• Title/Summary/Keyword: Chemical quality

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Low-Temperature Plasma Enhanced Chemical Vapor Deposition Process for Growth of Graphene on Copper

  • Ma, Yifei;Jang, Hae-Gyu;Chae, Hui-Yeop
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.433-433
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    • 2013
  • Graphene, $sp^2$-hybridized 2-Dimension carbon material, has drawn enormous attention due to its desirable performance of excellent properties. Graphene can be applied for many electronic devices such as field-effect transistors (FETs), touch screen, solar cells. Furthermore, indium tin oxide (ITO) is commercially used and sets the standard for transparent electrode. However, ITO has certain limitations, such as increasing cost due to indium scarcity, instability in acid and basic environments, high surface roughness and brittle. Due to those reasons, graphene will be a perfect substitute as a transparent electrode. We report the graphene synthesized by inductive coupled plasma enhanced chemical vapor deposition (ICP-PECVD) process on Cu substrate. The growth was carried out using low temperature at $400^{\circ}C$ rather than typical chemical vapor deposition (CVD) process at $1,000^{\circ}C$ The low-temperature process has advantage of low cost and also low melting point materials will be available to synthesize graphene as substrate, but the drawback is low quality. To improve the quality, the factor affect the quality of graphene was be investigated by changing the plasma power, the flow rate of precursors, the scenario of precursors. Then, graphene film's quality was investigated with Raman spectroscopy and sheet resistance and optical emission spectroscopy.

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Effect of fine fillers from industrial waste and various chemical additives on the placeability of self-compacting concrete

  • Utepov, Yelbek;Akhmetov, Daniyar;Akhmatshaeva, Ilnur
    • Computers and Concrete
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    • v.25 no.1
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    • pp.59-65
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    • 2020
  • The premise for the study reflected in this article is the need to dispose of industrial waste, which is increasingly being used in the construction materials industry. Also, dynamically developing building industry demands attention of scientists and a direction of their works on improvement of the technology of carrying out construction works. Thus, the article is devoted to studying the influence of various chemical additives and fine fillers (industrial wastes) available in Kazakhstan on self-compacting concrete (SCC) mixtures and its rheological, physical, and technical properties. According to the studies, revealed the most efficient type of fine-dispersed filler and the most optimal type of chemical additive to enable obtaining a high-quality SCC mixture based on local raw materials. As a result, the use of microsilica in comparison with other industrial wastes resulted in a conglomerate with high compressive strength of SCC at early terms of curing. In terms of economic efficiency and quality improvement, the results of study are of practical value for the manufacturers of ready-mixed concrete operating in Kazakhstan.

A Study on the Quality Properties of the Expansive For Dry-Shrinkage Compensation of the Floor Mortar (온돌바닥 모르터의 건조수축보상을 위한 팽창제의 품질특성 연구)

  • 이웅종;이종열;정연식;이순기;정성철
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.155-160
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    • 2000
  • In this paper, we investigated quality properties for the expansive of the CaO-$CaSO_4$ family which used to compensate dry-shrinkage in the floor mortar of On-Dol heating System. This experimental study established the mix condition with quantity of the expansive and is to investigate the relativity between the compress strength and the length change and the relativity between the chemical properties and the length change with the analysis of the physical and chemical properties. As a result of the study, the expansive is controlled by more the CaO than the $CaSO_4$. The relativity between the compress strength and the length change is expressed by exponential function, showing that if the expansive performance is increased, the compress strength is decreased. And the relativity between the chemical properties and the length change is only relative the quantity of the F-CaO among the chemical properties, is expressed by the second order function, showing that if the F-CaO is increased, the expansive performance is increased.

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Raman Chemical Imaging Technology for Food and Agricultural Applications

  • Qin, Jianwei;Kim, Moon S.;Chao, Kuanglin;Cho, Byoung-Kwan
    • Journal of Biosystems Engineering
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    • v.42 no.3
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    • pp.170-189
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    • 2017
  • Purpose: This paper presents Raman chemical imaging technology for inspecting food and agricultural products. Methods The paper puts emphasis on introducing and demonstrating Raman imaging techniques for practical uses in food analysis. Results & Conclusions: The main topics include Raman scattering principles, Raman spectroscopy measurement techniques (e.g., backscattering Raman spectroscopy, transmission Raman spectroscopy, and spatially offset Raman spectroscopy), Raman image acquisition methods (i.e., point-scan, line-scan, and area-scan methods), Raman imaging instruments (e.g., excitation sources, wavelength separation devices, detectors, imaging systems, and calibration methods), and Raman image processing and analysis techniques (e.g., fluorescence correction, mixture analysis, target identification, spatial mapping, and quantitative analysis). Raman chemical imaging applications for food safety and quality evaluation are also reviewed.

Evaluation of Chemical Resistance of Epoxy Resin Injection Type Leakage Repairing Materials Applied to Underground Concrete Structures (지하 콘크리트 구조물에 적용되는 에폭시 수지계 주입형 누수보수재료의 화학저항성능 평가)

  • Park, So-young;Kim, Soo-Yeon;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.41-42
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    • 2017
  • In this study, an investigation was made to study the chemical resistance performance of epoxy resin injection type leakage repair material used in the Korean construction market in accordance to the test method outlined in "ISO TS 16774, Part 2; Test Method for Chemical Resistance." This is a new standard document used for quality control method of injection type repair material used for leakage cracking of underground concrete structures. The results of this study can be expected to be utilized as reference data that can be used for quality improvement of the maintenance methods for future construction.

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Influence of Drought Stress on Chemical Composition of Sesame Seed

  • Kim, Kwan-Su;Ryu, Su-Noh;Chung, Hae-Gon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.1
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    • pp.73-80
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    • 2006
  • Sesame (Sesamum indicum L.) seeds contain abundant oil and antioxidative lignans related to the seed quality. To evaluate the potential effects of drought stress on the chemical composition of sesame seeds, eighteen cultivars were imposed water-deficit condition by withholding irrigation during 15 days at podding and maturing stage, compared with well-watered plants as control in seed yield and chemical composition. Drought treatments showed great decrease of seed yield with not affecting seed weight. The contents of sesamin and sesamolin decreased while lignan glycosides inversely increased in response to drought stress. Oil content was not significantly changed by drought treatment in spite of its slight decrease. In case of fatty acid composition, there were significant differences in increase of oleic acid while inverse decrease of linoleic acid under drought stress condition. These results demonstrate that the chemical composition of sesame seed may be modified with drought stress. In particular, the increase of sesaminol glucosides with strong antioxidative activity was observed.

Pretreatment of low-grade poly(ethylene terephthalate) waste for effective depolymerization to monomers

  • Kim, Yunsu;Kim, Do Hyun
    • Korean Journal of Chemical Engineering
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    • v.35 no.11
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    • pp.2303-2312
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    • 2018
  • Pretreatment process of silica-coated PET fabrics, a major low-grade PET waste, was developed using the reaction with NaOH solution. By destroying the structure of silica coating layer, impurities such as silica and pigment dyes could be removed. The removal of impurity was confirmed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The pretreated PET fabric samples were used for depolymerization into its monomer, bis(2-hydroxylethyl) terephthalate (BHET), by glycolysis with ethylene glycol (EG), and zinc acetate (ZnAc) catalyst. The quality of BHET was confirmed by DSC, TGA, HPLC and NMR analyses. The highest BHET yield of 89.23% was obtained from pretreated PET fabrics, while glycolysis with raw PET fabric yielded 85.43%. The BHET yield from untreated silica-coated PET fabrics was 60.39%. The pretreatment process enhances the monomer yield by the removal of impurity and also improves the quality of the monomer.

Growth Performance and Meat Quality of Broiler Chickens Supplemented with Bacillus licheniformis in Drinking Water

  • Liu, Xiaolu;Yan, Hai;Lv, Le;Xu, Qianqian;Yin, Chunhua;Zhang, Keyi;Wang, Pei;Hu, Jiye
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.5
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    • pp.682-689
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    • 2012
  • A feeding trial was conducted to investigate effects of Bacillus licheniformis on growth performance and meat quality of broilers. Nine hundred one-d-old broiler chicks were randomly assigned to 3 experimental groups with three replicate pens of 100 broiler chicks. Three treatments were i) control, ii) basal diets supplemented with 1 ml of B. licheniformis for each in feed water per day iii) basal diets supplemented with 2 ml of B. licheniformis per chick in feed water per day. The supplementation of B. licheniformis significantly increased body weight in grower chickens (p<0.05), and significantly improved the feed conversion in 3 to 6 and 0 to 6 wk feeding period compared with the control group (p<0.05). Additionally, the supplement also resulted in increased protein and free amino acid contents, and decreased fat content in chicken breast fillet (p<0.05). Furthermore, improvement in sensory attributes was observed in broilers fed with the probiotic. In conclusion, B. licheniformis treatments resulted in a significant increase (p<0.05) in broiler productivity based on an index taking into account daily weight gain and feed conversion rate. Meanwhile, the probiotic contributed towards an improvement of the chemical, nutritional and sensorial characteristics of breast fillet. Overall, the study indicates that B. licheniformis can be used as a growth promoter and meat quality enhancer in broiler poultry.

Efficacy of Cyanobacterial Biofertilizer (CBB) on Leaf Yield and Quality of Mulberry and its Impact on Silkworm Cocoon Characters

  • Dasappa D.M. Ram Rao;Ramaswamy S.N.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.13 no.1
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    • pp.15-22
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    • 2006
  • An experiment was conducted to study the efficiency of cyanobacterial biofertilizer (CBB) with chemical (NPK) fertilizer on quantitative and qualitative characters of mulberry variety Kanva-2. Their influences on silkworm growth and cocoon characters were also studied. Ten different CBB and NPK fertilizer treatments were given to 5000 plants of established mulberry garden. Treatments were of four types viz., (i) T1 to T7: single and combination dose of CBB+50% NPK (ii) T8: combination dose of CBB + 25%NPK, (iii) T9: CBB only and (iv) T10: control-l00% NPK. Soil pH decreased and nutrients status increased in CBB (T1- T9) treated plots. Average of ten crops data on quantitative traits revealed that T7 (CBB [N. muscorum (1.0 g), A. variahilis (1.0) and S. millei (1.0 g)] + 50% NPK) was very effective in improving growth parameters. Leaf yield was also found high in treatment T7 (32.12 tons/ha/yr.) followed by T10 (31.17 tons/ha/yr.) and T8 (27.67 tons/ha/yr.). Leaf quality characters were found high in T7 and low in T9. Most of the quality traits in T7 are on par with control no. The results revealed that reduction in the dose of chemical fertilizers in T7 did not affect the leaf yield and leaf quality traits of mulberry. This clearly indicates that the efficiency of CBB (T7) provides nitrogen, increases essential nutrients available in soil, maintain soil pH and supply growth substances required for the improvement of leaf yield and leaf quality of mulberry. Bioassay study also revealed no significant difference in silkworm growth and cocoon characters between treatments T7 and T10. Economics calculated revealed that T7 is highly economical and beneficial over T10 by gaining an amount of Rs. 660/-/acre/crop. Thus, treatment T7 containing N. muscorum (1.0 g), A. variahilis (1.0 g) and S. millei (1.0 g) + 50% NPK fertilizers can be recommended to sericulturists mainly to reduce the use of NPK fertilizers, by saving 50% of its cost and to improve soil fertility conditions, which in turn improves leaf yield and quality of mulberry.

The Relation of the Quality of Oriental Tobaccos to their Chemical Constituents I. Comparison of Quality and Chemical Properties of Leaf Tobacco Produced from Different Location and Season (환경요인에 따른 오리엔트종 잎담배의 화학적 특성과 품질과의 관계 I. 재배지역과 재배시기가 다른 잎담배의 품질과 화학성분 비교)

  • 류명현;손현주;조재성
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.33 no.1
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    • pp.87-96
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    • 1988
  • Some climatic factors and quality-ralated chemical properties were compared among conventional late and early transplanting in Korea, and conventional growing in Greece where climate for tobacco growth and quality is quite different from Korea. Precipitations were lowest and sunshine hours were highest for greece planting. Rainfall was 40% or less and the number of sunshine hours was higher by 20% or more in early transplanting than in conventional late planting during the period from 30 days to 80 days after transplanting in Korea. The content of total nitrogen, nicotine, petroleum ether extracts of leaves were much higher in Greece planting than those in Korea planting. The content of volatile organic acids and volatile neutrals were highest with Greece culture, followed by early and late transplanting in Korea. The leaf quality evaluated by price showed the same trends. Ash content and pH level of leaves were considerably lower in early transplanting than late planting. Petroleum ether extracts, volatile organic acids and total nitrogen showed significant positive correlation coefficients with assigned grade price, while ash content showed significant negative correlation coefficients. Quality indices were deviced and applied for the Quality evaluation.

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