• New & Renewable Energy
• /
• v.19 no.1
• /
• pp.22-30
• /
• 2023

Recently, the use of renewable energy has been increasing to achieve carbon neutrality. The concept of a zero-energy building is also attracting attention. In this study, a preliminary study was conducted to analyze the feasibility of a hybrid wind and solar power generation system between buildings that utilize the building wind generated by the Venturi effect. For this purpose, the wind speed and sunshine hours were monitored in the area where the building wind blows by the Venturi effect, and the power generation depending on system types, areas, and season was estimated. Consequently, the wind power generation system showed a larger amount of power per area than solar power. The wind power systems can generate larger power if wind power blades are installed along the height of the building. As a preliminary study, this study verified the feasibility of the system utilizing building wind and suggested follow-up studies.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2022.11a
• /
• pp.1038-1040
• /
• 2022

지속적인 지구 평균 기온 상승으로 인해 우리나라를 포함한 전 세계적으로 탄소중립을 위한 혁신이 이루어지고 있다. 본 연구는 해양수산부 '해양수산분야 2050 탄소중립 로드맵'의 기준에 따라 에너지 자립률을 극대화하고 효율을 최적화시킨 제로에너지 탄소중립 건축물을 제시한다. 태양광 발전 시스템에서, 패널의 태양 일주추적 기능을 통해 에너지 발전률을 극대화하고, 패널 하향정렬 및 딥러닝 모델을 통해 유지 보수를 용이하게 하여 성능 저하를 예방한다. 폐열을 이용한 열 회수/바이패스 환기 시스템을 통해 에너지 효율을 최적화하고, 온/습도에 가중치를 부여하여 모호했던 환기 시스템 결정 기준을 에너지 효율화에 맞게 최적화해 제시한다. 탄소중립 BEMS 기능이 내재된 앱 개발로 위의 건축물 시스템을 제어·관리한다. 본 연구를 통해 제로 에너지 건축물으로서 항만 건물의 가능성을 제고하고, 탄소중립 항만의 구현을 기대한다.

• Korean Journal of Agricultural Science
• /
• v.50 no.4
• /
• pp.927-940
• /
• 2023

Online shopping has been undergoing significant developments in the South Asian region in the last decade. Using a representative sample of Sri Lankan consumers, this study explored online food purchasing behavior in Sri Lanka, a developing nation and island in South Asia. Data were collected from 562 respondents from all nine provinces in Sri Lanka using an online survey. Consumer attitudes were evaluated using factor analysis, and factor scores were added as explanatory variables to the final model. An ordered logistic regression model was used to examine the impact of consumer demographics, economic variables, and consumer attitudes on online food purchases. Online food purchasing intensity was categorized into four groups that suited ordinal rankings: zero for never, low for rarely, medium for occasionally, and high for regularly. Results indicated that age, income, education, and living in urban areas affect the online food purchasing behavior of Sri Lankan consumers. In addition, trust, convenience, and attitudes toward price were powerful drivers of online food purchasing. The findings have a number of significant managerial ramifications for creating strategies to promote online food purchases in developing South Asian nations like Sri Lanka. Moreover, promoting online shopping could be a potential solution for traffic congestion, ultimately helping to mitigate the negative externalities associated with it, such as carbon emissions and air pollution.

• Transactions of the Korean hydrogen and new energy society
• /
• v.35 no.2
• /
• pp.175-184
• /
• 2024

This study focuses on investigating the importance of managing greenhouse gas emissions from global energy consumption, specifically examining domestic targets for clean hydrogen production. Using life cycle assessment, we evaluated reductions in global warming potential and assessed the carbon neutrality contribution of the domestic hydrogen sector. Transitioning from brown or grey hydrogen to blue or green hydrogen can significantly reduce emissions, potentially lowering CO₂ equivalent levels by 2030 and 2050. These research findings underscore the effectiveness of clean hydrogen as an energy management strategy and offer valuable insights for technology development.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.8
• /
• pp.1152-1158
• /
• 2016

Morphological and physiological alterations occur in the digestive system of weanling piglets, compromising the performance in subsequent phases. This experiment aimed at verifying the influence of glutamine, glutamate and nucleotides on the carbon turnover in the pancreas and liver of piglets weaned at 21 days of age. Four diets were evaluated: glutamine, glutamic acid or nucleotides-free diet (CD); containing 1% glutamine (GD); containing 1% glutamic acid (GAD) and containing 1% nucleotides (ND). One hundred and twenty-three piglets were utilized with three pigs slaughtered at day zero (weaning day) and three at each one of the experimental days (1, 2, 4, 5, 7, 9, 13, 20, 27, and 49 post-weaning), in order to collect organ samples, which were analyzed for the ${\delta}^{13}C$ isotopic composition and compared by means of time. No differences were found (p>0.05) among treatments for the turnover of the $^{13}C$ in the pancreas ($T_{50%}$ = 13.91, 14.37, 11.07, and 9.34 days; $T_{95%}$ = 46.22, 47.73, 36.79, and 31.04 days for CD, GD, GAD, and ND, respectively). In the liver, the ND presented accelerated values of carbon turnover ($T_{50%}=7.36$ and $T_{95%}=24.47days$) in relation to the values obtained for the GD ($T_{50%}=10.15$ and $T_{95%}=33.74days$). However, the values obtained for the CD ($T_{50%}=9.12$ and $T_{95%}=30.31days$) and GAD ($T_{50%}=7.83$ and $T_{95%}=26.03days$) had no differences (p>0.05) among other diets. The technique of $^{13}C$ isotopic dilution demonstrated trophic action of nucleotides in the liver.

• Analytical Science and Technology
• /
• v.10 no.1
• /
• pp.66-74
• /
• 1997

Influence of the axial dispersion on immobilized enzyme catalytic bed was investigated in order to examine the kinetic behavior of the biocatalysis. The enzyme employed in this study was the tyrosinase(EC 1.14.18.1) immobilized on carbon support : this system requires two substrates of phenol and oxygen. This enzyme has potential application for phenol degradation in waste water. A simulated reactor was a packed-bed reactor of 2.54cm in diameter and 10cm long, loaded with the immobilized carbon particle with an average diameter of $550{\mu}m$. A phenol feed in the strength of 55.5mM(5220ppm) was used to observe the behavior of the immobilized enzyme column at three different dissolved oxygen levels of 0.08445mM(2.7ppm), 0.1689mM(5.4ppm) and 0.3378mM(9.5ppm) with the flow rates in the range of 60(1mL/s) to 180mL/min(3mL/s). Examination of the Biot number and Damkolher numbers of the immobilized system enables us to eliminate the contribution of external mass transfer to set of differential equations derived from the dispersion model. Solution of the equation was finally obtained numerically with the application of the Danckwert boundary conditions and the assumed zero-and first order rates on the non-linear two substrate enzyme kinetics. Higher conversion of phenol was observed at the low flow rates and at the higher oxygen concentration. Comparison of axial dispersion and plug flow model showed that no detectable difference was observed in the column outlet conversion between the axial and the plug flow models which was in complete agreement with the previous studies.

• Journal of the Korean Institute of Gas
• /
• v.27 no.3
• /
• pp.41-51
• /
• 2023

As abnormal climatic event occur frequently due to global warming, many nations have proclaimed their commitment to achieving carbon neutrality and are actively pursuing a transition toward a hydrogen economy. At this time, ammonia has garnered significant attention not only as a high-capacity hydrogen carrier but also as a promising candidate as a carbon-free fuel. In particular, anion exchange membrane fuel cells offer the advantage of directly supplying ammonia to the fuel cell, eliminating the necessity for separate ammonia decomposition or hydrogen purification. Therefore, in this study, the operation principle and research trend of the anion exchange membrane fuel cell are reviewed, and several research using ammonia as a fuel in anion exchange membrane fuel cell are also investigated.

• Journal of the Korean earth science society
• /
• v.43 no.1
• /
• pp.41-59
• /
• 2022

In accordance with the enactment of 'the Paris Agreement' in 2015 and 'the Framework Act on Carbon Neutrality and Green Growth for Response to the Climate Crisis' in 2021, each local government has set appropriate reduction target of greenhouse gas to achieve the nationally determined contribution (NDC, the reduction target of 40% compared to 2018) of greenhouse gas (GHG) emissions in 2030. In this study, the current distribution of GHG emissions was analyzed in a time series centered on the Chungbuk region for the period from 1990 to 2018, with the aim of reducing GHG emissions in Chungbuk by 2030 based on the 2030 NDC and scenario. In addition, the prospected reduction by 2030 was estimated considering the projected emissions according to Busines As Usual in order to achieve the target reduction of GHG emissions. Our results showed that GHG emissions in Chungbuk and Korea have been increasing since 1990 owing to population and economic growth. GHG emissions in 2018 in Chungbuk were very low (3.9 %) relative to the national value. Moreover, emissions from fuel combustion, such as cement and lime production, manufacturing and construction industries, and transportation industries, were the main sources. Furthermore, the 2030 target of GHG emission reduction in Chungbuk was set at 40.2% relative to the 2018 value, in accordance with the 2030 NDC and 2050 carbon-zero national scenario. Therefore, when projected emissions were considered, the prospected reduction to achieve the target reduction of GHG emissions was estimated to be 46.8% relative to 2018. The above results highlight the importance of meeting the prospected reduction of GHG emissions through reduction means in each sector to achieve the national and local GHG reduction target. In addition, to achieve the 2030 NDC and 2050 carbon zero, the country and each local government, including Chungbuk, need to estimate projected emissions by year, determine reduction targets and prospect reductions every year, and prepare specific means to reduce GHG emissions.

• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.6
• /
• pp.413-419
• /
• 2011

Nanoscale zero-valent iron (NZVI) particles were tested as remediation media for groundwater contaminated by organic pollutants (e.g., TCE, trichloroethylene). The contaminated groundwater contained anions ($NO_3^-$, $Cl^-$, $SO_4^{2-}$, and $HCO_3^-$) and natural organic matter (NOM). Treatability of commercial NZVI particles (NANOFER 25, Nanoiron, Czech) was tested by using a synthetic groundwater and the field groundwater samples. More than 95% of 1.8 mM TCE was removed within 20 hours with a NZVI dosage of 25 g/L ($k=0.15hr^{-1}$). Repetitive degradation experiments revealed that the removal capacity of NANOFER 25 was 0.19 mmole TCE/g NZVI. TCE degradation reactions were not substantially affected by the presence of each anion with concentrations as high as 100 times the average field concentrations. However, when the four anions ($NO_3^-$, $Cl^-$, $SO_4^{2-}$, $HCO_3^-$) were present simultaneously. the degradation reactivity and removal capacity were decreased by 60% ($k=0.069hr^{-1}$) and 10%, respectively. The k value of TCE degradation in the presence of NZVI (25 g/L) with dissovled organic carbon of 2.5 mg/L was also decreased by 84% ($k=0.025hr^{-1}$). In the experiments with the field groundwater, more than 90% of $1.8{\mu}M$ TCE, which is the concentration of TCE at the source zone, was removed within 10 hours with a NANOFER 25 dosage of 25 g/L. The results imply that the contaminated groundwater can effectively be treated by NANOFER 25 with more information on the hydrogeology of the site.

• Journal of the Korean Geotechnical Society
• /
• v.30 no.2
• /
• pp.5-18
• /
• 2014

Depending on the underground load support mechanism, anchors are classified as friction anchors, bearing plate anchors and the recently developed combined friction-bearing plate anchors which combine the characteristics of both the friction and bearing plate type anchors. Even though numerous studies have been performed on bearing plate anchors, there were only few studies performed to observe the failure surface of bearing plate anchors. Furthermore most of the soil materials used on these tests were not real sand but carbon rods. In this study, sand was placed in the soil tank and laboratory tests were performed with bearing plate anchors installed with an embedment depth (H/h) ranging from 1~6. The variation in the pullout capacity and the behaviour of soil with the embedment depth (H/h) were observed. Ground deformation analysis program was also used to analyze soil displacement, zero extension direction, maximum shear strain contours. It was determined from the analysis of the results that at ultimate pullout resistance the deformation was 5 mm and the failure surface occurred in a narrower area when compared with results of the previous researches. It was also observed that the width of the fracture surface gradually becomes wider and expands up to the surface as the deformation increases from 10 mm to 15 mm.