• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.318-322
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• 2006

The objective of this experiment was to investigate the effect of extrusion of ginseng roots in twin screw extruder on susceptibility of ginseng starch toward hydrolysis by ${\alpha}-amylase$ BAN 480L (Novozyme, Denmark) and cellulase Celluclast 150L and saccharification by amyloglucosidase AMG-E (Novozyme, Denmark). The extrusion was conducted at 22% and 30% moisture contents of feed at screw speed 300 rpm. Barrel temperature at zone 1 was adjusted at $100^{\circ}C$ and $120^{\circ}C$. The results showed that extrusion process improved the ginseng ${\alpha}-amylase$ susceptibility as compared to traditionally dried ginseng (white and red ginseng). Reducing sugar of hydrolyzed extruded samples was 2,500% of its initial concentration, whereas the reducing sugar of hydrolyzed non-extruded sample was only 200% of its initial concentration. However, addition of cellulase during liquefaction lowered the saccharification yield of both non-extruded and extruded samples as well.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.1-8
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• 1999

This study was carried out to estimate the warmed water irrigation and the warmed soil efficiency on protected cultivation of cucumber in winter season. The water of 28$^{\circ}C$ was continuously supplied for soil warming and that is $25^{\circ}C$ for warmed water irrigation. Cucumber growth was analyzed when tile soil kept up the optimum temperature in the root zone. The cucumber growth are compared with the warmed soil plots. isolated warmed soil plots and non-warmed soil plots. The cucumber growth in warmed soil plots and isolated warmed soil plots were 20~50% higher than non-warmed soil plots compare to that by the warmed irrigation. In the non-warmed soil plots, the stem diameter and the number of leaves in the warmed water irrigation plots are 10% higher than those in the normal water irrigation plots. The yields in isolated warmed soil plots were 37~38% higher than non-warmed soil plots and those in warmed soil plots were 85~96% higher than non-warmed soil plots. The fruit length, weight and diameter in warmed soil plots were 15% higher than those in the non-warmed plots.

• Journal of Welding and Joining
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• v.22 no.6
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• pp.57-63
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• 2004

Fracture toughness is an important parameter in designing offshore structures to ensure resistance to fracture at various temperatures. In this study, a series of experiments is carried out to obtain fracture toughness values (CTOD) of API 2W Gr.50B, welded using FCAW(Flux Cored Arc Weld). In particular, a comparison of absorbed impact energy and CTOD values are made with respect to two different welding groove shapes; double-V-groove and double-bevel-groove. Charpy impact tests are performed for specimens sampled near the root gap, and CTOD tests are carried out for three point bending specimens having the notch at weld zone. While Charpy impact test result is determined to be a good qualitative measure of fracture toughness, no quantitative correspondence between impact absorbed energy and CTOD values was found. Based on the experiment, it is observed that double-V-groove welds give lower transition temperature than those of double-bevel-groove.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.3
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• pp.164-169
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• 2004

A spatial interpolation scheme incorporating local geographic potential for cold air accumulation (TOPSIM) was used to test the feasibility of operational frost warning in Chatancheon basin in Yeoncheon County, where the introduction of new crops including temperate zone fruits is planned. Air temperature from April to June 2003 was measured at one-minute intervals at four locations within the basin. Cold-air accumulation potentials (CAP) at 4 sites were calculated for 3 different catchment scales: a rectangular area of 65 x 55 km which covers the whole county, the KOWACO (Korea Water Corporation) hydrologic unit which includes all 4 sites, and the sub-basins delineated by a stream network analysis of the digital elevation model. Daily minimum temperatures at 4 sites were calculated by interpolating the perfect prognosis (i.e., synoptic observations at KMA Dongducheon station) based on TOPSIM with 3 different CAPs. Mean error, mean absolute error, and root mean square error were calculated for 45 days with no precipitation to test the model performance. For the 3 flat locations, little difference was detected in model performance among 3 catchment areas, but the best performance was found with the CAPs calculated for sub-basins at one site (Oksan) on complex terrain. When TOPSIM loaded with sub-basin CAPs was applied to Oksan to predict frost events during the fruit flowering period in 2004, the goodness of fit was sufficient for making an operational frost warning system for mountainous areas.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.116-122
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• 2011

This study was carried out to investigate the effects of several cooling methods such as water hose cooling, mist, fog and control on growth and microclimate, and to develop a simple nutriculture bed for production of fresh leaves of narrowhead goldenaray 'Ligularia stenocephala'. When the root-zone was cooled with 240 L/hr flow rate of $13^{\circ}C$ ground water using water hose, the temperature was lowered approximately by 2 to $3^{\circ}C$ than that of control. The growth of narrowhead goldenaray were favorable in the water hose cooling compared with the other cooling methods. Nutrient culture system having part cooling effect around plant canopy was developed. The system was composed of 15 cm diameter of water hose on side wall of beds, cooling hose, and expanded rice hull media as organic substrate. When cool water which the temperature changed in the range of 14 to $22^{\circ}C$ diurnally with 240 L/hr of flow rate through water hose, the air temperature around canopy and root-zone temperature were dropped by $0.5^{\circ}C$ and $3^{\circ}C$ compared with that of conventional styrofoam bed, respectively. These results showed that newly devised bed system using water hose was simple and economical for the production of high quality narrowhead goldenaray leaves. This system might be practically used both at summer and winter season for the cultivation of narrow head goldenaray by part cooling or heating around root-zone and plant canopy.

• Journal of Biosystems Engineering
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• v.35 no.1
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• pp.46-52
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• 2010

The temperature of root zone was known as an important factor for the growth of crops and reduction of energy in greenhouse. The purpose of this study was to design the apposite inflow of calories per the unit area by comparison of temperature in the warmed and non-warmed soil. The energy needed for soil warming about pipe length showed the change of temperature on inflow and outflow as $2^{\circ}C{\sim}3^{\circ}C$(average $2.5^{\circ}C$). Therefore, the inflow per the unit hour was 3,450, 57,5 kcal/$h{\cdot}m^2$ on soil heating respectively. The non-warmed soil temperature in greenhouse made a difference by depth and it was partially affected inner temperature under 15 cm, but it was not above 15 cm. The soil temperature would be raised over $5^{\circ}C$ than non-warmed soil to increase effect of soil warming. Therefore, the inflow per the unit area that should be provided was about 100 kcal/$h{\cdot}m^2$.

• Journal of Bio-Environment Control
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• v.6 no.2
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• pp.110-116
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• 1997

This experiment was conducted to investigate the effects of root zone warming on fruit yield of oriental melon (Cucumis melo L. var. Makuwa) in winter season. Root zone was warmed by hot water flowing through pipe set at 35cm depth from the ridge. Treatments of minimum soil temperature at 20cm depth were 17, 21, $25^{\circ}C$ and non-warming from Jan. 18 to Apr. 18. The results are summarized as follows. 1. The blooming of female flower was faster 1 days in 17$^{\circ}C$ plot, 6 days in 21$^{\circ}C$ plot, and 7 days in $25^{\circ}C$ plot than in control plot and the days from blooming to harvesting were shorter 5 days in 17$^{\circ}C$ plot, 11 days in 21$^{\circ}C$ plot, and 12 days in $25^{\circ}C$ plot than in control plot. 2. Mean fruit weight was the highest in 21$^{\circ}C$ plot, followed $25^{\circ}C$, 17$^{\circ}C$ and control plots, respectively, and flesh thickness was the highest in $25^{\circ}C$ plot, followed by 21, 17$^{\circ}C$ and control plots, respectively. 3. Early and middle-phase yield was the highest in $25^{\circ}C$ plot, followed by 21$^{\circ}C$, 17$^{\circ}C$ and control plots but late yield was the highest in 17$^{\circ}C$ plot, followed by control, 21, and $25^{\circ}C$ plots. Total yield per 10a was higher 33% in 17$^{\circ}C$ plot, 49% in 21$^{\circ}C$ plot, and 37a in $25^{\circ}C$ plots than in control plot, harvested 1, 490kg per 10a. 4. Total yield was highest in 21$^{\circ}C$ plot, followed by $25^{\circ}C$, 17$^{\circ}C$, and control plots. Malformed and fermented fruit rates were the highest in control, followed by 17, 25, and 21$^{\circ}C$ plots and marketable fruit rate was 21, 25, 17$^{\circ}C$, and control plot in order.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.4
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• pp.315-320
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• 2020

Methylammonium lead iodide (MAPbI₃) thin films were grown at low temperatures on glass substrates via 3-zone chemical vapor deposition. Lead iodide (PbI₂) and lead bis (dipivaloylmethanate) [Pb(dpm)₂] precursors were used as lead sources. Due to the high sublimation temperature (~400℃) of the PbI₂ precursor, a low substrate temperature could not be constantly maintained. Therefore, MAPbI₃ thin films degraded into the PbI₂ phase. In contrast, for the Pb(dpm)₂ precursor, a substrate temperature of ~120℃ was maintained because the sublimation temperature of Pb(dpm)₂ is as low as 130℃ at a high vapor pressure. As a result, high-quality MAPbI₃ thin films were successfully grown on glass substrates using Pb(dpm)₂. The rms (root-mean-square) roughness of MAPbI₃ thin films formed from Pb(dpm)₂ was as low as ~19.2 nm, while it was ~22.7 nm for those formed using PbI₂. The grain size of the films formed from Pb(dpm)₂ was as large as approximately 350 nm.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.3
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• pp.185-191
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• 2005

An accurate prediction of dormancy release and bud burst in temperate zone fruit trees is indispensable for farmers to plan heating time under partially controlled environments as well as to reduce the risk of frost damage in open fields. A thermal time-based two-step phenological model that originated in Italy was applied to two important grapevine cultivars in Korea for predicting bud-burst dates. The model consists of two sequential periods: a rest period described by chilling requirement and a forcing period described by heating requirement. It requires daily maximum and minimum temperature as an input and calculates daily chill units (chill days in negative sign) until a pre-determined chilling requirement for rest release is met. After the projected rest release date, it adds daily heat units (anti-chill days in positive sign) to the chilling requirement. The date when the sum reaches zero isregarded as the bud-burst in the model. Controlled environment experiments using field sampled twigs of 'Campbell Early' and 'Kyoho' cultivars were carried out in the vineyard at the National Horticultural Research Institute (NHRI) in Suwon during 2004-2005 to derive the model parameters: threshold temperature for chilling and chilling requirement for breaking dormancy. The model adjusted with the selected parameters was applied to the 1994-2004 daily temperature data obtained from the automated weather station in the NHRI vineyard to estimate bud burst dates of two cultivars and the results were compared with the observed data. The model showed a consistently good performance in predicting the bud burst of 'Campbell Early' and 'Kyoho' cultivars with 2.6 and 2.5 days of root mean squared error, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.96-114
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• 1989

There are several meterorolgical stresses in the winter cereal crops. Among these stresses, cold injury is one of the most important stresses for wheat and barley production in Korea. The reduction in grain yield of the wheat and barley due to cold injury has occurred almost every year in Korea. The objective of the study was to get the basic information in relation to the cold injury and to detect the method minimizing the damage of cold injury. When the air temperature was the ranges of -13$^{\circ}C$ to -15$^{\circ}C$, the soil temperature at the crown part of the plant was very stable, whereas in the ranges of -2$^{\circ}C$ to -3$^{\circ}C$ the soil surface temperature was more unstable and cold than air and subterranean temperatures. The different parts of the plant in wheat and barley possess the different levels of cold hardiness. In comparison to the cold hardiness of plant parts, the leaf and crown are the less sensitive to cold injury than root and vascular transitional zone. The type and extent of stress is determined by the redistribution pattern of water during freezing. These types from freezing processes were three types: a) Equilibrium freezing pattern b) Non -equilibrium freezing pattern, c) Non-equilibrium freezing pattern typical of tender tissues. Cold hardiness in wheat plants were more harder than barley plants at vegitative stage, but inverted at the reproductive stage. Injuries by low temperature during the seasons of barley cultivation in Korea were occured mainly in four stage; in the first and third stage, frost injury occurs, the second stage, freezing injury, and the fourth stage, chilling injury.