C100 substrate. Furthermore, C100 comprised integrated levels of essential nutrients, such as Ca and Mg, owing to its high coir content. In conclusion, a coir ratio of approximately 70% (v/v) should be maintained in the substrate for creating an optimal cultivation environment. Furthermore, the selection of humidity-resistant varieties as well as precise nutrient and moisture management for different seasons and growth stages are crucial for a successful perilla leaf hydroponic cultivation.