• 한국생산제조학회지
• /
• 제21권4호
• /
• pp.619-624
• /
• 2012

In this study, MMT/fiber/polymer composites were fabricated by impregnating chopped strand glass mat into a vinylester resin mixed with clay. Tensile tests has been performed by using a universal testing machine to determine the effect of MMT addition on the tensile properties of MMT/chopped strand glass fiber/vinylester composites. And some pictures which are magnified cross section of breaking parts are has been taken by using a FE-SEM to confirm the behavior at breaking. The contents ratio of MMT applied in the composites were 0.5, 1.0, 1.5, and 2.0 wt% respectively. It has been found that the tensile strength and elastic modulus of MMT/chopped strand glass fiber/vinylester composites were improved at a proper content of MMT. Tensile strength and elastic modulus were maximized at a content of 1.0 wt% due to most effective dispersion of MMT. On the contrary, the failure strain was increased as MMT content was increased.

• Asian-Australasian Journal of Animal Sciences
• /
• 제6권4호
• /
• pp.509-514
• /
• 1993

The experiment was conducted to determine the effect of different fiber levels on milk production of crossbred Holstein milking cows fed urea-treated rice straw (UTS) as a roughage. Eight cows were allotted into 2 squares of 4 cows each with 4 treatments by a balanced design. The treatments were 17%, 22%, and 24% crude fiber (CF) diets and Thai feeding system (free choice of roughage and 1 kg of concentrates/2 kg of milk) as a control. Body weight change was not significantly different among the treatments during the experiment. Milk production (4% FCM) and milk protein content wee not different among the treatments, but milk fat content was low in the 17% CF group and high in the control group. Cows fed the 17% CF diet consumed less UTS and more concentrates than the others, and consequently total DM intake was not different among the treatments. The feed conversion ratio was significantly higher in the control. Feed cost per kg milk was lowest in the control and highest in the 17% CF diet. The fiber content of the diet would be more than 17%, preferably 22-24% for normally producing Thai crossbred Holstein cows when the UTS was fed as a main roughage source.

• Journal of the Korean Wood Science and Technology
• /
• 제25권2호
• /
• pp.33-44
• /
• 1997

This study was executed to examine the effects of polypropylene fiber length and process variables of the composites made from wood fiber and nonwood fiber mixed formulations. As a nonwood fiber the polypropylene with 3 denier thickness of tow condition was selected and cut into each length of 0.5, 1.0, 1.5, 2.0 and 2.5cm to mix with wood fiber. And also western hemlock wood fiber for medium density fiberboard was prepared. First, to decide an adequate polypropylene mixing fiber length, the composites of 1.0g/$cm^3$ density were made from 10% polypropylene fiber by each of five lengths and 90% western hemlock fiber mixed formulations. Thereafter as the experiments of process variable, the composites applied with adequate polypropylene fiber length(1.5cm) were made from 4 density levels (0.6, 0.8, 1.0, 1.2g/$cm^3$). 3 mixed formulations of wood fiber to polypropylene fiber(95 : 5, 90 : 10, 85 : 15), and 3 mat moisture contents(5, 10, 20%). According to the results and discussions it was concluded as follows ; The physical and mechanical properties were shown improved tendency. as polypropylene fiber length was increased in the range from 0.5 to 1.5cm, but shown decreasing tendency from 2.0 to 2.5 cm. Accordingly, it was shown that polypropylene fiber length is limited to 1.5cm or less length in mixing wood fiber and polypropylene fiber by turbulent air mixing process. As the densities of wood fiber-polypropylene fiber composites were increased, the physical and mechanical properties were clearly improved. Also they were shown significantly increasement statistically between densities respectively. In the mixed formulations, physical and mechanical properties were shown only slightly improvement, as they changed from 95 : 5 to 85 : 15 in wood fiber to polypropylene fiber. Despite of increasement of mat moisture content, mechanical properties were not improved significantly but physical properties were improved somewhat in wood fiber-polypropylene fiber composites.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2013년도 추계 학술논문 발표대회
• /
• pp.21-22
• /
• 2013

Nowadays, the fiber which mixed with concrete matrix always has low adhesion with cement paste. It's difficult to use fiber to reinforce the structure. For more adding fiber in concrete would cause some problems as the low flowability and surface polishing. Further study is needed in fiber using. In this research, further study in fiber reinforced concrete has been invested. Various fibers with different properties have been used to prevent cracking. Fiber reinforced concrete's fundamental properties as slump, air content, compressive strength and tensile strength have been tested. Optimum type of the fiber and optimum addition ratio of fiber has been invested to increase the utility of the fiber which used in concrete.

• KIEAE Journal
• /
• 제15권4호
• /
• pp.45-52
• /
• 2015

Purpose: Foam concrete is the concrete that contains large amount of air voids inside. In general, the density of foam concrete depends on parameters like water/binder ratio, foam volume, aggregate and pozzolan content, etc. Method: In this study, the effect of foam volume and fly ash content on dry density is investigated intensively in order to find the relationship between each parameter and their abilities to counteract with each other. According to the above information, though there are quite a number of studies on the effect micro fiber on foam concrete at low volume fractions, there is still lack of information especially on the high fiber content side. The objective of the second study is to investigate further on the use of micro fiber at higher volume fraction and fill in the lacking information. Beside from this study, the investigation of the effect of micro-fiber (polypropylene) to enhance the properties of foam concrete is also carried out. Result: Of the two variables that are investigated in this study, the foam volume and the fly ash content, show significant effect on the properties of foam concrete. The foam volume tends to decrease the density and strength of foam concrete. In the second part of our study, a large fibre volume fraction is proved to be able to evidently increase the flexural strength of foam concrete up to about 40% due to the effect of fibre bridging over the crack and a significant number of fibres that intercepts the crack surfaces. However, the compressive strength is found to decrease severely due to the occurrence of large pores as the result of fibre being added into concrete mixture.

• 한국식품영양학회지
• /
• 제32권4호
• /
• pp.328-334
• /
• 2019

The objective of this study was to analyze proximate composition, dietary fiber, mineral content, fatty acid composition in Cheonggak (Codium fragile) in order to encourage the consumption of Cheonggak. The proximate composition of Cheonggak was found to be 5.51% moisture, 24.09% crude ash, 15.79% crude protein, 2.47% crude lipid and 45.31% dietary fiber. The major mineral content of Cheonggak was Na 8,950 mg/100 g, Mg 1,252 mg/100 g, Ca 807 mg/100 g, K 457 mg/100 g, and trace mineral content was Fe 26 mg/100 g, Mn 8 mg/100 g, Zn 0.4 mg/100 g. Palmitic acid 36.86% and ${\alpha}$-linolenic acid 20.14% were the most contained fatty acids in Cheonggak. The ratio of saturated fatty acids to unsaturated fatty acids was 85.49% while ${\omega}-6$ fatty acids to ${\omega}-3$ fatty acids were 59.10%. Based on the proximate composition, dietary fiber, mineral content, and fatty acid composition, Cheonggak was judged to be a major source of dietary fiber and Mg and Ca, and it was deemed to be helpful in promoting health, including the prevention of hyperlipidemia. Cheonggak contained valuable nutrients similar to seaweed, which is produced and consumed the most in Korea. Thus, it is necessary to include Cheonggak in the food items.

• 한국작물학회지
• /
• 제39권4호
• /
• pp.373-381
• /
• 1994

호밀을 답리작으로 재배시 수량, 일반사료성분과 에너지 함량 및 수량을 질소시비량 및 예취시기에 따른 반응을 요약하면 다음과 같다. 1. 호밀은 질소시비량이 30kg/10a까지 많을수록 청예 및 건물수량이 증가하고 건물률은 감소하였으며 식물체의 엽신과 엽초의 비율은 증가하는 반면 줄기와 이삭의 비율은 감소하였다. 2. 호밀은 질소시비량이 많을수록 단백질, 총가소화양분(TDN), 무기물 및 에너지 함량과 수량이 모두 증가하였으며 ADF(acid detergent fiber) 와 NDF(neutral detergent fiber)의 함량은 감소하고 상대적사료가치가 높아졌다. 3. 질소시비량이 많아지면 예취시기가 늦더라도 전체 조단백질 함량 중에서 가급태 단백질이 차지하는 비율이 크게 낮아지지 않았다. 4. 호밀의 수확적기는 관행사료가치의 관점에서 는 대체로 유숙기 무렵으로 판단되었으나 사료의 에너지 관점에서는 이와 다소 차이가 있었다. 증체에너지(NEG)와 유지에너지(NEM) 면에서 본 수확적기는 개화후기에 높고 관행사료가치보다 10일정도 빨랐으며 에너지추정값(ENE)과 필유에너지(NEL)는 유숙기 무렵으로 같았다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
• /
• pp.315-322
• /
• 1997

This paper describes an experimental study on the seawater resistance of steel fiber reinforced concrete. The test method adopted for this study may be devided into long-term immersion test and accelerated test by wetting and drying. Test were carried out to evaluate the procedure in which reduction in dynamic modulus, length change and compressive strength to nine months were measured. Resistance indicators are the water - cement ratio, the content of steel fiber, the immersion water(artificial seawater or freshwater). The conditions of intervals of immersing in artificial seawater and drying, low water-cement ratio, and non-steel fiber became most deteriorated.

• 한국안전학회지
• /
• 제9권3호
• /
• pp.3-12
• /
• 1994

This study employed the Eshelby's equivalent inclusion method incorporated with mean field theory to investigate the Internal stress of short fiber-reinforced metal matrix composites during static loading and the dynamic finite element analysis by using alternative unit cell model to investigate the impact behaviors during the impact loading. Using the 2124 Al-SiC system as an example, the general effects of parameters such as fiber's aspect ratio, content and modulus were examined.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
• /
• pp.655-660
• /
• 2002

The purpose of this study is to analyze void ratio, coefficient of water permeability, and strength characteristics when silica fume and carbon fibers were added in order to improve the strength of porous concrete, and when recycled aggregates were used. Comparing with the case that recycled aggregate was not used, as the replacement ratio of recycled aggregate increased, the differences in void ratios and strength characteristics were decreased. In the case that silica fume was used, the content of 10% silica fume was most effective in improving strength. In the case that carbon fibers were used, the content of 3% carbon fiber were good to achieve the highest flexural strength, and Pan-derived CF was much better than pitch-derived CF in improving these effects.