• 동아시아식생활학회지
• /
• 제23권6호
• /
• pp.713-722
• /
• 2013

The purpose of this study was to examine the effects of dietary green tea powder supplementation on bone metabolism in streptozotocin-induced diabetic rats. Thirty-two male Sprague-Dawley rats (body weight $210{\pm}3g$) were divided into two groups, diabetic and non-diabetic groups. Each group was randomly divided into two subgroups which were fed with the control and 1% green tea powder diets. The serum and urine concentrations of calcium and phosphorus were determined. Serum osteocalcin and ALP and urinary DPD crosslinks value were measured in order to monitor bone formation and resorption. Bone mineral density (BMD) and bone mineral content (BMC) were estimated using PIXImus in the spine and femur. Body weight gain and FER were lower in the diabetic group than in the non-diabetic group regardless of diets. The serum concentration of calcium and phosphorus were not changed among all groups. Urinary calcium and phosphorus excretion were higher in the diabetic group than in the non-diabetic group regardless of diets; however, they were not significantly different by green tea powder intake. Serum alkaline phosphatase (ALP) was increased in the diabetic group than in thenon-diabetic group. Further, there were no significant differences in serum osteocalcin and urinary deoxypyridinoline crosslinks value among all groups. The levels of spine and femur bone mineral density of the diabetic group were significantly lower than that of the non-diabetic group. Within the diabetic group, spine BMD was significantly higher in rats fed with the green tea powder diet than in rats fed the control diet. Therefore, this study suggests that green tea powder has a beneficial effect on bone health, although it is not directly applicable to humans.

• Bulletin of the Korean Chemical Society
• /
• 제31권9호
• /
• pp.2531-2536
• /
• 2010

Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have been employed to investigate the molecular structures and absorption spectra of two dyes containing diphenylaniline and 4-diphenylamino-diphenylaniline as donor moiety (TPA1 and TPA3). The geometries indicate that the strong conjugation is formed in the dyes. The electronic structures suggest that the intramolecular charge transfer from the donor to the acceptor occurs, and the electron-donating capability of 4-diphenylamino-diphenylaniline is stronger than that of diphenylaniline. The computed highest occupied molecular orbital (HOMO) energy levels are -5.31 and -4.90 eV, while the lowest unoccupied molecular orbital (LUMO) energies are -2.29 and -2.26 eV for TPA1 and TPA3, respectively, revealing that the interfacial charge transfer between the dyes and the semiconductor electrode are electron injection processes from the photon-excited dyes to the semiconductor conduction band. Furthermore, all the experimental absorption bands of TPA1 and TPA3 have been assigned according to the TDDFT calculations.

• 한국자원식물학회지
• /
• 제28권2호
• /
• pp.271-278
• /
• 2015

생강연작재배지 토양에 녹비작물의 재배가 토양 양분의 변화와 뿌리썩음병원균 경감효과를 알기위해 헤어리베치, 크림손클로버, 오차드글라스를 80일간 재배 후, 토양에 환원하여 토양분석 및 real-time PCR 분석한 결과는 다음과 같다. 녹비작물의 생육은 크림손클로버가 가장 좋았으며, 질수흡수량은 크림손클로버가 가장 높게 나타났으며, 토양의 인산함량은 오차드글라스가 가장 낮게 나타났다. T-N 함량은 헤어리벳치 > 크림손클로버 > 오차드글라스 순으로 나타났다. 또한 토양 내 뿌리썩음 병원균 밀도분석을 위해 Pythium zingiberum 균 특이 5.8S rDNA를 이용하여 real-time PCR 분석한 결과 헤어리베치, 오차드그라스 및 크림손클로버 처리의 Ct값은 대조구보다 낮게 나타났다. 이상의 결과를 요약해볼 때 생강연작재배지에서 녹비처리 후 토양은 대조구에 비해 EC가 감소되고, 몇 몇 무기성분은 증가하였으며, 뿌리썩음 병원균 밀도는 감소하였다.

• 생태와환경
• /
• 제34권2호통권94호
• /
• pp.81-89
• /
• 2001

녹색 유글레나조류와 수환경 요인과의 상호 관계를 규명하기 위하여, 전주시내 도심 하천에서 1996년 9월부터 1997년 8월가지 유글레나조류의 종조성과 밀도 및 환경요인을 매월 조사하였다. 질산염 농도는 6월에 3.22 mg/l로 높았고, 인산염은 겨울철에 0.71 mg/1 이상으로 높았다. 녹색 유글레나조류는 5속 71종이 출현하였으며, 봄에서 초여름 사이에 35${\sim}$42종으로 높고, 겨울에는 20종 이하였다. 출현종 수는 수온과는 정의 상관관계를 보여주었다. 녹색 유글레나조류의 밀도는 겨울과 초여름에 각각 최대가 되는 전형적인 bimodal형을 보여주었다. 겨울의 밀도는 5,394 ce11s/ml로, Euglena caudata, E. geniclata와 E. viridis의 활발한 생장에 기인하였으며, 인산염에 정의 상관관계를 보였다. 초여름의 밀도는 4,823 cells/ml로 E. deses, Lepocinclis ovum과 Phacus trypanon등의 활발한 생장에 기인하며, 암모늄염과 질산염에 정의 상관을 보였다. 녹색 유글레나조류의 생태적 특징은 전주천과 같이 오염된 수계에서 환경요인의 변화를 예측하는 생물학적 자료로 활용할 수 있다.

• 한국응용곤충학회지
• /
• 제40권1호
• /
• pp.44-49
• /
• 2001

진딧물류 천적 혹파리(Aphidoletes aphidimyza (Rondani))의 온도별 발육 및 복숭아혹진딧물에 대한 포식특성을 실험실 및 온실 조건에서 조사하였다. 온도와 유충의 발육속도와의 상관 을 구하였으며 ((regression; development rate (y) : 0.013348x (temperature)-0.173022, F = 41.14, p<0.01)), 발육영점온도는 $13^{\circ}C$이었다. $\25pm$2$^{\circ}C$ 에서 유충 발육기간은 5.3일 이었고, 1세대기간은 29 일이었다. 복숭아혹진딧물 밀도에 따른 혹파리의 포식량은 arena(직경 9cm)당 복숭아혹진딧물 10마리일 때 4마리를 포식하여 포화상태를 나타냈다. 온실조건에서 진디혹파리의 진딧물 포식은 지체적밀도의존반응과 유사한 반응을 보였다.

• Advanced Composite Materials
• /
• 제16권4호
• /
• pp.377-384
• /
• 2007

'Green' composites were fabricated from poly lactic acid (PLA) and bamboo fibers by using a conventional hot pressing method. The insulating properties of the PLA-bamboo fiber 'green' composites were evaluated by determination of the thermal conductivity, which was measured using a hot-wire method. The thermal conductivity values were compared with theoretical estimations. It was demonstrated that thermal conductivity of PLA-bamboo fiber 'green' composites is smaller than that of conventional composites, such as glass fiber reinforced plastics (GFRPs) and carbon fiber reinforced plastics (CFRPs). The thermal conductivity of PLA-bamboo fiber 'green' composites was significantly influenced by their density, and was in fair agreement with theoretical predictions based on Russell's model. The PLA-bamboo fiber composites have low thermal conductivity comparable with that of woods.

• 한국세라믹학회지
• /
• 제31권1호
• /
• pp.31-38
• /
• 1994

To overcome the demerit of conventional forming method, new forming method, pressureless powder packing forming method, was investigated. This technique is performed by powder packing followed by the infiltration of binder solution. Various alumina powders were used as starting materials and the powders showing good packing condition through powder packing experiment were chosen. The green densities prepared by this new forming method with these powders were lower than those of specimens by pressing method, but, nearly same density was obtained in case of green body prepared with the powders having high packing density. The distribution of binder in a green body was homogeneous and it was possible to a complex shape form by this forming method.

• 아시안잔디학회지
• /
• 제23권2호
• /
• pp.287-294
• /
• 2009

본 연구는 식물생장조절제 Trinexapac-ethyl을 골프장에 사용한 후 하절기 크리핑 벤트그래스에서 나타나는 생육특성을 파악해, 골프장 코스관리의 기초자료를 제공하고자 수행되었으며 그 결과, 잔디 밀도는 Trinexapac-ethyl 처리 후 대조구에 비해 밀도는 평균 1.7개($cm^2$) 높았으며, 생육조건이 좋지 않은 6월부터 7월 사이에는 평균 2개($cm^2$)이상 높아, 여름철 밀도의 차이가 컸다. 뿌리길이는 대조구에 비해 평균 0.3cm 길게 나타났으며, 6월과 8월을 제외하면 나머지 기간 동안 뿌리 길이의 유의적인 차이는 없었다. 시각적 품질의 차이는 매우 컸는데, 시험 기간 내내 대조구에 비해 유의적으로 높은 품질을 유지하였으며, 특히 장마철과 고온기에도 대조구에 비해 하고현상이 적게 발생되어, trinexapac-ethyl에 의한 고온 스트레스 경감 효과가 있을 것으로 분석되었다. 그린스피드의 차이는 조사 시간 내내 큰 유의차를 보였으며, 특히 벤트그래스 생육에 불리한 6월 말부터 7월 중순까지는 생장조절제에 의한 그린스피드 효과가 더 크게 나타났다. 이상의 결과를 통해, 잔디 생육이 왕성한 봄부터 크리핑 벤트그래스에 생장조절제를 주기적으로 처리 할 경우, 잔디 밀도와 시각적 품질이 개선되고 그린스피드도 빨라져 관리가 힘든 장마철과 여름철 그린관리에 매우 효과적이라는 사실을 알게 되었다. 향후에는 농약 및 비료와의 혼용가능성에 대한 연구가 수행될 예정이며, 생장조절제 trinexapac-ethyl의 다음 해 봄철 그린-업에 미치는 영향에 대한 연구도 수행될 예정이다.

• 대한원격탐사학회지
• /
• 제38권4호
• /
• pp.421-434
• /
• 2022

Fine particulate matter (PM2.5) has been the biggest environmental problem in Korea since the 2010s. The present study considers the value of urban forests and green infrastructure as an ecosystem service (ES) concept for PM2.5 reduction based on satellite and spatial data, with a focus on Seoul, Korea A method for the spatial ES assessment that considers social demand variables such as population and land price is suggested. First, an ES assessment based on natural environment information confirms that, while the vitality of vegetation is relatively low, the ES is high in the city center and residential areas, where the concentration of PM2.5 is high. Then, the ES assessment considering social demand (i.e., the ESS) confirms the existence of higher PM2.5 values in residential areas with high population density, and in main downtown areas. This is because the ESS of urban green infrastructure is high in areas with high land prices, high population density, and above-average PM2.5 concentrations. Further, when a future green infrastructure improvement scenario that considers the urban forest management plan is applied, the area of very high ESS is increased by 74% when the vegetation greenness of the green infrastructure in the residential area is increased by only 20%. This result suggests that green infrastructure and urban forests in the residential area should be continuously expanded and managed in order to maximize the PM2.5 reduction ES.

• 한국분말재료학회지
• /
• 제24권5호
• /
• pp.400-405
• /
• 2017

The addition of a large amount of alloying elements reduces the compactibility and increases the compacting pressure, thereby shortening the life of the compacting die and increasing the process cost of commercial PM steel. In this study, the characteristic changes of Fe-Mo-P, Fe-Mn-P, and Fe-Mo-Mn-P alloys are investigated according to the Si contents to replace the expensive elements, such as Ni. All compacts with different Si contents are fabricated with the same green densities of 7.0 and $7.2g/cm^3$. The transverse rupture strength (TRS) and sintered density are measured using the specimens obtained through the sintering process. The sintered density tends to decrease, whereas the TRS increases as the Si content increases. The TRS of the sintered specimen compacted with $7.2g/cm^3$ is twice as high as that compacted with $7.0g/cm^3$.