bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of Micro Three Dimensional Structures by Two Photon Polymerization with SiO/Resin
Authors: Herrera Salazar Maria Guadalupe del Rocio , Akiyama Hiroyuki , Nakayama Tadachika , Suematsu Hisayuki , Niihara Koichi
Published: October 2016

In this paper we presented the synthesis of TEOS with photoresist in order to use it like a hybrid material for 3D printer on the micrometer scale by means of the two-photon polymerization process, in which two photon are absorbed simultaneously by the material using an ultrafast laser causing its polymerization. We analyzed the mix of TEOS and photoresist with UV-VIS and FTIR spectrometers, checking that complies with two important conditions: has an optical transmission at 780 nm and absorbs at 390 nm. Finally we fabricated micro-structures with a new hybrid material; TEOS does not absorb the laser in this system and does not interfere with the formation of a three-dimensional structure. After formation the 3D microstructure, samples were heated to form the SiO. These samples of microstructures were observed under digital microscope and SEM.
New Directions of Health Monitoring for Building Structures
Authors: Nishitani Akira , Xiang Ping , Marutani Shohei , Hatada Tomohiko , Katamura Ryuta
Published: October 2016

The concept of structural health monitoring (SHM) has appealed the attentions of structural engineers. However, most of the proposed schemes for SHM do not seem “friendly” to the practicing engineers in terms of the used data or employed methods. In this regard, the direct sensing of inter-story drift displacements could open the door to the construction of “practicing engineers friendly” SHM schemes. The authors‘ group developed non-contact types of inter-story drift displacement sensors. Several schemes based on the drift displacement sensing are discussed, which do not involve heavy researchers-oriented processes.
Positioning Units for Critical Asset Tracking and Emergency Management
Authors: Vittuari Luca , Pavkovic Bogdan , Guinamard Alexis , Casciati Fabio , Zanzi Matteo , Ghetti Antonio , Berbakov Lazar , Vece Michele
Published: October 2016

Motivated by the opportunity to develop industry pull applications and services for the European EGNOS and GALILEO satellite systems, within SPARTACUS project are being tested satellite based positioning units aided by small inertial navigation platforms. In particular, three different types of tracking units were designed and realized for: (i) freight trains tracing, (ii) relief goods distribution, and (iii) coordination of first responders. In order to improve the positioning accuracy in presence of several units installed on the same convoy, were developed software solutions based on two steps (low and high level) in order to allow the integration of information collected by the individual tracking unit and by the whole array of sensors.
A Magnetostrictive Energy Harvesting System for Bridge Structural Health Monitoring
Authors: Clemente Carmine Stefano , Davino Daniele , Maddaloni Giuseppe , Pecce Maria Rosaria , Visone Ciro
Published: October 2016

Energy harvesting is a solution to feed wireless sensors for bridge structural health monitoring. Indeed, vibrations induced by traffic passing can be converted into electrical energy with suitable devices. This paper presents laboratory tests over a device based on galfenol rods, a magnetostrictive material. It is presented the general design and both mechanical and magneto-mechanical tests to verify the performance.
FBG-Galfenol Integrated Magnetic Field Sensors for Harsh Environments
Authors: Apicella Valerio , Caponero Michele Arturo , Cianfarani Cesidio , Davino Daniele , Polimadei Andrea , Visone Ciro
Published: October 2016

The paper aims to discuss the basic issues related to the analysis and design of magnetic sensors based on the employment of magneto-active materials. In particular, the basic idea is based on the integration of a Galfenol magnetostrictive alloy to a Fiber Bragg Grating (FBG) embedded into an optic fiber, able to sense the deformation of the material induced by magnetic field. The structure of the alloy and the characteristics of the fiber, make the device suitable to work also in harsh envi- ronments. One of the basic goals is to provide a sensor as simple as possible, with high field range detection and, at the same time, low reconstruction error. It has been observed that the increase of the field range could be achieved by exploiting the effects of the demagnetizing field, without exploit- ing the well-known magnetic hardening induced by the applied stress. In fact, the latter requires a clamping system, resulting in the increase of the sensor size. The demagnetizing field, conversely, provides a shielding of the external field, turning away the undesired approach to saturation. Finally, the employment of a material characterized by weak hysteresis phenomena avoids the use of complex compensation algorithm without losing accuracy. Some result of its characteristics and performances are provided.
Robotic Fish Development for the Next Generation Underwater Vehicle
Authors: Yamamoto Ikuo
Published: October 2016

The author has developed many kinds of robotic fishes based on elastic oscillating fin propulsion system from 1989. The presentation describes past, present, and future robotic fish technologies, and applications of robotic fish technologies to various fields. Firstly, the history of the developed life-like robotic fish, such as sea bream in 1995, coelacanth in 1997, carp in 2000, shark ray in 2004 etc. is mentioned. The developed robotic fishes are basically propelled by vertical tail fin and operated by servo motors. Secondly, the life-like robotic dolphin was newly developed in 2013. The author developed tethered whale robot with horizontal tail fin propelled by hydraulic actuator in 1990s, however, the robotic dolphin is untethered and higher length, that is more than 1m, and has characteristic of fast cruising and higher maneuverability with horizontal tail fin propelled by servo motors. Thirdly, new application fields of robotic fish technologies, such as medical forceps and extractors, space robots which went to International Space Station and swam in the space, and current power plant using oscillating fin propulsion system for new offshore sustainable energy are described. Finally, robotic fish technologies for the next generation underwater vehicle are summarized.
Antibacterial Nanocoatings for Ocular Applications
Authors: Baino Francesco , Perero Sergio , Miola Marta , Ferraris Monica
Published: October 2016

Bacterial issues in ophthalmic applications, with particular reference to postoperative infection of ocular implants, cause significant problems that often require additional, stressful and expensive treatments for the patients. In this work we applied silver-containing antibacterial costings on two kinds of polymeric ocular devices, i.e. silicone scleral buckles for retinal detachment surgery and poly(methyl methacrylate) artificial eyes for enucleated patients. The coatings (thickness around 50 nm), constituted by silver nanoclusters embedded in a silica matrix, were produced by RF co-sputtering and investigated by SEM and EDS. The antibacterial effect of the coating was confirmed by the in vitro formation of an inhibition halo against Staphylococcus aureus, which is one of the most common pathogens involved in ocular infections. The approach proposed in this study for treating implant-related ocular infections can have a significant impact in the field of ophthalmic biomaterials, suggesting a valuable alternative to the administration of antibiotics that may become ineffective towards resistant bacterial strains.
A Protease-Activated Ratiometric Fluorescent Probe for pH-Mapping of Malignant Tumor
Authors: Hou Yi , Zhou Jin , Gao Zhen Yu , Sun Xiao Yu , Liu Chun Yan , Shangguan Di Hua , Yang Wen Shang , Gao Ming Yuan
Published: October 2016

A protease-activated ratiometric fluorescent probe based on fluorescence resonance energy transfer between a pH-sensitive fluorescent dye and biocompatible Fe3O4 nanocrystals was constructed. A peptide substrate of MMP-9 served as a linker between the particle quencher and the chromophore that was covalently attached to the antitumor antibody. The optical response of the probe to activated MMP-9 and gastric cell line SGC7901 tumor cells was investigated, followed by in vivo tumor imaging. Based on the ratiometric pH response to the tumor microenvironment, the resulting probe was successfully used to image the pH of subcutaneous tumor xenografts.
Fractional Calculus Approach to Relaxation Behavior of Amorphous Shape Memory Polymers
Authors: Fang Chang Qing , Sun Hui Yu , Gu Jian Ping
Published: October 2016

To select an appropriate relaxation kernel function is significant for shape memory polymers (SMPs) in their thermomechanical constitutive models. The relaxation modulus of SMPs are described by fractional-order viscoelastic (FOV) kernel and three other kinds of viscoelastic kernel, that is, Prony series, Kohlrausch-Williams-Watts (KWW) kernel and Cole-Cole Model (CCM) kernel. The data fitting result shows FOV kernel is a valuable tool to describe the relaxation response of SMPs. Compared with Prony series, KWW kernel and CCM kernel, the FOV kernel can give a comparative description of relaxation modulus of SMPs with fewer material parameters.
Effects of Pseudoelastic Cycling under Different Temperatures on Physical and Mechanical Properties of a NiTi Alloy
Authors: Mendes Rodrigues Mariana Carla , Soares Guilherme Corrêa , Lopes Buono Vicente Tadeu , de Arruda Santos Leandro
Published: October 2016

The effects of pseudoelastic cycling under different temperatures on physical and mechanical properties of a NiTi superelastic wire were investigated by uniaxial tensile testing. The samples were cyclically deformed up to 6% strain under several test temperatures above the austenite finish temperature (Af). In order to approach a cyclic saturation level, number of cycles was established as 20. The temperature at which mechanical cycling was performed played a strong role on residual strain, dissipated energy and also on the critical stress to induce martensite, being consistent with the Clausius-Clapeyron relationship. It was found that an increase in test temperature resulted in more significant changes in the alloy’s functional behavior, but cyclic stability tended to be reached within fewer cycles. X-ray diffraction results showed that no martensite was stabilized at any condition and that austenite diffraction peaks intensities increased with test temperature, which was attributed to stress relaxation. Tensile tests until rupture and three point bending tests revealed that the mechanical response of the specimens cycled at higher temperatures and as received were fairly similar, and that specimens cycled at lower temperatures exhibited a slightly higher flexibility.
Effects of an External Magnetic Field on Polymeric Foam-Ferromagnet Composites
Authors: D'Auria Marco , Volpe Valentina , Davino Daniele , Pantani Roberto , Sorrentino Luigi
Published: October 2016

Composite lightweight materials based on a polymeric matrix with embedded magnetic micro-particles have been developed. The application of a magnetic field (MF) during the foaming of samples induced the alignment of magnetic particles along the MF lines, forming reinforcing chain-like structures. The presence of aligned micro-particles imparted an anisotropic mechanical behavior along the particle alignment direction, thus strongly improving mechanical stiffness and strength compared to randomly filled systems. The application of a MF on pre-strained samples during the magneto-mechanical characterization resulted in a direct relationship between the measured variation of the elastic modulus of the foam and the time dependent intensity of the applied MF (also for a magnetic field strength as low as 200 kA/m). In particular, all reinforced samples pre-strained in the linear elastic region of the stress-strain curve exhibited a magneto-strictive response (negative variation of the measured stress). On the contrary, a positive variation of the measured stress (strengthening effect) was detected in samples with aligned particles at pre-strains above the yield point. This behavior has been related to the tendency of chain-like aggregates in buckled cell edges to re-align along the MF lines.
New Resonance Mode of Dielectric Elastomer Minimum Energy Structure
Authors: Zhao Jian Wen , Ge Yong , Wang Shu , Huang Bo
Published: October 2016

The dielectric elastomer minimum energy structure (DEMES) can realize large angular deformations by a small voltage-induced strain of the dielectric elastomer, so it is a suitable candidate to make a rotary joint for a soft robot. Driven with an alternating electric field, the joint deformation vibrational frequency follows the input voltage frequency. However, the authors find that if the rotational angel over a negative angle during dynamic response, the resonance mode will be different from the traditional, the vibration with the largest amplitude does not occur while the voltage frequency is equal to natural response frequency of the joint. Rather, the vibrational amplitude will be quite large over a range of other frequencies, at which the voltage frequency is greater than one time of the nature frequency and smaller than two times. This phenomenon was analyzed by relationship between the bending angle, applied voltage and bending moment of the film to the frame on a timeline. This new resonance mode can be applied to some biomimetic soft robots that consist of DEMES rotary joint.
Group-Velocity Anomaly Modes in Hybrid Bands of Photonic Crystals Made of Ferroelectrics
Authors: Takeda Mitsuo Wada , Arikawa Akihiko , Araki Ryohei , Nakata Yosuke , Miyamaru Fumiaki , Yamaguchi Toshihisa
Published: October 2016

In photonic crystals composed of ferroelectrics, the hybrid bands with corresponding to new additional band gaps are expected to appear around the Brillouin zone’s center and boundaries. In this hybrid bands, the group-velocity anomaly modes related to the phonon-polariton branches are expected to be discovered. Propagation characteristics of the group-velocity anomaly modes in the hybrid bands of one-dimensional photonic crystals fabricated by ferroelectric Li2Ge7O15 single crystals are discussed on the basis of finite element method and finite-difference time-domain numerical analyses and experimental results obtained by terahertz time-domain spectroscopy. It is founded that the electric-field intensity of the standing-wave mode at the end point of the dielectric band branch is found to be localized around all of the ferroelectrics plates in the photonic crystal. In contrast, group-velocity anomaly mode in the vicinity of the standing-wave mode is strongly localized around the first ferroelectrics plate on the incident side and decays as it propagates through the following ferroelectrics plates.
Aerogels Based on Microwave Plasma Torch Synthesized Graphene
Authors: Sultanov Fail R. , Mansurov Z.A. , Pei S.S. , Chang S.C. , Xing S. , Robles-Hernandez F. , Chi Y.W. , Huang K.P.
Published: October 2016

In this research aerogels were synthesized by homogenization of carbon nanotubes and chitosan under ultrasonic treatment and active magnetic stirring, followed by freeze-drying in order to remove the liquid from its structure. Freeze-drying is characterized by a certain ratio of pressure and temperature at which the solid phase, in our case - the ice, turns into a gas without passing through a liquid phase. Freeze-drying was carried out at a temperature of-5 ° C and a pressure of 30-80 Pa. After freeze-drying which lasted for 20 hours, the as-obtained aerogels were carbonized at temperature of 800 °C in an inert atmosphere. Surface morphology of resulting aerogels was studied using scanning electron microscopy. The hydrophobicity and sorption capacity of these aerogels to organic liquids characterized by different densities were investigated. In addition, composite aerogels with the presence of graphene layers in the structure were obtained and the influence of introduction of graphene on aerogel’s properties was analyzed. It was found that composite aerogels based on graphene and carbon nanotubes with chitosan as a glue matrix are characterized by a better-developed porosity of surface with a smaller pore sizes, and their sorption capacity for organic liquids is also higher compared with the aerogels based on carbon nanotubes.
Glass-Derived Photonic Crystal Structures
Authors: Chiappini Andrea , Armellini Cristina , Carpentiero Alessandro , Pasquardini Laura , Lunelli Lorenzo , Vaccari Alessandro , Pelli Stefano , Lukowiak Anna , Pederzolli Cecilia , Righini Giancarlo C. , Ramponi Roberta , Ferrari Maurizio
Published: October 2016

In this paper we report on the fabrication and the characterization of colloidal systems considering complementary structures based on responsive artificial opal both in direct and inverse configuration. We will discuss alternative systems such as: (i) chromatic composite structure as chemical sensor based on polystyrene (PS) nanoparticles (NPs) embedded in elastomeric matrix, where the application of specific organic solvents produces a variation of its color; (ii) metallic dielectric structures, where the infiltration of colloidal crystals with metallic nanoparticles permits to modify the optical properties of the common opal and can be usefully exploited as SERS substrates; (iii) inverse silica opal functionalized with fluorescent aptamers in order to develop bio-sensors in dye labelled fluorescence detection scheme.
Recent Progress of Transparent Ceramic Scintillators
Authors: Yanagida Takayuki
Published: October 2016

Recent progress of transparent ceramic scintillators is reviewed. The present work reports the research and development of oxide transparent ceramic materials such as garnet, sesquioxide, complex perovskite and some other kinds. Some representative scintillation properties such as scintillation emission spectra and decay times under X-ray irradiation are presented. Gamma-ray induced scintillation detector properties including pulse height spectrum, energy resolution, and light yield nonproportionality are also shown.
Synthesis and Characterization of Lanthanide Metal-Organic Frameworks with Perfluorinated Linkers
Authors: Laurikėnas Andrius , Barkauskas Jurgis , Kareiva Aivaras
Published: October 2016

In this study, lanthanide elements (Ln3+) and 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid (TFBDC) based metal-organic frameworks (MOFs) were synthesized by precipitation and diffusion-controlled precipitation methods. Powders insoluble in aqueous media and polar solvents were obtained. The microstructure and properties of Ln3+ MOFs were evaluated and discussed. X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and fluorescence spectroscopy (FLS) were carried out to characterize Ln3+ MOF's crystallinity, the microstructure, chemical composition and optical properties.
The Basic Properties of the Ferroelectromagnetic Composites Based on the Ferrite and PZT-Type Powders
Authors: Bochenek Dariusz , Niemiec Przemysław , Skulski Ryszard , Dercz Jolanta
Published: October 2016

In this paper a ferroelectric–ferromagnetic composites based on a doped PZT-type and ferrite powders were presented. Ferroelectric powder (in amount of 85.0 wt-%) was based on multicomponent PZT-type materials: i) Pb(Zr0.51Ti0.49)O3+0.2%at.Bi2O3+0.03%at.Nb2O5+ 0.06%at.MnO2, ii) Pb0.84Ba0.16(Zr0.54Ti0.46)O3+1.0%at.Nb2O5, while nickel–zinc ferrite Ni0.64Zn0.36Fe2O4 (in amount of 15.0 wt-%) served as the magnetic component of the composite samples. The synthesis of the ferroelectric–ferromagnetic composite’s powders was performed by solid state method, while final densification of the synthesized powders was achieved using free sintering method.Conducted basic tests indicate that obtained ferroelectromagnetic ceramic composites (PZT-ferrite type) exhibit good properties giving the possibility to use them to construct magnetoelectric transducers.
Grafting of TiO2 on PMMA Film and Reusability in Photodegradation of Organic Dye
Authors: Klaysri Rachan , Wichaidit Sopita , Praserthdam Piyasan , Mekasuwandumrong Okorn
Published: October 2016

Grafting TiO2 on PMMA was studied by atom-transfer radical-polymerization (ATRP). Each step in grafting process was monitored by fourier transform infrared spectroscopy (FT-IR), 1H NMR and 13C NMR spectra. The glass temperature of grafted-PMMA film was determined by using differential scanning calorimetry (DSC). The morphology and bulk composition were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The surface composition was characterized by X-ray photoelectron spectroscopy (XPS). As results, a novel method of grafting TiO2 on PMMA was successfully grafted and confirmed in various techniques. The photocatlytic activity was evaluated under UV and visible light irradiation. The reusability of TiO2-g-PMMA films was studied in details.
Photocatalytic Activation of TiO2 Biomaterials by UV and X-Rays
Authors: Cheung Keng Ho , Koshy Pramod , Pabbruwe Moreica Beatrice , Lee Brendan , Sorrell Charles Christopher
Published: October 2016

TiO2 films of varying mineralogical and microstructural characteristics were fabricated on sand-blasted Ti6Al4V plates by anodisation in 2 M sulphuric acid (H2SO4) and 2 M phosphoric acid (H3PO4) at 120 V and 300 mA/cm2 for 10 min and 15 min, respectively. The film formed by anodisation in H2SO4 consisted of both anatase and rutile while the film formed by anodisation in H3PO4 consisted only of rutile. This inconsistency is attributed to the presence of anatase below the level of detection in the sample anodised in the H3PO4, which consisted of a thinner TiO2 anodised film. SEM images demonstrated that H2SO4 resulted in arcing and resultant porosity while H3PO4 did not. Profilometry revealed that the former was rougher than the latter and that the latter was nearly the same roughness as the sand-blasted plate. These observations are consistent with the conclusion that H3PO4 formed a thinner anodised film and that the greater thickness from H2SO4 resulted in asperity formation, which enhanced arcing and densification. Although the anatase-rutile mixture and the greater roughness of the sample anodised in H2SO4 could be expected to have yielded superior performance, the fact that it did not is attributed to the greater bulk density and associated lower surface area of the TiO2 matrix. Preliminary cell culture tests showed that human osteoblast-like cells (MG63) were attached effectively on smooth anodised films (on polished plates) after 4 h of incubation while cell proliferation was confluent after 2 days. The major finding of the present work is that X-radiation in clinical doses (<200 cGy) is sufficient to cause degradation of organic species via photocatalysis.
Z-Scheme over all Water Splitting on Rh/K4Nb6O17 Nanosheets Photocatalyst
Authors: Lin Hsin Yu , Ye Yu Lin
Published: October 2016

Developing a photocatalysis system to generate hydrogen from water is a topic of great interest for fundamental and practical importance. In this study, hydrogen production by a new Z-scheme photocatalysis water splitting system was examined over Rh modified K4Nb6O17 nanosheets and Pt/WO3 photocatalysts for H2 evolution and O2 evolution with I-/IO3- electron mediator under UV light irradiation. The H2 evolution photocatalyst, Rh/K4Nb6O17 nanosheets with a slit like framework, was prepared by exfoliation of and proton exchange reaction. Pt/WO3 prepared by incipient-wetness impregnation method was used as O2 evolution photocatalyst. The catalysts were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy analysis (XPS), and ultraviolet-visible spectroscopy (UV-vis). These catalysts characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectroscopy (UV-Vis). In this study, we developed a facile method of preparing K4Nb6O17 nanosheets containing Rh nanoparticles. Our results show that I- concentration and pH of reaction solution significantly influenced the photocatalytic activity. The combination of Rh modified K4Nb6O17 nanosheets with Pt/WO3 achieves a very high photoactivity (H2: 4240 O2: 1622 (μmol g-1 h-1)).
Enhanced Gas Sensing Properties of Different ZnO 3D Hierarchical Structures
Authors: Fioravanti Ambra , Bonanno Antonino , Mazzocchi Mauro , Carotta Maria Cristina , Sacerdoti Michele
Published: October 2016

Six different ZnO nanomorphologies were synthesized trough wet chemical routes starting from a water solution of zinc nitrate hexahydrate, obtaining two types of morphologies: bidimensional nanocrystals and nanoparticles aggregates. Powders and films characterizations have been carried out by means of TG–DTA, SEM, and X-ray diffraction analysis. Finally, electrical measurements were performed with the aim to compare conductive properties of the thick films, surface barrier heights and gas sensing features, mainly versus acetone and other VOCs related to the breath gas analysis. Among the different morphologies tested, it turned out that the samples constituted by nanoparticle aggregates exhibited the best performances versus all gases, but especially toward acetone at sub-ppm level.
The Resistive Switching Behavior of ZnO Films Depending on Li Dopant Concentration and Electrode Materials
Authors: Igityan Arsen , Kafadaryan Yevgenia , Aghamalyan Natella , Petrosyan Silva
Published: October 2016

Lithium (0, 1.0 and 10 at.%)-doped ZnO (LiZnO) polycrystalline thin films were deposited on Pt/SiO2, LaB6/Al2O3, Au/SiO2 and 20 at.% fluorine-doped SnO2(FTO)/glass substrates by an e-beam evaporation method. Metal/LiZnO/Metal sandwich structures were constructed by depositing different top electrodes (Ag, Al and Au) to find memristive characteristics depending on the lithium content and electrode materials. Compared with undoped and 1%Li-doped ZnO devices, the 10 at.%Li-doped ZnO (10LiZnO) device exhibits resistive switching memory. The Ag/10LiZnO/Pt and Ag/10LiZnO/LaB6 memory devices exhibit unipolar resistive switching behavior while bipolar resistive switching in Ag/10LiZnO/FTO, Au/10LiZnO/FTO and Al/10LiZnO/LaB6 structures is revealed. The dominant conduction mechanisms are explained in terms of Ohmic behavior, space charge limited current (SCLC) and Schottky emission for the URS and BRS behaviors.
Ion Selection by Redox Changes in a Soluble Helical Polythiophene Channel
Authors: Morton-Blake D.A.
Published: October 2016

Molecular dynamics are applied to simulate molecular motions in an aqueous solution of two soluble derivatives of a 100-ring polythiophene chain – one with sidechains terminating in a SO3– group, the other in NMe3+. Each chain is in a helical conformation defining a water-containing central channel along whose axis the dynamics of ions from the solution to the channel’s axial electrostatic potential is simulated. The profiles of these potentials distinguish the tendencies of the two channel species to occlude water molecules on their surfaces. Invoking the conductive polymer characteristics of polythiophene that can accomplish the transfer of electrons between the aromatic rings and redox reagents in the solution, the effect of this transfer on the axial potential and migration is followed. The electrostatic potential monitors differences in the association of the solvent molecules with the two species of helical polymer and shows that while Na+ and Cl– ions do not enter the channel in the absence of the redox changes, an ion with a selected charge does so spontaneously when appropriate electric charge is transferred to the channel. This enables the selected ion to travel about 10 – 20Å in the channel without the application of an external electric field.
Molecular Dynamics Study of Mass Transport Properties of Liquid Cu-Ag Alloys
Authors: Sarder U. , Evteev Alexander V. , Levchenko Elena V. , Kromik A. , Belova I.V. , Murch Graeme E.
Published: October 2016

In this study, mass transport properties of liquid Cu-Ag alloys are investigated over wide temperature and composition ranges. The calculations are performed within the framework of the Green-Kubo (GK) formalism by using equilibrium molecular dynamics (MD) simulations along with one of the most reliable embedded-atom method potentials for this system developed by [P. Williams et al.: Modell. Simul. Mater. Sci. Eng. vol. 14 (2006), p. 817]. The approach employed allows for evaluation of the components’ self-diffusion coefficients as well as the phenomenological coefficient for mass transport Lcc. The results obtained in this study can be used to predict the kinetics of solidification of real liquid Cu-Ag alloys.
Thermal Decomposition of Supersaturated Ti1-xAlxN Solid Solution Synthesized by High-Energy Milling
Authors: Radune Maya , Zinigrad Michael , Fuks David , Hayun S. , Frage Nachum
Published: October 2016

Supersaturated titanium-aluminum nitride (Ti1-xAlxN) is a very attractive material for a wide range of applications due to its high oxidation and wear resistance accompanied by high strength, hardness, thermal conductivity and thermal shock resistance. Currently, its applications are limited to coatings obtained by physical or chemical deposition. Bulk materials based on Ti1-xAlxN may be fabricated by powder metallurgy approach using powders synthesized by high-energy ball milling (HEBM), which composition corresponds to supersaturated Ti1-xAlxN solid solution. In the present study, thermal stability of the supersaturated Ti1-xAlxN solid solution was investigated. According to the quasi-binary TiN-AlN phase diagram, constructed using density functional theory (DFT) analysis, the concentration ranges, where decomposition takes place through spinodal decomposition or through nucleation and growth, were determined. Experimental study on thermal stability of solid Ti1-xAlxN solution powder was conducted by means of differential scanning calorimetry (DSC), Brunauer-Emmited-Teller (BET) and XRD. The results indicated that spinodal decomposition of Ti1-xAlxN starts at 800°C, while at temperature higher than 1300°C regular decomposition (nucleation and growth) is occur.
Peculiarities of the Gingiva Cellular Composition and Functional Activity of the Epithelial Cells among the Children Patients with Chronic Gastritis and Duodenitis
Authors: Romanenko Y.G. , Matveeva A.D.
Published: October 2016

At the children with chronic gastritis and duodenitis was revealed destroyed of morphological - functional property of gums with prevalence of degenerative component, which is manifested by appearance of basal and parabasal cells (0.3%), increasing of intermediate epithelial cells (84.7%), decreasing amount of surface nucleated epithelial cells (11.7%), and nuclear-free dead skin cells (4.3%). Majority of cells was with cytopathology shifts (18.2%), polymorphonuclear leukocytes (92.3%) and lymphocytes (20.5%). The data obtained in the research showed that 23 (21.5%) of samples, taken from children with chronic gastritis and duodenitis revealed cells in the early stages of differentiation, accumulation of leukocytes and fibrin, which demonstrates erosions of the gums in the epithelial layer. Adhesion of epithelial cells with Candida albicans at the children with chronic gastritis and duodenitis indicates about changes functional properties of the epithelial cells, growing on a background of the somatic pathology.
Surface EMG Based Muscle Fatigue Evaluation on Neck-Shoulder Muscles while Using Single-Monitor Arm
Authors: Shao Yan Hao , Zhou Yan Song , Zhang Yan , Gu Yao Dong , Fekete Gusztáv , Fernandez Justin
Published: October 2016

The median frequency (MF) and mean power frequency (MPF) have been confirmed as reliable indicators of muscle fatigue during sustained contractions. The purpose of this study was to explore whether single-monitor arm could release muscle fatigue in neck-shoulder region while maintaining a prolonged seated posture viewing computer screen by measuring MF and MPF. Ten male healthy university students volunteered to participate in the test. Surface electromyography of splenius capitis (SC) and trapezius (TR) were recorded. Each subject performed normal text editing tasks or video watching activities for 120 minutes with different monitor arm positions (Fixed, moving downward and moving upward). Results showed that the MPF of SC and TR had significant decreased trend as monitor arm at fixed position. As monitor arm moving upward, the MF and MPF of both muscles decreased significantly with time and the MF showed the lowest decline rate during the entire testing process. No significant shift of MF and MPF were observed as monitor arm moving downward. Findings of this study may have important implications for people who use computer intensively to release neck-shoulder muscle fatigue.
Stepwise approach for implementation of antimicrobial resistance surveillance in Africa
Authors: Perovic Olga , Schultsz Constance
Published: October 2016

Background: Antimicrobial resistance (AMR) has reached an end point, prompting a worldwide scare as no new antibiotics are in the pipeline, particularly for treatment of Gram-negative bacteria. To prevent further development and spread of AMR and to inform empirical treatment guidelines, surveillance of AMR is necessary.Objective: We aim to provide a framework for a stepwise approach toward implementation of laboratory-based surveillance for AMR in African countries.Methods and Results: Building up a surveillance system is a robust process that begins with a gap analysis in each participating country. This framework provides practical guidance on how to set up surveillance, identify responsibilities and set timelines in sustainable manner for African countries. It addresses sampling strategies, human resources, procurement and maintenance issues for AMR testing at routine clinical and national reference and public health laboratories involved in AMR surveillance. Key issues such as laboratory capacity building, training and continuous education, quality and diagnostic stewardship are discussed in detail.Discussion: There are several priorities for AMR surveillance that need to be addressed in a comprehensive manner at regional and national levels, whilst keeping in line with current and proposed initiatives for laboratory capacity building, in order for African countries to achieve goals for combatting the real and current threat of AMR.
Laboratory systems as an antibacterial resistance containment tool in Africa
Authors: Okeke Iruka N.
Published: October 2016

Introduction: As crucial as clinical laboratories are to preventing, identifying and managing resistance problems, laboratory scientists are among the most overlooked stakeholders. This review outlines the contributions that diagnostic laboratory systems should make toward all five of the World Health Organization’s 2015 strategic objectives for antimicrobial resistance containment.Laboratory systems in resistance containment: Antimicrobial susceptibility testing and surveillance are central to antibacterial resistance management and control and need to be implemented more commonly and closer to sick patients. However, the scope of tests that promote judicious antimicrobial use extend beyond susceptibility testing. Laboratory tests for pathogens or their associated biomarkers confirm or rule out specific causes of signs and symptoms associated with infection. Laboratory systems also provide critical support to infection control programmes. All of these functions promote rational antimicrobial use and contain the spread of resistance. Routine laboratory data supports the development of vaccines and other technologies that could ease the pressure placed by antimicrobials. Laboratories are also a rich source of information for health professionals, policymakers and the general public about the urgency of the resistance problem and progress in containing it.Conclusion: Laboratory systems are integral to antimicrobial resistance containment and contributions from African laboratories to addressing resistance need to be enhanced.
The laboratory health system and its response to the Ebola virus disease outbreak in Liberia
Authors: Kennedy Stephen B. , Wasunna Christine L. , Dogba John B. , Sahr Philip , Eastman Candace B. , Bolay Fatorma K. , Mason Gloria T. , Kieh Mark W.S.
Published: October 2016

The laboratory system in Liberia has generally been fragmented and uncoordinatedAccordingly, the country’s Ministry of Health established the National Reference Laboratoryto strengthen and sustain laboratory services. However, diagnostic testing services were oftenlimited to clinical tests performed in health facilities, with the functionality of the NationaReference Laboratory restricted to performing testing services for a limited number ofepidemic-prone diseases. The lack of testing capacity in-country for Lassa fever and otherhaemorrhagic fevers affected the response of the country’s health system during the onset ofthe Ebola virus disease (EVD) outbreak. Based on the experiences of the EVD outbreak, effortswere initiated to strengthen the laboratory system and infrastructure, enhance human resourcecapacity, and invest in diagnostic services and public health surveillance to inform admittancetreatment, and discharge decisions. In this article, we briefly describe the pre-EVD laboratorycapability in Liberia, and extensively explore the post-EVD strengthening initiatives to enhancecapacity, mobilise resources and coordinate disaster response with international partners torebuild the laboratory infrastructure in the country. Now that the EVD outbreak has endedadditional initiatives are needed to revise the laboratory strategic and operational plan forpost-EVD relevance, promote continual human resource capacity, institute accreditation andvalidation programmes, and coordinate the investment strategy to strengthen and sustain thepreparedness of the laboratory sector to mitigate future emerging and re-emerging infectiousdiseases.
‘Doing Justice’ (משפט בעושי) to the Dead Sea Scrolls: Reading 1QS 8:1–4 in literary and sectarian context
Authors: Howes Llewellyn
Published: October 2016

Within the Community Rule, 1QS 8:1–4 has at times been used as an intertext to support claims pertaining to the future expectations of both early Jesus movements and the historical Jesus himself. In particular, the passage has functioned as an intertext to support the notion that Jesus and some of his earliest movements foresaw the future restoration and liberation of greater Israel in toto, including outsiders. Without getting involved in this larger New Testament debate, the current article wishes to address the appropriateness of using 1QS 8:1–4 as an intertext without taking its literary and sectarian contexts into consideration. Focusing throughout on the interrelationship between judgement and boundary demarcation, this article will unfold in a centripetal manner. Firstly, it will treat the commonalities among all the sectarian Dead Sea Scrolls. Secondly, the discussion will direct its focus specifically to the Community Rule. Finally, we will look at 1QS 8:1–4 in particular.
Exposing the profiteers of globalisation, disaster, conflict and detention
Authors: Von Meding Jason K.
Published: October 2016

No abstract available
Eco-epidemiological and pathological features of wildlife mortality events related to cyanobacterial bio-intoxication in the Kruger National Park, South Africa
Authors: Bengis Roy , Govender Danny , Lane Emily , Myburgh Jan , Oberholster Paul , Buss Peter , Prozesky Leon , Keet Dewald
Published: October 2016

Over the past decade, several clustered, multispecies, wildlife mortality events occurred in the vicinity of two man-made earthen dams in the southern and south central regions of the Kruger National Park, South Africa. On field investigation, heavy cyanobacterial blooms were visible in these impoundments and analysis of water samples showed the dominance of Microcystis spp. (probably Microcystis aeruginosa). Macroscopic lesions seen at necropsy and histopathological lesions were compatible with a diagnosis of cyanobacterial intoxication. Laboratory toxicity tests and assays also confirmed the presence of significant levels of microcystins in water from the two dams. These outbreaks occurred during the dry autumn and early winter seasons when water levels in these dams were dropping, and a common feature was that all the affected dams were supporting a large number of hippopotamuses (Hippopotamus amphibius). It is hypothesised that hippopotamus’ urine and faeces, together with agitation of the sediments, significantly contributed to internal loading of phosphates and nitrogen – leading to eutrophication of the water in these impoundments and subsequent cyanobacterial blooms. A major cause for concern was that a number of white rhinoceros (Ceratotherium simum) were amongst the victims of these bio-intoxication events. This publication discusses the eco-epidemiology and pathology of these clustered mortalities, as well as the management options considered and eventually used to address the problem.
Bridging the knowing–doing gap in South Africa and the role of environmental volunteer groups
Authors: Dzerefos Cathy M. , Witkowski Ed T.F.
Published: October 2016

The implementation gap between science, policy and practice has led to loss of biodiversity and ecosystem services throughout Africa and is described in a case study from Limpopo Province, South Africa. In 2006, the South African National Biodiversity Institute first highlighted the Woodbush Granite Grassland (WGG) in the Greater Tzaneen Local Municipality as the only Critically Endangered ecosystem in Limpopo Province. Five years later (2011), the Critically Endangered listing was published in the Government Gazette No. 34809. After repeated and sustained efforts for many years from volunteers of a local environmental group – currently known as the Friends of the Haenertsburg Grassland (FroHG) – in 2015 the intent to formally protect 126 ha was published in the Government Gazette No. 2609. Unfortunately, the proposed protected area accounts for only 66% of the largest remaining fragment of WGG, which excludes an important colony of medicinal plants. Considering that only 6% of the original extent of WGG remains in an untransformed state the whole fragment should be conserved. Non-alignment of municipal spatial priorities, as in the Haenertsburg town plan from 1896, to provincial and national environmental priorities has resulted in numerous incidents that have degraded what little remains of the WGG ecosystem. Failure of the provincial authorities to act timeously to enforce environmental regulations resulted in the FroHG successfully involving national authorities to stop illegal land occupation while another incident involving an illegal fence was resolved 9 years after erection. A strengthened relationship with Lepelle Northern Water has resulted in better planning of activities in relation to an existing pipeline. This case study shows various avenues available to environmental volunteer groups in South Africa and suggests that long-term lobbying can yield positive results.Conservation implications: Formal conservation of WGG through the intended nature reserve proclamation represents application of environmental legislation (notably Listing Notice 3, National Environmental Management Act 107 of 1998: Environmental Impact Assessment Regulations, 2014), scientific recommendations and policy. Better cooperation between provincial administration and FroHG will benefit the protection and management of WGG.
Indlela or uhambo? Translator style in Mandela’s autobiography
Authors: Nokele Amanda , Moropa Koliswa
Published: October 2016

One of the aspects that concerns translation scholars most is the question of the translator’s style. It was realised that little research had been undertaken investigating the individual style of literary translators in terms of what might be distinct about their language usage. Consequently, a methodological framework for such an investigation was suggested. Subsequently considerable research has been conducted on style in the European languages. However, the same cannot be said about African languages. This article proposes a corpus-driven study of translators’ style, comparing isiXhosa and isiZulu translations of Mandela’s Long Walk to Freedom by Mtuze and Ntuli, both published in 2001. The target texts are compared with each other focusing on the use of italics, loan words and expansions and contractions as features that distinguish the two translators. The source text was used not to evaluate the target texts but to understand the translators’ choices. ParaConc Multilingual Concordancer was used to align the source text and its target texts for easy examination. The results revealed that the fact that the two translators were dealing with an autobiography did not deter them from displaying their personal imprints as creative writers.
Perception of performance management system by academic staff in an open distance learning higher education environment
Authors: Maimela Esther M. , Samuel Michael O.
Published: October 2016

Orientation: Institutions of higher learning in South Africa are fast embracing performance management system (PMS) as a mechanism for the achievement of teaching excellence and enhancement of research productivity. However, literature provided evidence to show that application of PMS in the private sector had failed to drive competition, efficiency and productivity.Research purpose: The main purpose of this article was to evaluate the perception of academic staff members of an open distance learning institution regarding the implementation of a PMS.Motivation for the study: PMS as a mechanism through which performance of academics is measured has been described as inconsistent with the long tradition of academic freedom, scholarship and collegiality in the academy. Moreso, previous research on the implementation of PMS was limited to private sector organisations, thus resulting in the dearth of empirical literature relating to its practice in service-driven public sector institutions.Research design, approach and method: The article adopted a quantitative research approach using census survey methodology. Data were collected from 492 academic staff from the surveyed institution using a self-developed questionnaire that was tested for high content validity with a consolidated Cronbach’s alpha value of 0.83. Data were analysed using a onesample t-test because of the one-measurement nature of the variable under investigation.Main findings: Major findings of the study indicated that respondents were satisfied with the implementation of the PMS by management. However, the payment of performance bonuses was not considered as sufficiently motivating, thus necessitating a pragmatic review by management.Practical/managerial implications: The findings of this article provided a practical guide to managers on the implementation and management of PMS as an employee performance reward mechanism in non-profit and service-oriented organisations.Contribution: This article provided an incremental contribution to the body of literature in the broad field of management and a further advancement of existing knowledge in the sub-field of performance management system.