• Title/Summary/Keyword: Biodegradable Material

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The effect of different fluoride application methods on the remineralization of initial carious lesions

  • Byeon, Seon Mi;Lee, Min Ho;Bae, Tae Sung
    • Restorative Dentistry and Endodontics
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    • v.41 no.2
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    • pp.121-129
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    • 2016
  • Objectives: The purpose of this study was to assess the effect of single and combined applications of fluoride on the amount of fluoride release, and the remineralization and physical properties of enamel. Materials and Methods: Each of four fluoride varnish and gel products (Fluor Protector, FP, Ivoclar Vivadent; Tooth Mousse Plus, TM, GC; 60 Second Gel, A, Germiphene; CavityShield, CS, 3M ESPE) and two fluoride solutions (2% sodium fluoride, N; 8% tin(ii) fluoride, S) were applied on bovine teeth using single and combined methods (10 per group), and then the amount of fluoride release was measured for 4 wk. The electron probe microanalysis and the Vickers microhardness measurements were conducted to assess the effect of fluoride application on the surface properties of bovine teeth. Results: The amount of fluoride release was higher in combined applications than in single application (p < 0.05). Microhardness values were higher after combined applications of N with FP, TM, and CS than single application of them, and these values were also higher after combined applications of S than single application of A (p < 0.05). Ca and P values were higher in combined applications of N with TM and CS than single application of them (p < 0.05). They were also increased after combined applications of the S with A than after single application (p < 0.05). Conclusions: Combined applications of fluoride could be used as a basis to design more effective methods of fluoride application to provide enhanced remineralization.

Catch and cluster analysis according to net materials of gillnet for the Pacific herring in the coastal waters of Samcheok, Korea (삼척 연안 청어자망의 그물 재질에 따른 어획과 군집 분석)

  • AN, Heui-Chun;BAE, Jae-Hyun;PARK, Jong-Myung;HONG, Sung-Eic;KIM, Seong-Hun;PARK, Hae-Hoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.3
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    • pp.348-354
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    • 2015
  • Experiments for catch and cluster analysis on the catch by gillnet for the Pacific herring were conducted using traditional nylon net (PA) and developing biodegradable net (PBS) with different monofilaments of #2 (=0.23 mm) and #3 (=0.28 mm) in diameter between 2011 and 2012, and of #2, #2.5 and #3 in 2013 in the eastern coastal waters of Samcheok, Korea. The total catch during the experiments was 3,337kg in weight and 16,757 individuals in number. Though the catch ratio of the Pacific herring in 2011 and 2012 was 97.4% and 98.7%, respectively, that of the Pacific herring in 2013 was 73.6% as the biggest and followed by goldeye rockfish (8.6%), black edged sculpin (8.4%), atka mackerel (7.2%) and Alaska cod (1.0%). The ANOVA analysis on the total catch in relation to net material showed that there was not statistically significant difference at the 5% level between nylon net (PA) and biodegradable net (PBS) (p=0.91). With the cluster analysis on the catch in relation to net material (PA, PBS) and twine thick (#2, #3), it showed the influence of net material on the catch was greater than that of twine diameter in this experiment. From the test of homogeneity on the catch by the gillnet with PA and PBS in which several species were caught in 2013, there was not statistically significant homogeneity in relation to net material (p<0.005). That meant the traditional gillnet of nylon (PA) was more efficient than the biodegradable (PBS) gillnet to catch several kinds of fish, however the PBS gillnet was better than the PA gillnet to catch the target Pacific herring.

Influence of the Biodegradable Packaging Material on the Rheological Properties of Eggs (생분해성 포장재질이 달걀의 물성에 미치는 영향 연구)

  • Kim, Ji-Hyun;Park, Jong-Shin;Kim, Byung-Yong
    • Applied Biological Chemistry
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    • v.40 no.6
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    • pp.525-530
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    • 1997
  • The changes in rheological properties of egg white stored in biodegradable package were investigated by pH change, failure stress and stress relaxation curve, and compared with control without package and complex PE. Initial pH of egg white stored in biodegradable package changed from 8.39 to 9.3 after 8 day storage, showing similar trend in pH change as that of control without package. Initial 14.25 N failure stress was changed into 6.76 N in biodegradable package and 9.31 N in control. Complex PE, having a relatively low gas permeability compared to biodegradable package, showed less pH changes from 8.30 to 8.81, but a greater decrease in failure stress into 5.29 N, indicating more deteriorating effect in complex PE package. Viscoelastic constants, such as elastic constant and viscous constant, obtained from stress-relaxation curve by three element Maxwell model were not significantly different between control and biodegradable package, but eggs stored in complex PE showed greater changes during storage. Therefore, the permeability seems to be the major factors to influence the rheological properties of egg and biodegradable packaging materials showed a potential substitute package for eggs.

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Characteristics of Anaerobic Biodegradability in Hydro-thermal Hydrolysate of Sewage Sludge (하수 슬러지 수열탄화액의 혐기적 유기물 분해 특성 연구)

  • Oh, Seung-Yong;Yoon, Young-Man
    • Journal of the Korea Organic Resources Recycling Association
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    • v.25 no.1
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    • pp.35-45
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    • 2017
  • In order to improve the anaerobic digestion efficiency of the sewage sludge, the methane potential of the hydrolysate generated from the hydro-thermal reaction at 170, 180, 190, 200, 210, $220^{\circ}C$ was analyzed and the constitutional characteristics of the organic materials were estimated by dividing organic materials of hydro-thermal hydrolysate into easily biodegradable, decomposition resistant, and non-biodegradable organic materials applying the parallel first order kinetics model. The ultimate methane potential of sewage sludge hydro-thermal hydrolysate increased to 0.39, 0.39, 0.40, 0.44, 0.45, and $0.46Nm^3/kg-VS_{added}$ as hydro-thermal reaction temperature increased from 170, 180, 190, 200, 210, $220^{\circ}C$. It has been shown that the organic matter of sewage sludge is solubilized to increase the content of biodegradable organic material($VS_B$). The easily degradable organic matter($VS_e$) content was highest at hydro-thermal reaction temperature of 200 and $210^{\circ}C$, and optimum hydro-thermal reaction temperature for organic matter solubilization of sewage sludge was in the range of $200{\sim}210^{\circ}C$. In addition, the amount of biodegradable organic material($VS_B$) and easily biodegradable organic matter ($VS_e$) in the hydrolysate of sewage sludge was the highest at hydro-thermal reaction temperature of $200^{\circ}C$.

Feasibility Study on the Use of Vegetable Oil (Natural Ester) in Malaysia Power System Transformers

  • Suleiman, Abubakar A.;Muhamad, Nor Asiah Binti
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.3
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    • pp.113-116
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    • 2014
  • Power transformer insulation oil is critical to the useful life of the transformer. Although mineral base insulation oil is the most common type of transformer insulation oil in use, environmental and safety concerns has encouraged the development of biodegradable alternatives. Today, $Envirotemp^{(R)}\;FR3^{TM}$ is in commercial use and this study is aimed at ascertaining the possibility of applying the oil in Malaysia power transformers. A sample of $Envirotemp^{(R)}\;FR3^{TM}$ was tested to measure and compare the technical (including electrical, chemical and physical) properties of the oil according to Malaysian standards. The study found that the oil sample had better qualities, such as higher dielectric strength, lower dissipation factor, higher flash and fire points, higher moisture absorption capability, and less dissolved gases composition amongst others. However, it was also ascertained that further development in this area could be hindered due to Malaysia's lack of standards for biodegradable oil.

Synthesis of biodegradable films obtained from rice husk and sugarcane bagasse to be used as food packaging material

  • Gupta, Himanshu;Kumar, Harish;Kumar, Mohit;Gehlaut, Avneesh Kumar;Gaur, Ankur;Sachan, Sadhana;Park, Jin-Won
    • Environmental Engineering Research
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    • v.25 no.4
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    • pp.506-514
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    • 2020
  • The current study stresses on the reuse of waste lignocellulose biomass (rice husk and sugarcane bagasse) for the synthesis of carboxymethyl cellulose (CMC) and further conversion of this CMC into a biodegradable film. Addition of commercial starch was done to form biodegradable film due to its capacity to form a continuous matrix. Plasticizers such as Glycerol and citric acid were used to provide flexibility and strength to the film. Biopolymer film obtained from sugarcane bagasse CMC showed maximum tensile strength and elongation in comparison to the film synthesized from commercial CMC and CMC obtained from rice husk. It has been observed that an increase in sodium glycolate/NaCl content in CMC imposed an adverse effect on tensile strength. Opacity, moisture content, and solubility of the film increased with a rise in the degree of substitution of CMC. Therefore, CMC obtained from sugarcane bagasse was better candidate in preparing biopolymer/biocomposite film.

Preparation and Properties of Celluose Diacetate/Starch Composite (Cellulose Diacetate/Starch 복합체의 제조 및 물성)

  • Lee, Sang-Yool;Lee, Seung-Kyung;Lim, Hwan-Kyu;Kye, Hyoung-San;Lee, Young-Kwan
    • Polymer(Korea)
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    • v.30 no.6
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    • pp.532-537
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    • 2006
  • In order to successfully meet the environmental and recycling problems, natural polymer and their derivatives are recognized as a promising biodegradable material. In this study, the biodegradable composites of cellulose diacetate and starch were prepared, and their physical and thermal properties were investigated. For the melting processing, triacetine was added as a plasticizer into the composites. The processability of cellulose diacetate was further enhanced by increasing the amount of starch in the composites. The tensile stress and Young's modulus were decreased and elongation was increased with increasing the amount of starch in them. A $T_g$ value was decreased with increasing the amount of starch in the composites. Also, the morphology of the composites were observed with the SEM.

Histological Changes in the Normal Tissues of Rat after Local Application of the Holmium-166 Chitosan Complex attached to Biodegradable Solide Material (생분해성 고형물에 흡착시켜 실험동물에 국소 투여한 홀미움-166 Chitosan 복합체의 투여량, 기간 및 부위에 따른 조직의 괴사 정도와 양상)

  • 이종석;최창운;정위섭;우광선;이태섭;이수진;임수정;김은희;임상무
    • Proceedings of the Korean Nuclear Society Conference
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    • 2001.05a
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    • pp.441-441
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    • 2001
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The Analysis of Environmental Impact Load by Fibrous Raw Materials and Wet-end Additives in Papermaking Process (제지공정 섬유상 원재료 및 공정 첨가제의 환경오염 부하 분석)

  • Kim, Hyoung-Jin;Shin, Dong-Uk
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.3
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    • pp.50-58
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    • 2005
  • It is generally known that paper industry is the second largest industry in the use of process water, and also have the highest environmental impact load in the contaminant sources. Paper is produced from the mixtures composed of 1% fibrous raw materials and 99% water. The optimum use of process water effects on the quality properties of paper and the environmental impact load of waste water treatment. In this research, the kinds of fibrous raw material & additives used in the paperboard production line were investigated, and the quantification of environmental loads and the environmental effects of process water on COD potential were evaluated. The NBDCODs were also analyzed from process water by the method of waste water treatment in paper mill and applied for the optimum use of recycling water, and zero effluent process. In the fibrous raw materials, KOCC caused the highest COD potentials, and sack paper & UKP was comparatively low. The NBDCOD of KOCC largely reduced after biological treatment because of easily biodegradable properties, but AOCC contained non-biodegradable materials. In chemical additives, COD was high in turns of rosin>starch>deaeration agent>dye, NBDCOD greatly reduced in starch and deaeration agent. In the case of 2 kinds of paperboard product, the COD potentials was mainly high in starch, AOCC and KOCC.