• Korean Journal of Organic Agriculture
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• v.29 no.2
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• pp.241-256
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• 2021

The current study was to evaluate the antioxidant activity of Phyllostachys bambusoides (PHB) as a feed additives and investigate whether its antioxidant activity could be helpful for increasing rumen fermentation characteristics and methane reduction. The antioxidant activity results showed that total polyphenols and flavonoids contents were 43.54 ± 8.68 mg CE/g and 17.13 ± 0.45 mg QE/g, respectively, and the IC₅₀ values for 1,1-diphenyl-2-prcrylhydrazyl (DPPH) and 2,2'-azino-bis (3- ethylbenzthiazoline-6- sulphonic acid) (ABTS) radical scavenging activity were 163.13 ± 19.25 ㎍/mL and 97.07 ± 4.46 ㎍/mL, respectively. Two heads of cannulated Hanwoo (450 ± 30 kg), consuming timothy hay and a commercial concentrate (60:40, w/w) twice daily (at 09:00 and 17:30) at 2% of body weight, with free access to water and a mineral block, were used as rumen fluid donors. An in vitro incubation experiment was performed after 6, 12, 24, 48, and 72 hr with PHB added at concentration of 2, 4, and 6% of timothy hay basis. Total gas emission decreased as the amount of PHB addition increased at 6 and 24 hr of incubation. However, PHB addition did not affect total volatile fatty acid production, and methane and carbon dioxide emission also decreased as the amount of addition increased at 48 hr of incubation. Therefore, PHB was expected to be used as methane reducing additives in the ruminants.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.28 no.3
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• pp.95-120
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• 2023

Methane (CH₄) is a key greenhouse gas in the atmosphere with 85 times greater greenhouse potent relative to carbon dioxide (CO₂). The atmospheric concentration of CH₄ is rapidly increasing due to the intensive usage of CH₄ and the thawing of the cryosphere. Additionally, with the current warming of ocean water, the dissociation of gas hydrates, an ice-like compound and the largest reservoir of CH₄ on Earth, is expected to occur, resulting in the release of CH₄ from the seafloor into the overlying water and atmosphere. Moreover, bottom water hypoxia is another concern that potentially introduces greenhouse gases into the atmosphere. With ongoing global warming and eutrophication, the size and duration of bottom water hypoxia are rapidly increasing. These low-oxygen conditions would relocate the redox zone shallower in sediment or in the water column, causing the release of CH₄ into the atmosphere and thereby intensifying global warming. However, there exists a gap in the understanding of CH₄ dynamics including its generation in relation to bottom water hypoxia. Therefore, this review article aims to understand the relationship between CH₄ and bottom water hypoxia and to draw attention to CH₄ investigation in Korea.

• Journal of Life Science
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• v.33 no.7
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• pp.593-604
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• 2023

The ocean accounts for over 70% of the Earth's surface and is a space of largely unexplored unknowns and opportunities. Korea is a peninsula surrounded by the sea on three sides, emphasizing the importance of marine research. The ocean has an extremely complex environment with immense biological diversity. In terms of microbiology, the marine environment has varying factors like extreme temperature, pressure, solar radiation, salt concentration, and pH, providing ecologically unique habitats. Due to this variety, marine organisms have very different phylogenetic classifications compared with terrestrial organisms. Although various microorganisms inhabit the ocean, studies on the diversity, isolation, and cultivation of marine microorganisms and the secondary metabolites they produce are still insufficient. Research on bioactive substances from marine microorganisms, which were rarely studied until the 1990s, has accelerated in terms of natural products from marine Actinomycetes since the 2000s. Since then, industries for bioplastic and biofuel production, carbon dioxide capture, probiotics, and pharmaceutical discovery and development of antibacterial, anticancer, antioxidant, and anti-inflammatory drugs using bacteria, archaea, and algae have significantly grown. In this review, we introduce current research findings and the latest trends in life science and biotechnology using marine microorganisms. Through this article, we hope to create consumer awareness of the importance of basic and applied research in various natural product-related discovery fields other than conventional pharmaceutical drug discovery. The article aims to suggest pathways that may boost research on the optimization and application of future marine-derived materials.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.570-578
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• 2003

Background : Ambient particles during Asian dust events are usually sized less than $10{\mu}m$, known to be associated with the adverse effects on the general populations. But, there has been no considerable evidence linking these particles to the adverse effects on airways. The objectives of this study was to investigate the possible adverse effects of Asian dust events on respiratory function and symptoms in subjects with bronchial asthma. Patients and Methods : From march to June 2002, Asthmatic patients who were diagnosed with bronchial challenge test or bronchodilator response were enrolled. We divided them into three groups; mild, moderate, and severe, according to the severity. Subjects with other organ insufficiency such as heart, kidney, liver, and malignancy were excluded. All patients completed twice daily diaries and recorded peak flow rate, respiratory symptom, and daily activity. Daily and hourly mean pollutant levels of particulate matter < $10{\mu}m$ in diameter($PM_{10}$), nitrogen dioxide($NO_2$), sulphur dioxide($SO_2$), ozone($O_3$) and carbon monoxide(CO) were measured at the 10 different monitoring sites. Results : Dust events occured 14 times during the study period. Daily averages of 4 air pollutant were measured with an increased level of $PM_{10}$, decreased level of $NO_2$ and $SO_2$, and no change in CO during dust days compared to those during control days. An increase in $PM_{10}$ concentration was associated with an increase of subjects with PEF variability of >20% (p<0.05), night time symptom(p<0.05), and a decrease in mean PEF (p<0.05), which were calculated by the longitudinal data analysis. Otherwise, there was no association between $PM_{10}$ level and bronchodialtor inhaler, and daytime respiratory symptoms. Conclusion : This study shows evidence that ambient air pollution, especially $PM_{10}$, during Asian dust events, could be one of the many aggravating factors at least in patients with airway diseases. This data can be used as a primary source to set up a new policy on air environmental control and to evaluate the safety of air pollution index. We also expect that this research will help identify precise components of dust, which are more linked to the adverse effects.

• Journal of Service Research and Studies
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• v.13 no.1
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• pp.63-75
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• 2023

Due to the development of industry, interest in air pollutants has increased. Air pollutants have affected various fields such as environmental pollution and global warming. Among them, environmental diseases are one of the fields affected by air pollutants. Air pollutants can affect the human body's skin or respiratory tract due to their small molecular size. As a result, various studies on air pollutants and environmental diseases have been conducted. Asthma, part of an environmental disease, can be life-threatening if symptoms worsen and cause asthma attacks, and in the case of adult asthma, it is difficult to cure once it occurs. Factors that worsen asthma include particulate matter and air pollution. Asthma is an increasing prevalence worldwide. In this paper, we study how air pollutants correlate with the number of emergency room admissions in asthma patients and predict the number of future asthma emergency patients using highly correlated air pollutants. Air pollutants used concentrations of five pollutants: sulfur dioxide(SO₂), carbon monoxide(CO), ozone(O₃), nitrogen dioxide(NO₂), and fine dust(PM₁₀), and environmental diseases used data on the number of hospitalizations of asthma patients in the emergency room. Data on the number of emergency patients of air pollutants and asthma were used for a total of 5 years from January 1, 2013 to December 31, 2017. The model made predictions using two models, Informer and LTSF-Linear, and performance indicators of MAE, MAPE, and RMSE were used to measure the performance of the model. The results were compared by making predictions for both cases including and not including the number of emergency patients. This paper presents air pollutants that improve the model's performance in predicting the number of asthma emergency patients using Informer and LTSF-Linear models.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.202-209
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• 1996

The environment in composting greenhouse is very different with the traditional greenhouse by biothermal energy and $CO_2$ concentration. This experiment aimed to investigate the environmental effects on the growth and development of tomato grown at composting greenhouse. The room temperature is not different between two greenhouses because of heating and ventilation, but the soil temperature in composting greenhouse is about 7$^{\circ}C$ to 15$^{\circ}C$ higher than that of traditional greenhouse. The emission concentration of ammonia gas is the highest, 117.3ppm, at the 6th day starting the digest, and were gradually lowered from 7th day, 11 became 15.7ppm at the 16th day. The concentration of $CO_2$ in composting greenhouse were 250 to 2000ppm higher than that of traditional greenhouse for 4 months starting digest. The growth and development of tomato grown at composting greenhouse was better than that of traditional greenhouse. The yield in composting greenhouse was also better than that of traditional greenhouse. The sugar contents of tomato grown at composting greenhouse became about 1 $^{\circ}$Brix higher than that of traditional greenhouse.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.6973-6979
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• 2014

To mitigate global warming and climate change, many countries are investing massively on the development of CCS technology, which is assumed to be the key technology to reduce $CO_2$ emissions. CCS technology is comprised of the capture, transport, and storage processes. During the capture process, impurities other than $CO_2$ are inevitably flowed into the $CO_2$ stream. In the present study, corrosion characteristics of a phosphate coated tube for $CO_2$ transportation was investigated with a $CO_2$ stream composed of $CO_2$, $H_2O$, $SO_2$, and $NO_2$. The test specimen was a phosphate coated steel tube, which was filled with $CO_2$ stream with the impurities mentioned above. SEM-EDS analysis is conducted to investigate the corrosion behavior. The results showed that although the H2O concentration did not exceed the solubility limit, corrosion occurred in the specimen, which has an inflow of $SO_2$ or $NO_2$. This suggests that the $SO_2$, $NO_2$ and $H_2O$ concentration should be strictly controlled. These results suggest that the $SO_2$ and $NO_2$ concentration should be controlled below 175ppm and 65ppm, respectively.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.83-87
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• 2014

The objective of this study was to examine the changes in carbon dioxide ($CO_2$) concentration due to application of solid $CO_2$ generator (Tansansol) in plastic greenhouses during winter cultivation of Korean melon. The experimental treatments consisted of four levels, namely, 0 (control) 10, 20 and 30bags with solid $CO_2$ generator per $600m^2$ of plastic greenhouse. $CO_2$ concentration in plots with solid gas generators was higher by 3.0-3.2% compared to control. Fruit weight, sugar content and color parameter were also enhanced due to application of solid $CO_2$ generator. The fraction of fermentated and unmarketable fruits were decreased by 2.9-3.9% and 5.4-7.3%, respectively, in plots where solid $CO_2$ generators were applied. The marketable yield increased by 10.3, 14.8 and 16.2% in plots with 10, 20 and 30bags with $CO_2$ generators, respectively. As a result, $CO_2$ concentration within the greenhouses was increased by applying $CO_2$ generators and it is positively affected the rate of photosynthesis.

• Journal of Mushroom
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• v.17 no.4
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• pp.211-217
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• 2019

Currently, cultivation of mushrooms using the Information and Communication Technology (ICT)-based smart farming technique is increasing rapidly. The main environmental factors for growth of mushrooms are temperature, humidity, carbon dioxide (CO₂), and light. Among all the mentioned factors, currently, only temperature has been maintained under automatic control. However, humidity and ventilation are controlled using a timer, based on technical experience.Therefore, in this study, a Pleurotus eryngii first-generation smart farm model was set up that can automatically control temperature, humidity, and ventilation. After installing the environmental control system and the monitoring device, the environmental condition of the mushroom cultivation room and the growth of the fruiting bodies were studied. The data thus obtained was compared to that obtained using the conventional cultivation method.In farm A, the temperature during the primordia formation stage was about 17℃, and was maintained at approximately 16℃ during the fruiting stage. The humidity was initially maintained at 95%, and the farm was not humidified after the primordia formation stage. There was no sensor for CO₂ management, and the system was ventilated as required by observing the shape of the pileus and the stipe. It was observed that, the concentration of CO₂ was between 700 and 2,500 ppm during the growth period. The average weight of the mushrooms produced in farm A was 125 g, and the quality was between that of the premium and the first grade.In farm B. The CO₂ sensor was in use for measurement purposes only; the system was ventilated as required by observing the shape of the pileus and the stipe. During the growth period, the CO₂ concentration was observed to be between 640 and 4,500 ppm. The average weight of the mushrooms produced in farm B was 102 g.These results indicate that the quality of the king oyster mushroom is determined by the environmental conditions, especially by the concentration of CO₂. Thus, the data obtained in this study can be used as an optimal smart farm model, where, by improving the environmental control method of farm A, better quality mushrooms were obtained.

• Korean Chemical Engineering Research
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• v.49 no.4
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• pp.491-497
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• 2011

In this work, we proposed the three different reactor systems for evaluating of synthetic natural gas(SNG) processes using the synthesis gas consisting of CO and $H_2$ and reactor systems to be considered are series adiabatic reaction system, series adiabatic reaction system with the recirculation and cooling wall type reaction system. The maximum temperature of the first adiabatic reactor in series adiabatic reaction system raised to 800. From the these results, carbon dioxide in product gas as compared to other systems was increased more than that expected due to water gas shift reaction(WGSR) and the maximum $CH_4$ concentration in SNG was 90.1%. In series adiabatic reaction system with the recirculation as a way to decrease the temperature in catalyst bed, the maximum $CH_4$ concentration in SNG was 96.3%. In cooling wall type reaction system, the reaction heat is absorbed by boiling water in the shell and the reaction temperature is controlled by controlling the amount of flow rate and pressure of feed water. The maximum $CH_4$ concentration in SNG for cooling wall type reaction system was 97.9%. The main advantage of the cooling wall type reaction system over adiabatic systems is that potentially it can be achieve almost complete methanation in one reactor.