• Energy Research
• 7. Clean energy close
• 11. Sustainability close
• AT close

Energy optimization of a Multiple Effect Evaporator house employed in the concentration of black liquor during Kraft Recovery process of Paper industries is an eye-catching concern pertinent to the present-day energy scenario. This article presents a proficient approach to solve the energy optimization problem of Multiple Effect Evaporator via metaheuristic optimizers. The proposed method first transforms the energy balance equations into the objective function to be optimized. Three metaheuristic algorithms viz. Harmony Search, Imperialist Competitive Algorithm and Water Cycle Algorithm have been utilized to carry out the optimization task. These metaheuristic approaches effectively figure out the optimum values of various process parameters including steam consumption, vapor temperatures and liquor flow rates, thereby yielding the optimum Steam Economy. Further, the present work investigates the effect of Boiling Point Elevation on the system performance. The results reveal that the inclusion of Boiling Point Elevation in the mathematical model causes a reduction in Steam Economy by 3.89%. The results also demonstrate the proficiency of these metaheuristic approaches towards the solution of a complex set of simultaneous non-linear algebraic equations. For comparative investigation of these metaheuristic approaches with reference to system performance parameters, tabular, evocative and graphical demonstrations have been utilized. Moreover, with the purpose of validating the strength, efficiency and exploratory capabilities of these metaheuristic algorithms, the acquired optimization results are compared with other competent and eminent algorithms to make a comprehensive evaluation.

The global climate change agenda proceeds at an incremental pace while the Earth is approaching critical tipping points in its development trajectory. Climate action at this pinnacle juncture needs to be greatly accelerated and rooted in the fundamentals of the problem—human beings’ disconnection from nature. This paper underscores the valuable role nature and nature-based solutions can play in addressing climate change at the city scale and its implications for broader sustainability. Urban ecosystems (nature in cities) are seen as an integral part of a proposed local climate action rubric wherein policy measures and integrated planning guide lowcarbon/impact development to create more resilient and sustainable urban environments. The use of green infrastructure is highlighted as a cost-effective means to contribute to mitigation and adaptation needs as well as to promote human wellbeing. The paper takes an exploratory view of the influence of ecosystem services, particularly cultural services, and its economics in relation to the individual and society to understand how biophilia can be nurtured to promote environmental stewardship and climate action.

In recent years, a wide range of strategies has been implemented in different EU-countries to increase the share of electricity generation from renewable energy sources. This paper evaluates the success of different regulatory strategies. The most important conclusions of this analysis are: (i) regardless of which strategy is chosen, it is of overriding importance that there should be a clear focus on the exclusive promotion of newly installed plants; (ii) a well-designed (dynamic) feed-in tariff system ensures the fastest deployment of power plants using Renewable Energy Sources at the lowest cost to society; (iii) promotion strategies with low policy risks have lower profit requirements for investors and, hence, cause lower costs to electricity customers.

The electrical ageing of photovoltaic modules during extended damp-heat tests at different stress levels is investigated for three types of crystalline silicon photovoltaic modules with different backsheets, encapsulants and cell types. Deploying different stress levels allows determination of an equivalent stress dose function, which is a first step towards a lifetime prediction of devices. The derived humidity dose is used to characterise the degradation of power as well as that of the solar cell's equivalent circuit parameters calculated from measured current–voltage characteristics. An application of this to the samples demonstrates different modes in the degradation and thus enables better understanding of the module's underlying ageing mechanisms. The analysis of changes in the solar cell equivalent circuit parameters identified the primary contributors to the power degradation and distinguished the potential ageing mechanism for each types of module investigated in this paper. © 2016 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. © 2016 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. This work was supported in part by the European Commission under FP7 grant N° 262533 SOPHIA (INFRA-2010- 1.1.22_CP-CSA-Infra) and by the Research Councils UK (RCUK) under project ‘Stability and Performance of Photovoltaics (STAPP)’ (contract no: EP/H040331/1).

Abstract In this paper, a process for the fermentative production of hydrogen is analysed with respect to its exergy efficiency. Parametric studies show the influence of used feedstock, applied process parameters as well as process and heat integration measures on exergy efficiency. It is shown that heat integration and recirculation of fermentor effluents reduce process irreversibilites and the amount of exergy leaving the process in waste streams. Nevertheless, depending on the used feedstock, a large amount of exergy leaves the process via by-products. Internal use of by-products and waste materials for providing process heat could increase chemical exergy efficiency up to 74%.

The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data- taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energy-loss calibration and transition radiation turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry. After the initial alignment, a transverse impact parameter resolution of 22.1+/-0.9 ��m and a relative momentum resolution ��p/p = (4.83+/-0.16) \times 10-4 GeV-1 \times pT have been measured for high momentum tracks. 34 pages, 25 figures