Herein, we synthesized four sensing materials namely N-MWCNT, N-MWCNT/CMC, N-MWCNT/PANI, and N-MWCNT/PPy, and characterized them using FTIR, XRD, XPS, SEM, and TEM. Then, we studied the effect of polymers such as CMC, PANI, and PPy on the N-MWCNT for the detection of DMMP with a concentration ranging from 2–10 ppm. The results showed that N-MWCNT alone possesses the lowest sensitivity towards 10 ppm DMMP molecules. When the polymers were added to the N-MWCNT, the results showed enhancement in the sensitivity towards the DMMP molecules. The order of highest sensitivity is N-MWCNT/CMC > N-MWCNT/PANI > N-MWCNT/PPy > N-MWCNT.
In this study, the Surface Acoustic Wave (SAW) sensor was designed according to the length of the delay line, and its performance during the detection was studied as the design variable. Dimethyl methylphosphonate (DMMP), which imitates the chemical structure of nerve agent sarin and is relatively less toxic, was used to study the performance of gas detection in which POSS-TU (polyhedral oligomeric silsesquioxane – thiourea) was used as the sensing material. The experiments showed the frequency shift characteristics of the sensors. Among the sensors with the design error values, a specific sensor had the largest difference in the frequency shift between the first and second peaks. Also, both the noise and reactivity were better than other sensors. The fastest reversible characteristics in the recovery time were observed.
Carbon neutrality is now important and inevitable in the 21st century for climate change and global warming, and numerous industries are trying to decrease the emission of greenhouse gases. Also, numerous studies have been followed in the steel industry, and FINEX was first devised and is now used as decreasing 20 % of greenhouse gases during the production of iron. Furthermore, the HyREX that is the production process of direct reduced iron with hydrogen was devised for carbon neutrality by replacing coal with hydrogen. In this study, HyREX was studied for its temperature and the number of cycles with 7 % of hydrogen by simulation using Chemical equilibrium with applications to find optimized conditions since it is challenging to research as an experimental approach due to the problem of cost and size. The optimized condition was defined as the point that reduces all oxygen from iron ore because the rest of iron ore or oxides can cause the problem of purity. The temperature range was set between 800 K to 1200 K as known temperature for the production of direct reduced iron that is below the melting point of iron. The amount of provision of iron was constant as 100 g and the percentage of hydrogen was based on the weight. As a result, 69.942 g of direct reduced iron was produced with 100 g of iron under 1200 K of temperature and 5 cycles with 7 % of hydrogen.
Humanity has achieved landing on Moon in 1969 and now humanity is looking forward to land on extraterrestrial regions, for example, Mars. To reach the extraterrestrial regions, In-Situ Resource Utilization (ISRU) is regarded as one of the most significant concepts because current technologies could not afford enough propellants and others. Therefore, Moon ISRU is considered one of the most possible keys to reach Mars. In the ISRU, Oxygen is the most essential priority to get from Moon, so the possibility of ISRU with Moon soil is studied in this research using Chemical equilibrium with applications (CEAs) which is developed by the Nasa Glenn research center. The main concept is dissociating Moon soil with E-beam because most major components of Moon soil are composed of Oxygen. Simulation with CEAs is performed, firstly, instead of using E-beam in Moon atmosphere condition. In the program, some of Moon’s atmospheric elements were put in the reaction and Moon’s atmospheric condition was applied. With those conditions, the fraction of Oxygen was simulated by dissociating Moon soil in CEAs. Hence, this research shows the most proper conditions to generate Oxygen and even other ions and atoms. Furthermore, the ultimate goal of this Moon ISRU is shown in this research.
We investigate surface acoustic wave (SAW) sensor for chemical and biological detector as measuring the frequency shift based on adsorption quantities of chemical analyte on SAW propagation path. Important features that define the performance of these sensors are selectivity, sensitivity, stability, response time and dynamic range. In this paper, two inter-digital transducers (IDT) for working frequency of 50MHz, 100 MHz were designed and fabricated using conventional lift-off technique. The shift in SAW velocity due to surface loading leads to a shift in phase, which in turn generates a shift in frequency of the oscillator is confirmed. By different concentration of chemical vapor, the sensitivity of SAW devices will be presented.
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