• 한국가금학회지
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• 제19권4호
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• pp.197-204
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• 1992

본 실험은 난백 191g(시험 1)과 난백 222g(실험 2)에 자당(백색) 150g씩을 첨가한 2개의 실험구로 나누고 다시 각 실험구에 난황 0. 8.71, 17.43및 24.14g 첨가구로서 4구분하였으며 $50^{\circ}C$의 shaking water bath 내에서 1분간 92 왕복 속도로서 진탕시킴과 동시에 2, 4, 6, 8, 10및 12시간 후까지 경시적으로 pH와 비중을 측정하였다. 1. 전 시험구간에 있어서 shaking시간에 따라 pH와 비중은 경시적으로 증가되었으나 난황의 첨가량에 따라 pH 비중은 낮아졌다. 2. 실험 1과 2에서 shaking 10 시간 후 의 pH가 최고치를 나타냈으나, 그 이상의 증가는 없었다. 3. 실험 1과 2에서 얻어진 pH와 비중간에는 다음과 같은 높은 정의 상관관계를 나타내었다. (실험 1) Y＝0.1081X＋0.272(r＝0.900$^{**}$ ), (실험 2) Y＝0.083X ＋0.476(r＝0.825$^{**}$ ).

• 동아시아식생활학회지
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• 제23권3호
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• pp.341-348
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• 2013

The Rubus coreanus Miquel concentrate was added in 0 (control), 10, 20, 30, and 40% substitution ratios by weight per sugar. The specific gravity and water content in pound cake batter tended to increase specific gravity according to the added Rubus coreanus Miquel concentrate. The volume, weight, and specific loaf volume in pound cake tended to decrease by according to the addition Rubus coreanus Miquel concentrate. Moisture contents in pound cake tended to increase long the addition Rubus coreanus Miquel concentrate. Brix and pH also decreased. 'L' and 'b' along with the increase in 'a' values were followed in proportion to the substitution ratio. Typical textural parameters like hardness, gumminess, and chewiness were increased in proportion to the substitution ratios, but springiness decreased. Adhesiveness and cohesiveness did not show any considerable differences between the pound cakes. The sensory evaluation showed a high preference for pound cake made with 30% Rubus coreanus Miquel concentrate.

• Journal of the Korean Wood Science and Technology
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• 제39권3호
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• pp.252-257
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• 2011

국내에서 생산되는 목재에 대한 나사못 유지력을 기존의 식으로부터 수정된 예측 식으로 나타내기 위해 나사 못 뽑기 실험을 실시했다. 본 연구에 사용된 나사못은 No. 6, No. 8 및 No. 10이었다. 예측 식은 길이가 서로 다른 No. 8 나사못의 실험결과와 매우 일치하였다. 나사못 유지력의 예측 식은 나사못의 직경과 관입길이 및 목재비중의 함수로 나타냈다. 예측 식은 나사못 길이가 25와 30 mm에서 5% 이내로 작게 예측되었으나 18과 38 mm에서 큰 값을 보였다.

• 청정기술
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• 제8권2호
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• pp.67-76
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• 2002

Dewatered sludge of 400,000t/y from water treatment plants in Korea is being disposed through landfill and ocean dumping. However, the disposal is posing more and more serious environmental problems at the same time not only because of landfill site shortage in municipal suburbs, but because of the concern it will contaminate the oceans. In this study, the research on utilizing the sludge dried by flash dryer as covering soil in the landfill sites was carried out to solve these problems on environmental affinity. Both dewatered and dried sludge were exposed to the natural condition and observed according to the atmospheric changes. An experiment of soil engineering characteristics of the dried sludge and tests on mixed sludge(silty sandy soil : dried sludge = 10:90 ~ 30:70) such as particle size distribution, liquid and plastic limit, moisture content, specific gravity and compaction test were carried out. According to the compaction test, the compaction was confirmed as the optimum water content ratio was observed in the condition of SM-silty sand of particle size distribution, NP of liquid and plastic limit, 101.4% of moisture content, 2.04~2.12 of specific gravity. The results showed that dried sludges mixed with at least 30% of natural soil could be used as daily covering soil in the landfill sites.

• 에너지공학
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• 제9권1호
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• pp.47-53
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• 2000

This paper is to propose the concept and performance of a gravity engine which could extract energy from sea or river as a clean. renewable and sustainable power. the vertical motion of the buoyancy cylinder of the present gravity engine is converted to the mechanical work directly without any hydraulic loss. The positive net energy between the imposed and harnessed one is achieved by the specific operating procedure. The detailed derivation of the energy balance is made based on the first principle of thermodynamics. The calculation demonstrates that the present gravity engine could harness more energy than the conventional turbine system in the same basin area because of the relatively high efficiency in the energy conversion system and added mass from the buoyancy cylinder.

• Journal of the Korean Wood Science and Technology
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• 제10권3호
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• pp.88-95
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• 1982

본(本) 시험(試驗)은 강원도산(江原道産) 소나무의 기건상태(氣乾狀態)에 있는 심재(心材)와 변재의 추재율(秋材率), 기건비중(氣乾比重), 종압축강도 그리고 추재율(秋材率)과 기건비중(氣乾比重)의 관계, 추재율(秋材率)과 종압축강도의 관계, 비중(比重)과 종압축강도의 관계 등을 알고자 하였으며, 분석(分析)한 결과(結果)는 다음과 같다. 1. 심재(心材)의 연륜폭(年輪幅)은 추재율(秋材率)과 종압축강도에 뚜렷한 영향을 주고 있었으며, 연륜폭(年輪幅)이 감소함에 따라 추재율(秋材率)과 종압축강도는 상응하여 증대(增大)했다. 그러나 기건비중(氣乾比重)은 연륜폭별(年輪幅別)에따라 유의적(有意的)인 차이(差異)는 나타나지 않았다. 3. 심재(心材)와 변재 모두 추재율(秋材率)과 기건비중간(氣乾比重間)에는 직선적(直線的)인 관계(關係)가 나타났으며, 심재(心材)는 $x_{12}$=0.31+0.006 x 식(式)으로, 변재는 $r_{12}$=0.27+0.007 x 식(式)으로 나타났다. 심재(心材)와 변재 모두 추재율(秋材率)과 종압축강도에도 역시 직선적(直線的) 관계(關係)가 나타났으며 심재(心材)는 ${\sigma}c11$=343+1.93 x 식(式)으로, 변재는 ${\sigma}c11$=208+6.97 x 식(式)으로 나타났다.

• East Asian Economic Review
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• 제26권2호
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• pp.143-169
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• 2022

This study investigates the effect of economic factors on immigration using the gravity model of immigration. Cross-sectional regression and panel data analyses are conducted from 2000 to 2019 using the OECD International Migration Database, which consists of 36 destination countries and 201 countries of origin. The Poisson pseudo-maximum-likelihood method, which can effectively correct potential biased estimates caused by zeros in the immigration data, is used for estimation. The results indicate that the economic factors strengthened after the global financial crisis. Additionally, this effect varies depending on the type of immigration (the income level of origin country). The gravity model applied to immigration performs reasonably well, but it is necessary to consider the country-specific and time-varying characteristics.

• 설비공학논문집
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• 제11권3호
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• pp.384-390
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• 1999

A vibrating U-Tube decimeter has been evaluated as a sensor for measuring the concentration of oil in the liquid line of a refrigeration system. Calibration and performance tests were conducted under simulated liquid-line conditions for R-407C/POE oil and R-410A/POE oil mixtures in oil concentration from 0 to 15 weight percent. Test temperatures ranged from 20 to 5$0^{\circ}C$. As a result of test, oil concentration correlations are presented in terms of specific gravity at each constant temperature. These equations enable to predict the oil concentration without any extraction of the mixture, and can be applied for R-407C/POE oil and R-410A/POE oil mixtures.

• 한국수산과학회지
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• 제15권3호
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• pp.185-190
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• 1982

다획성 어종인 고등어, 정어리, 말쥐치 등을 연제품 기타 식품소재로 이용하기 위해서는 다양처리를 위한 기계처리가 필요하나 적색육조에 많은 혈합육의 분리가 어려워 품질에 문제점이 있다. 기계처리적정에서 보통육과 혈합육을 분리하는 방법으로 당용액의 비중차에 의한 분리유과를 검토한 결과를 요약하면 다음과 같다. (1) 보통육과 혈합육을 분리할 수 있는 유효비중한계는 고등어의 경우 $1.067\sim1.072$, 정어리의 경우$1.02\sim1.070$ 말쥐치의 경우 $1.073\sim1.077$였다. (2) 육립자의 크기에 따른 분리율은 chopper 세공판의 공경이 0.2cm일 때에 $90\%$였고 0.3cm일 때에 $60\%$였다. (3) 육립자의 밀도에 따른 분리효과는 당용액에서의 침강력 높이가 1.8cm정도, 즉 육입자 밀도 $1g/cm^2$일 때 분리율이 $92\%$였고, 즉 $5g/cm^2$일 매에는 $59\%$로 낮았다. (4) 자당용액에서는 부상분리층이 25분 경과하여도 침강하지 않았으나 포도당액에서는 5분후부터 서서히 침강하였다. (5)당용액의 비중이 높아짐에 따라서 유지의 분리율 높았으며 유효비중한계내에서도 $90\%$정도의 지방을 분리할 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제35권5호
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• pp.67-75
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• 2007

As a part of abating the formaldehyde emission of urea-formaldehyde (UF) resin adhesive by lowering formaldehyde to urea (F/U) mole ratio, this study was conducted to investigate properties of UF resin adhesive with different F/U mole ratios. UF resin adhesives were synthesized at different F/U mole ratios of 1.6, 1.4, 1.2, and 1.0. Properties of UF resin adhesives measured were non-volatile solids content, pH level, viscosity, water tolerance, specific gravity, gel time and free formaldehyde content. In addition, a linear relationship between non-volatile solids content and sucrose concentration measured by a refractometer was established for a faster determination of the non-volatile solids content of UF resin. As F/U mole ratio was lowered, non-volatile solids content, pH, specific gravity, water tolerance, and gel time increased while free formaldehyde content and viscosity were decreased. These results suggested that the amount of free formaldehyde strongly affected the reactivity of UF resin. Lowering F/U mole ratio of UF resin as a way of abating formaldehyde emission consequently requires improving its reactivity.