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491.
Die Bedeutung von Feststoffhaushalt und Sedimentdurchgängigkeit für eine nachhaltige Nutzung der Wasserkraft 总被引:1,自引:1,他引:0
Univ.-Prof. DI Dr. Helmut Habersack DI Beatrice Wagner Angelika Schoder DI Dr. Christoph Hauer 《?sterreichische Wasser- und Abfallwirtschaft》2013,65(9-10):354-361
The sediment regime and continuity in rivers are essential considerations from both river engineering and ecological standpoints, as can be seen e.g. in the problems concerning the riverbed degradation of the Danube east of Vienna. The imbalanced concentration of solids is caused e.g. by disruptions in flow, which include weirs and the reservoirs of hydroelectric power plants. In this context, the latter are above all affected by the problem of reservoir sedimentation, which can be detrimental to both energy production and flood protection. In order to counteract this sedimentation, measures are undertaken in the catchment area, in the reservoir or at the damming structure, which have to be optimized regarding their effectivity. In this regard, experimentation involving physical models, one-dimensional and multi-dimensional sediment transport models is becoming increasingly popular. Key questions that arise here concern the quality and availability of necessary measurement data, as well as the choice of model, and generally speaking a number of research questions remain open. From an ecological standpoint, a gravelly riverbed substrate is vital to the reproduction of certain fish species, which explains why the question of sediment continuity needs to be taken into account when new hydroelectric power plants are to be built or older ones are to be renovated. The (Austrian) national project SED_AT and the EU project SedAlp are currently working to identify key problems and research needs. One proposed approach is based on integral water resource management, in which the technical, economic and ecological optimization of reservoir management addresses the needs of the various stakeholders on the one hand, and includes the broad range of relevant natural processes (erosion, transfer, sedimentation, remobilization) on the other. 相似文献
492.
T.F. Conceição J.R. Bertolino G.M.O. Barra A.T.N. Pires 《Materials science & engineering. C, Materials for biological applications》2009,29(2):575-582
Nitrated and sulfonated poly (ether ether ketone) [SNPEEK] samples were prepared through sulfonation of nitrated PEEK (NPEEK) at different temperatures resulting in polymers with distinct sulfonation degrees (SD). The sulfonation occurred preferentially in the hydroquinone segment even after 81% of this moiety had been nitrated. Sulfonation in the benzophenone moiety was achieved only in 16% of this segment at the reaction temperature of 80 °C. The substitution degree was obtained through the TG curves, and values were in agreement with 1H NMR data when SD is much higher as ND (nitration degree). The highest SD obtained was 72%. Membranes of the sulfonated and nitrated PEEK (SNPEEK) were prepared by casting and showed good ductility depending on the substitution degree, with proton conductivity in the order of 10? 2 S cm? 1, an important characteristic in some applications, such as in fuel cells. 相似文献
493.
Offal of bovine, ovine and porcine are able to accumulate potentially toxic heavy metals, such as Cd and Pb, posing a risk for human health. For this reason, the Commission Regulation no. 466/2001 provided the maximum admitted levels for these metals in this kind of matrix (Cd, 500 ng g−1 in all kinds of offal; Pb, 500 ng g−1 in liver and 1000 ng g−1 in kidney). A method based on sector field inductively coupled plasma mass spectrometry for Cd and Pb quantification in calf liver was developed and further applied to offal of different animals. The uncertainty of measurements was calculated according to the Eurachem/Citac Guide. The method LoDs and LoQs were 3.5 and 11 ng g−1 for Cd, and 2.0 and 6.0 ng g−1 for Pb. The repeatability and the intra-laboratory reproducibility showed relative standard deviations equal to 2.25% and 1.99% for Cd and 1.49% and 6.55% for Pb. Relative expanded uncertainties at the mean value in calf liver were 4.74% for Cd and 13.8% for Pb. In Italian offal the following concentration intervals were found (in ng g−1): (i) Cd: calf, from <3.5 in spleen and lung to 96.4 in kidney; lamb, <3.5 in all offal; pig, 114 in liver and (ii) Pb: calf, from 4.03 in lung to 31.8 in liver; lamb, from 4.71 in heart to 279 in liver; pig, 9.19 in liver. 相似文献
494.
Valentina Ferradini Davide Vacca Beatrice Belmonte Ruggiero Mango Letizia Scola Giuseppe Novelli Carmela Rita Balistreri Federica Sangiuolo 《International journal of molecular sciences》2021,22(18)
Takotsubo syndrome (TTS), recognized as stress’s cardiomyopathy, or as left ventricular apical balloon syndrome in recent years, is a rare pathology, described for the first time by Japanese researchers in 1990. TTS is characterized by an interindividual heterogeneity in onset and progression, and by strong predominance in postmenopausal women. The clear causes of these TTS features are uncertain, given the limited understanding of this intriguing syndrome until now. However, the increasing frequency of TTS cases in recent years, and particularly correlated to the SARS-CoV-2 pandemic, leads us to the imperative necessity both of a complete knowledge of TTS pathophysiology for identifying biomarkers facilitating its management, and of targets for specific and effective treatments. The suspect of a genetic basis in TTS pathogenesis has been evidenced. Accordingly, familial forms of TTS have been described. However, a systematic and comprehensive characterization of the genetic or epigenetic factors significantly associated with TTS is lacking. Thus, we here conducted a systematic review of the literature before June 2021, to contribute to the identification of potential genetic and epigenetic factors associated with TTS. Interesting data were evidenced, but few in number and with diverse limitations. Consequently, we concluded that further work is needed to address the gaps discussed, and clear evidence may arrive by using multi-omics investigations. 相似文献
495.
Recent Developments in the Application of Phosphorescent Iridium(III) Complex Systems 总被引:1,自引:0,他引:1
Christoph Ulbricht Beatrice Beyer Christian Friebe Andreas Winter Ulrich S. Schubert 《Advanced materials (Deerfield Beach, Fla.)》2009,21(44):4418-4441
The recent developments in using iridium(III) complexes as phosphorescent emitters in electroluminescent devices, such as (white) organic light‐emitting diodes and light‐emitting electrochemical cells, are discussed. Additionally, applications in the emerging fields of molecular sensors, biolabeling, and photocatalysis are briefly evaluated. The basic strategies towards charged and non‐charged iridium(III) complexes are summarized, and a wide range of assemblies is discussed. Small‐molecule‐ and polymer‐based materials are under intense investigation as emissive systems in electroluminescent devices, and special emphasis is placed on the latter with respect to synthesis, characterization, electro‐optical properties, processing technologies, and performance. 相似文献
496.
Purnendu N. Singh Wesley W. Wallender Marco P. Maneta Stephen L. Lee Beatrice A. Olsen 《Canadian Metallurgical Quarterly》2010,136(5):289-299
This study uses five years of field data from the Land Retirement Demonstration Project located in western Fresno County of California to develop a comprehensive theoretical and numerical modeling framework to evaluate the specific site conditions required for a sustainable land retirement outcome based on natural drainage. Using field data, principles of mass balance in a control volume, the HYDRUS-1D software package for simulating one-dimensional movement of water, heat, and multiple solutes in variably-saturated media, and a model-independent parameter optimizer, the processes of soil water and solute movement in root zone and deep vadose zone were investigated. The optimization of unsaturated soil hydraulic parameters and downward flux (natural drainage) from the control volume against observed vadose zone salinity levels and shallow groundwater levels yield difficult to obtain natural drainage rate as a function of water table height within the control volume. The results show that the unsaturated soil hydraulic properties and the downward flux from the soil profile are the critical parameters. A “natural drainage approach” to sustainable land management for drainage-impaired land is proposed. With this approach it is feasible to design a sustainable land use regimen for drainage-impaired lands in general and retired lands in particular. 相似文献
497.
Mark I. Howells Sandra Jonsson Emilia Käck Philip Lloyd Kevin Bennett Tony Leiman Beatrice Conradie 《Energy Policy》2010
This paper describes how management and information failures can retard transitions from the traditional use of biomass fuel by low income rural consumers and micro-producers. 相似文献
498.
Federica Mariani Felipe Conzuelo Tobias Cramer Isacco Gualandi Luca Possanzini Marta Tessarolo Beatrice Fraboni Wolfgang Schuhmann Erika Scavetta 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(42)
A comprehensive understanding of electrochemical and physical phenomena originating the response of electrolyte‐gated transistors is crucial for improved handling and design of these devices. However, the lack of suitable tools for direct investigation of microscale effects has hindered the possibility to bridge the gap between experiments and theoretical models. In this contribution, a scanning probe setup is used to explore the operation mechanisms of organic electrochemical transistors by probing the local electrochemical potential of the organic film composing the device channel. Moreover, an interpretative model is developed in order to highlight the meaning of electrochemical doping and to show how the experimental data can give direct access to fundamental device parameters, such as local charge carrier concentration and mobility. This approach is versatile and provides insight into the organic semiconductor/electrolyte interface and useful information for materials characterization, device scaling, and sensing optimization. 相似文献
499.
Silvia Trabattoni Luisa Raimondo Marcello Campione Daniele Braga Vincent C. Holmberg David J. Norris Massimo Moret Andrea Ciavatti Beatrice Fraboni Adele Sassella 《Advanced Materials Interfaces》2015,2(18)
Rubrene (RUB) is one of the most studied organic semiconductors because, in the orthorhombic single‐crystal phase, it exhibits a record exciton diffusion length and one of the highest charge carrier mobilities ever reported. Here, thin films of oriented crystalline RUB are successfully grown in vacuum on millimeter‐sized (010)‐β‐alanine (β‐ala) single crystals with a step‐growth protocol, exploiting organic epitaxy. The experimental characterization demonstrates that these RUB films grow in the orthorhombic polymorph with the (100)RUB plane in contact with the (010)β‐ala surface and with precise azimuthal orientations. A complementary study of the RUB(100)/β‐ala(010) interface, performed by computational simulations, confirms the epitaxial relations expected by considering the molecular scale corrugations of the surfaces. Moreover, thanks to the wide transparency region of β‐ala, the RUB absorption bands in the UV range are directly detected for the first time. Finally, removal of the water‐soluble substrate enables the integration of the films in field effect transistors as high quality active organic layers. The characteristics of such RUB‐based devices confirm the quality and versatility of epitaxial thin films for use in organic electronics. 相似文献
500.
Globozoospermia is a form of teratozoospermia characterized by round‐headed spermatozoa and lack of acrosome. These spermatozoa cannot penetrate the zona pellucida of the oocyte, resulting in unsuccessful fertilization and infertility. When intracytoplasmic sperm injection is performed, the fertilization rate tends to be low. Until now, the causes of this disorder remain to be elucidated; however, mutations of some genes segregating on an autosomal recessive mode have been associated with this infertile condition. DPY19L2 (dpy‐19‐like 2 [Caenorhabditis elegans]) codes for a transmembrane protein expressed predominantly in spermatids, with specific localization limited to the internal nuclear membrane. Genetic defects in the DPY19L2 gene have been demonstrated the most frequent genetic cause of globozoospermia; however, intracellular molecular pathways related to its encoded protein are largely unknown. In this issue of Proteomics Clinical Applications, Guo and co‐workers investigate the proteome of gloobozoospermic spermatozoa. The authors identified 491 proteins that are differentially expressed in globozoospermia (370 are upregulated and 121 are downregulated in DPY19L2‐deficient globozoospermic sperm). Notably, the molecular defects identified by the authors are closely related to biological processes involved in acrosome formation, chromatin composition, sperm‐egg binding, and fertilization. 相似文献