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AbstractBuildings are responsible for approximately 36% of carbon emissions in the European Union. Besides, gradual aging and a lack of adaptability and flexibility of buildings often lead to destructive interventions, resulting not only in higher costs but also in a large amount of construction and demolition waste (CDW). Recently, an innovative system (Ref. VEEP project) has been developed to recycle CDW for the manufacturing of energy‐efficient prefabricated concrete elements (PCE) for new building construction. By applying life cycle costing (LCC) and life cycle assessment (LCA), this study aimed to determine whether the use of VEEP PCE leads to lower carbon emission and lower associated costs over the life cycle of an exemplary four‐story residential building in the Netherlands than a business‐as‐usual (BAU) PCE scenario. This paper provides a case study on the alignment and/or integration of LCA and LCC in an independent and a combined manner (via monetization). This study examines how the internalization of carbon emission and discount rate will affect the final life cycle costs over a 40‐year life span. The simulation results show that the key to economic viability and environmental soundness of VEEP PCE is to reduce production cost and to optimize the thermal performance of the novel isolation material Aerogel; internalization of external cost monetarizes the environmental advantage thus slightly expands the cost advantage of low carbon options, but leads to larger uncertainty about the LCC result.

We show that sustainably harvesting 'blue' energy from the spontaneous mixing process of fresh and salty water can be boosted by varying the water temperature during a capacitive mixing process. Our modified Poisson-Boltzmann calculations predict a strong temperature dependence of the electrostatic potential of a charged electrode in contact with an adjacent aqueous 1:1 electrolyte. We propose to exploit this dependence to boost the efficiency of capacitive blue engines, which are based on cyclically charging and discharging nanoporous supercapacitors immersed in salty and fresh water, respectively [D. Brogioli, Phys. Rev. Lett. 103, 058501 (2009)]. We show that the energy output of blue engines can be increased by a factor of order two if warm (waste-heated) fresh water is mixed with cold sea water. Moreover, the underlying physics can also be used to optimize the reverse process of capacitive desalination of water.

AbstractNutrient enrichment can simultaneously increase and destabilise plant biomass production, with co‐limitation by multiple nutrients potentially intensifying these effects. Here, we test how factorial additions of nitrogen (N), phosphorus (P) and potassium with essential nutrients (K+) affect the stability (mean/standard deviation) of aboveground biomass in 34 grasslands over 7 years. Destabilisation with fertilisation was prevalent but was driven by single nutrients, not synergistic nutrient interactions. On average, N‐based treatments increased mean biomass production by 21–51% but increased its standard deviation by 40–68% and so consistently reduced stability. Adding P increased interannual variability and reduced stability without altering mean biomass, while K+ had no general effects. Declines in stability were largest in the most nutrient‐limited grasslands, or where nutrients reduced species richness or intensified species synchrony. We show that nutrients can differentially impact the stability of biomass production, with N and P in particular disproportionately increasing its interannual variability.

Increases of product in manufacturing processes have made its impact felt in Turning, one of the important branches of the industry. Increases in manufacturing also increase energy consumption. We can achieve this with efficiency studies in energy consumption. Energy efficiency studies to be carried out will reduce carbon emissions that will be revealed in turning processes and harm the environment. There are many studies on optimization of cutting parameters in turning processes. However, there are few studies on the effect of optimization of cutting parameters on energy efficiency and carbon emission values. This study has been trying to resolve this tartness. In the study, the efficiency calculation was made by extracting the exergy values of the processes of turning DIN 1.2367 steel material. In addition, processes in turning other metals can be determined and exergy calculations and efficiency values of these processes can be derived.

This study presents the clockspeed analysis of a peer group comprising six major integrated US energy companies with substantial US interstate natural gas pipeline business activities: El Paso, Williams, NiSource, Kinder Morgan, MidAmerican and CMS Energy. For this peer group, the three clockspeed accelerators have been benchmarked at both corporate level and gas transmission business level, using time-series analysis and cross-sectional analysis over a 6-year period (2002–2007). The results are visualized in so-called clockspeed radargraphs. Overall corporate clockspeed winners – over the performance period studied – are: Williams, El Paso and Kinder Morgan; MidAmerican is a close follower. Corporate clockspeed laggards are: CMS Energy and NiSource. The peer group ranking for the natural gas transmission business segment shows similar clockspeed winners, but with different ranking in the following order: Kinder Morgan, MidAmerican and El Paso; Williams is a close follower. Clockspeed laggards for the natural gas transmission segments coincide with the corporate clockspeed laggards of the peer group: CMS Energy and NiSource (over the performance period studied); laggards of the past may become clockspeed leaders of the future if adjustments are made. Practical recommendations are formulated for achieving competitive clockspeed optimization in the US gas transmission industry as a whole. Recommendations for clockspeed acceleration at individual companies are also given. Although the US natural gas market is subject to specific regulations and its own geographical dynamics, this study also provides hints for improving the competitive clockspeed performance of gas transmission companies elsewhere, in other world regions.

AbstractThe aim of the present contribution is to give a review on the recent work concerning Cd‐free buffer and window layers in chalcopyrite solar cells using various deposition techniques as well as on their adaptation to chalcopyrite‐type absorbers such as Cu(In,Ga)Se2, CuInS2, or Cu(In,Ga)(S,Se)2. The corresponding solar‐cell performances, the expected technological problems, and current attempts for their commercialization will be discussed. The most important deposition techniques developed in this paper are chemical bath deposition, atomic layer deposition, ILGAR deposition, evaporation, and spray deposition. These deposition methods were employed essentially for buffers based on the following three materials: In2S3, ZnS, Zn1 − xMgxO. Copyright © 2010 John Wiley & Sons, Ltd.

Modern district heating technologies have a great potential to make the energy sector more flexible and sustainable due to their capabilities to use energy sources of varied nature and to efficiently store energy for subsequent use. Central control tasks within these systems for the efficient and safe distribution of heat refer to the stabilization of overall system temperatures and the regulation of storage units state of charge. These are challenging goals when the networked and nonlinear nature of district heating system models is taken into consideration. In this letter, for district heating systems with multiple, distributed heat producers, we propose a decentralized control scheme to provably meet said tasks stably.