Toxic gas emissions are a critical global health concern, responsible for numerous deaths each year. These hazardous gases can cause severe physiological reactions and even death upon exposure. To address this issue, we propose a graphene-Kaptonbased flexible biosensor for non-invasive toxic gas detection. The sensor is designed to accurately detect and identify several harmful gases, including carbon monoxide (CO), fluorine azide ( FN3), hydrogen iodide (HI), nitrogen ( N2), methane ( CH4), nitrous oxide ( N2O), and ozone ( O3). Utilizing the Computer Simulation Technology (CST) Studio Suite 2024, we simulate the detection process, focusing on advanced techniques and miniature flexible structures. The sensor’s active element is a graphene patch embedded within a polyimide (Kapton) film, which allows for precise determination of the RF planar resonant structure’s frequency response. The graphene–Kapton biosensor is shown to have remarkable detection performance, as demonstrated by the results of the simulation, with a diffusivity of 9.09e−08[m2∕S] , an accuracy of 6.62e−13 , and a power loss of 1.5mW . These findings highlight the sensor’s potential as an effective tool for detecting and identifying toxic gases with high precision and efficiency.
In this study, among the indoor lighting sources of a training ship, the fluorescent lamps for lighting in the passageways, emergency fire pump room, refrigerant plant room, steering gear room, and bow hydraulic pump room, which have very high lighting rates, were replaced by 40W fluorescent lamps with 17W and 20W fluorescent lamps with 11W LEDs. The analysis results of replacing the lighting sources with LEDs showed that the power consumption and carbon dioxide emissions were reduced by 62.1% when using shore power.
In this study, numerical modeling on the gas flow and off-gases in the low temperature carbonization furnace for carbon fiber was analyzed. The furnace was designed for testing carbonization process of carbon fibers made from various precursors. Nitrogen gas was used as a working gas and it was treated as an incompressible ideal gas. Three-dimensional computational fluid dynamics for steady state turbulent flow was used to analyze flow pattern and temperature field in the furnace. The off-gas mass fraction and cumulative emission gas of species were incorporated into the CFD analyses by using the user defined function(UDF). As a results, during the carbonization process, the emission of CO2 was the dominant among the off-gases, and tow moving made the flow in the furnace be uniform.
The interest in greenhouse gases (GHG) emitted from all industries is emerging as a very important issue worldwide. This is affecting not only the global warming, but also the environmentally friendly competitiveness of the industry. The fisheries sector is increasingly interested in greenhouse gas emissions also due to the Paris Climate Agreement in 2015. Korean industry and government are also making a number of effort to reduce greenhouse gas emissions so far, but the effort to reduce GHG in the fishery sector is insufficient compared to other fields. Especially, the investigation on the GHG emissions from Korean fisheries did not carry out extensively. The studies on GHG emissions from Korean fishery are most likely dealt with the GHG emissions by fishery classification so far. However, the forthcoming research related to GHG emissions from fisheries is needed to evaluate the GHG emission level by species to prepare the adoption of Environmental labels and declarations (ISO 14020). The purpose of this research is to investigate which degree of GHG emitted to produce the species (swimming crab and snow crab) from various fisheries. Here, we calculated the GHG emission to produce the species from the fisheries using the life cycle assessment (LCA) method. The system boundary and input parameters for each process level are defined for LCA analysis. The fuel use coefficients of the fisheries for the species are also calculated according to the fuel type. The GHG emissions from sea activities by the fisheries will be dealt with. Furthermore, the GHG emissions for producing the unit weight species and annual production are calculated by fishery classification. The results will be helpful to establish the carbon footprint of seafood in Korea.
The characteristics of pollutant emission for non-premixed flames with LCG 8000 and LCG 6000 represented as low calorific gases were investigated by numerical simulation. Commercial software (ANSYS 16.2 - FLUENT) is used to predict 2-D pollutant emission with GRI 3.0 detailed reaction mechanism. In addition, the addition of hydrogen to LCG 6000 was also considered. As result, the flame length and temperature of LHVGs were decreased with decreasing calorific value at the same condition. In addition, NO concentration was decreased as temperature decreased. However, CO concentration for LCG 8000 predicted to be slightly higher than that for methane due to the high propane concentration. In the case of LCG 6000 with added hydrogen, the flame length was the shortest and NO concentration was the highest due to the highest flame temperature, but CO concentration decreased rapidly due to the addition of the carbon-free fuel.
Using first-principles theory, this work investigated the Cu-doping behavior on the N-vacancy of the C3N monolayer and simulated the adsorption performance of Cu-doped C3N (Cu–C3N) monolayer upon two dissolved gases ( H2 and C2H2). The calculations meant to explore novel candidate for sensing application in the field of electrical engineering evaluating the operation status of the transformers. Our results indicated that the Cu dopant could be stably anchored on the N- vacancy with the Eb of − 3.65 eV and caused a magnetic moment of 1 μB. The Cu–C3N monolayer has stronger performance upon C2H2 adsorption than H2 give the larger Ead, QT and change in electronic behavior. The frontier molecular orbital (FMO) theory indicates that Cu–C3N monolayer has the potential to be applied as a resistance-type sensor for detection of such two gases, while the work function analysis evidences its potential as a field-effect transistor sensor as well. Our work can bring beneficial information for exploration of novel sensing material to be applied in the field of electrical engineering, and provide guidance to explore novel nano-sensors in many fields.
The concern on the greenhouse gas emission is strongly increasing globally. In fishery industry section, the greenhouse gas emissions are an important issue according to The Paris Climate Change Accord in 2015. The Korean government has a plan to reduce the GHG emissions as 4.8% compared to the BAU in fisheries until 2020. Furthermore, the Korean government has also declared to achieve the carbon neutrality in 2050 at the Climate Adaptation Summit 2021. However, the investigation on the GHG emissions from Korean fisheries did not carry out extensively. Most studies on GHG emissions from Korean fishery have dealt with the GHG emissions by fishery classification so far. However, follow-up studies related to GHG emissions from fisheries need to evaluate the GHG emission level by species to prepare the adoption of environmental labels and declarations (ISO 14020). The purpose of this research is to investigate which degree of GHG emitted to produce the species (hairtail and small yellow croaker) from various fisheries. Here, we calculated the GHG emission to produce the species from the fisheries using the Life Cycle Assessment method. The system boundary and input parameters for each process level are defined for the LCA analysis. The fuel use coefficients of the fisheries for the species are also calculated according to the fuel type. The GHG emissions from sea activities by the fisheries will be dealt with. Furthermore, the GHG emissions for producing the unit weight species and annual production are calculated by fishery classification. The results will be helpful to understand the circumstances of GHG emissions from Korean fisheries.
본 조사는 국내에서 작물재배용으로 생산 및 시판되는 복합 비료와 축산분뇨 퇴비에 함유된 CO2와 CH4의 양을 개략적으로 알아보고자 실험적으로 검토하였다. 그 결과를 요약하면 다음과 같다. 복합비료의 한 포대에서 계측된 CO2의 농도는 계측한 날짜와 관계없이 평균 약 1,733.3ppm 정도로 일정하게 나타났다. 비료 한 포대당 함유된 양은 0.067kg 정도였고, 비료의 단위 무게는 3.35×10 -3 kg·kg -1 정도였다. 국내에서 농업용으로 출하된 복합비료는 평균 885,750t·yr -1 이었다. 이 양을 기준으로 복합비료 자체에 함유된 CO2의 양은 약 2.9백 만 t·yr -1 정도로 추정할 수 있었다. CH4의 경우, 측정 개시일에 한 포대에 76.8ppm(포대당 2.949×10 -3 kg, 단위 무게당 0.15× 10 -3 kg·kg -1 ) 정도 나타낸 후, 그 이후에는 측정되지 않았다. 퇴비에 함유된 CO2의 양은 구멍의 폐쇄 및 개방 여부에 관계없이 측정 일이나 측정구에 따라 계측기의 최대 측정범위인 10,000ppm을 초과하는 경우도 있었지만, 최대인 10,000ppm 이라고 가정하고 검토하였다. 따라서 최대인 10,000ppm이라고 가정하고 검토한 결과 한 포대당 함유된 양은 0.506kg 정도 였다. 퇴비 구멍의 폐쇄 및 개방 여부에 따라 CH4의 농도가 증감하는 것으로 나타났다. 퇴비 한 포대에 함유된 CH4의 양은 약 2.53kg 정도였다. 이 양을 국내에서 생산된 고형퇴비의 평균 생산량과 비교하면, 약 4.7백만 t·yr -1 이상이 될 것으로 추 정할 수 있었다. 고추재배 포장에서 배출되는 CO2의 양은 측 정 종료 때까지 평균적으로 8,040ppm 정도였다. 나지의 경우, 시간의 경과와 함께 CH4의 농도는 점차 감소하였고, 최대 1,700ppm에서 거의 제로 상태까지 약 50일이 소요되었다.