• Journal of Korean Society of Forest Science
• /
• v.99 no.1
• /
• pp.68-74
• /
• 2010

The present study was conducted to investigate growth performance and ascorbic acid contents of Allium victorialis var. platyphyllum, Ligularia fischeri, and L. stenocephala growing under four different light intensity regimes (full sun, and 64~73%, 35~42%, 9~16% of full sun). The leaf area and total biomass of Allium victorialis var. platyphyllum were highest in 35~42% of the full sun. However, the leaf area and total biomass were highest in 64~73% of the full sun in Ligularia fischeri, and L. stenocephala. The leaf thickness decreased with increasing shading in all three wild vegetables. The growth of root comparing to that of shoot decreased as shading increased, and as the result, the ratio of shoot biomass to root biomass increased. Ascorbic acid contents were higher in Allium victorialis var. platyphyllum than in Ligularia fischeri and L. stenocephala. Allium victorialis var. platyphyllum showed the highest contents of ascorbic acid in 35~42% of full sun. Whereas Ligularia fischeri and L. stenocephala showed the highest in 64~73% of full sun.

• Journal of the Korean Vacuum Society
• /
• v.19 no.6
• /
• pp.460-466
• /
• 2010

We measured the magnetic properties of stainless steels type 304 and 316L to see if those materials can be used for the applications where non-magnetic materials are required. The results show that the relative permeability of samples was greatly increased during manufacturing processes. After full solution annealing, however the permeability could be reduced to less than 1.02. Thus, the materials may be employed in the low-permeability applications.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.6
• /
• pp.497-504
• /
• 2009

The characteristic changes in weight, moisture content, and dimension at the early adsorptiondesorption stage of PEG-treated Korean pine (Pinus koraiensis), Japanese larch (Larix kaempferi), mongolian oak (Quercus mongolica) and sargent cherry (Prunus sargentii) woods were investigated. The wood samples were treated with PEG 1000, 2000 and 4000, and conditioned at the relative 98%, 65% and 20% for humidities of one week. The weight of Korean pine, Japanese larch and sargent cherry woods treated with PEG 1000 and 2000 during the adsorption-desorption was significantly changed, but mongolian oak was slightly changed. Moisture content was highly Moisture content was highly fluctuated by the change of relative humidity in the three species except oak wood. Although the weight of PEG-treated wood; however, changes in dimension could be prevented by PEG treatment in all species tested.

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.6
• /
• pp.721-731
• /
• 2019

Air drying depends on species, density, dimension of wood, the geographical location of the air drying yard, and the meteorological factors of air drying site. If there are four seasons with large difference in temperature and humidity like in Korea, the research of the meteorological factors is required in air drying site. In this study, effective air drying days (EADD) of 24 regions in Korea were calculated by using the average monthly temperature, relative humidity, and wind speed. The EADD in 24 regions in Korea was ranged from 239 days to 291 days, with an average 265 days. This result is 5 days increased compared to the average of EADD calculated using the meteorological factors from 1955 to 1984. The results of multiple regression analysis on the EADD and meteorological factors showed that EADD affected in the order of temperature, relative humidity, and wind speed. As a result of dividing Korea into 4 zones of EADD, the zones of EADD were moved northward compared to previous study due to global warming. As basic data for predicting the moisture content (MC) distribution of Korean red pine logs during air drying conducted in Seoul, the average monthly temperature, relative humidity and wind speed for three years from 2016 to 2018 were presented, and the corresponding changes of the equilibrium MC were analyzed.

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.6
• /
• pp.732-750
• /
• 2019

Air drying was carried out on 15 Korean red pine logs to provide a prediction model of the moisture content (MC) change in the wood during drying. The final MC was 17.4% after 880 days since the beginning of air drying in the summer for 6 Korean red pine logs with 68.7% initial MC. The final MC was 16.0% after 760 days since the beginning of air drying in the winter for 9 Korean red pine logs with 35.8% initial MC. A regression model with R-squared of 0.925 was obtained as a result of multiple regression analyses with initial MC, top diameter, temperature, relative humidity, and wind speed as independent variable and and MC change during air drying as dependent variable. The initial MC and top diameter, which is the characteristic of Korean red pine, have greater effect on the MC decrease during air drying compared to meteorological factors such as the temperature, relative humidity, and wind speed. Two-dimensional mass transfer analysis was performed to predict the MC distribution of Korean red pine logs during air drying. Two prediction models with different air drying days and different meteorological factors for the determination of the diffusion coefficient and surface emission coefficient were presented. The error between the different two methods ranged from 0.1 to 0.8% and the difference from the measured value ranged from 2.2 to 3.6%. By measuring the internal MC during air drying of Korean pine logs with various initial MC and diameter, and calculating the moisture transfer coefficient in wood for each meteorological condition, the error of the prediction model can be reduced.

• Korean Journal of Food Science and Technology
• /
• v.21 no.2
• /
• pp.203-211
• /
• 1989

During hot air drying of root vegetables such as radish and sweet potatoes, shrinkage and casehardening occurred, and thereby the quality change appeared. Therfore the hot air drying apparatus in which air temperature, relative humidity and air velocity could be controlled was designed, and the drying and shrinking characteristics of radish and sweet potatoes were studied. Also the external factors that affected these characteristics were investigated. The whole drying process of radish and sweet potatoes could be divided into four different drying rate periods, namely constant rate period, first falling rate period, second falling rate period (a) and (b). The shrinking rate curve consisted of four periods nearly corresponding to drying rate periods. The shrinking rate slowly increased in the constant rate period, rapidly increased in the first falling rate period, and reached the highest value in the early period of the second falling rate period. The surface shrinkage was greatly affected by the thickness of sample, relative humidity and initial moisture content. The shrinking ratio was increased with decreasing thickness and increasing relative humidity and initial moisture content.

• Journal of Mushroom
• /
• v.9 no.1
• /
• pp.34-38
• /
• 2011

In this study, temperature and relative humidity during growth of fruit body were applied to oyster mushroom (Pleurotus ostrestus) to elucidate the prolongation effect of storage. Although there were not big differences among conditions of cultivation, weight loss and change of pileus color were slight increased and hardness and springness of fruit body were little decreased with storage period. When whole mushrooms (250~300g) were packaged with wrap and stored at $4{\pm}1^{\circ}C$, the shelf life of the oyster mushrooms were cultivated at $16^{\circ}C$ and at $13^{\circ}C$ was 18 day and 24days, respectively. Therefore, it was elucidated that the treatment of low-temperature at the step of fruit body development affected extension of shelf life in oyster mushroom.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.17 no.2
• /
• pp.25-30
• /
• 2013

Purpose: To evaluate kidney function, renal relative uptake is very important and is affected by kidney and the setting of background region of interest (ROI). In particular, in the case of patients with hydronephrosis to the naked eyes, such as size, position and shape etc. can be difficult to identify. So according to ROI to be set by user, the results are many differences. This study assumes the ROI of a constant kidney. According to the change of background ROI by analyzing renal relative uptake affect how the results are intended to study. Materials and Methods: From January 2012 to February 2013, we analyzed 27 patients with hydronephrosis who were examined MAG3 test in nuclear medicine department of Samsung medical center. After patients were received intravenous injection of $^{99m}Tc-MAG3$ 185 MBq (5 mCi) data were obtained. While we reconstructed images of patients, we've changed background ROI in the process of setting up ROI. First, in the process of renal processing, automatic ROI which set automatically and background ROI which needed to set manually were compared. Second, we set the ROI position separated by above, lateral and bottom of kidney. Third, background setting time were compared with 1-2 min and 2-3 min. Results: The relative uptake occurred in 3.7%p of the errors on average in Automatic & Manual ROI study. And comparison of background ROI position study, located in the lower position was more accurate results. Above, lateral, bottom each of the values 74.6%, 67.6% and 62.0% showed respectively. The standard value was 59.9%. finally, split function range test doesn't show significant difference. Conclusion: The study shows that relative uptake of kidney is affected in the background ROI. Therefore, it should be set by considering various dependent factors.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2008.11a
• /
• pp.127-130
• /
• 2008

가시광선에서 활성을 보이는 TiO$_2$광촉매를 이용하여 대표적인 휘발성유기화합물질들 중에 하나인 TCE의 분해을에 대한 실험을 수행하였다. 본 연구에서 여러 가지 변수들 중에 농도와 상대습도에 따른 휘발성유기화합물의 분해율에 대하여 실험하였으며, 농도 및 상대습도의 변화에 따른 분해율의 영향에 대하여 확인 할 수 있었다. 향후 광촉매를 실제 실내대기에 적용하기 위해 더욱 다양한 조건에서 여러 가지 오염물질에 대한 연구들이 진행되어야 할 것이다.

• Food Science and Preservation
• /
• v.10 no.3
• /
• pp.297-301
• /
• 2003

The hardness of corrugated packaging box decreased during storage period because of high humidity. Therefore, the strength-decreasing factor of corrugated packaging box had to be investigated to determine the compression strength of the corrugated packaging box. This study was conducted to define the characteristics of moisture absorption as well as compression strength of corrugated fiberboard. (1) The moisture content of the corrugated fiberboard was rarely influenced by the kinds of raw materials and water repellent. However, the moisture adsorption of the corrugated fiberboard was shown to be clearly affected by air temperature changes. (2) The moisture content of the corrugated fiberboard was significantly affected by relative humidity. The moisture adsorption of corrugated fiberboard was also greatly influenced by composition of raw materials rather than water repellent. The results indicated that the improvement of raw materials was more effective than the increase of water repellent of corrugated fiberboard to reduce the moisture adsorption of the corrugated fiberboard. (3) The vertical compression strength was significantly decreased with increasing relative humidity. The reduction rate of vertical compression strength was not charged with the increase of relative humidity, which was regardless of kinds of corrugated fiberboard. (4) For improving the strength of the corrugated packaging box, new technique should be found to develop better quality of raw materials. Moreover, the physical construction of corrugated packaging box should be clearly understood because the corrugated packaging box for the agricultural products was usually used for the circumstances of high humidity and low air temperature