• Advances in concrete construction
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• 제15권6호
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• pp.431-444
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• 2023

This study investigated the use of latex-modified sand concrete reinforced with sisal fibers (LMSC) as a repair material. Notably, no prior research has explored the application of LMSC for this purpose. This paper examines the interface bond strength and the type of failure between LMSC as a repair material and the normal concrete (NC) substrate utilising four different surfaces: without surface preparation as a reference (SR), hand hammer (HA), sandblasted (SB), and grooved (GR). The bond strength was measured by bi-surface shear, splitting tensile, and pull-off strength tests at 7, 28, and 90 days. Scanning electron microscopy analysis was also performed to study the microstructure of the interface between the normal concrete substrate and the latex-modified sand concrete reinforced with sisal fibers. The results of this study indicate that LMSC has bonding strength with NC, especially for HR and SB surfaces with high roughness. Therefore, substrate NC surface roughness is essential in increasing the bonding strength and adhesion. Eventually, The LMSC has the potential to repair and rehabilitate concrete structures.

• Structural Engineering and Mechanics
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• 제87권6호
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• pp.615-624
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• 2023

The focus of this study is on the structural behaviour of reinforced concrete beams in which basalt fiber and SBR latex were added and the cement was partially replaced with 10% of hypo sludge. Eight different mixes of reinforced beam specimens were tested under static loading behaviour. The experiments showed, the structural behaviour with features such as load-deflection relationships, crack pattern, crack propagation, number of crack, crack spacing and moment curvature. A stress-strain relationship to represent the overall behavior of reinforced concrete in tension, which includes the combined effects of cracking and mode of failure along the reinforcement, is proposed. The structural behaviour results of reinforced concrete beams with various types of mix were tested at the age of 28 days. The investigation revealed that the flexural behaviors of hypo sludge reinforced concrete beams with addition of basalt fiber and SBR latex was higher than that of control concrete reinforced beam. The specimen (LHSBFC) with 10% hypo sludge, 0.25% Basalt fiber and 10% SBR latex showed an increase of 5.08% load carrying capacity, 7.6% stiffness, 3.97% ductility, 31.29% energy dissipation when compared to the control concrete beam. The analytical investigation using FEM shows that it was in good agreement with the experimental investigation.

• Composites Research
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• 제20권2호
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• pp.32-38
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• 2007

Natural fibers can refer to all types of fibres only produced by nature. Their lengths vary from particles to long strands. Natural fibers are categorized roughly by six types, depending on the types of sources; base, leaf, seed, grasses, fruit and wood. Of these fibers, jute, flax, sisal and ramie are the most commonly used as reinforced materials in preparing polymer composites. In development and improvement of these composites, many studies have been implemented to overcome the drawbacks such as incompatibility, moisture problems and so on. The range of industry sectors of natural fiber-reinforced polymer composites becomes more extensive gradually and many of the companies all over the world are engaged in fabrications or applications. This paper mainly discussed the recent status of the domestic/overseas market and research issues of natural fiber-reinforced polymer composites. We made an exception of wood-polymer composites market which have played a great role because they had been often dealt with.

• Geomechanics and Engineering
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• 제33권4호
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• pp.401-414
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• 2023

Organic clays are ideal habitat for flora and fauna. From a geotechnical perspective, organic clays are soft, weak, variable, heterogeneous and flocculated. Portland cement is a universally common stabiliser. However, some organic acids in soil inhibit full hydration and expose cementation products to rapid dissolution. This paper investigates scopes for use of C₃S cement to enable durable cementation. Prospects of using PP fibre alongside with C₃S cement, scopes for partial replacement of C₃S cement with a plant-based nanosilica and evolution of binders are then investigated. Binding mixtures here mimic the natural functions of rhizoliths, amorphous phases, and calcites. Testing sample population include natural and fibre-reinforced clays, compact mixes of clay - C₃S cement, clay - nanobiosilica, and clay, C₃S cement and nanobiosilica. Benefits and constraints of C₃S cement and fibres for retaining the naturally flocculated structure of organic clays are discussed. Nanobiosilica provides an opportunity to cut the C₃S content, and to transition of highly compressive organic clays into an engineered, open-structured medium with >0.5 MPa compressive strength across the strains spanning from peak to 1.5-times peak.

• Preventive Nutrition and Food Science
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• 제7권3호
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• pp.332-345
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• 2002

It is a recent observation that about 80 per cent of the body's immune system is localized in the gastrointestinal tract. This explains to a large extent why eating right is important for the modulation the immune response and prevention of disease. In addition it is increasingly recognized that the body has an important digestive system also in the lower gastrointestinal tract where numerous important substances are released by microbial enzymes and absorbed. Among these substances are short chain fatty acids, amino acids, various carbohydrates, poly-amines, growth factors, coagulation factors, and many thousands of antioxidants, not only traditional vitamins but numerous flavonoids, carotenoids and similar plant- and vegetable produced antioxidants. Also consumption of health-promoting bacteria (probiotics) and vegetable fibres (prebiotics) from numerous sources are known to have strong health-promoting influence. It has been calculated that the intestine harbours about 300,000 genes, which is much more than the calculated about 60,000 for the rest of the human body, indicating a till today totally unexpected metabolic activity in this part of the GI tract. There are seemingly several times more active enzymes in the intestine than in the rest of the body, ready to release hundred thousand or more of substances important for our health and well-being. In addition do the microbial cells produce signal molecules similar to cytokines but called bacteriokines and nitric oxide, with provide modulatory effects both on the mucosal cells, the mucosa- associated lymphoid system (MALT) and the rest of the immune system. Identification of various fermentation products, and often referred to as synbiotics, studies of their role in maintaining health and well-being should be a priority issue during the years to come.

• 패션비즈니스
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• 제14권2호
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• pp.138-150
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• 2010

In the dyeing of cotton and silk fibres using Caesalpinia sappan, the effects of pH changes of the Caesalpinia sappan dye liquor on the color were examined. In order to adjust the pH of the Caesalpinia sappan dye liquor, Schisandra chinensis extract and carboxylic acid were used for acidic condition, lye and the NaOH aqueous solution were used for alkaline condition. By introducing the dyeing method of pH adjustment, firstly, the effect on the reddish color inherent to the Caesalpinia sappan was examined. At the same time, the manifestation of the yellow color, which affect the manifestation of the red color greatly, was examined in detail quantitatively. By dyeing the cotton and silk fabrics, the inherent relationships established between the pH hanges and the fibre characteristics were sought to be examined.

• Asian-Australasian Journal of Animal Sciences
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• 제3권4호
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• pp.305-312
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• 1990

The seasonal changes in production, the systems of management and the seasonal climatic and feeding conditions are described for three farms representative of the major areas for growing fine-wool sheep in northern China. At all farms, summer and autumn were seasons of rapid liveweight gain and wool growth. In the winter and spring, during lactation, liveweight declined wool growth decreased by approximately 70%, and fibre diameter by 4 to 8 microns. The wool produced was characterized by a very low clean wool yield (39-51%). Greasy fleece weights ranged from 4.5 to 8.0 kg and average diameter of wool fibres from 20.5 to 23 microns. The number of lambs born per 100 ewes mated ranged from 79 to 95, lamb weights ranged from 3.8 to 4.5 kg, and weaning weights ranged from 17 to 25 kg. Overall, the patterns of sheep production were similar to those found in seasonally arid environments (such as in the mediterranean climatic zone). Yield of clean wool and therefore clean fleece weights were far below those in most other fine-wool producing areas of the world.

• Advances in aircraft and spacecraft science
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• 제4권6호
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• pp.729-744
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• 2017

This investigation highlights rationale of electrically conductive nano adhesives for its essential application for Electromagnetic Interference (EMI) Shielding in satellites and Lightning Strike Protection in aircrafts. Carbon Nano Fibres (CNF) were functionalized by electroless process using Tollen's reagent and by Plasma Enhanced Chemical Vapour Deposition (PECVD) process by depositing silver on CNF. Different weight percentage of CNF and silver coated CNF were reinforced into the epoxy resin hardener system. Scanning Electron Microscopy (SEM) micrographs clearly show the presence of CNF in the epoxy matrix, thus giving enough evidence to show that dispersion is uniform. Transmission Electron Microscopy (TEM) studies reveal that there is uniform deposition of silver on CNF resulting in significant improvement in interfacial adhesion with epoxy matrix. There is a considerable increase in thermal stability of the conductive nano adhesive demonstrated by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Four probe conductivity meters clearly shows a substantial increase in the electrical conductivity of silver coated CNF-epoxy composite compared to non-coated CNF-epoxy composite. Tensile test results clearly show that there is a significant increase in the tensile strength of silver coated CNF-composites compared to non-coated CNF-epoxy composites. Consequently, this technology is highly desirable for satellites and EMI Shielding and will open a new dimension in space research.

• Journal of the Korean Wood Science and Technology
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• 제46권2호
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• pp.132-142
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• 2018

An elephant digests only around 30~45% of what it consumes; therefore the undigested material mainly passes as intact fibres. Elephant food is usually composed of grass, leaves, twigs, bark, fruit and seed pods. This research aimed to utilize the elephant dung fibers as material for composite board and citric acid as a bonding agent. Citric acid contents in this research were set at 0 wt% (binderless composite board), 10 wt%, 20 wt%, and 30 wt% based on dry weight particles, while the target density was set at $0.8g/cm^3$. Pressing temperatures were set at $180^{\circ}C$ and $200^{\circ}C$ with the pressing time was 10 minutes. Physical and mechanical properties tests were then performed according to Japanese Industrial Standard A 5905. The result showed that elephant dung fibers could be used as potential materials for composite board. Addition of citric acid and pressing temperature significantly increased the quality of composite board. Infrared analysis indicated that the presence of ester linkages much higher with the increasing of citric acid content and pressing temperature. The optimum properties of composite board made from elephant dung fibers could be achieved at pressing temperature of $200^{\circ}C$ and a citric acid content of 20 wt%.

• 대한가정학회지
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• 제17권1호
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• pp.1-9
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• 1979

The damaging effects of hemp and cotton by Aspergillus sp, and penicillum sp, which grow successfully on cotton were studied. The damages were measured after cultivated at $30^{\circ}C$ for 10 days the fabrics with Aspergillus sp,and Penicillum sp, respectically, in various conditions. The effects of cell-free extract produced from fungus were also investigated. The results of obtained could be summeried as follows : 1) Cultivation of fungi on fibre in malt extract agar was better than that in czapeck agar. 2) Tnsile strength of the fabrics was deteriortated most easily in czapeak agar at the rae of 49.8%. 3)Growth of fungi was promoted by starching the fibre but tensile strength was felled -off , however, by starching, propagation of fungi was superior on cotton to on hemp. 4) In case of hemp, propagation of fungi was inferior to in case of cotton but the tensile strength was deteriorated at the rate of 26-33%. 5) In case of starched hemp, the tensile strength was deteriorated Slowly in first 8 days, but after 8 days there was no particular change. There was no particular change of tensile strength by starching in cotton. 6) It seemed that a damage of fibre was accelerated because the fungus grow not only on the surface of fabrics but also the inner of those. 7) By treatment of cell-free produced form fungi, the tensile strength of hemp falled off at the rate of 50-65% in first 24 hours, since then the tensile strength was deteriorated slowly for 4 days, but after incubation for 4 days was not changed. But the tensile strength of cotton by cell-free extracts was not effected.