bluuebunny/crossref_metadata_2025 huggingface dataset:
Toward a better understanding of in-field weed regulation by carabid beetles, and their functional characteristics, in European arable landscapes
Authors: Carbonne Benjamin , Bohan David , Petit Sandrine
Published: July 2019

For future arable agriculture, there is a need for more sustainable methods to manage weeds that are less reliant on herbicides and maintain food production. Control of weeds by natural enemies is an agro-ecological alternative to reduce the use of herbicides. While strong evidence points to carabid beetles exerting a regulatory effect on certain weed species, it is difficult to predict whether a particular assemblage of carabid species or functional groups will drive the function of weed seed predation in field conditions. There are also uncertainties about which key local and landscape-scale factors affect the function of weed seed predation, and the functional characteristics of carabid communities. In this presentation, we report on specific research actions being conducted within the wider C-IPM BioAWARE project that focuses on weed regulation by carabid biodiversity. We first briefly present statistical analyses aimed at identifying key assemblages of carabid taxa delivering high weed seed predation of Viola arvensis seeds during spring. We then present the principles and the implementation of the BioAWARE large-scale European survey currently in place. We explain how this large-scale design will be used to assess: (i) how landscape characteristics and infield trophic resources determine the functional characteristics and the diversity of carabid communities; and, (ii) key carabid assemblages delivering high seed predation of a large range of weeds through the evolution of the seedbank.
Mediterranean Ant Nest Beetles (Carabidae: Paussus): Out of Africa and Asia
Authors: Moore Wendy , Robertson James , Nagel Peter , Di Giulio Andrea
Published: July 2019

Endemic to the Palaeotropic and southern Palaearctic regions, ant nest beetles (Carabidae: Paussus) are specialized predators that depend on ants for their survival. This obligate relationship has driven extreme morphological adaptations that obscured our understanding of Paussus species relationships and subgeneric clades for centuries. Molecular phylogenetics has revealed patterns of relationship with high levels of convergence, and as a general rule, areas of endemism are better predictors of monophyly than overall morphology. For example, the species rich fauna of Madagascar is the product of one dispersal event from Africa approximately 2.6 million years ago, after which Malagasy ant nest beetles undertook one of the fastest species radiations ever documented within animals. With their center of diversity in sub-Saharan Africa, the Paussus fauna of the Mediterranean is relatively depauperate with only seven species described from north of the Sahara. Pre-molecular subgeneric classifications, which were based on overall morphology, suggest that these seven species represent five species group lineages. Here, we use molecular sequence data from five genes and a taxon-sampling strategy aimed at investigating the biogeographic origins of five Mediterranean species. We find that the present-day Mediterranean fauna, unlike that of Madagascar, is the result of five separate dispersal events, four from the Afrotropical Region and one from the Indomalayan Region. Implications of associated host ant shifts are also explored.
Molecular Phylogeny and Tribal Classification of Flanged Bombardier Beetles (Carabidae: Paussinae)
Authors: Moore Wendy , Maddison David
Published: July 2019

Members of the carabid subfamily Paussinae are known for their explosive defensive chemistry and their associations with ants, which vary from some species being facultative predators of adult ants to others being obligate predators of ant brood. This association with ants has driven extreme morphological adaptations in some lineages. Approximately 750 species are currently classified into four tribes: Metriini, Ozaenini, Protopaussini and Paussini. Here we use molecular sequence data from five genes (28S ribosomal DNA; 18S ribosomal DNA; wingless; carbamoyl phosphate synthetase domain of the rudimentary gene; and arginine kinase) to reveal patterns of deep divergence and provide a new tribal level classification reflecting evolutionary history. We recognize and describe two new tribes, and the tribe Ozaenini is redefined. Among other traits, members of each tribe has a characteristic shape of the cuticular fold at the posterolateral angle of both elytra, known as the flange of Coanda.
Contact rates with nesting birds before and after invasive snake removal: estimating the effects of trap-based control
Authors: Yackel Adams Amy A. , Nafus Melia G. , Klug Page E. , Lardner Björn , Mazurek M. J. , Savidge Julie A. , Reed Robert N.
Published: July 2019

Invasive predators are responsible for almost 60% of all vertebrate extinctions worldwide with the most vulnerable faunas occurring on islands. The brown treesnake (Boigairregularis) is a notorious invasive predator that caused the extirpation or extinction of most native forest birds on Guam. The success of avian reintroduction efforts on Guam will depend on whether snake-control techniques sufficiently reduce contact rates between brown treesnakes and reintroduced birds. Mouse-lure traps can successfully reduce brown treesnake populations at local scales. Over a 22-week period both with and without active snake removal, we evaluated snake-trap contact rates for mouse- and bird-lure traps. Bird-lure traps served as a proxy for reintroduced nesting birds. Overall, mouse-lure traps caught more snakes per trap night than did bird-lure traps. However, cameras revealed that bird-lure traps had a snake contact rate almost 15 times greater than the number of successfully captured snakes. Snakes that entered bird-lure traps tended to be larger and in better body condition and were mostly captured in bird-lure traps, despite numerous adjacent mouse-lure traps. Traps placed along grid edges caught more snakes than interior traps, suggesting continuous immigration into the trapping grid within which bird-lure traps were located. Contact between snakes and bird-lure traps was equivalent before and after snake removal, suggesting mouse-lure traps did not adequately reduce the density of snakes that posed a risk to birds, at least at the timescale of this project. This study provides evidence that some snakes exhibit prey selectivity for live birds over live mouse lures. Reliance on a single control tool and lure may be inadequate for support of avian reintroductions and could lead to unintended harvest-driven trait changes of this invasive predator.
Environmental factors affecting the success of exotic plant invasion in a wildland-urban ecotone in temperate South America
Authors: Nievas Romina Paola , Calderon Mirian Roxana , Moglia Marta Matilde
Published: July 2019

Urbanization is one of the main causes driving changes in biodiversity patterns and it is regarded as a major threat to native biota. Successful exotic plant invasion depends on invasiveness and invasibility. Invasiveness is related to the characteristics of exotic plants and invasibility to the features of the sites. The objective of this study was to identify the invasibility environmental factors affecting the success of exotic plant invasion in a wildland-urban ecotone of the central region of Argentina (Potrero de los Funes Village, San Luis). Fifty phytosociological inventories were recorded in an area of 700 ha during spring and summer seasons (2013–2015). Abundance-coverage values of plants and environmental variables such as soil characteristics, anthropogenic disturbance, and altitude of the sites were assessed. Soil moisture, electrical conductivity (EC), acidity (pH), organic matter content, and nitrates were determined as part of the soil analysis. A Nonmetric Multidimensional Scaling analysis was used to identify the possible relationship between abundance-coverage of the vegetation and environmental variables. Abundance-coverage of exotic plants was positively influenced by anthropogenic disturbance and nitrate levels, and negatively affected by altitude. However, no significant correlation was found between percentage of exotic plants and pH, EC, or soil moisture. Thus, urbanization and touristic activities influenced the success of exotic plant invasion.
A molecular study of Neophyllaphis varicolor (Hemiptera, Aphididae) in Costa Rica
Authors: Zúñiga-Centeno Adonay , Sandoval-Carvajal Izayana , Montero-Astúa Mauricio , Villalobos-Muller William , Quốc Nguyễn Bảo , Pérez Hidalgo Nicolás
Published: July 2019

The genusNeophyllaphis(Takahashi) (Aphididae: Neophyllaphidinae) is composed of 18 species; however, in the Americas only nine species have been reported previously. A new species,NeophyllaphisvaricolorMiller & Halbert, was described in 2014 in USA. Colonies resembling those of this new species have been observed in Costa Rica onPodocarpusspp. In order to determine ifN.varicoloris also present in Costa Rica, we sampledNeophyllaphiscolonies fromPodocarpusfalcatusandP.chinensis. Additionally, we sampled individuals fromPodocarpussp. in Spain and Vietnam. DNA of each sample was extracted and used to amplify and sequence the cytochromecoxidase subunit I (COI) and elongation factor I (EF-1α) partial regions. According to morphological characteristics, sequences comparisons done in GenBank and BOLD, and phylogenetic analyses, the colonies collected fromPodocarpusspp. in Costa Rica and the colony from Vietnam corresponded to the speciesN.varicolor. To the best of our knowledge this is the first report of the presence ofN.varicolorin Central America and Vietnam.
New insights in Trichochloritis Pilsbry, 1891 and its relatives (Gastropoda, Pulmonata, Camaenidae)
Authors: Páll-Gergely Barna , Neubert Eike
Published: July 2019

The genusBellatrachiaSchileyko, 2018 was described based on a specimen identified as Helix (Chloritis) pseudomiara Bavay & Dautzenberg, 1909. We concluded that the examined specimen is not that species, butHelixcondorianaCrosse & Fischer, 1863. Therefore, (1) the type species ofBellatrachiamust be replaced withHelixcondoriana; (2) the species Helix (Chloritis) pseudomiara must be re-allocated to the genusTrichochloritis; (3) the erroneous treatment of the genusTrichochloritisby Schileyko (2007) needs to be corrected through the description of a new genus,Dentichloritisgen.nov.based onHelixbrevidensSowerby I, 1841. In addition,ChloritismicrotrichaMöllendorff, 1898 is treated as a synonym ofHelixcondoriana, and further information on the genitalia ofChloritis(?)bifoveata(Benson, 1856) is presented.
Co-Deposition and Characterization of Hydroxyapatite-Chitosan and Hydroxyapatite-Polyvinylacetate Coatings on 304 SS for Biomedical Devices
Authors: Zanca Claudio , Mendolia Isabella , Capuana Elisa , Blanda Giuseppe , Carfì Pavia Francesco , Brucato Valerio , Ghersi Giulio , la Carrubba Vincenzo , Piazza Salvatore , Sunseri Carmelo , Inguanta Rosalinda
Published: July 2019

During the last decades, biomaterials have been deeply studied to perform and improve coatings for biomedical devices. Metallic materials, especially in the orthopedic field, represent the most common material used for different type of devices thanks to their good mechanical properties. Nevertheless, low/medium resistance to corrosion and low osteointegration ability characterizes these materials. To overcome these problems, the use of biocoatings on metals substrate is largely diffused. In fact, biocoatings have a key role to confer biocompatibility properties, to inhibit corrosion and thus improve the lifetime of implanted devices. In this work, the attention was focused on Hydroxyapatite-Chitosan (HA/CS) and Hydroxyapatite-Polyvinylacetate (HA/PVAc) composites, that have been studied as biocoatings for 304 SS based devices. Hydroxyapatite was selected for its osteoconductivity thanks to its chemical structure similar to bones. Furthermore, Chitosan and Polyvinylacetate are largely used yet in medical field (e.g. antibacterial agent or drug deliver) and in this work were used to create a synergic interaction with hydroxyapatite to increase the strength and bioactivity of coating. Biocotings were obtained by galvanic deposition process that does not require an external power supply. It is a spontaneous electrochemical deposition in which materials with different standard electrochemical potential were short-circuited and immersed in an electrolytic solution. Electrons supply for the cathodic reaction in the noblest material comes from oxidation of the less noble material. SEM, EDS, XRD and RAMAN were performed for chemical-physics characterization of biocoatings. Polarization and impedance measurements have been carried out to evaluate corrosion behavior. Besides, in-vitro cytotoxicity assays have been done for the biological features.
Mechanical and Functional Properties of Cavitation Generators with PVD Functional Coatings Intended for Use in the Cavitation Environment
Authors: Borek Wojciech , Linek Tomasz , Tański Tomasz , Pancielejko Mieczysław , Staszuk Marcin
Published: July 2019

The main purpose of this publication was to describe in details the correlation between microhardness and scratch test results of the tested coatings deposited by PVD (Physical Vapour Deposition) method on the cavitation generators working in cavitation environment. First coating in the form of composite layer CrN+WC/C and second WC/C plate coating were deposited on two selected steels which already are used or can be use on constructional elements working in a cavitation wear environment. Steel P265GH is commonly used for pressure devices working at elevated temperatures, with a ferritic – pearlitic structure, and the other tested steel from a group of stainless steels, i.e. chromium – nickel X2CrNi18-9 (304L) steel with an austenitic structure due to its corrosion resistance, it can also be used in these conditions. The tests results obtained allow to conclude composite CrN+WC/C coating exhibit better adhesion than WC/C plate coatings deposited on the both tested constructional steels. A critical load value for the CrN+WC/C coating spans between 29 and 34N and is 35-40% higher than for the plate WC/C coating.
Forming Process during Electron Beam Surfi-SculptTM on Ti-6Al-4V Alloy
Authors: Li Kai , Fu Peng Fei , Tang Zhen Yun , Zhang Bo , Ma Yan Long , Li Wen , Jin Lei , Dun Yu Chao
Published: July 2019

Electron beam Surfi-SculptTM is a novel surface treatment technique applied to produce high level performance Composite-Metal-Weld (ComeldTM) joints. Investigation on forming process during electron beam Surfi-SculptTM on Ti-6Al-4V alloy showed protrusions were formed via a layer-by-layer mode like additive manufacturing process. The near-surface region of electron beam Surfi-Sculpted Ti-6Al-4V alloy was occupied by fusion zone, heat-affected zone and base metal from the outermost surface to the underlying bulk alloy. The microstructure of fusion zone was characterized by a high density of fine acicular martensite phase, leading to a higher micro-hardness. A heat-affected zone was sandwiched between fusion zone and the underlying base metal, with different microstructural features compared to both fusion zone and the base metal.
Morphological and Chemical Characterization of Laser Treated Surface on Copper
Authors: Baudin Lucie , Sitko Monika , Garion Cédric , Chiggiato Paolo , Delloro Francesco , Gaslain Fabrice , Sennour Mohamed , Jeandin Michel , Bajek David , Wackerow Stefan , Abdolvand Amin
Published: July 2019

Electron multipacting and electron cloud have been identified as being the major limiting factors for the beam quality or for the cryogenic system of high-intensity positive particles accelerators. Among conditioning operational techniques and other surface structuration techniques used to decrease the Secondary Electron Yield (SEY) of surfaces, laser surface treatment is a promising method to treat in situ and at atmospheric pressure copper surface of the vacuum chamber. Here, pulsed laser irradiation of copper in parallel lines pattern led to the local ablation and deposition of aggregates of copper particulates on the surface. Tests undertaken at CERN have shown that the modification of the surface morphology by creating roughness at different scales induces a decrease of the SEY by geometrical effects. Nevertheless, the mechanical strength and dust generation of the treated surface have not been addressed yet.In this work, a qualitative analysis of the multi-scale description of the surface morphology was carried out. Scanning Electron Microscopy (SEM), Focused Ion Beam (FIB), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectroscopy (EDS) were used to investigate morphological characterization such as size and shape of the particulates, chemical composition, metallographic structures and phase transformation on the laser-processed surface.SEM and FIB examinations showed that the surface morphology depends on the local laser energy irradiating the surface and especially, relatively to the ablation threshold. TEM analysis revealed chemical composition and crystalline configuration of the treated material and helped to identify the laser modified and oxidized areas. A variety of superficial structures were observed. Potential vulnerable structures have been identified as oxidized matter redeposited on the ablated near surface. Material continuity and composition play a major role in the mechanical integrity of the generated surface morphology. The adherence of the created structures was assessed analyzing the origin of the dust extracted after mechanical stress.
Microstructure and Corrosion Properties of PEO Coatings Produced on AM-Aluminum Alloys
Authors: Pezzato Luca , Dabalà Manuele , Brunelli Katya
Published: July 2019

Aluminum alloys are one of the main materials employed in aerospace and automotive applications. One of the problems that affect these alloys in certain application is the poor corrosion resistance that can, however, be enhanced with proper surface treatments, such as anodizing. Among these treatments, Plasma Electrolytic Oxidation (PEO) is one of the most promising and the production of PEO coatings on traditional aluminum alloy was extensively studied in literature. Recently, the production of a lot of components is going into the direction of using innovative manufacturing systems and customized components, with improved mechanical and physical properties, can be manufactured by additive manufacturing (AM) techniques. Among the AM methods, laser-based AM has an immense potential for producing fully dense metallic structures, using a variety of available metal powders and has attracted more and more attention. The resulting AM samples are characterized by different microstructures in comparison with the conventionally manufactured ones and this can cause differences also in the production of PEO coatings and other surface treatments. Objective of the present work is to produce PEO coatings on AM samples in order to increase the corrosion and wear performances of the samples. PEO coating were produced on the samples testing different parameters and the coatings were characterized, in terms of microstructure and composition, with SEM analysis. The corrosion resistance of the samples was also evaluated with electrochemical tests. The results were compared with the ones obtained on traditionally manufactured samples. PEO coatings were successfully produced on AM samples obtaining samples with good coatings thickness and improved corrosion performances compared to the untreated ones.
The Impact of Formation of Oxide Layer on the Piston Crown Using Micro - Arc Oxidation on the Characteristics of the Spark Ignition Engine
Authors: Velavan A. , Saravanan C.G. , Vikneswaran M.
Published: July 2019

In the present study, experiments were conducted to compare the effect of oxide layer formation on the piston crown coated using Micro-Arc Oxidation (MAO) with uncoated piston on the combustion and emission characteristics of the port injected Spark Ignition engine fueled by gasoline. The micro-arc oxidation (MAO) coating technique is the modern process to form a ceramic oxide layer on the reactive metal substrate (base metal) by electrochemical and electro-thermal oxidation in an alkaline electrolytic solution. Using MAO technique, an oxide layer of thickness 72 μm was formed on the piston crown. This oxide layer acts as a thermal barrier to reduce the in-cylinder heat rejection and increase the durability of the piston by withstanding high temperature and pressure produced during combustion. Combustion flames have been captured using the AVL combustion analyzer to analyze the development and propagation of flames within the engine cylinder. From the flame images, it was observed that propagation of flame was faster in MAO coated piston compared to uncoated piston. This is because of higher local temperature inside the combustion chamber that was resulted due to low thermal conductivity of MAO layer. It was also found that carbon monoxide (CO) and hydrocarbon (HC) emissions were reduced as a result of efficient fuel combustion, while NOx emissions increased because of increased combustion temperatures for MAO coated pistons. Keywords: Electro-thermal oxidation, Flame propagation, Micro-arc oxidation, Piston crown, Thermal barrie
Increasing of ENF Bonded Joints Performance by Design of Laser Surface Texturing
Authors: Sorrentino Luca , Bellini Costanzo , Parodo Gianluca , Turchetta Sandro
Published: July 2019

In the last decades, structural adhesives have found an increasing use owing to the fact that they, compared to traditional techniques like bolting and riveting, allow more uniform stress in the joint without drilling the parts of the assembly. Moreover, the quality of a bonded joint is strongly linked to the surface treatment used for the adherends. Recently, many studies showed the opportunity to use a CO2 laser for enhancing the mechanical properties of bonded joints in FRP. Nowadays, to optimize their process parameters and texturing represent a necessary step for the growth in this technology. In this work, a numerical study of the effect of laser texturing on end notched flexure (ENF) joints realized in CFRP has been developed. In particular, it is possible to design of the laser texturing for optimizing the mechanical response of bonded joints.
Effect of Carbon Nanotubes Dispersion on the Microhardness of CFRP Composites
Authors: Forcellese Archimede , Nardinocchi Alessia , Simoncini Michela , Vita Alessio
Published: July 2019

The present investigation aims at studying the effect of carbon nanotubes dispersion on the surface hardness of carbon fiber-reinforced polymer composites, manufactured by means of compression resin transfer molding. The influence of the weight fraction of nanofiller, distributed in the epoxy matrix, on the Vickers hardness values was investigated. Furthermore, the evaluation of carbon nanotubes filtering effect was also taken into account by comparing the hardness values measured at the top and bottom surfaces of the laminate composites. It was observed that the different weight loads affect the surface properties of the nano-composites, both in terms of hardness and filtering effect.
Evaluation of Tribological Properties of Hard Coatings Obtained on Steel C45 by Electro-Spark Alloying
Authors: Kukareko Vladimir , Agafii Vasile , Mihailov Valentin , Grigorchic Aleksandr , Kazak Natalia
Published: July 2019

It was shown that under dry contact conditions, under normal load of to 2 MPa, all coatings demonstrated a significant increase in wear resistance compared to that of the substrate. However, among them, the Mo coating showed the highest wear resistance: ~20 times higher than that of the uncoated steel. That was caused not only by the Mo high microhardness and the lowest initial roughness, but also by the structure of this coating. Meanwhile, the Ti + SiC samples displayed the highest microhardness among investigated coatings. A correlation was established between the microhardness of the coating and the friction coefficient: the larger the microhardness of the coating, the higher is the coefficient of friction. An X-ray analysis of the coatings obtained by ESA on steel with compositions (Ti + Al + C), (Ti + AlN) and (Ti + SiC) revealed phases of titanium carbide, titanium nitride, intermetallic compound AlFe3, and small amounts of aluminum nitride, silicon dioxide and titanium dioxide. This could explain the high microhardness (from 6.8 up to 13.8 GPa) of the obtained coatings.
Impact Wear Resistance of Nanocomposite Coatings for Aircraft Components
Authors: Gautier Giovanna , Faga Maria Giulia , Tebaldo Vincenzo
Published: July 2019

Landing gear is an aircraft component often subjected to wear, fracture, mechanical failure and erosion, principally caused by impact with sand and other small particles. Erosion wear can cause deformation and material removal with consequent efficiency reduction. Coatings can protect stressed structural part and impede the erosion of the metallic components. This work focus on the investigation of the erosion resistance of two ceramic multilayer coatings, AlSiTiN and AlSiCrN, deposited by Physical Vapour Deposition (PVD) on a high speed steel (H11) usually used for landing gear application. Erosion test were carried out with an erosion machine using alumina particles. Powder was directed to the specimens (coatings and substrate) at nominal impingement angles of 90° and 20° with different impact speed (50, 75, 100 and 125 m/s at 90° and 100, 125, 150 and 175 m/s at 20°), at a nozzle-specimen distance of 10 mm. All the tests were performed for two minutes. Hardness and Young's modulus were obtained by nanoindentation, and adhesion between coating and substrate was evaluated by scratch test. Volume lost was measured with Taylor Hobson profiler while cracking behaviour and microstructure modifications were examined with a scanning electron microscope (SEM). AlSiCrN coating significantly enhanced the erosion resistance of H11 substrate, showing higher resistance also with respect to AlSiTiN coating. Indeed, the coating was not completely removed from the surface neither at 90° nor at 20°. The erosion wear rapidly increased by increasing the impact speed in the case of substrate and AlSiTiN, while such parameter was not significantly influent in the case of AlSiCrN. The results suggest that adhesion should play an important role to explain the highest erosion resistance of AlSiCrN coating. Erosion mechanism was principally driven by the intrinsic brittleness of both ceramic coatings.
Surface Induction Hardening of Steels: Process Modelling and Numerical Simulation
Authors: Tucci Fausto , Esperto Vitantonio , Felice Rubino , Carlone Pierpaolo
Published: July 2019

Heat treatments are widely used in industry to improve the surface behavior of components exposed to external mechanical actions and, therefore, undergoing wear phenomena. If compared to the conventional thermal treatments, induction hardening is an interesting candidate solution when the effect should be limited to the surface without affecting the microstructure and properties at the material core. Furthermore, this solution is appealing considering energy saving and cost reduction. In this process, an intense electric alternating current flows through a conductive coil enveloping the component to be treated. Such current generates a magnetic field and, as a consequence, eddy currents arise in the conductive work-piece providing a heat generation by the Joule effect. Due to this mechanism, the induction heating is characterized by faster heating rates with respect to the heating in a hot furnace. On the other hand, the induction hardening process requires a more challenging control of the operative parameters, namely the current density and frequency and the coil advancing speed. Numerical modeling and simulation are recognized as a very useful tool to predicting the effects induced by a treatment, avoiding undesired insufficient- or over-heating. The present work deals with a finite element numerical approach to the simulation of an induction hardening treatment of a steel component. The model is based on the subsequent solution of two numerical submodels. Firstly, the electro-magnetic field generated by the current flowing through a coil surrounding the processing part is inferred solving the Maxwell governing equations. Then, the magnetic field is used as input load for the subsequent heat transfer transient finite element model. The influence of the current density and frequency as well as other processing parameters on the magnetic and thermal fields is discussed.
Multi-Layer Cold Spray Coating: Strain Distribution
Authors: Marzbanrad Bahareh , Toyserkani Ehsan , Jahed Hamid
Published: July 2019

In this paper, we report the effect of multi-layer cold spray deposition on the residual stress formation in the coating and substrate. A method is proposed to separately measure the thermal and mechanical residual stresses induced in cold spray coating. Fiber Bragg Grating (FBG) sensors were employed for in situ monitoring of the strain evolution during the cold spray of multi-layer coating Al7075-Zn on AZ31B Magnesium substrates. Utilizing the capability of the FBG sensors in recording both thermal and mechanical strain gradients, first the effect of temperature on the substrate was investigated when the sample was only treated under carrier gas temperature. Then, the sensors were employed to evaluate the mechanical strain behavior of substrate during the coating process and cooling. Therefore, the effect of thermal mismatch on inducing mechanical strains was observable during the process. Finally, the interaction between the peening process of cold spray and thermal mismatch after cooling was studied. It is shown that the thermal expansion coefficient (CTE) plays a critical role in residual stress development in the substrate and consequently affects the mechanical properties of the coated sample. Hence, careful selection of layers in multilayer deposition can provide desired residual stress in the coating and substrate.
Effect of Plasma Surface Treatment on the Impact Behavior of Basalt/Epoxy Composites
Authors: Ricciardi Maria Rosaria , Papa Ilaria , Coppola Giuseppe , Impero Filomena , Lopresto Valentina , Sansone Lucia , Antonucci Vincenza
Published: July 2019

In this study, the effects of surface treatment of a low-temperature atmospheric oxygen plasma on basalt/epoxy composites were investigated to improve the hydrophobility of the composite surface. After the plasma treatment, the unmodified and surface treated composite laminates have been experimentally characterized by performing contact angle measurements, low-velocity impact tests and indentation depth on the impacted laminates. Results have showed a dependence of such composite properties on the plasma coating deposition and on the treatment parameters outlining the need to optimize both the plasma power and exposition time to plasma in order to assess the efficiency of the plasma treatment and establish the optimal processing conditions.
Tribological Behavior of a Polyester Composite System under Severe Wear Conditions
Authors: Durante Massimo , Boccarusso Luca , Minutolo Fabrizio Memola Capece , Paradiso Pier Paolo , Marlia Marco , Villani Giuseppe , Batistoni Nicola
Published: July 2019

This work aims on the study of the wear resistance of a commercial polyester composite system under severe wear conditions. It is an example of composite engineering material manufactured from synthetic fibers and thermosetting resins with appealing physical and mechanical properties that make it very interesting for products like sheets, rods, tubes, flange, washers and wear ring. In order to make it suitable for applications where damage by metal roll surfaces can occur, the study of the wear behavior under specific conditions is then necessary. At this aim, a detailed experimental campaign, including tribological tests and microgeometrical measurements, was carried out. In particular, the tribological behaviour was studied through the pin-on-disk tests conducted at 209 mm/s as peripheral speed under an applied load comprising in the range of 10 - 70 N. The tests were followed by microgeometrical measurements by using a confocal microscope in order to critically observe the wear tracks, evaluate their depth, width and then to calculate the final less of volume. The results proved that the wear mechanisms founded for the composite under investigation differ from those commonly associated to metals; the surface asperities of the fibres allow to hold the lubricant inside the surface and thus assist in the maintenance of a continuous film on the working surface involving in very low friction coefficient.
Cold Spray Technology to Promote Conductivity of Short Carbon Fiber Reinforced Polyether-Ether-Ketone (PEEK)
Authors: Lomonaco Patrizio , Weiller Sebastien , Feki Imen , Debray Antoine , Delloro Francesco , Jeandin Michel , Favini Bernardo , Rossignol Claude
Published: July 2019

Recent studies showed that cold spray is a suitable way to produce metallic coatings on non-metallic surfaces such as polymers and composites for engineering applications. Mechanical bonding and particle anchoring process onto these substrates have not been totally understood yet. This study is focused on the creation of conductive coatings by cold spray onto short carbon fiber reinforced PEEK. For the requirements of the industrial application, the deposit should be able to tolerate both electrostatic and electric currents (higher than 10A). Because of their high conductivity, aluminium and copper powder seemed to be the best candidate materials. To promote adhesion and coating build up, copper-zinc and copper-PEEK mixed powders were also tested. A correlation between experimental and numerical tests has been adopted to assess and improve the possibilities of this material coupling. Both low pressure and high-pressure cold spray equipment were used for the spraying. Since polymer matrix-based composites are thermosensitive materials, it was necessary to develop a computational fluid-dynamics tool to investigate the interaction of the hot gas on the substrate and the correlation with the deposition process. A series of finite element simulations of single and multi-particle impacts onto local structures of the composite, as observed from SEM images of the specimens, is on-going. A classical pull-off test of the specimen will be adopted to collect data about coating adhesion strength. Finally, the four points measurement by Van der Pauw method will be used to assess the conductivity of specimens for different powders and coating thicknesses.
Experimental Study of Laser Texturing Processes on the Lubricant Retention of Carbide (WC-Co) Surfaces
Authors: Vázquez-Martínez Juan Manuel , Del Sol Irene , Batista Moises , Fernández-Vidal Severo Raúl , Hernandez Pedro M. , Salguero Jorge
Published: July 2019

Machining process usually involves relevant wear effects on the cutting tool, producing undesirable surface features on the work-pieces. Lubricants and cooling fluids are used with the aim to minimize the wear phenomena as well as high temperatures produced during the cutting processes. However, the use of these fluids may have an adverse environmental impact. For this reason, the reduction of quantity of cutting fluids used in the machining process is a requirement in order to improve the performance and sustainability of the process. For this purpose, this work proposes an increase of the lubricant retention ability for cutting tools based on surface modification. In this research, micro-geometrical features of Carbide (WC-Co) surfaces have been modified by laser texturing techniques. A wide range of roughness topographies had been developed by changing the laser irradiation parameters of energy density of pulse (Ed) and scanning speed of the beam (Vs). Different geometries of the textured tracks (single spots, linear tracks, circular tracks) also were studied. Moreover, through specific roughness features conducted by texturing process, the retention ability of cutting fluids was modified. It was evaluated by the contact angle between liquid and solid phases. This modification allowed to increase the self-lubricant effect of the WC-Co surface. This methodology has been validated on carbide tools under lubricated machining processes. Wear effects on the cutting tool were reduced and the surface finish of the machined parts was remained at least in the same ranges as non-modified tools.
Electrochemical Characterization of Ti6Al4V Components Produced by Additive Manufacturing
Authors: Acquesta Annalisa , Carangelo Anna , Di Petta Paolo , Monetta Tullio
Published: July 2019

The investigation of the corrosion resistance of Ti6Al4V alloy components produced by additive technology is still lacking in the literature. This paper aims to study the electrochemical behaviour of Ti6Al4V components fabricated by laser powder-bed fusion additive manufacturing process. The metallographic analysis was carried out by an optical microscope. The electrochemical behaviour has been evaluated in 3.5 wt. % of natural aerated NaCl aqueous solution by potentiodynamic polarization test. The results have been compared to a conventionally manufactured Ti6Al4V component. The typical martensitic structure has been shown by the additive manufactured sample. As expected, the metallographic analysis revealed a martensitic microstructure. The electrochemical tests carried out on the surface of the as-received additive manufactured specimen showed an influence of its morphology on the values of passive current density, higher than that recorded for the conventionally manufactured sample, used as the control. After mechanical polishing, the electrochemical tests were repeated on the "bulk" of the samples. The open circuit potential values were higher than the value recorded for the conventionally manufactured sample. The conditions of the additive process affect the corrosion resistance of the components due to the roughness of the surface and to the microstructure created.
Nutritional quality, safety and sensory properties of smoked tench (Tinca tinca) pâté from Trasimeno Lake, Italy
Authors: Branciari Raffaella , Roila Rossana , Valiani Andrea , Ranucci David , Ortenzi Roberta , Miraglia Dino , Bailetti Lucia , Franceschini Raffaella
Published: July 2019

The present study evaluated the safety, nutritional and sensory properties of fish pâtés made from smoked tench (Tinca tinca) pulp. Two formulations of tench pâté were produced, one of which included olive oil and the other contained mascarpone cheese. The prepared pâté jars were thermally treated according to the method applied in the canning industry. The inactivation of Clostridium botulinum during thermal treatment was determined through a challenge test study, demonstrating the complete depletion of targeted bacteria. Tench pâtés showed high nutritional properties, especially the formulation with olive oil, which was characterised by lower contents of cholesterol and saturated fatty acids and a high level of monounsaturated fatty acids. The two experimental formulations possessed a specific sensory profile, due to the ingredients incorporated into the products. Consumers’ evaluation established differences in the acceptance of the two products: the formulation with added olive oil was more appreciated by consumers, who displayed a higher purchase intent for this product. The study suggests that minced smoked tench is not only a promising ingredient for pâté production but that it also represents a value-added product able to contribute to freshwater food consumption.
Prolonged static muscle stretch reduces spasticity - But for how long should it be held?
Authors: Hale L. A. , Fritz V. U. , Goodman M.
Published: July 2019

The rehabilitation of patients with upper motor neurone lesions often necessitates the reduction of spasticity before normal movement patterns can be taught. One proven technique is that of prolonged stretch to the affected muscle. However, the duration of the stretch has not been defined. This study aimed to investigate which of the following durations of prolonged muscle stretch - two, ten or thirty minutes - was optimal in reducing spasticity in spastic quadriceps femoris muscles of adult patients following cerebral vascular accidents or head trauma. The degree of spasticity was measured by the use of four methods, prior to, and after stretching. Twenty-nine spastic muscles were stretched for the three durations on different occasions, and the data analysed using the student's T-test.Results indicated that the most beneficial duration of prolonged muscle stretch in decreasing spasticity was ten minutes.
The Role of School in the Management of Children with Epilepsy
Authors: Abdullahi Aminu Taura , Taura Umar Abdullahi , Farouk Zubaida Ladan
Published: July 2019

Worldwide, epilepsy affects about 0.7% of children of school age. It is associated with educational difficulties in addition to psychological, social, and other comorbidities. It is important for children with medical conditions such as epilepsy to receive education. The trend is to provide this at mainstream schools. However, there is poor perception and lack of support for children with epilepsy from schoolteachers and the school environment, especially in low and middle-income countries. Teachers, healthcare providers, and policymakers need to have a good understanding of the various issues involved in providing education to these children. We therefore carry out a review of the literature with the aim of highlighting the keys issues pertaining to the education of children with epilepsy. We conclude that the school environment has a role in the management of children with epilepsy from the diagnosis, psychosocial support, and control of stigma to seizure treatment. In particular, there is a need for teachers to be involved in the management of these children in the school environment. Specifically, the involvement of teachers in the provision of rescue medication and safety measures needs to be emphasized.
Constructed wetlands as post treatment of a decanter digester followed by an anaerobic filter
Authors: Reis Wilhan Douglas , Santos Aldecy De Almeida , Oliveira Eduarda Da Conceição , Ito João Batista
Published: July 2019

The amount of wastewater has increased due to the considerable expansion of higher education institutions. When wastewater is released without treatment or with inefficient treatment, it causes significant water pollution. In this context, this study evaluated the performance of Constructed Wetlands as a post-treatment of a decanter digester followed by an anaerobic filter, operated with effluent from the Federal University of Mato Grosso, Cuiabá Campus, Mato Grosso State.  Four wetlands were constructed to develop the research: planted with Typha domingensis, planted with Heliconia psittacorum, planted with Pontederia parviflora, and not planted. The following physicochemical parameters were analyzed:  Color, Turbidity, pH, Temperature, Total Solids, Total Dissolved Solids (TDS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Nitrogen, Sulfate, Nitrate and Nitrite. The results show an organic matter removal efficiency with mean removal results: 70% BOD5 for TCW, HCW and PCW; and COD 76% for PCW. The mean removal of total phosphorus was 78% for PCW and 92% NO-2, as macronutrients. Analysis of variance ANOVA shows significance in the results of TDS, SO4 and COD removal.
On Homogeneous Polynomials Determined by their Partial Derivatives
Authors: Wang Zhenjian
Published: July 2019

We prove that a generic homogeneous polynomial of degree $d$ is determined, up to a nonzero constant multiplicative factor, by the vector space spanned by its partial derivatives of order $k$ for $k\leqslant \frac{d}{2}-1$.
Semi-martingale decomposition and heat kernel estimates of reflected stable-like processes with variable order
Authors: Shin Jiyong
Published: July 2019

Мы изучаем отраженные симметричные процессы устойчивого типа (на компактном множестве $\overline{E}\subset\mathbf{R}^d$), ассоциированные с нелокальными формами Дирихле, в случае переменного порядка $\alpha{( \cdot ,\cdot )}$ в ядре интенсивности скачков. Сначала, предполагая выполненными двусторонние оценки непрерывной переходной плотности отраженного процесса устойчивого типа $(X_t)_{t \ge 0}$, мы получаем, аналогично [10], семимартингальное разложение процесса $(X_t)_{t \ge 0}$. Затем, при некоторых дополнительных условиях на $\alpha{( \cdot ,\cdot )}$, мы выводим в явном виде верхние и нижние оценки для непрерывной по Гeльдеру переходной плотности процесса $(X_t)_{t \ge 0}$.
Berry-Esseen bounds and ASCLTs for drift parameter estimator of mixed fractional Ornstein-Uhlenbeck process with discrete observations
Authors: Alazemi Fares , Douissi Soukaina , Es-Sebaiy Khalifa
Published: July 2019

Рассматривается задача оценивания сноса смешанного процесса Орнштейна-Уленбека на основе наблюдений в фиксированные дискретные моменты времени. С использованием исчисления Маллявена и недавнего анализа Нурдина-Пеккати исследуется асимптотическое поведение оценки. Более точно, изучаются сильная состоятельность и асимптотическое распределение оценки; установлена также скорость ее сходимости по распределению для всех $H\in(0,1)$. Более того, доказано, что в случае $H\in(0,3/4]$ оценка удовлетворяет центральной предельной теореме для сходимости почти наверное.
Оценка коэффициента загрузки для многоканальной системы обслуживания с регенерирующим входящим потоком
Authors: Krylova Galina Aleksandrovna
Published: July 2019

Рассматривается многоканальная система обслуживания с регенерирующим входящим потоком Reg/G/m в условиях существования предельного режима. В статье предложена статистическая оценка коэффициента загрузки системы и доказана ее состоятельность.
Human rights principles in the WIPO Marrakesh Treaty: driving change in copyright law from within
Authors: Ayoubi Lida
Published: July 2019

The number of countries joining the WIPO Marrakesh Treaty for the visually impaired has been gradually increasing since its adoption in 2013. This article evaluates the contribution of the WIPO Marrakesh Treaty to the untangling and understanding of the interface of intellectual property law and human rights law. It analyses the significance of the human rights language used in the Treaty as well as its mandatory copyright exceptions. It is argued that the significance of the Treaty mainly lies in its inclusion of human rights principles. This, together with the introduction of compulsory copyright limitations and exceptions, forms the innovative approach of the Treaty that reshapes the contours of the relationship between intellectual property rights and human rights.
A geometry-dependent surface Lambertian-equivalent reflectivity product for UV/Vis retrievals: Part II. Evaluation over open ocean
Authors: Fasnacht Zachary , Vasilkov Alexander , Haffner David , Qin Wenhan , Joiner Joanna , Krotkov Nickolay , Sayer Andrew M. , Spurr Robert
Published: July 2019

Abstract. Satellite-based cloud, aerosol, and trace gas retrievals from ultraviolet (UV) and visible (Vis) wavelengths depend on the accurate representation of surface reflectivity. Current UV and Vis retrieval algorithms typically use surface reflectivity climatologies that do not account for variation in satellite viewing geometry or surface roughness. The concept of geometry-dependent surface Lambertian-equivalent reflectivity (GLER) is implemented for water surfaces to account for surface anisotropy using a Case 1 water optical model and the Cox-Munk slope distribution for ocean surface roughness. GLER is compared with Lambertian-Equivalent reflectivity (LER) derived from the Ozone Monitoring Instrument (OMI) for clear scenes at 354, 388, 440, and 466 nm. We show that GLER compares well with the measured LER data over the open ocean and captures the directionality effects not accounted for in climatological LER databases. Small biases are seen when GLER and the OMI-derived LER are compared. GLER is biased low by up to 0.01–0.02 at Vis wavelengths, and biased high by around 0.01 in the UV, particularly at 354 nm. Our evaluation shows that GLER is an improvement upon climatological LER databases as it compares well with OMI measurements, and captures the directionality effects of surface reflectance.