이온선택성 미세전극 센서를 위한 토양화학 다성분 분석용 최적 침출액종 선발

신국식 한경대학교 생물환경·정보통신전문대학원 2008 국내석사

본 연구는 현장에서 치환성양이온(K+, Ca2+, Mg2+ 및 Na+) 와 무기태질소(NH4+와 NO3-)를 신속히 분석하고자 소자형 이온선택성 미세전극 동시분석에 적합한 단일 침출액종을 선발하고자 하였다. 이를 위해 모재가 상이한 20개의 토양과 다수의 논과 밭토양 및 시설하우스 토양 60점을 공시하고, 1M LiCl외 8개의 유망한 토양 침출액을 선정하여 그 중에서 가장 적합한 침출액종을 선발하는데 목적이 있었다. 1. 동시분석용 단일 침출액과 표준 침출용액(1M NH4OAc)의 치환성양이온의 ICP 분석결과치 사이 직선회귀는 모든 침출액종에서 고도의 유의성이 있는 결정계수(R2) 값을 나타 내었다. 2. 동시분석용 단일 침출액과 표준 침출용액(2M KCl)의 무기태질소의 켈달증류 분석치 사이에서의 결정계수(R2) 크기는 Mehlich1(0.9895) = 0.1M HCl(0.9860) > 1M LiCl(0.9770) > 0.5M BaCl2(0.9235) 순 이었다. 3. 다양한 침출액 하에서 이온선택성 전극의 분석결과 0.01M HCl과 1M LiCl이 모든 대상 화학종에 대하여 가장 Nernst이론값에 근접하였다 4. NH4+이온은 K+이온과 혼재할 때 K+이온의 간섭으로 매우 낮은 선택성을 나타내었다. 또한, Mg2+이온은 Ca2+이온과 혼재할 때 이온선택성 전극의 선택성이 낮아 분석이 불가 하였다. 5. 결론적으로 소자형 이온선택성 미세전극을 위한 최적의 침출액종및 분석방법은 0.1M HCl로 침출하여 10배 희석 측정하거나 또는 0.01M HCl로 직접 침출하여 측정하는 하는 것이라 판단되었다. The rapid analysis of ionic species in soil solution is very important, but analysis of ionic species is very difficult and consume many times and expense, because ionic species in soil solution is variable and the pre-treatment procedure for quantitative analysis is different to each ionic species by whether ionic characteristics is organic or inorganic, cation or anion, and heavy metal or not. In this research to rapidly analyze the variable ionic species in soil solution the extractive ability of soil extraction solutions was tested, and the composition of soil extraction solution for multi-analysis of ionic species was investigated. The twenty soils that have different origin were used in this experiment. To test the extractive ability of soil extraction solutions nine different extraction solutions were used such as 1M LiCl, 1M LiOAc, 1M NaOAc, 0.1M HCl, Mehlich I, Mehlich II, Mehlich III, 0.5M BaCl2, 0.5M BaOAc. And the amount of ionic species at extracted soil solution is analyzed by ISE microsensor. The analysis data were statistically analyzed by liner regression. Also the soil extraction solution that more quantitatively represent soil ionic state was selected. 1. The linear regression coefficients between multi-elements extracting solution and 1M NH4OAc solution in the values of exchangeable cations are highly significant in 1% level. 2. The coefficient of liner correlation(R2) for extracted inorganic nitrogens(etc. NH4+, NO3-) between 2M KCl solution and tested extraction solution decreased in order of Mehlich I(0.9895) > 0.1M HCl(0.9860) > 1M LiCl(0.9770) > 0.5M BaCl2(0.9235) in the comparison of extractive ability. 3. In the measured data by ISE, the results that are adopting 0.01M HCl and 1M LiCl as extraction solution showed the most similar values with the slope(mV/log[M] = 59.19) of Nernst equation. 4. In the measurement of ionic species in soil solution by ISE When, The presence of K+ and Mg2+ ion interfered measurement of NH4+ ion and Ca2+ ion respectively. The sensitivity for NH4+ ion and Ca2+ ion were very low in the measurement by ISE. 5. The adoption of 0.01M HCl solution as soil extraction solution was the best soil extraction method for the ionic species measurement by the ISE microsensor. And the alternative method that dilutes as ten times the extraction solution by 0.1M HCl solution was possibly recommended.

농축산 바이오매스 메탄생산퍼텐셜과 메탄생산 요인 해석

신국식 韓京大學校 2013 국내박사

Due to the current efforts put into reducing the amount of CO2 to cope against the climate changes, interests about biomass resources are increasing. Biomass resources are the energy which can continuously be circulated and possess carbon neutral properties as they do not increase the amount of CO2. In terms of biomass conversion technology, direct combustion(pellet, chip), diverse energy conversion technology such as thermochemical conversion (hydrothermal experiment, carbonization, hydrothermal carbonization etc.), and biological conversion(biogas, bio-ethanol) are being applied, but in case of biomass wastes occurring in the agricultural field, biogas technology is being evaluated as the most commercialized technology. Anaerobic digestion technology which apply the domestic agricultural biomass are being evaluated as in the early stage of supply in the empirical commercialization, and even though about 15 locations are currently in-operation, all the facilities are localizing piggery slurry and food wastes as the raw material. Therefore, this study researched and calculated the occurrence units of biomass waste from 36 types of vegetables and animals in the agricultural field and analyzed the anaerobic digestion characteristics according to each biomass characteristic. Additionally, through the analysis of biochemical methane potential which applies the batch anaerobic reaction, anaerobic organic matter decomposition efficiency and biochemical methane potential of various agricultural biomass were analyzed. In order to do so, foreign biochemical methane potential standard method(Germany VDI4630, America ASTM) were examined and standard method needed for the evaluation of anaerobic decomposition efficiency of vegetable and animal raw materials were developed and established. Additionally, agricultural anaerobic microbial reactions were analyzed through the kinetics analytical techniques and influence factors of anaerobic digestion through statistical analysis were derived and analyzed. As a result, biochemical methane potential of agricultural biomass waste was displayed as 0.220∼0.646 Nm3/kg-VSadded for animals and 0.207∼0.417 Nm3/kg-VSaddedfor vegetables and displayed about 30~70% of decomposition efficiency compared to analytical biochemical methane potential. In terms of anaerobic decomposition efficiency of organic matters, regulation VDI4630 and method of constraint suggested in this study have been compared for animal raw material. It has been displayed that it can increase the accuracy to the maximum of 0.9%∼3.1% and the optimal S/I ratio of anaerobic digestion was evaluated as 0.5. Furthermore, as a result of conducting statistical analysis, representing factors which cause great influence on anaerobic digestion were displayed as crude fat(either extract, EE), crude fiber(crude fiber, CF), nitrogen(N), and copper(Cu). It has been evaluated that crude fat acts from lag phase time, crude fiber acts from the decrease of biochemical methane potential, and nitrogen and copper act through restraints of anaerobic digestion.

자동차 크랭크 軸用 鋼材의 棒對棒 同種材 摩擦熔接의 疲勞强度 特性 및 AE評價에 관한 硏究

신국식 釜慶大學校 1997 국내석사

연료전지를 이용한 소방비상전원설비의 적용에 관한 연구

신국식 경기대학교 공학대학원 2020 국내석사

국내 건축물은 초고층화, 지하화 등으로 더 복잡하고 더 다양한 형태로 건설되고 있다. 이로 인해 건축물에 필요한 소방비상전원용량 또한 건축물의 규모와 높이, 소방대의 화재진압시간 등을 고려하여 더 많은 소방비상전원용량을 필요로 하고 있다. 국가화재안전기준(NFSC)에서도 소방비상전원용량을 기존 30분에서 60분 이상(50층 이상 건축물)으로 규정하고 있다. 소방비상전원설비의 종류에는 자가발전설비, 축전지, 비상전원수전설비, 전기저장장치가 있으며, 전기저장장치는 최근 소방법에 추가된 비상전원설비로 외부 전기에너지를 저장해 두었다가 필요할때 전기를 공급하는 장치이다. 전기저장장치는 순간적인 전력변화에는 매우 우수하지만 충전용량의 한계로 지속적 전력공급이 어렵다는 단점을 가진다. 자가발전설비는 내연기관을 이용하여 전기를 생산 공급하는 장치로 연료공급에 따라 지속적 전원 공급 및 용량이 큰 소방부하에 적합한 비상전원설비이다. 하지만 화석연료 사용으로 인해 지구온난화 물질인 CO 및 각종 유해물질 발생으로 환경문제를 야기 시킨다. 이에 반해 연료전지는 수소와 산소의 화학에너지를 이용한 전기화학반응에 의해 직접 전기에너지로 변환시키는 발전설비로 공해물질 배출이 없는 친환경적 청정 에너지이다. 또한 소용량에서 대용량까지 다양한 전력공급에 적합한 발전설비이다. 이에 본 연구에서는 연료전지의 기본이론과 국내외 개발 현황과 발전 현황을 조사․분석하였으며, 국내 건축물에 적용 가능한 연료전지 종류와 성능을 비교 분석하였다. 이를 바탕으로 건축물의 용도에 적합한 연료전지의 종류 및 시스템을 선정하고 소방비상전원설비로서 타당성을 평가하고자 하였다. 연구를 수행한 결과, 고분자 전해질 연료전지(PEMFC)가 가정용 및 중소형 일반건축물에 가장 적합하였다. 기동시간은 3분∼ 60분으로 개질기 없이 순수한 수소를 사용하는 경우, 기동시간은 3분이고, 개질기를 통해 수소가 공급 된 경우, 기동시간은 60 분이었다. SOFC (Solid Oxide Fuel Cell, 고체산화물 연료전지)는 “800 ℃ 이상의 고온으로 운전되는 특성상 기동시간이 36시간 소요된다. 그러나 발전 효율이 타 종류에 비해 매우 높기 때문에 많은 전력을 사용하는 건물 및 발전소에 적합하였다. 발전시설의 경우 PAFC(Phosphoric Acid Fuel Cell, 인산형 연료전지)와 MCFC(Molten Car bonate Fuel Cell, 용융탄산형 연료전지)가 적합 하였으며 열과 전기를 동시에 사용하는 열병합발전소에 특히 경제성이 높았다. 고분자 전해질 연료전지(PEMFC)의 경제적 타당성은 소형열복합발전의 대규모 공동주택이 높은 경제적 효율을 보였다. 반면에 가정용 주택은 경제성이 가장 낮았다. 일반건축물의 경우에는 정부의 신재생에너지 지원제도 등의 지원정책으로 경제적 타당성을 확보했지만, 가정용주택은 정부의 지원제도가 없어 발전에 필요한 가스요금이 전기사용량 요금보다 높아 경제성이 가장 낮았다. 유지 보수 측면에서는 태양광 등 타 신재생에너지 보다 우수한 성능과 고밀도 에너지를 생산하는 시스템으로 용량대비 설치면적이 적어 건물에 매우 유용하였다. 그러나 STACK, 개질기, BOP 와 같은 핵심 부품의 기술력 보완이 필요하였다. 따라서 국내 연료전지의 기동성과 경제성, 유지 보수 및 수명에 대한 지속적인 연구개발을 통해 화재로부터 국민의 생명과 재산을 보호하는 신뢰도 높은 소방비상전원설비로 적용되어야 할 것이다. Domestic buildings are being constructed in more complex and more diverse forms, such as skyscrapers and undergrounds. For this reason, the fire emergency power capacity required for the building also requires more fire emergency power capacity considering the size and height of the building and the fire extinguishing time of the fire brigade. The National Fire Safety Standard (NFSC) also regulates the emergency fire-fighting power supply capacity from 30 minutes to 60 minutes (over 50 stories).Self-power generation facilities, storage batteries, emergency power receiving facilities, and electric storage devices are included in the types of fire emergency power facilities. to be. The electric storage device is very good for instantaneous power change, but has the disadvantage that it is difficult to continuously supply electricity due to the limitation of the charging capacity. The self-powered facility is a device that produces and supplies electricity using an internal combustion engine, and is an emergency power facility suitable for continuous power supply and large-capacity firefighting loads according to fuel supply. However, the use of fossil fuels causes environmental problems due to the generation of global warming materials, CO and various harmful substances. In contrast, a fuel cell is a renewable energy source using hydrogen, and is a power generation facility that generates electricity by generating electricity and heat. It is also a power generation facility suitable for various power supply from small to large capacity. Accordingly, this study investigated and analyzed the basic theory of fuel cells, domestic and foreign development status and power generation status, and compared and analyzed the types and performance of fuel cells applicable to domestic buildings. Based on this, a fuel cell type and system suitable for the purpose of the building were selected and the feasibility of evaluating it as a fire emergency power supply system was evaluated. As a result of the research, a polymer electrolyte fuel cell (PEMFC) was the most suitable fuel cell for home and small to medium-sized general buildings. The starting time was 3 minutes to 60 minutes. When pure hydrogen was used without a reformer, the startup time was 3 minutes, and when hydrogen was supplied through the reformer, the startup time was 60 minutes. SOFC (Solid Oxide Fuel Cell), “is operated at a high temperature over 800℃ and takes 36 hours to start. However, the power generation efficiency is very high compared to other types, making it suitable for buildings and power plants that use a lot of electricity. For power generation facilities, PAFC (Phosphoric Acid Fuel Cell) and MCFC (Molten Car bonate Fuel Cell) were suitable, and economic efficiency was particularly high for a combined heat and power plant that uses heat and electricity simultaneously. The economic feasibility of the polymer electrolyte fuel cell (PEMFC) showed high economic efficiency in the case of small-scale thermal power generation in a large-scale apartment complex. On the other hand, residential homes had the lowest economic feasibility. General buildings and fuel cells for power generation have secured economic feasibility through government policy support, but household houses do not have government support, so the gas cost required for power generation is higher than the electricity consumption rate, which is the lowest economic feasibility. In terms of maintenance, the fuel cell is a system that produces higher performance and higher density energy than other renewable energy such as solar power, which is a very useful power generation facility for buildings and is also suitable as an emergency power supply facility. However, it was necessary to supplement the core parts such as STACK, reformer and BOP. Therefore, it must be applied as a highly reliable fire-fighting emergency power facility that protects people's lives and property from fire and power generation through continuous research and development on the start-up time, economy, maintenance, and life of the domestic fuel cell.