bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced Broadband RF Differential Rectifier Integrated with Archimedean Spiral Antenna for Wireless Energy Harvesting Applications
Authors: Mansour Mohamed , Le Polozec Xavier , Kanaya Haruichi
Published: February 2019

This work addresses the design and implementation of a broadband differential rectifier (DR) combined with an Archimedean spiral dipole antenna (ASDA) for wireless power harvesting at low incident power densities below 200 μ W/cm 2 . The proposed design exhibits an improved RF-DC conversion efficiency over a wide frequency range from 1.2 to 5 GHz. This frequency band is associated with several wireless communication services, for instance, ISM, WLAN, 5G, LTE, and GPS applications. The receiving planar ASDA exhibits circular polarization and has an average measured gain of 4.5 dBi from 1.2 to 5 GHz. To enable a wide operating bandwidth, the rectifier circuit is constituted by two architectures, designated A and B. Each scheme is designed to harvest power efficiently across a specific bandwidth. The optimal performance of both rectifiers are obtained using the nonlinear harmonic-balance simulations. The antenna–rectifier integration yields a compact rectenna with a high-efficiency performance over the intended bandwidth from 1.2 to 5 GHz for an input power of 9 dBm and terminal load resistance of 1 k Ω . The total measured RF-DC conversion efficiency is maintained above 30% across the entire frequency range with a peak value of 61% achieved at 1.2 GHz. In comparison with similar architectures, the proposed rectenna maintains a stable output efficiency despite the wide fluctuations in the input frequency and also has a minimum footprint size (58 × 55 mm 2 ).
Modal Identification of Output-Only Systems of Composite Discs Using Zernike Modes and MAC
Authors: Nguyen Minh , Filippatos Angelos , Langkamp Albert , Gude Maik
Published: February 2019

The analysis of the structural dynamic behaviour of composite rotor–discs by a valid description of the eigenfrequencies and mode shapes can provide significant information for action-taking before a failure occurs. Specifically, vibration-based diagnostic methods, which are able to take into consideration the interdependencies and sequential changes of the modal properties could benefit from such an analysis. Here, on the example of composite rotors, a correlation method for experimentally determined mode shapes is developed. For this purpose the Zernike polynomials are used to enhance the identification of mode shapes. Furthermore, the modal assurance criterion (MAC) in combination with the frequency response criterion and a data processing approach are applied in order to characterize changing modal properties of composite rotors. In addition, the developed algorithms can be further extended in order to simplify the experimental evaluation of the complex dynamic behaviour of composite structures.
A Support Vector Machine Based Approach for Predicting the Risk of Freshwater Disease Emergence in England
Authors: Hassani Hossein , Silva Emmanuel S. , Combe Marine , Andreou Demetra , Ghodsi Mansi , Yeganegi Mohammad Reza , Gozlan Rodolphe E.
Published: February 2019

Disease emergence, in the last decades, has had increasingly disproportionate impacts on aquatic freshwater biodiversity. Here, we developed a new model based on Support Vector Machines (SVM) for predicting the risk of freshwater fish disease emergence in England. Following a rigorous training process and simulations, the proposed SVM model was validated and reported high accuracy rates for predicting the risk of freshwater fish disease emergence in England. Our findings suggest that the disease monitoring strategy employed in England could be successful at preventing disease emergence in certain parts of England, as areas in which there were high fish introductions were not correlated with high disease emergence (which was to be expected from the literature). We further tested our model’s predictions with actual disease emergence data using Chi-Square tests and test of Mutual Information. The results identified areas that require further attention and resource allocation to curb future freshwater disease emergence successfully.
The Effects of Saline Stress on the Growth of Two Shrub Species in the Qaidam Basin of Northwestern China
Authors: Zhang Tan , Zhang Zhenzhong , Li Yuanhang , He Kangning
Published: February 2019

Soil salinization is a serious issue in the Qaidam Basin and significantly limits economic development. To explore the salt tolerance of two shrubs in this area, we determined several parameters, including the Soil and Plant Analyzer Development (SPAD), net photosynthetic rate (Pn), transpiration rate (Tr), intercellular carbon dioxide (Ci, μmol mol−1), stomatal conductance (Gs, umol m−2s−1), and water use efficiency (WUE) under different salt concentrations (0, 100, 200, 300, and 400 mmol·L−1). In addition, the shrubs of Elaeagnus angustifolia and Lycium barbarum of salt tolerance were evaluated. The photosynthetic parameters of E. angustifolia were more sensitive to salinity than those of L. barbarum, and SPAD, Pn, Tr, and WUE of E. angustifolia decreased significantly with increasing salt concentrations (p < 0.05), while in L. barbarum, SPAD, Pn, and Tr decreased significantly with increasing salt concentrations (p < 0.05), but the WUE of L. barbarum showed no significantly variation under the salt concentration gradient. The results of correlation matrix of photosynthetic index also indicated that the minimum salt tolerance of E. angustifolia and L. barbarum were 108.4 and 246.3 mmol·L−1, respectively. Our results provide a scientific basis for the selection of salt-tolerant plant species in of northwest China.
On the Nodal Structure of Nonlinear Stationary Waves on Star Graphs
Authors: Band Ram , Gnutzmann Sven , Krueger August J.
Published: February 2019

We consider stationary waves on nonlinear quantum star graphs, i.e., solutions to the stationary (cubic) nonlinear Schrödinger equation on a metric star graph with Kirchhoff matching conditions at the centre. We prove the existence of solutions that vanish at the centre of the star and classify them according to the nodal structure on each edge (i.e., the number of nodal domains or nodal points that the solution has on each edge). We discuss the relevance of these solutions in more applied settings as starting points for numerical calculations of spectral curves and put our results into the wider context of nodal counting, such as the classic Sturm oscillation theorem.
De Novo Assessment and Review of Pan-American Pit Viper Anticoagulant and Procoagulant Venom Activities via Kinetomic Analyses
Authors: Nielsen Vance G. , Frank Nathaniel , Afshar Sam
Published: February 2019

Snakebite with hemotoxic venom continues to be a major source of morbidity and mortality worldwide. Our laboratory has characterized the coagulopathy that occurs in vitro in human plasma via specialized thrombelastographic methods to determine if venoms are predominantly anticoagulant or procoagulant in nature. Further, the exposure of venoms to carbon monoxide (CO) or O-phenylhydroxylamine (PHA) modulate putative heme groups attached to key enzymes has also provided mechanistic insight into the multiple different activities contained in one venom. The present investigation used these techniques to characterize fourteen different venoms obtained from snakes from North, Central, and South America. Further, we review and present previous thrombelastographic-based analyses of eighteen other species from the Americas. Venoms were found to be anticoagulant and procoagulant (thrombin-like activity, thrombin-generating activity). All prospectively assessed venom activities were determined to be heme-modulated except two, wherein both CO and its carrier molecule were found to inhibit activity, while PHA did not affect activity (Bothriechis schlegelii and Crotalus organus abyssus). When divided by continent, North and Central America contained venoms with mostly anticoagulant activities, several thrombin-like activities, with only two thrombin-generating activity containing venoms. In contrast, most venoms with thrombin-generating activity were located in South America, derived from Bothrops species. In conclusion, the kinetomic profiles of venoms obtained from thirty-two Pan-American Pit Viper species are presented. It is anticipated that this approach will be utilized to identify clinically relevant hemotoxic venom enzymatic activity and assess the efficacy of locally delivered CO or systemically administered antivenoms.
RNA-Seq Transcriptome Profiling of the Queen Scallop (Aequipecten opercularis) Digestive Gland after Exposure to Domoic Acid-Producing Pseudo-nitzschia
Authors: Ventoso Pablo , Pazos Antonio J. , Pérez-Parallé M. Luz , Blanco Juan , Triviño Juan C. , Sánchez José L.
Published: February 2019

Some species of the genus Pseudo-nitzschia produce the toxin domoic acid, which causes amnesic shellfish poisoning (ASP). Given that bivalve mollusks are filter feeders, they can accumulate these toxins in their tissues. To elucidate the transcriptional response of the queen scallop Aequipecten opercularis after exposure to domoic acid-producing Pseudo-nitzschia, the digestive gland transcriptome was de novo assembled using an Illumina HiSeq 2000 platform. Then, a differential gene expression analysis was performed. After the assembly, 142,137 unigenes were obtained, and a total of 10,144 genes were differentially expressed in the groups exposed to the toxin. Functional enrichment analysis found that 374 Pfam (protein families database) domains were significantly enriched. The C1q domain, the C-type lectin, the major facilitator superfamily, the immunoglobulin domain, and the cytochrome P450 were among the most enriched Pfam domains. Protein network analysis showed a small number of highly connected nodes involved in specific functions: proteasome components, mitochondrial ribosomal proteins, protein translocases of mitochondrial membranes, cytochromes P450, and glutathione S-transferases. The results suggest that exposure to domoic acid-producing organisms causes oxidative stress and mitochondrial dysfunction. The transcriptional response counteracts these effects with the up-regulation of genes coding for some mitochondrial proteins, proteasome components, and antioxidant enzymes (glutathione S-transferases, thioredoxins, glutaredoxins, and copper/zinc superoxide dismutases).
Bed-Load Transport in Two Different-Sized Mountain Catchments: Mlynne and Lososina Streams, Polish Carpathians
Authors: Radecki-Pawlik Artur , Kuboń Piotr , Radecki-Pawlik Bartosz , Plesiński Karol
Published: February 2019

The prediction and calculation of the volume of gravel and/or sand transported down streams and rivers—called bed-load transport is one of the most difficult things for river engineers and designers because, in addition to field measurements, personnel involved in such activities need to be highly experienced. Bed-load transport treated by many engineers marginally or omitted and often receives only minor consideration from engineers or may be entirely disregarded simply because they do not know how to address the issue—in many cases, this is a fundamental problem in river management tasks such as: flood protection works; river bank protection works against erosion; building bridges and culverts; building water reservoirs and dams; checking dams and any other hydraulic structures. Thus, to share our experience in our paper, bed-load transport was calculated in two river/stream mountain catchments, which are different in terms of the characteristics of the catchment area and the level of river engineering works performed along the stream channel—both are tributaries of the Dunajec River and have similar Carpathian flysh geology. The studies were performed in the Mlyne stream and in the Lososina River in Polish Carpathians. Mlynne is one of the streams in the Gorce Mountains—it is prone to flash flooding events and has caused many problems with floods in the past. It flows partially in the natural river channel and partially in a trained river channel lined with concrete revetments. The stream bed load is accumulated in the reservoir upstream of the check dam. The Lososina River is one of the Polish Carpathian mountainous streams which crosses the south of the Beskid Wyspowy Mountains. It mostly has a gravel bed and it is flashy and experiences frequent flooding spring. At the mouth of the Lososina River, there is one of the largest Polish Carpathian artificial lakes—the Czchow lake. The Lososina mostly transports gravel as the bed load to the Czchow water reservoir where the sediment is deposited. In the early seventies, the Lososina was partly canalised, especially in places where passes inhabited areas. The paper compares the situation of bed-load transport in the Lososina River before and after engineering training works showing how much sediment is transported downstream along the river channel to the Czchow artificial lake. Also compared is the Mlynne bed load transport upstream and downstream from the check dam showing how much sediment might be transported and deposited in the reservoir upstream from the check dam and when one could expect this reservoir to be clogged.
Climate Change Impact on Flood Frequency and Source Area in Northern Iran under CMIP5 Scenarios
Authors: Maghsood Fatemeh Fadia , Moradi Hamidreza , Massah Bavani Ali Reza , Panahi Mostafa , Berndtsson Ronny , Hashemi Hossein
Published: February 2019

This study assessed the impact of climate change on flood frequency and flood source area at basin scale considering Coupled Model Intercomparison Project phase 5 General Circulation Models (CMIP5 GCMs) under two Representative Concentration Pathways (RCP) scenarios (2.6 and 8.5). For this purpose, the Soil and Water Assessment Tool (SWAT) hydrological model was calibrated and validated for the Talar River Basin in northern Iran. Four empirical approaches including the Sangal, Fill–Steiner, Fuller, and Slope-based methods were used to estimate the Instantaneous Peak Flow (IPF) on a daily basis. The calibrated SWAT model was run under the two RCP scenarios using a combination of twenty GCMs from CMIP5 for the near future (2020–2040). To assess the impact of climate change on flood frequency pattern and to quantify the contribution of each subbasin on the total discharge from the Talar River Basin, Flood Frequency Index (FFI) and Subbasin Flood Source Area Index (SFSAI) were used. Results revealed that the projected climate change will likely lead to an average discharge decrease in January, February, and March for both RCPs and an increase in September and October for RCP 8.5. The maximum and minimum temperature will likely increase for all months in the near future. The annual precipitation could increase by more than 20% in the near future. This is likely to lead to an increase of IPF. The results can help managers and policy makers to better define mitigation and adaptation strategies for basins in similar climates.
Optimizing the Formation of DMAs in a Water Distribution Network through Advanced Modelling
Authors: Chatzivasili Stavroula , Papadimitriou Katerina , Kanakoudis Vasilis
Published: February 2019

Water pressure management in a water distribution network (WDN) is a key component applied to achieve desirable water quality as well as a trouble-free operation of the network. This paper presents a hybrid, two-stage approach, to provide optimal separation of a WDN into District Metered Areas (DMAs), improving both water age and pressure. The first stage aims to divide the WDN into smaller areas via the Geometric Partitioning method, which is based on Recursive Coordinate Bisection (RCB). Subsequently, the Student’s t-mixture model (SMM) is applied to each area, providing an optimal placement of isolation valves and separating the network in DMAs. The model is evaluated on a realistic network generated through Watergems and is compared against one variation of it implemented, including the Gaussian Mixture Model (GMM) as well as the Genetic Algorithm (GA) approach, obtaining impressive performance. The implementation of both stages was deployed in a MATLAB environment through the Epanet toolkit. The proposed system is very promising, especially for large size WDNs due to the decreased running time and noteworthy reduction of pressure and water age.
Hydraulic Modeling and Evaluation Equations for the Incipient Motion of Sandbags for Levee Breach Closure Operations
Authors: Sattar Ahmed M. A. , Bonakdari Hossein , Gharabaghi Bahram , Radecki-Pawlik Artur
Published: February 2019

Open channel levees are used extensively in hydraulic and environmental engineering applications to protect the surrounding area from inundation. However, levees may fail to produce an unsteady flow that is inherently three dimensional. Such a failure may lead to a destructive change in morphology of the river channel and valley. To avoid such a situation arising, hydraulic laboratory modeling was performed on an open channel levee breach model capturing velocity, in x, y and z plans, at selected locations in the breach. Sandbags of various shapes and sizes are tested for incipient motion by the breach flow. We found that a prism sandbag has a better hydrodynamic characteristic and more stability than spherical bags with the same weight. Experimental results are then used to evaluate existing empirical equations and to develop more accurate equations for predicting critical flow velocity at the initial stage of sandbag motion. Results showed the superior predictions a few of the equations could be considered with an uncertainty range of ±10%. These equations explained the initial failed attempts of the United States Army Corps of Engineers (USACE) for breach closure of the case study, and confirmed the experimental results are simulating the case study of breach closure.
Numerical Research on the Resistance Reduction of Air Intake
Authors: Du Lei , Sun Hanbing , Jiang Yi , Li Ping
Published: February 2019

In order to investigate the drag-reducing effect of air intake, forward motion of planing trimaran models in calm water were simulated for Froude numbers ranging from 3.14–5.87. The hull body motion is implemented by coupling the fluid solver with motion solver. Numerical results were compared with the experimental data and showed good agreement. Contrastive calculations of models with and without air intake show that the air intake presents evident drag-reducing effect when Froude number is above 4.49, the cambered configuration of air intake could amplify air cavity and thus decrease fractional resistance. CFD incremental studies were subsequently carried out for the camber of air intake, it is found that the model with chamber-shortened air intake shows the worst resistance performance, while enlarging air intake chamber could reduce resistance at Froude numbers between 4.06 and 4.97.
Adsorption of Aqueous As (III) in Presence of Coexisting Ions by a Green Fe-Modified W Zeolite
Authors: Medina-Ramirez Adriana , Gamero-Melo Procoro , Ruiz-Camacho Beatriz , Minchaca-Mojica Jesus Isaac , Romero-Toledo Rafael , Gamero-Vega Karen Yazmin
Published: February 2019

The high toxicity of arsenite and the difficulty to remove it is one of the main challenges for water treatment. In the present work the surface of a low cost zeolite was modified by chemical treatment with a ferrous chloride to enhance its arsenite adsorption capacity. The effect of pH, ions coexistence, concentration, temperature and dosage was studied on the adsorption process. Additionally, the Fe-modified W zeolite was aged by an accelerated procedure and the regeneration of the exhausted zeolite was demonstrated. The Fe-modified W zeolite was stable in the pH range of 3 to 8 and no detriment to its arsenite removal capacity was observed in the presence of coexisting ions commonly found in underground water. The studies showed that the adsorption of As (III) on Fe-modified W zeolite is a feasible, spontaneous and endothermic process and it takes place by chemical bonding. The exhausting process proved the adsorption of 0.20 mg g−1 of As (III) by the Fe-modified W zeolite and this withstand at least five aging cycles without significant changes of its arsenite adsorption capacity. Fe-modified W zeolite prepared from fly ash might be a green and low-cost alternative for removal of As (III) from groundwater.
Bio-Removal of Methylene Blue from Aqueous Solution by Galactomyces geotrichum KL20A
Authors: Contreras Margarita , Grande-Tovar Carlos David , Vallejo William , Chaves-López Clemencia
Published: February 2019

The conventional treatments used to remove dyes produced as a result of different industrial activities are not completely effective. At times, some toxic by-products are generated, affecting aquatic ecosystems. In this article, an efficient use of microorganisms is presented as a biodegradation technique that is a safe environmental alternative for the benefit of aquatic life. A strain of the yeast Galactomyces geotrichum KL20A isolated from Kumis (a Colombian natural fermented milk) was used for Methylene Blue (MB) bioremoval. Two parameters of the bioremediation process were studied at three different levels: initial dye concentration and growth temperature. The maximum time of MB exposure to the yeast was 48 h. Finally, a pseudo-first-order model was used to simulate the kinetics of the process. The removal percentages of MB, by action of G. geotrichum KL20A were greater than 70% under the best operating conditions and in addition, the kinetic simulation of the experimental results indicated that the constant rate of the process was 2.2 × 10-2 h−1 with a half time for biotransformation of 31.2 h. The cytotoxicity test based on the hemolytic reaction indicated that by-products obtained after the bioremoval process reached a much lower percentage of hemolysis (22%) compared to the hemolytic activity of the negative control (100%). All of these results suggest that the strain has the capacity to remove significant amounts of MB from wastewater effluents.
The Effects of Land Use and Climate Change on the Water Yield of a Watershed in Colombia
Authors: Villamizar Sandra R. , Pineda Sergio M. , Carrillo Gustavo A.
Published: February 2019

Land use and climate are two determinant factors of water yield within a watershed. Understanding the effects of these two variables is key for the decision-making process within watersheds. Hydrologic modeling can be used for this purpose and the integration of future climate scenarios to calibrated models widens the spectrum of analysis. Such types of studies have been carried out in many areas of the world, including the Amazon Basin of South America. However, there is a lack of understanding on the effect of land use/land cover and climate change on Andean watersheds of this continent. Our study focused on the evaluation of water yield under different land use and climate scenarios using the semi-distributed hydrological model known as the Soil and Water Assessment Tool (SWAT) model. We worked on the Tona watershed (Colombia, South America), the most important source of water for a metropolitan population. Our results compared water yield estimates for historical conditions (1987–2002) with those of future combined scenarios for land use and climate for the 2006–2050 period. The modeling effort produced global estimates of water yield (average annual values) and, at the subwatershed level, identified strategic areas on which the protection and conservation activities of water managers can be focused.
Including Variability across Climate Change Projections in Assessing Impacts on Water Resources in an Intensively Managed Landscape
Authors: Han Bangshuai , Benner Shawn G. , Flores Alejandro N.
Published: February 2019

In intensively managed watersheds, water scarcity is a product of interactions between complex biophysical processes and human activities. Understanding how intensively managed watersheds respond to climate change requires modeling these coupled processes. One challenge in assessing the response of these watersheds to climate change lies in adequately capturing the trends and variability of future climates. Here we combine a stochastic weather generator together with future projections of climate change to efficiently create a large ensemble of daily weather for three climate scenarios, reflecting recent past and two future climate scenarios. With a previously developed model that captures rainfall-runoff processes and the redistribution of water according to declared water rights, we use these large ensembles to evaluate how future climate change may impact satisfied and unsatisfied irrigation throughout the study area, the Treasure Valley in Southwest Idaho, USA. The numerical experiments quantify the changing rate of allocated and unsatisfied irrigation amount and reveal that the projected temperature increase more significantly influences allocated and unsatisfied irrigation amounts than precipitation changes. The scenarios identify spatially distinct regions in the study area that are at greater risk of the occurrence of unsatisfied irrigation. This study demonstrates how combining stochastic weather generators and future climate projections can support efforts to assess future risks of negative water resource outcomes. It also allows identification of regions in the study area that may be less suitable for irrigated agriculture in future decades, potentially benefiting planners and managers.
METHODOLOGICAL ASPECTS OF A QUESTIONNAIRE RESEARCHING TRANSPORTATION LINKS
Authors: Litvinenko Michail , Palšaitis Ramūnas
Published: February 2019

Changes of foreign trade conditions also bring changes of the main transport routes and directions. Lithuanian transport companies must perfect their ability to adapt in changing environment, to predict and reorient to the possible changes in the flow of goods, to observe changes and tendencies, in short to build a new foundation and appliance of transportation technologies. To aid this a questionnaire researching transport must be made. This article covers the analysis of the planning and conducting of the research and the data processing methodology used to determine the main directions of the flow of goods of Lithuanian transport companies as well as the criteria concerning competitiveness among the companies.
VEHICLE SPEED CONTROL USING ROAD BUMPS: PART 2
Authors: Oke Sunday Ayoola , Salau Tajudeen Abiola Ogunniyi , Adeyefa Adebayo Oludele
Published: February 2019

In a previous publication in this journal the framework for the development of a model for the road bump problem was laid. The current paper focuses on the aspect of determining the effective distance between two consecutive road bumps developing equations governing the velocity and the wavelength of the motion of the vehicle. The wave equation is re‐modelled connecting the isolation factor, linear velocity, wavelength and the frequency of motion of the vehicle over a road bump. A new set of equations is developed to extend the framework earlier presented in Salau et al. The feasibility of the model is demonstrated by its behaviour in graph and simulated data generation.
CARGO PIERS IN DREDGING HARBOUR WATERS
Authors: Kudzys Antanas , Vaicekauskas Laimutis Jonas
Published: February 2019

Structural behaviour and reliability peculiarities of cargo piers in deepened harbour waters are discussed. Deterministic and probabilistic reliability assessment methods for permeable cargo piers exposed to lateral berthing actions and gravity permanent and variable loads are analysed. Some new methodological approaches to probabilistic reliability assessment of existing cargo piers are presented. The survival probability assessment of pier piles is based on their irreversible serviceability and safety margins. The numerical example illustrates the virtue of probability‐based approaches and methods of design practice of cargo piers.
DETERMINATION OF CAR RUN UP - BRAKING AND MANOEUVRING PARAMETERS IN AN EMERGENCY SITUATION IN THE CASE OF LIMITED ROAD SEGMENT
Authors: Lukoševičiene Ona , Pečeliūnas Robertas
Published: February 2019

As the traffic intensity on roads increases, the number of road accidents also increases and the situations become more and more complicated. The presented method of reconstruction of preaccidental situations with the purpose of examination of road accident mechanisms can be widely used for the investigation of road accidents of different nature and for the determination of their reasons, the distance run by a car, the time of its run and speed which can be reached during the run up and followed by braking in road segments between two manoeuvres in a road segment of limited length. This method is being widely used in Lithuania for the investigation of accidental situations and for the assurance of law and order.
RESEARCH INTO FREIGHT TRANSPORT QUEUING AT CUSTOMS CONTROL POSTS
Authors: Jarašūniene Aldona
Published: February 2019

The changes after Lithuania joined the EU and customs union are analyzed here. For the transport flows forecast and the analysis of traffic at the border theories of multidimensional regression, correlation analysis and wholesale service flows are applied here, the statistical data is processed. According to these mathematical theories and methods a transport flow which will cross the outer border of the EU is forecasted. The method how to predict the amount of transport at a certain border is shown here. The research is performed to find out which custom links have problems. Conclusions and few suggestions how to quicken road traffic flows through Lithuanian customs are also presented in this work.
NUMERICAL MODELLING OF MAGNETIC SHIELDING BY A CYLINDRICAL FERROFLUID LAYER
Authors: Lavrova Olga , Polevikov Viktor , Polevikov Sergei
Published: February 2019

A coupled method of finite differences and boundary elements is applied to solve a nonlinear transmission problem of magnetostatics. The problem describes an interaction of a uniform magnetic field with a cylindrical ferrofluid layer. Ferrofluid magnetisations, based on expansions over the Langevin law, are considered to model ferrofluids with a different concentration of ferroparticles. The shielding effectiveness factor of the cylindrical thick-walled ferrofluid layer is calculated depending on intensities of the uniform magnetic field and on thickness of the ferrofluid layer.
GREEN’S FUNCTION AND EXISTENCE OF SOLUTIONS FOR A THIRD-ORDER THREE-POINT BOUNDARY VALUE PROBLEM
Authors: Smirnov Sergey
Published: February 2019

The solutions of third-order three-point boundary value problemx′′′+f(t,x) = 0, t∈[a,b],x(a) =x′(a) = 0, x(b) =kx(η),whereη∈(a,b),k∈R,f∈C([a,b]×R,R) andf(t,0)6= 0, are the subject of thisinvestigation. In order to establish existence and uniqueness results for the solutions,attention is focused on applications of the corresponding Green’s function. As anapplication, also one example is given to illustrate the result.Keywords:Green’s function, nonlinear boundary value problems, three-point boundaryconditions, existence and uniqueness of solutions.
An Embedded X-Ray Source Shines through the Aspherical AT 2018cow: Revealing the Inner Workings of the Most Luminous Fast-evolving Optical Transients
Authors: Margutti R. , Metzger B. D. , Chornock R. , Vurm I. , Roth N. , Grefenstette B. W. , Savchenko V. , Cartier R. , Steiner J. F. , Terreran G. , Margalit B. , Migliori G. , Milisavljevic D. , Alexander K. D. , Bietenholz M. , Blanchard P. K. , Bozzo E. , Brethauer D. , Chilingarian I. V. , Coppejans D. L. , Ducci L. , Ferrigno C. , Fong W. , Götz D. , Guidorzi C. , Hajela A. , Hurley K. , Kuulkers E. , Laurent P. , Mereghetti S. , Nicholl M. , Patnaude D. , Ubertini P. , Banovetz J. , Bartel N. , Berger E. , Coughlin E. R. , Eftekhari T. , Frederiks D. D. , Kozlova A. V. , Laskar T. , Svinkin D. S. , Drout M. R. , MacFadyen A. , Paterson K.
Published: February 2019

We present the first extensive radio to γ-ray observations of a fast-rising blue optical transient, AT 2018cow, over its first ∼100 days. AT 2018cow rose over a few days to a peak luminosity L
pk ∼ 4 × 1044 erg s−1, exceeding that of superluminous supernovae (SNe), before declining as L ∝ t
−2. Initial spectra at δt ≲ 15 days were mostly featureless and indicated large expansion velocities v ∼ 0.1c and temperatures reaching T ∼ 3 × 104 K. Later spectra revealed a persistent optically thick photosphere and the emergence of H and He emission features with v ∼ 4000 km s−1 with no evidence for ejecta cooling. Our broadband monitoring revealed a hard X-ray spectral component at E ≥ 10 keV, in addition to luminous and highly variable soft X-rays, with properties unprecedented among astronomical transients. An abrupt change in the X-ray decay rate and variability appears to accompany the change in optical spectral properties. AT 2018cow showed bright radio emission consistent with the interaction of a blast wave with v
sh ∼ 0.1c with a dense environment (

for v

w
 = 1000 km s−1). While these properties exclude 56Ni-powered transients, our multiwavelength analysis instead indicates that AT 2018cow harbored a “central engine,” either a compact object (magnetar or black hole) or an embedded internal shock produced by interaction with a compact, dense circumstellar medium. The engine released ∼1050–1051.5 erg over ∼103–105 s and resides within low-mass fast-moving material with equatorial–polar density asymmetry (M
ej,fast ≲ 0.3 M
☉). Successful SNe from low-mass H-rich stars (like electron-capture SNe) or failed explosions from blue supergiants satisfy these constraints. Intermediate-mass black holes are disfavored by the large environmental density probed by the radio observations.
Ripple Patterns in In-plane Velocities of OB Stars from LAMOST and Gaia
Authors: Cheng Xinlun , Liu Chao , Mao Shude , Cui Wenyuan
Published: February 2019

With about 12,000 OB type stars selected from the LAMOST and Gaia survey, we study their three-dimensional velocity distribution over the range of galactocentric radius from 6 to 15 kpc in the Galactic disk plane. A clear ripple pattern in the radial velocity (V

R
) map is shown. The median V

R
reaches −8 km s−1 at R ∼ 9 kpc, then increases to ∼0 km s−1 at R ∼ 12 kpc, and later declines to below −10 km s−1 beyond R ∼ 13 kpc. The median azimuthal velocity (V

ϕ
) map shows a similar pattern but has roughly one-quarter phase difference with the radial velocity. Although the ripple of negative V

R
at ∼9 kpc extends to about 40◦ in the azimuth angle, it does not align with either the Local or the Perseus spiral arms. Moreover, the farther ripple beyond 13 kpc does not match the Outer spiral arm either. This indicates that the non-axisymmetric kinematic features are not induced by perturbations of known spiral structures. The central rotating bar cannot lead to such patterns in the outer disk either. External perturbation of a dwarf galaxy or a dark matter sub-halo can induce such patterns, but this requires more evidence from both observations and simulations. The V

ϕ
map in the Z–V

Z
plane of the OB stars is also investigated. Despite asymmetry to some degree, no spiral pattern is found. This is reasonable as most of the OB stars have ages that are much younger than 100 Myr, which is smaller than one orbital period around the Galactic center.
Influenza A (H1N1)-associated severe complications; hemolytic uremic syndrome, myocarditis, acute necrotizing encephalopathy
Authors: Öcal Demir Sevliya , Atıcı Serkan , Kepenekli Kadayifci Eda , Akkoç Gülşen , Yakut Nurhayat , İnceköy Girgin Feyza , Yalındağ Öztürk Nilüfer , Soysal Ahmet
Published: February 2019

Influenza is a generally self-limited infection agent that only rarely causes severe complications. To increase awareness about its serious complications, we report three cases of influenza A (H1N1) infection complicated with hemolytic uremic syndrome, myocarditis and acute necrotizing encephalopathy. In all three cases, nasopharyngeal samples confirmed influenza A (H1N1) infection by antigen test and multiplex PCR detection. The first case, a 3-year-old girl, had respiratory distress, anemia, thrombocytopenia and renal failure at admission, and was diagnosed with hemolytic uremic syndrome. Supportive treatment and oseltamivir did not prevent the development of chronic renal failure. The second case, a 5-year-old girl admitted with lethargia and flu-like symtoms and was diagnosed with myocarditis and cardiogenic shock. Oseltamivir and supportive treatment including extra-corporeal membrane oxygenation (ECMO) failed. She died on the 3rd day of admission. The third case, a 21-month-old boy, presented with decreased level of consciousness and was diagnosed with acute necrotizing encephalopathy with the aid of cranial magnetic resonance imagining (MRI). He was discharged without any neurological sequelae three weeks after admission. It should be kept in mind that influenza virus does not always cause a self-limited flu. Multidisciplinary management, early diagnosis and antiviral treatment are critical for the disease and to prevent its life-threatening complications.
Spatial and temporal analysis of severe fever with thrombocytopenia syndrome in Zhejiang Province, China, 2011 - 2015
Authors: Li Fudong , He Fan , Sun Jimin , Zhai Yujia , Jiang Jianmin , Lin Junfen
Published: February 2019

Introduction: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease first discovered in northeast and central China in 2009, and SFTS cases increased year by year in China. This study aimed to identify the spatial and temporal clusters of SFTS in Zhejiang Province, China.

Methodology: We analyzed the surveillance data of SFTS in Zhejiang Province during 2011 - 2015. Descriptive statistics were used to analyze the general characteristics and overall trend of SFTS. Circular statistic method was utilized to identify the seasonality. Space–time scan analysis was performed to explore the high risk spatio-temporal clusters of SFTS cases at county level.

Results: A total of 194 confirmed SFTS cases were reported in Zhejiang Province during 2011 - 2015. We found a significant increase in overall time trend since 2011. The seasonality was statistically significant (P < 0.001), with a mean date (95% CI) of 21st June (12th ~ 30th in June). Totally 21 (23%) counties reported the occurrence of SFTS, which gradually spread throughout Zhejiang. Three spatio-temporal clusters were detected, with one principle cluster (Daishan County, RR 234.48, June 2013 - November 2015) and two secondary clusters (6 counties, RR 30.73, April - October in 2015; Anji County, RR 373.26, May 2014).

Conclusions: Our results suggested that SFTS has increased and spatially expanded over the past years, with a remarkable seasonality. Three spatio-temporal clusters were identified. These findings are important for the improvement of SFTS surveillance and control strategies.
Knowledge, attitude, behaviour of the future healthcare professionals towards the self-medication practice with antibiotics
Authors: Benameur Tarek , Al-Bohassan Hassan , Al-Aithan Abdullah , Al-Beladi Abdullah , Al-Ali Hassan , Al-Omran Hassan , Saidi Neji
Published: February 2019

Introduction: Self-medication with antibiotics (SMA) is a major health problem in the developing world including the kingdom of Saudi Arabia (KSA). This practice remains an emerging challenge for the healthcare providers. A few previous studies have estimated the prevalence of SMA among the general population of KSA, but there had been no such studies on healthcare students.

We aimed to estimate the prevalence of SMA among medical, non-medical students and to evaluate its determinants.

Methodology: A survey-based cross-sectional study using validated questionnaire was conducted amongst students at King Faisal University in KSA. Chi-square test and logistic regression analysis were applied to identify the determinants of SMA.

Results: The prevalence of SMA was 58.4% with significantly lower proportion among medical students. Tonsillitis was the most common symptom for which SMA was used and was reported by a significantly higher proportion of medical (54.1%) students. Despite, the awareness of medical students about SMA is unsafe and mal-practice (79.9%), the prevalence of SMA practice remains high. Logistic regression analysis showed that students who incorrectly, identified the effectiveness of antibiotics in treating bacterial infections, the reasons of the antibiotics discontinuation had a higher likelihood to SMA. (OR = 2.16, 95% CI: 1.52-4.503, P = 0.001), (OR = 1.575, 95% CI: 0.923-2.686, P = 0.09), respectively.

Conclusions: SMA remains noticeably high among the medical students. To overcome this problem, we highly recommend improving the health education to better address this malpractice and improve the students’ knowledge, attitudes and awareness towards the antibiotics use and prescription pattern.
Autour du « rouge végétal » : entrepreneurs, marché des cosmétiques et institutions savantes à la fin du xviii e siècle
Authors: Lanoë Catherine
Published: February 2019

Dans la seconde moitié du XVIIIe siècle, le fard rouge d’origine végétale s’impose comme le produit emblématique d’une cosmétique renouvelée. Sa consommation est croissante et sa confection désormais proscrit l’usage des substances minérales et métalliques, identifiées comme toxiques. Plusieurs inventeurs portent le débat devant l’Académie Royale des Sciences dans les années 1770, puis devant la Société royale de médecine dans les années 1780. Leurs démarches et leurs démêlés devant les institutions savantes, leurs stratégies commerciales et publicitaires, les interventions des plus grands chimistes du temps, reconstituées en croisant les archives de différents fonds, permettent de mettre en évidence les caractéristiques de leur démarche inventive, mais surtout de souligner de véritables savoir-faire d’entrepreneurs, capables à la fois de mobiliser les ressources institutionnelles à leur disposition, de construire un discours capable de séduire le public et de profiter des possibilités offertes par le marché. Classification JEL : N00, N84, O14, O13
Le lobby juif pro-israélien des États-Unis et la (difficile) validation de l’accord sur le nucléaire iranien par le Congrès en 2015
Authors: Pelouard Marion , Zarifian Julien
Published: February 2019

L’accord international sur le nucléaire iranien signé en juillet 2015, qui vise à empêcher l’Iran d’accéder à l’arme nucléaire, est alors jugé historique par l’administration Obama mais pas assez strict par le gouvernement israélien. Également critiqué aux États-Unis par l’opposition républicaine, il est soumis à un vote de blocage au Congrès en septembre 2015. Les groupes de pression juifs américains prennent position pour ou contre l’accord et mènent des campagnes de lobbying pour ou contre son adoption au Congrès. Les organisations de l’establishment comme l’AIPAC et l’AJC et d’autres groupes conservateurs comme The Israel Project cherchent à convaincre les élus de voter contre l’accord, tandis que les organisations progressistes telles que J Street et l’Americans for Peace Now militent pour le faire adopter – montrant ainsi le clivage de ces groupes. Finalement, le Congrès entérine le passage de l’accord. Ce vote s’explique largement par l’influence de Barack Obama sur les élus démocrates mais marque aussi une défaite et une baisse d’influence – relative – des groupes juifs pro-israéliens de l’establishment et un succès des groupes plus récents – succès tout aussi relatif, d’autant que le successeur d’Obama à la Maison blanche, Donald Trump, fera sortir son pays de l’accord en mai 2018.
Entrechoquements axiologiques et sentiment de « frustration relative » : l’expression publique de la colère anti-médias des partisans de Donald J. Trump pendant la campagne présidentielle de 2016
Authors: Mort Sébastien
Published: February 2019

Depuis les campagnes présidentielles de 2016, l’hostilité envers les médias d’information grand public s’est très nettement intensifiée. Aiguillonnés par leur candidat, les partisans de Trump expriment publiquement leur colère envers les journalistes de ces médias, notamment en marge des rassemblements publics du candidat. En mobilisant les travaux sur le lien entre statut social et expression publique de la colère, la présente étude suggère que, dans le cas des partisans de Trump, l’impression de « frustration relative » (relative deprivation) par rapport à d’autres groupes sociaux préside à l’expression publique de la colère. L’influence des médias d’information sur la façon dont les soutiens de Trump évaluent leur « statut social subjectif » s’explique par les entrechoquements axiologiques entre ces derniers et les journalistes.
Expression d’un vécu traumatique par la médiation de l’outil vidéo chez des sujets « désamarrés »
Authors: Geoffroy-Romane Carol , Mazoyer Anne-Valérie
Published: February 2019

L’objet de cet article est de faire partager l’expérience d’une médiation corporelle et groupale, via l’outil vidéo, avec des sujets en grande précarité. La dynamique de groupe qui s’est instaurée a permis notamment à certains d’oser participer au tournage pour exprimer ensuite, hors caméra, des pans traumatiques de vie. Cet article tente d’analyser comment d’une part, le groupe fut un objet d’investissement pulsionnel et de représentations inconscientes (Pontalis, 1963), et d’autre part, combien le médium vidéo s’apparente aux effets structurants de l’expérience de la sensorialité originaire. À l’exemple de ce patient qui, dans l’après-coup d’une prise vidéo, prolonge l’entretien, donne à voir son corps en transparence, et révèle les déficits du sentiment d’existence.
Performances contrastées du développement des énergies renouvelables dans les régions françaises
Authors: Abdesselam Rafik , Renou-Maissant Patricia , Roussafi Ferdaous
Published: February 2019

La transition énergétique vers des énergies bas-carbone est aujourd’hui un paradigme dominant des politiques publiques liées à l’énergie. L’objectif de cet article est de proposer un état des lieux de la transition énergétique en France et plus précisément d’évaluer les performances des régions en matière de diversification du bouquet énergétique. Des méthodes d’analyse de données multidimensionnelles ont été employées. Une typologie des régions françaises caractéristique du développement régional des énergies renouvelables ( Enr ) en France en 2015 est proposée, elle met en évidence l’émergence de cinq profils types de développement des Enr très contrastés selon les filières d’ Enr . Un large éventail de variables dites « thématiques », constituées de variables environnementales, économiques, démographiques, géographiques, climatiques et politiques permet d’enrichir la caractérisation des classes de régions. Classification JEL  : C38, P18, P25, Q48, R11