bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-Parasitic-Capacitance Self-Aligned 4H-SiC nMOSFETs for Harsh Environment Electronics
Authors: Kurose Tatsuya , Kuroki Shin Ichiro , Ishikawa Seiji , Maeda Tomonori , Sezaki Hiroshi , Makino Takahiro , Ohshima Takeshi , Östling Mikael , Zetterling Carl Mikael
Published: June 2018

Low-parasitic-capacitance 4H-SiC nMOSFETs using a novel self-aligned process were suggested and demonstrated. In these nMOSFETs, device characteristics including parasitic capacitances (gate-source, gate-drain, drain-source capacitance) were investigated and low parasitic capacitance was achieved by the self-aligned structure.
Melt Stirring of Nodular Cast Iron
Authors: Khan Fareed Ashraf , Fredriksson Hasse
Published: June 2018

In this work the effects of stirring/vigorous shearing on matrix and graphite phase in nodular cast iron melt during solidification were studied. Several experiments were conducted for different cooling and stirring times. Samples were prepared and examinations of the microstructure were conducted and compared using Leica Optical Microscope and Scanning Electron Microscope (SEM). In addition, a chemical analysis of the graphite precipitate was performed using EDX equipment mounted on SEM. Oxidation of the melt and formation of oxide nuclei during stirring were observed and analysed. The influence of melt shearing on the structure, nodule count, distribution, area fraction and on overall graphite precipitation was observed and examined with the help of respective computer programs and soft wares. Stirring resulted in increasing the nucleation sites for graphite precipitation thereby increasing the nodule count and area fraction of carbide and transforming the structure from pearlitic matrix to ferritic matrix.
The Experimental Study of Nodular Cast Iron Volume Changes during Solidification
Authors: Tadesse Abel , Fredriksson Hasse
Published: June 2018

The volume changes during solidification of Nodular Cast Iron (NCI) in the sand mold studied using Linear Variable Differential Transformer (LVDT). Both hypo- and hyper-eutectic compositions are considered by adjusting the carbon fraction in the composition during the experimental studies. The microstructural analysis and measurements are taken from the samples to evaluate the different phases present, the nodule count and size distributions. At the beginning of solidification, the experimental result shows the volume change is negligible. During the eutectic growth, the samples expand until the end of solidification. The displacement measurement shows the expansion continued when solidification finished. The volume change studies during solidification indicate that as the carbon fraction increases the volume expansion decreases. On the other hand, it is found that the pore fraction decreases as the volume expansion decreases. The fraction of primary austenite decreases as the fraction of carbon increases, and that leads to having a lower pore fraction.
A New High Strength High Ductile Nodular Iron
Authors: Menk Werner
Published: June 2018

Years ago, especially in Sweden, a new family of ductile iron materials was propagated: Solid solution strengthened ferritic ductile iron. Since the 2011 edition, three grades are integrated into the European Standard EN 1563: EN-GJS-450-18, EN-GJS-500-14 and EN-GJS-600-10. The introduction of these materials into the European standard generated a large interest of many engineers, which came to a real hype meanwhile. The reason is clear: While GJS-450-18 is not very different from the standard GJS-400-15, especially the grade EN-GJS-500-14 promises to have big advantages compared to the standard grade EN-GJS-500-7. Same tensile strength, from 320 MPA to 400 MPa raised 0.2%- proof strength and from 7% to 14 % doubled elongation after fracture are very interesting properties of course and the pure ferritic structure promises a better machinability furthermore. With the higher strength grade EN-GJS-600-10 very early sceptic comments raised, because the Silicon content to reach the required strength is such high, that the risk of an embrittlement of the ferrite even at room temperature and on a tensile test bar is high. But up to now, the grade EN-GJS-500-14 has the reputation to be a high strength and very high ductile material. So, a customer of us also substituted a part from steel to EN-GJS-500-14. All calculations showed a very good performance of the parts, but as soon as in serial production field damages occurred in a manner that the parts completely broke without advance warning. The investigation of the damages showed, that the parts are not only statically and cyclically loaded, but also by strikes. Deeper investigations about strike loads confirmed, that EN-GJS-500-14 is not really ductile under these conditions. The reflection to the philosophy we had with our SiboDur-700 concept, namely to combine a moderate solid solution strengthening with a moderate strengthening by pearlite with Copper, brought us to a new high strength high ductile material we call SiboDur-500. Same strength as EN-GJS-500-14, 10 % lower in 0.2%- proof stress, slightly lower in elongation after fracture, but double to more than four times energy consumption at strike loads depending om temperature!
Evolution of Shrinkage with Carbon Equivalent and Inoculation in Ductile Cast Irons
Authors: Regordosa Anna , Llorca-Isern Nuria , Sertucha Jon , Lacaze Jacques
Published: June 2018

Studying how shrinkage porosity changes size when varying the composition of ductile irons is still of interest for manufacturing sound cast parts and defining optimised processing conditions. Usual changes in carbon and silicon contents strongly affect shrinkage, so that a detailed analysis of the effect of alloy composition and of inoculation level on porosity was carried out in the present study. Two test castings have been used to evaluate the extent of porosity formed using different compositions and inoculation levels. It has been observed that increasing carbon content from hypoeutectic to near-eutectic compositions reduces the amount of defects while a further increase of shrinkage porosity is detected for hypereutectic compositions. Thus, a minimum in shrinkage tendency exists for slightly hypereutectic compositions. Although inoculation decreases shrinkage, the relevance of this parameter varies as a function of carbon equivalent.
Variation of Tensile Properties of High Silicon Ductile Iron
Authors: Hammersberg Peter , Hamberg Kenneth , Borgström Henrik , Lindkvist Joachim , Björkegren Lars-Erik
Published: June 2018

The casting processes are characterized by complex relationships between predictors and responses. It is the fundamental understanding of these complex relationships that often involves hundreds of factors, which improves quality without losing productivity and raising cost. In this work, cast solid solution strengthened ferritic spheroidal graphite irons GJS-500-14 and GJS-600-10 (EN 1563:2012) have been evaluated. These materials offer stronger components with good machinability owing to their even hardness properties. In this case the predictors are chemical composition, gating layout, foundry set-up, testing procedure and equipment etc. and the responses are the tensile properties (Rp0.2, Rm, A5). Here 200 tensile specimens compiled from industrial foundry melts from over 30 years of research have created a state-of-the-art platform for statistical engineering in order to perform Exploratory Data Analysis (EDA) and data visualization. This statistical platform has provided new insight on how foundries should treat complex relationships between predictors and responses in order to identify sources of variation and interaction effects.
Reassessment of Crystal Growth Theory of Graphite in Cast Iron
Authors: Ştefănescu Doru Michael , Alonso Gorka , Larrañaga Pello , de La Fuente Esther , Suárez Ramón
Published: June 2018

The problem of graphite crystallization and growth in cast iron has recently received increased attention. As most of the published literature describe analysis of room temperature graphite, there is a legitimate concern that the crystallization of graphite is concealed by recrystallization and growth in solid state occurring after solidification. To avoid confusion in the interpretation of room temperature graphite morphology, the authors used Field Emission Gun SEM on deep-etched interrupted solidification (quenched) specimens to reveal the morphology of graphite at the very beginning of solidification, when the graphite is in contact with the liquid. Information from related phenomena, such as crystallization of hexagonal structure snowflakes and metamorphic graphite, as well as of diamond cubic structure silicon crystals in aluminum alloys is incorporated in the analysis. Research discussing graphite produced through gas-solid and solid-solid transformations is also examined. Because the faceted growth of graphite is the result of diffusion-limited crystal growth in the presence of anisotropic surface energy and anisotropic attachment kinetics, a variety of solidification morphologies are found. The basic building blocks of the graphite aggregates are hexagonal faceted graphite platelets generated through the growth of graphene layers. As solidification advances, the platelets thicken through layer growth, and then aggregate through mechanisms that may include foliated/tiled-roof crystals and dendrites, curved-circumferential, cone-helix, helical, and columnar or conical sectors growth.
Thermo-Mechanical Fatigue of Grey Cast Iron for Cylinder Heads - Effect of Niobium, Molybdenum and Solidification Time
Authors: Skoglund Peter , Elfsberg Jessica , Ipek Nulifer , Diaconu Lucian Vasile , Larsson Mari , Schmidt Pål
Published: June 2018

Grey iron alloyed with molybdenum and niobium in seven different compositions has been casted using three, in industrial components viable, solidification times which resulted in 21 different samples. The samples have been investigated with respect to microstructure, static properties and thermo-mechanical fatigue performance. It was found that the solidification time is very important for both the static and thermo-mechanical performance. If the solidification time is long the properties are controlled entirely by the large graphite flakes and there is no influence of the alloying elements. On the other hand if the solidification time can be kept short the need for alloying elements may be removed. For the shorter solidification times an influence from the matrix and thus the alloying elements can be seen. It was found that molybdenum enhances TMF-life while no such effect was found for niobium. Niobium, on the other hand, has a larger effect on static strength than molybdenum and also on the cyclic stress in the thermo-mechanical fatigue experiments.
Three-Dimensional Microstructural Characterization of Cast Iron Alloys for Numerical Analyses
Authors: Salomonsson Kent , Jarfors Anders E.W.
Published: June 2018

In this paper, we aim at characterizing three different cast iron alloys and their microstructural features, namely lamellar, compacted and nodular graphite iron. The characterization of microscopic features is essential for the development of methods to optimize the behavior of cast iron alloys; e.g. maximize thermal dissipation and/or maximize ductility while maintaining strength. The variation of these properties is commonly analyzed by metallography on two-dimensional representations of the alloy. However, more precise estimates of the morphologies and material characteristics is obtained by three-dimensional reconstruction of microstructures. The use of X-ray microtomography provides an excellent tool to generate high resolution three-dimensional microstructure images. The characteristics of the graphite constituent in the microstructure, including the size, shape and connectivity, were analyzed for the different cast iron alloys. It was observed that the lamellar and compacted graphite iron alloys have relatively large connected graphite morphologies, as opposed to ductile iron where the graphite is present as nodules. The results of the characterization for the different alloys were ultimately used to generate finite element models.
Solidification Chronology of the Metal Matrix and a Study of Conditions for Micropore Formation in Cast Irons Using EPMA and FTA
Authors: Domeij Björn , Diószegi Attila
Published: June 2018

Microsegregation is intimately coupled with solidification, the development of microstructure, and involved in the formation of various casting defects. This paper demonstrates how the local composition of the metal matrix of graphitic cast irons, measured using quantitative electron microprobe analysis, can be used to determine its solidification chronology. The method is applied in combination with Fourier thermal analysis to investigate the formation of micropores in cast irons with varying proportions of compacted and spheroidal graphite produced by remelting. The results indicate that micropores formed at mass fractions of solid between 0.77 and 0.91, which corresponded to a stage of solidification when the temperature decline of the castings was large and increasing. In 4 out of the 5 castings, pores appear to have formed soon after the rate of solidification and heat dissipation had reached their maximum and were decreasing. While the freezing point depression due to build-up of microsegregation and the transition from compacted to spheroidal type growth of the eutectic both influencing solidification kinetics and the temperature evolution of the casting, the results did not indicate a clear relation to the observed late deceleration of solidification.
Cast Iron Components with Intelligence
Authors: Elmquist Lennart , Carlsson Raul , Johansson Christer
Published: June 2018

The paper describes a project with the aim to develop communicating and functional cast iron components in smart systems. The concept is based on sensors integrated into cast iron components; this will influence not only the component but also the casting process. Among the technical challenges is how to choose a sensor solution that cost-efficiently and with minimal environmental impact can be integrated into the component during the casting process, and especially without being damaged during mold filling and the high pouring temperature. Another challenge is how the iron will interact and interfere with sensor signals and whether an insulating intermediate material is needed or not. Integrating the sensors into the casting makes sensors a natural part of the component, which in turn can lead to more resource efficient designs, increased value added for the casting sector, and a general access to different possibilities of digitalization. The integrated sensors can be used for effective control and monitoring of components when in service and give information about for example how the component is used and what conditions it is exposed to. In other words, the component can tell when maintenance is needed or in worst cases, indicate that something is wrong before a failure will happen. Important measurands can e.g. be elongation, shear, temperature and vibration. Different combinations of sensor materials and insulating materials and their interaction with the cast iron have been investigated. It is shown how the interaction at the interface affects the microstructure and consequently the properties of the cast iron. In the case of insulating materials it is e.g. shown how air gaps are formed and in the case of sensor materials it is shown how a diffusion zone is formed and how this zone depends on the sensor material. How this diffusion zone affects the microstructure is discussed.
Quantified X-Ray Mapping in the WDS Mode
Authors: Runnsjö Gunilla , Grönlund Kaj
Published: June 2018

In material science, there is an increased demand for mapping of microstructural components and their composition. EPMA (Electron Probe Micro Analysis) with WDS (Wavelength Dispersive Spectrometry) is known as having high spectral resolution and sensitivity, but in practice considered to be slow in mapping applications. The present work describes a development of EPMA including design of both instrumental hardware and software related to electronics and calibration.
The Structure of Cast Irons
Authors: Campbell John
Published: June 2018

There appear to be two main growth mechanisms for graphite in cast iron i) Coupled eutectic growth forms of gray irons which are classical growth modes of simultaneous parallel growth of graphite and austenite, not reliant on a bifilm mechanism. These are necessarily fine structures as a result of their control by the rate of diffusion of carbon in the liquid. These structures are well understood. (ii) Uncoupled eutectic mechanisms which appear to be much less well understood, including (a) growth of graphite on silica bifilm substrates floating freely in the melt, forming such structures as A-type graphite flakes. This prediction appears to have now been confirmed by direct observation. The transition to (b) nodular morphology occurs by Mg eliminating the silica bifilms by an exchange reaction. In this way the substrates for flake growth are instantly removed, and graphite can now wrap completely around nuclei, thereby growing as a nodule. Graphite structures in heavy sections such as chunky graphite may now be understandable in terms of the reorganisation by flotation of bifilms and/or nuclei.
On the Primary Solidification of Compacted Graphite Iron: Microstructure Evolution during Isothermal Coarsening
Authors: Hernando Juan Carlos , Diószegi Attila
Published: June 2018

It is widely accepted that in most commercial hypoeutectic alloys, both static mechanical properties and feeding characteristics during solidification, are extremely linked to the coarseness of the primary phase. It is therefore of critical importance to provide tools to control and predict the coarsening process of the dendritic phase present in hypoeutectic melts. The characterization of the primary phase, a product of the primary solidification, has traditionally been neglected when compared to the eutectic solidification characterization in cast iron investigations. This work presents the morphological evolution of the primary austenite present in a hypoeutectic compacted graphite cast iron (CGI) under isothermal conditions. To that purpose, a base spheroidal graphite cast iron (SGI) material with high Mg content is re-melted in a controlled atmosphere and reversed into a CGI melt by controlling the Mg fading. An experimental isothermal profile is applied to the solidification process of the experimental alloy to promote an isothermal coarsening process of the primary austenite dendrite network during solid and liquid coexistence. Through interrupted solidification experiments, the primary austenite is preserved and observed at room temperature. By application of stereological relations, the primary phase and its isothermal coarsening process are characterized as a function of the coarsening time applied. The microstructural evolution observed in the primary austenite in CGI and the measured morphological parameters show a similar trend to that observed for lamellar graphite cast iron (LGI) in previous investigations. The modulus of the primary austenite, Mγ, and the nearest distance between the centre of gravity of neighbouring austenite particles, Dγ, followed a linear relation with the cube root of coarsening time.
Aloe Vera Liquid Crystal Emulsion and Characterization of its Physical Properties
Authors: Tan Wen Ni , Laili Che Rose , Hamdan Suhaimi
Published: June 2018

In this work, liquid crystal emulsion with aloe vera (AV) was formulated and characterised its physical properties. A direct titration method was used to determine the composition of liquid crystal emulsion in a system consisting of water/mixed Tween 80: Span 85/hexane. AV gel was added to produce AV liquid crystal emulsion (AVLCE), which was then subjected to various characterisation such as microscopic analysis, stability test, rheological test and particle size analysis. Results showed that the application of AVCLE employed better performances in terms of stability, particle size and moisturizing. This study suggest that the formulated AVLCE may be suitable to be used as topical application on wounded skin.
The Effect of Temperature on Anatase TiO2 Photoanode for Dye Sensitized Solar Cell
Authors: Jamalullail Nurnaeimah , Mohamad Ili Salwani , Norizan Mohd Natashah , Mahmed Norsuria
Published: June 2018

Dye sensitized solar cell (DSSC) is a well-known photovoltaic device that is used for low power application. One of the main components for DSSC is semiconductor material photoanode which will provide the pathway for electron transportation and thus determine the energy conversion efficiency of the DSSC. The most commonly used material for the semiconductor photoanode is titanium dioxide (TiO2).TiO2is a semiconductor material with wide bandgap material that is existed in three crystalline phase; rutile, anatase and brookite. This paper emphasizes the best annealing temperature for commercialized TiO2, 98% anatase powder where the temperature varies from 300 oC – 600 oC. Through this research, the best annealing temperature for anatase TiO2photoanode is at 420 °C (0.094%) with the crystallite size of 18.76 nm and particle size of 19 nm that is favorable for the dye attached and thus enhances the energy conversion efficiency of the DSSC.
Wettability of Sn-Ti Alloys on Poly-Crystalline CVD Diamond Plates
Authors: Liao Xin Jiang , He Qi Qi , Mu De Kui , Huang Hui , Xu Xi Peng
Published: June 2018

In this paper,in-situwetting and spreading behaviours of the binary Sn-Ti alloys with Ti contents were investigated on poly-crystalline CVD diamond plates. The variation of contact angles at increasing temperatures indicated the wettability of Sn-Ti alloys were strongly influenced by the Ti contents. Addition of small amount of Ti (0.5 wt.%) dramatically reduced the contact angle of Sn-Ti alloys; while a relatively high Ti concentration (above 4 wt.%) induced the formation of large refractory intermetallics phase, which reduced the fluidity and impeded the spreading of Sn-Ti alloys.
Influence of Bi Addition on Wettability and Mechanical Properties of Sn-0.7Cu Solder Alloy
Authors: Ramli Mohd Izrul Izwan , Yusof M.S.S. , Mohd Salleh Mohd Arif Anuar , Said Rita Mohd , Nogita Kazuhiro
Published: June 2018

The effect of bismuth (Bi) micro-alloying additions on wettability and mechanical properties of Sn-0.7Cu lead-free solder were explored. This paper also investigates the influences of various Bi percentages on the suppression of intermetallic compound formation. Scanning electron microscope (SEM) was used to observe the microstructure evolution of solder joint including the thickness of interfacial intermetallic layers. Overall, with the addition of Bi to Sn-0.7Cu solder, the size of primary Cu6Sn5become smaller and suppresses the thickness of interfacial intermetallic compound between solder and the Cu substrate. Microhardness value and wetting properties also increased with Bi addition which resulted in smaller size of β-Sn and Cu6Sn5.
Effect of Al Additions on Corrosion Performance of Sn-9Zn Solder in Acidic Solution
Authors: Jumali Nordarina , Zainol Mohd Hafiz , Mohamad Ahmad Azmin , Mohd Nazeri Muhammad Firdaus
Published: June 2018

The utilization of Sn-Zn based solder on electronic product was only feasible if the corrosion performance of this solder was assured. To achieve this, micro-alloying eutectic Sn-9Zn with Al was proposed. The corrosion performance was evaluated by using potentiodynamic polarization in 1 M HCl at constant scan rate. The microstructure changes due to corrosion exposure was also investigated to further understand the corrosion behaviour changes due to additions of Al. Overall corrosion rate was reduced with the micro-alloying process. Refinement of Zn-rich phase was found to help in producing much lower corrosion current and better passivation film formation on the surface due to the additions of Al. This modification deemed promising and further work should be explored in the future.
Corrosion Performance of Sn-9Zn and Sn-0.7Cuin 3.5% NaCl Solution
Authors: Mohd Rasid Zarrul Azwan , Zainol Mohd Hafiz , Omar Mohd Firdaus , Derman Mohd Nazree , Mohd Nazeri Muhammad Firdaus
Published: June 2018

Corrosion properties of Sn-9Zn and Sn-0.7Cu solder were investigated in 3.5 wt.% NaCl. The scanning rates used were fixed at 1.0mVs-1to study the effect of diffferent adding element which is Cu and Zn into the corrrosion properties of Sn-based solder. The morphological and structural properties of the samples were compared before and after the corrosion. The morphological analysis observed two types of corrosion product which is compacted and loosely-compacted corrosion product after the samples was polarized in 3.5% NaCl solution.
Synchrotron Radiography of Sn-0.7Cu-0.05Ni Solder Solidification
Authors: Xian J.W. , Mohd Salleh Mohd Arif Anuar , Zeng G. , Belyakov S.A. , Yasuda Hideyuki , Nogita Kazuhiro , Gourlay C.M.
Published: June 2018

Sn-0.7Cu-0.05Ni is a widely used Pb-free solder that solidifies into a near-eutectic microstructure and a small fraction of primary Cu6Sn5. This paper overviews in-situ time-resolved imaging experiments on the solidification of Sn-0.7Cu-0.05Ni solder under three conditions: (i) directional solidification, (ii) continuous cooling in a near-uniform thermal field, and (iii) solder joint solidification on a Cu substrate. Primary Cu6Sn5 grow as rods along [0001] in each case but can also grow as X-shaped crystals in (iii). There are significant differences in eutectic growth due to nucleation difficulties for tin in conditions (ii) and (iii).
Tensile Properties of Sn-Bi Lead-Free Solder Alloys
Authors: Yamauchi Akira , Ida Kenta , Fukuda Masahito , Yamaguchi Takuma
Published: June 2018

The Influence of alloy composition on tensile properties of Sn-Bi, Sn-Bi-Cu and Sn-Bi-Ni lead-free solder alloys were investigated. It is found that the elongation of Sn-Bi alloys depend on Bi content, and Sn-40wt% Bi alloy has the highest elongation. The addition of Cu and Ni improves the ductility of Sn 35-45wt% Bi alloys. The fine microstructure of Sn-Bi-Cu or Ni alloys have an effect on the ductility of Sn-Bi based alloys. The elongation increases with decreasing strain rate and increasing temperature. Cu and Ni added to Sn-Bi alloy showed the super plasticity behavior at low strain rate and high temperature (more than 333 K). Moreover, strain rate sensitivity ‘m’ increases with temperature.
Ti(C,N)-Based Cermets: Critical Review of Achievements and Recent Developments
Authors: Lengauer Walter , Scagnetto Fabio
Published: June 2018

The paper describes briefly the historical development and presents in more detail solid-state properties such as hardness, heat conductivity, thermal expansion and mechanical properties of titanium carbonitride Ti (C,N), the basis of the hard phase of cermets. The metallurgy of Ti (C,N)-based cermets with respect to microstructure formation during sintering and the impact on properties are presented in more detail. The various influences such as W and/or Mo content, Mo/W ratio, C content and C/N ratio, binder phase content and binder phase composition (Co/Ni), sintering time, dwell time, alloy state of powders and grain size were critically evaluated and are presented in form of fracture toughness vs. hardness graphs. A table gives a reference list on the study of these influences. TRS data on cermets were collected and summarised in a separate table, too. The focus is put on grades which have the potential of being fabricated soon in industrial processes for production of cermet tools. Application examples for metal cutting, sawing and chip bonding are presented. In two final sections recent modifications and achievements such as graded microstructures, multicomponent binder, and hybrid microstructures are also briefly presented together with an outlook on the future potential of cermet applications.
Effect of WС Content on the Mechanical Properties and High Temperature Oxidation Behavior of Ti(С,N)-Based Cermets
Authors: Zhang Guo Tao , Zheng Yong , Zhao Yi Jie , Zhou Wei , Zhang Jia Jie , Ke Zheng , Feng Ping
Published: June 2018

Ti (C,N)-based cermets with varying WC additions (Ti (C0.6N0.4)-36Ni-12Mo-1C-xWC, x = 0, 3, 6 and 9 wt%) were prepared by conventional powder metallurgy techniques. The microstructure and mechanical properties of all four Ti (C,N)-based cermets were investigated. Isothermal oxidation of all four cermets were also investigated in air at 800°C up to 100 h using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction analysis (XRD). The grains of Ti (C,N)-based cermets became more homogeneous with the increase of WC content. The TRS and fracture toughness increased with the increase of WC content and then decreased when WC content exceeded 6wt%, but hardness decreased continuously with the increase of WC content. The oxide scales formed on the surface of all four samples during the oxidation process were porous and multi-layered, consisting of NiO outerlayer and TiO2 based innerlayer, respectively. The thickness of the oxide scales and oxidation rates increased with the increase of WC content, especially when the content of WC addition reached 9wt%. The cermet with 6wt% WC addition showed excellent mechanical properties and acceptable high temperature oxidation resistance.
Structure, Mechanical Properties and Corrosion Resistance of MgCa5 and MgCa5Zn1 Alloys after Plastic Deformation
Authors: Nowosielski Ryszard , Gawlas-Mucha Agnieszka , Babilas Rafał
Published: June 2018

Binary Mg-Ca and ternary Mg-Ca-Zn alloys are a new group of magnesium materials, which can be used in many goods. Among others, biomedical applications of these alloys mainly involved surgical implants in the form of plates or screws. In order to improve mechanical properties and corrosion resistance of Mg-based alloys with Ca and Zn addition in as-cast state a plastic deformation was applied by using the KOBO extrusion method. The microstructure studies conducted by scanning microscopy show that the structure of the alloys after the plastic deformation exhibits banding character and the bands are oriented in the direction of an extrusion. A significant increase of mechanical properties was observed for MgCa5Zn1 alloy. After the plastic deformation, the corrosion potential determined for the MgCa5 and MgCa5Zn1 alloy is shifted into the positive direction, which may suggest the increase of corrosion resistance. Moreover, the MgCa5 alloy in as-cast state was completely dissolved after 288 h of immersion in Ringer’s solution. A volume of hydrogen evolution for the same alloy after plastic deformation showed a value of 35 ml/cm2.
Heat Treatment of Al-Si-Cu Alloys
Authors: Krupiński Mariusz , Król Mariusz , Maniara Rafał
Published: June 2018

The aim of the presented work is an effort to answer the research questions, i.e. how to determine the optimal supersaturation temperature for multicomponent alloys? What is the relationship between changes in the derivative curve of composites and the relationship between their chemical composition and microstructure? Searching for the right answer to the above questions was the basis for determining the scope and methodology of the presented work. To describe the phenomena that occur in the material during solidification under various conditions caused by the variable cooling rate and variable chemical composition it was decided to use thermal-derivative analysis methods. The mentioned method allows to accurately describe and interpret the kinetics of the crystallization of the tested materials. This method is often used in the search for new directions of modern technologies, attractive from both experimental and cognitive. This methodology allows to determine the relationship between crystallization kinetics and usable casting properties on the example of Al-Si-Cu alloys and other alloying elements.
Field selectivity of a spinosad-poisoned bait toward target tephritids and non-target insects
Authors: Infusino Marco , Iannotta Nino , Scalercio Stefano
Published: June 2018

One of the key-points in sustainable agriculture is to minimize the amount of pesticides inputs in agro-ecosystems increasing selectivity of active agents on target pests mainly. According to this perspective, control strategies utilising baits receive a growing interest. a spinosad-poisoned sugar-based bait, the so called GF-120 bait, utilised against diptera Tephritidae, recently appeared on the market. The toxicity of spinosad for non-target insects is demonstrated by several authors. However, the amount of pesticide applied is strongly reduced by using it with an attractive food-bait, even if field evidences on the selective attraction of this bait are missing. The aim of this paper is to evaluate the selectivity of GF-120 bait toward target and non-target insects under field conditions, focussing our attention on pollinators. Field trials were performed in a 20 years old olive orchard, where 12 baited and 12 unbaited traps were positioned for insect monitoring. The abundance of the most common orders of insects and target pest species Bactrocera oleae and Ceratitis capitata has been assessed. The main finding of this research is that many pollinators are not attracted by the bait, while target and non-target diptera are significantly attracted by the bait with the exception of Muscidae. The attraction toward a part of non-target diptera should be better explored in order to avoid negative impact on beneficial and non-target species. The need of pest control strategies safer for the environment and the wild populations of non-target organisms seems to be satisfied by the use of this bait.
Nuovi dati sui Coleotteri Tenebrionidi della città di Roma (Coleoptera Tenebrionidae)
Authors: Fattorini Simone , Porena Boris , Bernardini Francesca , Di Giulio Andrea
Published: June 2018

Per la città di Roma erano state finora segnalate con certezza 45 specie di tenebrionidi. Lo studio di materiale raccolto tra il 1940 e il 1950, ma precedentemente non esaminato, ha permesso di evidenziare la presenza in passato di tre ulteriori specie. tali dati suggeriscono che l’estinzione di tenebrionidi a Roma abbia coinvolto più specie di quante fosse stato possibile accertare in precedenza a causa della scomparsa “precoce” di specie già rare e di difficile raccolta, e pertanto non presenti nel materiale già noto. Indagini recenti, inoltre, hanno consentito di confermare una specie la cui presenza era stata considerata dubbia. Infine, sono riportati dati su ulteriori 25 specie già note con certezza della città.
Prima segnalazione per l’Italia di Tarsostenus carus (Coleoptera Cleridae)
Authors: Zappi Iuri
Published: June 2018

Viene segnalata per la prima volta la presenza in Italia di Tarsostenus carus (Newman, 1840) sulla base di un esemplare femmina raccolto nelle Marche nel 1999. La specie è originaria della regione australiana e risulta essersi già acclimatata in Europa, in particolare in Gran Bretagna e Francia. Vengono fornite brevi notizie sulla sua tassonomia, biogeografia ed ecologia.
Insects collected from wood infested with Pityophthorus juglandis Blackman (Coleoptera Curculionidae Scolytinae) in the Piemonte region, Northwestern Italy
Authors: Bosio Giovanni , Cooke-McEwen Crystal
Published: June 2018

The walnut twig beetle, Pityophthorus juglandis Blackman (Coleoptera Curculionidae Scolytinae), and thousand cankers disease are documented in the Piemonte region of Northern Italy for the first time.  Northern California is found to be the likely origin of the Piemonte walnut twig beetles based on the comparison of CO1 haplotypes. Multiple species of parasitoids have been reared from black walnut wood infested with the invasive walnut twig beetle.  These rearings constitute the first record of the genus Neocalosoter Girault and Dodd (Hymenoptera Pteromalidae Cerocephalinae) in Europe and are likely due to accidental introduction along with the host beetle. Two specimens of Theocolax spp. are described as morphological anomalies with geographical origins unknown.
The Orthoptera fauna of the Stelvio National Park
Authors: Baroni Daniele , Bonifacino Marco , Cristiano Luca , Rossi Roberta , Pedrotti Luca , Sindaco Roberto
Published: June 2018

Within the Project “Animal Biodiversity Monitoring in the Alpine Environment” the Orthoptera fauna has been studied in a three-year period (2013-2015). The first check-list of the protected area, with ecological and biogeographical notes, is presented. We found 40 species (16 Ensifera, 24 Caelifera), corresponding to 11% of the Italian Orthoptera fauna. A geographic differentiation in species distribution among the three areas (Alto Adige - BZ, Trentino - TN and Lombardy - BS and SO) has been detected. The genus Barbitistes is represented by B. serricauda in Alto Adige and B. alpinus in Trentino and Lombardy. Kisella irena is restricted to Peio and Rabbi Valleys only, in connection with this species distribution in Trentino. Within the Park, Euthystira brachyptera is distributed only in Lombardy, despite its habitat is apparently extensively available also in Trentino and Alto Adige. We found Omocestus haemorrhoidalis and Chorthippus vagans only in Val Venosta (BZ). Only two species, previously reported for the study area, has not been detected during our surveys: Celes variabilis and Ruspolia nitidula. The first site of presence of Tettigonia caudata, rare in Italy, within the Park boundaries has been discovered near Martello (BZ). Two endangered taxa of high conservation value, Epacromius tergestinus ponticus and Crysochraon dispar, reported in the last Century just outside the Park boundaries, are probably extinct today due to habitat loss.
Atti Sociali
Authors: Italiana Società Entomologica
Published: June 2018

non disponibile
Anesthetic Management of a Neonate with Congenital Diaphragmatic Hernia under High-Frequency Oscillatory Ventilation
Authors: Edipoglu Ipek S. , Celik Fatma , Ozdogan Tutku , Comert Serdar , Guvenc B. Haluk
Published: June 2018

Perioperative management of a neonate with congenital diaphragmatic hernia (CDH) is challenging because of pulmonary hypoplasia, pulmonary hypertension, and respiratory insufficiency. In this report, we present our intra-operative experience in a 4-days old and 3070 grams CDH neonate. He was admitted to neonatal intensive care unit and intubated due to severe respiratory insufficiency. He showed signs of severe pulmonary hypoplasia and his echocardiography revealed a cardiac dextroversion. The patient was relatively stabilized after four days under combined high-frequency oscillatory ventilation (HFOV) and inhaled nitric oxide (iNO). A corrective surgical intervention was sustained with dopamine, dobutamine, fentanyl and midazolam infusions. Ventilator settings were: 9 cmH2O MAP; 15-Hz frequency; 30 cmH2O amplitude and 55% FiO2. Venous-blood gas analysis indicated pH:7.38 pO2:36.2, pCO2:39.2 with SpO2:98%. We believe that HFOV and iNO combination is an effective alternative for the anesthetic management of CDH cases as it provides better gas exchange and less volutrauma.
Exploration of Factors Perceived to Influence Development of Diagnostic Reasoning in Athletic Trainers and Athletic Training Students
Authors: Kicklighter Taz H. , Geisler Paul R. , Barnum Mary , Heinerichs Scott , Martin Malissa
Published: June 2018

Context:

Diagnostic reasoning is acknowledged as a vital skill for medical practice, but research regarding this core aspect of medical cognition as it pertains to athletic training contexts is scarce. To compare athletic training–specific clinical reasoning skills with those of other health care practitioners, educators need to better understand how athletic trainers (ATs) think, what helps them think better, and what may hinder their thinking skills as related to diagnostic reasoning challenges in the clinical context.

Objective:

To conduct a preliminary investigation into ATs' and undergraduate athletic training students' perceptions about their diagnostic reasoning processes. Secondarily, to identify and compare activities or practices that may influence individual diagnostic reasoning abilities.

Design:

Qualitative research.

Setting:

Online interviews.

Patients or Other Participants:

Twenty-three participants (11 ATs, 12 senior-level athletic training students) were convenience sampled from a pool of participants used in a separate, multifaceted diagnostic reasoning study.

Main Outcome Measure(s):

Participants were interviewed in an online format to determine their diagnostic processing ability and perceived factors that enhance and hinder diagnostic reasoning. Data were analyzed using a general inductive approach.

Results:

Analysis determined ATs and athletic training students used similar reasoning processes to previously reported expert- and novice-level reasoning abilities, respectively. Professional socialization and metacognitive activities were found to enhance individual diagnostic reasoning abilities in both groups. Lack of professional socialization and time in ATs and limited experiences and educational settings in athletic training students were thought to detract from diagnostic reasoning development.

Conclusions:

Use of diagnostic reasoning and factors perceived to influence ATs' and athletic training students' ability found within our study correspond with previously reported theories and mimic the current understanding of expert and novice abilities respectively. Understanding factors that influence diagnostic reasoning ability is crucial for developing effective pedagogical and curricular strategies in athletic training education.
Athletic Therapy Students' Perceptions of High-Fidelity Manikin Simulation: A Pilot Study
Authors: Miller Matthew B. , Macpherson Alison K. , Hynes Loriann M.
Published: June 2018

Context:

Athletic therapy students learn emergency skills through a variety of modes, including students portraying injured athletes and cardiopulmonary resuscitation manikins. Although acceptable and satisfactory forms of teaching, these methods are limited in their ability to create realistic physiological symptoms of injury.

Objective:

To assess how athletic therapy students perceive their learning needs (LNs) relative to the use of high-fidelity manikin simulation (HFMS) compared with student simulation (SS) in the laboratory setting.

Design:

Pretest-posttest study design.

Setting:

Nursing Simulation Centre, Sheridan College, Brampton, Ontario, Canada.

Patients or Other Participants:

Thirty students from the Bachelor of Applied Health Science (Athletic Therapy) program at Sheridan College in years 2 and 4.

Intervention(s):

Perceived LNs related to the use of the Laerdal Medical SimMan3G HFMS contrasted with the use of SS for learning to respond to a prescribed emergency scenario.

Main Outcome Measure(s):

Participants completed questionnaires for both the SS and HFMS environments that consisted of 16 specific LNs spanning the cognitive, psychomotor, and affective domains of learning. Paired t tests and a 2-way analysis of variance were used to analyze the questionnaire data.

Results:

Participants reported all LNs as being equally important in both environments, but HFMS was identified as a better environment for achieving 13 of the 16 LNs. The mean change from pretesting to posttesting of all LNs in the affective domain improved significantly (P < .05) in the HFMS environment. Year 4 participants deemed HFMS to be a more effective means of learning in the cognitive and psychomotor domains (P < .05).

Conclusions:

The HFMS experience enhanced athletic therapy students' perceptions of their confidence, base of knowledge, decision-making skills, and overall acute management of critical lifesaving situations. The HMFS environment is a more effective tool for addressing the LNs in the affective domain, which includes skills related to confidence, attitudes, values, and appreciations.
Экстремальные задачи в неквазианалитических классах Карлемана. Приложения
Authors: Gaisin Ahtyar Magazovich
Published: June 2018

Изучается экстремальная задача в семействе функций из неквазианалитического класса Карлемана на отрезке, обращающихся в нуль в некоторой точке отрезка со всеми производными. Указаны приложения в теории приближений, в частности для системы экспонент, показатели которых удовлетворяют условию Фейера (или Левинсона), получена асимптотическая оценка расстояния от фиксированной экспоненты до замыкания линейной оболочки остальных элементов системы в $C_{[0,\delta]}$ при $\delta\to 0$.
Библиография: 25 названий.
О росте многочленов ортогональных на единичной окружности с весом $w$, удовлетворяющим условиям $w,w^{-1}\in L^\infty(\mathbb T)$
Authors: Denisov Sergey Aleksandrovich
Published: June 2018

Рассматриваются многочлены $\{\varphi_n(z,w)\}$, ортогональные на окружности с весом $w$, удовлетворяющим условию $w,w^{-1}\in L^\infty(\mathbb{T})$. Показывается, что норма $\|\varphi_n(e^{i\theta},w)\|_{L^\infty(\mathbb{T})}$ может расти определенным образом с ростом $n$.
Библиография: 21 название.
The impact of Basel III on money creation: a synthetic theoretical analysis
Authors: Xiong Wanting , Wang Yougui
Published: June 2018

Inspired by the extensive criticisms against the textbook fractional reserve theory, this paper revisits the mechanics of money creation process and complements the traditional focus on the reserve requirement by elaborating on the roles of three prudential regulations proposed in the Basel III accord. In particular, the authors consider such conditions where the financial markets are imperfect and suffer from various frictions that the commercial bank cannot readily modulate their liquidity and capital buffers, especially at an aggregate level or within a short period. Meanwhile, as a result of maturity mismatch and fundamental uncertainty, the credit and money creation activities inevitably add to the liquidity and insolvency risks faced by the bank. Under the assumptions that the levels of bank reserves, capital and government bonds are exogenously given, and that the concerned prudential regulations are always binding, the authors examine the determinants of the broad money aggregate and the money multiplier. Specifically, they find that 1) the money multiplier under Basel III is not constant but a decreasing function of the monetary base; 2) the determinants of the bank’s money creation capacity are regulation specific; 3) when multiple regulations are imposed simultaneously, the effective binding regulation and the corresponding money multiplier will vary across different economic states and bank balance sheet conditions.
O direito à cidade e os movimentos sociais: o Movimento #OcupeEstelita e a materialização da utopia
Authors: Dias Luan Guilherme , Silva Juvêncio Borges
Published: June 2018

O presente estudo tem por objetivo analisar o conceito de direito à cidade e o significado de sua apropriação pelos movimentos sociais na contemporaneidade, a fim de compreender a atuação do Movimento #OcupeEstelita, na cidade de Recife-PE. Em meio ao caos das grandes cidades, que adotam o modelo desenvolvimentista como o único possível, as concepções de Henry Lefebvre renascem e ganham vida com a ação coletiva dos movimentos sociais, a partir de atos contestatórios, que buscam a transformação do espaço urbano em local de convivência, descoberta e sociabilidade. A pesquisa realizada, conjugando o método dedutivo com o indutivo, a partir da análise de dados qualitativos, de natureza bibliográfica e documental, permite concluir que a utilização do conceito de direito à cidade pelos movimentos sociais possibilita o florescimento de uma nova realidade urbana, centrada no bem-estar coletivo das pessoas, como demonstra o Movimento #OcupeEstelita, que materializa o direito à cidade na capital de Pernambuco.
Sediment remediation can include no action
Authors: Chapman P.M.
Published: June 2018

This short Commentary briefly reviews contaminated sediment risks, the 4 factors that determine appropriate remedialÂ alternatives, and situations where the no action (other than monitoring) alternative may be appropriate. References and anÂ example involving mercury-contaminated sediments is provided. Remediation alternatives other than no action should notÂ cause more environmental harm than they prevent.