Mechanization and Import Substitution in Zimbabwean Farmers' Equipment: A Case Study of the Revitalization of an Abandoned Tractor Trailer
Drill String Vibrational Analysis and Parametric Optimization for a Portable Water Well Rig Development
An Efficient Deep Neural Network with Amplifying Sine Unit for Nonlinear Oscillatory Systems
The Occupational Directness of Nanorobots in Medical Surgeries
Recent Trends in Solar Thermal Cooling Technologies
A Review on Mechanical and Tribological Characteristics of Hybrid Composites
Design of Oil-Ammonia Separator for Refrigeration Systems
Design and Experimental Investigation of a Natural Draft Improved Biomass Cookstove
Progressive Development of Various Production and Refining Process of Biodiesel
Optimization of Wire-ED Turning Process Parameters by Taguchi-Grey Relational Analysis
Evaluation Of Mechanical Behavior Of Al-Alloy/SiC Metal Matrix Composites With Respect To Their Constituents Using Taguchi Techniques
Multistage Extractive Desulfurization of Liquid Fuel by Ionic Liquids
Isomorphism Identification of Compound Kinematic Chain and Their Mechanism
Development of Electroplating Setup for Plating Abs Plastics
A Comprehensive Review of Biodiesel Application in IDI Engines with Property Improving Additives
Abandonment of equipment on Zimbabwean A1 and A2 farms has significant costs for both farmers and the national economy, as farmers often continue using outdated or traditional farming methods. Maintenance practices, innovation, research, design, and modern machinery have evolved considerably over the past hundred years, shifting from old maintenance applications to planned maintenance strategies combined with Import Substitution Industrialization (ISI). For Zimbabwean farmers, adopting this approach is crucial, particularly for revitalizing farm implements and machinery. Currently, it is evident that many farm implements and equipment have been abandoned. These implements and equipment could be assessed and mechanically restored to their operational state. A mechanical assessment of abandoned equipment was conducted, focusing on main components such as the chassis and suspension to facilitate the revitalization process. This was followed by a product development plan outlined in the methodology. The abandoned trailer was dismantled, with selected components purchased locally, and then reassembled using mechanical methods. The mechanical activities involved included cutting with grinders, joining through arc welding, and using bolts and nuts. As a developing country striving to adopt modern technologies, Zimbabwe's application of Import Substitution Industrialization is a crucial strategy for embracing sustainable development. Farmers are advised to integrate basic welding knowledge into their farming activities and acquire essential machinery, such as CO2 welding machines and workbenches, for their mechanical workshops. Large-scale farmers in Zimbabwe typically have workshops equipped with these basic machining tools. The abandoned trailer was reconditioned to a functional state using basic machining methods and tools, as detailed in this paper.
The vibration of a drill string is a key topic of study in drilling and mining engineering. Excessive Drill String (DS) vibrations can lead to early failure of bits due to fatigue, Drill Pipe (DP) fractures, bearing damage, and a decrease in the Rate of Penetration (ROP). This occurs when the drill string rotates at its natural frequency, which is known as resonance. A modal and harmonic vibrational analysis of a drill string up to 60-65 meters long was conducted in a vertical water well through parametric studies. This project investigates the vibration of a drill string under various parameters, including drill string lengths, Weight on Bit (WOB), and drill string rotational speeds. The Rotational Speed (RS) in the drill string induces lateral vibrations and stick-slip in torsional vibrations. Finite element modeling of the drill string was performed using ANSYS Workbench (Mechanical). Modal and harmonic frequencies were determined to obtain the optimal drill string length and rotational speeds, using Campbell diagrams and varying weights on bits. Different weights on the bit were assumed to simulate the drilling environment. One of the modern methods used to simulate dynamic behavior in drilling operations is random vibrational analysis. A random vibrational analysis of the drill string was performed in a vertical water well using ANSYS Workbench 2020. This analysis aimed to identify the frequency response of the drill string, with the probability of deformation for each sigma under random vibration being evaluated. The analysis indicated a higher probability approximately 99.7% of failure along the axis of the supplied PSD acceleration. The response power spectral density (RPSD) was analyzed in the x, y, and z directions, focusing on any point in the bottom hole assembly, primarily the bit. The response PSD results indicated that as the Drill Pipe (DP) increased, resonance spikes rose across all axes, leading to lateral and longitudinal vibrations in the drill string. These findings highlight lateral movement as a primary cause of vibration, offering insights for optimizing drilling parameters.
Nonlinear differential equations play a pivotal role in modeling various physical phenomena, capturing their oscillatory behaviors. Numerous analytic and numerical methods have been developed to obtain precise or approximate solutions for nonlinear dynamics. This study introduces a novel approach utilizing neural network strategies, known for their computational flexibility. This study proposed a novel architecture for deep neural networks that is intended to simulate the nonlinear oscillations of two systems. It has been modified to include an oscillatory activation function called the amplifying sine unit. This study compares the results from our customized neural networks with those from the conventional stable and reliable numerical technique of the Runge-Kutta method of order four. Remarkably, there is striking agreement between the outcomes of the two methods, highlighting the ability of deep neural networks to identify nonlinear dynamical behaviors without requiring explicit conversion of mathematical models into an equation system.
The incorporation of nanotechnology into the field of medicine is on the brink of bringing about a significant transformation in surgical procedures. Notable advancements in surgical nanorobots hold the promise of delivering improved levels of precision and functionality. In this comprehensive examination, we delve into recent progress and future trajectories in the domain of surgical nanorobots, with particular emphasis on advancements seen in biological and diamondoid-based nanorobots, computational nanomechatronics, and various techniques employed in nanomanufacturing. This discourse highlights key areas such as the evolutionary journey of nanorobots towards more intricate designs, the incorporation of intelligent materials into their structure, and the strides being made in the development of sophisticated targeting and navigation systems. Furthermore, the discussion extends to exploring the potential applications of nanorobots in minimally invasive surgeries and tele-operated procedures, emphasizing their crucial roles in tasks such as controlled drug release, actuation and mobility mechanisms, and the integration of cutting- edge sensing technologies. Novel approaches, including self-assembly processes, swarm robotics strategies, and the utilization of energy harvesting mechanisms, are thoroughly analyzed, highlighting their pivotal roles in enhancing the efficacy and autonomy of these miniature devices. Moreover, the narrative also addresses the various challenges that lie ahead and potential future pathways in materials engineering, targeting methodologies, diagnostic tools, and the seamless integration of nanorobots with the existing landscape of medical technologies. It is evident that, with the continuous stream of advancements being made, surgical nanorobots are poised to bring about a paradigm shift in patient care, ushering in unparalleled levels of precision and therapeutic capabilities.
The issue of the impact of global warming and climate change is at an alarming stage, along with the increasing demand for air conditioning and refrigeration in warm weather regions. The use of integrated renewable energy technologies, such as solar thermal technology for cooling and refrigeration, has proven to be a key solution for overcoming problems associated with conventional resources. Solar cooling technologies do not impose negative environmental impacts and can alleviate the burden on electric utilities. Numerous studies on solar-assisted cooling systems are underway to achieve reductions in cost, improvements in performance, and greater compactness compared to conventional systems. This paper presents a review of various available solar cooling methods and technologies, detailing their working principles, Coefficients of Performance (COP), types of collectors, working pairs, and their advantages and disadvantages based on previous literature. The focus is primarily on solar thermal and solar electrical technologies, highlighting their different attributes and providing essential knowledge for selecting appropriate solar cooling technology for specific applications. Additionally, several references, including experimental and simulation investigations, are summarized.
