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The purpose of this study is to numerically analyze the thermal and entropy generation characteristics on two-dimensional, incompressible, laminar single-phase flow of Al₂O₃-water nanofluid in a micro-channel subjected to asymmetric sinusoidal wall heating with varying amplitude, length of fluctuation period and phase difference of applied heat flux for Reynolds number in the range of 25-1000.

The numerical computation is based on the Finite Element Method and the Lagrange finite element technique is used for approximating the flow variables within the computational domain.

The average Nusselt number increases with increasing Reynolds number (Re) for all the volume fractions of nanofluid. However, the total entropy generation decreases up to a critical value of Re and increases thereafter. Increase in volume fraction shifts the critical Re towards the lower Re regime. The average Nusselt number and total entropy generation increase with amplitude and length of fluctuation period of heat flux. The optimal choice of volume fraction for lesser entropy generation and higher heat transfer is found to be 3 per cent independent of the value of amplitude, length of fluctuation period and phase difference of the heat flux.

To the best of authors’ knowledge, the interplay of various parameters concerning non-uniform heating in achieving the maximum heat transfer with minimum irreversibility has not been investigated. Focusing on this agenda, the results of this study would benefit the industrial sector in achieving the maximum heat transfer at the cost of minimum irreversibilities with an optimal choice of inlet Reynolds number, volume fraction of nanofluid, amplitude, length of the period of fluctuation of heat flux and phase difference of applied heat flux.

The purpose of this paper is to optimally operate a Smart Microgrid which is interconnected to the main grid so as to minimize expenditures associated with CO₂ emissions. Microgrids could come into play to aid the network through CO₂ emission reduction while increasing their efficiency through local generation. For this purpose, a Smart Microgrid incorporating Distributed Energy Resources (DER), especially Renewable Energy Sources (RES), is operated optimally while keeping the CO₂ emissions in check in order to minimize the financial burden from emissions stemming from the carbon tax. Since the network is assumed to be interconnected with the main grid, there is a consideration of the expected emissions associated with the imported energy.

An economic/environmental dispatch problem is mathematically formulated using an objective function and the constraints that it is subject to. The methodology is applied on a typical 17-bus test distribution network, representing a Hellenic LV network. Various carbon tax rates and their impact on the system marginal price are examined, in terms of their effect on distributed generation (DG) and as a second step, the effect of imposing lower carbon tax rates for micro-sources with the goal of benefitting from their more eco-friendly generation capabilities. In order to assess that benefit, hourly grid emissions coefficients are derived based on actual grid data.

The CO₂ tax refund policy towards the DG owners can lead to optimal coverage of consumers, optimal financial result both for the DG owners and the operator and greater DG integration within the smart grid.

Greater DG integration within the smart grid by using a CO₂ tax refund policy.

The purpose of this paper is to present a methodology to quantify the solar energy potential for applying photovoltaic systems and find an efficient geometry for urban blocks to obtain a better quality of daylighting in terms of continuous daylight autonomy (DA) and spatial DA with less energy consumption.

The paper is based on a complete simulation of the topography and micro-climate of the area under study. Simulations were performed using ArcGIS and Rhinoceros and urban daylight (UD) and urban modeling interface plugin for a neighborhood in the region of Narmak in Tehran, Iran. Five configurations of a neighborhood were compared using simulations.

It was found that the impact of the geometrical form on daylight gain and energy consumption is significant and the terraced model is the most suitable form for obtaining a constant floor area ratio. Furthermore, it is an optimal form of urban blocks to gain the most energy through photovoltaic systems in the neighborhood as it would be able to satisfy about 42 percent of the energy needs.

Planning to achieve sufficient energy factors in cities is a difficult task, since urban planners often do not have adequate technical knowledge to measure the contribution of solar energy in urban plans and this paper aims to introduce a comprehensive modeling methodology by which the urban energy planning can be used and understood in the urban context to make it completely clear as a strategy of implementation.

The purpose of this paper is to establish a methodological framework to address key issues in electricity distribution network development. The paper defines subtasks in the strategy process and presents key elements in the strategy work and long‐term network planning. The results are illustrated by a case network.

The paper describes the methodology for cost and reliability analyses in the strategy work. The focus is on techno‐economic feasibility of certain network development technologies in the network strategy and the surveys are linked to economic regulation, specifically to reliability of supply and allowed return. The study addresses the stages of strategic decision making and compilation of investment strategies.

The strategic planning concept and methods are applicable in practice; the results have proven valuable in the long‐term business development and in discussions with the company owners. Outage costs are an essential element in the economic regulation of the business, reliability being a key driver in network planning.

There is no universal solution to strategic decision making, but each development task is highly case specific. This is due to diverging operating environments and targets set by the company owners; these issues strongly influence the strategy process.

The work illustrates strategic planning in an actual distribution company and shows how the methodology can be applied to the strategic network development. Nevertheless, the results cannot be generalised as such, but each network has to be considered individually.

The proposed concept can be applied to the long‐term development of distribution networks. The results are internationally applicable, yet diverging regulatory models call for specific methodology in each country.

The purpose of this paper is to investigate “best practice” building strategies and sustainability‐oriented techniques and tools used to assess the energy performance of housing developments. The objective is to propose guidelines that can integrate futures thinking into the selection of energy‐related design responses, such as materials, building components and energy systems, from the early project stages.

An interdisciplinary approach is adopted with the inclusion of social, economic and environmental aspects of the energy supply and demand. A multiple case study approach is employed, which focuses on the residential sector of European mixed‐use developments that represent sustainable communities of “best practice”.

The investigation of “best practice” housing developments reveals that the majority of design responses cover mainstream environmental design strategies. Energy efficiency measures are still the “low hanging fruit” towards meeting the sustainability objectives. In addition, established sustainability‐oriented techniques and tools used focus mostly on projections of almost certain facts rather than explorations of a portfolio of plausible futures.

The paper represents a shift away from the short‐term mindset that still dominates design and construction practices. It provides an overview of building strategies and decision‐support techniques and tools for improving and incentivising sustainable energy solutions over the long term.

The purpose of this paper is to further extend the work of Weng and Chen (2009) by considering heat generation/absorption nature of fluid.

Exact solution of momentum equation is derived separately in terms of Bessel’s function of first and second kind for heat-generating fluid and modified Bessel’s function of first and second kind for heat absorbing fluid.

During the course of numerical computations, it is found that skin friction and rate of heat transfer at outer surface of inner cylinder and inner surface of outer cylinder increases with the increase in heat generation parameter while the reverse trend is found in the case of heat absorption parameter.

In view of the amount of works done on natural convection with internal heat generation/absorption, it becomes interesting to investigate the effect of this important activity on natural convection flow in a vertical annular micro-channel. The purpose of this paper is to further extend the work of Weng and Chen (2009) by considering heat generation/absorption nature of fluid.

In the industry, there is always a demand to shorten the task completion durations to maximize the efficiency of the operation. This work focuses on making use of a special type of kinematic redundancy, macro–micro manipulation, to minimize the task completion duration. The purpose of this paper is to develop the most convenient trajectory planner to be integrated with industrial computerized numerical control (CNC) systems to resolve kinematic redundancy for task duration minimization.

A special type of kinematic redundancy is devised by using two kinematically different mechanisms that have different advantages, which are named as macro and micro mechanisms. In this case, the control design including the trajectory planning should be devised taking into account the distinct advantages of both mechanisms. A new trajectory planning algorithm is designed and used for the constructed planar laser-cutting machine, and some benchmark pieces are cut.

Offline method has practical limitations for employment in a real case scenario such as assuming infinite jerk limits for each axis motion. This limitation was removed by using an online trajectory generation technique. Experimental test results indicate that the online trajectory planning technique developed for the macro–micro mechanism to shorten the task duration was successful.

Although the new trajectory planning algorithm is implemented for a laser-cutting machine, it can also be used for other manufacturing systems that require higher acceleration and accuracy levels than the conventional machines. The new algorithm is compatible with the commercially available CNC systems.

In this work, a new approach to reducing the task duration for planar machining operations was introduced by making use of macro–micro manipulation concept. The core novelty of the work is devising trajectory planning algorithms to get the most efficiency in terms of acceleration limits from a macro–micro manipulation while making these algorithms deployable to most of the CNC systems.

Examples are given for the technical applicability of a novel development of selective laser sintering called “laser micro sintering”.

Together with a specific method to produce powder layers, the controlled application of pulsed radiation for the processing of sub‐μm grained metal powders was exploited to produce micro‐tools with a heretofore unattained structural resolution.

High resolution micro bodies are displayed. Instruments could be generated which proved to fulfil their designation as grip bits for micro manipulators. The micro‐bodies can be generated detachably from or firmly fixed to the construction substrate. The material of the generated bodies withstands the traction forces when used as an injection mold for polymer casts.

Densities and structural resolutions can still be improved especially with a newly updated version of the equipment. Laser micro sintering of materials, other than metal (e.g. ceramics), has still to be developed. The introduction of the equipment and the technique into the market is on its way.

Micro‐tools can be generated with an overall structural resolution of 30 μm and with all the advantages of a freedom technique.

The paper informs the technical community on a new novel modification of the freeform technique selective laser sintering, demonstrating the solution of some problems that have hampered the progress of metal laser into resolution ranges below 100 μm. It also supplies evidence for the technical applicability.

The purpose of this paper is to present an original design procedure for a flight control system.

An optimization process, based on a genetic algorithm (GA), is used to meet the frequency domain handling qualities requirements in the longitudinal plane for an unconventional platform characterized by nonlinear aerodynamics. The parameters are implemented in the search process as fitness functions related to the expected magnitude of bandwidth and delay for an existing micro aerial vehicle. The bandwidth and the delay of the longitudinal short‐term attitude response are estimated before and after the inclusion of the flight control system in the simulation model, and the parameters are compared with the expected handling qualities levels. A qualitative analysis of handling qualities levels is also performed by implementing the augmented aircraft in a simulator with a realistic visual environment.

The results show that an optimal search process based on a GA can implement the handling qualities requirements with a computational procedure that is straightforward.

Even if the requisites for bandwidth and delay implemented in the search process are general in use as no specific aircraft response type is taken as a reference for the estimation of handling qualities requirements, only future experimental work will provide insight for the definition of specific Level 1 boundaries for micro aerial vehicles in remotely piloted flight.

The virtual environment is useful to test remote piloting with unconventional onboard visual cues. This is important in applications in which technical limitations may preclude complete real time data link during flight tests in the first development phase of the vehicle.