• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.135-148
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• 2019

King oyster mushroom(Pleurotus eryngii) is one of the most commercially important mushrooms in Korea. Development of fruit body and disease occurrence are sensitive to environmental conditions such as temperature, humidity, carbon dioxide(CO₂) concentration. The purpose of this study was to investigate the changes in the growth environment of king oyster mushroom by installing Airocide, an air purifier for the purpose of improving mushroom cultivation environment. The results of the environment conditions, identification of pathogenic organisms and pathogenesis during the cultivation were as follows. Airocide operation increased the CO₂ concentration of the cultivation room by more than 400 ppm on average, but the increase of CO₂ concentration at this level had little effect on the quality and growth of fruit body. Operation of the Airocide tended to reduce the air humidity of the cultivation room and required more humidification. In humidifying conditions, the Airocide has the effect of lowering the species and density of bacteria and reducing bacterial symptoms and abnormal fruiting body of mushroom. Pseudomonas sp., the mushroom pathogen, was isolated from the cultivation room without Airocide, resulting in serious disease and loss of yields, so that only about 83% of substrate could harvest normal fruiting bodies. No disease symptom caused by bacteria and fungi in the cultivation room with Airocide. Trichoderma sp., Penicillium sp. and Cladosporium sp. were isolated from all experimental conditions, but did not inhibit fruit growth or caused diseased.

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.271-280
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• 2020

This study compared soil CO₂ efflux rates after fertilization, in Pinus densiflora and Quercus variabilis stands. Compound fertilizers were applied to the forest floor in March 2016, following a one-year calibration period (from March 2015 to February 2016). In situ soil CO₂ efflux rates were measured every month during the two-year study periods, using an infrared gas analyzer with a closed chamber system. Mean annual soil CO₂ efflux rates were higher following fertilizer application in the P. densiflora and Q. variabilis stands (P. densiflora: 2.180 μmol m^-2 s^-1; Q. variabilis: 1.977 μmol m^-2 s^-1) as compared with the rates measured during the calibration period (P. densiflora: 1.620 μmol m^-2 s^-1; Q. variabilis: 1.557 μmol m^-2 s^-1). The mean annual soil CO₂ efflux rates in the unfertilized treatments of both stands were not significantly different between the two-year study periods. The Q₁₀ values of fertilized treatments in Q. variabilis stands were higher in the fertilization period (3.41) than in the calibration period (3.14), whereas the Q₁₀ values in P. densiflora stands did not change between the fertilization and calibration periods. The Q₁₀ values of unfertilized treatments in the Q. variabilis stands were lower during the 2016-2017 period (3.69), than in the 2015-2016 period (3.85), whereas the Q₁₀ values in P. densiflora stands were higher during the 2016-2017 period (3.65), than in the 2015-2016 period (3.15). These results indicate that the increase in soil CO₂ efflux rates in P. densiflora stands could be more sensitive to fertilization compared with the rates in Q. variabilis stands.

• Journal of Forest and Environmental Science
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• v.39 no.1
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• pp.13-19
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• 2023

We investigated Soil respiration in Bluepine forest of western Bhutan, in relation to soil temperature, moisture content and soil pH and it was aimed at establishing variability in space and time. The Bluepine forest thrives in the typical shallow dry valleys in the inter-montane Bhutan Himalaya, which is formed by ascending wind from the valley bottom, which carries moisture from the river away to the mountain ridges. Stratified random sampling was applied and the study site was classified into top, mid, low slope and further randomized sample of n=20 from 30 m×30 m from each altitude. The overall soil respiration mean for the forest was found 2248.17 CO₂ g yr^-1 and it is ~613.58 C g yr^-1. The RS from three sites showed a marginal variation amongst sites, lower slope (2,309 m) was 4.64 μ mol m^-2 s^-1, mid slope (2,631 m) was 6.78 μ mol m^-2 s^-1 and top slope (3,027 m) was 6.33 μ mol m^-2 s^-1 and mean of 5.92 μ mol m^-2 s^-1, SE=0.25 for the forest. Temporal distribution and variations were observed more pronounced than in the space variation. Soil respiration was found highest during March and lowest in September. Soil temperature had almost inverse trend against soil respiration and dropped a low in February and peak in July. The moisture in the soil changed across months with precipitation and pH remained almost consistent across the period. The soil respiration and soil temperature had significant relationship R²=-0.61, p=0.027 and other variables were found insignificant. Similar relationship are reported for dry season in a tropical forest soil respiration. Soil temperature was found to have most pronounced effect on the soil respiration of the forest under study.

• Clean Technology
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• v.29 no.1
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• pp.46-52
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• 2023

Oxalic acid has been traditionally obtained via the oxidation of carbohydrates using nitric acid and catalysts. However, this process produces a variety of nitrogen oxides during oxidation and requires a separation process due to its various intermediates. These products and additional steps increase the harmfulness and complexity of the process. Recently, the electrochemical reduction of carbon dioxide into oxalic acid has been suggested as an environmentally friendly and efficient technology for the production of oxalic acid. In this electrochemical conversion system, zinc oxalate (ZnC₂O₄) is obtained by the reaction of Zn²⁺ ions produced by Zn oxidation and oxalate ions produced by CO₂ reduction. ZnC₂O₄ can then be converted to form oxalic acid, but this requires the use of a strong acid and heat. In this study, a system was proposed that can easily convert ZnC₂O₄ to oxalic acid without the use of a strong acid while also allowing for easy separation. In addition, this proposed system can also further convert the products into glycolic acid which is a high-value-added chemical. ZnC₂O₄ was effectively separated into Zn(OH)₂ powder and oxalate solution through a chemical treatment and a vacuum filtration process. Then the Zn(OH)₂ and oxalate were electrochemically converted to zinc and glycolic acid, respectively.

• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.424-429
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• 1990

A bio-sensor for the determination of glucose has been constructed by immobilizing the Citrobacter freundii or its organelle on carbon dioxide gas-sensor. The bacterial sensor was better than organelle in response, but the latter showed a shorter response time. The bacterial sensor gave linearity between 7.0 ${\times}\;10^{-4}$ and 1.0 ${\times}\;10^{-2}$ M glucose with a slope of 42.2 mV/decade in pH 7.0, 0.2 M tris-HCl buffer at 30$^{\circ}C$. The selectivity of this sensor was very high for glucose. Employing for the determination of glucose in serum, the sensor showed a good agreement with a routine analyzer.

• Journal of Chest Surgery
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• v.16 no.4
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• pp.539-546
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• 1983

Maximal expiratory flow-volume [MEFV] curves were studied in 22 patients who underwent pneumonectomy with various pulmonary lesions, such as lung cancer, bronchiectasis and tuberculosis etc, at the preoperative stage and 3 week, 4 month and 12 month after pneumonectomy for the analysis of the reduction and progressive improvement of postoperative ventilatory function. And the factors affecting them like as age difference and the site of pneumonectomy were also analyzed. From these curves peak flow rate [PF R], maximal expiratory flows at 25% and 50% of expired forced vital capacity [V25, V50] and forced vital capacity [FVC] were obtained. In addition, partial pressure of oxygen and carbon dioxide in arterial blood were measured. The results were as follows; 1. The mixed type, especially obstructive type of ventilatory impairment was observed at 3 week after operation. For 1 year of postpneumonectomy FVC was increased by 12.3% of predicted compared to 2.6% of predicted V50. 2. The improvement of FVC during 1 year of postpneumonectomy showed decreasing tendency with the increase of age but the changes of V25 and V50 were unremarkable. 3. The differences of immediate postoperative reduction and progressive improvement of ventilatory capacity after right and left pneumonectomy were analyzed. The reduction of V50, V25 and FVC at 3 week of postoperation were greater in patients with right pneumonectomy [20.9%, 18.2% and 26.2% of predicted] than in patients with left pneumonectomy 16.5%, 18.2% and 18.1%]. But there was no significant difference of these values at 12 month after pneumonectomy. 4. The partial pressure of oxygen in arterial blood [$PaO_2$] was decreased by 13.6 mmHg at 3 week after pneumonectomy compared to the preoperative stage but returned to the normal range within 4 month after pneumonectomy. However, TEX>$PaCO_2$ was within the normal range during 1 year of postoperation.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.37-43
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• 2001

Object : The rapid and early oxygen delivery to brain tissue was a common therapeutic method in the treatment of severe head injury patients. The purpose of this study was to investigate the effect of increased fraction of inspired oxygen in early stage of severe head injury. Methods : The parameters of research were CSF(cerebral spinal fluid) oxygen pressure($PcsfO_2$), lactate, pH, temperature, and CSF carbon dioxide pressure($PcsfCO_2$). We selected 28 patients with head trauma whose the Glasgow Coma Scale(GCS) score was less than 8 point at admission. All patients were mechanically ventilated and monitored with the commercial ICP monitoring device. Each of parameters was compared as increased fraction of inspired oxygen. In experimental cohort of 14 patients, the mean $PcsfO_2$ level was increased to $314.93{\pm}259.15mmHg$ by raising the $FiO_2$ from 40% to 100% for nine hours(p<0.05). And the mean CSF lactate level was decreased to $2.96{\pm}1.98mmol/L$ on 100% $FiO_2$ as compared with $5.98{\pm}3.25mmol/L$ on 40% $FiO_2$ in control group(p<0.05). The only above two parameters were showed statistically meaningful outcome. Conclusions : Although this study was performed in small cohort and short period, these results supports that increased inspired oxygen therapy in severe head injuried patients was recommended as a modality of treatment in future through the continuous survey.

• Fire Science and Engineering
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• v.33 no.4
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• pp.140-151
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• 2019

It is to assess the indoor air quality of the chemical hazardous materials exposed to the fire after firefighters returned to the fire scene. The research subject randomly selected four fire stations located in Seoul, Korea. Two fire stations were set up as control groups after the return of the firefighting activities at the actual fire scene, and two other fire stations were set up as control groups to measure the air quality of the room at normal levels regardless of the action. We conducted 24-hour monitoring for all fire accidents that occurred in Seoul Metropolitan using fire safety map computer system. Also, indoor air quality was measured immediately after homecoming if the experiment group was to be dispatched due to an accident of intermediate or larger scale. 11 hazardous substance items such as fine dust, formaldehyde, volatile organic compounds, PAH, VCM, acidity, asbestos, CO₂, NO₂, O₃ were measured according to the process test method. Three of 11 types of harmful substances exceeded domestic and foreign standards, and one of them was found to be close to foreign standards. In particular, total volatile organic compounds, carbon dioxide and sulfuric acids were 2.5 times, 2.2 times and 1.1 times higher than the standard. Also, for formaldehyde and sulfuric acid, it was measured higher in the control group than in the case group. This findings could be used in policies to improve indoor air quality in the fire station of the Seoul Metropolitan Government.

• Journal of Climate Change Research
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• v.4 no.3
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• pp.235-244
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• 2013

Carbon dioxide emission estimation methods consist of four tiers according to the IPCC guideline. In this study, estimated results by tier 3 and tier 4 were compared with the theoretically calculated $CO_2$ emissions based on the mass balance approach for a gas fired power plant between March and May 2011. It was found that the relative differences were upto 17% between the measured emissions by tier 4 and theoretically estimated emissions, while the results of tier 3 were similar to those from theoretically estimated ones. The comparisons suggested the possibility of misestimation due to replacing missing, abnormal, or invalid data in continuous emissions monitoring system. When using only the data without those missing, abnormal, or invalid data, the relative differences decreased somewhat but still showed consistent differences depending on the stack. It is suggested that this differences might be due to the accuracy of the measurement instruments for the tier 4, especially, for the flow rate measurement instrument.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.51-57
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• 2011

The calcium hydroxide($Ca(OH)_{2}$) which is flowed into the deteriorated tunnel by groundwater is reacted with carbon dioxide($CO_{2}$) and the vehicle's exhaust gas ($SO_{3}$). So its by-products are precipitated at the drainage pipe and these cause the drainage clogging. Most by-products are composed of $CaCO_{3}$ with calcite from a chemical experiment. The purpose of this study is mainly focused on comparison of attachment on each material of drainage pipe (teflon-coated steel pipe, silicon-Oil coated pipe, acrylic pipe and PVC pipe). The test was progressed to disembogue the CaO aqueous solution and tunnel outflow into each of the pipes. The experimental results show that the most produced scale pipe is PVC material and the followings are Acrylic pipe, Silicon-Oil coating pipe and Teflon coating pipe. But the long-term test results showed that teflon-coated steel pipe had a problem with durability because soil which was contained in the tunnel outflow occurred detachment of coating and corrosion of the steel pipe.