• Title/Summary/Keyword: Fiber Degradation

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A Study on National Fashion Cases of Conscious Fashion as an ESG Practice (ESG 실천 방안으로서의 컨셔스 패션(Conscious Fashion)의 국내 패션 사례 연구)

  • Heejeong Park
    • Journal of Fashion Business
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    • v.27 no.5
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    • pp.13-25
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    • 2023
  • The implementation of ESG practices in the fashion industry has been accelerating, and its significance has been growing across all industries. This paper aims to examine the strategies for ESG implementation in domestic fashion brands and analyze how ESG principles are applied in the context of domestic conscious fashion. To analyze conscious fashion as a means of ESG implementation, the evaluation criteria of ESG from the Textile Fashion Policy Research Institute were utilized as analytical tools. As a result, five categories of domestic conscious fashion emerged: animal-free vegan fashion, eco-friendly plant-based vegan materials, upcycled fashion, regenerated fiber fashion utilizing waste materials, and fair trade fashion. The characteristics of these ESG practices in conscious fashion were identified with four key features. Firstly, the adoption of environmentally friendly materials demonstrates a tendency towards resource conservation, minimizing environmental degradation, and protecting ecosystems. Secondly, technology-driven circular practices are predominant in vegan and upcycled types, evident in the development of fashion materials and secondhand content. Thirdly, design practices based on scarcity incorporate characteristics of upcycling and fair trade. Lastly, the practices of social and ethical values underlie the philosophies of three types of conscious fashion. With the acceleration of ESG practices in the fashion industry and the increasing importance thereof, it is expected that domestic conscious fashion in South Korea will diversify in the future.

Structural Capacity Evaluation of High Strength Concrete Short Columns with Various Design Parameters under High Temperatures (고온하에서 다양한 설계변수에 따른 고강도 콘크리트 단주의 구조 성능 평가)

  • Kim, Hee-Sun;Mun, Ji-Young;Park, Jee-Eun;Shin, Yeong-Soo
    • Journal of the Korea Concrete Institute
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    • v.23 no.5
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    • pp.637-645
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    • 2011
  • It is well known that high strength concrete with compressive strength higher than 50 MPa shows severe material and structural damages under fire due to spalling. To understand degradation of structural capacity of fire damaged high strength concrete structures, not only thermo-mechanical behavior needs to be defined, but also structural behavior of high strength concrete member under high temperature needs to be investigated. In this study, structural tests are performed by applying axial loads on high strength concrete columns exposed at elevated temperatures for assigned amount of time. The tested columns are prepared to have different concrete strength and polypropylene fiber percentage. The test results show that structural capacity of the columns decreased with increased compressive strength of concrete under same heating condition. Especially, it is interesting to note that high strength concrete columns with polypropylene fiber for spalling proof did not improve structural capacity compared to the columns without polypropylene fiber. The findings from the test are able to improve fire proof design of high strength concrete structural members and predicting structural performance of fire damaged structural members.

Improvement method for viscosity measurement of high viscosity paper and fabric cultural heritages (고점도 지류 및 섬유 문화재의 점도 측정 개선 방법 연구)

  • Kim, Young-Hee;Hong, Jin-Young;Jo, Chang-Wook;Kim, Soo Ji;Lee, Jeung-Min;Seo, Min Seok;Choi, Kyoung Hwa
    • 보존과학연구
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    • s.34
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    • pp.20-29
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    • 2013
  • Paper, textile and wood materials are mainly consisted of cellulose. Cellulose is high molecule and make up the strong crystalline structure by hydrogen bonds. In particular, the polymerization degree of cellulose are closely related to the strength of fiber, and the permanence. the useful life of fiber, also depends on the degradation of this substance. The viscosity of cellulose is considered to be an important indicator of fiber damage in high molecule polymers. The viscosity measurements with CED solution is used to measure the molecular weight and the degree of polymerization of cellulose. Cellulose viscosity of wood fibers is measured with TAPPI standard method T230. However, TAPPI standard method T230 is difficult to completely dissolving the cellulose of high molecular weight and large degree of polymerization, such as Korea traditional papers and fabrics made with mulberry, ramie, cotton fibers. In this study, The high viscosity of hanji and fabric was measured with TAPPI standard method T254. T254 method is that the cellulose specimen with the proper amount of weaker (0.167M CED) solution, and completely dissolved with the stronger (1.0M CED) solution. It was found that cellulose with high degree of polymerization was dissolved more easily in general CED method.

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Study on Physical Properties of Maleic anhydride Grafted Polypropylene (PP)/Kenaf Fiber (KF) Composites (말레인산 무수물 그래프트 폴리프로필렌/케나프 섬유 복합체의 물성에 대한 연구)

  • Ku, Sun Gyo;Kim, Yu Shin;Hong, Young Eun;Kim, Dong Won;Kim, Ki Sung;Kim, Youn Cheol
    • Applied Chemistry for Engineering
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    • v.28 no.1
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    • pp.73-79
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    • 2017
  • Maleic anhydride (MAH) grafted polypropylene (PP-g-MAH) copolymers were prepared by changing MAH and styrene monomer (SM) content, using a twin screw extruder at $190^{\circ}C$. The grafting degree was measured by non-aqueous back titration method. The grafting degree of PP-g-MAH-SM copolymer was higher than that of PP-g-MAH at the same MAH content. PP-g-MAH-SM/kenaf fiber (KF) composites were also prepared by using a PP-g-MAH as a matrix at $200^{\circ}C$ and the KF content was fixed at 20 wt%. Based on the degradation temperature investigated by TGA, the thermal stability of PP-g-MAH-SM/KF composites was more enhanced than that of PP-g-MAH only. Mechanical properties of the composites were also improved when MAH and SM applied together. The adhesion degree between the copolymer and KF was confirmed by both SEM pictures of the fractured surface and contact angles.

Flexural Behaviors of GFRP Rebars Reinforced Concrete Beam under Accelerated Aging Environments (GFRP Rebar 보강 콘크리트 보의 급속노화환경에서의 휨 거동에 관한 연구)

  • Park, Yeon-Ho;Choi, Yeol
    • Journal of the Korea Concrete Institute
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    • v.25 no.2
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    • pp.137-144
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    • 2013
  • The use of fiber-reinforced polymer (FRP) reinforcing bars in concrete structures has been increased as an alternative of steel reinforcement which has shown greater vulnerability to corrosion problem. However, the long-term performance of concrete members with FRP reinforcement is still questioned in comparison to the used of steel reinforcement. This study presents the results of an experimental study on the long-term behaviors of GFRP (glass fiber reinforced polymer) bar reinforced concrete beams after exposed to accelerated aging in an environmental chamber with temperature of $46^{\circ}C$ ($115^{\circ}F$) and 80% of relative humidity up to 300 days. The objectives of this research was to compare strength degradation and change of ductility between GFRP reinforced concrete beams and steel reinforcement beams after accelerated aging. Two types (wrapped and sand-coated surface) of GFRP bars and steel were reinforced. in concrete beams. Test results show that the failure modes of GFRP bar reinforced concrete beams are very similar with traditional RC beams, and the change of load-carrying capacity of steel reinforcing concrete beam is greater than that of GFRP bar reinforcing concrete beam under the accelerated aging. Test result also shows that the use of GFRP reinforcing in concrete could be introduced more brittle failure than that of steel reinforcing for practical application. The deformability factor up to compression failures indicates no significant variation before and after exposure of accelerated aging.

Effects of Mixing Time for Total Mixed Rations using Corn Silage on Ruminal In situ Dry Matter Degradation and Milk Production in Dairy Cows (옥수수 사일리지 이용 섬유질배합사료의 배합시간에 따른 In situ 반추위 분해율 및 착유우의 산유특성에 미치는 영향)

  • Lim, Dong-Hyun;Ki, Kwang-Seok;Choi, Sun-Ho;Kim, Tae-Il;Park, Seong-Min;Park, Su-Bum;Kwon, Eung-Gi;Kim, Eun-Tae
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.34 no.4
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    • pp.288-295
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    • 2014
  • This study was conducted to evaluate the effect of mixing time for TMR (total mixed rations) mixed with corn silage on particle size, peNDF (physically effective neutral detergent fiber), laceration, and ruminal in situ dry matter degradation. The study also aimed to evaluate the effect of consumption of the TMR on the milk yield and milk components of mid-lactational dairy cows. TMRs were mixed for 30 minutes (T1) and 50 minutes (T2) using the same material. All samples were then analyzed with a Penn State Particle Size Separator (PSPS). The particle size of T1 was significantly lower in the bottom pan (8 mm>) than that of T2 (p<0.01). $peNDF_{&gt;8.0}$ was significantly higher in T1 (17.18%) than in T2 (13.85%) (p<0.01). For ruminal in situ dry matter degradation of particle retention (>19 mm), no significant difference was found after 72 hours incubation, although T1 degradation was significantly higher after 24 hours incubation (p<0.01). Milk yield was no different between the groups of cows, whereas the milk fat from T1 fed cows was significantly higher (p<0.01). The results show that feeding TMR mixed for 30 minutes to dairy cows may improve the physical value of forage without negative effects on the milk yield and milk components.

Signal Analysis of Optical Biosensor to Detect Peroxide Using Electrically Controlled Release System (전기적 방출 조절 시스템을 이용한 광 페록사이드센서의 개발)

  • Min, Jun-Hong;Lim, In-Hee;Kim, Hyo-Han;Lee, Sang-Beak;Choi, Jeong-Woo;Lee, Won-Hong
    • Journal of Sensor Science and Technology
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    • v.6 no.1
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    • pp.35-42
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    • 1997
  • The optical biosensor using the electrically controlled release of reactive reagent is developed for the detection of peroxide. Rapid degradation of polymer complex of PEOx and PMAA occurs as the applied current increases and thus released amount of HPA increases. The degradation velocity of polymer and the amount of HPA released are linearly proportional to the applied current. Peroxide is reacted with the released reagent by peroxidase and then the product, a fluorescent dimer DBDA, is formed. The monochromic light from light source (150W Xe arc ramp) excites the DBDA and the excited light is transmitted through an optical fiber to be detected by a photodiode array. The change of fluorescence intensity is related to the change of peroxide concentration. The peroxidase is entrapped in Ca-alginate get on the inner surface. The biosensor has the linear signal range of 0.025mM-10.mM peroxide. By applying the step function of peroxide, reproducibility of biosensor has been investigated. The mathematical model is constructed by the combination of enzyme kinetics with reactor flow model. Good agreement is obtained between the experimental result and model prediction in the sensor signal.

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Effects of harvest time and added molasses on nutritional content, ensiling characteristics and in vitro degradation of whole crop wheat

  • Xia, Chuanqi;Liang, Yixun;Bai, Sarula;He, Yang;Muhammad, Aziz Ur Rahman;Su, Huawei;Cao, Binghai
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.3
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    • pp.354-362
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    • 2018
  • Objective: Wheat is an alternative to corn silage for ruminant feeding in northern China. This study examined the effects of harvest time and added molasses on nutritional content, ensiling characteristics and in vitro degradation of whole crop wheat (WCW). Methods: Fresh WCW at the milk-ripe stage was harvested at 0700 h (i.e., in the morning [Mo]) and 1700 h (i.e., in the afternoon [Af]), and then immediately used to prepare silage and make hay. Commercial molasses was added to Af WCW at 0%, 2%, 4%, and 6% (fresh weight) proportions. The WCW treated with molasses was mixed thoroughly prior to ensiling. Results: Dry matter (DM), neutral detergent fiber, water soluble carbohydrate (WSC) content (p<0.01), accumulative gas production in 72 h ($GP_{72h}$, 77.46 mL/g vs 95.15 mL/g) and dry matter disappearance in vitro (69.15% vs 76.77%) were lower (p<0.05), while crude protein (CP) content was higher for WCW silage (WCWS) compared to WCW (p<0.01). The propionic acid and butyric acid concentrations in WCWS from Mo WCW were 1.47% and 0.26%, respectively. However, the propionic and butyric acid concentrations were negligible, while the ammonia nitrogen/total nitrogen ($NH_3-N/TN$, p<0.01) concentration was lower and the rate of gas production at 50% of the maximum (17.05 mL/h vs 13.94 mL/h, p<0.05) was higher for Af WCWS compared to Mo WCWS. The incubation fluid's $NH_3-N$ concentration was lower in WCWS and Af WCW compared to Mo WCW (p<0.05). The CP and WSC content increased with increasing molasses levels (p<0.05). Furthermore, the pH (p<0.01) and time when gas production was 50% of the maximum (2.78 h vs 3.05 h, p<0.05) were lower in silage treated with 4% molasses than silage without molasses. Conclusion: Harvesting wheat crops in the afternoon and adding molasses at 4% level to WCW optimally improved ensiling characteristics, leading to well-preserved silage.

Recommendations of Environmental Reduction Factor of FRP Rebar for Durability Design of Concrete Structure (콘크리트 보강용 FRP 보강근의 내구성 설계를 위한 환경영향계수의 제안)

  • Park Chan-Gi;Won Jong-Pil;Kang Joo-Won
    • Journal of the Korea Concrete Institute
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    • v.16 no.4 s.82
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    • pp.529-539
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    • 2004
  • The corrosion of steel rebars has been the major cause of reinforced concrete deterioration. FRP(Fiber-reinforced polymer) rebar has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. However, FRP rebar is prone to deteriorate due to other degradation mechanisms than those for steel. The high alkalinity of concrete, for instance, is a possible degradation source. Therefore, the USA, Japan, Canada, UK. etc are using environmental reduction factor. Although difference design guidelines were drawn in many, including USA, Japan, Canada, UK etc, recommendations and coefficients that could take into account the long-term behavior of FRP reinforcement were not well defined. This study focuses on recommendation of environmental reduction factor of FRP rebar. Environment reduction factor were decided using durability test result. FRP rebars were subjected to twelve type of exposure conditions including alkaline solution, acid solution, salt solution and deionized water etc. The water absorption behavior was observed by means of simple gravimetric measurements and durability properties were investigated by performing tensile, compressive and short beam tests. Based on the experimental result, environmental reduction factor of hybrid FRP rebar(A), and (C) and CFRP rebar was decided as 0.85. Also, hybrid FRP rebar(B) and GFRP rebar were decided as 0.7 for the environmental reduction factor

Effect of V$_2$O$_5$ Addition on Microwave Dielectric Properties of (Zr$_{0.8}$,Sn$_{0.2}$)TiO$_4$ (V$_2$O$_5$의 첨가가 (Zr$_{0.8}$,Sn$_{0.2}$)TiO$_4$의 마이크로파 유전특성에 미치는 영향)

  • 이경호
    • Journal of the Microelectronics and Packaging Society
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    • v.8 no.1
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    • pp.27-32
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    • 2001
  • The effect of $V_2O_5$, a donor-type dopant on the degradation of quality factor of ($Zr_{0.8}, Sn_{0.2})TiO_4$was compared with Ta$_2$O$_{5}$ doped ($Zr_{0.8}, Sn_{0.2})TiO_4$ in terms of microstructure, electrical conductivity, and oxidation state of the dopant. It is well known that the addition of the donor type species such as $Ta_2O_5,Nb_2O_5, Sb_2O_5, WO_{3}$, increases the quality factor of ($Zr_{0.8}, Sn_{0.2})TiO_4$due to decrease the oxygen vacancy concentration. Unlike other dopants, however, the addition of $V_2O_5$ decreased the quality factor. The degradation of quality factor of ($Zr_{0.8}, Sn_{0.2})TiO_4$was resulted from the formation of grain boundary phase and $V_2O_5$rich fiber shaped secondary phase, and the increasing the oxygen vacancy concentration due to unstability of oxidation state of vanadium ions in ($Zr_{0.8}, Sn_{0.2})TiO_4$ceramic.c.

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