• Title/Summary/Keyword: chemical-recycled

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Cushioning Performance Analysis of Cushioning Materials for Vibration and Impact Condition (진동 및 충격조건에 대한 완충재별 완충성능 분석)

  • Oh, Jae-Young
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.15 no.1
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    • pp.1-6
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    • 2009
  • The impact absorption materials made of synthetic organic chemical product like Expanded Polystyrene(EPS), Expanded Polyethylene(EPE), Expanded Polyurethane(EPU), etc. have been used with general packaging material until the present. But nowadays, the use of these materials is intended to be decreased and to be recycled in connection with environmental pollution. In addition, it has been tried to substitute these materials with non-pollution materials(natural materials) like pulp mould, paper protectors, etc. At the same time, it is required to evaluate and analyze these cushioning materials for cushioning properties based on impact and vibration, in order to make an efficiency on the overall packaging system because they are generally being used by a random choice regardless of the properties of contents and cushioning materials. Therefore, this study provides analyzed data on cushioning properties of various cushioning materials against impact and vibration, and is intended to provide more efficient model for packaging system by minimizing their using amount through choosing an optimal cushioning material as well as intended to lead to the use of nonpollution materials in case these cushioning materials have same cushioning properties.

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Development of New Dihydropyran Linker for Solid-Phase Reaction

  • Ryu, Joon-Hyung;Jeong, Jin-Hyun
    • Archives of Pharmacal Research
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    • v.22 no.6
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    • pp.585-591
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    • 1999
  • The linker which plays a role in connecting a polymer with a scaffold has become an important part n solid-phase reaction. To develop a new linker for alcohols and carbohydrates, dihydropyran moiety was selected in this study. New linker, 1-($4^{l},5^{l}$-dihydro-5H-pyranyl)-7-hydroxyheptan-3-one (5) was synthesized via four steps from $\delta$-valerolactone. This can be called as DDHP-linked Wang resin due to double dihy-dropyran rings. To the one pyran ring of new linker 5 was added Wang resin and other alcohols and carbohydrates as scaffolds were then added successfully to the another pyran ring. Carbohydrate and hydroxyl resins were connected via new linker in a 70% loading yield. The detachment of glucose moiety in the presence of PPTS (2 equiv.) in 1:1 n-buteanol/1,2-dichloroethane at $60^{\circ}C$ for 12 h was carried out quantitatively. When certain combinatorial chemical works are carried out using this dihydropyran linker, Wang resin itself can be recovered. Its fact is particularly very important in industry, because recovered resins can be recycled.

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Method for expanding tobacco leaves with steam at high temperature and velocity (고온 증기를 이용한 잎담배의 팽화연구)

  • 김병구;김기환;정한주;유광근;이태호
    • Journal of the Korean Society of Tobacco Science
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    • v.17 no.1
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    • pp.68-78
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    • 1995
  • A study of expanding tobacco includes the steps of adjusting the moisture content of cut tobacco, without the use of exogenous impregnants by contacting the filler with a high velocity gaseous medium at elevated temperature such that heat is rapidly and substantially uniformly transferred from the medium to the filler for a total contact time sufficient to expand the tobacco leaves. Study is disclosed for drying and expanding cut tobacco by introducing the tobacco into an elongated tubular shaped conduit through which steam high temperature 150-35$0^{\circ}C$ and high velocity above the 18m1sec, super steam is recycled. moisture content of shreded tobacco leaves, immediately before treatment within the range of from 10% to 24% and, most preferably, within the range of from 18% to 21%. Expanding rate showed 70% in NC -82(B.3) and 42% in Burley -21(B.1) which is produced in 1993 under this condition. When expanding tobacco expanded tobacco did not change significally, but they were decreased at 27$0^{\circ}C$ very largely. The curtailment of cost price and physical and chemical properties of various items were improved in cigarettes. Key words : Expanding tobacco, Super steam tobacco expansion, Fast drying tobacco, High temperature treat tobacco, Puffing tobacco.

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Application of WCT(Wet Compaction Test) for Fiber Evaluation

  • Seo, Yung-B.;Ha, In-Ho;Lee, Chun-Han
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.5 s.118
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    • pp.9-15
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    • 2006
  • Wet compaction test (WCT) is a fiber evaluation method where wet fibers are compressed at one side of a cylinder and water drains out from the other side. The consistency of the fiber furnishes and their pressures are recorded during the test. In the previous study we found that WCT results always gave better coefficients of determination in fiber furnish drainage, and paper properties (density, tensile, tear, and burst strength) than those of WRV (water retention value). Fiber freeness and fiber length correlated well with drainage and tear strength of the furnishes, respectively; however, their correlations were very much improved by combining the WCT results. In this study, we used the WCT test for fractionated fiber furnishes to see whether improvement of the WCT is possible. We found that strength properties such as breaking length and burst index were correlated better with the fractionated long fiber furnishes. Drainage was greatly affected by the presence of short fiber furnishes. We used bleached chemical pulps (SwBKP, HwBKP), recycled pulp (OCC), and mechanical pulp (BCTMP) as fiber furnishes in this study. Fiber fractionation can be performed on-line in these days by using multifractor and WCT can be used as an on-line test in papermachine in the future.

Applicability of Composite Beads, Spent Coffee Grounds/Chitosan, for the Adsorptive Removal of Pb(II) from Aqueous Solutions

  • Choi, Hee-Jeong
    • Applied Chemistry for Engineering
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    • v.30 no.5
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    • pp.536-545
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    • 2019
  • An experiment was conducted to evaluate the adsorptive removal of Pb(II) from an aqueous solution using a mixture of spent coffee grounds and chitosan on beads (CC-beads). Various parameters affecting the adsorption process of Pb(II) using CC-beads were investigated. Based on the experimental data, the adsorption kinetics and adsorption isotherms were analyzed for their adsorption rate, maximum adsorption capacity, adsorption energy and adsorption strength. Moreover, the entropy, enthalpy and free energy were also calculated by thermodynamic analysis. According to the FT-IR analysis, a CC-bead has a very suitable structure for easy heavy metal adsorption. The process of adsorbing Pb(II) using CC-beads was suitable for pseudo-second order kinetic and Langmuir model, with a maximum adsorption capacity of 163.51 (mg/g). The adsorption of Pb(II) using CC-beads was closer to chemical adsorption than physical adsorption. In addition, the adsorption of Pb(II) on CC-beads was exothermic and spontaneous in nature. CC-beads are economical because they are inexpensive and also the waste can be recycled, which is very significant in terms of the continuous circulation of resources. Thus, CC-beads can compete with other adsorbents.

The Influence of Mechanical Properties with the Number of Recycling of Fiber-reinforced Thermoplastic Composites Damaged by Impact (충격에 의해 손상된 섬유강화 열가소성 수지 복합재료의 재활용 횟수에 따른 물성의 변화)

  • Bae, Kwak Jin;Lee, Joon Seok
    • Composites Research
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    • v.35 no.2
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    • pp.75-79
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    • 2022
  • In this study, the effect of mechanical and chemical properties of glass fiber reinforced thermoplastic (GFRTPs) according to the number of recycling was confirmed. The composite materials were manufactured through a hot press compression molding process using an E-glass chopped strand mat and a polypropylene film. Four specimens were named according to the number of recycled test repeat: First manufacture, 1st Recycle, 2nd Recycle, and 3rd Recycle. To investigate the mechanical properties of the prepared specimen, tensile test, flexural test, drop-weight impact test, differential scanning calorimetry (DSC), and field emission electron gun-scanning electron microscope (FE-SEM) was performed. As a result, as the number of recycling steps repeat, the degree of crystallization, tensile strength, elastic modulus, and flexural strength were increased, but the impact properties were greatly reduced.

Substitute Textile Preferences for Eco-Friendly Leather Goods: Focusing on Shoes and Bags

  • Kim, Ji-Soo;Na, Young-Joo
    • Science of Emotion and Sensibility
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    • v.25 no.2
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    • pp.55-70
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    • 2022
  • In the 21st century, the demand for eco-friendly leather, such as eco-leather and vegan leather, is steadily increasing. This study examines the influence of eco-friendliness on consumers' purchasing intentions and the possibility of eco-friendly changes in the fashion accessory market, which is dominated by leather material and leather substitutes. This study administered a questionnaire survey to 227 males and females between 20 and 60 years of age in Korea. With a 5-point Likert scale, data were collected on evaluation criteria when purchasing shoes and bags and purchasing intention of various leather substitute materials according to the democratic variables. The eco-friendliness attitude was divided into eco-consciousness and green behavior. As the eco-friendly attitude increased, most purchasing standards increased, but the purchasing criteria, such as trends, brands, and prices, did not correlate with the eco-friendly attitude. The eco-consciousness of a consumer had a high correlation with the design evaluation criteria, while the green behavior of the consumer aligned with durability and comfort criteria when purchasing a bag. There was a preference for recycled leather, vegetable leather, synthetic leather, and chemical leather, and the fabric type was ranked as natural fiber, biodegradable fiber, and synthetic fiber. Consumers with both green behavior and eco-consciousness are more likely to purchase biodegradable textiles and vegetable leather for the material of shoes and bags.

Review for Selenium Metabolism and Its Bioavailability in the Animal (셀레늄의 동물체내 대사 및 이용에 관한 고찰)

  • Kim, Wan-Young;Nho, Whan-Gook
    • Journal of Practical Agriculture & Fisheries Research
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    • v.6 no.1
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    • pp.90-101
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    • 2004
  • Se is essential for a number of enzymes that perform important metabolic functions necessary for good health. However, people in many countries do not appear to consume adequate amounts of Se to support the maximal expression of the selenoproteins and Se retention in the body of animals and humans is dependent on the ingested Se source such as organic and inorganic Se. Therefore, this review was discussed to explore metabolic characterization regarding intestinal absorption, bioavailability and selenoprotein synthesis according to animal species such as monogastrics including human beings and ruminants. Generally, organic Se provided to animals is more effective than inorganic Se in body retention for the animal owing to the difference of manner for intestinal absorption. But, Se absorption in ruminants depending on its chemical form still remained questioned by several microbial actions and feeding regimen in the rumen. And Se absorbed through small intestine is utilized for the synthesis of selenoproteins and/or retained as selenoamino acids in the body. Retained Se in the body may be recycled to synthesize selenoproteins as lacked of dietary Se. In conclusion, desirable forms of Se ingestion in the animal may be useful for Se fortification in animal products as well as well being for humans and animals.

Development of Magnetically Separable Immobilized Trypsin (자석에 의해 분리가 가능한 고정화 Trypsin 개발)

  • Ryu, Ji-Soon;Lee, Jung-Heon
    • KSBB Journal
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    • v.23 no.4
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    • pp.350-354
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    • 2008
  • Magnetically separable immobilized trypsin was developed and their biocatalytic activity was evaluated for the different immobilization media. The activity, recyclability, pH effect, and stability of immobilized enzymes were evaluated for the different supporting media. The biocatalytic activity of immobilized trypsin was highest with magnetically separable polyaniline (PAMP), and Vm and Km of PAMP were 0.169 mM/min and 0.263 mM respectively. With increasedpH, the biocatalytic activity increased for all supporting materials used. Immobilized enzymes were recycled and recycle activities were over 90% of their original activity after ten times reuse. The operational stabilities of enzymes were greatly improved with enzyme immobilization.

Oxidation of Benzyl Ethers in Sodium Hypochlorite Mediated Piperidine-1-oxyl System (촉매량의 Piperidine-1-oxyl과 NaOCl계에서 벤질 에테르 유도체들의 산화 반응)

  • Cho, Nam Sook;Park, Chan Heun
    • Journal of the Korean Chemical Society
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    • v.39 no.8
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    • pp.657-665
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    • 1995
  • The oxidation of various benzyl ethers and benzyl alkyl ethers to benzoates has been studied in two-phase system of $CH_3CO_2Et$ and aqueous NaOCl (6.6 mol eq.). The oxidant N-oxo-4-methoxy-2,2,6,6-tetramethylpiperidium bromide (N-oxoammonium salt) was prepared in situ and recycled by addition of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (0.03 mol eq., 4-methoxy-TEMPO), co-catalyst KBr (0.03mol eq.) and second oxidant NaOCl. Thus the catalytic amount of 4-methoxy-TEMPO was used. An adjustment of the pH value of below 8.0 was also required for this reaction with 2.5 hr of reaction time at 0∼5$^{\circ}C$. Under these conditions benzyl ethers were oxidized to benzoates. The selectivity of oxidation of benzyl alkyl ethers is dependent on the acidity of hydrogen and steric effect of alkyl group.

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