• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.4
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• pp.21-28
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• 1986

Conversion of anaerobic mesophilic digestion to thermophilic range has been investigated using a synthetic sludge. When temperature was raised at a rate of 2, 1, and $0.5^{\circ}C$ per day with continuous feeding, a lower reaction rate was observed with a high rate of temperature change. Although methane fermentation ceased completely for an digesters at thermophilic temperature, acid fermentation continued. Methane fermentation was never achieved even with neutralization during 6 months of resting. The methane formers were completely inactivated by the temperature shock and accumulation of volatile acids due to continuous feeding, while the acid formers lost biological activity quickly, but gradually acclimated to a high temperature. When temperature was raised without feeding, successful thermophilic digestion was achieved with 1 day of resting at thermophilic temperature at a rate of $1^{\circ}C$ per day, and also achieved with 20 days of resting at a direct increase. Conversion to a thermophilic range is easily achieved with resting. A short period of resting is required at a low rate of temperature increase, while a long period of resting enough to balance methane formers with acid fermers makes a conversion possile when temperature is raised at a high rate. Soured thermophilic digesters were recovered after seeding of mesophilic sludges, and sludge seeding could be a good method of start-up, conversion, or recovery of a thermophilic digester. Significant amount of thermophiles seemed to be present in the mesophilic digesters.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1135-1146
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• 2015

This thesis aims to improve the safety of bicycle traffic for activating the use of bicycle, main means of non-powered and non-carbon transportation in order to cope with worldwide crisis such as climate change and energy depletion and to implement sustainable traffic system. In this regard, I analyzed the problem of bicycle roads currently installed and operated, and developed the bicycle accident forecasting model. Following are the processes for this. First, this study presented the current status of bicycle road in Korea as well as accident data, collect the data on bicycle traffic accidents generated throughout the country for recent 3 years (2009~2011) and analyzed the features of bicycle traffic accidents based on the data. Second, this study selected the variable affecting the number of bicycle accidents through accident feature analysis of bicycle accidents at Jeollanam-do, and developed accident forecast model using the multiple regression analysis of 'SPSS Statistics 21'. At this time, the number of accidents due to extension per road types (crossing, crosswalk, other single road) was used. To verify the accident forecast model deduced, this study used the data on bicycle accident generated in Gwangju, 2011, and compared the prediction value with actual number of accidents. As a result, it was found out that reliability of accident forecast model was secured through reconciling with actual number of cases except certain data. Third, this study carried out field survey on the bicycle road as well as questionnaire on satisfaction of bicycle road and use of bicycle for analysis of bicycle road problems, and presented safety improvement measures for the problems deduced as well as bicycle activation plans. This study is considered to serve as the fundamental data for planning and reorganizing of bicycle road in the future, and expected to improve safety of bicycle users and to promote activation of bicycle use as the means of transportation.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.5
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• pp.134-147
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• 2014

Pleasure grounds, which were introduced during the Japanese colonial era, were places for organizing new amusement activities, and developed into a large-scale private spaces and a new type of public space at the same time. This study explores the scenery and accommodations of pleasure grounds and the changes of the amusement culture through the Wolmido Pleasure Grounds, which was a typical pleasure grounds of the time. At that time, Wolmido became a comprehensive amusement/entertainment place with many elements of both Western and Japanese pleasure grounds such as exotic buildings harmonized with trees, a beach, a seaside school, public playing field, and zoo constructed on the Island. Wolmido Pleasure Ground, which was connected with Kyungsung by Kyungin railroad during the Japanese colonial era, is a good example showing the process of the popularization and commercialization of the amusement culture. The process of popularization of amusement shows the spreading of the enjoyment of leisure time with amusement activities through appreciating the beautiful scenery of the pleasure grounds among various social classes. The caste system was broken and anyone could use the pleasure grounds by paying the fee, of which there were many kinds, so the distinction between genders and the different classes, such as the Chosun people and Japanese, regarding amusement in pleasure grounds disappeared gradually. Also, pleasure grounds were a place for Western hobby-sports activities and were the means to generalize collective and dynamic activities through summer school and various sport games. At the same time, there were places for deviation from the existing social norms when it was combined with entertainment facilities. The commercialization of amusement took place in the form of an artificial entertainment culture within an artificial environment. First, the scenery was artificially constructed and this scenery created the image of paradise such as 'captivating summer vacation spot' and 'water kingdom'. This was the result of the combined intentions of the colonial authority, the railroad company and the amusement corporation to produce economic profits and encourage development in the area. Second, an artificial spectacle was constructed using nature as the backdrop. Buildings of various styles created a modernized and exotic image when they were combined with each other. Artifacts such as breakwaters and arcades created new attractions for people that enabled them to view both nature and the crowds from a whole different perspective. Third, pleasure grounds contributed to the advent of passive users who would just follow the given use and instructions. In this way, one can find the prototype of popular entertainment places of today such as sightseeing complexes, amusement parks, and theme parks through the construction of amusement grounds as a place for providing dynamic activities.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.81-91
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• 2020

As part of method for ecologically utilizing abandoned paddy, potential of the abandoned paddy as a target site for ex-situ conservation of 9 endangered species of different life form was confirmed by considering the nature of rice paddy. In order to create Dum-bung, a component of traditional Korean rice paddy, a part of the abandoned paddy was modified to change the water environment. The seeds, asexual reproductive and sexually reproductive individuals of each endangerd species were transplanted into the abandoned paddy to observe the survival rate and phenological response for 1 year, and then monitored for 2 years. As a result, Hydrophyte 4 taxa (Euryale ferox, Saururus chinensis, Dysophylla yatabeana, Menyanthes trifoliata), Geophyte taxa 1 (Epilobium hirsutum), and Hemicryptophyte taxa 1 (Cicuta virosa) could be introduced into the abandoned paddy. In particular, Euryale ferox, Dysophylla yatabeana, and Menyanthes trifoliata should be introduced into Dum-bung, and Saururus chinensis, Epilobium hirsutum, and Cicuta virosa should be introduced into paddy wetland. Growth of Euryale ferox and Brasenia schreberi was inhibited by herbaceous species, and the growth of Epilobium hirsutum was inhibited by herbivores. Therefore, in order to help efficient settlement of endangered plants introduced in abandoned paddy, it is necessary to remove herbs that inhibit growth and to manage herbivores. In addition, it is necessary to prevent the collapse of paddy bank by planting on the paddy field trees or herbaceous forming vegetation mat. When using abandoned paddy ecologically, it is effective to diversify the moisture environment by creating a Dum-bung to increase biodiversity.

• Journal of Conservation Science
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• v.27 no.3
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• pp.333-344
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• 2011

Cleaning of foreign matter and corrosion products on surface among conservation treatment of iron artifacts is an important part for looking up a original form. The sand blaster is the most popular equipment when it removes the foreign matter and corrosion products on iron artifacts surface. Current foreign matter and corrosion products equipment, which mostly uses, is sand blaster. Glass dust which sprayed from sand blaster is harmful and causing environmental pollution. In order to solve these problems, we investigated the $CO_2$ snow cleaning that use a eco-friendly equipment to apply for cleaning foreign matter and corrosion products on surface of iron artifacts. It examined by using sand blaster and $CO_2$ snow cleaning to aged steel coupon and iron artifacts. In case of aged steel coupon, the result showed that the sand blaster and $CO_2$ snow cleaning methods were similar to the degrees of cleaning foreign matter and corrosion products, through surface roughness, color measurement and SEM. $CO_2$ snow cleaning applied to aged steel coupons weren't worn out the surface in comparison with sand blaster by SEM. When applied to the iron artifacts, power nozzle of the $CO_2$ snow cleaning was an excellent cleaning effect that surface wern't worn out in comparison with sand blaster. And, it showed that internal structure change of metal was no found before and after cleaning by X-ray radiography. Consequently, we confirmed that cleaning of the sand blaster and power nozzle of $CO_2$ snow cleaning were similar to the effect. But, it's very careful to use this method because of high outlet pressure of power nozzle for applying to the iron artifacts. As a result of experiments, it could be found that the cleaning methods should be selected depending on internal state of the artifacts.

• Analytical Science and Technology
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• v.24 no.3
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• pp.193-199
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• 2011

The purpose of this experiment is to evaluate the stability of products according to the storage methods, the period of use, and the diurnal variations through the short term stability experiment of recombinunt protein A (rProtein A) produced in AP Tech Co. That is, we investigated how long the stability of the products would last, when we used the samples frozen at $-20^{\circ}C$, which is one of the storage conditions of the produced rProtein A and then kept them refrigerated at $4^{\circ}C$. The experiment was conducted for 8 weeks and 6 experiment points were established. The experiment was done by thawing the samples frozen at $-20^{\circ}C$ at room temperature, and then refrigerating them at $4^{\circ}C$. In addition, experiments for endotoxin, bioburden, HPLC purity, and concentration were conducted. As a result of the experiment, 0.5 EU/mg endotoxin was detected both at the beginning and at the 8th week and bioburden was not analyzed. In the case of purity, it showed 99.23~99.90% at 210 nm (RSD% 0.23%) and 100% at 280 nm, which meant the change into other materials didn't happen and there was no material degradation characteristics. Finally, we also found the fact that the concentration stayed stable at 55.15 mg/mL (RSD% 0.55%) both at the beginning and at the end. From the experiment results, we were able to conclude that the stability at the condition to store rProtein A at 4 oC for 8 weeks was procured without producing microorganisms or having material degradation characteristics.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.4
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• pp.118-127
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• 2005

The best way to treat livestock manure is a recycling the manure to arable land as an organic fertilizer. In this study, fermented cow manure compost and pig manure compost were used as a raw materials for pelletizing. The changes of physicochemical properties of each composts and pellets were investigated. The aim of this research was to improve availability of livestock manure compost. In pelletizing process of fermented livestock manure compost, the optimal water content to make pellet was around 40%. When clay was mixed by volume more than 15% as a bonding agent, the condition of pelletizing process was beginning to improve. On a dry matter basis, the contents of N, P and K of fermented pig manure compost were 2.05%, 1.89% and 1.31%, respectively. After pelletizing, the contents of compost pelleted with the pig manure compost were 1.96% 1.73% and 0.89%, respectively. The same parameters of cow manure compost were 2.52%, 1.01% and 2.98%, respectively. After processing, the contents of compost pelleted with the cow manure compost were 2.45%, 1.10% and 2.93%, respectively. After pelletizing, there were little change in the content of heavy metals such as Pb, Cd, As and Hg. When pelleted compost dried naturally was submerged in water, it was completely dissolved in 30 minutes. On the other hand, Pelleted compost dried with the mechanical convection oven set $70^{\circ}C$ for 24 hours was completely dissolved in 960 minutes. The volume and weight of pelleted compost were decreased with time. After 30 days of storing, the weight of pelleted compost was decreased by 15% compared with its original weight. The volume of it was decreased by 17~25% in the same time.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.253-262
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• 2015

The sustainability of Cypripedium japonicum, a rare plant designated by the Korea Forest Service, is threatened due to artificial factors such as habitat loss and climate change etc. and internal factors such as changes in biological properties of the habitat etc. but conservation research has not been performed in South Korea. The objective of this study is to establish the species conservation strategies by analyzing the characteristics of their habitats, including: 1) Population characteristics, and 2) habitat analysis of the vegetation and abiotic environments. From April to September, 2014, population characteristics [density (stems $m^{-2}$), flowering rate (%), and leaf area ($cm^2$)] in Cypripedium japonicum habitats such as Chuncheon (CC), Hwacheon (HC), Muju (MJ), and Gwangyang (GY) and vegetation characteristics (plant sociological research and ordination analysis), and abiotic environments [temperature ($^{\circ}C$), relative humidity (%), transmitted light ($mol{\cdot}m^{-2}{\cdot}d^{-1}$) and canopy openness (%)] were measured. Cypripedium japonicum was mainly distributed at elevation 450 to 990 m and 5 to $30^{\circ}$ slope. Slope direction was shown as 0 to $110^{\circ}$. Habitats temperature (mean $18.94^{\circ}C$) was well matched to seasonal changes. Differences among sites showed greater level according to latitude difference. It showed the highest in habitat, GY located in the South. On the other hand, relative humidity (77.38%) didn't show much difference among sites. The average degree of canopy openness was 18.17%. It showed the highest at HC (22.1%) and the lowest at MJ (16.1%). The average degree of transmitted light was $9.1mol{\cdot}m^{-2}{\cdot}d^{-1}$. It showed the highest at CC ($10.6mol{\cdot}m^{-2}{\cdot}d^{-1}$) and the lowest at GY ($6.87mol{\cdot}m^{-2}{\cdot}d^{-1}$). Chlorophyll content showed average 26.12 SPAD. It showed the highest at MJ (30.64 SPAD value) and the lowest at HC (23.69 SPAD value). Leaf area was average $253.35cm^2$. It showed the highest at CC ($281.51cm^2$) and the lowest at HC ($238.23cm^2$).

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.2
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• pp.103-109
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• 2009

Soils originated from limestone, located at the southern part of Kangwon province and Jecheon, Danyang of Chungbuk province are mainly composed of fine texture, and have different properties from soils originated from granite and granite gneiss, especially for water movement. This study was conducted for classification of hydrologic soil group (HSG) of soils originated from limestone by measuring the infiltration rate of surface soils and percolation rate of sub soils. Soils used for the experiment were 6 soils in total : Gwarim, Mosan, Jangseong, Maji, Anmi and Pyongan series. Infiltration and percolation rate were measured by a disc tension infiltrometer and a Guelph permeameter, respectively. Particle size distribution and organic matter content of the soils were analyzed. HSG, which was made by USDA NRCS(National Resources Conservation Service) for hydrology, of Gwarim series with O horizon of accumulated organic matter was classified as type A which show the properties of low runoff potential, rapid infiltration and percolation rate. HSG of Mosan series, which has high gravel content and very rapid permeability, was classified as type B/D because of the impermaeble base rock layer under 50cm from surface. HSG of Jangseong series with shallow soil depth was classified as type C/D owing to the impermaeble base rock layer under 50cm from surface. HSG of Maji series was type B, and HSG of Anmi series used as paddy land was type D because of slow infiltration and percolation rate caused by the disturbance of surface soil by puddling. HSG of Pyeongan series having a sudden change of layer in soil texture was type D because of the slow percolation rate caused a the layer.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.329-344
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• 2017

This study was carried out to investigate the hot pepper yield, chemical properties of soil and distribution of animalcule with split irrigation and input of organic matter under no-tillage hot pepper green house condition. After experiment, soil pH maintained range of 5.6~6.2 in whole treatments. Organic matter content of soil was range of $32{\sim}42g{\cdot}kg^{-1}$. Soil salinity (EC) content of soil was range of $1.0{\sim}2.7dS{\cdot}m^{-1}$. Exchangeable cations in soil were range of $0.08{\sim}0.24cmol^+{\cdot}kg^{-1}$ in K, $9.5{\sim}12.8cmol^+{\cdot}kg^{-1}$ in Ca, and $2.7{\sim}3.2cmol^+{\cdot}kg^{-1}$ in Mg. Avaliable phosphorus ($P_2O_4$) content in soil was range of $1,011{\sim}1,137mg{\cdot}kg^{-1}$. Yield of pepper was more decreased in treatment of soybean cake fertilizer than no-treatment of soybean cake fertilizer. Yield of pepper in treatment of soybean cake fertilizer was increased at 33% of standard fertilizer application. Yield of pepper in no-treatment of soybean cake fertilizer was increased at 33% and 66% of standard fertilizer application. Number of fruits was increased range of 12.5~34.9% at half division irrigation compared with whole quantity irrigation. Yield of pepper was increased range of 13.5~34.4% at half division irrigation compared with whole quantity irrigation. Nine index of nature status and 271 Individual were captured in treatment of soybean cake fertilizer. Five index of nature status and 54 Individual were captured in treatment of soybean cake fertilizer. Nature status for environmental change as index organism was 11 points and 5 points, at treatment of soybean cake fertilizer and no-treatment of soybean cake fertilizer, respectively.