• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.154-161
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• 1992

This experiment was carried oui to determine the relativeness between growth, yield characters and bio-informations as influenced by the spray and rest time intervals of nutrient solution. Tomato(Lycopersicon esculentum Mill.) were grown in aeroponic system on a misting schedule of continuously 60 sec, 30 sec and 10 sec at 10 min intervals with full strength Yamazaki's solution recommended for tomato production. The results obtained were as follows : 1. Leaf area was highest in the plot of 30 sec spray and 10 min rest while the forest one was the plot of 60 sec spray and 10 min rest. Growth characteristics in terms of dry weight of each organ, number of flower, number of flower setted and fruit dry weight were greater in the plot of 30 sec spray and 10 min rest than the other treatments. 2. The number of flower increased with decreasing dry weight but number of flower sorted was not significantly different among treatment except for the plot of 60 sec spray and 10 min rest. 3. Leaf dry weight and fruit dry weight were highly correlated so that 30 sec spray and 10 min rest plot which is the highest fruit dry weight showed the largest leaf area. Continuously sprayed plot reduced markedly the fruit dry weight compared with leaf area. Optimum spray and rest time of nutrient solution in the range of this experiment was determined as 30 sec spray and 10 min rest. 4. Solar radiation within glasshouse during daytime reduced severely compared with outdoor one and air temperature within greenhouse was higher than the leaf temperature of tomato plant. The changes of environmental factors, solar radiation, temperature were accompanied with the sensitive change of bio-informations of tomato leaf Especially differences of spray intervals of nutrient solution affected greatly to the changes of bio-informations : leaf water potential, stomatal resistance and leaf temperature etc. 5. The changing patterns of leaf growth as influenced by the spray and rest intervals of nutrient solution were closely related to the leaf water potential, stomatal resistance and leaf temperature. Feasibility was demonstrated that measurement of bio-information of tomato leaf as influenced by the change of environmental factors could be expected to the amount of growth and fruit yield.

• Journal of Bio-Environment Control
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• v.12 no.3
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• pp.152-159
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• 2003

This study was conducted to analyze the water consumption in closed transplants production system (CTPS) for the production of quality transplants and to investigate the effect of relative humidity on the water balance in CTPS. Potato (Solanum tuberosum L. cv. Dejima) plug seedlings were grown for 15 days at air temperature of 20$^{\circ}C$, relative humidity of 70%, photoperiod of 16/8 h, and photosynthetic photon flux (PPF) of 200 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-l}$ following rooting for 5 days in CTPS. Amount of humidified, dehumidified, irrigated and evapotranspirated water were 67.9 kg${\cdot}m^{-2},\;196.9{\cdot}m^{-2},\;44.3\;kg{\cdot}m^{-2},\;33.5\;kg{\cdot}m^{-2}$, respectively. Water content of media and plants were 1.2 kg${\cdot}m^{-2},\;6.9\;kg{\cdot}m^{-2}$, respectively. Three relative humidity levels of 60, 70, and 80% were provided to analyze the effect of humidity on the water balance in CTPS. Amount of humidified, dehumidified, irrigated, evapotranspiratad water and water contents of media and plants increased with increasing relative humidity. Since the water consumption required to produce plug seedlings in CTPS dec1eased with decreasing relative humidity, the available water utilization efficiency of CTPS increased with decreasing relative humidity. CTPS showed high available water utilization efficiency of 0.92 - 0.97 if dehumidified water in CTPS was recycled. The development of CTPS with recycling system of dehumidified water will not only reduce the water consuming for the production of transplants but contribute to the establishment of plant production economizing in water consumption.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.659-667
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• 2000

Quality attributes of fresh-cut green onion(Allium fistulosum L.) as affected by rinsing and packaging were investigated in terms of flesh weight, color, viable cell counts, sensory properties during storage at $10^{\circ}C$. Fresh green onions were trimmed, cut, and rinsed with cold water(approximately $5^{\circ}C$) as well as chlorine solution(100 mg/L) and then packaged in low density polyethylene film pouches of $63\;{\mu}m$ thickness. Rinsing treatments with cold water or chlorine solution did not significantly influence changes in microbial populations but sensory characteristics, resulting in cut green onions of better visual quality as compared to the control without rinsing. Fresh-cut green onions were also rinsed with cold water and packaged in sealed bags of low density polyethylene films with different thickness(22, 36, $63\;{\mu}m$), and stored at $10^{\circ}C$ for 18 days. Thickness of polyethylene film was a significant factor for microorganisms populations and sensory attributes. Mesophilic aerobic bacterial count after 13 days for the control, packed in punched film bags, was $3.07{\times}10^6}$ CFU/g, while those for samples in hermetically sealed bags ranged only $1.74{\sim}2.02{\times}10^5}$ CFU/g. Gas composition within the sealed packages changed from normal air to about $1.3{\sim}5.4%\;O_2$ and $4.0{\sim}8.0%\;CO_2$ after 13 days of storage. Particularly, the visual sensory quality of cut green onion samples was retained better in polyethylene film bags of $63\;{\mu}m$ thickness(gas transmission rate: 600 $O_2\;mL/day{\cdot}m^2{\cdot}atm;\;2,500\;CO_2\;mL/day{\cdot}m^2{\cdot}atm$) than in the others.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.218-223
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• 2016

The calculation method of ground heat exchange in greenhouses has different ideas in each design standard, so there is a big difference in each method according to the size of greenhouses, it is necessary to establish a more accurate method that can be applied to the domestic. In order to provide basic data for the formulation of the calculation method of greenhouse heating load, we measured the soil temperature distribution and the soil heat flux in three plastic greenhouses of different size and location during the heating period. And then the calculation methods of ground heat exchange in greenhouses were reviewed. The soil temperature distributions measured in the heating greenhouse were compared with the indoor air temperature, the results showed that soil temperatures were higher than room temperature in the central part of greenhouse, and soil temperatures were lower than room temperature in the side edge of greenhouse. Therefore, it is determined that the ground heat gain in the central part of greenhouse and the perimeter heat loss in the side edge of greenhouse are occurred, there is a difference depending on the size of greenhouse. Introducing the concept of heat loss through the perimeter of building and modified to reflect the size of greenhouse, the calculation method of ground heat exchange in greenhouses is considered appropriate. It was confirmed that the floor heat loss measured by using soil heat flux sensors increased linearly in proportion to the temperature difference between indoor and outdoor. We derived the reference temperature difference which change the direction of ground heat flow and the perimeter heat loss factor from the measured heat flux results. In the heating design of domestic greenhouses, reference temperature differences are proposed to apply $12.5{\sim}15^{\circ}C$ in small greenhouses and around $10^{\circ}C$ in large greenhouses. Perimeter heat loss factors are proposed to apply $2.5{\sim}5.0W{\cdot}m^{-1}{\cdot}K^{-1}$ in small greenhouses and $7.5{\sim}10W{\cdot}m^{-1}{\cdot}K^{-1}$ in large greenhouses as design standard data.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.231-238
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• 2018

Chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings as affected by photosynthetic photon flux (PPF) of LED lamps were analyzed in this study. Four PPF levels, namely 25, 50, 100, $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ were provided to investigate the effect of light intensity on the chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings. Air temperature, relative humidity, and photoperiod for graft-taking were maintained at $25^{\circ}C$, 90%, $16h{\cdot}d^{-1}$, respectively. Maximum quantum yield (Fv/Fm) of rootstock as affected by PPF was found to be 0.84-0.85 and there was no significant change in Fv/Fm. Even though Fv/Fm of scion measured at 2 days after grafting was lowered to 0.81-0.82, after then it gradually increased with increasing PPF. At 4 days after grafting, the chlorophyll content extracted from scion increased with increasing PPF. Graft-taking ratio of grafted cucumber seedlings was 90-95% as PPF was ranged from $25{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ to $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. However, the graft-taking ratio of grafted seedlings healed under PPF of $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was decreased to 80%. Maximum PPF measured required for smooth joining of rootstock and scion was assumed to be $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. At healing stage of grafted cucumber seedlings, Fv/Fm of scion decreased and at least two days after grafting were required for rooting of grafted seedlings. Chlorophyll fluorescence response of rootstock and scion was linked to light irradiation. Therefore, it was concluded that physical environment including light and humidity during healing process of grafted seedlings should be controlled more precisely to facilitate root formation and to prevent scion from lowering Fv/Fm. Further studies are required to investigate the effects of root development and joining of vascular bundles of grafted seedlings on the chlorophyll content of scion.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.55-61
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• 2009

Recently, the number of high-rise buildings being built in Korea by major construction companies for residential and commercial use has been increasing. When constructing a high-rise building, it is necessary to apply massive amounts of concrete to form a mat foundation that can withstand the huge load of the upper structure. However, it is of increasing concern that due to limitations in terms of the amount of placing equipment, available job-sites and systems for mass concrete placement in the construction field, it is not always possible to place a great quantity of concrete simultaneously in a large-scale mat foundation, and for this reason consistency between placement lift cannot be secured. In addition, a mat foundation Is likely to crack due to the stress caused by differences inhydration heat generation time. To derive a solution for these problems, this study provides test results of a hydration heat crack reduction method by applying placement lift change and setting time control with a super retarding agent for mass concrete in a large-scale mat foundation. Mock-up specimens with different mixtures and placement liftswere prepared at the job-site of a newly-constructed high-rise building. The test results show that slump flow of concrete before and after adding the super retarding agent somewhat Increases as the target retarding time gets longer, while the air content shows no great difference. The setting time was observed to be retarded as the target retarding time gets longer. As the target retarding time gets longer, compressive strength appears to be decreased at an early stage, but as time goes by, compressive strength gets higher, and the compressive strength at 28 days becomes equal or higher to that of plain concrete without a super retarding agent. For the effect of placement lift change and super retarding agent on the reduction of hydration heat, the application of 2 and 4 placement lifts and a super retarding agent makes it possible to secure consistency and reduce temperature difference between placement lifts, while also extending the time to reach peak temperature. This implies that the possibility of thermal crack induced by hydration heat is reduced. The best results are shown in the case of applying 4 placement lifts.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.362-371
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• 2012

Objective of this research was to secure the information on physical and chemical properties of peatmoss and coir dust. To achieve this, 6 kinds of peatmoss and 10 kinds of coir dust currently used in the country as the root medium components in plant factories were collected and analysed. The mean ${\pm}$ standard deviation (SD) of total porosity and container capacity in peatmoss and coir dust were $79.6{\pm}5.04$ and $83.6{\pm}6.18%$, and $69.9{\pm}10.17$ and $65.9{\pm}3.46%$, respectively. These indicate that peatmoss has higher water holding capacity than coir dust and the characteristics are highly varied among peatmoss. The 4 out of 5 kinds of peatmoss had lower than 10%, but coir dust had 12~26%, of air-filled porosity. The percentage of easily available water and buffering water in peatmoss and coir dust was 18~22 and 11~16% and 9~13 and 5.5~7.5%, respectively. These results indicate that precise irrigation is required when coir dust is used as the root medium. The ranges of pH and electrical conductivity (EC) were 3.46~4.17 and $0.137{\sim}0.253dS{\cdot}m^{-1}$ in peatmoss and 5.31~6.48 and $0.250{\sim}0.1.580dS{\cdot}m^{-1}$ in coir dust. However, $0.563{\pm}0.83dS{\cdot}m^{-1}$ in mean ${\pm}$SD of coir dust EC indicates that it is higher than that of peatmoss, and the coir dust are highly varied in EC. The cation exchange capacity of peatmoss was 3 to 4 times as high as that of coir dust. The coir dust had higher $NO_3$ and $PO_4$ and lower $NH_4$ than peatmoss. The K and Na concentrations in coir dust were extremely high indicating that these ions caused the rising in EC. The percentage of hot water and alkali extracts of peatmoss were 6.67~16.37 and 0~38%, whereas those of coir dust were 30.0~65.1 and 23.1~70.3%. These results mean that possible existence of growth inhibiting materials in coir dust.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.1
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• pp.123-134
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• 2014

Identification of methods to optimize the growth of a plant community, including the capacity of the soil to further sequester carbon, is important in urban design and planning. In this study, to construct and manage an urban park to mitigate carbon emissions, soil organic carbon of varying biomass, different park construction times, and a range of vegetation types were analyzed by measuring aboveground and belowground carbon in Seoseoul Lake Park and Yangjae Citizen's Forest. The urban parks were constructed during different periods; Seoseoul Lake Park was constructed in 2009, whereas Yangjae Citizen's Forest was constructed in 1986. To identify the differences in soil organic carbon in various plant communities and soil types, above and belowground carbon were measured based on biomass, as well as the physical and chemical features of the soil. Allometric equations were used to measure biomass. Soil total organic carbon (TOC) and chemical properties such as pH, cation exchange capacity (CEC), total nitrogen (TN), and soil microbes were analyzed. The analysis results show that the biomass of the Yangjae Citizen's Forest was higher than that of the Seoseoul Lake Park, indicating that older park has higher biomass. On the other hand, TOC was lower in the Yangjae Citizen's Forest than in the Seoseoul Lake Park; air pollution and acid rain probably changed the acidity of the soil in the Yangjae Citizen's Forest. Furthermore, TOC was higher in mono-layered plantation area compared to that in multi-layered plantation area. Improving the soil texture would, in the long term, result in better vegetation growth. To improve the soil texture of an urban park, park management, including pH control by using lime fertilization, soil compaction control, and leaving litter for soil nutrition is necessary.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.288-297
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• 2004

Puporse: The aims of this study were to evaluate the change of $[^18F]fluoromisonidazole$($[^18F]FMISO$) uptake in C3H mouse squamous cell carcinoma-VII (SCC-VII) treated with mild hyperthermia ($42^{circ}C$) and nicotinamide and to assess the biodistribution of the markers in normal tissues under similar conditions. Methods and Materials: $[^18F]FMISO$ was producedby our hospital. Female C3H mice with a C3H SCC-VII tumor grown on their extremities were used. Tumors were size matched. Non-anaesthetized, tumor-bearing mice underwent control or mild hyperthermia at $42^{circ}C$ for 60 min with nicotinamide (50 mg/kg i.p. injected) and were examined by gamma counter, autoradiography and animal PET scan 3 hours after tracer i.v. injected with breathing room air, The biodistribution of these agents were obtained at 3 h after $[^18F]FMISO$ injection. Blood, tumor, muscle, heart, lung, liver, kidney, brain, bone, spleen, and intestine were removed, counted for radioactivity and weighed. The tumor and liver were frozen and cut with a cryomicrotome into 10- um sections. The spatial distribution of radioactivity from the tissue sections was determined with digital autoradiography. Results: The mild hyperthermia with nicotinamide treatment had only slight effects on the biodistribution of either marker in normal tissues. We observed that the whole tumor radioactivity uptake ratios were higher in the control mice than in the mild hyperthermia with nicotinamide treated mice for $[^18F]FMISO$ ($1.56{\pm}1.03$ vs. $0.67{\pm}0.30$; p=0.063). In addition, autoradiography and animal PET scan demonstrated that the area and intensity of $[^18F]FMISO$ uptake was significantly decreased. Conclusion: Mild hyperthermla and nicotinamide significantly improved tumor hypoxia using $[^18F]FMISO$ and this uptake reflected tumor hypoxic status.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.179-190
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• 2012

This study was performed to obtain a heat saving effect and enhance the efficiency of a greenhouse by using a hot water piping in order to minimize the operating costs of a greenhouse as oil prices continue to rise. This method also reduces the likelihood of accidents caused by snowdrifts in regions with heavy snowfall. In general, the experimental plot was $2.0{\sim}6.0^{\circ}C$ higher than the control plot. When the skylight felt was opened, the minimum temperature was in the range of $3.0{\sim}12.0^{\circ}C$. Therefore, we judged that damage caused by snowdrifts may be prevented partly by active heating. The temperature difference inside of the greenhouse by height was insignificant. The maximum heating load of the greenhouse according to crop was respectively about $37,000kcal{\cdot}h^{-1}$ and $41,700kcal{\cdot}h^{-1}$. During the experiment, the heat value of each designed temperature in the range of the minimum ambient temperature $-11.9{\sim}4.0^{\circ}C$ was about 95,000~322,000 kcal and it was in the range of $6,050{\sim}20,900kcal{\cdot}h^{-1}$. If it is compared with the maximum heating load, it can be shown that about 15~56% of the heating energy can be supplied. The total heat value and the amount of power consumption were 2,629,025 kcal and 677.3 kWh respectively during the experiment. If it is heated with diesel, a fossil fuel, the consumption during the experiment was 291 L and the cost was 331,700won. Total cost of using electric power was about 24,400 won and it is shown that it is about 7.5% of the cost of diesel consumption. Also, if the total amount of power consumption is converted into energy, it is approximately 582,200 kcal and the energy was just about 22% of the total heat value.