• 펄프종이기술
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• 제33권2호
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• pp.24-31
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• 2001

As a novel method to improve strength properties of recycled test liner, Condebelt press drying system was introduced and adopted into Korea. New press drying treatment could enhance the surface and strength properties in accordance with the increase of sheet density. However, Condebelt drying can not increase the density of repeatedly recycled test liner as much as that of virgin UKP and at the same density condition, the strength of Condebelt press dried UKP is greater than that of press dried test liner. In order to increase the strength of test liner, two attempts were tried in this study. First, addition of polyelectrolytes, dry strength agent was investigated with a view to promote the fiber bonding potential of reclaimed corrugated container pulp. Second, blending effect of fines were analyzed in an aims of increasing density and strength of test liner. The results were as follows; Even in the case of test liner densified by Condebelt press dryer, addition of amphoteric PAM as a dry strength agent was effective in increasing strength properties and so the effect of dry strength agent on improving bonding potential of recycled OCC fiber could be confirmed. As an appropriate addition level of amphoteric PAM, below 1% based on dry pulp weight was suggested. Different from virgin UKP, density of recycled test liner can be increased by the blending of OCC fines and strength properties also can be improved. However, excessive blending of OCC fines could result in decreasing of density and serious weakening of test liner. The best blending ration of fines in test liner can be determined as about 30%. Taking into account the fines content in general OCC pulp as 50%, excessive 20% of fines were supposed to be fractionated and removed in order to achieve the best strength of Condebelt press dried test liner.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.793-794
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• 2012

• Asian-Australasian Journal of Animal Sciences
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• 제22권11호
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• pp.1531-1539
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• 2009

This study compared the nutritional value of canola (B. napa) and mustard (B. hirta) press cakes obtained from the biodiesel industry as ingredients for use in diets fed to broiler chickens. A total of 210, one-day old, male broiler chicks were randomly assigned to one of seven dietary treatments. The control diet was based on wheat and soybean meal and contained 15% canola meal. For the experimental diets, 5, 10 or 15% of the canola meal was replaced with an equal amount of either canola or mustard biodiesel press cake. Dry matter and neutral detergent fiber digestibility were significantly higher for birds fed diets containing either canola or mustard biodiesel press cake compared with canola meal. Dry matter and neutral detergent fiber digestibility of the canola biodiesel press cakes was higher than the mustard biodiesel press cakes. Ether extract digestibility and nitrogen retention were significantly higher for birds fed canola biodiesel press cake compared with canola meal and mustard biodiesel press cake. Body weight gain and feed intake did not differ between birds fed canola or mustard biodiesel press cake and canola meal. In addition, there was no significant difference in body weight gain or feed intake between birds fed diets containing canola or mustard biodiesel press cake. Feed conversion was significantly improved for birds fed either canola or mustard biodiesel press cake compared with canola meal. Mortality was unaffected by treatment. Since the performance of broilers fed canola biodiesel press cakes was essentially the same as that of broilers fed canola meal, it is difficult to justify a premium to be paid for canola biodiesel press cake over that paid for canola meal. In addition, there was no difference in the performance of broilers fed biodiesel press cake obtained from canola or mustard seed. As mustard seeds are generally available at a lower price than canola seed, there may be some incentive to use mustard rather than canola seed for producing biodiesel press cake for use in poultry production.

• 소성∙가공
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• 제25권4호
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• pp.242-247
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• 2016

CFD simulation with FlowVision^® is used to evaluate the capability of cooling channel in hot press forming dies. Two different types of cooling channels, dry drilled and pocket types are considered for comparison. Two different approaches for simulating cooling channel are considered. One is single-phase velocity calculation for coolant only and the other is multiphase thermal and velocity calculation for die, blank and coolant all together. Both approaches show better cooling performance in pocket type cooling channel. Also both approaches show their own effectiveness in designing cooling channel of hot press forming dies.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.573-574
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• 2012

• Geomechanics and Engineering
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• 제28권4호
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• pp.375-384
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• 2022

The glacial tills and shales in Midwestern states of the USA often show strength degradation after construction. They are often in need of applying soil modification techniques to remediate their strength degradation with weathering process. This study investigated the weathering durability of these natural soils and biopolymer treated soils by comparing direct shear test results for wet-dry and wet-freeze-thaw-dry cycled specimens. The tests showed that untreated glacial tills maintained only 62% and 50% initial shear strength after eight wet-dry cycles and eight wet-freeze-thaw-dry cycles, respectively. These untreated soils could not withstand by themselves after 16 weathering cycles. The same soils treated with 1.5% (by dry weight) food-grade Xanthan gum maintained 140% and 88% initial shear strength of untreated soils after 16 weathering cycles for wet-dry cycles and wet-freeze-thaw-dry cycles, respectively. The same soils treated with 1.5% (by dry weight) Gellan gum maintained 82% and 60% initial shear strength of untreated ones after 16 weathering cycles, respectively. Similar results were obtained for crushed shales, manifesting that the biopolymerization method may be adopted as a new eco-friendly method to enhance the weathering durability of these problematic soils of glacial tills and shales.

• Structural Engineering and Mechanics
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• 제2권1호
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• pp.63-80
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• 1994

A cable is considered as a system of helical wires and a core with distributed dry friction forces at their interfaces. Deformations of the cable subjected to a uniform bending are analyzed. It is shown that there is a critical bending curvature when a slip at the wire-core interface occurs. It originates at the neutral axis of the cross section of the cable and then spreads symmetrically over the cross section with the increase of bending. The effect of slippage on the cable stiffness is investigated. This model is also used to analyze a cable under the quasi-static cyclic bending. Explicit expression for the hysteretic losses per cycle of bending is derived. Numerical examples are given to show the influence of dry friction and helix angle on the bending stiffness and hysteretic losses in the cable.

• Structural Engineering and Mechanics
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• 제75권2호
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• pp.239-246
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• 2020

In this paper, a novel analytical method, Max-Min Approach (MMA), has been presented and applied to consider the nonlinear vibration of dry cask storage systems. The nonlinear governing equation of the structure has been developed using the shell theory. The MMA results are compared with numerical solutions derived by Runge-Kutta's Method (RKM). The results indicate a satisfying agreement between MMA and numerical solutions. Parametric studies have been conducted on the nonlinear frequency of dry casks. The phase-plan of the problem is also presented and discussed. The proposed approach can potentially ca be extended to highly nonlinear problems.

• Computers and Concrete
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• 제23권4호
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• pp.267-272
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• 2019

In order to study the effect of moisture on the compressive strength of low-strength hollow concrete blocks, an experimental study was carried out on 96 samples of locally manufactured hollow concrete blocks collected from three different locations. Uniaxial compression tests were conducted on dry specimens and three types of saturated specimens with moisture contents of 30%, 50% and 80% respectively. The range of moisture content adopted covered the range within which the concrete block samples are saturated in the dry and monsoon seasons. The compressive strength of low-strength hollow concrete blocks decreases with increase in moisture content and the relationship between compressive strength of hollow concrete blocks and their moisture content can be considered to be linear. However, the strength degradation of 30% moist concrete blocks with respect to dry blocks is relatively low and can be considered to be comparable to dry concrete blocks. A formula indicating the relationship between the moisture content and compressive strength of low-strength hollow concrete blocks is also proposed.

• Journal of Nutrition and Health
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• 제15권3호
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• pp.186-193
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• 1982

육제품(肉製品)에 대한 세계적 Nitrite 함량 규제한계를 검토하고 우리나라의 환경조건 하에서 가내가공(家內加工)한 dry ham과 dry sausage의 Nitrite 잔존량을 조사하였다. 그 결과는 다음과 같다. 1) Nitrite와 Nate를 합(合)하여 ham에 264ppm, sausage에 185ppm $NaNO_2$ 당량을 첨가하여 자가제조(自家製造)한 dry meat products의 Nitrite 잔존량(殘存量)은 법적허용한계 양(量) 70ppm에 미달한 $32{\sim}67ppm$이었다. 시중판매제품(市中販賣製品) press ham들도 Nitrite 잔존량이 40ppm이하이며 제품회사마다 많은 차가 있었다. 2) Nitrite 잔존량은 제조첫날로 부터 증가하여 dry sausage는 2주(週), 또는 3주(週)에, dry ham은 5주(週)에 가장 높은 67ppnm을 나타냈고 저장기간이 길수록 점차 낮아졌다. 내장에 Casing한 Sausage와 여름철에 제조한 ham에선 각각 3주(週)와 4주(週)에 이미 10ppm 이하로 떨어져 있었다. 이는 Nitrite 잔존량이 제품의 염적 및 숙성과정에서 여러 가지 여건에 따라 차가 심한 것을 보여 준다. 3) Nitrate 함량은 Nitrite 함량이 가장 높은데 (sausage 3주, ham 5주에) 가장 낮은 상반된 값을 보였고 저장기간이 길수록 높아졌다.