• Journal of Korean Society on Water Environment
• /
• v.35 no.3
• /
• pp.224-233
• /
• 2019

Nitrogen components in liquid manure can reduce safety and quality of environment harmfully. To minimize the environmental risks of manure, understanding fate of manure in environment is necessary. This study aimed at investigating applicability of a simplified Level III fugacity model for simulating $NH_3-N$ component to analyze environmental fate and transport of $NH_3-N$ in liquid manure and to provide basis for improving management of N in the liquid manure system and for minimizing the environmental impacts of N. The model simulation conducted for four environmental compartments (air, water, soil, and rice plants) during rice-cropping to trace $NH_3-N$ component and provided applicability of the Level III fugacity model in studying the environmental fate of $NH_3-N$ in manure. Most of $NH_3-N$ was found in water body and in rice plants depending upon the physicochemical properties and proper removal processes. For more precise model results, the model is needed to modify with the detailed removal processes in each compartment and to collect proper and accurate information for input parameters. Further study should be about simulations of various N-typed fertilizers to compare with the liquid manure based on a modified and relatively simplified Level III fugacity model.

• Journal of Korea Water Resources Association
• /
• v.55 no.11
• /
• pp.855-863
• /
• 2022

In this study, the Artificial Neural Network (ANN) was used to mapping air temperature in Seoul. MODerate resolution Imaging Spectroradiomter (MODIS) data was used as auxiliary data for mapping. For the ANN network topology optimizing, scatterplots and statistical analysis were conducted, and input-data was classified and combined that highly correlated data which surface temperature, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), time (satellite observation time, Day of year), location (latitude, hardness), and data quality (cloudness). When machine learning was conducted only with data with a high correlation with air temperature, the average values of correlation coefficient (r) and Root Mean Squared Error (RMSE) were 0.967 and 2.708℃. In addition, the performance improved as other data were added, and when all data were utilized the average values of r and RMSE were 0.9840 and 1.883℃, which showed the best performance. In the Seoul air temperature map by the ANN model, the air temperature was appropriately calculated for each pixels topographic characteristics, and it will be possible to analyze the air temperature distribution in city-level and national-level by expanding research areas and diversifying satellite data.

• Food Science and Preservation
• /
• v.17 no.4
• /
• pp.500-506
• /
• 2010

This study was conducted to compare and analyze the active and general components in mate leaf tea according to degree of fermentation conditions. The contents of tannic acid of hot water extracts from #1 (mate leaf), #2 (Mate leaf after fermentation and roasting), #3 (Mate leaf after Pan-firing), and #4 (Mate leaf after final drying) were decreased according to degree of fermentation conditions. Polyphenol contents of hot water extracts were approximate in #1 and #3, with measurements of 43.45 mg/g and 38.20 mg/g, respectively. Caffeine contents were 6.78 mg/g in #1, 4.30 mg/g in #3, and 3.65 mg/g in #4. In addition, the level of total free amino acid of #1 was higher than that of #2, #3, and #4. Lightness (L) and Redness (a) values increased and yellowness (b) values decreased after fermentation. When sensory tests were conducted, mate leaf tea after fermentation had pleasant taste.

• The Korean Journal of Food And Nutrition
• /
• v.31 no.5
• /
• pp.766-773
• /
• 2018

The purpose of this study is to make rice pie, a bakery item, to enhance use of rice flour and analyze quality characteristics of rice pie by adding roasted peanut flour and peanut sprout flour. Water content of rice pie adding roasted peanut flour or peanut sprout flour is lower than that of wheat pie. The pH of rice pie is lower than that of wheat pie, and pH becomes higher when roasted peanut flour or peanut sprout flour is added. Density of dough is lower in rice pie than in wheat pie, and when roasted peanut flour or peanut sprout flour is added, rice pie reveals higher density. Loss rate is higher in rice pie than in wheat pie, and when roasted peanut flour or peanut sprout flour is added, rice pie reveals lower loss rate. When roasted peanut flour or peanut sprout flour is added to rice pie, its brightness (L) and yellowness (b) decrease, while redness (a) increases. Hardness is higher in pie made of rice powder than in wheat pie, and when roasted peanut flour or peanut sprout flour is added, hardness becomes lower. Regarding composition of fatty acids in rice pie, saturated fatty acids observed are myristic acids, palmitic acids, and stearic acids. Monounsaturated fatty acids found are mainly oleic acids. Polyunsaturated fatty acids detected are linoleic acids, and are found more in pie made of rice powder, than in wheat pie.

• Korean Journal of Environmental Biology
• /
• v.38 no.1
• /
• pp.114-126
• /
• 2020

Bloom-forming toxic cyanobacteria Microcystis spp. are common in the summer season in temperate freshwater ecosystems. Often, it leads to the degradation of water quality and affects the quality of drinking water. In a previous study, NQ (naphthoquinone) compounds were shown to be effective, selective, and ecologically safe algicides for Microcystis spp. blooms. To analyze the superiority of developed NQ derivatives, we conducted a microcosm experiment using clay, which is frequently used in South Korea. Similar to previous studies, the NQ 40 and NQ 2-0 compounds showed high algicidal activities of 99.9% and 99.6%, respectively, on Microcystis spp. at low concentrations (≥1 μM) and enhanced phytoplankton species diversity. However, when treated with clay, a temporary algicidal effect was seen at the beginning of the experiment that gradually increased at the end. In addition, treatment with the NQ compounds did not affect either the abiotic or biological factors, and similar trends were observed with the control. These results showed that the NQ 2-0 compound was more effective, with no ecosystem disturbance, and more economical than the currently used clay. These results suggest that NQ 2-0 compound could be a selective, economically and ecologically safe algicide to mitigate harmful cyanobacterial blooms in the field.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.22 no.7
• /
• pp.492-507
• /
• 2010

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2009. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery and piping, and new and renewable energy. Various topics were covered in the field of general thermal and fluid flow such as an expander, a capillary tube, the flow of micro-channel water blocks, the friction and anti-wear characteristics of nano oils with mixtures of refrigerant oils, etc. Research issues mainly focused on the design of micro-pumps and fans, the heat resistance reliability of axial smoke exhaust fans, and hood systems in the field of fluid machinery and piping. Studies on ground water sources were executed concerning two well type geothermal heat pumps and multi-heat pumps in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included the heat transfer in thermoelectric cooling systems, refrigerants, evaporators, dryers, desiccant rotors. In the area of industrial heat exchangers, researches on high temperature ceramic heat exchangers, plate heat exchangers, frosting on fins of heat exchangers were performed. (3) In the field of refrigeration, papers were presented on alternative refrigerants, system improvements, and the utilization of various energy sources. Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and $CO_2$ were studied. Efforts to improve the performance of refrigeration systems were made applying various ideas of suction line heat exchangers, subcooling bypass lines and gas injection systems. Studies on heat pump systems using unutilized energy sources such as river water, underground water, and waste heat were also reported. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. In the area of cogeneration systems, papers on energy and economic analysis, LCC analysis and cost estimating were reported. Studies on ventilation and heat recovery systems introduced the effect on fire and smoke control, and energy reduction. Papers on district cooling and heating systems dealt with design capacity evaluation, application plan and field application. Also, the maintenance and management of building service equipments were presented for HVAC systems. (5) In the field of architectural environment, various studies were carried to improve indoor air quality and to analyze the heat load characteristics of buildings by energy simulation. These studies helped to understand the physics related to building load characteristics and to improve the quality of architectural environment where human beings reside in.

• Journal of the Korean association of regional geographers
• /
• v.4 no.2
• /
• pp.165-182
• /
• 1998

When tour site is being used by people for the destination of tour, it has a life, or it will lose its life as a tour site. Therefore this paper aims to, based on Butler's theory, has chosen 46 hot spring spots in Korea which are legally assigned and presently running, and tried to analyze the life cycles, the stage of dispositional characteristics, and visitors' favoritism, and to try to find activating method which is not decline. Out of 46 spots, 29 Places were found on the stage of development, which took high percentage, 4 were on the growing stage, 5 were on the mature stage, 5 were on the stagnation or decline stage and the rest 3 were on the stage of rejuvenation. Geographically, Korean hot springs were located on the plain or mountainous areas mostly, and less of them were on hills and coast lines. In water quality, most of places had simple water while the places with salt and sulfur contained water were marked low rate. The temperatures of hot spring water were variable between $25^{\circ}C{\sim}78^{\circ}C$, but the older hot springs were hotter than new ones. After observing the relationship between disposition characteristics and life cycles, the geographical locations and the matter of approach were found as majour influential factors to the life cycles of them. The type of mountainous areas were observed slow progress in life cycle, due to traffic problem, until the road expansion or pavement work were done. Meanwhile, the suburban ones adjacent to big cities were favored by hot spring tourists due to their easy approach and easy traffic. The new born hot springs with such conditions have shown the fast growth. As studied above, since the hot springs were supposed to be for recuperation and vacational, a hot spring with better recreational and accommodational facilities was more favored by tourists than the one with pretty interior decorations. It was because the tour purpose of people has been switched from single purpose to multi one. Thus, the suggestion for activating a declining hot spring and bringing people in them is to develop new and attractive tour resources, expanding the related area, maintaining good quality of water, developing a complex site for long-term tour, developed traffic routs, hot spring festivals, utilizing adjacent tour resources, preparing public water supply system, and assigning as special tour zone.

• Journal of Korea Technology Innovation Society
• /
• v.12 no.3
• /
• pp.471-498
• /
• 2009

The ability to judge a country's scientific standing is vital for the governments and businesses that must decide scientific priorities and funding. In this paper, we analyze the output and outcomes from research investment over the recent years, to measure the quality of scientific research on national scales and to set it in an international context. There are many ways to evaluate the quality of scientific research, but few have proved satisfactory. To measure the quantity and quality of science in different nations, we analyzed the numbers of published research papers and their citations. The number of citations per paper is a useful measure of the impact of a nation's research output. Essential at a were acquired from SCI database by Thomson Scientific, which indexes more than 8,000 journals, representing most significant materials in science and engineering. The purpose of this paper is to evaluate and compare the output and outcomes among nations in a variety of viewpoints and criteria. One of the implications in response to the result of analysis is that sustainable economic development in highly competitive world markets requires a direct engagement in the generation of knowledge. Even modest improvement in healthcare, clean water, sanitation, food, and transport need capabilities in engineering, technology, and medicine beyond many countries' reach. Nations exporting natural resources such as gold and oil can import technology and expertise, but only until these resources are exhausted. For them, sustainability should imply investment in alternative agricultural and technological capabilities through improvements in their skills base. A strong science base does not necessarily leat to wealth generation. However, strength in science has additional benefits for individual nations, and for the world as a whole.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.3
• /
• pp.431-438
• /
• 2014

Eogeul-tang is a traditional Korean soup dish made from dried pollack, minced beef, and tofu. This comparative study analyzed the quality characteristics of Eogeul-tang by varying the added amounts of cow gristle. The objective of this study was to analyze Eogeul-tang to promote its functionality and increased consumer preference. Collagen contents were $18.08{\pm}0.13g$ and $22.17{\pm}0.14g$ per 100 g of dried pollack skin and knee cartilage of cow, respectively. The overall collagen content was higher in the knee cartilage of cow. Different amounts of cow gristle (25%, 50%, 75%, and 100%) were added to traditionally cooked Eogeul-tang, and the general composition of Eogeul-tang was analyzed. Significant differences were exhibited in the amounts of water content, crude protein, crude fat, and crude ash depending on the added amounts of cow gristle. Moreover, the collagen content also significantly increased as the amount of gristle content increased. In particular, significant increases in the amounts of collagen components, including proline, glycine, and alanine were observed with increasing amount of gristle. When a sensory test was conducted on Japanese, overall preference values were highest for Eogeul-tang composed of 25% beef and 75% gristle compared to traditionally cooked Eogeul-tang. In conclusion, the study results promote the functionality of collagen as well as the increased quality of Eogeul-tang added with cow gristle manufactured by traditional cooking methods.

• Korean Journal of Food Science and Technology
• /
• v.50 no.3
• /
• pp.316-323
• /
• 2018

This study aimed to analyze the effect of packaging gas type on the quality characteristics of dried persimmon during a 60-day storage period. The samples were stored at 10 and $-10^{\circ}C$. Experimental samples were either untreated (CON) or packed with carbon dioxide ($CO_2$), nitrogen ($N_2$), or argon (Ar) gases. In terms of the CIE $a^*$ (redness) and $b^*$ (yellowness) values, the least changes were observed in the Ar package. The color difference observed in the $N_2$ package was found to be the highest at $-10^{\circ}C$. Ar and $CO_2$ packages showed the highest and lowest water content, respectively, at $10^{\circ}C$. Sensory evaluation showed a high score for Ar packages. At $10^{\circ}C$, the score of the Ar package was the highest until day 40 and that of the $CO_2$ package was the highest from day 40 to 60. At $-10^{\circ}C$, the score of the Ar package was the highest. These results show that $N_2$- and Ar-modified packaging is the most desirable, thus suggesting its application in actual market.