• Title/Summary/Keyword: biodegradable

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Advances in Biodegradable Polymers for Drug Delivery Systems

  • Yong Kiel sung;Kim, Sung-Wan
    • Macromolecular Research
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    • v.8 no.5
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    • pp.199-208
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    • 2000
  • The recent development of biodegradable polymers for drug delivery system (DDS) has been investigated. The biodegradable polymers for DDS are mainly discussed in two categories: one category is natural biodegradable polymers such as polysaccharides, modified celluloses, poly(${\alpha}$-amino acid)s, modified proteins, and microbial biodegradable polymers; the other is synthetic biodegradable polymers such as poly(ester)s, poly(ortho ester)s, poly(phosphazene)s, poly(anhydride)s, poly(alkyl cyanoacrylate)s, and multiblock copolymers. The bioconjugate polymeric drug delivery systems have been also proposed for the design of biocompatible polymeric controlled drug delivery.

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Respirometry for the Assessment of Organics Biodegradability in Municipal Wastewater: I. Respirometry (호흡률법에 의한 하수의 생분해 특성 평가: I. 호흡률법)

  • Kim, Dong Han;Kim, Hee Jun;Chung, Tai Hak
    • Journal of Korean Society of Water and Wastewater
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    • v.18 no.1
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    • pp.29-36
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    • 2004
  • Organics may be divided into biodegradable and nonbiodegradable fractions on the basis of biodegradability. Biodegradable organics may be subdivided into readily and slowly biodegradable fractions. As this biodegradability of organics in municipal wastewater has a great influence on the efficiency of a biological nutrient removal process, it has been assessed by respirometry. The respirometer, which consisted of a respiration chamber and a respiration cell, was used to measure the respiration rate of biomass utilizing the readily biodegradable organics. The readily biodegradable organics are about 10% of the COD in municipal wastewater. The adequate ratio of wastewater to sludge volume and the concentration of sludge are required in measuring the respiration rate due to the readily biodegradable organics. By using a biochemical oxygen demand test, the slowly biodegradable organics including biomass are estimated about 66% of COD. The soluble inert organics are about 11% of COD. On the basis of mass balance, the particulate inert organics are estimated about 13% of COD.

Analysis of economic effects of expanding of biodegradable fishing gear (생분해 어구 보급 확대에 따른 경제적 효과 분석)

  • PARK, Subong;KIM, Hyun Young;YANG, Yong Su;EUH, Seung Seob;KANG, Da Young
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.4
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    • pp.372-377
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    • 2019
  • Recently, as the global problem of marine debris and marine plastics is getting serious, various ways to solve them have been proposed, and the use of the biodegradable fishing gear is proposed as an alternative. Currently, 13 types of biodegradable fishing gears are available, but their penetration rate is only 8.7%. However, the need for the use of the biodegradable fishing gear is growing as awareness of protecting marine ecosystems is growing. Therefore, in this study, the economic effects of the expansion of biodegradable fishing gear distribution in Korea's coastal areas were analyzed through the conservation of marine ecosystems, augmentation of fisheries resources, and augmentation of fishing efficiency. According to the analysis, the economic effects of 52,795 million won, 105,590 million won, and 158,385 million won was generated as the distribution of biodegradable fishing gear were expanded to 10%, 20% and 30% across all gill net and trap.

Catch characteristics of the biodegradable gill net for flounder (생분해성 가자미 자망어업의 어획 특성)

  • Bae, Bong-Seong;Cho, Sam-Kwang;Park, Seong-Wook;Kim, Seong-Hun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.310-321
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    • 2012
  • There are many studies of the biodegradable net for fishing to prevent marine pollution in Korea and the snow crab gill nets is developed effectively. Recently, the biodegradable gill net for fishes is being developed. This study is the experiment of the catch characteristics for the biodegradable flounder gill net. The 8 experiments were carried out using the nylon gill net and the biodegradable gill net in from August to October, 2011 in the southern East Sea. The results obtained from the above approaches are summarized as follows; A total of 16 species was caught with most dominant species of Cleisthenes pinetorum followed by Liparis tanakai, Glyptocephalus stelleri, Buccinum striatissimum and Dasycottus setiger. A total of catch of the nylon net was 342,885g and that of the biodegradable net was 236,857g. Thus catch of the nylon net was 1.45 times more than that of the biodegradable net. The length composition of Cleisthenes pinetorum, caught by the biodegradable net was very similar to that of nylon. As a result of analysis on the effect of submerged time, small fish escaped more easily than large fish as the submerged time is getting longer. And catches of the biodegradable net was less than the nylon net's as higher as wave height. Wave height was more influential factor for fishing capacity than submerged time based on the results of a comparison between catch difference of two kinds of gill nets and catch characteristics.

Economic analysis of biodegradable snow crab gill net model project (생분해성 대게 자망 시범사업의 경제성 분석)

  • Park, Seong-Kwae;Park, Seong-Wook;Kwon, Hyeok-Jun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.4
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    • pp.276-286
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    • 2009
  • The main purpose of this research is to analyze economic feasibility of biodegradable sonw crab gill net model project. The results of benefit/cost analysis show that use of the biodegradable gear is economically feasible. Assuming that the rate of gill net lost is 5 percent, net present value was estimated 311,898,282-590,533,375won, benefit-cost ratio 1.816-1.923 and internal rate of return 7.96-10.59%. The development and diffusion of biodegradable fishing gear appear to make a significant contribution to fisheries resource conservation and marine ecosystem protection. In addition, biodegradable gear production firms may have a good opportunity of exporting it to other coastal states, depending on the progress of WTO subsidy negotiation.

Biodegradable polymeric drug delivery systems

  • Jeong, Seo-Young;Kim, Sung-Wan
    • Archives of Pharmacal Research
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    • v.9 no.2
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    • pp.63-73
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    • 1986
  • The use of biodegradable polymetric materials as drug carriers is a relatively new dimension in polymeric drug delivery systems. A number of biodegradable or bioerodible polymers, such as poly(lactic/glycolic acid) copolymer, poly($\alpha$-amino acid), polyanhydride, and poly (ortho ester) are currently being investigated for this purpose. These polymers are useful for matrix and reservoir-type delivery devices. In addition, when chemical functional groups are introduced to the biodegradable polymer backdone, such as poly (N-(2-hydroxypropyl) methacrylamide), the therapeutic agent can be covalently bound directly or via spacer to the backbone polymer. These polymer/drug conjugates represent another new dimension in biodegradable polymeric drug delivery systems. In addition, examples of biodegradable polymeric durg delivery systems currently being investigated will be discussed for the purpose of demonstrarting the potential importance of this new field.

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Tip Plasty using Biodegradable Plate as a Columella Strut (비주 버팀목으로 흡수성 고정판을 이용한 비첨 성형술)

  • Kim, Soo-Young;Lee, Soo-Hyang;Hwang, Eun-A;Choi, Hyun-Gon;Kim, Soon-Heum;Shin, Dong-Hyeok;Uhm, Ki-Il
    • Archives of Plastic Surgery
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    • v.37 no.3
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    • pp.259-264
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    • 2010
  • Purpose: Most surgeons have used autogenous cartilage for columella strut graft. But the supply of autogenous cartilage is often limited. So, this study is to investigate the usefulness of biodegradable plate as columella strut material. Methods: We studied 19 patients who have secondary cleft nasal deformity. Patients were divided into two groups. Group A patients who were not closed their growth plate underwent columella strut graft only with biodegradable plate through endonasal approach. The biodegradable plate was inserted between nasal tip and anterior nasal spine. Group B patients were closed their growth plate. They had an operation for columella strut graft with biodegradable plate fixed with autogenous conchal cartilage. If nasal tip projection was insufficient, we performed additionally onlay graft on nasal tip with autogenous soft tissue or remnant cartilage. Results: As a result of mean 14 months follow-up, we achieved a good nasal tip projection, narrowing of interalar distance and symmetrical nostril shape. No specific complications were reported except 2 cases, which were the extrusion of biodegradable plate into the nasal cavity and Staphylococcus aureus infection. Conclusion: The columella strut graft using biodegradable plate is simple and effective method. Biodegradable plate can be a good substitute for columella strut in patients who can not use autogenous cartilages.

Effect of Biodegradable Mulch Film on Soil Microbial Community

  • Moon, Jin-Young;Song, Jae-Ki;Shin, Jung-Ho;Cho, Yong-Cho;Bae, Jin-Woo;Heo, Jae-Young;Kang, Hang-Won;Lee, Young-Han
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.2
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    • pp.125-131
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    • 2016
  • The biodegradable film application can escape from plastic environmental pollution. This experiments studied the effect of biodegradable mulch film on the soil microbial community using fatty acid methyl ester method in soybean production field. The soil $NO_3$-N content in polyethylene mulch film (PE) soil was significantly higher than biodegradable mulch film soil (p < 0.05). The soil microbial community of Gram negative bacteria showed significantly higher in biodegradable mulch film soil than PE mulch film soil (p < 0.05). In addition, biodegradable mulch film soil had significantly low ratio of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ compared with those of PE mulch film soil (p < 0.05), indicating that microbial stress decreased. The ratio of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ should be considered as a potential responsible factor for the obvious differentiation that was observed between the biodegradable mulch film soil and PE mulch film soil in a upland field. The results of this experimentation show the potential of using biodegradable mulch film in place of PE.

Studies on the Development of Biodegradable Plastics and Their Safety and Degradability (생붕괴성 플라스틱 포장재의 제조 및 제조된 소재의 안전성과 분해성 연구)

  • You, Young-Sun;Han, Jung-gu;Lee, Han-na;Park, Su-il;Min, Sea-Cheol
    • Food Engineering Progress
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    • v.15 no.3
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    • pp.257-261
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    • 2011
  • Biodegradable plastics were developed using biodegradable pellets made of corn stalk and rice husk and their safety as food packages and their biodegradability against light (ultraviolet (UV)), heat, and fungi were evaluated. Four kinds of 50-${\mu}m$ biodegradable plastics were produced by extruding the mixtures of the biodegradable pellets, low-density polyethylene (LDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE) with different compositions. Developed biodegradable plastics were safe to be used as food packages. The initial tensile strength and percentage elongation of the plastics were similar to those of LDPE, but the values decreased with increased their exposure time to UV and heat. The fungal biodegradability of the biodegradable plastics was higher than that of LDPE. The biodegradability of the biodegradable plastics shows the potential for them to be used as sustainable food packages.

Cutting Technique for Biodegradable Rope using a CW CO2 Laser with TEM00 mode

  • Lee, Dong-Gil;Kim, Seong-Hun;Park, Seong-Wook;Yang, Yong-Su;Xu, Guo-Cheng
    • Journal of Electrical Engineering and Technology
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    • v.7 no.4
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    • pp.576-581
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    • 2012
  • A 23 W continuous wavelength $CO_2$ laser system exited by a high-frequency LCC resonant converter is adapted to cut a biodegradable rope fabricated with polybutylene succinate. As the biodegradable rope consists of three twisted strands, the thickness changes relative to the position of the laser beam and we thus propose a method to determine exact cutting depth. In order to obtain the parameters related to the rope cutting, the experimental and theoretical cutting depths are compared and analyzed for a range of laser heat sources. The melted thickness and groove width of the cut biodegradable rope are also examined. The proposed theoretical cutting depth depends on the incident power and target velocity ratio. From these experimental results, the biodegradable rope with a diameter of 22 mm can be cut with a heat source of 50 J/cm resulting in a melted thickness of 1.96 mm and a groove width of 0.65 mm. The laser system is shown to be perfect tool for the processing of biodegradable rope without the occurrence of raveling.