Exact solutions for unsteady free convection flow over an oscillating plate due to non-coaxial rotation

Background: Non-coaxial rotation has wide applications in engineering devices, e.g. in food processing such as mixer machines and stirrers with a two-axis kneader, in cooling turbine blades, jet engines, pumps and vacuum cleaners, in designing thermal syphon tubes, and in geophysical flows. Therefore, this study aims to investigate unsteady free convection flow of viscous fluid due to non-coaxial rotation and fluid at infinity over an oscillating vertical plate with constant wall temperature. Methods: The governing equations are modelled by a sudden coincidence of the axes of a disk and the fluid at infinity rotating with uniform angular velocity, together with initial and boundary conditions. Some suitable non-dimensional variables are introduced. The Laplace transform method is used to obtain the exact solutions of the corresponding non-dimensional momentum and energy equations with conditions. Solutions of the velocity for cosine and sine oscillations as well as for temperature fields are obtained and displayed graphically for different values of time (t), the Grashof number (Gr), the Prandtl number (Pr), and the phase angle (ωt). Skin friction and the Nusselt number are also evaluated. Results: The exact solutions are obtained and in limiting cases, the present solutions are found to be identical to the published results. Further, the obtained exact solutions also validated by comparing with results obtained by using Gaver–Stehfest algorithm. Conclusion: The interested physical property such as velocity, temperature, skin friction and Nusselt number are affected by the embedded parameters time (t), the Grashof number (Gr), the Prandtl number (Pr), and the phase angle (ωt)

Load-deflection Analysis of CFRP Strengthened RC Slab Using Focused Feed-forward Time Delay Neural Network

In this paper, the load-deflection analysis of the Carbon Fiber Reinforced Polymer (CFRP) strengthened Reinforced Concrete (RC) slab using Focused Feed-forward Time Delay Neural Network (FFTDNN) is investigated. Six reinforced concrete slabs having dimension 1800×400×120 mm with similar steel bar of 2T10 and strengthened using different length and width of CFRP were tested and compared with similar samples without CFRP. The experimental load-deflection results were uploaded, normalized, and converted to a time sequence parameter in MATLAB software. Loading, time, and the effect of the different CFRP strip lengths on the slab moment of inertia were as neurons in input layer and mid-span deflection was as neuron in output layer. The network was generated using feed-forward network and a tapped delay line at the input layer to memorize the input data while training process. From 122 load-deflection data, 111 data utilized for network generation and 11 data for the network testing. The results of model on the testing stage showed that the generated FFTDNN predicted the load-deflection analysis of the slabs in acceptable technique with a correlation of determination of 0.98. The ratio between predicted deflection by FFTDNN and experimental output was in the range of 0.92 to 1.23

Knowledge, Perception and Attitude of Community Pharmacists towards Generic Medicines in Karachi, Pakistan: A Qualitative Insight

Purpose: In an era of escalating healthcare costs and ageing population, there is a need for costeffective measures. This study was aimed to investigate the knowledge, perception and attitude of community pharmacists towards generic medicines. Methods: A  qualitative methodology was adopted. Snowball sampling technique was used to identify eight community pharmacists. Semi-structured interviews were conducted with the pharmacists until the point of saturation was obtained. The interviews, which were audio-taped and transcribed verbatim, were evaluated by thematic content analysis and further verified by other authors’ analyses. Results: Thematic content analysis identified three major themes: knowledge of generic medicines,perception towards generic medicines, and attitude towards generic medicines. All the pharmacist  showed good understanding and positive perception towards generic medicines. Mixed responses were observed regarding dispensing of locally manufactured medicines. Low cost was cited as the major determinant in dispensing locally manufactured generics. Conclusion: The current study showed good knowledge and perception towards generic medicines among community pharmacists in Karachi, Pakistan. It also highlighted mixed attitudes towards generic medicine dispensing. A 24-hour mandatory presence of professionally qualified pharmacists in community pharmacies can boost the confidence of doctors in pharmacists and enhance generic substitution.Keywords:   Community pharmacist, Generic Medicine, Pakistan, Qualitative methodolog

The Simultaneous Impacts of Seasonal Weather and Solar Conditions on PV Panels Electrical Characteristics

Solar energy usage is thriving day by day. These solar panels are installed to absorb solar energy and produce electrical energy. As a result, the efficiency of solar panels depends on different environmental factors, namely, air temperature, dust (aerosols and accumulated dust), and solar incidence, and photovoltaic panel angles. The effects of real conditions factors on power and efficiency of photovoltaic panels are studied in this paper through testing the panel in real environmental tests. To study the mentioned parameters precisely, two panels with different angles are used. The case study is regarding a region of Tehran, Iran, in summer and winter seasons. The results show that panel efficiency during winter is higher than summer due to air temperature decrement. It is discovered that among air pollutants, Al and Fe have the most share in polluting the air that affect the photovoltaic efficiency. Moreover, measuring the accumulated dust on the panels shows more amount in winter in comparison with summer. The important point in studying the effect of tilt angle is that inconformity between solar incidence and photovoltaic panel angles would result in solar radiation absorption and eventually panel efficiency loss and also, photovoltaic panel installation angle would affect the amount of dust deposited on its surface.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Discharge and flow coefficient analysis in internal combustion engine using computational fluid dynamics simulation

Intake system is one of the crucial sub-systems in engine which can inflict significant effect on the air-fuel mixing, combustion, fuel consumption, as well as exhaust gases formation. There are many parameters that will influence engine performances. Good engine breathing is required to get better air flow rate to the engine. One of the methods includes the improvement of intake system by modifying the intake port design. This paper presents the application of Computational Fluid Dynamics analysis on two engines with different intake port shapes. Dimensionless parameters like discharge coefficient and flow coefficient are used to quantify the changes in intake flow at different valve lifts variation. Results show that when valve lift increases, this inflicted the increase in discharge coefficient because of greater mass flow rate of induction air. Both flow and discharge coefficient is dependent on valve lift. Flow analysis proved the relationship by computing the increase of flow coefficient as valve opening increase. The computed analysis shows that different intake port shapes does bring significant effect on discharge coefficient and flow coefficient

Optimal Operation of Solar Powered Electric Vehicle Parking Lots Considering Different Photovoltaic Technologies

The performance of electric vehicles and their abilities to reduce fossil fuel consumption and air pollution on one hand and the use of photovoltaic (PV) panels in energy production, on the other hand, has encouraged parking lot operators (PLO) to participate in the energy market to gain more profit. However, there are several challenges such as different technologies of photovoltaic panels that make the problem complex in terms of installation cost, efficiency, available output power and dependency on environmental temperature. Therefore, the aim of this study is to maximize the PLO’s operational profit under the time of use energy pricing scheme by investigating the effects of different PV panel technologies on energy production and finding the best strategy for optimal operation of PVs and electric vehicle (EV) parking lots which is achieved by means of market and EV owners’ interaction. For the accurate investigation, four different PV panel technologies are considered in different seasons, with significant differences in daylight times, in Helsinki, Finland.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Numerical Computational of Fluid Flow through a Sclera Buckling

In this paper, the implementation of the finite element analysis on the investigation of a phenomenon of fluid flow through a detached retina with sclera buckling treatment is elaborated. To analyze the fluid flow, a paradigm mathematical model is developed. The velocity profile and pressure distribution are simulated. Based on the analysis, it is found that the scale effects which arises from difference in size of the sclera buckling do affects the velocity profile in the human eye. It is important to comprehend the effect of the sclera buckling on the dynamics of the vitreous humour in order to improve the sclera buckling treatment on curing retinal detachment

Hybrid renewable energy power system model based on electrification requirements of one Fathom bank Malaysia

Renewable energy resources are becoming inexorably in the field of generating electrical power due to the fast development of technology, given to its advantages over non-renewable energy resources. Though the source is available in enormous amount, energy produced from single renewable energy resources such as tidal current may fluctuate with the time and the hour of the day or month, depending on the tides. Thus, by having a hybrid power system consisting two or more renewable energy resources coming into play at the same time would be more reliable to support the targeted area. However, the availability of renewable energies depends on the climate change, therefore having a storage battery or backup power is often essential. In this case, the main purpose of this research is to develop an off-grid hybrid tidal current and solar power system along with backup power to support One Fathom Bank Lighthouse in Malaysia with the intention to reduce the dependency on diesel generators. Having the ability to evaluate economic and technical feasibility of power system, HOMER software is used to run simulation and analyze the best combination of components to form a hybrid power system for the lighthouse. The results are based on the best components and sizing in compliance with the load demand and diesel fuel consumption to provide a reliable and cost-effective system

Dynamic Distribution System Reconfiguration Considering Distributed Renewable Energy Sources and Energy Storage Systems

Electric power systems are in state of transition as they attempt to evolve to meet new challenges provided by growing environmental concerns, increases in the penetration of distributed renewable energy sources (DRES) as well as the challenges associated with integrating new technologies to enable smart grids. New techniques to improve the electrical power system, including the distribution system, are thus needed. One such technique is dynamic distribution system reconfiguration (DNSR), which involves altering the network topology during operation, providing significant benefits regarding the increased integration of DRES. This paper lays out an improved model which aimed to optimize the system operation in a coordinated way, where DRES, energy storage systems (ESS) and DNSR are considered as well as the uncertainty of these resources. The objective function was modeled to incentivize the uptake of DRES by considering the cost of emissions to incentivize the decarbonization of the power system. Also, the switching costs were modeled to consider not only the switching, but also the cost of degradation of these mechanisms in the system operation. Two systems are used to validate the model, the IEEE 119-bus system, and a real system in São Miguel Island. The results of this paper show that using DNSR, DRES, and ESS can lead to a significant 59% reduction in energy demand through a 24-hour period. In addition, using these technologies results in a healthier, more efficient, and higher quality system. This shows the benefits of using a variety of smart grid technologies in a coordinated manner.© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

Single channel magnetic induction spectroscopy technique for fetal acidosis detection

Current fetal acidosis diagnosis needs an invasive measurement which required a doctor to puncture fetal scalp to acquire blood pH. This method introduced risk to the fetal which fetal scalp may bruise and infected. This paper discusses a noninvasive method employing a single channel magnetic induction spectroscopy technique as an alternative method to diagnose acidosis in fetal without puncturing the fetal scalp. The studies are based on numerical simulation models to investigate the most feasible sensor coil that is sensitive and effective to be implemented in hardware setup as the shape of coil influences directly the sensing performance of the magnetic induction spectroscopy system. The study has found that the circular coil is more sensitive than linear coil. The system tested with different pH samples to mimic the blood pH value. The result is very promising with good correlation approaching 1 has been achieved. Therefore, magnetic induction spectroscopy technique has good opportunity to be applied as an alternative method to detect acidosis in the fetal with circular coil is performed as the best sensing coils for MIS hardware