• Title/Summary/Keyword: woven fabrics

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Preparation and Adsorption Properties of PA6/PSMA-OA Molecularly Imprinted Composite Membranes in Supercritical CO2

  • Zhang, Qing;Zhang, Xingyuan;Zhang, Wencheng;Pan, Jian;Liu, Ling;Zhang, Haitao;Zhao, Dong;Li, Zhi
    • Bulletin of the Korean Chemical Society
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    • v.32 no.9
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    • pp.3348-3354
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    • 2011
  • Oleanolic acid (OA) as template molecule, polyamide-6 (PA6) as basement membrane and poly(styrene-comaleic acid) (PSMA) were used to prepare PA6/PSMA-OA molecularly imprinted composite membranes by phase inversion method in supercritical $CO_2$ ($ScCO_2$). The template molecule (OA), [poly(styrene-co-maleic anhydride) (PSMAH), PSMA, molecularly imprinted membranes (MIMs) imprinting OA and MIMs after elution were all characterized by Fourier transform infrared spectroscopy (FTIR). The conditions that were the mass ratio between PSMA and OA from 3:1 to 8:1, temperature of $ScCO_2$ from $35^{\circ}C$ to $50^{\circ}C$ and pressure of $ScCO_2$ 12 MPa to 17 MPa were studied. It was obtained the largest adsorption rate and purity of OA after adsorption of the resultant MIMs, 50.41% and 96.15% respectively. After using PA6 film and non-woven fabrics as basement membrane respectively, it was found that smaller aperture of PA6 was used as basement membrane, a higher adsorption rate and a higher purity of OA after adsorption of the MIMs were obtained, and so were the stability and reproducibility of the resultant MIMs. After template molecules being removed, the MIMs had effective selectivity hydrogen bonding to separately bind in the binary components to the template molecules-oleanolic acid.

Evaluation of Thermal Insulation Properties of Covering Materials to Protect Peach Trunks against Freezing Injury (복숭아 주간부 동해 예방을 위한 피복재의 보온성 평가)

  • Shin, Hyunsuk;Yun, Seok Kyu;Choi, In Myung;Kim, Sung Jong;Yun, Ik Koo;Nam, Eun Young;Kwon, Jung Hyun
    • Journal of Bio-Environment Control
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    • v.25 no.4
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    • pp.288-293
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    • 2016
  • The study was performed to evaluate thermal insulation covering materials (TICMs) to protect peach trunks against freezing temperatures in winter season by investigating thermo-physical properties and practical thermal insulation effect of the TICMs which was made of white non-woven fabrics, yellow paper sheets, and waterproof fabric pads. Among the three TICMs, Waterproof fabric pad (double layer) possessed the best performance about thermal insulation rate and thermal resistance among three kinds of TICMs. Day thermal insulation effects of waterproof fabric pad, which prevent from temperature rise on the bark tissues of trunks during the day time, were $14.09^{\circ}C$. Night thermal insulation effects of them, which prevent from temperature decline on the bark tissues of trunks at night time, were $7.23^{\circ}C$. Waterproof fabric pad showed the highest day and night thermal insulation effects. Thus our results suggest that development of TICMs using waterproof fabric pad might be helpful to protect the bark tissues of trunks from freezing injury.

Regional Analysis of Forest Eire Occurrence Factors in Kangwon Province (강원도 지역 산불발생인자의 지역별 유형화)

  • 이시영;한상열;안상현;오정수;조명희;김명수
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.3 no.3
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    • pp.135-142
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    • 2001
  • This study attempts to categorizes the factors of forest fire occurrences based on regional meteorologic data and general forest no characteristics of 18 cities and guns in Kangwon province. lo accomplish this goal, some statistical analyses such as analysis of variance, correspondence analysis and multidimensional scaling were adopted. To reveal the forest fires pattern of study region, a categorization process was conducted by employing the quantification approach which modified and quantified the metric-data of fire occurrence dates. Also, The fire occurrence similarity was compared by using multidimensional scaling for each study region. The major results are summarized as follows: It was found that the meteorological factors emerged as different to each region are average and maximum temperature, minimum dew point temperature and average and maximum wind speed. In the result of correspondence analysis representing relationships between fire causes and study regions, Kangrung is caused by arsonist, Chulwon, Hwachen and Yanggu caused by military factor, Sokcho and Chunchen caused by the debris burning, and Samchuk caused by general man-caused fires, respectively. Finally, the forest fire occurrence pattern of this study regions were divided into five areas such as, group I including Samchuk, Kangryung, Chunchen, Wonju, Hongchen and Hhoingsung, group II including Donghae, Taebaek, Yangyang and Pyongchang, group III including Jungsun, Chulwon and Whachen, group Ⅵ including Gosung, Injae and Yanggu, and group V including Shokcho and Youngwol.

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A Study on the Reproduction Experimental of Breaking of dried stalks technique of Recorded in Oju-Yeonmunjang jeon-Sango in the late Joseon Dynasty (조선 후기 『오주연문장전산고』에 기록된 자연건조쇄경식 제섬 기술 재현 실험 연구)

  • Kong, Sanghui;Ree, Jiwon;Kim, Hajin
    • Korean Journal of Heritage: History & Science
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    • v.52 no.4
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    • pp.170-183
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    • 2019
  • Fiber scutching refers to the process of extracting fibers from plants by separating or extracting fibers from the raw materials. As the definition of the term implies, the "Fiber Scutching" is performed on plants with advanced bast fiber as the primary material processing technique performed on plant materials. Some of the most popular phosphorus plants are ramie, hemp, flax, and the paper mulberry, which have a long history of cultivation and a wide range of distribution, making them very universal as a material supporting human life and culture. This study was described in Oju-yeonmunjangjeon-sango but was designed to re-examine the method of breaking dried stalks, which is currently unused in Korea, to examine the feasibility and characteristics of the technology. As a result of sampling and experimenting with hemp bast using the method recorded in the literature, hemp fiber was actually produced. The criteria for removing the shell from the hemp stem were the degree of discoloration and drying, and only when the stalk was completely discolored to yellow could segregation of the stalk from the shell be performed. The amount of sunlight and temperature were conditions that accelerated drying. However, if exposed for a long time, it is confirmed that hemp bast will be in a suitable condition to process, regardless of the amount of sunlight and temperature. 'Breaking of dried stalks', which utilizes the physical power of 'threshing with a flail' is considered a core process of the fiber scutching technique in 'Yukjin' in Hamgyeong-do. The bark and the core of the hemp were separated by tapping, the bast was thinly split, and the shell was peeled off, making it suitable for collecting with thread. The method of collecting the fibers by applying physical power causes downing on the fibers, which is to be generally avoided in the manufacture of bast fabric woven hemp or ramie. However, Hamgyeong-do's fiber scutching method seems to have applied this principle to the method of making fragile fabrics by using it in reverse. This method is distinct from the steaming or boiling of the stalks' in Andong, Korea, and it is similar to the Western method of spinning fabrics.

Hydrophilic Modification of Porous Polyvinylidene Fluoride Membrane by Pre-irradiating Electron Beam (전자빔 전조사를 이용한 Polyvinylidene Fluoride 다공막의 친수화 개질)

  • Choi, Yong-Jin;Lee, Sung-Won;Seo, Bong-Kuk;Kim, Min
    • Membrane Journal
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    • v.21 no.2
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    • pp.118-126
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    • 2011
  • A method of light pre-irradiation, one of methods modifying hydrophobic surface to hydrophilic surface in a membrane, was proposed to overcome the drawback of previous methods such as blending, chemical treatment and post-irradiation, Process of membrane preparation in the study was comprised of 4 parts as follows: firstly process of precursor preparation to introduce hydrophilic nature under atmosphere and aqueous vapor by irradiating electron beam (EB), secondly process of dope solution preparation to cast on non-woven fabrics, thirdly process of casting to prepare membrane and finally process of coagulation in non-solvent to form porous structure. The merit of this method might show simple process as well as homogenous modification compared to previous methods. To carry it out, precursor was prepared by irradiating EB to powder PVDF at 75~125 K Gray dose. Precursor prepared was analyzed by FTIR, EDS and DSC to confirm the introduction of hydrophilic function and its mechanism. From their results, it was inferred I conformed that hydrophilic function was hydroxy1 and it was introduced by dehydrozenation. Hydrophilicity of membranes prepared was evaluated by contact angle (pristine PVDF : $62^{\circ}$, 125 K Gray-PVDF$13^{\circ}$). Porosity was evaluated by mercury intrusion method, simultaneously morpholoy and surface pore size were observed by SEM phothographs. The result showed the trend that more dose of EB led to smaller pore size and to lower porosity (pristine PVDF : 82%, 125 K Gray-PVDF : 63%). Trend of water permeability was similar to result above (pristine PVDF : 892 LMH, 125 K Gray-PVDF : 355 LMH).

A Study on the Meaning and Types of Banpo [斑布] during the Joseon Dynasty (조선시대 반포(斑布)의 의미와 형식 연구)

  • Ree, Jiwon
    • Korean Journal of Heritage: History & Science
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    • v.53 no.3
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    • pp.164-183
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    • 2020
  • In the textile culture of the Joseon Dynasty, the historic record of Banpo is fragmentary and contains many missing details. The main reason is a lack of associated literature, and it is also significant that the actual substance used is not clear at present. Banpo is a kind of cotton, but this has not been confirmed in the traditional textiles that are currently handed down. The word Ban [斑] in Banpo means "stain", and the letter Po [布] means "fabric". At the border of white discourse, Banpo did not receive attention as a research topic. This study is an attempt to restore some of the textile culture of the Joseon Dynasty through Banpo. Banpo is not just limited to the Joseon Dynasty; it is an important material for examining the development of textile culture and exchange in East Asia. This study was broadly divided into three parts. First, the record and meaning of Banpo during the Joseon Dynasty were examined. Records of Banpo can be seen from the early Joseon period during King Sejo and Seongjong, and the production and actual use of Banpo have been confirmed. Banpo was maintained until the beginning of the 20th century, but is no longer observed. Banpo is a woven fabric made of cotton yarn dyed in many colors and has appeared in Southeast Asia since ancient times. In East Asia, there are other fabrics similar to Banpo, such as Ho [縞], Sum [纖], and Chim [綅]. In particular, the correlation between Banpo and Ho is an important link in understanding Banpo in the Joseon Dynasty. Second, the meaning of Banpo was examined from various angles through comprehensive analysis of Chinese and Japanese literature records and cases. The appearance and development of Banpo moved in sync with the period when cotton was introduced into East Asia. In East Asia, cotton was introduced and produced in earnest from the end of the Song Dynasty to the beginning of the Yuan Dynasty, and the meaning of Banpo was diversified. In China, the name of Banpo was changed to Hwapo [花布], Gizapo [碁子布], Gizahwapo [棋子花布], etc. Japan was late to introduce cotton and developed it in acceptance of the changed meaning. In Japan, use of the name Banpo is not on record, but a Ryujo [柳條] fabric of the same type as banpo has been identified. This Ryujo is the same concept as Ho and Hwapo, and later merged into Ho. Names such as Ho, Hwapo, Banpo, etc. were used differently in each country, but the form was shared across East Asia. Third, based on the meaning of Banpo shared in East Asia, the format of Banpo in the Joseon Dynasty was classified. The format of Banpo in the Joseon Dynasty can be divided into grid and striped versions. The name Banpo disappeared over time, but the form remained and was passed down until recently. I hope that this study will help restore Banpo in the future.

Comparison of Thermal Insulation of Multi-Layer Thermal Screens for Greenhouse: Results of Hot-Box Test (온실용 다겹보온자재의 보온성 비교 -Hot box 시험 결과를 중심으로-)

  • Yun, Sung-Wook;Lee, Si-Young;Kang, Dong-Hyeon;Son, Jinkwan;Park, Min-Jung;Kim, Hee-Tae;Choi, Duk-Kyu
    • Journal of Bio-Environment Control
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    • v.28 no.3
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    • pp.255-264
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    • 2019
  • In this study, we conducted the hot box tests to compare the changes in thermal insulation for the four types of multi-layer thermal screens by the used period after collecting them from the greenhouses in the field when they were replaced at the end of their usage. The main materials for these four types of multi-layer thermal screens were matt georgette, non-woven fabrics, polyethylene (PE) foam, chemical cotton, etc. These materials were differently combined for each multi-layer thermal screen. We built specimens ($70{\times}70cm$) for each of these multi-layer thermal screens and measured the temperature descending rate, heat transmission coefficient, and thermal resistance for each specimen through the hot box tests. With regard to the material combinations of multi-layer thermal screens, thermal insulation can be increased by applying a multi-layered PE foam. However, it is considered that the multi-layered PE foam significantly less contributes to heat-retaining than chemical wool that forms an air-insulating layer inside multi-layer thermal screens. For the suitable heat-retaining performance of multi-layer thermal screens, basically, materials with the function of forming an air-insulating layer such as chemical cotton should be contained in multi-layer thermal screens. The temperature descending rate, heat transmission coefficient, and thermal resistance of multi-layer thermal screens were appropriately measured through the hot box tests designed in this study. However, in this study, we took into consideration only the four kinds of multi-layer thermal screens due to difficulties in collecting used multi-layer thermal screens. This is the results obtained with relatively few examples and it is the limit of this study. In the future, more cases should be investigated and supplemented through related research.