• Title/Summary/Keyword: fibre characteristics

Search Result 100, Processing Time 0.034 seconds

Fundamental Study of Behavior on Steel·Concrete Composite Beam Reinforced Steel Fiber (강섬유를 보강한 강상판 합성보의 거동에 관한 기초적 연구)

  • Seo, Seung-Tag
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.11 no.2
    • /
    • pp.93-98
    • /
    • 2008
  • Steel fibre reinforced concrete (SFRC) were considered a new technology for the construction industry. However today this technology has found wider acceptance among the construction industry. Currently, steel fibres are used in varied segments in many application areas across different segments in the construction industry, especially in tunneling, airports, warehouses, etc. Time and safety are the main factors are among the various advantages which renders steel fibres superior to the competing product. For fibers reinforcing, The maximum load carrying capacity is controlled by fibers pulling out of the composite because fiber reinforcing does not have a deformed surface like larger steel reinforcing bars. The study demonstrated that above concept is applicable and effective in concrete structure by analytical study. The analytical result appears that SFRP have the potential to significantly increase the strength of existing concrete structures, while at the same time dramatically improving their fracture energy characteristics.

  • PDF

Studies on the Physico-chemical Components of Elephant-foot Produced in Korea (한국산 구약감자의 이화학적 성분조사)

  • Rhee, Seong-Kap
    • Journal of the Korean Society of Food Culture
    • /
    • v.10 no.5
    • /
    • pp.443-448
    • /
    • 1995
  • Korean fresh elephant-foot (Amorphophalus konjak K. Koch) and its powder were analyzed and compared with foreign samples to investigate the physico-chemical characteristics of Korean konjak. The Korean fresh konjak contained 80.6% of moisture content and most of the solid component comprises much of sugar, protein and trace of fat and fibre. The mannan content of Korean konjak powder is far smaller than those of Japanese and Chinese konjak powder. The analysis of the Korean konjak revealed that glutamic acid, aspartic acid and arginine included 45% of total amount, and other amino acid was incresaed with the order of valine, serine, leucine and glycine. The Korean konjak contained a moderate amount of K component and other inorganic component was larger with the order of P, Na and Ca. The yield of refined powder obtained from dried chip of Konjak was 61.0% in Korean one and 57.5% in Chinese one. The degree of lightness of Chinese konjak powder was slightly higher than that of Korean product, but the difference could not be recognized by naked eye.

  • PDF

STUDIES IN FIBRE DIGESTION AND PASSAGE RATE OF LIQUID AND SOLID IN CATTLE AND BUFFALOES

  • Abdullah, N.;Ho, Y.W.;Mahyuddin, M.;Jalaludin, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.4 no.2
    • /
    • pp.137-141
    • /
    • 1991
  • Rumen liquor characteristics and disappearance rate of dry matter were studied in Kedah-Kelantan cattle and swamp buffaloes fed grass of rice straw-based diet. Cobalt-EDTA and chromium mordented fibres prepared from the faecal material were used to determine the liquid and solid particles movement in both animal species fed with rice straw. Swamp buffaloes showed a more intense rumen fermentation activity than Kedah-Kelantan cattle when both species were fed straw-based diet. The buffaloes also demonstrated faster rates of grass and straw degradation in situ. The fluid outflow rate from the rumen of buffalo ($1.06{\pm}0.19l/h$) was observed to be slower than that of cattle ($1.55{\pm}0.01l/h$). No significant differences between cattle and buffaloes were observed in rumen fluid volume and passage rate of small particles from the rumen.

Effect of Operation Conditions on Permeation Characteristics of $CO_2$/$N_2$ through Polyethersulfone Hollow-Fibre Membranes (공정 조건에 따른 PES 중공사막의 이산화탄소/질소 분리 특성)

  • 신효진;이상윤;김정훈;장봉준;이수복;김범식;김진수;강득주
    • Proceedings of the Membrane Society of Korea Conference
    • /
    • 2004.05b
    • /
    • pp.89-93
    • /
    • 2004
  • 이산화탄소는 메탄, 오존, 산화질소, CFC등의 온실기체 중 약 50%를 차지하는 물질로서 이산화탄소 발생의 저감과 함께 회수 기술의 개발을 통한 배출량 억제는 환경적 측면에서 대단히 중요한 것으로 간주되고 있다. 따라서 각종 산업분야에서 발생하는 다양한 성분을 가진 다성분계 배가스내에 존재하는 10%내외의 이산화탄소만을 분리정제 농축하여 메탄, 메탄을 등의 다른 화학물질의 제조의 원료, 신에너지원, 고부가가치의 신제품 등으로 전환하는 연구가 활발히 진행 중이다.(중략)

  • PDF

Adaptation of impactor for the split Hopkinson pressure bar in characterizing concrete at medium strain rate

  • Zhao, Pengjun;Lok, Tat-Seng
    • Structural Engineering and Mechanics
    • /
    • v.19 no.6
    • /
    • pp.603-618
    • /
    • 2005
  • The split Hopkinson pressure bar (SHPB) technique is widely used to characterize the dynamic mechanical response of engineering materials at high strain rates. In this paper, attendant problems associated with testing 70 mm diameter concrete specimens are considered, analysed and resolved. An adaptation of a conventional solid circular striker bar, as a means of achieving reliable and repeatable SHPB tests, is then proposed. In the analysis, a pseudo one-dimensional model is used to analyse wave propagation in a non-uniform striker bar. The stress history of the incident wave is then obtained by using the finite difference method. Comparison was made between incident waves determined from the simplified model, finite element solution and experimental data. The results show that the simplified method is adequate for designing striker bar shapes to overcome difficulties commonly encountered in SHPB tests. Using two specifically designed striker bars, tests were conducted on 70 mm diameter steel fibre reinforced concrete specimens. The results are presented in the paper.

Bond between FRP formworks and concrete-effect of surface treatments and adhesives

  • Goyal, Reema;Mukherjee, Abhijit;Goyal, Shweta
    • Steel and Composite Structures
    • /
    • v.20 no.3
    • /
    • pp.671-692
    • /
    • 2016
  • FRP stay-in-place (SIP) formworks are designed as a support for casting concrete and as a tension reinforcement when concrete is cured. Bond development between SIP formwork and concrete is critical for FRP tension element to be effective. This paper reports the bond strength between FRP formwork and concrete for different interfacial treatments. A novel experimental setup is prepared for observing the bond behaviour. Three different adhesives with varying workability have been investigated. Along with the load-deformation characteristics, bond slip and strains in the formwork have been measured. A finite element numerical simulation was conducted for the experiments to understand the underlying mechanism. The results show that the adhesive bonding has the best bond strength.

Moistureproof Characteristics of Woodboard Types with Surface Thermal Changes (목질 보드류의 표면 열변화에 따른 접촉각(방습) 특성)

  • Shin, Sang-Ho;Liim, Nam-Gi
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2020.11a
    • /
    • pp.161-162
    • /
    • 2020
  • In this study, as part of securing related data, water droplets were dropped on the upper part of the wooden board for flooring in an environment such as floor heating, and the degree of absorption according to the surface temperature change was tested. The test results showed that the contact angle of the surface was low (25℃→40℃) or the droplet was absorbed into the small plate and disappeared. The contact angle of the OSB and MDF was decreased within 30 minutes, but the surface water droplet was maintained longer than the plywood. This is because the surface is coated with hydrophobicity unlike the plywood, but moisture absorption in the cross section after the second processing will not be prevented and it will lead to defect occurrence problem.

  • PDF

Chemical and Kinematic Properties of Sagittarius Stellar Streams

  • Kang, Gwibong;Lee, Young Sun;Kim, Young Kwang
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.46 no.2
    • /
    • pp.67.1-67.1
    • /
    • 2021
  • We use Sloan Digital Sky Survey, Large Sky Area Multi-Object Fibre Spectroscopic Telescope, and Apache Point Observatory Galactic Evolution Experiment data to analyze the kinematic and chemical properties of stellar members in Sagittarius(Sgr) tidal streams. Using distances, positions, proper motions, and angular momenta of stars around the Sgr streams, we gather clean sample of Sgr member stars. We find that the leading arm has different chemical, kinematic, orbital characteristics from those of the trailing arm and the remnant of Sgr. In particular, the leading arm shows relatively lower eccentricity distribution than the trailing arm, suggesting their origin may differ or they have experienced different dynamical evolution, which is in somewhat mystery.

  • PDF

Silkworm-food plant-interaction: search for an alternate food plant for tasar silkworm (Antheraea mylitta Drury) rearing

  • Deka, Manabendra;Gargi, Gargi;Kumar, Rajendra;Yadav, Harendra;Sahay, Alok
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.30 no.2
    • /
    • pp.58-63
    • /
    • 2015
  • An experimental rearing of tropical tasar silkworm, Antheraea mylitta Drury was conducted to study silkworm-food plant-interaction and thereby to search for an alternate silkworm food plant. The silkworm-food-plant-interaction was studied with six different food plant species viz. Terminalia tomentosa, Terminalia arjuna, Terminalia belerica, Terminalia chebula of Combretaceae family and Lagerstroemia speciosa, Lagerstroemia parviflora of Lythraceae family. The rearing performance of silkworm on Lagerstroemia speciosa in terms of cocoons per DFL and silk ratio was found comparable with Terminalia tomentosa and Termonalia arjuna, the primary tasar silkworm food plant species. These three plant species also possessed better results in terms of physiological (leaf moisture content and net photosynthesis rate) and biochemical (Chlorophyll, protein, carbohydrate and crude fibre contents) characteristics to support silkworm rearing than Terminalia belerica, Terminalia chebula and Lagerstroemia parviflora. The correlation study between silkworm rearing performance and food plant's constituents indicates commercial perspective of Lagerstroemia speciosa as an alternate food plant for tasar silkworm rearing.

The development of near infrared calibrations for assessing grass herbage quality

  • Sharma, Hss;Mellon, R.;Johnson, D.;Fletcher, H.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
    • /
    • 2001.06a
    • /
    • pp.1611-1611
    • /
    • 2001
  • The main selection parameters used by forage grass (rye and Italian rye grass) breeders are dry-matter yield, seasonal growth, persistency, disease resistance, heading date, and heading. These characteristics can all be identified usually in the segregating F2 population, however characteristics such as soluble carbohydrate level, protein, lipid and digestibility cannot be identified. The emphasis of this work is to introduce a quantitative selection process for characterization of herbage quality e.g. protein, water-soluble carbohydrates, fiber fractions, dry matter digestibility. NIRS calibrations are currently being developed for identifying grass genotypes to assist the selection process, thereby allowing the opportunity to actively breed improved herbage quality. The changes in fibre fractions, associated components and digestibility of a number of grass clones at different growth stages are being assessed changes taking place during a growing season. This will provide a database of the major changes taking place during a growing season. Attempts to classify quality differences between genotypes will be carried out using multivariate analysis of the spectral data. I addition changes associated with maturity of grass will be considered in order to develop robust calibrations.

  • PDF