• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.5
• /
• pp.755-762
• /
• 2018

Objective: The objective of the study was to determine the influence of varying fibrous diets on fecal characteristics of growing pigs. Methods: A total of 104 pigs (initial weight $18{\pm}2.0kg$) were used in the study. They were housed in individual pens and fed on diets containing maize cob, grass hay, lucerne hay, maize stover, and sunflower husk. These fibers were included at 0, 80, 160, 240, 320 and 400 g/kg. Fecal and urine samples were collected. Results: Fecal output was largest amongst pigs fed on diets containing grass hay and maize stover (p<0.05). Nitrogen content was highest in feces from pigs fed on sunflower husk (p<0.05). Pigs fed on diets containing maize stover and maize cobs produced the largest concentrations of short chain fatty acids. Acetate concentration was high in feces of pigs fed maize stover than those fed grass hay and lucerne hay (p<0.05). As the level of fiber inclusion increased, fecal consistency and nitrogen content increased linearly (p<0.05). Urea nitrogen decreased as the inclusion level increased across all the fibers (p<0.05), with maize cobs containing the largest content of urea nitrogen. As dietary fiber content increased, fecal nitrogen content also increased (p<0.05). Conclusion: It was concluded that different fiber sources influence fecal characteristics, thereby having different implications on pig waste management. It is vital to monitor fiber inclusion thresholds so as to easily manage environmental pollutants such as butyrate that contribute to odors.

• Journal of Nutrition and Health
• /
• v.28 no.1
• /
• pp.5-14
• /
• 1995

The present study was performed to investigate the effect of cereal fiber on lipid concentration of liver and serum in rats. Male Sprague-Dawley rats weighing 180$\pm$4g were divided into five groups by completely randomized block design : R, BR, B, W, and F. Each group fed a diet containing 0.7% cholesterol and a kind of cereal among rice(R), brown rice(BR), barley(B), whole wheat(W), and wheat flour(F) for 5 weeks. The results were summarized as follow : 1) Food intake. weight gain and feed efficiency ratio were not significantly different among the groups. 2) Fecal wet weight and dry weight were significantly higher in W group which fed the most amount of IDF(insoluble dietary fiber). 3) The weight of large intestine was significantly heavier in the W group compared to the others. But the weights of liver, stomach and small intestine were not significantly different among the groups. 4) Total lipid. triglyceride(TG) and total cholesterol(TC) content in liver were significantly different among the groups. The values were the lowest in the B group whose intake of SDF(soluble dietary fiber) was the highest 5) TC content in serum was not significantly different among the groups. TG content in serum was significantly lower in the rest groups than in the R group. HDL-c and free-c content in serum were significantly higher in the B group than in the rest groups. HDL-c/LDL-c, free-c/ester-c ratio were the highest in the B group but not significant. Above results show that the dietary fiber contained in cereals has physiological effects and they are different depending on fractions, IDF and SDF.

• KIEAE Journal
• /
• v.15 no.4
• /
• 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.

• International Journal of Concrete Structures and Materials
• /
• v.8 no.4
• /
• pp.279-287
• /
• 2014

This paper presents the findings of an investigation of the fiber content variations in concrete being discharged from a ready-mix truck at the construction site. Concrete samples were extracted from the truck drums at the beginning, middle and end of discharge. Subsequently, fibers in each sample were separated from the concrete, and weighed. Presumably, synthetic macro fibers will float towards the top, i.e. towards the drum opening, of the inclined, revolving truck-drum, while, on the other hand, steel fibers will tend to gravitate towards the lower parts of the mixer drum. Accordingly, the discharge batch, containing synthetic macro fibers, will contain a higher amount of synthetic fibers per unit volume at the start of discharge than the average unit volume fiber content of the mix, and the content will gradually decrease further down the batch. The discharge batch of steel fiber concrete will contain fewer fibers per unit volume at the start of discharge than the average unit volume fiber content of the mix, and the content should gradually increase further down the batch. The correctness of the foregoing is partly confirmed. A certain percentage of the truck loads did not comply with the proposed requirements, mainly steel fiber reinforced batches, indicating the necessity of a code or guideline amendment. A change in the Norwegian shotcrete directive was made in 2011, based upon experimental research work (2010), which, in combination with the subsequent University of Life Sciences report (2012), constitutes the foundation of this article.

• The Korean Journal of Food And Nutrition
• /
• v.32 no.4
• /
• 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.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.4 no.2
• /
• pp.157-167
• /
• 1994

This study was conducted to analyze the relationship between the types of fiber and its content and the levels of airborne fiber concentrations at eight parking lots where sprayed insulation material was found on the walls and ceilings. Also this study was designed to find the relationship between the levels of airborne fiber concentrations and such variables as air current, humidity, total exhaust volume, surface condition of insulation material and building age. The results obtained were as follows : 1. No significant correlation was found between the levels of airborne tiber concentration and the building age, air current, humidity, total exhaust volume, space and the number of traffics. 2. A significant correlation was found between the levels of airborne fiber concentration and the MMMF content of the insulation material(r=0.7594). However, no significant correlation was found between the levels of airborne fiber concentration and total fiber content of insulation material. 3. The differences of the airborne fiber concentrations among Cateogory 1, 2 and 3 classified by the degrees of surface insulation material maintenance were very significant. 4. Two bulk samples contained 30% crodicolite and 1% anthophylite. The MMMFs, in all parking lots, included mineral wool, cellulose fiber, trace cellulose fiber, trace tiber glass and vermiculite. 5. The mean value and the range of airborne fiber concentrations at 8 parking lots were $0.0239{\pm}0.0095f/cc$ and 0.0054-0.0447 f/cc, respectively. The fiber concentrations of 35 out of 38 samples(92%) were over 0.01 f/cc which is the Environment Administration's recommended asbestos level for the underground space. This study suggests that most of building insulation materials used in Korea, contain MMMF and sometimes asbestos. Currently, MMMF pollution levels may exceed the Environment Administration's recommended level for underground space. It has been found that airborne fiber concentrations increased significantly with MMMF content and with the maintenance condition of surface material. Therefore, it is recommended that a proper management technique should be developed and immediately implemented since the conditions of surface material will be gradually deteriorated due to building age and usage. Since health hazards of the MMMF, similar to those of asbestos, are being gradually acknowledged, a proper management technique which is applicable to control total airborne fiber concentrations, both asbestos and MMMF, be developed and an acceptable indoor air standard be promulgated as early as possible.

• Journal of Adhesion and Interface
• /
• v.19 no.2
• /
• pp.60-67
• /
• 2018

In the present study, when the surface of kenaf, which is an environmentally friendly natural fiber, was treated by using adhesive solution containing Chemlok 402, the effects of fiber surface treatment, fiber content and fiber length on the cure characteristics, hardness, tensile modulus and abrasion resistance of kenaf/natural rubber composites were investigated. The kenaf fiber contents consisting of the composites were varied with 0, 5, 10, 15, and 29 phr at a fixed fiber length of 2 mm and also the fiber length was varied with 2, 35, and 70 mm at a fixed fiber content of 5 phr. The Tmax and tc90 values, Shore A hardness, tensile modulus, and abrasion resistance of natural rubber composites strongly depended on the kenaf fiber content and length. The characteristics of the composite with kenaf fibers treated with the adhesive solution containing Chemlok 402 were higher than those untreated. This is ascribed to the improved interfacial adhesion between the treated kenaf fiber and the rubber matrix. This study suggests that an appropriate use of adhesive solution may be possible to increase the properties of natural fiber-reinforced composites.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.20 no.5
• /
• pp.620-632
• /
• 2017

A chemical vapor curing method(CVC) was developed to cure polycarbosilane(PCS) fibers by using cyclohexene vapour as a non-oxygen active reactant, instead of air in oder to prepare the silicon carbide(SiC) fiber with low oxygen content. A cross-linked PCS fibers by cyclohexene vapor showed a completely different variation in IR spectra in comparison to the air-cured PCS fiber. CVC method resulted in less than 3 wt% in oxygen content. In this experiment conditions, The average tensile strength and modulus of SiC fiber obtained by CVC had 1995 MPa and 183 GPa respectively, which is higher than that of SiC fiber prepared by air-curing process.

• Journal of the Korean Ceramic Society
• /
• v.56 no.5
• /
• pp.513-520
• /
• 2019

This study reports the improvement of mechanical properties of Al₂O₃ porous ceramics from colloidal suspension with the addition of carbon fiber by direct foaming. The initial colloidal suspension of Al₂O₃ was partially hydrophobized by surfactant to stabilize wet foam with the addition of carbon fiber from 2 to 8 wt% as stabilizer. The influence of carbon fiber on the air content, bubble size, pore size and pore distribution in terms of wet foam stability and physical properties of porous ceramics were discussed. The viscosity of the colloidal suspension was increased giving solid like properties with the increased in carbon fiber content. The mechanical properties of the sintered porous samples were investigated by Hertzian indentation test. The results show the wet foam stability of more than 90% corresponds to compressive loading of 156.48 N and elastic modulus of 57.44 MPa of sintered sample with 8 wt% of carbon fiber content.

• Geomechanics and Engineering
• /
• v.30 no.5
• /
• pp.461-469
• /
• 2022

One of the most important factors that should be considered for using any ground improvement technique is the stability of stabilized soil and the durability of the provided solution for getting the required engineering properties. Generally, most of the earth structures that are constructed on clayey soils are exposing movements due to the long periods of drying or wetting cycles. Over time, environmental changes may result in swells or settlements for these structures. In order to mitigate this problem, this research has been performed on mixtures of high plasticity clay with traditional additives such as lime, cement and non-traditional additives such as polypropylene fiber. The purpose of the research is to assess the most appropriate ground improvement technique by using commercially available additives for resisting the developed desiccation cracks during the drying process and resisting the volume changes that may result during wet/dry cycles as an attempt to simulate the changes of environmental conditions. The results show that the fiber-reinforced samples have the lowest volumetric deformation in comparision with cement and lime stabilized samples, and the optimum fiber content is identified as 0.38%. In addition, the desiccation cracks were not visible on the samples' surface for both unreinforced and chemically stabilized samples. Regarding cracks resistance resulting from the desiccation process, it is observed, that the resistance is connected with the fiber content and increases with the increase of the fiber inclusion, and the optimum content is between 1% and 1.5%.