• Title/Summary/Keyword: Materials characterization

Search Result 2,946, Processing Time 0.033 seconds

Effect of Groove Conditions on the Mechanical Properties of Welds Produced by the Combined Welding Process of Flux Cored Arc and Electro Gas in EH36 TMCP Steel Plate for Hull Structures (선체구조용 EH36 TMCP 후판의 FCAW 및 EGW 조합 용접부 기계적 성질에 미치는 개선조건의 영향)

  • Kim, Kihyuk;Kim, Kiwon;Sim, Hoseop;Bae, Kangho;Hong, Hyunuk;Park, Byunggyu
    • Journal of Welding and Joining
    • /
    • v.33 no.5
    • /
    • pp.35-40
    • /
    • 2015
  • Characterization of microstructures and mechanical properties of 83mm thickness EH36-TM welds produced by the combined flux cored arc (FCA) and electro gas (EG) welding processes has been studied with the two different groove conditions, single-V (SV) and double-V (DV) bevels. The welding consumables used for FCA and EG welding processes were ASME/AWS A5.29 (E81T1-K2) and A5.26 (EG72T), respectively. Experimental results showed that all the mechanical properties of welds such as tensile property, CVN toughness and Vickers hardness met IACS requirements. The tensile strength of EG welded plates were reduced by approximately 4% (DV: 3.8%, SV: 4.2%) compared to the base metal. The hardness value of SV-beveled weld metal was slightly lower than that of DV-beveled one. There were no significant differences as per welding groove conditions except for the weld metal. In addition, at the fusion line, the toughness of SV condition was 20J lower and the weld metal was 40J lower than DV condition, respectively. On the basis of microstructural analysis, grain boundary ferrite (GBF) structures for SV condition were 2 times higher volume fraction than for DV condition and their packet sizes were coarsened to almost double. It was thus suggested that the GBF volume fractions and packet sizes in the weld metal of EH36-TM steel plates are the most important factors affecting the mechanical properties of the combined FCA and EG welded joint. Nevertheless, all the results of welds with both DV and SV conditions were found to be excellent.

DETERMINATION OF MOISTURE AND NITROGEN ON UNDRIED FORAGES BY NEAR INFRARED REFLECTANCE SPECTROSCOPY(NIRS)

  • Cozzolino, D.;Labandera, M.;Inia La Estanzuela
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
    • /
    • 2001.06a
    • /
    • pp.1620-1620
    • /
    • 2001
  • Forages, both grazed and conserved, provide the basis of ruminant production systems throughout the world. More than 90 per cent of the feed energy consumed by herbivorous animals world - wide were provided by forages. With such world - wide dependence on forages, the economic and nutritional necessity of been able to characterize them in a meaningful way is vital. The characterization of forages for productive animals is becoming important for several reasons. Relative to conventional laboratory procedures, Near Infrared Reflectance Spectroscopy (NIRS) offers advantages of simplicity, speed, reduced chemical waste, and more cost-effective prediction of product functionality. NIR spectroscopy represents a radical departure from conventional analytical methods, in that entire sample of forage is characterized in terms of its absorption properties in the near infrared region, rather than separate subsamples being treated with various chemicals to isolate specific components. This forces the analyst to abandon his/her traditional narrow focus on the sample (one analyte at a time) and to take a broader view of the relationship between components within the sample and between the sample and the population from which it comes. forage is usually analysed by NIRS in dry and ground presentation. Initial success of NIRS analysis of coarse forages suggest a need to better understand the potential for analysis of minimally processed samples. Preparation costs and possible compositional alterations could be reduced by samples presented to the instrument in undried and unground conditions. NIRS has gained widespread acceptance for the analysis of forage quality constituents on dry material, however little attention has been given to the use of NIRS for chemical determinations on undried and unground forages. Relatively few works reported the use of NIRS to determine quality parameters on undried materials, most of them on both grass and corn silage. Only two works have been found on the determination of quality parameters on fresh forages. The objectives of this paper were (1) to evaluate the use of NIRS for determination of nitrogen and moisture on undried and unground forage samples and (2) to explore two mathematical treatments and two NIR regions to predict chemical parameters on fresh forage. Four hundred forage samples (n: 400) were analysed in a NIRS 6500 instrument (NIR Systems, PA, USA) in reflectance mode. Two mathematical treatments were applied: 1,4,4,1 and 2,5,5,2. Predictive equations were developed using modified partial least squares (MPLS) with internal cross - validation. Coefficient of determination in calibration (${R^2}_{CAL}$) and standard error in cross-validation (SECV) for moisture were 0.92 (12.4) and 0.92 (12.4) for 1,4,4,1 and 2,5,5,2 respectively, on g $kg^{-1}$ dry weight. For crude protein NIRS calibration statistics yield a (${R^2}_{CAL}$) and (SECV) of 0.85 (19.8) and 0.85 (19.6) for 1,4,4,1 and 2,5,5,2 respectively, on a dry weight. It was concluded that NIRS is a suitable method to predict moisture and nitrogen on fresh forage without samples preparation.

  • PDF

A Study on Vitalization Methods of Local Cultural Contents in the Public Libraries (공공도서관에서의 향토문화콘텐츠 활성화 방안에 관한 연구)

  • Noh, Younghee;Kang, Jung-Ah
    • Journal of Korean Library and Information Science Society
    • /
    • v.45 no.4
    • /
    • pp.67-93
    • /
    • 2014
  • This study aims to present a direction for local libraries on how to collect folk culture content and provide services in cooperation with public libraries across the country, with a focus on public libraries, in implementing the government policy to collect, classify, store, research, and utilize folk culture content. Results of the study drawn from literature review, surveys, case-studies are as follows: First, based on the advantage of higher accessibility than other institutions in charge of folk culture content provision, libraries should take a role to collect, store, and utilize folk culture content for public purpose of improving knowledge and interests of residents and storing local history. Second, folk culture content collection, enhanced content-creating, and user-oriented services reflecting various demands should be expanded, seeking ways to improve management conditions of folk culture content based on collaboration network between libraries, along with drawing interests and support from the local government and the central government. Thirdly, libraries should provide expanded services of collection, creation, use of folk culture content with a focus on local culture through regular and systematic study and building of folk culture content.

Preparation and Characterization of the Hydrolyzed Protein from Shaving Scraps of Leather Waste Containing Chromium (피혁폐기물(皮革廢棄物)인 Shaving scraps으로 부터 가수분해(加水分解) 단백질(蛋白質)의 제조(製造) 및 특성(特性))

  • Kim, Won-Ju;Cho, Ju-Sik;Lee, Hong-Jae;Heo, Jong-Soo
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.5 no.2
    • /
    • pp.47-56
    • /
    • 1997
  • To examine of possibility protein recycling of shaving scraps contained chrome generated from manufacturing process of leather, the characteristics of hydrolyzed protein that differently treated with MgO as alkaline agent were investigated. In alkaline hydrolysis of saving scraps treated with MgO, MgO had to be treated over 5.0% to maintain over pH 8.0 that is insoluble of chrome. Under the condition of alkaline treated with MgO, the solubility of chrome is low with about 60%. The average molecular weight of hydrolyzed proteins from shaving scraps treated with MgO was about 80~100 KD. The amino acid contents of that were largely collagen proteins such as glycine, alanine and proline, and acidic amino acids such as aspartic acid and glutatamic acid. The contents of Mg, Ca and Na in hydrolyzed protein were too much as liquid fertilizer, and chrome contents was 30~40 ppm that largely decreased in comparing with raw materials (40,000~42,000 ppm).

  • PDF

Analysis of High Radioactive Materials in Irradiated DUPIC SIMFUEL Using EPMA (EPMA를 이용한 DUPIC 사용후 핵연료 핵분열 생성물의 특성 분석)

  • 정양홍;유병옥;주용선;이종원;정인하;김명한
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.2 no.2
    • /
    • pp.125-133
    • /
    • 2004
  • Fission products of DUPIC (Direct Use of Spent PWR Fuel in CANDU Reactors) fuel, irradiated in HANARO research reactor with 61 ㎾/m of maximum linear power and 1,770 ㎿d/tU of average burn-up, was characterized by EPMA(Electron Probe Micro Analyzer). In order to find accurate characterization, the analysis results by EPMA of fresh simulated DUPIC fuel containing fission products as chemicals were compared with that of wet chemical analysis. The metallic precipitates observed at the center of the fresh simulated DUPIC fuel were about 1 $\mu\textrm{m}$ in size and their major components by EPMA were Mo-53.89 at.%, Ru-37.40 at.%, and Pd+Rh-8.71 at.%. Established procedure through the fresh simulated DUPIC fuel was applied to the irradiated DUPIC fuel. Observed size of metallic precipitates were 2∼2.5 $\mu\textrm{m}$ and their compositions were Mo-47.34 at.%, Ru-46 at.%, and Pd+Rh-6.65 at.%. What are uncommon things for this experiment, special treatment for improving the conductivity was attempted to the specimen and the conditions of exact irradiation of electron beam to small metallic precipitate were suggested.

  • PDF

Characterization of PET films coated with organic-inorganic hybrid coating system containing surface modified zirconia (표면 개질된 지르코니아를 함유한 유-무기 하이브리드 코팅액으로 도포된 PET 필름의 특성)

  • Lee, Soo;Kim, Sang Yup;Kim, Young Jun
    • Journal of the Korean Applied Science and Technology
    • /
    • v.35 no.3
    • /
    • pp.595-605
    • /
    • 2018
  • In recent years, researches on organic-inorganic coating films have conducted a nanocomposite system composed of organic resin matrices having excellent flexibility and chemical stability and inorganic materials having excellent mechanical properties. The o-phenylphenoxyethyl acrylate (OPPEA) used as the acrylate monomer has a high refractive index of 1.58, and the bisphenol A ethoxylate diacrylate (BAEDA) has a low refractive index but improves the chemical stability of the organic resin. In addition, zirconia used as an inorganic material exhibits excellent durability and optical properties. In this study, the BAEDA contents in acrylate monomer were controlled to produce a film with suitable optical transparency. And optimum conditions were established by comparing the changes in surface properties of PET films detected with pencil hardness tester, Abbe's refractometer, and UV-vis spectrophotometer. The hydrophobicity and the dispersibility of zirconia in acrylate monomer were much improved after modification with ${\gamma}$-methacryloxypropyltrimethoxysilane (MPS), which is a silane coupling agent. And the existence of ester C=O bond peak at $1716cm^{-1}$ introduced by MPS through FT-IR ATR spectrophotometer confirmed the completion of surface modification of zirconia with MPS. In addition, the presence of silicon atom on the surface modified zirconia was also proved using X-ray fluorescence spectrometer. When the photocurable hybrid coating was prepared by introducing chemically modified zirconia into acrylate monomer, the refractive index of this coated PET film was improved by 1.2%, compared to the only acrylate coated PET film. The homogeneous distribution of zirconia in acrylate coating layer on PET film was also identified through SEM/EDS mapping analysis technique.

Preparation and characterization of protein isolate from Yellowfin tuna Thunnus albacares roe by isoelectric solubilization/precipitation process

  • Lee, Hyun Ji;Lee, Gyoon-Woo;Yoon, In Seong;Park, Sung Hwan;Park, Sun Young;Kim, Jin-Soo;Heu, Min Soo
    • Fisheries and Aquatic Sciences
    • /
    • v.19 no.3
    • /
    • pp.14.1-14.10
    • /
    • 2016
  • Isoelectric solubilization/precipitation (ISP) processing allows selective, pH-induced water solubility of proteins with concurrent separation of lipids and removal of materials not intended for human consumption such as bone, scales, skin, etc. Recovered proteins retain functional properties and nutritional value. Four roe protein isolates (RPIs) from yellowfin tuna roe were prepared under different solubilization and precipitation condition (pH 11/4.5, pH 11/5.5, pH 12/4.5 and pH 12/5.5). RPIs contained 2.3-5.0 % moisture, 79.1-87.8 % protein, 5.6-7. 4 % lipid and 3.0-3.8 % ash. Protein content of RPI-1 and RPI-2 precipitated at pH 4.5 and 5.5 after alkaline solubilization at pH 11, was higher than those of RPI-3 and RPI-4 after alkaline solubilization at pH 12 (P < 0.05). Lipid content (5.6-7.4 %) of RPIs was lower than that of freeze-dried concentrate (10.6 %). And leucine and lysine of RPIs were the most abundant amino acids (8.8-9.4 and 8.5-8.9 g/100 g protein, respectively). S, Na, P, K as minerals were the major elements in RPIs. SDS-PAGE of RPIs showed bands at 100, 45, 25 and 15 K. Moisture and protein contents of process water as a 2'nd byproduct were 98.9-99.0 and 1.3-1.8 %, respectively. Therefore, yellowfin tuna roe isolate could be a promising source of valuable nutrients for human food and animal feeds.

Characterization of Hydrogel Tinted Contact Lens Containing 4-iodoaniline using Titanium Silicon Oxide Nanoparticles as Additive (티타늄 실리콘 옥사이드 나노입자를 첨가제로 사용한 4-iodoaniline을 포함한 하이드로젤 착색 콘택트렌즈의 특성)

  • Cho, Seon-Ahr;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.19 no.3
    • /
    • pp.315-322
    • /
    • 2014
  • Purpose: The physical and optical characteristics of hydrophilic tinted contact lens containing titanium silicon oxide nanoparticles and the basic hydrogel contact lens material containing 4-iodoaniline were examined. In this study, the utility of titanium silicon oxide nanoparticles as a UV-blocking material for ophthalmologic devices were investigated by measuring the UV transmittance of the produced polymer. Also, titanium silicon oxide nanoparticles only without the addition of 4-iodoaniline in primary contact lens materials by copolymerizing two groups were compared. Methods: For manufacturing hydrogel lens, HEMA, MA, MMA, 4-iodoaniline and a cross-linker EGDMA were copolymerized in the presence of AIBN as an initiator. Also, the titanium silicon oxide nanoparticles was used as additive. After polymerization the physical properties such as water content, refractive index, contact angle and spectral transmittance of produced contact lenses were measured. Results: Measurement of the physical properties of the copolymerized material showed that the water content, refractive index, UV-B transmittance and contact angle were in the range of 35.01~38.60%, 1.4350~1.4418, $34.15{\sim}57.25^{\circ}$ and 1.0~10.0%, respectively. Titanium silicon oxide nanoparticles is not used as an additive in the experimental group, the results of the measurement showed that the water content, refractive index, contan angle and UV-B transmittance of the hydrogel lens polymer was 34.00~36.80%, 1.4378~1.4420, $40.15{\sim}60.16^{\circ}$ and 1.8~25.0%, respectively. Conclusions: Also, the transmittance for UV light was reduced significantly in combinations containing titanium oxide nanoparticles.

A Study on Improvement of Fire-resistant and Flame-retardant Properties of Silicone Rubber Composites Containing Perlite (펄라이트를 첨가한 실리콘 고무 복합체의 내화 및 난연 특성 향상에 관한 연구)

  • Lee, Byung-Gab;Lee, Jong-Hyeok;Bang, Dae-Suk;Won, Jong-Pil;Jang, Il-Young;Park, Woo-Young;Jhee, Kwang-Hwan
    • Elastomers and Composites
    • /
    • v.46 no.2
    • /
    • pp.164-170
    • /
    • 2011
  • In this study, silicone rubber filled with environmentally-friendly perlite was prepared by mechanical mixing in order to improve thermal properties, such as heat and fire resistances. We found that the properties of silicone rubber composites depended on perlite concentration by various characterization methods. Thermogravimetric analysis(TGA) indicated that the initial degradation temperature of silicone/perlite composite was higher than that of pristine silicone rubber. The gas torch test showed that the opposite side temperature of composite materials was remarkably low as compared to that of pristine silicone rubber. In addition, the composites containing 5 wt% and 10 wt% of perlite showed remarkable thermal stability at elevated temperatures according to the results of both fireproof furnace tests under the RABT condition and carbonization furnace tests. The images from a scanning electron microscope(SEM) showed the degree of dispersion of perlite in silicone rubber. Finally, it was confirmed that limited oxygen index(LOI) was increased with perlite concentration.

Preparation and Characterization of Hyaluronic Acid Loaded PLGA Scaffold by Emulsion Freeze-Drying Method (히알루론산을 함유한 PLGA 지지체의 제조 및 특성결정)

  • Ko, Youn-Kyung;Kim, Soon-Hee;Jeong, Jae-Soo;Park, Jung-Soo;Lim, Ji-Ye;Kim, Moon-Suk;Lee, Hae-Bang;Khang, Gil-Son
    • Polymer(Korea)
    • /
    • v.31 no.6
    • /
    • pp.505-511
    • /
    • 2007
  • Poly(lactide-co-glycolide)(PLGA) and hyaluronic acid (HA) has been widely used as biocompatible scaffold materials to regenerate tissue. In this present study, we fabricated microporous PLGA and HA loaded PLGA scaffolds by a emusion freeze-drying method. In order to confirm that the release profile of cytokine or water-soluble drugs, we manufactured the granulocyte macrophage colony stimulating factor(GM-CSF) loaded PLGA and HA-PLGA scaffold. All scaffolds were characterized using scanning electron microscope(SEM), mercury porosimeter and wettability measurement. Cell proliferation and viability were assessed by a 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) test. The porosity of HA-PLGA scaffold was greater than 95% with the total pore area of $261\;m^2/g$. The HA-FLGA scaffold exhibited well interconnected pores to allow greater cell adhesion and prolixferation. It was proven by higher cell viability in the HA-PLGA scaffold than PLGA alone. This may be due to the enhanced natural properties and higher water retention capacity of HA.