VANETs have emerged as an exciting research and application area. Increasingly vehicles are being equipped with embedded sensors, processing and wireless communication capabilities. This has opened a ...myriad of possibilities for powerful and potential life-changing applications on safety, efficiency, comfort, public collaboration and participation, while they are on the road. Although, considered as a special case of a Mobile Ad Hoc Network, the high but constrained mobility of vehicles bring new challenges to data communication and application design in VANETs. This is due to their highly dynamic and intermittent connected topology and different application’s QoS requirements. In this work, we survey VANETs focusing on their communication and application challenges. In particular, we discuss the protocol stack of this type of network, and provide a qualitative comparison between most common protocols in the literature. We then present a detailed discussion of different categories of VANET applications. Finally, we discuss open research problems to encourage the design of new VANET solutions.
After every major earthquake, the Earth rings like a bell for several days. These free oscillations of the Earth and the related propagating body and surface waves are routinely detected at ...broad-band seismographic stations around the world. In this book, F. A. Dahlen and Jeroen Tromp present an advanced theoretical treatment of global seismology, describing the normal- mode, body-wave, and surface-wave methods employed in the determination of the Earth's three-dimensional internal structure and the source mechanisms of earthquakes. The authors provide a survey of both the history of global seismological research and the major theoretical and observational advances made in the past decade. The book is divided into three parts. In the first, "Foundations, " Dahlen and Tromp give an extensive introduction to continuum mechanics and discuss the representation of seismic sources and the free oscillations of a completely general Earth model. The resulting theory should provide the basis for future scientific discussions of the elastic-gravitational deformation of the Earth. The second part, "The Spherical Earth, " is devoted to the free oscillations of a spherically symmetric Earth. In the third part, "The Aspherical Earth, " the authors discuss methods of dealing with the Earth's three-dimensional heterogeneity. The book is concerned primarily with the forward problem of global seismology--detailing how synthetic seismograms and spectra may be calculated and interpreted. As a long-needed unification of theories in global seismology, the book will be important to graduate students and to professional seismologists, geodynamicists, and geomagnetists, as well as to astronomers who study the free oscillations of the Sun and other stars.
The catalytic oxidation of p-xylene is investigated, focusing on the chemistry and kinetics responsible for it. Another focus is the industrial processing of terephthalic acid and an overview of ...hydrocarbon oxidation.
Patients with refractory severe aplastic anemia (SAA) who lack a matched sibling or unrelated donor need new therapeutic approaches. Hematopoietic SCT (HSCT) using mismatched or haploidentical ...related donors has been used in the past, but was associated with a significant risk of GVHD and mortality. Recently, the use of post-transplant cyclophosphamide (Cy) has been shown to be an effective strategy to prevent GVHD in recipients of haploidentical HSCT, but the majority of reports have focused on patients with hematology malignancies. We describe the outcome of 16 patients who underwent haploidentical transplantation using a reduced-intensity conditioning regimen with post-transplant Cy. Stem cell sources were BM (N=13) or PBSCs (N=3). The rate of neutrophil engraftment was 94% and of platelet engraftment was 75%. Two patients had secondary graft failure and were successfully salvaged with another transplant. Three patients developed acute GVHD being grades 2-4 in two. Five patients have died and the 1-year OS was 67.1% (95% confidence interval: 36.5-86.4%). In our small series, the use of a reduced-intensity conditioning with post-transplant Cy in haploidentical BMT was associated with high rates of engraftment and low risk of GVHD in patients with relapsed/refractory SAA.
The Indus basin heavily depends on its upstream mountainous part for the downstream supply of water while downstream demands are high. Since downstream demands will likely continue to increase, ...accurate hydrological projections for the future supply are important. We use an ensemble of statistically downscaled CMIP5 General Circulation Model outputs for RCP4.5 and RCP8.5 to force a cryospheric-hydrological model and generate transient hydrological projections for the entire 21st century for the upper Indus basin. Three methodological advances are introduced: (i) A new precipitation dataset that corrects for the underestimation of high-altitude precipitation is used. (ii) The model is calibrated using data on river runoff, snow cover and geodetic glacier mass balance. (iii) An advanced statistical downscaling technique is used that accounts for changes in precipitation extremes. The analysis of the results focuses on changes in sources of runoff, seasonality and hydrological extremes. We conclude that the future of the upper Indus basin's water availability is highly uncertain in the long run, mainly due to the large spread in the future precipitation projections. Despite large uncertainties in the future climate and long-term water availability, basin-wide patterns and trends of seasonal shifts in water availability are consistent across climate change scenarios. Most prominent is the attenuation of the annual hydrograph and shift from summer peak flow towards the other seasons for most ensemble members. In addition there are distinct spatial patterns in the response that relate to monsoon influence and the importance of meltwater. Analysis of future hydrological extremes reveals that increases in intensity and frequency of extreme discharges are very likely for most of the upper Indus basin and most ensemble members.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
The current study assessed two concrete mixes prepared using dolomite and barite/limonite aggregates to shield against both energetic photons and neutrons. After that, a designed mix which ...comprised barite/goethite aggregates plus fine-powdered boron carbide additive, was proposed to improve the overall radiation shielding properties and in the same time, doesn’t compromise or even improve the physic-mechanical properties of the mature concrete. The assessment started first with intensive experimental investigations to investigate the prepared mixes’ shielding capabilities against both γ-rays and fast neutrons. Then, analytical computations were performed via number of reliable software programs such as; Phy-X, NXCom, MRCsC, JANIS-4, and MCNP5, in order to confirm the experimental results and to validate the created Monte-Carlo models. Finally, an intensive radiation shielding assessment for all concrete mixes understudy using, mainly, the validated MCNP models, was performed. The obtained results have revealed the superiority of barite mixes over the dolomite mix concerning attenuating photons moreover, the proposed designed mix has shown superiority over the other two prepared mixes considering shielding against; energetic photons, fast/thermal neutrons, and secondary emitted γ-rays, which nominates this mix to be a suitable universal shield that can be used even in mixed radiation fields.
Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic ...have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead).
•Hg, Cd, Pb, Sn and As were analyzed in seafood sold in Andalusia (Southern Spain).•Most of samples analyzed were below maximum levels set by European Regulation.•Fish and shellfish analyzed do not seem to pose health risk for average consumers.•Recommended weekly intakes could be exceeded by eating regularly certain species.•The results found justify Spanish and European advice for vulnerable consumers.
We present ensembles of surface-ordered nanoparticle arrangements, which are formed by template-assisted self-assembly of monodisperse, protein-coated gold nanoparticles in wrinkle templates. ...Centimeter-squared areas of highly regular, linear assemblies with tunable line width are fabricated and their extinction cross sections can be characterized by conventional UV/vis/NIR spectroscopy. Modeling based on electrodynamic simulations shows a clear signature of strong plasmonic coupling with an interparticle spacing of 1–2 nm. We find evidence for well-defined plasmonic modes of quasi-infinite chains, such as resonance splitting and multiple radiant modes. Beyond elementary simulations on the individual chain level, we introduce an advanced model, which considers the chain length distribution as well as disorder. The step toward macroscopic sample areas not only opens perspectives for a range of applications in sensing, plasmonic light harvesting, surface enhanced spectroscopy, and information technology but also eases the investigation of hybridization and metamaterial effects fundamentally.
Glaciers in the high mountains of Asia (HMA) make a substantial contribution to the water supply of millions of people, and they are retreating and losing mass as a result of anthropogenic climate ...change at similar rates to those seen elsewhere. In the Paris Agreement of 2015, 195 nations agreed on the aspiration to limit the level of global temperature rise to 1.5 degrees Celsius ( °C) above pre-industrial levels. However, it is not known what an increase of 1.5 °C would mean for the glaciers in HMA. Here we show that a global temperature rise of 1.5 °C will lead to a warming of 2.1 ± 0.1 °C in HMA, and that 64 ± 7 per cent of the present-day ice mass stored in the HMA glaciers will remain by the end of the century. The 1.5 °C goal is extremely ambitious and is projected by only a small number of climate models of the conservative IPCC's Representative Concentration Pathway (RCP)2.6 ensemble. Projections for RCP4.5, RCP6.0 and RCP8.5 reveal that much of the glacier ice is likely to disappear, with projected mass losses of 49 ± 7 per cent, 51 ± 6 per cent and 64 ± 5 per cent, respectively, by the end of the century; these projections have potentially serious consequences for regional water management and mountain communities.
Pseudofrenelopsis and Brachyphyllum are two conifers that were part of the Lower Cretaceous (Aptian) taphoflora of the Crato Formation, Araripe Basin, northeastern Brazil. The former genus includes, ...so far, P. capillata and indeterminate species, whilst the latter is mainly represented by B. obesum, the most common plant megafossil recovered from that stratigraphic unit. Here, the stem and leaf anatomy of Pseudofrenelopsis sp. and B. obesum specimens is revisited, including the first report of some epidermal and vascular traits for both taxa from the Crato Formation. Along with its paleoecological significance, the new data suggest the presence of more than one Pseudofrenelopsis species in the Aptian taphoflora of the Araripe Basin and further support the taxonomic placement of B. obesum within Araucariaceae.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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