• Journal of Forest and Environmental Science
• /
• 제33권2호
• /
• pp.97-104
• /
• 2017

Investigation was carried out on response of Tetrapleura tetraptera (Schum. and Thonn.) to soil, water and light with the view of its domestication and introduction to different ecological regions. The experiment was arranged in a factorial experiment of $3{\times}3{\times}3$ in a completely randomized design (CRD) with three replicates. The factors were: soil textural class (Loamy sand, Sand and Sandy clay loam), watering regime (daily, twice a week and once a week) and light intensity (100%, 75% and 50%). Soil textural classes had significant influence on collar diameter, stem height, number of leaflets, root/shoot ratio and relative growth rate of Tetrapleura seedlings. Seedlings grown on loamy sand recorded the highest mean value- 2.28 mm for collar diameter, stem height- 12.9 cm, number of leaflets- 19.9, chlorophyll b- $0.34mg\;mL^{-1}$, leaf relative water content- 27.4% and relative growth rate- $0.037mg\;g^{-1}\;day^{-1}$. Watering regime had significant influence on the collar diameter of Tetrapleura. Seedlings watered daily recorded the highest mean value- 2.25 mm for collar diameter. Light intensity significantly influenced collar diameter and root/shoot ratio. Seedlings exposed to 100% light intensity recorded higher mean value for collar diameter- 2.28 mm and root/shoot ratio- 1.481 cm. The interaction between soil textural class and light intensity significantly affected collar diameter, stem height and number of leaflets. Higher mean value for collar diameter (2.47 mm) stem height (13.25 cm) and number of leaflets (21.16) were recorded while the interaction between soil textural class, light intensity and watering regime was significant for only number of leaflets. Tetrapleura exhibited some level of tolerance to different soil texture, drought and light intensity. Therefore, Tetrapleura has the potentials to be raised in different ecological zones characterized by difference in soil, rainfall and amount of sunshine.

• 농업생명과학연구
• /
• 제52권6호
• /
• pp.37-47
• /
• 2018

본 연구의 목적은 전국에 분포하는 일본잎갈나무 임분에 대해 산림시업 수행이 직경분포변화에 미치는 영향에 대해 분석하였다. 본 연구에 사용한 자료는 국가산림자원조사 중 시업지 232plots, 비시업지 47plots의 고정표본점 자료를 활용하였다. 직경분포모델은 Weibull 누적분포함수를 사용하였으며, 분석 방법에는 백분위(Percentile)에 근거한 직경모형추정, 백분위(Percentile)에 대한 모수복구 방법을 사용하였다. 개발한 모델을 이용하여 산림시업의 수행여부에 따른 시나리오(임령, 지위지수, 임분밀도) 별임분생장량을 예측한 결과, 시업지 임분의 최대임목본수를 차지하는 평균 흉고직경의 이동이 비시업지 임분에 비해 이동량과 생장량이 더 높게 나타났으며, 대경목이 차지하는 비율 또한 시업지 임분이 높게 예측되었다. 본 연구의 결과는 직경급에 따른 목재생산량의 장기적인 예측과 동적인 임분구조 해석에 기초적인 정보를 제공할 수 있을 것으로 사료되어진다.

• Macromolecular Research
• /
• 제13권5호
• /
• pp.385-390
• /
• 2005

The electrospinning process is a fascinating method to fabricate small nanosized fibers of diameter several hundred nanometers. Surfactant-polymer solutions were prepared by adding poly(vinyl alcohol) (PVOH) to distilled water with cationic, anionic, amphoteric, and non-ionic surfactants. Average diameter of the electrospun PVOH fibers prepared from PVOH solution was over 300 nm, and was decreased to 150 nm for the mixture of PVOH/amphoteric surfactant. To explain the formation of ultra fine fiber, the characteristic properties in a mixture of PVOH/surfactant such as surface tension, viscosity, and conductivity were determined. In this paper, the effect of interactions between polymers with different classes of surfactants on the morphological and mechanical properties of electrospun PVOH nonwoven mats was broadly investigated.

• 한국산림과학회지
• /
• 제6권1호
• /
• pp.1-5
• /
• 1967

We studied on the bark Percentage of red pine (Pinus denssiflora S & Z) and tarch (Larix Kaemdferi sargent) and obtained the results as follows: (1) For diameter classes from 8 to 38 cm in red pine. the linear equation adopts the relation of the bark percentage to the diameter more accurately than the logarithmic equation. (2) The difference between the regression equation of the bark percentage between red pine and Larch is significant and the correlation cofficient in red Pine is high so that standard error of red Pine is lower than its value of Larch. We established, therefore the tables of bark percentage for each species by applying the following regression equations. red Pine Y=10.08205-0.08794x Larch Y=10.3527-0.17071x.

• Animal cells and systems
• /
• 제1권2호
• /
• pp.341-344
• /
• 1997

Receptor-mediated endocytosis has been suggested for a stage-specific transport mechanism of vitellogenin into the oocytes of a sabellid poly chaete, Pseudopotamilla occelata. Membrane proteins of oocytes of three size classes, including small (30-70 $\mu\textrm{m}$ in diameter), intermediate (70-140 $\mu\textrm{m}$ in diameter) and large (180-200 $\mu\textrm{m}$ in diameter), showed a atage-specific variation. Coelomic fluid proteins (CP), ass$\mu\textrm{m}$ed to be vitellogenin, consists of several proteins, which showed quite a different pattern from that of yolk proteins. Incorporation of $^{125}I$-CP into the oocytes of the intermediate size class almost linearly increases with time, showing a contrast to the pattern of the large size class, in which the incorporation is low and approaches a plateau, suggesting the vitellogenin transports by a regulated process only in the intermediate size class. Vitellogenin receptor proteins were identified to be 60 kDa and 68 kDa only in the intermediate size class by a ligand blotting test.

• Nuclear Engineering and Technology
• /
• 제53권7호
• /
• pp.2277-2288
• /
• 2021

To regulate the safety protocols in nuclear facilities, radioactive aerosols have been extensively researched to understand their health impacts. However, most measured particle-size distributions remain at low resolutions, with the particle sizes ranging from nanometer to micrometer. This study combines the high-resolution detection of 500 size classes, ranging from 6 nm to 10 ㎛, for aerodynamic diameter distributions, with a regional lung deposition calculation. We applied the new approach to characterize particle-size distributions of aerosols generated during the plasma arc cutting of simulated non-radioactive steel alloy wastes. The high-resolution measured data were used to calculate the deposition ratios of the aerosols in different lung regions. The deposition ratios in the alveolar sacs contained the dominant particle sizes ranging from 0.01 to 0.1 ㎛. We determined the distribution of various metals using different vapor pressures of the alloying components and analyzed the uncertainties of lung deposition calculations using the low-resolution aerodynamic diameter data simultaneously. In high-resolution data, the changes in aerosols that can penetrate the blood system were better captured, correcting their potential risks by a maximum of 42%. The combined calculations can aid the enhancement of high-resolution measuring equipment to effectively manage radiation safety in nuclear facilities.

• 한국산림과학회지
• /
• 제95권1호
• /
• pp.131-138
• /
• 2006

본 연구는 우리나라 천연활엽수림의 대표적 수종인 신갈 굴참나무를 대상으로 흉고직경 생장량 패턴을 알아보고, 14개의 임목 측정인자와 직경생장량과의 관계를 규명하기 위하여 실시하였다. 본 생장량 자료는 강원도 천연활엽수림지역에서 벌도 된 83본의 신갈 및 굴참나무에 대하여 수간석해를 통하여 분석하였다. 두 수종 모두 우세목의 경우 평균적으로 15~20년까지 흉고직경생장률이 높게 나타나다가 그 이후부터는 일정한 생장량을 갖고, 매년 0.09~0.83 cm/yr의 흉고직경생장을 하는 것으로 나타났다. 최근 5년간의 연년직경생장량은 신갈나무가 평균 0.28 cm/yr로 굴참나무 평균 0.27 cm/yr 자라는 것으로 실측되었으며, 두 수종 모두 우세목, 준우세목, 중간목, 피압목 순으로 생장이 좋은 것으로 확인되었다. 특히, 신갈나무의 경우는 수관급간에 직경생장량이 매우 유의적인 차이 (p<0.0001)가 있는 것으로 나타났다. 또한, 14개의 입목 측정인자와 조제변수를 이용하여 최근 5년간의 연년직경생장량과 Pearson 상관분석을 실시한 결과, 신갈나무의 경우 상대직경(r=0.64), 상대수고(r=0.61), 노출된 수관투영면적(r=0.58), 전체 수관투영면적(r=0.56)순으로 상관관계가 높게 나타났으며, 굴참나무는 흉고직경(r=0.57), 수관폭(r=0.55), 연령(r=0.39), 경쟁지수(r=-0.39), 수고(r=0.35)순으로 상관관계가 있는 것으로 나타났다.

• The Korean Journal of Ecology
• /
• 제27권3호
• /
• pp.165-171
• /
• 2004

상수리나무 뿌리의 분해율과 분해과정에 따른 영양염류의 변화를 조사하였다. 33개월경과 후 뿌리의 분해율은 직경 0.2㎝ 미만(R₁), 0.5∼1㎝(R₂), 1∼2㎝(R₃), 2∼4㎝(R₄)가 각각 49.6%, 47.5% 66.4%, 66.1%, 분해상수 k는 각각 0.249/yr, 0.234/yr, 0.397/yr, 0.393/yr로 직경이 큰 것의 분해율이 높았다. 상수리나무 뿌리는 유사한 직경의 상수리나무 가지에 비해 분해가 빠른 것으로 나타났다. 분해 과정에 따른 뿌리의 질소 함량은 모든 직경급에서 증가하는 경향을 보였다. 33개월경과 후 뿌리의 질소 잔존률은 R₁, R₂, R₃ 그리고 R₄ 각각 66.5%, 86.7%, 84.4%, 44.4%이었다. 분해중인 뿌리의 인 함량은 분해 초기에 감소하다 후반부에는 증가하는 경향을 보였으며, 33개월 후 인의 잔존률은 R₁, R₂, R₃ 그리고 R₄ 각각 64.7%, 62.4%, 93.1% 30.7%이었다. 분해중인 뿌리의 칼륨 함량은 분해가 진행됨에 따라 초기 값보다 현저하게 감소하였으며, 33개월경과 후 칼륨의 잔존률은 R₁, R₂, R₃그리고 R₄에서 각각 11.6%, 10.6%, 5.9%, 7.7%이었다. 분해과정 중 칼슘 함량의 변화는 직경급에 따라 달랐으며, 33개월경과 후 칼슘의 잔존률은 R₁, R₂, R₃ 그리고 R₄에서 각각 66.2%, 51.0%, 39.1%, 48.3%이었다. 뿌리의 마그네슘 함량은 직경이 작을수록 초기 함량이 높았으며, 분해가 진행됨에 따라 R₄에서는 초기 값에 비해 함량이 증가하였으나 Rl₁ R₂, R₃에서는 초기 값보다 감소하였다. 33개월경과 후 마그네슘 잔존률은 R₁, R₂, R₃ 그리고 R₄에서 각각 15.3%, 29.9%, 24.6%, 69.4%로 칼슘과는 달리 직경이 큰 뿌리에서 잔존률이 높았다.on of hub-and-spoke system, integration of logistics bases, introduction of (automatic) parking building, diversification of transportation mode, and etc. At the same time, we constructed three practically executable scenarios based on those ideas. The first is "Center Hub" scenario, the second is "Metropolitan Hub" scenario. The third and last scenario is "Regional Consolidation of Warehouses (distribution centers)".f worldly desire' and 'cordiality' that one could be deserved his diligency becoming a part of the harmonious idealistic living place. Fourthly, on the character of story teller. Originally he is a incomer of "Gang-Ho" from real world. so that reason, he is showing dualism not to deny the loyalty oath to his king, while he intends to satisfy with the life in "Gang- Ho" separating himself from real world. As a gentry, at that time, the loyalty oath is inevitable one and that is found from

• International Journal of Automotive Technology
• /
• 제7권7호
• /
• pp.847-852
• /
• 2006

A fitting process carried out in the automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that applies heat in the outer diameter of a gear to a suitable range under the tempering temperature and assembles the gear and the shaft made larger than the inner radius of the gear. Its stress depends on the yield strength of a gear. Press fitting is a method that generally squeezes gear toward that of a shaft at room temperature by a press. Another method heats warmly gear and safely squeezes it toward that of a shaft. A warm shrink fitting process for an automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by the process produced dimensional change in both outer diameter and profile of the gear so that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of a warm shrink fitting process in which design parameters such as contact pressure according to fitting interference between outer diameter of a shaft and inner diameter of a gear, fitting temperature, and profile tolerance of gear are involved. In this study, an closed form equation to predict the contact pressure and fitting load was proposed in order to develop an optimization technique of a warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, thermal-structural coupled field analysis. Actual loads measured in the field have a good agreement with the results obtained from theoretical and finite element analysis and also the expanded amounts of the outer diameters of the gears have a good agreement with the results.

• 한국정밀공학회지
• /
• 제23권5호
• /
• pp.37-43
• /
• 2006

Fitting process carried out in automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that heats gear to a suitable range under the tempering temperature and squeezes it toward the outer diameter of shaft. Its stress depends on the yield strength of gear. Press fitting is a method that generally squeezes gear toward that of shaft at room temperature by press. Another method heats warmly gear and safely squeezes it toward that of shaft. Warm shrink fitting process for automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by this process produced dimensional change in both outer diameter and profile of the gear. So that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of warm shrink fitting process, in which design parameters are involved; contact pressure according to fitting interference between outer diameter of shaft and inner diameter of gear, fitting temperature, and profile tolerance of gear. In this study, an closed form equation to predict contact pressure and fitting load was proposed in order to develop optimization technique of warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, that is, thermal-structural coupled field analysis. Actual loads measured in the field have a good agreement with the results obtained by theoretical and finite element analysis and also the expanded amounts of the outer diameters of the gears have a good agreement with results.