• Journal of the Korean association of regional geographers
• /
• v.4 no.2
• /
• pp.31-47
• /
• 1998

This paper deals with the historical geography of land-use and agriculture along the Lower Nam-River floodplains. The reclamation process of the river floodplains, the cultivation methods on the reclaimed lands, and the land-use patterns and processes are investigated. The Nam River, one of the major tributaries of the Nakdong River, flows through the boundary between Ham-An and Eu-Ryong Guns. Larger floodplains are located in Ham-An Gun. The floodplains of Ham-An Gun have been surveyed intensively in this study. In South Korea, the alluvial plains, mostly located along the river valleys, have been reclaimed to provide fertile agricultural lands. Those along the upper river valleys were reclaimed before those along the lower river valleys. The flood-plains of Han-An Gun were reclaimed to be the largest agricultural lands of the Gun. The natural levees along the Lower Nam-River Valley were identified before the reclamation processes but now hardly identified. Relatively larger floodplains are located along the tributary streams of the Nam River. Often there are low-lying back swamps between the natural levees and the hills/mountains that rise above the floodplains. The back swamps, called 'natural bog lands' in this region, have been reduced in size and in number through reclamation for the purpose of agricultural and industrial land-uses. Now about ten 'natural bog lands' are found in the Ham-An floodplains, and some of them are being reclaimed for the industrial land-use. This study suggests the emergent need of conservation for the remaining 'natural bog lands' in terms of ecology. Seven agricultural fields of large size, originated from the Nam-River floodplains, are identified in this study: Kun(큰들), Chung-Am(정암들), Chang-chi(장지들), Baek-San(백산들), Ha-Ki(하기들), Gu-Hae(구혜들), and Chang-Po(장포들) fields. The Kun field was reclaimed during the Japanese control and the Gu-Hae, in the 1950s. All of those except the above two fields were reclaimed after the mid-1960s. The Nam-River Dam in Chinju, completed in 1969, contributed the reclamation processes along the Lower Nam-River floodplains. The rice acreage of the region has been reduced slowly since 1970 but the rice production of the region has been relatively stable (Table 4). Rice culture had been the most important agriculture on the reclaimed lands for decades before the greenhouse vegetable cultivation became more important in the 1980s. Among the vegetables cultivated in the greenhouse, the watermelon is the dominantly leading one. Watermelons are usually harvested two or three times in a year though it is possible to harvest four times in one year. The rotation of watermelons and rice is common in the region. It is known the physical conditions of the Nam-River floodplains in Ham-An Gun is the most suitable for watermelon cultivation in South Korea.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.8
• /
• pp.367-377
• /
• 2017

This study examined the effects of the salinity of seafood wastewater on the sulfur denitrification process. An examination of the denitrification efficiency showed that the optimal EBCT was 1hr at an influent T-N concentration of 20mg/L or lower and 2-3hr at an T-N concentration of 30mg/L. An examination of the denitrification efficiency according to the nitrogen load showed that the legal effluent water quality criterion was satisfied when the influent load was maintained within $0.496kg/m^3/day$. On the other hand, the reactor volume increased when this was applied to the site. Therefore, the influent load should be within $0.372kg/m^3/day$ considering the denitrification and economic efficiency. At a load of $0.248{\sim}0.628kg/m^3{\cdot}day$, the k value was $0.0890{\sim}0.5032hr^{-1}$. The batch experimental results according to the $Cl^-$ concentration showed that at an influent nitrogen concentration of 30.0mg/L, the effect of the denitrification efficiency was not large below the salinity of $7,000mgCl^-/L$, but inhibition occurred above $9,000mgCl^-/L$. Calculations of the reaction rate constant according to the $Cl^-$ concentration showed that the reaction rate constant was $0.1049{\sim}0.2324hr^{-1}$ at a raw wastewater concentration of ${\sim}5,000mgCl^-/L$. In contrast, the k value was $0.1588hr^{-1}$ at $7,000mgCl^-/L$ and $0.1049hr^{-1}$ at $9,000mgCl^-/L$.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.7
• /
• pp.1654-1660
• /
• 2009

Two different cutting-oils from H and B companies which are sold as an eco-friendly cutting-oils were selected and the biodegradability of these commercially available cutting-oils was evaluated by the sequencing batch reactor (SBR) processes. The cutting-oil wastes ($H_1$) pre-treated by coagulation/flocculation was used as an influent to SBR. When the F/M ratio was operated 0.04 to 0.08kgCOD/kgMLSS d, removals of $BOD_5$and $COD_{Cr}$were above 97% and 91%, respectively. T-N and T-P removals were above 76% and 81%, respectively. If the diluted cutting-oil wastes ($B_1$) was used as an influent of the SBR, $COD_{Cr}$removals were above 77% at the F/M ratio of 0.01-0.02kgCOD/kgMLSS d. After the cutting-oil wastes was treated by coagulation/ flocculation ($B_2$), $COD_{Cr}$removals was above 85%. If the pre-treated cutting-oil wastes were mixed with a synthetic wastewater ($B_3$) and fed into the SBR in order to mimic the real wastewater treatment plant situation, $BOD_5$and $COD_{Cr}$removals were above 97%, 91%, respectively. T-N and T-P removals were above 79% and 76%. The ratio between $BOD_5$and $COD_{Cr}$, ($COD_{Cr}$-$BOD_5$)/$COD_{Cr}$, indicating the biodegradability of effluent of the SBR, was calculated to 85% and 61%. This means that significant amounts of non-readily-biodegradable organic compounds in the effluent of $H_1$, $B_3$are still present.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.4
• /
• pp.1-7
• /
• 2017

Cobalt silicide was used as a counter electrode in order to confirm its reliability in dye-sensitized solar cell (DSSC) devices. 100 nm-Co/300 nm-Si/quartz was formed by an evaporator and cobalt silicide was formed by vacuum heat treatment at $700^{\circ}C$ for 60 min to form approximately 350 nm-CoSi. This process was followed by etching in $80^{\circ}C$-30% $H_2SO_4$ to remove the cobalt residue on the cobalt silicide surface. Also, for the comparison against Pt, we prepared a 100 nm-Pt/glass counter electrode. Cobalt silicide was used for the counter electrode in order to confirm its reliability in DSSC devices and maintained for 0, 168, 336, 504, 672, and 840 hours at $80^{\circ}C$. The photovoltaic properties of the DSSCs employing cobalt silicide were confirmed by using a simulator and potentiostat. Cyclic-voltammetry, field emission scanning electron microscopy, focused ion beam scanning electron microscopy, and energy dispersive spectrometry analyses were used to confirm the catalytic activity, microstructure, and composition, respectively. The energy conversion efficiency (ECE) as a function of time and ECE of the DSSC with Pt and CoSi counter electrodes were maintained for 504 hours. However, after 672 hours, the ECEs decreased to a half of their initial values. The results of the catalytic activity analysis showed that the catalytic activities of the Pt and CoSi counter electrodes decreased to 64% and 57% of their initial values, respectively(after 840 hours). The microstructure analysis showed that the CoSi layer improved the durability in the electrolyte, but because the stress concentrates on the contact surface between the lower quartz substrate and the CoSi layer, cracks are formed locally and flaking occurs. Thus, deterioration occurs due to the residual stress built up during the silicidation of the CoSi counter electrode, so it is necessary to take measures against these residual stresses, in order to ensure the reliability of the electrode.

• Journal of Climate Change Research
• /
• v.3 no.2
• /
• pp.117-128
• /
• 2012

The Government of South Korea has continued its effort to fixate virtuous circle of economic growth and climate change response to cope with international demands and pressure to commitment for greenhouse gas reduction effectively. Nationally, Korean Government has established "Enforcement of the Framework Act on Low carbon, Green Growth"(2010. 4. 13) to implement national mid-term GHG mitigation goal(30% reduction by 2020 compare to BAU), which established the foundation for phased GHG mitigation by setting up the sectoral and industrial goal, adopting GHG and Energy Target Management System. Also, follow-up measures are taken such as planning and control of mid-term and short-term mitigation target by detailed analysis of potential mitigation of sector and industry, building up the infrastructure for periodic and systematic analysis of target management. Likewise, it is required to establish more accurate, reliable and detailed sectoral GHG inventory for successfully establishment and implement the frame act. In comparison to the $CO_2$ emission, Especially fluorinated greenhouse gases (HFCs, PFCs, $SF_6$) are lacking research to build the greenhouse gas inventories to identify emissions sources and collection of the applicable collection activities data. In this study, with the refrigeration and air conditioning sector being used to fluorine refrigerant(HFCs) as the center, greenhouse gas emission estimation methodology for evaluating the feasibility of using this methodology look over and mobile air conditioning, fixed air conditioning, household refrigeration equipment, commercial refrigeration equipment for the greenhouse gas emissions were calculated. First look at in terms of methodology, refrigeration and air conditioning sector GHG emissions in developing country-specific emission factors and activity data of the industrial sector the construction of the DB is not enough, it's 2006 IPCC Guidelines Tier 2a (emission factor approach) rather than the Tier 2b (mass balance approach) deems appropriate, and each detail by process, sectoral activity data more accurate, if DB is built Tier 2a (emission factor approach) can be applied will also be judged. Refrigeration and air conditioning sector in 2009 due to the use of refrigerant greenhouse gas emissions ($CO_2eq.$) assessment results, portable air conditioner 1,974,646 ton to year, fixed-mount air conditioner 1,011,754 ton to year, household refrigeration unit 4,396 ton to year, commercial refrigeration equipment 1,263 ton to year was estimated to total 2,992,037 tons.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.7
• /
• pp.16-19
• /
• 2019

A thinner film has superior electrical properties and a better amorphous structure. Amorphous structures can be effective in improving conductivity through a depletion effect. Research is needed on the Schottky contact, where potential barriers are formed, as a way to identify these characteristics. $SiO_2/SnO_2$ thin films were prepared to examine the amorphous structure and Schottky contact, $SiO_2$ thin films were prepared using Ar = 20 sccm. $SnO_2$ thin films were deposited using mixed gas with a flow rate of argon and oxygen at 20 sccm, and $SnO_2$ thin films were added by magnetron sputtering and treated at $100^{\circ}C$ and $150^{\circ}C$. To identify the conditions under which the amorphous structure was constructed, the XRD patterns were investigated and C-V and I-V measurements were taken to make Al electrodes and perform electrical analysis. The depletion layer was formed by the recombination of electrons and holes through the heat treatment process. $SiO_2/SnO_2$ thin films confirmed that the pores were well formed when heat treated at $100^{\circ}C$ and an electric current was applied over the micro area. An amorphous $SiO_2/SnO_2$ thin film with heat treatment at $100^{\circ}C$ showed no reflection at $33^{\circ}\;2{\theta}$ in the XRD pattern, and a reflection at $44^{\circ}2\;{\theta}$. The macroscopic view (-30 V

• Food Engineering Progress
• /
• v.21 no.3
• /
• pp.225-232
• /
• 2017

Most of the red ginseng (RG) products contain active substances derived from hot water or alcohol extraction. Since active substances of RG are divided into two types - water-soluble and liposoluble - water or alcohol is needed as an extraction solvent and this leads the different extraction yields and components of the active substances. To overcome the limit, whole red ginseng powder can be used and consumed by consumers. In this study, the physicochemical properties and extractable active substance contents of variable-sized RG powder ($158.00{\mu}m$, $8.45{\mu}m$, and $6.33{\mu}m$) were analyzed, and dispersion stability was measured to investigate the suitable size of RG powder for industrial processing. In the results, no significant difference was found from the changes in color intensity and thiobarbutric acid tests at $4^{\circ}C$, $25^{\circ}C$, and $40^{\circ}C$ for 4 weeks. There was no significant difference on the production of antioxidants and ginsenoside among the samples (p>0.05). In dispersion stability, $RG-158.00{\mu}m$ was precipitated immediately, and the dispersion stabilities between $RG-8.45{\mu}m$ and $RG-6.33{\mu}m$ showed no significant difference. It implies that fine RG is suitable for the production process. With further study, it seemed that the physicochemical effects of RG particle sizes can be clearly revealed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.6
• /
• pp.314-320
• /
• 2021

With the increasing age of motherhood in recent years, attributed to late marriages due to social or environmental factors, the Down's syndrome screening test using biochemical markers has become essential for pregnant women. The process of diagnosing Down's syndrome pregnancy in the high-risk group subjects involves chromosomal analysis, which is performed on samples obtained through invasive procedures such as chorionic biopsy or amniotic fluid. Thus, to reduce unnecessary invasive tests and lower the risk to mother and fetus, it is important to identify a screening test with low risk and high Down's syndrome detection rate. Recently, as the average age of mothers has increased, numerous inspection agencies have classified high-risk mothers as women over the age of 35 years. This study evaluated a total of 36,436 pregnant women aged between 17 to 46 years, and who requested prenatal screening at an inspection agency in Yongin in 2018. Test (13,690 people) Four tests were conducted by applying the time-resolved fluoroimmunoassay method using the direct sandwich and indirect sandwich technology, and the immunoassay method using the sandwich method. We aimed to confirm the difference in positivity rate with increasing age of the subjects. We believe that in future, data obtained from this study will be very useful for the prevention and treatment of Down's syndrome risk at varied inspection institutions, and for prospective mothers.

• Journal of Korean Society of Forest Science
• /
• v.100 no.3
• /
• pp.522-534
• /
• 2011

The aim of this study is to draw forth the tasks for establishing the right of native biology in Korea through the case study on 'Access on genetic resources and Benefit Sharing'. For this purpose, this study decided on its research subject by selecting Hoodia, on which ABS treaty was made the most recently, through the examination of the representative ABS precedents on plant species. This study analyzed the process background of ABS on Hoodia, and compared & analyzed the ABS procedures of 'Bonn Guidelines' adopted by the 6th Conference of the Parties of the Convention on Biological Diversity in 2002 and Hoodia case. Together with the ABS major issues in common drawn as a result of this analysis, and "Nagoya Protocol" adopted by the 10th Conference of the Parties of the Convention on Biological Diversity, this study intended to shed a light on the impending tasks which Korea faces at present and its role relationship. The research results are as follows: 1. It is required that species habitats should be divided based on biological classification and its subsequent community should be established with the development of infrastructure such as a community's independent production, management and monitoring of bio-species. 2. There needs to be a designation of ABS National Focal Point for sharing of ABS-related general information, boosting of implementation of the relevant convention. 3. There needs to be the establishment of ABS convention system consequent on legislative, administrative, political procedures, and designation of the Competent National Authorities for the provision of the format of Prior Informed Consent (PIC) and Mutually Agreed Terms (MAT) and their contents assessment and confirmation. 4. There should be the establishment of integrated management system of ABS-related research and development of forest biological resources and its relevant research projects. 5. There should be information development through the distribution of responsibility and role between the ministries and offices concerned according to bio-resources, and there needs to be efforts in aiming for opening a working group of academic-industrial institutions for developing a mutually interchangeable system. 6. It's required that the efficient access between industrial circles and the people should be promoted by setting up ABS support center of biological resources in ministry and office's charge. 7. There should be a selection of a national supervisory organization for securement of the right of a local community and monitoring of ABS convention implementation, and a countermeasure system for preventing outflow of forest bioresources. Conclusively, it's judged that it will be possible to inquire into the countermeasures for the establishment of the native forest biology dominion through such research results.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.139-147
• /
• 2021

Livestock manure is used as an organic fertilizer to replace chemical fertilizers after sufficient fermentation in an aerobic bioreactor. On the other hand, liquid manure disposal problems occur repeatedly because soil spraying is restricted during the summer when the crops are growing. To use liquid fertilizer (LF) as an additional nutrient source for crops, it is necessary to reduce the amount of suspended solids (SS) in the liquid fertilizer and secure stability problems against pathogenic microorganisms. This study examined the effects of the simultaneous SS removal and E.coli sterilization in the LF using the microbubble (MB) generator (FeMgO catalyst insertion). The remaining SS were further removed using the integrated microbubble and microfilter system. During the floating process in the MB device, the SS were removed by 57.9%, and the coliform group was not detected (16,200→0 MPN/100 mL). By optimizing the HRT of the integrated system, the removal efficiency of the SS was improved by 92.9% under the 0.1h of HRT condition. After checking the properties of the treated LF, 64.5%, 70.1%, 54.9%, and 51.5% of the TCOD, SCOD, PO4-P, and TN, respectively, were removed. The treated effluent from such an integrated system has a lower SS content than that of the existing LF and does not contain coliforms; therefore, it can be used directly as an additional fertilizer.