• Clean Technology
• /
• v.21 no.1
• /
• pp.22-32
• /
• 2015

In this study, we studied the characteristics of ion exchange for treatment of HSS (heat stable salts) which cause performance reduction in CO₂ gas capture amine solution using anion exchange resins. The optimum HSS removal efficiency, 96.1% was obtained when using strong base anion exchange resin SAR10 at dosage 0.05 g/mL, 316 K, pH 12 and the best resin regeneration efficiency, 78.8% was obtained using NaOH solution of 3 M at 316 K. The adsorption data were described well by the Freundlich model and the sorption intensity(n) was 2.0951 lying within the range of favorable adsorption. The adsorption selectivity coefficients were increased by increasing valences and size of ion and desorption selectivity coefficients showed a contradictory tendency to adsorption selectivity coefficients. By continuous HSS removal experiments, 13.3 BV of HSS contaminated solution was effectively treated and the optimum NaOH solution consumption was 5.2 BV to regenerate resins.

• The Journal of Sustainable Design and Educational Environment Research
• /
• v.15 no.1
• /
• pp.1-10
• /
• 2016

School facilities are one of the important educational requirements, and it is necessary to maintain safe and sustainable for the ongoing educational environment. For this reason, educational government department have an effort to produce school facilities that have become safe, comfort, convenient and high-quality. There are many methods to improve existing buildings and build new schools by energy efficient technology. Even though educational environment of school facilities are improved by the efforts, the energy consumption has a huge increase. Energy is a major budget item for schools. The accurate estimation of energy cost is critical for effective budgeting and financing for the school facility maintenance. Accurate energy cost estimation also allow for a anticipatable LCC (Life Cycle Cost) of new school facilities. In this study, in order to produce a basic information about the present energy usage status in domestic school facilities, energy usage quantity is regionally analysed according to physical characteristics of elementary, middle, and high school facilities. Those results will give a chance to see deeply the pros and cons of energy usage each regional school facilities.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.3
• /
• pp.259-267
• /
• 2010

In this study, the effect of particle size on the combustion characteristics of pulverized sub-bituminous coal was experimentally investigated. A laminar-flow-entrained reactor was designed and implemented to realize the desired heating ratio and temperature corresponding to the combustion atmosphere of a pulverized-coal-fueled furnace. The flame length and structure of burning particles according to different sizes were investigated. Coal combustion processes were clearly distinguished by direct visual observation of the flame structure. The onset point of volatile ignition is greatly affected by changes in the particle size, and the burning time of the volatiles is least affected by changes in the particle size. The length and instability of char flame also increase with the increase of the particle size. However, the char consumption rate within the residential time remains nearly constant.

• Korean Journal of Soil Science and Fertilizer
• /
• v.49 no.5
• /
• pp.531-540
• /
• 2016

The adoption of legume cover crops in no-tillage system can contribute to improve soil fertility by providing several benefits, including reduction in soil erosion, suppression of weed growth and N supply to subsequent crops. We conducted a field study to investigate the effect of cover crops and nitrogen fertilization rates on yield and nitrogen use efficiency of waxy corn (Zea mays L.) in no-tillage upland field. Two legume cover crops, hairy vetch (Vicia villosa Roth) and crimson clover (Trifolium incarnuturn L.) were mechanically terminated with roller in early June. For each cover crop treatment, nitrogen (N) fertilizer was applied at three different rates (145, 72.5 and $0kg\;N\;ha^{-1}$). The growth and yield characteristics of corn were significantly affected by the N fertilization rates in crimson clover plots, which suggest N mineralization from the cover crop residue was not sufficient. In contrast, N fertilization rates had no significant effect on growth and yield of corn in hairy vetch plots, indicating that the amount of N released from the cover crop is large enough to meet most of the N requirement of corn. However, the application of N fertilizer in hairy vetch cover plots resulted in slight increase of crop yield, though not statically significant, and high levels of N concentration in corn plant tissue possibly due to luxury consumption of N. Organic residues on the soil surface in hairy vetch cover plots had substantial amounts of N after harvest, ranging from 100 to $116kg\;N\;ha^{-1}$, which is presumably retained during winter season and released by microbial mineralization in subsequent year. The highest nitrogen yield efficiency was achieved in the plot with hairy vetch cover and no N fertilizer application, followed by the plot with hairy vetch cover and $72.5kg\;N\;ha^{-1}$ fertilization rate. In conclusion, hairy vetch showed better performance in corn productivity as compared with crimson clover. In addition, it was concluded that the application of N fertilizer between 0 and $72.5kg\;N\;ha^{-1}$ in combination with hairy vetch cover crop might be most efficient for corn yield under no-tillage system with climatic and soil characteristics similar to those of the experimental site.

• International Journal of Railway
• /
• v.2 no.3
• /
• pp.124-126
• /
• 2009

Energy savings can be achieved with optimum energy consumptions, brake energy regeneration, efficient energy storage (onboard, line side), and primarily with light weight vehicles. Over the last few years, the rolling stock industry has experienced a marked increase in eco-awareness and needs for lower life cycle energy consumption costs. For rolling stock vehicle designers and engineers, weight has always been a critical design parameter. It is often specified directly or indirectly as contractual requirements. These requirements are usually expressed in terms of specified axle load limits, braking deceleration levels and/or demands for optimum energy consumptions. The contractual requirements for lower weights are becoming increasingly more stringent. Light weight vehicles with optimized strength to weight ratios are achievable through proven design processes. The primary driving processes consist of: $\bullet$ material selection to best contribute to the intended functionality and performance $\bullet$ design and design optimization to secure the intended functionality and performance $\bullet$ weight control processes to deliver the intended functionality and performance Aluminium has become the material of choice for modern light weight bodyshells. Steel sub-structures and in particular high strength steels are also used where high strength - high elongation characteristics out way the use of aluminium. With the improved characteristics and responses of composites against tire and smoke, small and large composite materials made components are also found in greater quantities in today's railway vehicles. Full scale hybrid composite rolling stock vehicles are being developed and tested. While an "overdesigned" bodyshell may be deemed as acceptable from a structural point of view, it can, in reality, be a weight saving missed opportunity. The conventional pass/fail structural criteria and existing passenger payload definitions promote conservative designs but they do not necessarily imply optimum lightweight designs. The weight to strength design optimization should be a fundamental design driving factor rather than a feeble post design activity. It should be more than a belated attempt to mitigate against contractual weight penalties. The weight control process must be rigorous, responsible, with achievable goals and above all must be integral to the design process. It should not be a mere tabulation of weights for the sole-purpose of predicting the axle loads and wheel balances compliance. The present paper explores and discusses the topics quoted above with a view to strengthen the recommendations and needs for the weight optimization by design approach as a pro-active design activity for the rolling stock industry at large.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.14 no.2
• /
• pp.63-70
• /
• 2012

Larix kaempferi and Betula costata seedlings were grown under an elevated temperature ($27^{\circ}C$) for four weeks to understand initial changes on physiological characteristics caused by temperature rising in connection with global warming. At the end of the treatment, growth performance, leaf pigment content, antioxidative enzyme activities and malondialdehyde (MDA) content were measured and analyzed. Relative growth rates of the height of two tree species grown under elevated temperature ($27^{\circ}C$) were lower than those of control ($24^{\circ}C$) and dry weights of leaves, stems and roots were also reduced at higher temperature. Particularly, the root growth reduction of two tree species increased markedly at $27^{\circ}C$ over the study period, which increased the ratio of shoot to root. Under higher temperature, leaf pigment contents decreased, whereas anti-oxidative enzyme activities such as ascorbate peroxidase (APX) and catalase (CAT) increased as compared with the control. But MDA content was not affected by elevated temperature. In conclusion, the elevated temperature leads to root growth reduction, restriction of nutrient uptake from soil and the reduction of leaf pigment contents, which can inhibit the aboveground growth. In addition, higher temperature might act as a stress factor that causes growth reduction through the increase of energy consumption during a growth period.

• Resources Recycling
• /
• v.18 no.2
• /
• pp.16-29
• /
• 2009

This paper describes characteristics of pollutants in wastewater from the pulp and paper industry and biological technologies for the wastewater treatment. The wastewater from the pulp and paper industry contains high concentrations of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) and shows high toxicity and strong black-brown color. In particular, organic chlorinated compounds such as dioxins and furans may be formed by the chlorination of lignin in wood chips. Thus the pulp and paper industry is recently trending toward total chlorine-free (TCF) bleaching processes. All biological technologies for pulp and paper wastewater treatment are based on the contact between wastewater and bacteria, which feed on organic materials in the wastewater, thus they reduce BOD concentration in it. Both aerobic and anaerobic treatments were found to be effective for the wastewater treatment. Furthermore, advanced technologies such as fungal application and combined biological-filtration process have been also introduced to the wastewater treatment field. These technologies would be useful for water recycling to reduce water consumption throughout pulp and paper making process.

• Korean Journal of Poultry Science
• /
• v.20 no.3
• /
• pp.141-149
• /
• 1993

In order to develop a poultry manure dryer, a pilot dryer was designed and drying experiments were conducted to investigate the drying characteristics of poultry manure. According to the results, the pilot dryer could be operated without any air pollution problems. When poultry manure was dried from 79.2%(w.b. basis) moisture content, the final moisture content ranged from 38.7% to 57.9% depending upon the drying conditions. The drying results showed that drying rate was 189.8~198.0 kg/h and moisture evaporation rate was 124.0~125.4kg-$H_2$O/L. For this drying, electricity requirement was 9.5~19.3 Wh/kg and fuel consumption rate was 6.9~9.3 kg-$H_2$O/L with 50.2~65.1% thermal efficiency.

• Horticultural Science & Technology
• /
• v.28 no.3
• /
• pp.515-518
• /
• 2010

'Gangha' is new strawberry ($Fragaria{\times}ananassa$ Duch.) cultivar, which was released by National Institute of Highland Agriculture, RDA, in 2008. In 2004, this cultivar was originated from a cross between 'Samahberi' and 'Elan' and showed excellent ever-bearing characteristics including continuous flowering habit, high yield under long-day and high temperature condition. It was named 'Saebong No.2' after examining its characteristic and productivity in summer culture from 2006 to 2007. Again, after two regional adaptability tests in 2008, 'Gangha' was selected as an elite cultivar. The general characteristics of 'Gangha' include semi-spreading type, middle vigor, elliptic leaf, and long cluster in growth. The fruit shape is oval and fruit color is red. Fruit quality had 1ow activity, hardness but high soluble solids contents. This average fruit weight of 'Gangha' is about 12.0 g and the marketable yield is relatively high because of more flower cluster appearance. It is resistant against powdery mildew, anthracnose, and fusarium wilt. 'Gangha' is suitable for summer culture using domestic consumption because it is shows continuous flowering habit, high yield, and fruit quality under long-day and high temperature condition.

• Korean Journal of Community Nutrition
• /
• v.9 no.2
• /
• pp.161-172
• /
• 2004

The dietary habits of middle-aged obese, overweight and normal subjects were evaluated for the purpose of providing the background information of the degenerative disease control. A survey was conducted with 293 subjects (121 males and 172 females) between the ages 40-64 and they were divided into three groups of normal (BMI 18.5-22.9), overweight (BMI 23-24.9) and obese ($BMI\geq25$) based on the criteria of Korean Obesity Association (2000). The mean age of the subjects was $52.0\pm7.3(male)\;and\;51.9\pm6.9$ (female). Socioeconomic levels of subjects belong to the mid-upper class, since 71.9% of the males and 39.5% of the females received above a college education. More than 40% (44.6%) of males and 22.1% of females were obese, and educational background did not affect the obesity rate in males, whereas in females those who received lower education had a higher rate of obesity (p ＜ 0.001). The subjects had a similar degree of drinking to the national average value. but had a lower degree of smoking. The obese group had the higher rate of drinking (p ＜ 0.01) and smoking (p ＜ 0.01). The annual increase in weight, more than 4 kg, was 8.8% for normal group and 30.9% for obese group. However, there were no differences in the mean annual increase in weight among the three groups. In females there were greater tendencies of weight changes in obese group (p ＜ 0.05). About 44.9% of subjects responded that they were exercising regularly, and the obese group appeared to put into practice less than the other groups and to use more strenuous exercise. There was the greater rate of skipping dinner in the obese female group (p ＜ 0.05). The unbalanced dietary pattern was found more with normal group than the other groups (p ＜ 0.01). The food consumption frequency by food groups was not different among the groups. The obese group consumed less frequently meats, vegetables and fruits and had higher frequency in fish, legumes and their products, instant or fast food. In all subjects the higher rate of obesity was found with males than females and with those of heavier smoking and drinking, and in females the higher rate of obesity was found with lower education levels, skipping meals and having an unbalanced diet. In middle-aged subjects of this study with higher educational and socioeconomic background factors contributing to the effects of obesity may include smoking, drinking, educational background, skipping meals or unbalanced dietary pattern. The predictable characteristics for the development of obesity can be defined as sudden fluctuation of weights, exercise regularity and intakes of vegetables and fruits.