• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.6
• /
• pp.812-817
• /
• 2012

Nitrate can serve as a terminal electron acceptor in place of carbon dioxide and inhibit methane emission in the rumen and nitrate reducing bacteria might help enhance the reduction of nitrate/nitrite, which depends on the type of feed offered to animals. In this study the effects of three levels of sodium nitrate (0, 5, 10 mM) on fermentation of three diets varying in their wheat straw to concentrate ratio (700:300, low concentrate, LC; 500:500, medium concentrate, MC and 300:700, high concentrate, HC diet) were investigated in vitro using buffalo rumen liquor as inoculum. Nitrate reducing bacteria, isolated from the rumen of buffalo were tested as a probiotic to study if it could help in enhancing methane inhibition in vitro. Inclusion of sodium nitrate at 5 or 10 mM reduced (p<0.01) methane production (9.56, 7.93 vs. 21.76 ml/g DM; 12.20, 10.42 vs. 25.76 ml/g DM; 15.49, 12.33 vs. 26.86 ml/g DM) in LC, MC and HC diets, respectively. Inclusion of nitrate at both 5 and 10 mM also reduced (p<0.01) gas production in all the diets, but in vitro true digestibility (IVTD) of feed reduced (p<0.05) only in LC and MC diets. In the medium at 10 mM sodium nitrate level, there was 0.76 to 1.18 mM of residual nitrate and nitrite (p<0.01) also accumulated. In an attempt to eliminate residual nitrate and nitrite in the medium, the nitrate reducing bacteria were isolated from buffalo adapted to nitrate feeding and introduced individually (3 ml containing 1.2 to $2.3{\times}10^6$ cfu/ml) into in vitro incubations containing the MC diet with 10 mM sodium nitrate. Addition of live culture of NRBB 57 resulted in complete removal of nitrate and nitrite from the medium with a further reduction in methane and no effect on IVTD compared to the control treatments containing nitrate with autoclaved cultures or nitrate without any culture. The data revealed that nitrate reducing bacteria can be used as probiotic to prevent the accumulation of nitrite when sodium nitrate is used to reduce in vitro methane emissions.

• Tunnel and Underground Space
• /
• v.27 no.4
• /
• pp.217-229
• /
• 2017

This study focuses on the improvement of the working environment in domestic collieries where temperature is increasing due to heat of the earth that is caused by the long-term mining. In order to improve the working environment of the mine, a ventilation evaluation was carried out for Hwasoon Mining Industry. In order to increase the ventilation efficiency of the mine, numerical analysis of the effect on temperature was carried out by using climsim, a temperature prediction program. The analysis shows that A coal mine needs $6,152m^3/min$ for in-flow ventilation rate but the total input air flowrate is $4,710m^3/min$, $1,442m^3/min$ of in-flow ventilation rate shortage. The 93 m hypothetical ventilation shaft from -395 ML to -488 ML could result about $3^{\circ}C$ temperature drop in the coal mine of -488 ML far. As a result of predicting the $CO_2$ concentration at -523 ML development using artificial neural network, the emission of $CO_2$ increased as the amount of coal and coal bed thickness increased. The factors that have the greatest effect on the amount of $CO_2$ emissions were coal layer thickness and coal mining. And, as the air quantity increases, it has a great effect on the decrease of carbon dioxide concentration.

• Journal of the Korean Wood Science and Technology
• /
• v.39 no.3
• /
• pp.269-280
• /
• 2011

Today, global warming is one of main problems all over the world. The cause of the global warming is carbon dioxide outbreak by the rapidly increasing energy use. Therefore, it is necessary to save energy in each industrious field. It was investigated that the half of total energy consumption over the world was used for construction and building. Therefore, the saving of the building energy plays a significant role in decreasing total energy consumption. With the considerable increase in building energy consumption, a green building rating system and certification are required to reduce building energy consumption and $CO_2$ emissions. Of various elements reducing building energy, the thermal conductivity of materials affects the energy consumption as a basic element, which is directly related with reducing energy consumption. In particular, as the thermal conductivity of finishing materials is an important factor to decide heating energy efficiency of floor heating system, the investigation and development are necessary.

• Economic and Environmental Geology
• /
• v.50 no.1
• /
• pp.27-34
• /
• 2017

Mineral carbonation for the storage of carbon dioxide is a CCS option that provides an alternative for the more widely advocated method of geological storage in underground formation. Carbonation of magnesium- or calcium-based minerals, especially the carbonation of waste materials and industrial by-products is expanding, even though total amounts of the industrial waste are too small to substantially reduce the $CO_2$ emissions. The mineral carbonation was performed with steelmaking reduction slag as starting material. The steelmaking reduction slag dissolution experiments were conducted in the $H_2SO_4$ and $NH_4NO_3$ solution with concentration range of 0.3 to 1 M at $100^{\circ}C$ and $150^{\circ}C$. The hydrothermal treatment was performed to the starting material via a modified direct aqueous carbonation process at the same leaching temperature. The initial pH of the solution was adjusted to 12 and $CO_2$ partial pressure was 1MPa for the carbonation. The carbonation rate after extracting $Ca^^{2+}$ under $NH_4NO_3$ was higher than that under $H_2SO_4$ and the carbonation rates in 1M $NH_4NO_3$ solution at $150^{\circ}C$ was dramatically enhanced about 93%. In this condition well-faceted rhombohedral calcite, and rod or flower-shaped aragonite were appeared together in products. As the concentration of $H_2SO_4$ increased, the formation of gypsum was predominant and the carbonation rate decreased sharply. Therefore it is considered that the selection of the leaching solution which does not affect the starting material is important in the carbonation reaction.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.4
• /
• pp.464-473
• /
• 2016

The air temperatures of the coast and inland are rising due to an increase in carbon dioxide emissions and abnormal climate phenomena caused by global warming, El Nino, La Nina and so on. The sea levels of the Earth are rising by approximately 2.0 mm per year (global average value) due to the thermal expansion of sea water, melting of glaciers and other causes by global warming. On the other hand, when it comes to designing a hydraulic structure or coastal hydraulic structure, the standard of the design water level is decided by analyzing four largeness tide values and a harmonic constant with the observed tidal water level or simulating numerical model. Therefore, the design tidal water level needs to consider an increasing speed of the seawater level, which corresponds to the design frequency. In the present study, the observed tidal water levels targeting 46 tidal stations operated by the Korea Hydrographic and Oceanographic Administration (KHOA) from the beginning of observations to 2015 per hour were collected. The variation of the monthly and yearly and increasing ratio were performed and divided into 7 seas, such as east and west part of the Southern Sea, south part and middle of the East Sea, south part and middle of the Western Sea, and Jeju Sea. The current study could be used to determine the cause of local seawater rises and reflect the design tidal water level as basic data.

• Membrane Journal
• /
• v.27 no.6
• /
• pp.499-505
• /
• 2017

The increasing number of natural disasters resulting from anthropogenic greenhouse gas emissions has prompted the development of a gas separation membrane. Carbon dioxide ($CO_2$) is the main cause of global warming. Organic polymeric membranes with inherent flexibility are good candidates for use in gas separation membranes and poly(dimethyl siloxane)(PDMS) specifically is a promising material due to its inherently high $CO_2$ diffusivity. In addition, poly(vinyl pyrrolidine)(PVP) is a polymer with high $CO_2$ solubility that could be incorporated into a gas separation membrane. In this study, poly(dimethyl siloxane)-poly(vinyl pyrrolidine)(PDMS-PVP) comb copolymers with different compositions were synthesized under mild conditions via a simple one step free radical polymerization. The copolymerization of PDMS and PVP was characterized by FTIR. The morphology and thermal behavior of the produced polymers were characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Composite membranes composed of PDMS-PVP on a microporous polysulfone substrate layer were prepared and their $CO_2$ separation properties were subsequently studied. The $CO_2$ permeance and $CO_2/N_2$ selectivity through the PDMS-PVP composite membrane reached 140.6 GPU and 12.0, respectively.

• Environmental and Resource Economics Review
• /
• v.27 no.3
• /
• pp.399-420
• /
• 2018

This study has attempted environmental economic analysis on the cost structure of offshore fisheries based on fishery management data published by the Fisheries Research Institute to examine the effect of the environmental policy on the fisheries for the effective implementation of the Paris Convention. Under the assumption that both fisheries and carbon dioxide are simultaneously produced, the cost structure of offshore fisheries were analyzed. Cost function in a translog form was estimated and SUR (Seemingly Unrelated Regression) model was used for the analysis. Here, $CO_2$ emission of offshore fishery was calculated by using National Federation of Fisheries Cooperatives' data on supply of tax exemption oil (2003~2016). The cost function estimation showed that there is a weak disposition between catches and $CO_2$ emissions during the sample period, and the marginal abatement cost (MAC) is estimated at 1,457 won per year. In addition, for the same period, when 1% of $CO_2$ per horsepower is to be reduced MAC increases by 2.2%, and when 1% of $CO_2$ per 1 ton of catch is to be reduced, MAC increases by 1.4%.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.39 no.4
• /
• pp.223-233
• /
• 2021

Systematic and continuous monitoring and management of the energy consumption of buildings are important for estimating building energy efficiency, and ultimately aim to cope with climate change and establish effective policies for environment, and energy supply and demand policies. Globally, buildings consume 36% of total energy and account for 39% of carbon dioxide emissions. The purpose of this study is to generate three-dimensional thermo-spatial building models with photogrammetric technique using drone TIR (Thermal Infrared) images to measure the temperature emitted from a building, that is essential for the building energy rating system. The aerial triangulation was performed with both optical and TIR images taken from the sensor mounted on the drone, and the accuracy of the models was analyzed. In addition, the thermo-spatial models of temperature distribution of the buildings in three-dimension were visualized. Although shape of the objects 3D building modeling is relatively inaccurate as the spatial and radiometric resolution of the TIR images are lower than that of optical images, TIR imagery could be used effectively to measure the thermal energy of the buildings based on spatial information. This paper could be meaningful to present extension of photogrammetry to various application. The energy consumption could be quantitatively estimated using the temperature emitted from the individual buildings that eventually would be uses as essential information for building energy efficiency rating system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.1
• /
• pp.200-207
• /
• 2019

Cement is one of the most commonly used materials in the construction and civil engineering industry. However, emissions of carbon dioxide generated during the production of cement have been linked to climate change and environment pollutants. In order to replace cement, many studies have been actively performed research to utilizing Blast Furnace Slag(BFS), which is a byproduct of the steel industry. This study aims to investigate the physiochemical properties of the BFS powder based grout to determine whether it can be used as an environment-friendly grout material. As a fine powder, BSF can be used instead of cement grout due to its potential hydraulic property. BSF has also been known for its ability to strengthen materials long-term and to densify the internal structure of concrete. In order to investigate the physicochemical properties of the BFS powder based grout as a grout material, in this study assessment tests were performed through a gel-time measurement, uniaxial compressive strength, and chemical resistance tests, and heavy-metal leaching test. Characteristics and advantages of the slag were studied by comparing slag and cement in various methods.

• Membrane Journal
• /
• v.29 no.3
• /
• pp.173-182
• /
• 2019

Much research has been made for finding new and eco-friendly alternative sources of energy to solve the problems related with the pollution caused by emissions of greenhouse gases such as carbon dioxide as the use of fossil fuels increases worldwide. Among them, fuel cells draws particular interests as an eco-friendly energy generator because only water is obtained as a by-product. Anion exchange membrane-based alkaline fuel cell (AEMFC) that uses anion exchange membrane as an electrolyte is of increased interest recently because of its advantages in using low-cost metal catalyst unlike the PEMFC (potton exchange membrane fuel cell) due to the high-catalyst activity in alkaline conditions. The main properties required as an anion exchange membrane are high hydroxide conductivity and chemical stability at high pH. Recently we reported a chemically crosslinked poly(2-dimethyl-1,4-phenylene oxide) (PPO) by reacting PPO with N,N,N',N'-tetramethyl-1,6-hexanediamine as novel anion exchange membranes. In the current work, we further developed the same crosslinked polymer but having enhanced physicochemical properties, including higher conductivity, increased mechanical and dimensional stabilities by using the PPO with a higher molecular weight and also by increasing the crosslinking density. The obtained polymer membrane also showed a good cell performance.