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The presented article will describe an 'effect-cause' model for the purpose of simulating the energy consumption of DC fed light rail vehicles. The model will assess the advantages of hybrid vehicles in terms of energy consumption, network power and voltage variations, line current and losses; and will help sizing and designing a supercapacitor based energy storage system (ESS) for both on-board, and stationary applications. The proposed modeling needs to allow the ESS sizing according to the objective that needs to be achieved, being braking energy recovery, voltage drop compensation and peak power shaving the most common goals of ESS use in hybrid vehicles. The needed power and energy levels will vary in function of the vehicle features and the driving cycle followed. This all can be determined by the quasi-static simulation tool to ease the design process. Another objective of the modeling tool is to evaluate the behaviour of the vehicle power flow controller, which manages the power from/to the ESS in function of the state of several variables.

Fruiting kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson] vines were grown in two controlled temperatures of 28 / 22 and 17 / 12°C (day / night) for 160 and 215 d, to measure shoot and fruit growth and carbon demand, and to examine competition between fruit and the shoot. Leaf area, internode lengths, fruit diameters, photosynthesis and respiration were measured at regular intervals. The net daily carbon balance per shoot was determined from the net carbon acquisition of shoots, and carbon sequestration as shoot biomass. Vines grown at high temperature had 200% more leaf area, similar stem lengths and 100% more biomass than vines grown at low temperature. Leaf area expansion and stem extension were transiently reduced when fruit growth was maximal. Photosynthetic and respiration rates were affected by temperature, leading to net carbon acquisition of 450 g shoot–1 for 28 / 22°C-grown vines and 253 g shoot–1 for 17 / 12°C-grown vines, 54% being used for leaf, stem and fruit growth. Reallocation of carbon occurred from leaves to fruit, and the consequent reduction in leaf area strongly reduced the overall carbon balance compared with vegetative vines at similar temperatures. The data support the conclusion that at low temperatures especially, there is insufficient carbon to meet the full demands of both fruit and shoot growth.

Life Cycle Assessment is a tool to assess the environmental impacts and resources used throughout a product's life cycle, i.e., from raw material acquisition, via production and use phases, to waste management. The methodological development in LCA has been strong, and LCA is broadly applied in practice. The aim of this paper is to provide a review of recent developments of LCA methods. The focus is on some areas where there has been an intense methodological development during the last years. We also highlight some of the emerging issues. In relation to the Goal and Scope definition we especially discuss the distinction between attributional and consequential LCA. For the Inventory Analysis, this distinction is relevant when discussing system boundaries, data collection, and allocation. Also highlighted are developments concerning databases and Input-Output and hybrid LCA. In the sections on Life Cycle Impact Assessment we discuss the characteristics of the modelling as well as some recent developments for specific impact categories and weighting. In relation to the Interpretation the focus is on uncertainty analysis. Finally, we discuss recent developments in relation to some of the strengths and weaknesses of LCA.

Topical technological advances in power electronics and regulation systems have provided an opportunity for designing a high-efficiency PV system. High performance DC/DC converters should be developed to connect the low-voltage PV system to the high voltage DC-bus. These converters are used to regulate the output voltage and current of the PV system, to control the power flow and to track the maximum power point of the PV system. With the indispensable advantages of Interleaved Boost Converter (IBC) such as increased power capacity, passive components size reduction and output voltage ripple cancellation, it can be considered as a superior solution for PV systems. Therefore, this paper investigates and analyzes a three-phase interleaved DC/DC converter to enhance the dynamic performance of the PV system. The paper intends to design and implement two complete models of the standalone and grid-connected PV systems using Matlab/Simulink software package. In this paper, the dynamic model of the PV is described in detail. The simulation results are provided.

Abstract Sedimentological, limnological and palynological analyses of a sediment core from a lowland site in West-Java, Indonesia, provide a detailed palaeoenvironmental record for the Late Glacial and the Holocene. The record suggests open vegetation under inferred drier climatic conditions for the Late Glacial. However, there is no unequivocal evidence for cooler conditions at this time. The onset of the Holocene coincides with a change to more humid climatic conditions, with the development of a fern-rich closed forest vegetation type. Dramatic changes in diatom community composition provide a striking record of habitat change associated with lake shallowing, but this process appears to be a result of basin in-filling rather than variations in precipitation/evaporation balance associated with climatic fluctuations. Evidence for human impact on the vegetation development is restricted to the last few hundred years.

The specific technical challenges associated with the design of an ambient energy powered electronic system currently requires thorough knowledge of the environment of deployment, energy harvester characteristics and power path management. In this work, a novel flexible model for ambient energy harvesters is presented that allows decoupling of the harvester’s physical principles and electrical behavior using a three dimensional function. The model can be adapted to all existing harvesters, resulting in a design methodology for generic ambient energy powered systems using the presented model. Concrete examples are included to demonstrate the versatility of the presented design in the development of electronic appliances on system level.

Abstract Annual fiber sorghum (FS) and perennial giant reed (GR) cultivated in the Mediterranean area are interesting due to their high productivity under drought conditions and their potential use as lignocellulosic feedstock for biorefinery purposes. This study compares environmental constraints related to FS and GR produced on experimental farms (in the Campania region) using an attributional life cycle assessment (LCA) approach through appropriate modeling of the perennial cultivation. For both crops, primary data were available for agricultural management. Direct field emissions (DFEs) were computed, including the potential soil carbon storage (SCS). Giant reed showed the lowest burdens for all impact categories analyzed (most were in the range of 40%–80% of FS values). More apparent were the differences for climate change and freshwater eutrophication (respectively 80% and 81% lower for GR compared to FS). These results are due to the short-term SCS, experimentally detected in the perennial GR crop (about 0.25 ton C ha−1yr−1, with a global warming offsetting potential of about 0.03 ton CO2/tonGR dry biomass). The results are also due to the annual application of triple superphosphate at the sowing fertilization phase for FS, which occurs differently than it does for GR. Phosphorous fertilization was performed only when crops were being established and therefore properly spread along the overall crop lifetime. For both crops, after normalization, terrestrial acidification and particulate matter formation were relevant impact categories, as a consequence of the NH3 DFE by volatilization after urea were spread superficially. Therefore, the results suggest higher environmental benefits of the perennial crop than the annual crop. Integr Environ Assess Manag 2015;11:397–403. © 2015 SETAC Key Points An LCA comparison between Mediterranean annual and perennial feedstocks was conducted to explore their potential use for biorefinery purposes. Environmental constraints of crops fiber sorghum (annual) and giant reed (perennial), which exhibit high productivity under drought conditions, were investigated. Total burdens were largely affected by direct field emissions following fertilizer application. The perennial crop entailed a better environmental performance with reduced input and emissions.