• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.1-7
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• 2014

Dissolving part of xylan and lignin in lignocellulosic biomass by base can be used as pretreatment technique. Cork oak was pretreated with sodium hydroxide solution and the pretreatment effects were evaluated with two critical factors - NaOH concentration and pretreatment temperature. Some of xylan and lignin were removed by base pretreatment. At $90^{\circ}C$ and 13% NaOH pretreatment, 22.0% of lignin and 78.8% of xylan removed by base treatment. Enzymatic hydrolysis of cork oak which was pretreated at higher temperature or concentration was further improved. After pretreatment of cork oak with 13% NaOH at $90^{\circ}C$, the conversion rate of cellulose to fermentable sugars were reached up to 91.3%. At ethanol fermentation with enzymatic hydrolysate from different pretreatment conditions, all enzymatic saccharification liquids were well fermented by Saccharomyces cerevisiae.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.920-926
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• 2021

Capsules containing NaCl-MgCl₂ salt with 316L stainless steel or alloy N samples were irradiated in the Ohio State University Research Reactor for 21 nonconsecutive hours. A custom irradiation vessel was designed for this purpose, and details on its design and construction are given. Stainless steel samples that were irradiated during exposure had less corrosive attack than samples exposed to the same conditions without irradiation. Alloy N samples showed no significant effect of irradiation. This work shows a method for conducting in-reactor irradiation-corrosion experiments in static molten salts and presents preliminary data showing that neutron irradiation may decelerate corrosion of alloys in molten chloride salts.

• The Korean Journal of Mycology
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• v.51 no.2
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• pp.121-125
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• 2023

In this study, we examined the ectomycorrhiza (ECM) formed by a species of the genus Tuber, T. koreanum, with two indigenous Korean oak species, Quercus acutissima and Q. dentata. T. koreanum showed a high colonization rate for both oak species, with a higher mean colonization rate observed for Q. acutissima. The mycorrhizal characteristics of T. koreanum were described, revealing distinct morphological and anatomical differences between the ECM formed with the two host plants. This study is significant because it is the first to elucidate ECM formations of T. koreanum in indigenous oak trees. However, further studies are required to differentiate the ECM associations formed by T. koreanum from those of other Tuber species.

• Proceedings of the KSEEG Conference
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• 1999.04a
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• pp.4-4
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• 1999

• Proceedings of the KSEEG Conference
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• 1999.04a
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• pp.335-335
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• 1999

• Proceedings of the KSEEG Conference
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• 1999.04a
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• pp.336-336
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.79-79
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• 2002

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.345-353
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• 1994

Litter production and decomposition were investigated for 2 years in the oak, Quercus acutissima, and the pitch pine, Pinus rigida, stands in the vicinity of Kongju, Chungnam Province. Litter production was measured with litter trap at monthly basis. Litterbag method was used for the measurement of litter decomposition. Litter producion continued throughout the year, but showed a peak in autumn. Second peak in May or June was caused by falling of bud scales and reproductive organs. Average litter production in the oak and the pitch pine stands were $567.1g{\cdot}m^{-2}{\cdot}yr^{-1}\;and\;653.2g{\cdot}m^{-2}{\cdot}yr^{-1}$, respectively. Litter production in this study area were higher than those in other reports. Nutrient concentrations in litter were the highest in summer when the least litter production occurred, and the lowest in autumn when the greatest litter production occurred, except for calcium in the oak stand. Nutrient concentrations of the oak litter were higher than those in the pitch pine litter. After 1 year, % remaining mass of oak and pitch pine litter was 43.6% and 58%, respectively. After 21 months elapsed, % remaining mass of oak and pitch pine litter was 22.2% and 33.2%, respectively.

• Journal of Korean Society of Forest Science
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• v.106 no.3
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• pp.362-369
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• 2017

This study was carried out to provide basic data for active control of the anticipated damage through investigation and analysis of geographical and spatial occurrence distribution of oak wilt disease area. The damage of oak wilt disease was analyzed by investigating all the damage trees caused by oak wilt disease from 2011 to 2015 in three areas of Gwangtan-myeon, Paju-si, Gyeonggi -do. As a result, the closer to the ridge the more damage of the oak wilt was generated. Therefore, it is necessary to select the central management area from 0 to 40 m based on the ridge line for more effective control, and to intensively control the area. Also, it is difficult to predict the occurrence of damage by the slope because the damage situation represent differently by the region. By the diameter class, it was analyzed that the number of damaged trees was the largest in the average diameter class with the most number of the trees in each region.

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.147-154
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• 2001

In Korea and Japan, dried oak mushrooms are classified into 12 to 16 different categories based on its external visual quality. And grading used to be done manually by the human expert and is limited to the randomly sampled oak mushrooms. Visual features of dried oak mushrooms dominate its quality and are distributed over both sides of the gill and the cap. The 2nd prototype computer vision based automatic grading and sorting system for dried oak mushrooms was developed based on the 1st prototype. Sorting function was improved and overall system for grading was simplified to one stage grading instead of two stage grading by inspecting both front and back sides of mushrooms. Neuro-net based side(gill or cap) recognition algorithm of the fed mushroom was adopted. Grading was performed with both images of gill and cap using neural network. A real time simultaneous discharge algorithm, which is good for objects randomly fed individually and for multi-objects located along a series of discharge buckets, was developed and implemented to the controller and the performance was verified. Two hundreds samples chosen from 10 samples per 20 grade categories were used to verify the performance of each unit such as feeding, reversing, grading, and discharging unites. Test results showed that success rates of one-line feeding, reversing, grading, and discharging functions were 93%, 95%, 94%, and 99% respectively. The developed prototype revealed successful performance such as the approximate sorting capability of 3,600 mushrooms/hr per each line i.e. average 1sec/mushroom. Considering processing time of approximate 0.2 sec for grading, it was desired to reduce time to reverse a mushroom to acquire the reversed surface image.