• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.206-212
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• 2009

We investigated the patterns of freeze injury in dormant 'Changhowon Hwangdo' peach fruit by observing the extent of browning and germination of the branches that were treated with freezing temperature sets simulating the process of natural freezing incidences in orchards. Under the treatment of freezing temperature of $-15^{\circ}C$, the browning ratios were 15% for flower bud and less than 3% for both leaf bud and cambium. Under the $-20^{\circ}C$ treatment, the browning ratios were 40% for both flower and leaf buds and 1% for cambium. The browning ratios were 86%, 68% and 40% respectively for flower bud, leaf bud, and cambium under the $-25^{\circ}C$ treatment. All the samples showed 100% browning ratio under the $-30^{\circ}C$ treatment. The budburst ratios of leaf buds were 85%, 66%, 32%, and 0% under the -15, -20, -25 and $-30^{\circ}C$ treatments, respectively. The branches of peach fruit treated with the same freezing temperature showed different responses depending on the sampling date. In January the browning ratio was low and the budburst ratio was high whereas in February the opposite was the case, showing vulnerability of peach trees to low temperature after endo-dormancy release.

• Food Science and Preservation
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• v.3 no.2
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• pp.105-111
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• 1996

The conditions of cold stroage of Citrus unshiu Marc. var. okitsu produced in Cheju were investigated. The changes of peel moisture contents soluble solids, total sugar, vitamin C and density were slightly occured, and decay ratio was below 20% on keeping freshness relatively till late of March during cold storage. After thats decayed citrus fruits were increased gradually mainly from cold injury with lower temperature and high humidity. The loss of fruit weight, decrease of fruit hardness, and decrease of acid content were occured gradually during cold stroage. Because of the difficulty of long term storage for Citrus unshiu, the conditions and periods of cold storage would be determined after considering the physicochemical properties of fruits every year.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.121-131
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• 2008

This study was conducted to delineate temporal and spatial patterns of potential risk of cold injury by combining the short-term cold hardiness of Campbell Early grapevine and the IPCC projected climate winter season minimum temperature at a landscape scale. Gridded data sets of daily maximum and minimum temperature with a 270m cell spacing ("High Definition Digital Temperature Map", HD-DTM) were prepared for the current climatological normal year (1971-2000) based on observations at the 56 Korea Meteorological Administration (KMA) stations using a geospatial interpolation scheme for correcting land surface effects (e.g., land use, topography, and elevation). The same procedure was applied to the official temperature projection dataset covering South Korea (under the auspices of the IPCC-SRES A2 and A1B scenarios) for 2071-2100. The dormancy depth model was run with the gridded datasets to estimate the geographical pattern of any changes in the short-term cold hardiness of Campbell Early across South Korea for the current and future normal years (1971-2000 and 2071-2100). We combined this result with the projected mean annual minimum temperature for each period to obtain the potential risk of cold injury. Results showed that both the land areas with the normal cold-hardiness (-150 and below for dormancy depth) and those with the sub-threshold temperature for freezing damage ($-15^{\circ}C$ and below) will decrease in 2071-2100, reducing the freezing risk. Although more land area will encounter less risk in the future, the land area with higher risk (>70%) will expand from 14% at the current normal year to 23 (A1B) ${\sim}5%$ (A2) in the future. Our method can be applied to other deciduous fruit trees for delineating geographical shift of cold-hardiness zone under the projected climate change in the future, thereby providing valuable information for adaptation strategy in fruit industry.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.221-224
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• 2006

To analyze how the furrow directions made by the azimuth of $90^{\circ}-270^{\circ}(N\;90^{\circ})$, $120^{\circ}-300^{\circ}(N\;120^{\circ})\;and\;0^{\circ}-180^{\circ}(N\;180^{\circ})$ effect on the growth characteristics and yield of 2 and 3-year-old ginseng, both of $N\;90^{\circ}\;and\;N\;180^{\circ}$ compared with$N\;120^{\circ}$ recommended as the standard practices for ginseng cultivation. $N\;90^{\circ}$ showed lower quantum and air temperature during forenoon, while it showed higher quantum and air temperature from 15:00 to 19:00 than that of $N\;120^{\circ}$. $N\;180^{\circ}$ showed high quantum and air temperature due to the distinct increase of sunlight penetrated from 9:00 to 11:00, and which were similar to that of$N\;120^{\circ}$ during afternoon. Stem length and leaf area in $N\;90^{\circ}\;and\;N\;180^{\circ}$, respectively, were decreased more than that of$N\;120^{\circ}$, and those in $N\;180^{\circ}$ were decreased more distinctly than $N\;90^{\circ}$. Heat injury rate was decreased in $N\;90^{\circ}$, while it was increased distinctly in $N\;180^{\circ}$ that showed high quantum and air temperature, and which showed great variation according to the year. Yield of $N\;180^{\circ}$ was decreased more than that of$N\;120^{\circ}$ in 2004, the year when it was a relatively high air temperature during summer season, but which was increased more than that of$N\;120^{\circ}$ in 2005 showing a rotatively low air temperature.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.126-140
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• 1977

Present studies were carried out for breeding cold resistant clones of Citrus, improving overwintering techniques of Citrus in Jeju island as well as other southern region, Result obtained were as follows 1. In the vinyl house covered with two sheets of straw mat, 12 indivuals were found as non-injury and 15 were slightly injured by leaf freeging test at $-9^{\circ}C$ for 2 hours treatment. 2. In the condition of vinyl house covered with straw mat and viny film mulching and heat-in by sun-light, the inside temperature of vinyl house were not lowered below $-3^{\circ}C$ and the ground temperatura in vinyl house keeps above $0^{\circ}C$ during winter though outdoor temperature were lower by $-15^{\circ}C$(Daejeon area). 3. The vinyl tunnel inside the vinyl house and vinyl film mulching on ground position showed greater effectiveness for preventing heat loss from house but there were no significant difference between the color of vinyl film covered the tunnel. 4. In the vertical distribution of maximum temperature in vinyl house, the upper space was slightly higher than the lower position at high temperature condition, while minimum temperature was distributed as higher as the middle position, ground surface and upper position in order at low temperature condition 5. In the horizontal distribution of temperature in vinyl house, ground and surface-temperature of north side was lower than the other sides, and citrus planted within 30cm from north side wall died by cold injury and in the other side near wall appeared slight symptom of cold injury. 6. The insulating trench ($30{\times}30{\times}30cm$) packed with straw bundle installed under north wall might be effective to prevent heat loss of ground temperature. 7. In cloudy and snowy day, the temperature difference between indoor and outdoor were less, and the indoor temperature were maintained highly during night due to the effect of prevention of heat loss. 8. The highest temperature in a day was observed at about P.M. 3 both inside and outside of vinyl house and the lowest temperature was observed at about A.M. 6. The difference between the highest and lowest temperature of indoor in a sunny day was $19^{\circ}C$, compared with $9^{\circ}C$ on a cloudy or snowy day in late November. Especially, lowering of temperature in a snowy day was so less that the curve of temperature change was comparatively constant, 9. If the effective methods of citrus cultivation in vinyl house with improved clone such as hardiness. semi-dwarf and spur type are applied, it might be possible to cultivate the citrus tree safely in Jeju island as well as other southern rejion and to magnity the cultivation of citrus tree.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.55-60
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• 2015

Skin blackening is a serious postharvest disorder occurring in 'Fuyu' persimmon fruits (Diospyros kaki, 'Fuyu'). Phenolic content, polyphenol oxidase (PPO) and peroxidase (POD) activity, and lipid saturation were investigated in skin tissue of 'Fuyu' fruits. The phenolic compounds were accumulated unevenly on fruit skin depending on sunlight exposure, i.e., the most accumulation on sunny side and the least on the opposite, shaded side. The fruits harvested from shaded branches inside the canopy showed relatively even distribution of phenolic compounds in the skin. The activity distribution of PPO and POD were also uneven but only in fruits suffering f rom skin b lackening disorder, w ith the h ighest and the lowest a ctivity of PPO and P OD, respectively, in the blackened area of the fruit. When the sunny, southern sides of fruits were marked at harvesting time and fruits were stored at low temperature, a round black spot, as a symptom of skin blackening disorder, developed during storage exactly on the marked region. In addition, the sunny side of fruit showed higher lipid saturation, thus indicating adaptation to high temperature caused by the sunlight. These results suggest that the skin blackening disorder of 'Fuyu' fruits can be considered as a kind of chilling injury symptom that develops on the high-temperature-acclimated skin tissue of sunlight-exposed fruits when they are later exposed to low temperature.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.461-468
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• 2012

In this study, photosynthetic parameters such as the net photosynthesis rate, stomatal conductance, intercellular $CO_2$ concentration, and transpiration rate were examined in selected ginseng varieties and/or lines that are resistant (Yunpoong, HTIR 1, HTIR 2, and HTIR 3) and susceptible (Chunpoong) to high temperature injury (HTI). The net photosynthesis rate increased with the increase in the light intensity in all the HTI-resistant and -susceptible ginseng lines with a light saturation point of $200\;{\mu}mol\;m^{-2}s^{-1}$, except for Yunpoong that had a light saturation point of $400\;{\mu}mol\;m^{-2}s^{-1}$. At the light saturation point, the net photosynthesis rate in July was highest in HTIR 3, at $4.2\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$, and was lowest in Yunpoong, HTIR 1, Chunpoong, and HTIR 2, in that order, at 1.9 to $3.7\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$. The net photosynthesis rate in August was highest in Yunpoong at $5.9\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$, and lowest in HTIR 1 and HTIR 3 ($4.5\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$) and in other lines, in that order, at 2.8 to $2.9\;{\mu}mol\;CO_2\;m^{-2}s^{-1}$. The stomatal conductance in July was highest in HTIR 3 (0.055 mol $H_2O\;m^{-2}s^{-1}$) and Yunpoong, Chunpoong, HTIR 1, and HTIR 2 were 0.038, 0.037, 0.031, and 0.017 in that orders. In August, meanwhile, HTIR 1 showed the highest as 0.075, and followed by HTIR 3, Chungpoong, and HTIR 2 with 0.070, 0.047, and 0.023, respectively. The intercellular $CO_2$ concentration at the light saturation point in July and August was much lower in HTIR 2 at 139 and $185\;{\mu}mol\;mol^{-1}$ than in the other ginseng lines at 217 to 257 and 274 to $287\;{\mu}mol\;mol^{-1}$, respectively. The transpiration rate in July and August was higher in the HTI-resistant lines of Yunpoong, HTIR 1, and/or HTIR 3 at 0.83 to 1.03 and 1.67 to 2.10 mol $H_2O\;m^{-2}s^{-1}$ than in the other ginseng lines at 0.27 to 0.79 mol $H_2O\;m^{-2}s^{-1}$ and 0.51-1.65 mol $H_2O\;m^{-2}s^{-1}$, respectively. Conclusively, all the photosynthetic parameters that were examined in this study were generally higher in the HTI-resistant ginseng lines than in the HTI-susceptible lines, except for HTIR 2, and were much higher in August than in July, especially in the resistant ginseng lines. All these results can be used to provide basic information for the selection of HTI-resistant ginseng lines and the application of cultural practices that are efficient for ginseng growth, based on the photosynthetic characteristics of the lines.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.21 no.2
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• pp.73-78
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• 2015

Persimmons on the trees are often exposed to weather condition of cold temperature before harvest, which affects the fruit quality at harvest time and later storage. This study investigated the effect of the harvest season temperature on the storage quality of 'Fuyu' sweet persimmons. Monitoring the temperature changes in the orchard showed five times of cold temperature below the freezing temperature of persimmon, $-2.1^{\circ}C$, in the harvesting period between mid October and mid November with the lowest being as low as $-5.4^{\circ}C$. Among three different harvestings, the tertiary one at mid November showed decreased 'L' value and consistently high 'a' value of color index and high reduction in hardness during 150 days storage of fruits at $0^{\circ}C$ showing freeze-injured symptoms, compared to the first one at mid October and the second one at early November. The fruits of first harvest maintained consistently hard texture with increased 'a' color value probably due to postharvest ripening. The tertiary harvest exhibited increase in fructose and glucose contents and decrease in sucrose of the fruits, being very different from the first and secondary harvests which maintained constant level of all three free sugars. Mid November with possible sudden temperature drop is unsuitable period for harvesting sweet persimmons in the quality at harvest and later storage, and thus the harvest should be designed to be done before that time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.3
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• pp.198-205
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• 1982

In 1980, rice was considerably damaged by abnormal low temperature. In this paper, to determine the effect of low temperature on the growth and nutrition of rice, the experiment were carried out: varietal response to low temperature in the region with different elevations. Regional differences of heading response to low temperature were observed among varieties. The difference of days between regions were bigger in tongil lines than Japonica lines. Especially, Milyang 42 and Hangangchalbeo might belong the cold suceptible group, since the varieties were severely delayed their heading in the high mountainous region as comparred to plain region. The delay of heading with low temperature was brought out grain sterility, and fertility and ripening ratio is influenced cold tolerance and elevations, and it's decreased yield. Varieties with higher grain sterility by low temperature have higher total nitrogen content, but tended to have lower potassium and phosphate contents in the flag leaf. High content of total nitrogen, low contents of potassium and silicate were observed in the sterilized grain chaff an the opposite result were noted in the ferilized grain chaff at the ripening stage. The results reveal that the balance of these mineral element may play an important role in ripening and possibly cold tolerance.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.347-354
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• 2021

In the equipment industry such as chemical plants, high temperature, high pressure, and toxic fluids move between various facilities through piping. The movement and damage of pipes due to changes in the surrounding environment such as temperature changes, vibrations, earthquakes, and ground subsidence often lead to major accidents involving personal injury. In order to prevent such an accident, various types of expansion joints are used to absorb and supplement various shocks applied to the pipe to prevent accidents in advance. Therefore, it is very important to measure the deformation of the used expansion joint and predict its lifespan to prevent a major accident. In this paper, the deformation of the expansion joint was understood as a kind of motion, and the change was measured using a Hall Effect Sensor and a 9-Axis Sensor. In addition, we studied a system that can predict the deformation of expansion joints by collecting and analyzing the measured data using a general-purpose microcomputer (Arduino Board) and C language.