bluuebunny/crossref_metadata_2025 huggingface dataset:
Photo-Electrochemical Etching in the Process of Direct H2 Generation by Illumination of GaN-Based Material Structures Immersed in Water
Authors: Usikov A. , Luryi S. , Nikiforov A. , Helava H. , Makarov Yu. , Gouzman M.
Published: December 2016

Hydrogen is considered a promising candidate for energy storage. We investigated the cleanest way for hydrogen production by direct photo electrolysis of water with GaN/AlGaN based p-n structures used as working electrodes. Besides the H2 production rate, an important consideration is the material etching (corrosion) that accompanies the photo-electrochemical process. The GaN-based structures were grown on sapphire substrates by the chloride hydride vapor phase epitaxy and used as a photo anode immersed into an aqueous electrolyte. For a p-n GaN/AlGaN structure we observed a H2 production rate of 0.6 mL/cm2×h. Corrosion of the electrode proceeds in two steps. First, there is a near vertical etching process, which is associated with defects in the material and penetrates deep into the structure. Subsequently, the process involves etching of n-type layers in lateral direction resulting in the formation of voids and cavities. The lateral etching is due to net positive charges arising from the spontaneous and piezoelectric polarization in the structure and positively charged ionized donors in the space charge region of the p-n junction.
Cosmological aspects of a unified dark energy and dust dark matter model
Authors: Staicova Denitsa , Stoilov Michail
Published: December 2016

Recently, a model of modified gravity plus single scalar field was proposed, in which the scalar couples both to the standard Riemannian volume form given by the square root of the determinant of the Riemannian metric, as well as to another non-Riemannian volume form given in terms of an auxiliary maximal rank antisymmetric tensor gauge field. This model provides an exact unified description of both dark energy (via dynamically generated cosmological constant) and dark matter (as a “dust” fluid due to a hidden nonlinear Noether symmetry).

In this paper, we test the model against Supernovae type Ia experimental data and investigate the future Universe evolution which follows from it. Our results show that this model has very interesting features allowing various scenarios of Universe evolution and in the same time perfectly fits contemporary observational data. It can describe exponentially expanding or finite expanding Universe and moreover, a Universe with phase transition of first kind. The phase transition occurs to a new, emerging at some time ground state with lower energy density, which affects significantly the Universe evolution.
Crystalline phase transformation of colloidal cadmium sulfide nanocrystals
Authors: Ghali M. , Eissa A. M. , Mosaad M. M.
Published: December 2016

In this paper, we give a microscopic view concerning influence of the growth conditions on the physical properties of nanocrystals (NCs) thin films made of CdS, prepared using chemical bath deposition CBD technique. We show a crystalline phase transformation of CdS NCs from hexagonal wurtzite (W) structure to cubic zincblende (ZB) when the growth conditions change, particularly the solution pH values. This effect was confirmed using X-ray diffraction (XRD), transmission electron microscopy (TEM), optical absorption and photoluminescence (PL) measurements. The optical absorption spectra allow calculation of the bandgap value, [Formula: see text], where significant increase [Formula: see text]200 meV in the CdS bandgap when transforming from Hexagonal to Cubic phase was found.
Mixed magnetic exchange interactions and ferromagnetic diffuse phase transition of La1−xMnO3+δ manganites
Authors: Zhang W. C. , Zhang A. M. , Zhang X. , Zhou G. T. , Wu X. S.
Published: December 2016

Effects of vacancy on the microstructural and magnetic properties in self-doped La[Formula: see text]MnO[Formula: see text] [Formula: see text] manganites have been studied. The samples crystallize in a single phase of rhombohedral structure exhibiting R[Formula: see text]C space group until [Formula: see text]-value reaches 0.2. As self-doped concentration increases, structural distortion is confirmed by combining X-ray diffraction. Ferromagnetic (FM) and antiferromagnetic (AFM) coupling is found and exchange bias effect appears at low temperature. Ferromagnetic diffuse phase transition (FDPT) is induced by Griffiths phase for [Formula: see text] at temperature of [Formula: see text]. The FM transition temperature range is increased from 32 K to 150 K. The enhancement of Griffiths phase with [Formula: see text] for [Formula: see text] is explained by the greater [Formula: see text]-site spatial disorder and the structural distortion.
Ferroelectric properties in all solution prepared Bi6Fe2Ti3O18/Ba0.92La0.08SnO3 thin films
Authors: Zhang Li , Li Yibao , Tang Zhen , Deng Yan , Yuan Hui , Yu Jiangying , Zhu Xuebin
Published: December 2016

In this paper, all solution processing is used to prepare both the transparent conducting Ba[Formula: see text]La[Formula: see text]SnO3 (BLSO) thin films as bottom electrodes and ferroelectric Bi6Fe2Ti3O[Formula: see text] (BFTO) thin films. The derived BFTO thin films are characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The derived thin film is polycrystalline with dense microstructures. The remnant polarization [Formula: see text] at the measurement frequency of 2 kHz can reach [Formula: see text] under the 500 kV/cm electric field and the coercive field [Formula: see text] is 410 kV/cm. The results will provide a feasible route to prepare BFTO thin films on transparent conducting bottom electrodes to realize multifunctionality.
PERCOLATION LAWS OF A FRACTAL FRACTURE-PORE DOUBLE MEDIUM
Authors: ZHAO YANGSHENG , FENG ZENGCHAO , LV ZHAOXING , ZHAO DONG , LIANG WEIGUO
Published: December 2016

The fracture-pore double porosity medium is one of the most common media in nature, for example, rock mass in strata. Fracture has a more significant effect on fluid flow than a pore in a fracture-pore double porosity medium. Hence, the fracture effect on percolation should be considered when studying the percolation phenomenon in porous media. In this paper, based on the fractal distribution law, three-dimensional (3D) fracture surfaces, and two-dimensional (2D) fracture traces in rock mass, the locations of fracture surfaces or traces are determined using a random function of uniform distribution. Pores are superimposed to build a fractal fracture-pore double medium. Numerical experiments were performed to show percolation phenomena in the fracture-pore double medium. The percolation threshold can be determined from three independent variables (porosity [Formula: see text], fracture fractal dimension [Formula: see text], and initial value of fracture number [Formula: see text]). Once any two are determined, the percolation probability exists at a critical point with the remaining parameter changing. When the initial value of the fracture number is greater than zero, the percolation threshold in the fracture-pore medium is much smaller than that in a pore medium. When the fracture number equals zero, the fracture-pore medium degenerates to a pore medium, and both percolation thresholds are the same.
Visual Grasp Affordance Localization in Point Clouds Using Curved Contact Patches
Authors: Kanoulas Dimitrios , Lee Jinoh , Caldwell Darwin G. , Tsagarakis Nikos G.
Published: December 2016

Detecting affordances on objects is one of the main open problems in robotic manipulation. This paper presents a new method to represent and localize grasp affordances as bounded curved contact patches (paraboloids) of the size of the robotic hand. In particular, given a three-dimensional (3D) point cloud from a range sensor, a set of potential grasps is localized on a detected object by a fast contact patch fitting and validation process. For the object detection, three standard methods from the literature are used and compared. The potential grasps on the object are then refined to a single affordance using their shape (size and curvature) and pose (reachability and minimum torque effort) properties, with respect to the robot and the manipulation task. We apply the proposed method to a circular valve turning task, verifying the ability to accurately and rapidly localize grasp affordances, under significant uncertainty in the environment. We experimentally validate the method with the humanoid robot COMAN on 10 circular control valves fixed on a wall, from five different viewpoints and robot poses for each valve. We compare the reliability of the introduced local grasp affordances method to the baseline that relies only on object detection, illustrating the superiority of ours for the valve turning task.
Translated points on hypertight contact manifolds
Authors: Meiwes Matthias , Naef Kathrin
Published: December 2016

A contact manifold admitting a supporting contact form without contractible Reeb orbits is called hypertight. In this paper we construct a Rabinowitz–Floer homology associated to an arbitrary supporting contact form for a hypertight contact manifold [Formula: see text], and use this to prove versions of a conjecture of Sandon [17] on the existence of translated points and to show that positive loops of contactomorphisms give rise to non-contractible Reeb orbits.
Highway Dimension and Provably Efficient Shortest Path Algorithms
Authors: Abraham Ittai , Delling Daniel , Fiat Amos , Goldberg Andrew V. , Werneck Renato F.
Published: December 2016

Computing driving directions has motivated many shortest path algorithms based on preprocessing. Given a graph, the preprocessing stage computes a modest amount of auxiliary data, which is then used to speed up online queries. In practice, the best algorithms have storage overhead comparable to the graph size and answer queries very fast, while examining a small fraction of the graph. In this article, we complement the experimental evidence with the first rigorous proofs of efficiency for some of the speedup techniques developed over the past decade or variations thereof. We define highway dimension, which strengthens the notion of doubling dimension. Under the assumption that the highway dimension is low (at most polylogarithmic in the graph size), we show that, for some algorithms or their variants, preprocessing can be implemented in polynomial time, the resulting auxiliary data increases the storage requirements by a polylogarithmic factor, and queries run in polylogarithmic time. This gives a unified explanation for the performance of several seemingly different approaches. Our best bounds are based on a result that may be of independent interest: we show that unique shortest paths induce set systems of low VC-dimension, which makes them combinatorially simple.
Impulse Diagnostic Test of Battery and Load Influence
Authors: Reichl Tomáš , Hrzina Pavel
Published: December 2016

For power source diagnostics and lifetime prediction, it is necessary to define the major processes which influence the source’s behaviour in the most significant way. The first process is connected with the internal resistance (Ri) of electrochemical source (ES) which influence the voltage decrease of source’s voltage course. The second substantial process in electrochemical conversion is the diffusion process. This process dominates when the pulsed load is applied where it influences the source’s capacity and can be evaluated using the impulse measurement methods, where internal resistance and diffusion process are evaluated simultaneously.
Li-Ion Battery Deep Discharge Degradation
Authors: Prochazka Petr , Cervinka Dalibor , Martis Jan , Cipin Radoslav , Vorel Pavel
Published: December 2016

Deep discharging or over-charging of Li-ion cells must be avoided to ensure sufficient life-time and sometimes also the operation safety of these batteries. BMS circuits co-operating with the charger and forbidding deep discharging of the cells are necessarily present in battery packs. However, deep discharging can appear in a case of BMS failure or poor user care of the batteries. Then the battery can be discharged to zero voltage. Battery manufacturers do not allow such operation and battery behavior in this situation is not described in their datasheets. Experimental deep discharging was performed. After discharging, the battery was left in a fully discharged state (zero voltage) for various time intervals before it was fully recharged again. Consequently, capacity decrease or internal resistance increase was checked.
Pulse Power Capability Estimation of Lithium Titanate Oxide-Based Batteries
Authors: Stroe Ana-Irina , Swierczynski Maciej , Stroe Daniel Ioan , Teodorescu Remus , Kær Søren Knudsen
Published: December 2016

The pulse power capability (PPC) represents one of the parameters that describe the performance behavior of Lithium-ion batteries independent on the application. Consequently, extended information about the Li-ion battery PPC and its dependence on the operating conditions become necessary. Thus, this paper analyzes the power capability characteristic of a 13Ah high power Lithium Titanate Oxide-based battery and its dependence on temperature, load current and state-of-charge. Furthermore, a model to predict the discharging PPC of the battery cell at different temperatures and load currents for three different state-of-charge levels was proposed and parameterized.
FEM Model of the Lithium Ion Battery Nail Test
Authors: Vyroubal Petr , Kazda Tomáš , Bayer Robert
Published: December 2016

Internal short-circuit is the most dangerous abusive condition for Li-ion batteries and has been the root cause for several catastrophic accidents involving Li-ion batteries in recent years. Large-format Li-ion batteries are particularly vulnerable to internal short-circuits because of high energy content. Nail penetration test is commonly used to study the internal short-circuits, but the test results usually have poor reproducibility and offer limited insight. This paper deals with a possibility of numerical simulation of internal short circuit test using FEM.
Significance of the Capacity Recovery Effect in Pouch Lithium-Sulfur Battery Cells
Authors: Knap Vaclav , Zhang Teng , Stroe Daniel Ioan , Schaltz Erik , Teodorescu Remus , Propp Karsten
Published: December 2016

Lithium-Sulfur (Li-S) batteries are an emerging energy storage technology, which is technically-attractive due to its high theoretical limits; practically, it is expected that Li-S batteries will result into lighter energy storage devices with higher capacities than traditional Lithium-ion batteries. One of the actual disadvantages for this technology is the highly pronounced rate capacity effect, which reduces the available capacity to be discharged when high currents are used. This drawback might be addressed by the use of the capacity recovery effect, which by introducing relaxation periods between consecutive pulse discharges of the battery, increases the available discharge capacity of the cell. The capacity recovery effect of the Li-S cell is studied in this paper using the pulse discharge technique, considering its dependence on the applied current, discharge step length, temperature, and on the length of the relaxation period between the discharging pulses.
Design, Build and Validation of a Low-Cost Programmable Battery Cycler
Authors: Propp Karsten , Fotouhi Abbas , Knap Vaclav , Auger Daniel J
Published: December 2016

The availability of laboratory grade equipment for battery tests is usually limited due to high costs of the hardware. Especially for lithium-sulfur (Li-S) batteries these experiments can be time intensive since the cells need to be precycled and are usually cycled with relatively low loads. To improve the availability of test hardware, this paper conducts a study to design and test a low cost solution for cycling and testing batteries for tasks that do not necessarily need the high precision of professional hardware. While the described solution is in principle independent of the cell chemistry, here it is specifically optimized to fit to Li-S batteries. To evaluate the accuracy of the presented battery cycler, the hardware is tested and compared with a professional Kepco bipolar power source. The results indicate the usefulness for application oriented battery tests with real life cycles, although inaccuracies occur in the current measurements.
Curing of Positive Electrode Mass of Lead Acid Battery Studied by XRD
Authors: Cech Ondrej , Zimáková Jana , Vaculík Sebastian , Vanýsek Petr , Chladil Ladislav , Křivík Petr , Čudek Pavel , Bača Petr
Published: December 2016

In this work, XRD characterization of prepared lead-acid battery positive electrode mixture was performed in respect to crystallographic changes after curing. The main aim of this contribution is to describe the crystallographic composition and properties of the cured electrode mass together with characterization of composition and crystallinity of starting precursors.
XRD Study of Lead Sulphate Crystal Growth in a Sulphuric Acid Solution
Authors: Chladil Ladislav , Cech Ondrej , Vanýsek Petr
Published: December 2016

Layer of lead sulfate was prepared by anodic oxidation of a lead metal surface under potential 0.0 V vs. mercury sulfate reference electrode. Gradual evolution of a lead sulfate layer during lead oxidation in sulfuric acid environment was investigated by SEM and XRD method. We observed gradual inhibition of the lead sulfate layer during oxidation. Investigation of particle size by the Halder-Wagner analysis method during oxidation revealed a significant increase in particle (crystallite) size mainly during the second part of the oxidation process. The parameters were confirmed by morphology evaluation of images from the scanning electron microscope. Powder XRD device seems to be a useful tool for lead sulfate particle size investigation and measurement of their evolution throughout the lead-acid battery life span.
PMMA-Based Electrolytes for Li-Ion Batteries
Authors: Jahn Michal , Sedlaříková Marie , Vondrák Jiří , Pařízek Ladislav
Published: December 2016

Currently, the most used electrochemical power sources are Li-ion accumulators due to their high theoretical capacity and work potential. Because of increasing demands (current density and capacity), new forms of electrode materials and electrolytes for electrochemical power sources are researched. Gel polymer electrolytes are perspective for new types of Li-ion batteries. The properties and advantages of these gels can be used also in other fields of electrochemistry. The gel polymer electrolyte is composed of a conductive component (liquid electrolyte) and a polymer component (methacrylate). In this paper, we present fundamental characteristics of gel polymer electrolytes based on methacrylate.
Rate Capability of Graphite Negative Electrode in Lithium-Ion Cell
Authors: Libich Jiri , Maca Josef , Sedlarikova Marie , Vondrák Jiří , Cech Ondrej
Published: December 2016

This paper describes experiments which show the difference of lithiated graphite material in contrast with common graphite material. The charge-discharge characteristics and capacity of negative electrode material based on graphite were main aspects of our investigation. Along with capacity the rate-capability as negative electrode property was examined. The rate-capacity property depends primarily on the kinetic abilities of electrode i.e. ability to release lithium ions during discharge extraction from electrode. In our work, the natural graphite was used as active electrode material. The various rate-capability tests were investigated.
High Voltage Materials for Lithium-Ion Accumulators
Authors: Tichy Jiri , Kazda Tomáš , Sedlarikova Marie , Čudek Pavel
Published: December 2016

The aim of this work was to synthesize material for the positive electrode of lithium accumulators, to characterize the material, to prepare test electrodes with this material, and to measure their characteristics. The main material researched in this work is LiNi0,5Mn1,5O4. This material should ensure higher voltage of lithium cells; reaching up to 5 V. Preparation of the material was done by solid state synthesis method.
Influence of the Annealing Temperature to the Properties of LiNi0.5Mn1.5O4 High Voltage Spinel Cathode for Li-Ion Batteries
Authors: Kazda Tomáš , Vondrák Jiří , Sedlarikova Marie , Tichý Jiří , Čudek Pavel
Published: December 2016

High voltage cathode materials are one of the most promising ways for the next generation of cathode materials for the lithium-ion batteries. Thanks to their high potential and capacity comparable with standard cathode materials as LiCoO2 or LiFePO4, they can reach much higher gravimetric energy density. As for any other cathode material, good crystallinity after synthesis is also very important for high voltage materials to reach a good electrochemical performance during cycling. This paper deals with the influence of annealing temperature on electrochemical properties of high voltage spinel cathode LiNi0.5Mn1.5O4. It was studied at three different temperatures of the synthesis in terms of electrochemistry and structure by SEM and in term of electrochemistry by cycling at different C-rate.
Rheological Properties of Heat Transfer Liquids for Solar Thermal Systems
Authors: Frk Martin , Hylský Josef , Strachala David
Published: December 2016

This article discusses the rheological properties of heat transfer fluids used in all year round solar systems. Four commercially known media were measured. Two of them were glycols based media and two of them alternative heat transfer fluids based on glycerol. Parameters of viscosity and density were measured in a wide range of temperature. Measured dependencies were mathematically approximated by Vogel-Fulcher-Tammanovou equation that very accurately describes their shape. The temperature coefficient of volumetric expansion β is another parameter of heat-transfer fluids described in this article. β plays a very important role in the construction of the solar system. The last parameter determining the year round operation is the freezing point. Freezing point was measured by the cryoscopic methods.
The Capacitive Performance of α-Ni(OH)2-Based Composites for Hybrid Supercapacitors
Authors: Soserov Lyubomir , Boyadzhieva Tanya , Koleva Violeta , Stoyanova Antonia , Stoyanova Radostina
Published: December 2016

This study provides new data on the fabrication of hybrid battery-supercapacitor with an excellent cycling stability based on composites of α-Ni(OH)2 and activated carbon (AC). The α-phase, Ni(OH)2.0.3H2O, consists of charged Ni(OH)2-x layers, SO2-
4 anions being intercalated in the interlayer spaces. The hydroxide has a mesoporous structure and contains nanometric primary particles bounded into micrometric aggregates. The supercapacitor performance of α-Ni(OH)2 mixed with AC is tested by galvanostatic experiments in KOH-LiOH electrolyte. The ratio between α-Ni(OH)2 and AC is varied in a whole concentration range: 0≤x≤100 wt.%. In comparison with the symmetrical supercapacitor, the composite electrodes containing α-Ni(OH)2 between 6 and 35 wt. % demonstrate higher and more stable discharge capacitance, as well as a higher effectiveness of charge-discharge process. α-Ni(OH)2 has a better cycling stability in comparison with the β-phase. The supercapacitor performance is discussed in terms of structure and morphology stability of α-Ni(OH)2 in alkaline electrolyte.
Effect of Plasma Nitriding on Mechanical and Tribological Properties of 42CrMo4 Steel
Authors: Doan Thanh Van , Dobrocký David , Pokorny Zdenek , Kusmic David , Nguyen Van Thuan
Published: December 2016

The 42CrMo4 steel is a material popularly used in weapon manufacture. This article that deals with improving wear resistance of gun components will study tribological behaviour of above steel, treated by plasma nitriding technologies under different condition of duration and gas ratio. The friction coefficient and wear rate were investigated using the wear test based on principle “ball on disc”. The results were supplemented with mechanical properties and metallographic documentations. The results show that plasma nitriding improved dramatically the mechanical properties and wear resistance of materials, and the level of wear resistance was related to the nitriding process parameters.
The Use of Nanotechnologies in Vehicle Engines Storing
Authors: Binar Tomas , Sedlarikova Marie , Hyánek Vladimír
Published: December 2016

The existing system of protection of a machine group, engines inTATRA 815 vehicles, from corrosion effects is only applicable tovehicles parked indoors; in sea, air, railway and road transportation,individual machine components constituting functional parts of theengine cannot be protected adequately from relative air humiditypossibly inducing degradation processes in a material leading to theoccurrence of corrosion. In the paper, a scientific method of multicriteriaevaluation of variants is employed, using Saaty’s method to determinecriteria weights and Metfessel’s method of allocation of 100 points, tomake a comparison of the existing method of storage of T3-930-50 typeengine and a newly designed system of engine storage that is applicableindoors as well as outdoors, or possibly during transportation.
Comparison of Results Obtained Using Different Turbulence Models in Analysis Differentially Pumped Chamber
Authors: Maxa Jiří , Bílek Michal , Hlavatá Pavla
Published: December 2016

The improvement in imaging parameter of environmental electron microscope can be applied to diagnosing the development of batteries, where it is (ESEM) used for photographing before and after cycling in samples of electron masses (1).
Analysis of the Gas Flow in the Specimen Chamber of the Environmental Scanning Electron Microscope
Authors: Bílek Michal , Vyroubal Petr , Hlavatá Pavla
Published: December 2016

Diagnostic methods can be also used in the development of new batteries to serve as a diagnostic method which allows to observe changes in electron masses before and after cycling.
Automation Capabilities of Solar Modules Defect Detection by Thermography
Authors: Vaněk Jiri , Repko Ilja , Klima Jakub
Published: December 2016

This paper deals with the automation capabilities of defective solar modules detection by thermographic camera mounted on a dron or on the car roof. During thermography imaging analysis of large photovoltaic power plants there are captured large numbers of images. These images are then analyzed by human operators. Given the vast amount of images, which are sometimes very similar, and given of the specificity of some defects, the work of operators can be replaced by the automation recognizing of anomalies software. Two methods for the automatic detection of defects in thermal imaging pictures were developed and validated. First one method is based on the geometric information of tested modules and on the assumption that defective cell has an increased temperature along its whole surface and therefore will appear as a regular geometric shape which is recognizable by geometric comparisons. The second method does recognition by usage of trained artificial neural network.
Manufacturing of Perovskite Solar Cell Based on CH3NH3PbI3-2Cl2 Structure
Authors: Strachala David , Kadlec Michal , Sionová Marcela , Hylský Josef , Weiter Martin , Čudek Pavel , Vaněk Jiri
Published: December 2016

The aim of the work is development of the perovskite solar cell with an CH3NH3PbI3-2Cl2 active layer. As a part of the work were created an eight perovskite solar cells. Six of the samples were active and two inactive because of high temperature during the manufacturing process. The best of the sample reached η
MAX = 7.22 % conversion efficiency. Based on the analysis of the samples was modified manufacturing process to avoid damage of layers. The temperature of preheating during application of CH3NH3PbI3-2Cl2
was reduced from 140 °C to 60 °C. Degradation of the perovskite material has appeared after 20 hours. The samples have lost 20 % of its output power. Manufacturing process will be modified in order to increase the conversion efficiency and stability of perovskite solar cells.
Sodium-Titanate as Negative Electrode Material for Sodium-Ion Batteries
Authors: Libich Jiri , Kundu Manab , Cech Ondrej , Sedlaříková Marie , Vondrák Jiří , Čudek Pavel , Maca Josef
Published: December 2016

This paper describes our initial work focused on sodium-titanate electrode material. The sodium-titanate material analogy to lithium-titanate or lithium metatitanate (Li2TiO3) can be used in rechargeable aprotic battery systems. A sodium-ion system seems to be promising substituent for lithium-ion systems, at present the energy storage application as stationary energy storage systems (in range of MWh) through batteries for propulsion of electric vehicles become more important than ever. The main advantage of sodium-ion system is the price and sodium abundance in earth’s crust. A challenge for the sodium systems is identification of a suitable negative electrode material (anode) because sodium atom is too big for intercalation into graphite. Our experiments deal with synthetization process of NaxTiyOz in SOL form, followed by its transformation to fibres form.
Mixed Sodium Titanate As an Anode for a Sodium-Ion Battery
Authors: Cech Ondrej , Vanýsek Petr , Chladil Ladislav , Castkova Klara
Published: December 2016

Sodium-ion batteries are very promising complementary power sources usable in applications where cost of starting materials and battery itself is more important than its energy density. Mixed sodium titanate anode material with two electroactive crystallographic phases was successfully synthesized via microwave assisted hydrothermal synthesis. The electrochemical performance of Na2Ti3O7/Na2Ti6O13 mixed material is reported together with its structural characterization. SEM images revealed that the final product has nanorods-like structure. The widths of the particles are in the range of hundreds of nanometers and are strongly dependent on calcination temperature unlike the particle lengths remain almost unchanged with the temperature and are in the range of several microns. The initial discharge capacity of the material is 90 mAh/g.
Computational modeling of epithelial fluid and ion transport in the parotid duct after transfection of human aquaporin-1
Authors: Fong Shelley , Chiorini John A , Sneyd James , Suresh Vinod
Published: December 2016

Previous studies have shown that localized delivery of the aquaporin-1 (AQP1) gene to the parotid duct can restore saliva flow in minipigs following irradiation-induced salivary hypofunction. The resulting flow rate and electrochemistry of secreted saliva contradicts current understanding of ductal fluid transport. We hypothesized that changes in expression of ion transport proteins have occurred following AQP1 transfection. We use a mathematical model of ion and fluid transport across the parotid duct epithelial cells to predict the expression profile of ion transporters that are consistent with the experimental measurements of saliva composition and secretion rates. Using a baseline set of parameters, the model reproduces the data for the irradiated, non-AQP1-transfected case. We propose three scenarios which may have occurred after transfection, which differ in the location of the AQP1 gene. The first scenario places AQP1 within nonsecretory cells, and requires that epithelial sodium channel (ENaC) expression is greatly reduced (1.3% of baseline), and ductal bicarbonate concentration is increased from 40.6 to 137.0 mM, to drive water secretion into the duct. The second scenario introduces the AQP1 gene into all ductal cells. The final scenario has AQP1 primarily in the proximal duct cells which secrete water under baseline conditions. We find the change in the remaining cells includes a 95.8% reduction in ENaC expression, enabling us to reproduce all experimental ionic concentrations within 9 mM. These findings provide a mechanistic basis for the observations and will guide the further development of gene transfer therapy for salivary hypofunction.

NEW & NOTEWORTHY Following transfection of aquaporin into the parotid ducts of minipigs with salivary hypofunction, the resulting increase in salivary flow rates contradicts current understanding of ductal fluid transport. We show that the change in saliva electrochemistry and flow rate can be explained by changes in expression of ion transporters in the ductal cell membranes, using a mathematical model replicating a single parotid duct.
Expression and Processing of Amyloid Precursor Protein in Vascular Endothelium
Authors: d'Uscio Livius V. , He Tongrong , Katusic Zvonimir S.
Published: December 2016

Amyloid precursor protein (APP) is evolutionary conserved protein expressed in endothelial cells of cerebral and peripheral arteries. In this review, we discuss mechanisms responsible for expression and proteolytic cleavage of APP in endothelial cells. We focus on physiological and pathological implications of APP expression in vascular endothelium.
Cluster-Randomized Controlled Study of SMS Text Messages for Prevention of Mother-to-Child Transmission of HIV in Rural Kenya
Authors: Kassaye Seble G. , Ong’ech John , Sirengo Martin , Kose Judith , Matu Lucy , McOdida Peter , Simiyu Rogers , Syengo Titus , Muthama David , Machekano Rhoderick
Published: December 2016

Background. Antiretroviral medications are key for prevention of mother-to-child transmission (PMTCT) of HIV, and transmission mitigation is affected by service delivery, adherence, and retention. Methods. We conducted a cluster-randomized controlled study in 26 facilities in Nyanza, Kenya, to determine the efficacy of SMS text messages on PMTCT outcomes. The relative risk and confidence intervals were estimated at the facility level using STATA. Results. 550 women were enrolled, from June 2012 to July 2013. The median age was 25.6 years, and 85.3% received ARVs. Maternal ARV use was similar between the intervention and control arms: 254/261 (97.3%) versus 241/242 (99.6%) at 34–36 weeks of gestation and 234/247 (94.7%) versus 229/229 (100%) at delivery. Among infants, 199/246 (80.9%) and 209/232 (90.1%) received ARVs (RR: 0.91; 95% CI: 0.77–1.14); 88% versus 88.6% were tested for HIV at 6 weeks, with 1/243 (0.4%) and 3/217 (1.4%) positive results in the intervention and control arms, respectively. Communication increased in both the intervention and control arms, with the mean number of 7.5 (SD: 5.70) compared with 6 (SD: 9.96), p<0.0001. Conclusions. We identified high ARV uptake and infant HIV testing, with very low HIV transmission. Increased communication may influence health-seeking behaviors irrespective of technology. The long-term effectiveness of facilitated communication on PMTCT outcomes needs to be tested. The study has been registered on ClinicalTrials.gov under the identifier NCT01645865.
Anterior Chamber Angle Evaluation following Phakic Posterior Chamber Collamer Lens with CentraFLOW and Its Correlation with ICL Vault and Intraocular Pressure
Authors: Eissa Sherif A. , Sadek Sherin H. , El-Deeb Mohamed W. A.
Published: December 2016

Purpose.To assess intraocular pressure (IOP), lens vaulting, and anterior chamber (AC) angle width, following V4C implantable Collamer lens (ICL) procedure for myopic refractive error.Methods.A prospective case series that enrolled 54 eyes of 27 patients that were evaluated before and after V4C phakic posterior chamber Collamer lens implantation for correction of myopic refractive error. Preoperative measurement of IOP was done using Goldmann applanation tonometer and anterior chamber angle width using both Van Herick slit lamp grading system and Scheimpflug tomography imaging (Oculus Pentacam). Follow-up of the aforementioned variables was at 1, 6, and 18 months postoperatively, together with ICL vault measurements.Results.The mean baseline IOP of11.69±2.15showed a statistically significant (P=0.002) increase after 1 month that remained unchanged at 6 and 18 months postoperatively, with mean value of16.07±4.12,16.07±4.10, and16.07±4.13, respectively. Pentacam AC angle width showed a statistically significant decrease at 1(P=0.025), 6(P=0.016), and 18(P=0.010)months postoperatively, with mean preoperative value of40.14±5.49that decreased to25.28±5.33,25.46±5.44, and25.49±5.38, at 1, 6, and 18 months, respectively. Mean ICL vault showed moderate correlation with Pentacam AC angle width at 1(r=-0.435)and 6(r=-0.424)months.Conclusion. V4C ICL implantation resulted in decrease in AC angle width and increase in IOP, within acceptable physiological values at all time points.
Determinants of Under-Five Mortality in High Mortality Regions of Ethiopia: An Analysis of the 2011 Ethiopia Demographic and Health Survey Data
Authors: Gebretsadik Solomon , Gabreyohannes Emmanuel
Published: December 2016

The study was a secondary analysis of existing data from the 2011 Ethiopia Demographic and Health Survey data. Of the 2097 live births recorded in Affar, Somali, Benishangul-Gumuz, and Gambela regions of Ethiopia between 2006 and 2011, 366 deaths before the age of five years were reported. The univariable and multivariable Cox proportional regression models were fitted to select the factors affecting under-five mortality in these regions. The model revealed that under-five mortality significantly associated with preceding birth interval, family size, birth type, breastfeeding status, source of drinking water, and income of mother. Children born after a preceding birth interval of 2-3 years and 3 years and above were significantly less likely to have died before their fifth birthday than those born within two years. Children who were breastfed, for any period, were 25.5% (HR 1.255, 1.005–1.567, p = 0.045) less likely to have died before their fifth birthday than those who were not breastfed. Increased birth interval time corresponds to a low probability of child mortality. Thus, mothers should be encouraged to wait for a sufficient number of months after a birth to conceive another child. Furthermore, breastfeeding was of paramount importance in the fight against child mortality.
Gliosarcoma with Primary Skull Base Invasion
Authors: Nguyen Quoc-Bao D. , Perry Avital , Graffeo Christopher S. , Nesvick Cody L. , Raghunathan Aditya , Jentoft Mark E. , O’Neill Brian P. , Morris Padraig P. , Morris Jonathan M. , Van Gompel Jamie J.
Published: December 2016

Gliosarcoma is an uncommon variant of glioblastoma, which commonly demonstrates dural attachment. However, skull base invasion is rarely seen with this entity. Herein, we report a 44-year-old female patient diagnosed with primary intracranial gliosarcoma extensively invading the skull base and muscles of mastication. She presented to our institution with a three-month history of difficult right jaw opening and retro-orbital pressure and one week of severe right-sided postauricular headache. Head CT demonstrated a 6 cm mass with marked bony erosion. Brain MRI at a one-week interval more clearly characterized tumor extension through the right orbit and muscles of mastication, with overall growth to 7 cm and worsening midline shift. The patient underwent a right frontotemporal craniotomy for gross total resection. Pathology confirmed the diagnosis of gliosarcoma, IDH-wildtype (WHO grade IV). Her postoperative course was uneventful and she was discharged at preoperative neurologic baseline. To our knowledge, this is the third reported case of a primary intracranial gliosarcoma with direct invasion of skull base, brain parenchyma, and extracranial compartment. However, this is the first report case of primary GS invading the surrounding musculature and orbit. This case report highlights the rapid aggressiveness of gliosarcomas and further a prior undescribed radiographic and anatomic finding of skull base invasion with this entity.
Informing Active Play and Screen Time Behaviour Change Interventions for Low Socioeconomic Position Mothers of Young Children: What Do Mothers Want?
Authors: Downing Katherine L. , Best Keren , Campbell Karen J. , Hesketh Kylie D.
Published: December 2016

Introduction. This study investigated views of mothers from disadvantaged urban and regional areas (i.e., beyond major capital cities) as potential end users of child active play and screen time behaviour change interventions, with a focus on text messaging and web-based delivery platforms. Methods. Thirty-two mothers (22 urban; 10 regional) were interviewed. Purpose-designed questions covered topics regarding mothers’ preferences for accessing and receiving information related to parenting and child active play and screen time. Data from transcribed interviews were analysed to identify responses and key themes. Results. Mothers reported frequently accessing parenting- and child-related information online. Regional mothers reported seeking information by talking with other people less frequently than urban mothers and seemed to have a stronger preference for receiving information online. There were few differences between responses from low and high educated mothers. The majority of mothers reported that they would be happy to receive text messages containing information about active play and screen time and that they would find a dedicated website with this information useful. Conclusions. Mothers in this study held favourable views on the potential of receiving information via new communication technologies. Future interventions targeting socioeconomically disadvantaged mothers may benefit from delivering intervention messages via these technologies.
Role of Recombinant DNA Technology to Improve Life
Authors: Khan Suliman , Ullah Muhammad Wajid , Siddique Rabeea , Nabi Ghulam , Manan Sehrish , Yousaf Muhammad , Hou Hongwei
Published: December 2016

In the past century, the recombinant DNA technology was just an imagination that desirable characteristics can be improved in the living bodies by controlling the expressions of target genes. However, in recent era, this field has demonstrated unique impacts in bringing advancement in human life. By virtue of this technology, crucial proteins required for health problems and dietary purposes can be produced safely, affordably, and sufficiently. This technology has multidisciplinary applications and potential to deal with important aspects of life, for instance, improving health, enhancing food resources, and resistance to divergent adverse environmental effects. Particularly in agriculture, the genetically modified plants have augmented resistance to harmful agents, enhanced product yield, and shown increased adaptability for better survival. Moreover, recombinant pharmaceuticals are now being used confidently and rapidly attaining commercial approvals. Techniques of recombinant DNA technology, gene therapy, and genetic modifications are also widely used for the purpose of bioremediation and treating serious diseases. Due to tremendous advancement and broad range of application in the field of recombinant DNA technology, this review article mainly focuses on its importance and the possible applications in daily life.
Correction of TRMM 3B42V7 Based on Linear Regression Models over China
Authors: Liu Shaohua , Yan Denghua , Qin Tianling , Weng Baisha , Li Meng
Published: December 2016

High temporal-spatial precipitation is necessary for hydrological simulation and water resource management, and remotely sensed precipitation products (RSPPs) play a key role in supporting high temporal-spatial precipitation, especially in sparse gauge regions. TRMM 3B42V7 data (TRMM precipitation) is an essential RSPP outperforming other RSPPs. Yet the utilization of TRMM precipitation is still limited by the inaccuracy and low spatial resolution at regional scale. In this paper, linear regression models (LRMs) have been constructed to correct and downscale the TRMM precipitation based on the gauge precipitation at 2257 stations over China from 1998 to 2013. Then, the corrected TRMM precipitation was validated by gauge precipitation at 839 out of 2257 stations in 2014 at station and grid scales. The results show that both monthly and annual LRMs have obviously improved the accuracy of corrected TRMM precipitation with acceptable error, and monthly LRM performs slightly better than annual LRM in Mideastern China. Although the performance of corrected TRMM precipitation from the LRMs has been increased in Northwest China and Tibetan plateau, the error of corrected TRMM precipitation is still significant due to the large deviation between TRMM precipitation and low-density gauge precipitation.
Severe Erosive Pill Esophagitis Induced by Crizotinib Therapy: A Case Report and Literature Review
Authors: Jung Patrick , Fortinsky Kyle J. , Gallinger Zane R. , Tartaro Piero
Published: December 2016

Previous case reports have described esophagitis thought to be secondary to crizotinib, an oral tyrosine-kinase inhibitor used in the treatment of anaplastic lymphoma kinase- (ALK-) positive non-small cell lung cancer (NSCLC). In those reports, the interval development of esophagitis was between two days and three months after initiating or reinitiating crizotinib therapy. We present a woman who developed ulcerative esophagitis ten months after beginning crizotinib therapy, which is highly unusual. We believe the provoking factor was a change in her medication administration routine, done to accommodate religious practices during the period of Ramadan. This case illustrates the mechanism of pill esophagitis and reinforces the importance of patient education when it comes to medication administration. Clinicians may consider early imaging or investigations in patients with concerning symptomatology in the context of crizotinib therapy or other offending medications. Future research may help to uncover additional risk factors for this exceedingly rare diagnosis in this patient population. Most importantly, this case highlights nonpharmacologic ways to improve tolerability and decrease adverse effects of a highly effective chemotherapeutic agent.
PS1/γ‐Secretase‐Mediated Cadherin Cleavage Induces β‐Catenin Nuclear Translocation and Osteogenic Differentiation of Human Bone Marrow Stromal Cells
Authors: Bonfim Danielle C. , Dias Rhayra B. , Fortuna-Costa Anneliese , Chicaybam Leonardo , Lopes Daiana V. , Dutra Hélio S. , Borojevic Radovan , Bonamino Martin , Mermelstein Claudia , Rossi Maria Isabel D.
Published: December 2016

Bone marrow stromal cells (BMSCs) are considered a promising tool for bone bioengineering. However, the mechanisms controlling osteoblastic commitment are still unclear. Osteogenic differentiation of BMSCs requires the activation of β‐catenin signaling, classically known to be regulated by the canonical Wnt pathway. However, BMSCs treatment with canonical Wnts in vitro does not always result in osteogenic differentiation and evidence indicates that a more complex signaling pathway, involving cadherins, would be required to induce β‐catenin signaling in these cells. Here we showed that Wnt3a alone did not induce TCF activation in BMSCs, maintaining the cells at a proliferative state. On the other hand, we verified that, upon BMSCs osteoinduction with dexamethasone, cadherins were cleaved by the PS1/γ‐secretase complex at the plasma membrane, and this event was associated with an enhanced β‐catenin translocation to the nucleus and signaling. When PS1/γ‐secretase activity was inhibited, the osteogenic process was impaired. Altogether, we provide evidence that PS1/γ‐secretase‐mediated cadherin cleavage has as an important role in controlling β‐catenin signaling during the onset of BMSCs osteogenic differentiation, as part of a complex signaling pathway responsible for cell fate decision. A comprehensive map of these pathways might contribute to the development of strategies to improve bone repair.