• 한국환경복원기술학회지
• /
• 제14권4호
• /
• pp.41-54
• /
• 2011

Tree roots can enhance soil shear strength and slope stability. However, there has been a limited study about root reinforcement of major tree species in Korea because of some experimental difficulties. Thus, this study was conducted to analyze the performance of Japanese larch (Larix kaempferi) and Korean pine (Pinus koraiensis) which are two common plantation species in Korea. Profile wall method was used to measure the spatial distribution of root system and its diameter within 15 soil walls of Japanese larch stand and 13 soil walls of Korean pine stand in Taehwa University Forest, Seoul National University, Korea. Root tensile properties of each species were assessed in the laboratory, and root reinforcements were estimated by Wu model. The study observed that the number and cross-sectional area (CSA) of root in both species could tend to decrease with soil depth. Especially, CSA were well-fitted to exponential functions of soil depth. Mean root area ratios (RAR) were 0.03% and 0.10% for Japanese larch and Korean pine, respectively. Estimated root reinforcement from Wu model were, on the average, 4.04 kPa for Japanese larch and 12.26 kPa for Korean pine. Overall, it was concluded that root reinforcement increased the factor of safety (Fs) of slope for small-scale landslide as the result of two-dimensional (2-D) infinite slope stability analysis considering vegetation effects.

• 한국산학기술학회논문지
• /
• 제15권2호
• /
• pp.688-697
• /
• 2014

우리나라 장기요양기관은 노인복지법 적용 기관과 미적용 기관이 혼재되어 사회복지법인재무회계규칙이나 장기요양보험법의 지침을 따르고 있다. 그러나 시설정보시스템의 이용이 불가능한 경우도 있고 자료 제출의 강제적 의무도 없어 장기요양기관의 재무상태와 경영실태와 관련된 신뢰성있는 회계정보는 부족한 실정이다. 따라서 본 연구에서는 현재 회계 관련 규정의 문제점과 개선방향을 알아보고 회계기준 정립을 위한 방안을 제시하였다. 본 연구에서는 장기요양기관의 실태를 반영하여 단기적으로는 복식부기기준의 회계기준과 단식부기 기준의 두 가지 회계기준이 필요할 뿐 만 아니라 적정한 재무보고를 위해 회계원칙에 부합하는 세 가지의 이익처분항목을 도입하였다. 마지막으로 충당부채 계정의 도입과 국고보조금, 감가상각비 등에 대한 회계 기준을 도입하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 추계학술대회 논문집
• /
• pp.307-308
• /
• 2007

This work shows the experimental results obtained from ageing at a temperature of 100 C for 48, 70 and 312 h, although the application of AC electrical tension in samples and the measuring of current leakage are presented. The measurements in samples were carried out with samples prepared from the deformulated commercial materials and respectively reformulated into thin films. The obtained results showed the mechanisms of conduction of samples in low and high electric fields. It was also identified an electric tension transition showing that in low fields it prevails the Ohm's law conduction, and in high electric fields it prevails the conduction of space charge limited current (SCLC). These results can support the natural rubber formulation process having as their main objective the reducing of the mechanisms that occur under high conduction current in high electric fields, which leads the material to a dielectric breakdown. Raw Natural rubber in Brazil is extracted from rubber trees (Hevea brasiliensis) in farms in So Paulo State by using some new plantation technology in smaller spaces, with trees placed a few meters from each other. In the Amazon rain forest the rubber trees are found naturally and their spacing may be of hundreds of meters or even kilometers between them. It is necessary to research this raw material from different internationally standard clones to characterize dielectric and electric properties for industrial applications. Moreover, this natural material has a low commercial price when compared to the synthetic ones.

• 농촌계획
• /
• 제12권4호
• /
• pp.115-123
• /
• 2006

The direct payment program for rural landscape conservation in practice since 2005. Recently it is the policy or plan of direct payment for rural landscape conservation attracts great interests as they may help rural people who are very disadvantaged. This paper presents the status of the direct payment program for landscape conservation in rural area and proposed improvements to the program as following; 1) to diversify the plant species, 2) to include other rural elements than plants, 3) to enlarge the areas of crop plantation, 4) to simplify and clarify application process. We sampled two pilot programs, one of spring flower crop and the other of autumn flower crop, and questionnaire surveyed visitors, local government officers and farmers in order to find problems and suggest improvements.

• 대한지리학회지
• /
• 제39권2호
• /
• pp.171-194
• /
• 2004

남북전쟁 이전 미국의 남부지방은 플랜테이션, 노예, 면화 등 주로 부정적인 이미지로 중서부지방과 동부지방에 대비되었다. 환금작물 생산에 특화된 남부의 농업은 제조업 중심의 동부나 곡창지대를 안고있는 서부와는 확연한 차이를 보이는데, 이들 세 지역의 교역관계를 분석한 더글라스 노스는 남부지방의 경우 지역내부에서 소비되는 식량은 전적으로 서부에서 수입하였다고 설명하였다. 그러나 수집된 각종 통계와 문헌상의 기록으로 미루어 남부는 적어도 1830년대 말에서 1840년대 초에 자체적으로 충분한 양의 식량을 확보하기에 이른다. 그리고 그렇게 될 수 있었던 데에는 다년간의 면화재배로 척박해진 토양을 개선하기 위해 농촌지식인이 중심이 되어 범지역적으로 전개한 ‘과학적 영농’ 운동의 역할이 컸다. 새롭게 보급된 다각적 농법에서는 윤작이 강조되었는데, 특히 옥수수, 면화, 콩의 돌려짓기가 널리 채택되었다. 이를 통해 주요 식량원인 옥수수의 자급이 가능해졌고, 남아도는 양은 단백질 공급원인 돼지의 사료로 활용할 수 있었으며, 면화재배에서 얻어지는 수익도 체감의 악순환을 벗어날 수 있었다. 그러나 다각화의 가장 큰 소득이라면 질소고정에 효과적인 콩과작물을 통해 면화 단작으로 척박해진 토양을 되살릴 수 있다는 환경인식의 형성이었다.

• The Plant Pathology Journal
• /
• 제36권6호
• /
• pp.515-535
• /
• 2020

Essential oils (EOs) have gained a renewed interest in many disciplines such as plant disease control and medicine. This review discusses the components of ginger EOs, their mode of action, and their potential nanotechnology applications in controlling tropical plant diseases. Gas chromatography-mass spectroscopy (GC-MS), high-performance liquid chromatography, and headspace procedures are commonly used to detect and profile their chemical compositions EOs in ginger. The ginger EOs are composed of monoterpenes (transcaryophyllene, camphene, geranial, eucalyptol, and neral) and sesquiterpene hydrocarbons (α-zingiberene, ar-curcumene, β-bisabolene, and β-sesquiphellandrene). GC-MS analysis of the EOs revealed many compounds but few compounds were revealed using the headspace approach. The EOs have a wide range of activities against many phytopathogens. EOs mode of action affects both the pathogen cell's external envelope and internal structures. The problems associated with solubility and stability of EOs had prompted the use nanotechnology such as nanoemulsions. The use of nanoemulsion to increase efficiency and supply of EOs to control plant diseases control was discussed in this present paper. The findings of this review paper may accelerate the effective use of ginger EOs in controlling tropical plant diseases.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2012년도 학술발표회
• /
• pp.18-18
• /
• 2012

In Japan, about 67% of the land is covered by forests and about 41% of them consist of plantations. About 35% of the plantations consist of old-aged plantations of older than 50 yearsand the percentage is projected to 67% in ten years' time. Although the trees of these plantations are supposed to be cut for timber production, most of them remain unmanaged and thus overcrowded mainly due to declining domestic forest industry. Since the forests are mostly located in headwater watershed, there are growing concerns about the degradation of water resources by these unmanaged plantations. To understand the ecohydrological processes in these plantations and examine the effect of intensive 50-60 % thinning to increase infiltration rate and reduce overland flow and soil erosion by recovering understory vegetation, the JST-CREST project "Development of Innovative Technologies for Increasing in Watershed Runoff and Improving River Environment by the Management Practice of Devastated Forest Plantation (Representative: Yuichi Onda)" has been launched since 2009. The ultimate objective of this project is to provide potential scenario to enhance low flow discharge in drought period and reduce turbid material in high flow period. We have been conductingintensive field observation campaign in five research sites across Japan. In Fukuoka site, integrated ecohydrological observations have been conductedin two contrastive watersheds since 2010. Intensive 50% thinning was conducted from January to April 2012 and comparative studies of ecohydrological processes before and after thinning have been started. The interim results from all the sites of this project will be presented in the 3rd International Congress for Forest and Water in a Changing Environment held in Fukuoka during 18-20 September, 2012 (http://www.forest.kyushu-u.ac.jp/~ecohydrol/3ForestWater/index.html).

• Journal of the Korean Wood Science and Technology
• /
• 제48권1호
• /
• pp.1-11
• /
• 2020

Indonesian log production is dominated by young trees harvested from plantation forests. The timber contains of sapwood and juvenile wood, which are not resistant to termite attack. Smoking treatment can enhance wood resistance to termite attack, but it also changes the color. Specimens of mangium (Acacia mangium) and sengon (Falcataria moluccana) wood were exposed for 1, 2, and 3 weeks to smoke produced from the pyrolysis of salam (Syzygium polyanthum) wood. The color change of the wood was measured using the CIELab method. In addition, wood specimens were exposed to subterranean termites (Coptotermes curvignathus Holmgren) under laboratory conditions. Untreated and imidacloprid-preserved wood samples were also prepared for comparison purposes. The results showed that the color of smoked wood differed from that of untreated wood, and the color change for sengon was greater than for mangium. In addition, the 1-week smoking period changed the wood color less than the 2- and 3-week periods, which did not differ. Imidacloprid-preserved wood had distinctive color changes compared to untreated wood. Untreated mangium wood had moderate resistance to subterranean termite attack (resistance class III), while sengon had very poor resistance (resistance class V). Salam wood smoke enhanced wood resistance to termite attack, and smoke treatment of 1 week for mangium and 2 weeks for sengon resulted in the wood becoming very resistant (resistance class I). Both types of smoked wood were more resistant to subterranean termite attack than imidacloprid-preserved wood (average class II resistance).

• 농업생명과학연구
• /
• 제45권5호
• /
• pp.33-39
• /
• 2011

본 연구는 강원지역 1영급 금강소나무를 대상으로 천연임분과 인공임분간의 직경별 뿌리의 분포 특성을 알아보기 위해 실시하였다. 직경별 뿌리분포는 두 임분 모두 0.5-2.0 mm 직경급의 뿌리가 가장 많았고, 10.0-20.0 mm 직경급의 뿌리가 가장 적었다. 두 임분간 직경별 뿌리발달에서 5.0 mm 이하의 직경급은 인공임분이 천연임분보다 우수하였지만, 5.0 mm 이상의 직경급 발달은 천연임분이 더 우수하였다. 토양층위별 뿌리의 직경별 발달은 천연임분이 인공임분보다 다양한 토양층위에 고르게 분포하였으며, 인공임분은 5.0 mm 이하의 직경급이 토심 10 cm, 토양 수평층위 20 cm 범위 내에 편중되어 발달하였다. 따라서 임분 성립방법의 차이는 뿌리발달의 현저한 구조적 차이를 나타낼 수 있으며, 이러한 결과는 인공조림시 올바른 식재방법과 조림지침을 제공하는데 중요한 기초자료로 사용될 수 있을 것이다.

• Advances in environmental research
• /
• 제3권3호
• /
• pp.207-216
• /
• 2014

A study was conducted to determine the phytotoxic effect of mercury on seed germination and seedling growth of an important arid legume tree Albizia lebbeck. The seeds germination and seedling growth performance of A. lebbeck responded differently to mercuric chloride treatment (1 mM, 3 mM, 5 mM and 7 mM) as compared to control. Seed germination of A. lebbeck was significantly (p < 0.05) affected by mercury treatment at 1 mM. Root growth of A. lebbeck was not significantly affected by mercury treatment at 1 mM, and 3 mM. Shoot and root length of A. lebbeck were significantly (p < 0.05) affected by 5 mM concentration of mercury treatment. Increase in concentration of mercury treatment at 5 mM and 7 mM significantly (p < 0.05) reduced seedling dry weight of A. lebbeck. The treatment of mercury at 1 mM decreased high percentage of seed germination (22%), seedling length (10%), root length (21.85%) and seedling dry weight (9%). Highest decrease in seed germination (51%), seedling (34%), root length (48%) and seedling dry weight (41%) of A. lebbeck occurred at 7 mM mercury treatment. A. lebbeck showed high percentage of tolerance (78.14%) to mercury at 1 mM. However, 7 mM concentration of mercury produced lowest percentage of tolerance (51.65%) in A. lebbeck. The seed germination potential and seedling vigor index (SVI) clearly decreased with the higher level of mercury. Plantation of A. lebbeck in mercury-polluted area will help in reducing the burden of mercury pollution. A. lebbeck can serve better in coordinating in land management programs in metal contaminated areas. The identification of the toxic concentration of metals and tolerance indices of A. lebbeck would also be helpful for the establishment of air quality standard.