• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.6
• /
• pp.872-879
• /
• 2007

A study was conducted to investigate the seasonal changes in nutrient composition of pasture, voluntary intake and digestibility of sheep grazing an introduced Leymus chinensis pasture located in western Jilin Province, China. The whole-plant of L. chinensis and the samples simulating ingestion by sheep (simulating sample) were collected in spring (May, 2004), summer (July, 2004), autumn (September, 2004) and the end of winter (April, 2005). The contents of gross energy (GE), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and alkanes were determined. Voluntary intake and apparent digestibility of the nutrients in each season were also examined using 6 mature Chinese Northeast Merino ewes (differed among the seasons) grazing on a paddock of 1 ha size. The apparent digestibilities of GE, dry matter (DM), OM, CP, NDF and ADF of L. chinensis were significantly greater (p<0.05) in spring and summer than in autumn and winter. Metabolizable energy (ME) content was 12.13, 11.62, 8.66 and 10.40 MJ/kg DM for L. chinensis in spring, summer, autumn and winter respectively, and the corresponding voluntary feed intakes were 91, 119, 59 and 58 g/d per kg metabolic weight ($LW^{0.75}$). The ME contents and DM intakes in autumn and winter were significantly lower than in spring and summer (p<0.05). The intake of L. chinensis pasture was sufficient to provide ME requirements for maintenance by the dry ewes in all the seasons, but inadequate for maintenance protein requirement in winter. (Supported by funds from National Basic Research Program of China, Grant No. 2007CB106800).

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.3 no.3
• /
• pp.41-49
• /
• 2000

When sewage and industrial wastewater are treated to improve the coastal water quality, we usually consider the reduction of BOD and/or COD. Due to the inflow of untreated nitrogen and phosphorus, however, the coastal water has eutrophicated. Thus, to improve the water qualify, it is necessary to treat and reduce nitrogen and phosphorus which are the factors limiting algal growth. Hence, with regard to the adaption of Ocean Outfall for the treatment of wastewater in Suyoung Bay, we studied the effectiveness and environmental assessment of Ocean Outfall of which cost is lower than that of advanced treatment, The effectiveness of Ocean Outfall of the second treatment effluent in Nambu S.T.P. was simulated, using the eco-hydrodynamic model as far field model the result showed that the water quality of coastal area receiving wastewater on the surface sea has improved. But the concentrations of nitrogen and phosphorus around the diffuser of Ocean Outfall system can cause many problems on estuary, such as red tide, eutrophication and aquatic toxicity.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.3 no.3
• /
• pp.50-57
• /
• 2000

Budgets of fresh water, salt, DIN and DIP in the Nakdong river estuary were estimated in order to clarify the characteristics of material cycling and fluxes of nutrients with a simple box model. Freshwater inflow into this system was approximately 1.1E＋10m³/y, water exchange was 3.3E＋10m³/y and water residence time was 2.03 day assumed with salinity between estuary and adjacent ocean. Nutrients loadings were 3.2E＋09mol DIN/y3.7×10³, 2.7E＋07mo1 DIP/y, respectively. net ecosystem metabolism was 2.4E＋07mo1 C/y. Although the Nakdong river discharge was the main source of nutrients but Jang-rim sewage treatment plant effluent take parts of 16% of nitrogen and 10.2% of phosphorus loadings.

• Journal of Korean Society for Atmospheric Environment
• /
• v.27 no.1
• /
• pp.41-49
• /
• 2011

The power plants are one of the GHG major source among the sectors of fossil fuel combustion, therefore information of its emission factors is very essential to the establishing control strategies for the greenhouse gas emissions. The $CH_4$ and $N_2O$ concentration from power plants were measured using GC-FID and GC-ECD. The results showed that $CH_4$ emission factor was 0.33 kg/TJ and $N_2O$ emission factor was 0.88 kg/TJ. The $CH_4$ and $N_2O$ emission factors developed in this study were compared with those for IPCC default value and other countries emission factors. The results showed that $CH_4$ emission factor was lower than IPCC default value and Finnish emission factor, but higher than Japanese emission factor. $N_2O$ emission factor was higher Japanese emission factor and IPCC default emission factor however lower than Finnish emission factor. More research is needed on our own emission factors of various energy-consuming facilities in order to stand on a higher position in international negotiations regarding the treaties on climate changes.

• Journal of Advanced Navigation Technology
• /
• v.18 no.3
• /
• pp.254-260
• /
• 2014

We studied water level rising of drum versus time in the small hydraulic vertical water turbine system in this paper. The water level rises continuously up to a certain point with the passage of time if the constant incoming water is supplied, while it stops rising and maintains equilibrium state without any more rising because it increases position energy and evatually makes outgoing velocity and outgoing water quantities of runner area. The water level of drum is determined independent of size, height, width, figure of drum or runner configuration. It comes out that the water level is dependent only on the incoming and outgoing water quantities, and the output power has similar behavior. Therefore, desirable water level and output power are not available unless incoming water quantities is abundant. We validate this phenomina through applyng our methodolgies to the real small hydraulic vertical water turbine system under constructing and testing in industrial facilities in Korea.

• Journal of Nutrition and Health
• /
• v.37 no.2
• /
• pp.132-142
• /
• 2004

Nutritional factors affecting bone mineral density (BMD) in the different age groups of Korean men were investigated to obtain baseline data for maintaining bone health. Information on diet and anthropometry was collected in 80 elementary school children, 83 high school students, 87 adults aged 25 to 35 years and 98 elderly people over 60 years of age. Data for food and nutrient intake were obtained by 24-hour recall method. BMDs of lumbar spine (L$_2$- L$_4$) and femoral neck were measured by dual energy x-ray absorptiometry. The relationship between BMD and nutritional factors were analyzed. In the femoral neck, 5.7% of adults was classified as osteopenia and 47.9% and 37.8% of the elderly were classified as osteopenia and osteoporosis. It was shown that plant protein, Ca, p, Fe, thiamin, riboflavin and vitamin C intakes were related with BMD in all age groups. As for the mean adequacy ratio (MAR) of nutrients, the lowest quartile group of BMD showed significantly lower MAR among children. The RDA percent of nutrients was a strong influential factor on BMD. Subjects who consumed below 75% of Korean RDA in energy, vitamin A, thiamin, and vitamin C showed lower BMD. Stepwise multiple regression analysis revealed that MAR in children, vegetable Ca in adolescents, and vitamin C in adults and elderly people were the highest influential factor on BMD. Therefore, the above results demonstrated that not only calcium but also other nutrients such as protein, iron, vitamin A, riboflavin, and vitamin C were necessary in order to keep the healthy bone status. In addition, although there were various dietary factors that influenced bone density, MAR was identified as the major factor that affected bone density. Thus, a balanced diet that includes all nutrients is necessary for a healthy bone density. (Korean J Nutrition 37(2) : 132-142, 2004)

• KIEAE Journal
• /
• v.9 no.3
• /
• pp.61-68
• /
• 2009

Gwangju Metropolitan Government & Ministry of Environment have signed a model city in response to Climate Change agreement. The agreement calls for Gwangju to cut greenhouse gas emissions 10% below 2005 levels by 2015. Gwangju has seen this agreement as an opportunity to cut pollution and conserve the environment as well as to reinvigorate local economy. According to policy of Gwangju, Gwangju held design competition for Gwangju City Arboretum on march, 2009. The purpose of design competition was to give a wide publicity to Gwangju as Hub City of Asian Culture and construct carbon-neutral arboretum in accordance with the policy of 'Low-Carbon and Green Growth'. First of all, a design concept of arboretum is 'winding, round, overlay 'to reflect the landscape of Nam-do which is surrounded by mountains and river flows through the village. Second, the arboretum has five different places with these themes - Forest of Festivals, Health, Nature, Nostalgia, Education and Future. Each place has a symbolic theme park and different flow planning respectively. Third, the most critical point is that the arboretum is a carbon-neutral park. Gwangju arboretum will soon be developed in metropolitan sanitary landfill and constructed as the O2 arboretum based on low carbon strategy. Fourth, the O2 arboretum suggests specialized issue : 'Energy Saving', 'Recycling System', 'Green Network', 'Water System(rainwater maintenance and wetland development)'. Besides, main buildings(greenhouse, visitor center, Nam-do experience exhibition hall, and forest museum) is designed in consideration of harmony with topography character, surroundings. Also, planting will be a multilayer plant based on native landscape trees in consideration of function and the growth characteristics.

• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2005.10a
• /
• pp.47-58
• /
• 2005

Rice straw is one of the main renewable energy sources in Korea, and bio-oil is produced from rice straw with a lab. scale plant equipped mainly with a fluidized bed and a char removal system. We investigated how the reaction temperature affected the production of bio-oil and the efficiency of a char removal system. To elucidate how the temperature depended on the production of bio-oil, experiment were conducted between $450^{\circ}C\;and\;600^{\circ}C$ with a feed rate of about 300g/h. The mass balance was established in each experiment, and the produced gas and oil were analyzed with the aid of GCs and a GC-MS system. The char removal system is composed of a cyclone and a hot filter. In the experiments, we observed that the optimum reaction temperature range for the production of bio-oil is between $450^{\circ}C\;and\;500^{\circ}C$.

• Plant Journal
• /
• v.12 no.2
• /
• pp.24-30
• /
• 2016

The membrane separation processes have received attention due to advantages such as compactness, modularity, ease of installation, flexibility of operation, lower capital cost and lower energy consumption. In this study, we evaluated accuracy of cross-flow, co-current and counter-current models. With the most accurate model, we identified the operating conditions of the two-stage membrane separation and examined the effects of permeance and selectivity of the membrane by simulation. Futhermore, power requirements and operating cost savings due to the introduction of the heat exchanger were investigated by applying heat exchanger network synthesis technique in the two-stage membrane separation using vapor sweep.

• Journal of Hydrogen and New Energy
• /
• v.22 no.2
• /
• pp.152-160
• /
• 2011

The electromagnetic characteristics of FCEVs (fuel cell electric vehicles) are much different from the existing combustion engine cars as well as hybrid, plug-in-hybrid, and pure electric vehicles due to the high voltage/current generated by a fuel cell stack which uses a compressed hydrogen gas reacted with oxygen. To operate fuel cell stack efficiently, BOP (Balance of Plant) which is consisted of many motors in water pump, air blower, and hydrogen recycling pump as well as inverters for these motors is essential. Furthermore, there are also electric systems for entertainment, information, and vehicle control such as navigation, broadcasting, vehicle dynamic control systems, and so on. Since these systems are connected by high voltage or general cables, EMC (Electromagnetic compatibility) analysis for high voltage and general cable of FCEV is the most important element to prevent the possible electric functional safety errors. In this paper, electromagnetic fields by high voltage and general cables for FCEVs is studied. From numerical analysis results, total time harmonic electromagnetic field strength from high voltage and general cables have difference of 13~16 dB due to ground effect by impedance matching. The EMI results of FECV at 10 m distance shows difference of 41 dB at 30 MHz and 54 dB at 230 MHz compared with only general cable routing.