A review on the complementarity of renewable energy sources: concept, metrics, application and future research directions

It is expected, and regionally observed, that energy demand will soon be covered by a widespread deployment of renewable energy sources. However, the weather and climate driven energy sources are characterized by a significant spatial and temporal variability. One of the commonly mentioned solutions to overcome the mismatch between demand and supply provided by renewable generation is a hybridization of two or more energy sources in a single power station (like wind-solar, solar-hydro or solar-wind-hydro). The operation of hybrid energy sources is based on the complementary nature of renewable sources. Considering the growing importance of such systems and increasing number of research activities in this area this paper presents a comprehensive review of studies which investigated, analyzed, quantified and utilized the effect of temporal, spatial and spatio-temporal complementarity between renewable energy sources. The review starts with a brief overview of available research papers, formulates detailed definition of major concepts, summarizes current research directions and ends with prospective future research activities. The review provides a chronological and spatial information with regard to the studies on the complementarity concept.Comment: 34 pages 7 figures 3 table

Effect of Service Stress on Impact Resistance, X-ray Diffraction Patterns, and Microstructure of 25s Aluminum Alloy

Report presents the results of a great number of tests made to determine the effect of service stresses on the impact resistance, the x-ray diffraction patterns, and the microstructure of 25s aluminum alloy. Many of the specimens were taken from actual propeller blades and others were cut from 13/16-inch rod furnished by the Aluminum Company of America

Fracture testing of weldments

Fracture toughness testing of welded structure

Underground radon gas concentrations related to earth tides

Over several years, radon concentrations have been recorded in a former gypsum mine near Walferdange (Luxembourg). Because of the exceptional quality of the site (thermal stability better than 0.01 7C/year, no running water, easy access, far enough from the oceans), today the mine hosts an underground laboratory for geodynamics and seismology with more than 25 permanent instruments that continuously record earth tides, earth quakes and meteorological parameters. One of the main interests in monitoring radon concentrations in this mine was to check the ability of earth tide effects on radon concentrations in the mine atmosphere. First results show that besides outside temperature and atmospheric air pressure, radon concentrations seem to be influenced by earth tides. Power spectra, calculated for different time series of radon concentrations, show the presence of both O1 (lunar declination) and M2 (principal lunar) tides. The increase in vertical extension and the decrease in gravity induced by earth tides in the bulk of the rocks may open supplementary pathways for radon and thus induce an increase of the radon transport through the rocks

Public transport policy in the Netherlands

Dutch public transport as a part of transport policy.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Recurrence of ventricular arrhythmias in ischaemic secondary prevention implantable cardioverter defibrillator recipients: long-term follow-up of the Leiden out-of-hospital cardiac arrest study (LOHCAT)

Aims to assess the long-term rate of mortality and the recurrence of potentially life-threatening ventricular arrhythmias in secondary prevention implantable cardioverter defibrillator (ICD) patients and to construct a model for baseline risk stratification.Methods and resultsSince 1996, all patients with ischaemic heart disease, receiving ICD therapy for secondary prevention of sudden death, were included in the current study. Patients were evaluated at implantation and during long-term follow-up. A total of 456 patients were included in the analysis and followed for 54 ± 35 months. During follow-up, 100 (22) patients died and ICD therapy was noted in 216 (47) patients, of which 138 (30) for fast, potentially life-threatening ventricular arrhythmia. Multivariate analysis revealed a history of atrial fibrillation or flutter (AF), ventricular tachycardia as presenting arrhythmia, and wide QRS and poor left ventricular ejection fraction as independent predictors of life-threatening ventricular arrhythmias. The strongest predictor was AF with a hazard ratio of 2.1 (95 confidence interval 1.3-3.2). On the basis of the available clinical data, it was not possible to identify a group which exhibited no risk on recurrence of potentially life-threatening ventricular arrhythmias.ConclusionIschaemic secondary prevention ICD recipients exhibit a high recurrence rate of potentially life-threatening ventricular arrhythmias. Factors that increase risk can be identified but, even with these factors, it was not possible to distinguish a recurrence-free group

Tolerability of gefitinib in patients receiving treatment in everyday clinical practice

Gefitinib (‘Iressa’, ZD1839), an epidermal growth factor receptor tyrosine kinase inhibitor, has recently been approved in several countries for use in advanced or metastatic non-small-cell lung cancer (NSCLC). In contrast to chemotherapies, which are generally used at or near their maximum-tolerated dose (MTD), gefitinib is used at an optimal biological dose (250 mg day−1), which is substantially below its MTD, minimising the risk of adverse events without compromising efficacy. Tolerability data from the compassionate use of gefitinib in the ‘Iressa’ Expanded Access Programme support the favourable safety profile of the agent reported in Phase I and II trials. In both settings, the majority of adverse drug reactions were mild/moderate and consisted mainly of grade 1/2 diarrhoea and skin rash. Although skin rash has been suggested to predict response to gefitinib, available data do not support this hypothesis. Overall, these tolerability data demonstrate that gefitinib has a relatively benign side-effect profile and is a well-tolerated treatment option for patients with previously treated NCSLC, who currently have few alternatives

E-Democracy and the European Public Sphere

The chapter starts with an outline of outstanding recent contributions to the discussion of the EU democratic deficit and the so-called “no demos” problem and the debate about European citizenship and European identity—mainly in the light of insights from the EU crisis. This is followed by reflections on the recent discussion on the state of the mass media-based European public sphere. Finally, the author discusses the state of research on the Internet’s capacity to support the emergence of a (renewed) public sphere, with a focus on options for political actors to use the Internet for communication and campaigning, on the related establishment of segmented issue-related publics as well as on social media and its two-faced character as an enabler as well as a distorting factor of the public sphere. The author is sceptic about the capacities of Internet-based political communication to develop into a supranational (European) public sphere. It rather establishes a network of a multitude of discursive processes aimed at opinion formation at various levels and on various issues. The potential of online communication to increase the responsiveness of political institutions so far is set into practice insufficiently. Online media are increasingly used in a vertical and scarcely in a horizontal or interactive manner of communication