• 전기의세계
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• v.15 no.4
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• pp.22-26
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• 1966

전기기기를 수리 또는 제작할 때에 바니쉬처리된 부품들을 건조하는 건조로로서 여러가지 형식의 건조로들이 사용된다. 이와같은 바니쉬 건조로를 설계 또는 제작을 할 때에는 생산량을 토대로한 로의 크기 및 건조온도를 유지하기 위한 소요열량의 계산외에 전기한 바와 같은 노내 바니쉬용매의 증기 밀도에 대한 검토도 필요하게 된다. 또 건조로를 운전할 때에도 노내 바니쉬용매의 증기밀도를 허용치 이하로 유지해서 안전한 운전을 도모해야 할 것이다.

• Journal of Navigation and Port Research
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• v.29 no.3 s.99
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• pp.263-268
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• 2005

Laboratory evaluation of the effect of fines, confine stress and dry density on the permeability characteristics in sand columns is presented. The triaxial permeability tests were conducted on different contents of fines(5, 15, 25, $35{\%}$), confine stress ($\sigma_3^'=0.5,\;1.0,\;2.0,\;3.0{\cal}kg/{\cal}cm^2$), and dry density($\gamma_d=1.50,\;1.55,\;1.60,\;1.65{\cal}g{\cal}cm^3$). The results of triaxial permeability tests showed that as the contents of fines, confine stress and dry density became increase permeability became decrease. For the contents of fines, when the fines that smaller than $0.01{\cal}mm$ increases the permeability decreases significantly. For the confine stress and the dry density, the permeability is decreased significantly at changes of the confine stress($\sigma_3^'=0.5{\~}1.0{\cal}kg/{\cal}cm^2$) and the dry density($\gamma_d=1.50{\~}1.55{\cal}g/{\cal}cm^3$) at lower levels.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.241-249
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• 1994

Leaf diffusive resistance (LDR), stomatal density, length of guard cell and hair density of leaves of 6 oak species were determined under withdrawal of water, and their strategies of drought stress were analyzed by principal component analysis. LDR of Quercus acutissima, Q. aliena and Q. serrata increased earlier than those of the other species at high leaf water potential $({\Psi}_{leaf})$ or low water saturation deficit (WSD), which was an avoidance mechanism reducing damage by water stress. Q. variabilis with low stomatal density, small stomatal size and high hair density had avoidance mechanisms increasing LDR at high $({\Psi}_{leaf})$ However, Q. mongolica and Q. dentata increased LDR at low $({\Psi}_{leaf})$ as xeric species do. Results from principal component analysis on the 15 variables related to strategies of drought stress indicated that the 6 oak species were divided into 2 groups: (1) Q. acutissima, Q. aliena and Q. serrata as mesic habitat species and (2) Q. variabilis, Q. mongolica and Q. dentata as xeric habitat species. Among three xeric species Q. acutissima differed from the other two species in the drought strategies such as high hair density, low stornatal density, high leaf area ratio, stomatal closing at low $({\Psi}_{leaf})$ and small cell wall elasticity. The results could reasonably explain their drought strategies in natural habitat.

• Geophysics and Geophysical Exploration
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• v.18 no.4
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• pp.171-180
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• 2015

Electrical resistivity of 23 core samples from Ulleung Island at dry or saturated condition has been measured along with dry density and effective porosity, and the relations between the properties has also been discussed. Upper and lower bounds of electrical resistivity at room temperature can be provided by the dry- and saturated-resistivity, respectively. Injecting nitrogen gas to the pore space at the very end of drying process can prevent humid air from getting into the pore space, so that measurement of dry-resistivity can be less affected by humidity in the air. Dry density and porosity have very close correlation; the ratio between increase of porosity and the decrease of density showed distinct relation to the rock types, such that basaltic rocks showed higher ratio while trachytic rocks showed lower. Saturated resistivity showed close correlation to density and effective porosity of the rock sample, while dry resistivity didn't.

• Geophysics and Geophysical Exploration
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• v.21 no.4
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• pp.220-230
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• 2018

When thermal conductivity of rock is measured with PEDB (Portable Electronic Divided Bar) in a laboratory, it can be greatly influenced by the change of room temperature. Therefore, measuring the thermal conductivity in a thermo-hygrostat is necessary, where it can remain in its constant temperature and humidity condition. In this study, a system for thermal conductivity measurement in a thermo-hygrostat has been set up and the thermal conductivities for the 45 samples collected from GH3 and GH4 boreholes in Ulleung Island have been measured both in dry and saturated conditions. Also, the correlations between those thermal conductivities, density, and effective porosity have been discussed. As a result of correlation analysis among the thermal conductivity, density, and effective porosity, it showed higher correlation with dry samples than saturated samples. Especially, thermal conductivity ratio between saturated and dry conditions shows very high correlation ($R^2=0.90$) with effective porosity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1320-1325
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• 2012

This study investigated the bulk properties of red pepper powders according to drying method and variety. Bulk density, compressive characteristics, irrecoverable work, dynamic angle, and stress relaxation were investigated. Loose bulk density ranged between 0.420 $g/cm^3$ for Cheongyang cultivar and 0.427 $g/cm^3$ for Hanbando cultivar by hot-air drying. The highest tapped bulk density was 0.586 $g/cm^3$ for Hanbando cultivar by far-infrared drying and the lowest value was 0.523 $g/cm^3$ for Hanbando cultivar by sun drying. Hausner ratio reached a maximum value of 1.370 for Hanbando cultivar by far-infrared drying. Compressibility ranged between 0.0016 for Cheongyang cultivar by sun drying and 0.0023 for Hanbando cultivar by far-infrared drying. Compression ratio reached a maximum value of 1.032 for Hanbando cultivar by hot-air drying. Dynamic angle of repose ranged between 37.47 and $42.97^{\circ}$. Irrecoverable work ranged between 76.0 and 81.7%. Relaxation reached a maximum value of 24.31% for Cheongyang cultivar by far-infrared drying.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.221-227
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• 1999

베일러 작업에 있어 작업시의 볏짚의 함수율은 베일러의 작업성, 저장 중에 발생하는 볏짚의 물리적, 화학적 변화 등에 있어 중요한 요소로 작용한다. 국내의 경우 가을철에 청명하고 건조한 날이 많아 볏짚이 빠르게 건조되나 일기가 고르지 못한 경우에는 높은 함수율에서도 작업을 해야할 경우가 생긴다. 높은 함수율에서 작업하는 경우 필연적으로 베일의 질적 저하가 일어나는데 이를 줄이는 방법의 하나로 밀도를 조정하는 방법이 있다. (중략)

• Korean Journal of Food Science and Technology
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• v.4 no.4
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• pp.276-284
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• 1972

A strain of Bacillus sp. which has powerful enzymatic activity and sets free a little amount of ammonia nitrogen and large amount of amino nitrogen was separated from Meju, Denzang, Chungkukjang, and paddy straw to make the soy-sauce rapidly and conveniently in the various mixing ratio of steamed soy-bean and wheat parched or steamed. Total nitrogen and amino nitrogen were increased during the maturing. The acidity of soy-sauce was increased to $1.15{\sim}1.98%$ than ordinary soy-sauce. pH were ranged in $4.6{\sim}6.0%$. The fermenting time takes 30 days while it takes at least 4 monthes in ordinary method. The best results were obtained with the mixed ratio of 1 : 1 or 1 : 2 (wheat : soy-bean).

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.63-63
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• 2000

저급의 고지 원료를 두께 방향으로 고온 압착을 가하여 건조함으로써 전반적인 종이 물성 을 향상시키는 콘디벨트 건조 방식은 70년대 중반부터 80년대에 이르는 10여년에 걸친 개발 과정을 거쳤으며 90년대에 들어서 핀랜드의 Inkeroinen에 위치한 V alemt- Tarnpella의 연구 소에 최초의 파일로트 설비가 설치되었으며 그 후 1996년에는 핀랜드 ENSO사의 P Pank밟oski 판지공장에 설치됨으로써 세계 최초의 상업생산설비를 이루게 되었다. 기존의 실린더 건조 기술과 비교할 때 콘디벨트 건조방식은 건조속도를 약 5-15배 향상시킬 수 있 으며, 건조 에너지 절감에 큰 효과가 있을 뿐만 아니라 기존의 실린더 건조시 종이가 폭방 향으로 수축되 어 인장 stiffness와 압축 강도 동의 종이 물성 이 저 하되 는 반면 습윤상태 의 섬유를 120도씨이상에서 가열에 의해 리그닌을 연화시킴과 동시에 섬유의 유연성을 증가시켜 준다. 그리고 높은 압력을 가해줌으로써 섬유간의 결합 면적을 증가시키고 건조시 종이의 폭방향의 수축을 감소시켜 인장강도, 내부결합강도, 밀도, 표면평활성, 투기저항성 등 종이의 물성을 대폭 향상시켜주는 혁신적인 제지기술로 인정받고 있으며 국내의 경우 현재 1998년 부터 상업생산을 이루어짐으로써 그 공헌도는 매우 크다고 할 수 있다. 골판지의 주원료가 되는 국산 골판지 고지 (Korean old corrugated container, K KOCC)의 거듭된 재생처리로 인하여 미세분의 함량이 전체 지료의 절반 이상에 달할 뿐만 아니라, 섬유가 각질화와 단섬유화로 인하여 고온압착 건조처리 만으로는 골판지 고지로 생 산된 원지의 강도를 버진펄프로 생산된 원지가 가지는 강도에 준하는 강도로 향상시키는데 한계점을 가지게 된다. 유럽의 제지선진국들은 골판지 원지의 강도를 향상시키는 방편으로 표변에 전분 사이즈 프레스 처리를 도입하였으며 본 연구에서는 고온 압착 건조 처리 설비를 활용한 전분 표면처리의 가능성을 검토하고 골판지 원지의 강도를 향상시키기 위한 표면처리조건을 탐색하였다.

• Journal of the Korean Geotechnical Society
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• v.29 no.7
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• pp.37-46
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• 2013

Various sizes of gravels are included in the most field soils that are utilized for civil constructions. Especially, the small amounts of gravel are often included in selected soils for backfill materials, earth dams, and subbase ground. In such cases, the small amounts of mixed gravel and its shape may influence the determination of dry density of soils, which results in an inaccurate degree of compaction for soils in the field. In this study, a dry density of sand with various gravel contents (0, 10, 17, 23, 29 and 33%) and three different sizes (2.0-2.36, 3.35-4.75, 5.6-10.0 mm) was experimentally investigated for compacted or loosely packed conditions. The loosely packed sand with gravels was simulated by pouring sand into compaction mould and its density was determined. When a 33% of gravel content was mixed with sand, its dry density increased up to 15-20% for compacted specimen and 20-23% for loosely packed specimen. When a gravel content and size were the same, a dry density of compacted specimen was $0.1-0.16g/cm^3$ higher than that of loosely packed specimen. Even though the same gravel content was used, a dry density of sand with big gravels was $0.04-0.08g/cm^3$ higher than that of sand with small gravels for compacted specimen and $0.03-0.05g/cm^3$ for loosely packed specimen.