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An Investigation on the Utilization of R470A for Air-Conditioning Systems Towards 2025
Get PDFThe refrigerants with GWP > 750 will not be used in air conditioners according to the application of European Union restrictions that will become valid as of 2025. In this context, this study aims to investigate theoretically the utilization of the non-flammable and low-GWP refrigerant of R470A in the air conditioning system. In the analysis, R470A and R32 are compared for the evaporation temperatures of 5, 10, and 12°C while the condenser temperatures of 40 and 50°C. Although the COP of R470A is determined to be lower than R32 for a given situation of evaporation and condenser temperature, it can be safely used in systems requiring a higher amount of refrigerant charge due to its non-flammable property
Prediction of Petrophysical Properties using Post Stack Seismic Inversion and Geostatistical Techniques over F-3 Block, Netherlands - A Comparative Study
Get PDFTo estimate petrophysical parameters, seismic inversion techniques have been frequently used for estimating attributes like P-impedance, elastic impedance, S-impedance, density, Vp / Vs ratio, and gamma-ray logs from seismic and well-log data. These characteristics enable us to comprehend subsurface lithology for geo-seismic analysis, including its extent and shape. Four different post-stack inversion techniques, including bandlimited inversion (BLI), colored inversion (CI), maximum likelihood sparse spike inversion (MLSSI), and model-based inversion (MBI), have been applied to the post-stack seismic data from the F3 block in the Netherlands in this study. The objective is to compare the efficacy of these inversion methods over F3 block seismic data. For post-stack inversion, the data was inverted into a very high-resolution P-impedance volume. The analysis depicts that all four inversion methods provide mutually consistent subsurface information with marginally better MBI results. Furthermore, geostatistical techniques have been used intensively for further testifying the results obtained from post-stack inversion methods. The geostatistical techniques use seismic data-derived attributes and inverted impedance-derived attributes as input to estimate P-wave velocity, porosity, and density away from the boreholes. Two geostatistical methods namely probabilistic neural network (PNN) and multilayer feed-forward neural network (MLFN) are used for the analysis. Porosity, density, and P-wave velocity have been predicted using both techniques which highlighted different characteristics of the subsurface with very detailed information. The derived results show that reservoir properties have been better estimated with the combination of MBI and PNN techniques for F3 block data over the other methods used in this study.
On the G'/G Expansion Method Applied to (2+1)-Dimensional Asymmetric-Nizhnik-Novikov-Veselov Equation
Get PDFIn this paper, the G'/G expansion method is applied to the (2+1)-dimensional Asymmetric-Nizhnik-Novikov-Veselov equation (ANNV). The motivation is creating new families of solitary waves. The system of equations has been combined in one partial differential equation (PDE) and the traveling wave variable has been applied to transform the resultant equation into an ordinary differential equation (ODE). The homogenous balance condition has been applied to determine the truncation variable of the G'/G expansion. Four cases are created according to the appropriate choice of the arbitrary constants relations. For each case, some new solitary wave solutions including solitons and kinks represented by trigonometric, hyperbolic, logarithmic, polynomial, and combinations of these functions
Investigating the Effect of Static Magnetic Field and Magnetic Iron Oxide Nanoparticle on Enzymatic Antioxidant Defense in Dracocephalum polychaetum Cell Suspension Culture
Get PDFThis study was conducted to investigate the effect of magnetic iron oxide nanoparticles (MNP) and static magnetic field (SMF) on the activity of antioxidant enzymes in the cell suspension culture of Dracocephalum polychaetum (Lamiaceae family). The treatment procedure was done by cultivating the cells either with 100 ppm MNP, SMFs, or simultaneous exposure to both MNP and SMFs. The SMF at 30 mT was uniformly applied to the cells either for 3 or 4 days with 3 hours per day or 5 hours per day intervals, respectively. The highest activity of polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), catalase (CAT), malondialdehyde (MDA) content, and electrical conductivity (EC) were observed under the elicitation of the cells with simultaneous exposure to both MNP and SMFs, but the highest amount of FRAP value was observed under the elicitation of the sample with the MNP treatment. Also, the results of this study showed that the greatest activity of peroxidase (POX) was observed under SMF and MNP treatments. In general, SMF and MNP treatments caused various changes in cell structure and metabolism by inducing oxidative stress and having a direct effect on the membrane. The cell activated its enzymatic antioxidant defense system in response to these treatments, which caused changes in its activity and amount compared to the control cell
A Method for Evaluation of Streetscapes: Relationship between Visual Entropy and Interesting Streetscape
Get PDFThe present research studies the complexity of urban facades, which is related to the visual diversity and correlation of the components of urban facades. It studies how the complexity of urban facades affects their desirability amongst citizens and what their preferences are when it comes to facade complexity. In addition, it addresses the complexity of urban facades in both quantitative and qualitative forms and investigates the relationship between quantitative and qualitative data and the desirability of using the correlation analysis method in urban facades.
To obtain quantitative data, a survey was conducted on Nowshahr citizens, and the data was analyzed through MATLAB software. The data obtained is the image entropy, which indicates the number of image irregularities. The results indicated that the Nowshahr citizens prefer the second complexity level, then the first complexity level, followed by the third complexity level, and finally the fourth complexity level, respectively.
There is a slight correlation in the results of the quantitative-qualitative data comparison. Therefore, using entropy as a measure of complexity cannot be confirmed in this study, and further research is needed
Assessing Progress in Reducing the Number of Disaster-affected People: Insights from Zimbabwe
Get PDFIn 2015, 187 countries appended their signatures to the Sendai Framework for Disaster Risk Reduction. This framework has seven global targets which need to be monitored both at national and global levels. In order to promote the monitoring and reporting on progress in attaining the global targets, the United Nations Office for Disaster Risk Reduction provided some technical guidance notes and methodologies. Using the case study of Zimbabwe, this study used the technical guidance notes and methodologies to assess the country’s progress in reducing the number of people affected by disasters. Quantitative data for this assessment came from public sources published by the Government of Zimbabwe spanning the period 1990 to 2019. This data was analysed using 3-year and 5-year moving averages. In addition, the study used qualitative interviews to explain the trends in the number of people affected by disasters. Results showed slight decreases in the number of people affected by both aggregated and disaggregated disasters. Drought disasters emerged as the only one that affected millions of people yearly. However, storms and epidemics were sporadic and characterised by big spikes. The study concluded that Zimbabwe is slowly attaining Target B. The study further offered three policy implications that are meant to significantly reduce the number of people affected by disasters. This includes the need to strengthen drought preparedness/mitigation, and disease surveillance and control systems
Decoding Electrocatalysis: Transforming Aluminum-Clad TLC Plates into Potash Alum for Hydrogen Evolution Exploration
Get PDFThis work deals with using a waste aluminum-based TLC plate to prepare crystalline potash alum, which is subsequently activated for the study of hydrogen evolution reaction in alkaline KOH. The structural and morphological characterization of the synthesized potash alum (PA) has been assessed with powder X-ray diffraction and thermogravimetry analysis. Scanning electron micrographs reveal the morphology of the activated potash alum. The heterogeneous electrocatalytic HER activity in 1 M KOH attributes a moderate electrocatalytic efficiency for activated potash alum (APA) in the light of onset potentials, Faradic efficiency, double-layer capacitance, electrochemically activated surface area, and number of active sites. However, the electrocatalyst APA is a pre-catalyst as it undergoes a significant structural transformation under the electrochemical operation, leading to Al2O3 nanoparticles being the active catalyst for hydrogen production. Possibly, the chemical inertness of the Al2O3 induces a limitation in the local vicinity for the synergistic effect for facile electron transport in alkaline KOH
Challenges and Way Forward to Maintain Air Quality Standard in Urban Areas
Get PDFThis thesis explores the intricate relationship between urban air pollution, economic growth, population dynamics, and energy consumption. Addressing impacts on climate change, biodiversity, agriculture, and human health, it emphasizes compromised urban air quality due to pollution sources such as power generation, vehicle traffic, and construction. Key pollutants like particulate matter, carbon dioxide, sulfur dioxide, and nitrogen dioxide pose significant health risks. The study identifies road transportation as a primary contributor, underlining alarming statistics from WHO on global air quality, particularly impacting low-level socio-economic regions. Legislations and policies dating back over a century form the foundation for global air pollution control efforts. The research highlights innovative solutions like urban green spaces, smart traffic management, and renewable energy investments. It stresses the importance of public transportation, electric vehicles, clean construction practices, and initiatives to reduce industrial emissions. In response to challenges, the thesis proposes a comprehensive mitigation plan covering strategy such as promoting public transport, energy conservation, recycling, and afforestation. It outlines a way forward, emphasizing integrated urban planning, public awareness campaigns, government policies, and international collaboration. In conclusion, the thesis calls for collective responsibility to address urban air pollution's adverse effects on public health and the environment. The proposed roadmap aims to create sustainable, resilient, and healthier urban environments through a holistic and collaborative approach
Biomagnetic Fluid Flow on a Nonlinearly Stretching Sheet with Variable Thickness in a Magnetic Environment
Get PDFThe main contribution of the current work is a numerical and mathematical investigation of the effects of magnetic dipole and electrical conductivity on the heat and flow transfer of biomagnetic fluid over a non-linear stretched sheet with variable thickness. Static magnetic fields are produced by magnetic dipoles, which are used in medical a pplications such as MRI, drug administration, and cancer therapy. Additionally, the impact of non-linear heat source/sink features was examined in the study, leading to an interesting phenomenon. The PDEs are attenuated to nonlinear ODEs with dealing appropriate similarity variables. These resultant ODEs are computed by developing an effective method emerged on the application of the finite differences technique. In the end, this section offers a summary of the implications resulting from different physical limitations on blood flow, including variable thickness and power index effects. It was discovered that the rise in Kelvin and Lorentz forces in the boundary layer significantly affected blood flow. The current findings for the biomagnetic fluid model are novel and inventive since they effectively expand upon the issues previously addressed by previously published scientific documentation
Thermal Effects of Alternative Environmentally Friendly Material Instead of Silicone in Battery Modules
Get PDFNowadays, the demand for electric vehicles is increasing rapidly. One of the most important components of electric vehicles is the battery pack. The reduction of their carbon footprint and recyclability is getting more important. For that reason, the usage of environmentally friendly materials or production methods in their production should be studied. This paper aims to investigate an alternative material for silicone which is used to avoid vibration of the battery cells inside of the battery module. Synthesized Hydrogel, which is not hazardous to the environment, is suggested instead of silicone. Besides its environmentally friendly property, Hydrogel does not use any other curing process like silicone and thus reduces the curing process time and energy that is spent for the application of the silicone which is 100 oC and 5 hours. The heat generation of the battery cells inside of the battery module is also numerically analyzed with electrochemical thermal modeling and the comparison of the silicone and suggested Hydrogel material instead of silicone is performed. The results showed that Hydrogel can be used instead of silicone and this material can remove the curing process during the production of the module and can reduce the carbon footprint of the battery module