Search results

This study aims to find a new alternate source for biodiesel conversion. The alternate source must be easily available, and it should give more oil yield than available edible, inedible sources. To meet the fuel demand in the transportation sector with edible oil-based biodiesel causes food versus fuel crisis. In addition to this, it increases NO_x and CO₂ in the environment.

The present paper reviews the comparison of algae oil yield, fatty acid composition and its biodiesel properties’ effect on diesel engine characteristics.

Algae were the only source to fulfil fuel demand because its oil and biodiesel yield is higher than other sources. Algae can grow by capturing carbon dioxide from the environment, and its fatty acid composition is more suitable to run diesel engines.

There is an improvement in engine performance–emission tradeoff with algal biodiesel.

Solar energy varies with time, intermittent; an accumulator unit is required to attach with collectors to collect energy for use when the sunshine is not available. This paper aims to design a system for storing the solar sensible heat thermal energy.

This paper presents the design and experimental evaluation of sensible heat thermal energy storage (TES) system for its energy storage performance by varying the air flow rate and packing material shape. Heat transfer fluid as air and solid concrete material of high density of different shapes were used for storage.

This paper presents the evaluation of data of number of experimental observations on the system. It was found that charging/discharging was based on the shape of the material and void fraction.

This paper provides the data for designing the TES, considering the concrete as storage material and shape of material for optimizing the system.

The purpose of this study is to get much insight about the combustion and emission characteristics of partially processed high free fatty acid linseed oil, i.e. esterified linseed oil (ELO), and diesel fuel in a single-cylinder compression ignition engine.

The variable compression ratio (CR) diesel engine (3.5 kW) of CR ranging from 12:1 to 18:1 is used for the experimentation purpose. In this study, CR varied from 16:1 to 18:1 for investigating the combustion and emissions characteristics of ELO. Various features such as combustion pressure, net heat release rate and mean gas temperature are analysed. The emission characteristics such as hydrocarbon, carbon monoxide, carbon dioxide and nitrogen dioxide are investigated with different loads and CRs. The effect of an ambient temperature condition is also reported.

Results from this investigation reveal that the burning of ELO is found to be advanced for all CRs as compared to diesel fuel, whereas these features were found to be lower for a CR of 17. Emissions of ELO are found to be higher at all loads and CRs. Overall, this study provides a necessary framework to enhance further research in this area.

This investigation shows that ELO has better combustion in the first phase of combustion. However, the exhaust emissions of ELO have higher value due to improper combustion in the second and subsequent phase of combustion due to higher viscosity.

The aim of this study is to identify key factors limiting efficiency of pumped heat energy storage systems and determine some general features of transient behavior of solid state, sensible heat storages. Moreover, it aimed at establishing a feasible approach to transient conjugate heat transfer (CHT) analyses for such applications.

A zero-dimensional analytical model is used to determine the system efficiency sensitivity to efficiency of its components. Analysis of argon gas flow in an exemplary configuration of layered bed thermal energy storage is presented. The analysis incorporates a unsteady reynolds averaged navier stokes model with conjugate heat transfer between gas and solid storage core.

It is established that exergetic efficiency of the heat storage is one of the key factors for the system’s overall performance. Three full cycles of storage charging and discharging having 17 h physical time in total are simulated, with calculation of exergetic efficiency for each of the cycles. From standpoint of the system efficiency, it is concluded that the presented heat storage kind has limited exergetic efficiency because of severe temperature drop at the solid–fluid interface in comparison to granular kind of heat storage devices. From the methodological standpoint, it is concluded that calculating the exergetic efficiency of the heat storage by direct computational fluid dynamics (CFD) analysis requires significant amount of walltime and computational resources.

The paper presents unconventional approach to using standard CFD tools by exploiting numerical diffusion to numerically suppress high-frequency solution oscillations. This strategy grants that the analysis, otherwise requiring impractically long computation walltime, is completed within a practical time.

This paper aimed to assess the service quality of the main seaports in Oman, which were Sohar, Ad Duqm and Salalah. The aim was to come up with ways to enhance the port service quality (PSQ) in Oman so that it could align with the Sultanate of Oman Logistics Strategy (SOLS) 2040 goals and achieve excellent and efficient operations.

To evaluate the service quality level of the port operators, this paper used a descriptive research design with Resources, Outcome, Process, Management, Image/reputation and Social (ROPMIS) modelling.

The findings indicated that the overall PSQ rating was currently between “satisfactory” and “very satisfactory” levels. However, the study also found that by empowering resources, outcomes, processes, management, image and social responsibility aspects, the port operators could provide a “high” quality of service, making their seaport operations more effective and efficient.

The study offers recommendations for improving port services in Oman, including investment in modern seaports, upgrading infrastructure and facilities, ensuring safety and efficiency of cargo operations, meeting and exceeding customer expectations, adopting new technology and automation, hiring policies that attract diverse talents, implementing environmentally friendly practices and improving governance. Overall, this study contributes to the literature and managerial practices in PSQ aspects and its contribution to the SOLS 2040 in Oman.

The originality and novelty of this study lie in its comprehensive assessment of the service quality of Oman's ports and the identification of areas for improvement to achieve outstanding service levels.

Vast areas have been studied toward combustion and emission analysis in vegetable oil methyl esters and quite a few in algal oil biodiesel. To analyze the better alternate source for diesel engine, this study aims to investigate the combustion behavior and emission characteristics between cottonseed biodiesel and algal oil biodiesel on comparison with mineral diesel in a compression ignition engine.

The fuel properties like density, kinematic viscosity, calorific value and Cetane number have met the biodiesel standards for both algal and cottonseed biodiesel. At rated power, engine was operated on all three test fuels, where combustion analysis describing in-cylinder pressure, peak pressure, rate of pressure rise and rate of heat release and emission characteristics including hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NOx) and smoke for both biodiesel comparing mineral diesel.

Algal and cottonseed biodiesel showed up to 2-3°CA delayed start of combustion comparing mineral diesel curve. The in-cylinder pressure of algal biodiesel was found to be 68 bar, whereas cottonseed biodiesel exhibited 65 bar at full load condition. Similarly, the rate of pressure rise and rate of heat release of algal biodiesel depicted 7.9 and 10.7 per cent rise than cottonseed biodiesel, respectively. As the load increased, ignition delay showed decreasing trend, while combustion duration showed an increasing trend. HC, CO and smoke emissions were seen to be lower than mineral diesel with noticeable increase in NOx emission.

In this present investigation, biodiesel from Stoechospermum Marginatum, a marine marco algae, was used to fuel the compression ignition engine. Its combustion behavior and emission characteristics are compared with cottonseed biodiesel, a vegetable oil-based biodiesel having similar physio-chemical characteristics to understand the suitability of algal biodiesel in compression ignition engine. This study involves the assessment of straight biodiesel from macro algae and cottonseed oil on standard operating conditions.

The purpose of this study is to present a comprehensive review of the fundamental concepts and terminologies pertaining to different types of aluminium metal matrix composites, their joining techniques and challenges, friction stir welding (FSW) process, post-welding characterizations and basic control theory of FSW, followed by the discussions on the research reports in these areas.

Joining of aluminium metal matrix composites (Al-MMC) poses many challenges. These materials have their demanding applications in versatile domains, and hence it is essential to understand their weldability and material characteristics. FSW is a feasible choice for joining of Al-MMC over the fusion welding because of the formation of narrow heat affected zone and minimizing the formation of intermetallic compounds at weld interface. The goal in FSW is to generate enough thermal energy by friction between the workpiece and rotating tool. Heat energy is generated by mechanical interaction because of the difference in velocity between the workpiece and rotating tool. In the present work, a detailed survey is done on the above topics and an organised conceptual context is presented. A complete discussion on significance of FSW process parameters, control schemes, parameter optimization and weld quality monitoring are presented, along with the analysis on relation between the interdependent parameters.

Results from the study present the research gaps in the FSW studies for joining of the aluminium-based metal matrix composites, and they highlight further scope of studies pertaining to this domain.

It is observed that the survey done on FSW of Al-MMCs and their control theory give an insight into the fundamental concepts pertaining to this research area to enhance interdisciplinary technology exploration.