• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.3
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• pp.157-163
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• 1995

The objective of this study is to obtain the basic data for investigating the effects of organic reserves on winter survial or regrowth yield. Dry matter, nitrogen and non-structural carbohydrate content of plants grown under $5^{\circ}C$ or $20^{\circ}C$ of culture temperature during 25 days were investigated. The dry matter content of leaves and roots were significantly reduced under $5^{\circ}C$ compared with $20^{\circ}C$culture condition. Comparing with the dry matter per plant under $20^{\circ}C$, those in leaves and roots under $5^{\circ}C$ decreased to 25% and 10%, respectively, after 25 days of temperature treatment. Total nitrogen content in leaves under $20^{\circ}C$ and $5^{\circ}C$ increased to 68% and 39% compared to the initial lenel(day O), respectively, during 25 days after temperature treatment, Nitrogen content in roots highly increased under 5 C while there was a little change under $20^{\circ}C$ condition. The nitrogen contents in roots under $5^{\circ}C$ and $20^{\circ}C$ were 39.0 and 30.8mgJg DM, respectively, after 25 days of temperature treatment. Total contents of soluble carbohydrate in both leaves and roots under $5^{\circ}C$ were higher than those under $20^{\circ}C$ condition. After 25 days of temperature treatment under$5^{\circ}C$ , their contents in leaves and roots were 1.4 and 2.0 times higher than those of under $20^{\circ}C$ condition. Stach atent in roots under $20^{\circ}C$ was less changed, while thatof under $5^{\circ}C$ greatly increased from 64.8 to 178.7mglg DM duling 25 days. 'Ihese results clearly showed that an accumulation of both nitrogen and non-structural carbohydrate in the plants occured under low temperature condition.e condition.

• International Journal of Oral Biology
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• v.40 no.4
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• pp.167-173
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• 2015

The purpose of this study was to investigate the antibacterial effect of the low temperature atmospheric plasma device with needle tip designed for easy approach to the oral cavity and root canal against Streptococcus mutans, Enterococcus faecalis and Candida albicans. The antibacterial activities evaluated by measuring clear zone of agar plate smeared with each bacteria after plasma treatment. To quantify antibacterial effects, dilution plate method was used. In addition, scanning electron microscope (SEM) was used for observation of changes in bacterial morphology. As treatment time of plasma increased, the clear zone was enlarged. The death rate was more than 99%. The SEM results showed that the globular shape of bacteria was distorted. These results suggest that needle tip plasma could be an innovative device for prevention of dental caries, and treatment of apical infection and soft tissue diseases.

• Textile Coloration and Finishing
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• v.9 no.5
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• pp.42-51
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• 1997

The purpose of this article is to investigate the effect of $O_{2}$ low temperature plasma treatment oft chitosan treatment of polyester fabrics. Moisture regain, static charge, crease resistance and reduction ratio of the treated fabric were measured. The results of this study were as follows: The add-on ratio and. the moisture regain of polyester fabrics treated with chitosan after treated by plasma(CP PET) were higher than those of polyester fabrics treated with only chitosan(C PET). The static charge of polyester fabrics decreased greatly with increasing the concentration of chitosan. A durability for laundering of CP PET was higher than those of C PET. The crease resistance of polyester fabrics decreased with ihcreasing the concentration of chitosan continuously. CP PET had higher decreasing rate and better durability than C PET. It showed that chitosan-treated polyester fabrics had over 90% reduction ratio after 10 times of laundering, and CP PET had better reduction ratio than C PET.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.4
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• pp.286-290
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• 2020

The formation of inorganic thin films in low-temperature solution processes is necessary for a wide range of commercial applications of organic electronic devices. Aluminum oxide thin films can be utilized as barrier films that prevent the deterioration of an electronic device due to moisture and oxygen in the air. In addition, they can be used as the gate insulating layers of a thin film transistor. In this study, aluminum oxide thin film were formed using two methods simultaneously, a thermal process and the DUV process, and the properties of the thin films were compared. The result of converting aluminum nitrate hydrate to aluminum oxide through a hybrid process using a thermal treatment and DUV was confirmed by XPS measurements. A film-based a-IGZO TFT was fabricated using the formed inorganic thin film as a gate insulating film to confirm its properties.

• Journal of the Korean Society of Food Culture
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• v.34 no.3
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• pp.361-368
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• 2019

The purpose of this study was to establish the best optimized extraction condition for the optimal development of fresh maca beverage using low temperature extraction and enzyme treatment. Low temperatures were applied to prevent heat-related nutritional loss during the extraction process. Best extraction conditions were investigated based on the ratio of maca to water, the ratio of enzymes, extraction temperature and time, and agitation. The optimal enzyme conditions were also examined after the treatment of cellulase:pectinase mixture to maintain the original color and flavor, as well as to increase the extraction yield. When cellulase:pectinase was 1:1, the extraction rate ranged from 77.84 to 79.29%. In addition, the best extraction rate was found when maca was mixed with twice volume of water and incubated at $45^{\circ}C$ ($84.05{\pm}0.32%$) with 90 rpm ($87.13{\pm}0.46%$) agitation for 3 hours ($84.73{\pm}0.29%$). Furthermore, sensory evaluation showed a high score in flavor, sweetness, and overall acceptability after adding 3% jujube concentrate into a fresh maca beverage.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.5
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• pp.507-511
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• 2024

Various process modifications have been used to minimize SiO₂ gate oxide aging in metal-oxide-semiconductor field-effect transistors (MOSFETs). In particular, post-metallization annealing (PMA) with a deuterium ambient can effectively eliminate both bulk traps and interface traps in the gate oxide. However, even with the use of PMA, it remains difficult to prevent high levels of radiation-induced gate oxide damage such as total ionizing dose (TID) during long-term missions. In this context, additional low-temperature heat treatment (LTHT) is proposed to recover from radiation-induced damage. Positive traps in the damaged gate oxide can be neutralized using LTHT, thereby prolonging device reliability in harsh radioactive environments.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.811-821
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• 2018

This study focused on the improvement of blueberry delivery service using pre-cooled ice and $SO_2$ pads to prevent an increase in the fruit temperature as well as decay. To maintain the fruit quality during low temperature storage, the effect of a $SO_2$ pad and modified atmosphere packaging was also examined. Harvested blueberries were precooled at $15^{\circ}C$, sorted, and packaged. And the fruits were placed in a similar environment as that for the parcel service. Part of the fruits were stored at $0^{\circ}C$ for long term storage. The air temperature in the delivery box increased along with an increase in the simulated delivery time regardless of the treatment. However, the rate of temperature increase was lower in the ice pad treatment. No significant difference was not found after 48 h. The oxygen concentration in the box ranged between 10.5 - 14.5% in the ice pad treatment, which was higher than that of the untreated control (7.5 - 11.9%) whereas the $CO_2$ concentration was lower in the ice pad treatment. No differences were found in the occurrence of off-flavor, decay, and sensory quality loss during the 48 hours of the parcel service simulation. The combined treatment of the $SO_2$ pad and modified atmosphere packaging (MAP) using a perforated film increased the shelf-life of the blueberry fruits, the overall quality such as firmness, and the soluble solid content was not different between the treatments except for the decay incidence. No decayed fruit was found in the combined treatment. However, the percentage of decayed fruit in the control was 25% on day 15 of storage and 75% on day 33 of storage, respectively.

• Korean Journal of Agricultural Science
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• v.51 no.1
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• pp.25-39
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• 2024

This study aimed to determine a method for restoring grasslands to forests in mountainous areas. The study was conducted in an area damaged by trampling due to construction activity and herding. Additionally, there were concerns of hindered tree growth due to the alpine region climate, characterized by the low temperatures, drying, and strong winds. Therefore, forest restoration treatments such as tillage, furrow, and shading were performed to improve growth conditions. From July 2021 to April 2023, soil temperature and moisture were monitored for each treatment plot, and changes in the initial growth and survival rate of Abies holophylla were investigated. Both soil temperature and soil moisture showed significantly higher values during the four seasons in the grassland-furrow treatment plot (p < 0.05). Compared to the grassland-control plot, the average soil temperature in winter was as high as 1.1℃, and the soil moisture in summer was as high as 20.3%. Additionally, the survival rate and relative growth rate were the largest in the grassland-furrow treatment plot. The survival rate was 87.5%, the relative growth rate in terms of height was 0.013, and the relative growth rate in terms of diameter at root collar was 0.023, indicating that furrow treatment had a positive effect on the initial survival and growth of seedlings. These results suggest that furrow treatment may be an appropriate restoration method when implementing forest restoration projects in areas where tree growth is challenged.

• Corrosion Science and Technology
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• v.12 no.6
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• pp.265-273
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• 2013

Ti-stabilized 11 wt% Cr ferritic stainless steels (FSSs) for automotive exhaust systems have been experienced intergranular corrosion (IC) in some heat-affected zone (HAZ). The effects of sensitizing heat-treatment and silicon on IC were studied. Time-Temperature-Sensitization (TTS) curves showed that sensitization to IC was observed at the steels heat-treated at the temperature lower than $650^{\circ}C$ and that silicon improved IC resistance. The sensitization was explained by chromium depletion theory, where chromium is depleted by precipitation of chromium carbide during sensitizing heat-treatment. It was confirmed with the results from the analysis of precipitates as well as the thermodynamical prediction of stable phases. In addition, the role of silicon on IC was explained with the stabilization of grain boundary. In other words, silicon promoted the formation of the grain boundaries with low energy where precipitation was suppressed and consequently, the formation of Cr-depleted zone was retarded. The effect of silicon on the formation of grain boundaries with low energy was proved by the analysis of coincidence site lattice (CSL) grain boundary, which is a typical grain boundary with low energy.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.5
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• pp.346-354
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• 2000

Effect of Nb addition on the phase transformation behavior was studied through continuous cooling transformation tests after reheating(reheating CCT) and deforming(deforming CCT) the 0.07%C-1.3%Mn-0.015%Ti-(0~0.08)% Nb steels. Transformation temperatures for deforming CCT were lower than those for reheating CCT, and the critical cooling rate for bainite transformation during deforming CCT was lower than that during reheating CCT. These enhanced hardenability for deforming CCT was considered to come from the sufficient solid solution of Nb in austenite during high temperature reheating before deformation. With Nb addition, the phase transformation temperature decreased, the bainite formation was enhanced, and the hardness of steel increased. Furthermore, these phenomena were more remarkable for deforming CCT than for reheating CCT. From the results, Nb-Ti bearing low carbon steel was considered to be a very favorable alloy system with good strength/toughness balance by recrystallization control rolling process.