bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Structural Inhomogeneities in GaAs/AIGaAs Superlattices
Authors: Huang P. C. , Stock S. R. , Torabi A. , Summers C. J.
Published: March 2019

Thin films containing periodic chemical or strain modulation (e.g. artificial superlattices or SL) are often characterized nondestructively by X-ray double-axis diffractometry. The satellite peaks from the modulated structure allow analysis of layer structure, elemental concentration and strain profile. This paper focuses on the effect of layer uniformity on the rocking curves of (001) GaAs/AlxGa1-xAsSL. Double-axis diffractometry for results from MBE samples with 800 Å SL periods and x=0.35 are compared for GaAs/AlGaAs layer thicknesses of 350/450, 400/400 and 450/350 Å. Symmetric (004) and asymmetric (315) diffraction planes are used to measure parallel and perpendicular misfit strains, layer periodicity and aluminum concentration. A modified kinematical scattering model, correcting for absorption and extinction, is used to calculate the satellite peak intensities and spacings. The relative thicknesses of GaAs and AlGaAs and the aluminum elemental concentration are optimized by matching with experimental results. The effect of nonuniform layer thickness on SL peak intensities is also investigated. The experimental results, the modified kinematical scattering calculations and dynamical theory agree closely for the 3-4 /zm thickness layers studied.
X-ray Diffraction of Plasma Nitrided Ti-6AI-4V
Authors: Raveh A. , Kimmel G. , Avni R. , Grill A.
Published: March 2019

Ti-6Al-4V alloy has been nitrided in plasmas of N2 -H2 -Ar. The structure has been characterized by X-ray diffraction (XRD) for the determination of the products formed. The information was supported by elemental analysis with Auger Electron Spectroscopy (AES).

Three phases were identified as follows: δ-TiN, ε-Ti2N and α'-Ti (solid solution of nitrogen in titanium). The gas-feed composition affects the nitriding process as found from phase orientation and relative concentration of the products.
Stress Analysis of Thin-Film SmS Using a Seemann- Bohlin Diffractometer
Authors: Moore Fergus E.
Published: March 2019

X-ray diffraction is especially useful in analyzing the phase-transition response of thin-film SmS to strain impressed by the two-dimensional constraints of the substrate. A biaxial-stress model is applied and extended to a randomly-oriented crystalline film. The changes in macrostress, the compliance tensor and effective Poisson's ratio are evaluated near the hulk phase transition. An analysis of crystallite size and microstrain broadening is also presented including broadening effects due to biaxial macrostrain on the randomly-oriented crystallites. These results illustrate the effect of a constraining, biaxial-stress field on the unusual elastic character of samarium monosulfide. It is demonstrated that the thin-film geometry suppresses the first-order phase transition allowing only linear changes between the semiconducting and metallic states.
Fundamental Parameter-Based X-ray Fluorescence Analysis of Thin and Multilayer Samples
Authors: de Boer D. K. G. , Brouwer P. N.
Published: March 2019

The Fundamental Parameter-based calculation of x-ray fluorescence intensities for thin and multilayer samples is performed with new formulas. By the calculations it is shown that both intra- and inter-layer secondary fluorescence can cause significant enhancement. With a method based on the discussed theory, it is possible to determine the composition and layer thicknesses of multilayer samples. Analyses are discussed of samples from IC technology and magnetic recording. Furthermore, the angular dependence of intensities is calculated, in good agreement with experiments performed with a novel spectrometer.
XRF Macroprobe Analysis of Geologic Materials
Authors: Gilfrich N. L. , Leyden D. E. , Erslev E. A.
Published: March 2019

An x-ray fluorescence macroprobe was built for intermediate-scale compositional mapping to bridge the gap in spatial resolution between bulk x-ray fluorescence and electron beam methods. The macroprobe was optimized for quantitative whole rock mapping on a millimeter scale to evaluate changes in bulk composition of fine-grained mineral aggregates.
X-ray Fluorescence Analysis of Trace Metals in the Annual Growth Layers of Freshwater Mussel Shells
Authors: Maddox William E. , Duobinis-Gray Leon , Owen David A. , Sickel James B.
Published: March 2019

Freshwater mussels (Mollusca: Unionidae) are filter feeders that are relatively immobile, widely distributed and are known to concentrate trace metals in their shells (1,2,3). These characteristics make them good candidates for monitoring metal pollution in lakes and rivers. Another characteristic of mussels that make them particularly attractive as pollution monitors is the fact the shell is deposited in distinctive, annual growth layers. The concentrations of metals in these shell layers may provide a history ol the metals present in the environment where the mussel was collected.
Resolution Enhancement for Cu Kα Emission of Y-Ba-Cu-O Compounds
Authors: Saitoh N. , Higashi Y. , Minarai M. , Fukushima S. , Gohshi Y. , Kohiki S. , Wada T.
Published: March 2019

Since the discovery of the Y-Ba-Cu-O superconductors, their physical properties have been investigated by various methods. The chemical state of Cu in Y-Ba-Cu-O compounds la one of the greatest issues because the mechanism of superconductivity in Y-Ba-Cu-O is not understood theoretically. We are analyzing X-ray fluorescence spectra of Cu compounds including superconductors, intending to analyze the chemical state of Cu in Y-Ba-Cu-O. As for other 3d transition elements, structures due to unpaired electrons appear clearly on the lower energy side of the Kα1 line of the element. However there are little differences observed among Cu Kα spectra of Cu compounds even if they are measured by a high-resolution two-crystal spectrometer (see Fig. 1). Although Cu is a member of 3d transition elements, its Kα spectrum shows somewhat different behavior compared with other 3d transition elements. This point is one subject we are interested in.
Stress Measurements with a Two-Dimensional Real-Time System
Authors: Borgonovi G.M. , Gazza C.P.
Published: March 2019

Conventional methods of determination of residual stress in polycrystalline samples use either diffractometers or one-dimensional position-sensitive detectors. The most commonly used technique, the so-called "sin2ψ" method, requires several measurements at different angular positions of the sample. With diffractometers, two rotations are required, while with one-dimensional detectors, one rotation is required (except for the so-called single exposure technique, which requires two one-dimensional position-sensitive detectors). Rotation can be a potential source of errors if the sample is not aligned very carefully.
Application of a New Solid State X-Ray Camera to Stress Measurement
Authors: Korhonen M.A. , Lindroos V.K. , Suominen L.S.
Published: March 2019

X-ray camera methods of stress measurement are inherently flexible and easy to apply in different situations because of the low weight, portability and maneuverability of the equipment. However, the digital intensity recording with the resulting objectivity and better statistical accuracy has given the diffractometer methods a distinct advantage over the conventional camera methods.
The Crystal Structures of the Cubic and Tetragonal Phases of Y1Ba3Cu2O6.5 + δand Y1Ba4Cu2O7.5 + δ
Authors: Rodriguez M. A. , Simmins J. J. , McCluskey P. H. , Zhou R. S. , Snyder R. L.
Published: March 2019

The discovery of the superconducting material Y1Ba2Cu3O6+δ( “123” material) resulted in a world wide interest in the pseudo-ternary system BaO·YO·CuO. A complete study of the phases present in this system was initiated to develop a better understanding and processing of the superconducting 123 material. The crystal structures were established for two of the three ternary compounds in this system immediately after the discovery of superconductivity. One such phase was a green insulating compound Y2Ba1Cu1O5(”211”) which has the space group. The superconducting 123 compound was found to have the space group Pmmm and an ordered triple-celled perovskite structure.
On the Selection of the Value for the Experimental Wavelength in Powder Diffraction Measurements
Authors: Jenkins Ron
Published: March 2019

With the increasing use of automated powder diffractometers, more and more reliance is being placed on peak searching and α2 stripping software to allocate a wavelength for the calculation of the d-value from the observed peak maxima. The complications in the correct allocation of the wavelength are well known and include problems due to the polychromatic nature of the diffracted X-ray beam, changes in the angular dispersion of the diffractometer over the angular range of the experimental data, and effects of instrument geometric aberrations on the profile shape. Further difficulties may accrue because of idiosyncrasy of the peak searching arid α2 stripping software.
Use of the Dow-Developed DSC/XRD/MS in the Study of Several Model Copper-Based Catalyst Systems
Authors: Newman R. A. , Blazy J. A. , Fawcett T. G. , Whiting L. F. , Stowe R. A.
Published: March 2019

Due to the difficulty of analyzing materials at high temperatures and in reactive atmospheres, solid-state catalysts have often been developed with little knowledge of the true chemical behavior of the catalyst, except on a bulk scale. In the field of solid-state catalysis research, a great deal of time and effort is presently being spent to better characterize the chemical and physical properties which determine a particular catalyst‘s efficiency, lifetime, and selectivity. Recently, we have undertaken a study of model copper catalysts at The Dow Chemical Company in an effort to better understand the chemical and physical properties which determine the efficiency, regenerability, and lifetime of this type of solid state catalyst.
Simultaneous Determination of the Thickness and Composition of Thin Film Samples Using Fundamental Parameters
Authors: Willis James E.
Published: March 2019

The use of empirical analysis techniques for the simultaneous determination of the thickness and composition of thin film samples usually requires a suite of well characterized similar type standards. While this may be adequate for a quality control application, this requirement severely limits the utility of X-ray fluorescence in the analysis of thin films in a service lab or research environment.

The use of fundamental parameters in the analysis of thin films allows the simultaneous determination of the thickness and composition of single and multiple layer thin film unknown samples without the use of similar type standards.
A 4 Crystal Monochromator for High Resolution Rocking Curves
Authors: Green Robert W.
Published: March 2019

X-ray characterization of single crystal materials in the form of thin layers can be accomplished with the use of a double crystal diffractometer. The resultant rocking curve is a convolution of the Bragg reflection from both the first and second crystals. The width of the rocking curve at half-height is a measure of the crystal perfection of a materiel. Since the FWHM for the material being analyzed cannot be less than that of the first crystal (Monochromator), the first crystal should be of very good crystal quality. The problem that arises with the two crystal parallel configuration (Fig. 1) is that the monochromator crystal must be changed each time a material of different orientation or stoichiometry with different resultant lattice constants is analyzed. This requires changing the monochromator and re-aligning the double crystal diffractometer.
Evolution of X-Ray Instrumentation & Techniques, 1970-1990
Authors: Jenkins Ron
Published: March 2019

While both X-ray Fluorescence Analysis and X-ray Powder Diffractometry have their roots back in the earlier half of this century it wasn't until the 1960s that the two techniques became widely accepted. The growth in the application of X-ray methods for materials analysis grew rapidly between 1960 and 1970, then gained another major leap forward in the early ‘70s with the introduction of mincomputers. The introduction of Si(Li) detectors in the late’ 60s and early ‘70s added a further dimension to the available instrumentation. This paper reviews the growth in the field of X-ray materials analysis and highlights the major mile-stones in intrumentation and techniques.
Improvement of the Detection Sensitivity of Edxrf Trace Element Analysis by Means of Efficient X-Ray Focusing Based on Strongly Curved Hopg Crystals
Authors: Beckhoff Burkhard , Kanngießer Birgit
Published: March 2019

X-ray focusing based on Bragg reflection at curved crystals allows collection of a large solid angle of incident radiation, monochromatization of this radiation, and condensation of the beam reflected at the crystal into a small spatial cross-section in a pre-selected focal plane. Thus, for the Bragg reflected radiation, one can achieve higher intensities than for the radiation passing directly to the same small area in the focal plane. In that case one can profit considerably from X-ray focusing in an EDXRF arrangement. The 00 2 reflection at Highly Oriented Pyrolytic Graphite (HOPG) crystals offers a very high intensity of the Bragg reflected beam for a wide range of photon energies. Furthermore, curvature radii smaller than 10 mm can be achieved for HOPG crystals ensuring efficient X-ray focusing in EDXRF applications. For the trace analysis of very small amounts of specimen material deposited on small areas of thin-filter backings, HOPG based X-ray focusing may be used to achieve a very high intensity of monochromatic excitation radiation.
Comparison of Various Descriptions of X-Ray Tube Spectra
Authors: Schoßmann B. , Wiederschwinger H. , Ebel H. , Wernisch J.
Published: March 2019

We have developed an algorithm for calculating the x-ray tube continuum based on the eqidistribution proposed by Love and Scott, extended the description of white and characteristic radiation given by Wiederschwinger et al for the energy range 10 to 50 keV to the low energy range from 5 to 30 keV, and compared the results from this algorithm to those responses obtained from algorithms using the absorption correction of Pochou and Pichoir, Philibert, Sewell and Pella. The comparison to other models showed a significandy better performance by our model.
Assessing the Validity of Diffraction Stress Data with the Goodness-Of-Fit Statistic
Authors: Lohkamp Thomas A. , Winhoitz R. A.
Published: March 2019

According to the standard model, strain in polycrystalline materials transforms like a tensor when measured with diffraction in different directions. This model predicts linear variation of d-spacing with sin2ѱ if the stresses σ13 and σ23 are absent or predicts ѱ-splitting if they are present. In diffraction stress measurements, d vs. sin2ѱ plots often exhibit behavior that cannot be predicted from this model. When such discrepancies are observed, stresses calculated from the data will not always be valid. Current practice is to determine the validity of data by visually inspecting d vs. sin2ѱ plots and subjectively assessing the goodness-of-fit. This paper proposes the χ2 statistic as a tool for quantitatively determining goodness-of-fit, and it presents experimental results from the application of the statistic.
Internal Stress in an Alumina/Silicon Carbide Whisker Composite
Authors: Oden M. , Ericsson T. , Cohen J. B.
Published: March 2019

The internal stress state in a Al2O3-SiC composite has been studied with X-ray diffraction and with calculations with a modified Eshelby model. The influence (on the internal stress state) of volume fraction, temperature, geometric shape, and the orientation of the silicon carbide particles are discussed. The stress tensors were measured in both the matrix and in the reinforcing phase, and the macro- and microstresses were separated for ail the components. Good agreement with the microstresses for the Eshelby model is found in all cases.

Results from X-ray diffraction experiments at low temperature (45-295 K) on the coefficient of thermal expansion are also presented.
Characterization Of Single Crystal Epitaxial Aluminum Nitride Thin Films On Sapphire, Silicon Carbide And Silicon Substrates By X-Ray Double Crystal Diffractometry And Transmission Electron Microscopy
Authors: Chaudhuri J. , Thokala R. , Edgar J. H. , Sywe B. S.
Published: March 2019

Epitaxial AIN thin films grown on sapphire, silicon and silicon carbide substrates were studied using x-ray double crystal diffractometry and transmission electron microscopy to compare the structure, residual stress and defect concentration in these thin films. The AIN thin films was found to have a wurtzite type of structure with a small distortion in lattice parameters which results in a small residual stress of the order of 109 dynes/cm2 in the film. The strain due to lattice parameter mismatch between the substrate and film is too small to account for the residual stress present. The calculated stress from the difference in thermal expansion coefficients between the film and substrate agrees well with the experimental values. Both the x-ray and transmission electron microscopy measurements indicate a low defect density in the AIN thin film grown on 6H-SiC substrate which could be attributed to the small difference in lattice parameters between AIN and 6H-SiC. The defect density in the AIN thin film grown on other substrates were considerably higher. This is the first report of the successful growth of single crystal AIN thin films with such a low concentration of defect density.
Determination of Thickness and Composition of Thin AlxGa1-xAs Films on GaAs substrates by Total Electron Yield (Tey) Measurements
Authors: Ebel Horst , Svagera Robert , Ebel Maria F. , Zagler Norbert
Published: March 2019

In our paper “Determination of thickness and composition of thin AlxGa1-xAs layers on GaAs by total electron yield (TEY)” we described the principles of the determination of thickness t and Al concentration x employing TEY. The essential experimental quantities are the absorption edge jumps of the-eleraents measured in TEY-mode:

Since the problem asks for the quantification of two unknowns (x,t), at least two TEYjumps are needed. The K jumps of Al and Ga deliver reliable information. From the theoretical approach1,2 of quantitative TEY a nearly linear relationship between the measured TEY jumps and the composition (in wt%) has to be expected. The As concentration varies over the interesting composition range 0<x<0.6 from approximately 50 to 60wt% and causes a similar variation of the TEY jump versus x. In combination with the statistical significance of the experimental data we neglect the TEY K jump information from As.
Light Element Analysis Using Txrf
Authors: Fukuda T. , Shoji T. , Funabashi M. , Utaka T. , Arai T. , Miyazaki K. , Shimazaki A. , Wilson R.
Published: March 2019

Over the past few years there has been substantial progress in the TXRF analysis of heavy element surface contamination on silicon wafers. Further advances and improvements are desired in the analytical performance and hardware. Extension of the analytical range to include the light elements is particularly desirable.

In the case of light element analysis, sodium and aluminum impurities have been monitored in the IC production process. The increase of the sodium impurity in a silicon wafer gives rise to a decrease in the insulation in IC devices and the growth of the SiO2 film is disturbed by the prsence of aluminum impurity on the silicon wafer surface.
Quantitative Xrfa of Carbon in a Special Matrix by the Fundamental Parameter Method
Authors: Weber Franz A. , Silva Luiz. B. Da , Barbee Troy W. , Ciarlo Dino , Mantler Michael
Published: March 2019

We report on results obtained from experiments using specially prepared carbon substrates and treatment of the data by means of recently introduced theory. Medium Z grids with known parameters have been coated on top of pyrolytic carbon substrates to achieve well defined absorption geometries. The various copper grids exhibit satisfactory performance in terms of mechanical stability, homogeneity and uniformity of the coating. A detailed study of the measurement results shows that there is a more rapid increase of the associated C-Kα countrate from the coated samples compared to the pure elements and is attributed to the contribution of secondary enhancement effects, including those resulting from photoelectrons generated after the primary ionization.
The Study of the Electronic Structure of ZnS Doped With Co by Electron Microprobe
Authors: Spolnik Zoya , Lawniczak-Jablonska Krystyna
Published: March 2019

X-ray valence band emission spectroscopy (XES) is one of the oldest method used for studying the electronic structure of compounds. During the last three decades the rapid development of photoelectron spectroscopy (XPS, UPS) and the use of these techniques for studies of electronic structure has diverted attention from XES, However, interest in XES has been revived recently as a result of progress made in the experimental technique and the availability of the synchrotron radiation. An important advantage of XES is that, in compounds, this technique projects the density of states (DOS) at the site of emitting atom. To our knowledge, in spite of broad interest in studies of the electronic structure of diluted magnetic semiconducting (DMS) crystals, XES was not applied to this problem. In this work, we present the first measurements of the L-emission spectra of ZnS doped with Co. The partial substitution of the Zn-cations by magnetic Co atoms results in hybridisation of the 3d-states of Co with sp band of the host semiconductor.
Application of Xrf to the Detection and Estimation of Metals in Toxicological Specimens
Authors: Rendle D. F. , Taylor J. F.
Published: March 2019

The Metropolitan Police Forensic Science Laboratory is faced from time to time with cases which require the detection and estimation of metals in biological matrices. These cases generally concern instances, allegations or threats of poisoning and require the analysis of either foodstuffs or body fluids, or both. The elements of particular interest are antimony, arsenic, bismuth, cadmium, lead, mercury, and thallium.
Performance Evaluation of Free-Space Fibre Optic Detection in a Lab-on-Chip for Microorganism
Authors: Kamuri Mohd Firdaus , Abidin Zurina Zainal , Jun Lee Hao , Yaacob Mohd Hanif , Hamidon Mohd Nizar Bin , Yunus Nurul Amziah Md , Kamaruddin Suryani
Published: March 2019

This paper describes the development of a lab-on-chip (LOC) device that can perform reliable online detection in continuous-flow systems for microorganisms. The objective of this work was to examine the performance of a fibre optic detection system integrated into a LOC device. The microfluidic system was fabricated using dry film resist (DFR), integrated with multimode fibre pigtails in the LOC. Subsequently, the performance of the fibre optic detection was evaluated by its absorbance spectra, detection limit, repeatability and reproducibility, and response time. The analysis was carried out using a constant flow rate for three different types of microorganisms which are Escherichia coli, Saccharomyces cerevisiae, and Aeromonas hydrophila. Under the experimental conditions used in this study, the detection limit of 1.0×105 cells/mL for both A. hydrophila and E. coli, while a detection limit of 1.0×106 cells/mL for S. cerevisiae cells were measured. The results also revealed that the device showed good repeatability with standard deviations less than 0.2 for A. hydrophila and E. coli, while standard deviations for S. cerevisiae were larger than 1.0. The response times for A. hydrophila, E. coli, and S. cerevisiae were 104 s, 122 s, and 78 s, respectively, although significant errors were recorded for all three species for reproducibility experiment. It was found that the device showed generally good sensitivity, with the highest sensitivity towards S. cerevisiae. These findings suggest that an integrated LOC device, with embedded multimode fibre pigtails, can be a reliable instrument for microorganism detection.
Line-End Voltage and Voltage Profile along Power Distribution Line with Large-Power Photovoltaic Generation System
Authors: Matsumura Toshiro , Tsukamoto Masumi , Tsusaka Akihiro , Yukita Kazuto , Goto Yasuyuki , Yokomizu Yasunobu , Tatewaki Kento , Iioka Daisuke , Shimizu Hirotaka , Kanazawa Yuuki , Ishikawa Hiroyuki , Matsuo Akimori , Iwatsuki Hideki
Published: March 2019

In recent years, the introduction of the photovoltaic generation system (PV system) has been increasing by promoting the use of renewable energy. It has been feared that the reverse current from the PV system may cause an unacceptable level of voltage rise at the interconnection node in the power distribution system. This paper discusses the effects of the reverse current on the voltage rise and fall characteristics of the interconnection node and the voltage profiles along the power distribution line. When the line current on the circuit is small, the voltage on the line monotonically increases from the sending end to the receiving end. When a relatively large current flows, it causes a voltage reduction near the distribution substation. Furthermore, on the basis of the voltage aspects in the power distribution system with a large PV system, the allowable limits of the line current and the output power from PV system are investigated.
Immunohistochemical Study of Antioxidant Enzymes Regulated by Nrf2 in the Models of Epileptic Seizures (KA and PTZ)
Authors: Munguía-Martínez María Fernanda , Nava-Ruíz Concepción , Ruíz-Díaz Amairani , Díaz-Ruíz Araceli , Yescas-Gómez Petra , Méndez-Armenta Marisela
Published: March 2019

Epilepsy is a neurological disorder characterized by recurrent spontaneous seizures due to an imbalance between cerebral excitability and inhibition, with a tendency towards uncontrolled excitability. Epilepsy has been associated with oxidative and nitrosative stress due to prolonged neuronal hyperexcitation and loss neurons during seizures. The experimental animal models report level of ATP diminished and increase in lipid peroxidation, catalase, and glutathione altered activity in the brain. We studied the immunohistochemical expression and localization of antioxidant enzymes GPx, SOD, and CAT in the rat brains treated with KA and PTZ. A significant decrease was observed in the number of immunoreactive cells to GPx, without significant changes for SOD and CAT in KA-treated rats, and decrease in the number of immunoreactive cells to SOD, without significant changes for GPx and only CAT in PTZ-treated rats. Evident immunoreactivity of GPx, SOD, and CAT was observed mainly in astrocytes and neurons of the hippocampal brain region in rats exposed at KA; similar results were observed in rats treated with PTZ at the first hours. These results provide evidence supporting the role of activation of the Nrf2 antioxidant system pathway against oxidative stress effects in the experimental models of epileptic seizures.
Design and Real-Time Implementation of a 3-Stage CnW Heading System on an Ubuntu Linux-Embedded Board
Authors: Vista IV Felipe P. , Chong Kil To
Published: March 2019

This paper describes the design and real-time implementation of a proposed algorithm for deriving an accurate heading system by fusing data from various inexpensive sensor devices that is comparable to more expensive maritime navigation systems. The proposed algorithm is a 3-Stage Classification N’ Weighing (CnW) Heading System with forward azimuth (FAz) and extended Kalman filter (EKF). Data from three Global Positioning System devices, an inertial measurement unit, and an electronic compass were fed into the algorithm that can be generally described as Classification N’ Weighing-Stage 1 → forward azimuth → Classification N’ Weighing-Stage 2 → extended Kalman filter → Classification N’ Weighing-Stage 3. The proposed algorithm is shown to be comparably accurate as an expensive marine navigation system, and it has less processing time compared to our previous work. The Qt-anywhere-based system developed on a Linux desktop was successfully downloaded onto an Ubuntu Linux-embedded board for real-time implementation. Important notes related to device naming problems when deploying the system on a Linux-embedded board are also given as reference for those interested to address it.
Robust Stabilization of Extended Nonholonomic Chained‐Form Systems with Dynamic Nonlinear Uncertain Terms by Using Active Disturbance Rejection Control
Authors: Chen Hua , Sun Xiaoying , Xu Shen , Wang Yuxuan
Published: March 2019

In this paper, the stabilization problem of nonholonomic chained‐form systems is addressed with uncertain constants. In this paper, the active disturbance rejection control (ADRC) is designed to solve this problem. The proposed control strategy combines extended state observer (ESO) and adaptive sliding mode controller. The control of nonholonomic chained‐form systems with dynamic nonlinear uncertain terms and uncertain constants is first discussed in this paper. In comparison with existing methods, the proposed method in this paper has better performance. It is proved that, with the application of the proposed control strategy, semiglobal finite‐time stabilization of the systems is achieved. An example is given to illustrate the effectiveness of the proposed method.
Field Pea (Pisum sativum L.) Variety Development for Moisture Deficit Areas of Eastern Amhara, Ethiopia
Authors: Kindie Yirga , Bezabih Aemiro , Beshir Wubeshet , Nigusie Zinabu , Asemamaw Zelalem , Adem Antenh , Tebabele Birke , Kebede Genet , Alemayehu Tesfay , Assres Fentaw
Published: March 2019

Twelve field pea genotypes were evaluated in seven environments in Eastern Amhara in main production season (2010-2012). The objective of this trial was to identify stable and high yielding field pea genotype for production in Eastern Amhara. The trial was conducted using randomized complete block design with three replications. Combined analysis of variance for grain yield revealed that genotypes, environments, and genotype by environment interaction effect were highly significant (P ≤ 0.01). The environments, GEI, and genotypes were accounted for 77.47%, 13.83%, and 4.37%, of the total sum squares, respectively, indicating that field pea grain yield was significantly affected by the changes in the environment, followed by GEI and genotypic effect. The candidate genotype, EH-03-002, showed 14.42% and 44.87% yield advantage over the standard and local checks, respectively. Considering the seven environments data and field performance evaluation during the variety verification trial, the National Variety Releasing Committee has approved the official release of EH-03-002 with the vernacular name of “Yewaginesh” for moisture deficit areas of Wag Lasta and similar agroecologies.
Next Generation Emergency Services Based on the Pan-European Mobile Emergency Application (PEMEA) Protocol: Leveraging Mobile Positioning and Context Information
Authors: Sedlar Urban , Winterbottom James , Tavcar Bostjan , Sterle Janez , Cijan Jaka , Volk Mojca
Published: March 2019

In this paper, we analyze requirements of next generation 112 emergency services in the era of ubiquitous mobile devices and sensors and present the design, implementation, and piloting results of our testbed, which was developed within the H2020 project NEXES. The system leverages a multihop location-aware PEMEA routing network that finds the geographically closest responsible public service answering point (PSAP) and supports cross-border application roaming. Our reference mobile implementation utilizes multiple device and network-based positioning technologies, which, combined, both outperform traditional cell-tower based positioning and provide a means for detecting fraudulent calls. The system is extensible and can establish a variety of communication channels after the initial emergency session is set up; we demonstrate this with an interoperable WebRTC-based video call. The obtained results demonstrate the viability and flexibility of PEMEA-based over-the-top emergency services, show high user acceptance when comparing them with existing solutions, and thus pave the road for further rollout of such systems.
Compound Phyllanthus urinaria L Inhibits HBV-Related HCC through HBx-SHH Pathway Axis Inactivation
Authors: Li Yun , Jiang Mingjie , Li Mingshun , Chen Yingjie , Wei Chunshan , Peng Lisheng , Liu Xinliang , Liu Zhen , Tong Guangdong , Zhou Daqiao , He Jinsong
Published: March 2019

Compound Phyllanthus urinaria L (CP) is a traditional formula widely used in clinical practice for hepatocellular carcinoma (HCC), especially HBV-related HCC. HBx, HBV X gene encoded X protein, has positive correlation with the abnormal SHH pathway in HBV-related HCC. So, we predicted that CP has the capability of anti-HBV-related HCC maybe via inactivating the HBx-Hedgehog pathway axis. HepG2-HBx cells, HBx overexpression, were treated with CP (70μg/ml and 35 μg/ml, respectively) for 48 hours and the mice which received the HepG2-HBx cells were treated with CP (625mg/kg and 300 mg/kg, respectively) for 17 days to evaluate the effect of CP on HBV-related HCC. HBx could accelerate HepG2 cells proliferation, clone formation, and migration in vitro and also could strengthen tumor growth in mice. However, CP could significantly decrease HepG2-HBx cells proliferation, clone formation, and migration in vitro and also could inhibit tumors growth in mice in a dose-dependent manner. Mechanism studies suggested that HBx upregulated the mRNA and proteins expression of Sonic hedgehog (SHH), transmembrane receptor patched (PTCH-1), smoothened (SMO), oncogene homolog transcription factors-1 (GLI-1), and oncogene homolog transcription factors-2 (GLI-2), which are compositions of the SHH pathway. CP could inhibit the mRNA and proteins expression of SHH, PTCH-1, GLI-1, and HBx. It may be one of the underlying mechanisms of CP to delay the HBV-related HCC development through the HBx-SHH pathway axis inactivation.
Transmission Estimation by Complex Assumption with Occlusion Handling
Authors: Liu Jiantao , Yang Xiaoxiang , Zhu Mingzhu , He Bingwei
Published: March 2019

Transmission estimation is a critical step in single‐image dehazing. The estimate of each pixel describes the portion of the scene radiance that is degraded by hazing and finally reaches the image sensor. Transmission estimation is an underconstrained problem, and, thus, various assumptions, priors, and models are employed to make it solvable. However, most of the previous methods did not consider the different assumptions simultaneously, which, therefore, did not correctly reflect the previous assumptions in the final result. This paper focuses on this problem and proposes a method using an energy function that clearly defines the optimal transmission map and combines the assumptions from three aspects: fidelity, smoothness, and occlusion handling, simultaneously. Fidelity is measured by a novel principle derived from the dark channel prior, smoothness is described by the assumption of piecewise smoothening, and occlusion handling is achieved based on a new proposed feature. The transmissions are estimated by searching for the optimal solution of the function that can retain all the employed assumptions simultaneously. The proposed method is evaluated on the synthetic images of two datasets and various natural images. The results show that there is remarkable fidelity and smoothness in the transmission and that a good performance is exhibited for haze removal.
Experimental Study and Numerical Simulation of Dynamic Stress‐Strain of Directional Blasting with Water Jet Assistance
Authors: Su Dengfeng , Zheng Dandan , Zhao Lingang
Published: March 2019

Effective control of the explosive energy and the propagation direction of blast‐induced crack and minimizing damage of remaining rock mass are the main purposes of directional‐controlled blasting. In this paper, the experimental test on blast strain fields affected by water jet slot and blasthole wall protection material is conducted. Next, the FEM software ANSYS/LSDYNA is used to simulate the blast‐induced crack propagation and the blast stress wave transmission of different types of blasthole, and the distribution and evolution law of dynamic blast stress are also analyzed. The results indicate that the existence of blasthole wall protection material is not only beneficial to the “guiding effect” of blast‐induced crack propagation of water jet slot but also beneficial to reduce blast‐induced damage of remaining rock mass. Besides, the bigger Dm/rb is, the weaker the “guiding effect” and “blasthole wall protection effect” by water jet slot and wall protection material are.
Sirolimus: A Successful Medical Treatment for Head and Neck Lymphatic Malformations
Authors: Curry Steven , Logeman Andrew , Jones Dwight
Published: March 2019

Lymphatic malformations are abnormalities that arise in the developing lymphatic system, most frequently presenting in the head and neck. They are typically treated with sclerotherapy, laser therapy, or surgery for localized lesions. Sirolimus, an inhibitor of the mammalian target of rapamycin, is a relatively new medical therapy for the treatment of vascular malformations. This case report presents the improvements and complications seen in a female infant who was diagnosed with a large lymphatic malformation on prenatal ultrasound and has been treated with sirolimus during the first 9 months of life.
Binomial Representation of Cryptographic Binary Sequences and Its Relation to Cellular Automata
Authors: Cardell Sara D. , Fúster-Sabater Amparo
Published: March 2019

The binomial sequences are binary sequences that correspond to the diagonals of the binary Sierpinski’s triangle. They have fancy properties such that all the sequences with period equal to a power of 2 can be represented as the sum of a finite set of binomial sequences. Other structural properties of these sequences (period, linear complexity, construction rules, or relations among the different binomial sequences) have been analyzed in detail. Furthermore, this work enhances the close relation between the binomial sequences and a kind of Boolean networks, known as linear cellular automata. In this sense, the binomial sequences exhibit the same behavior as that of particular Boolean networks. Consequently, the binomial sequences can be considered as primary tools for generating other more complex Boolean networks with applications in communication systems and cryptography.
Recommendation of Crowdsourcing Tasks Based on Word2vec Semantic Tags
Authors: Pan Qingxian , Dong Hongbin , Wang Yingjie , Cai Zhipeng , Zhang Lizong
Published: March 2019

Crowdsourcing is the perfect show of collective intelligence, and the key of finishing perfectly the crowdsourcing task is to allocate the appropriate task to the appropriate worker. Now the most of crowdsourcing platforms select tasks through tasks search, but it is short of individual recommendation of tasks. Tag-semantic task recommendation model based on deep learning is proposed in the paper. In this paper, the similarity of word vectors is computed, and the semantic tags similar matrix database is established based on the Word2vec deep learning. The task recommending model is established based on semantic tags to achieve the individual recommendation of crowdsourcing tasks. Through computing the similarity of tags, the relevance between task and worker is obtained, which improves the robustness of task recommendation. Through conducting comparison experiments on Tianpeng web dataset, the effectiveness and applicability of the proposed model are verified.
Treatment of a Subacute Locked Thumb Metacarpophalangeal Joint with Sesamoid Entrapment
Authors: Carroll John J. , McClain William D. , Nuelle Julia A. V.
Published: March 2019

Introduction. Locked thumb metacarpophalangeal (MCP) joints due to entrapped radial sesamoids are rare injuries that commonly require open reduction, especially when the injury is delayed in presentation. Case Presentation. We present a case of a 24-year-old female with a subacute thumb MCP joint subluxation due to an incarcerated radial sesamoid. She underwent successful closed reduction but had persistent pain and difficulty gripping large objects necessitating eventual open volar plate repair despite therapy. She was able to achieve full motion, with little pain and disability, after undergoing delayed volar plate repair. Discussion. Delayed volar plate repair may be considered for those patients who fail to improve with conservative management and occupational therapy after a successful closed reduction for thumb MCP joint subluxation due to an incarcerated radial sesamoid.
Immobilization of Protein A on Monodisperse Magnetic Nanoparticles for Biomedical Applications
Authors: Thanh Bui Trung , Van Sau Nguyen , Ju Heongkyu , Bashir Mohammed J. K. , Jun Hieng Kiat , Phan Thang Bach , Ngo Quang Minh , Tran Ngoc Quyen , Hai Tran Hoang , Van Pham Hung , Nguyen Tan Tai
Published: March 2019

We presented synthesis and physical characterization of iron oxide magnetic nanoparticles (Fe3O4) for biomedical applications in the size range of 10-30 nm. Magnetic nanoparticles were synthesized by the coprecipitation method, and the particles’ size was controlled by two different injection methods of sodium hydroxide (NaOH). The synthesized magnetic nanoparticles were then modified by using series of linkers including tetraethyl orthosilicate (TEOS), 3-aminopropyltriethoxysilane (APTES), and glutaraldehyde (GA) to generate the structure of Fe3O4/SiO2/NH2/CHO, which can be used for immobilization of protein A. Additionally, we used transmission electron microscopy (TEM), X-ray powder diffraction (XRD), vibrating-sample magnetometry (VSM), and Fourier-transform infrared spectroscopy (FTIR), for characterization of properties and structure of the nanoparticles. An immobilization of protein A on magnetic nanoparticles was studied with a UV-Vis spectrum (UV-Vis) and fluorescence electron microscopy and Bradford method. Results showed that an XRD spectrum with a peak at (311) corresponded to the standard peak of magnetic nanoparticles. In addition, the magnetic nanoparticles withd≥30 nm have higher saturation magnetizations in comparison with the smaller ones withd≤10 nm. However, the smaller magnetic nanoparticles offered higher efficiency for binding of protein A, due to the high surface/volume ratio. These particles with functional groups on their surface are promising candidates for biomedical applications, e.g., drug delivery, controlled drug release, or disease diagnosis in point-of-care test.
Acoustic Supercoupling in a Zero-Compressibility Waveguide
Authors: Esfahlani H. , Byrne M. S. , McDermott M. , Alù A.
Published: March 2019

Funneling acoustic waves through largely mismatched channels is of fundamental importance to tailor and transmit sound for a variety of applications. In electromagnetics, zero-permittivity metamaterials have been used to enhance the coupling of energy in and out of ultranarrow channels, based on a phenomenon known as supercoupling. These metamaterial channels can support total transmission and complete phase uniformity, independent of the channel length, despite being geometrically mismatched with their input and output ports. In the field of acoustics, this phenomenon is challenging to achieve, since it requires zero-density metamaterials, typically realized with waveguides periodically loaded with membranes or resonators. Compared to electromagnetics, the additional challenge is due to the fact that conventional acoustic waveguides do not support a cut-off for the dominant mode of propagation, and therefore zero-index can be achieved only based on a collective resonance of the loading elements. Here we propose and experimentally realize acoustic supercoupling in a dual regime, using a compressibility-near-zero acoustic channel. Rather than engineering the channel with subwavelength inclusions, we operate at the cut-off of a higher-order acoustic mode, demonstrating the realization and efficient excitation of a zero-compressibility waveguide with effective soft boundaries. We experimentally verify strong transmission through a largely mismatched channel and uniform phase distribution, independent of the channel length. Our results open interesting pathways towards the realization of extreme acoustic parameters and their implementation in relevant applications, such as ultrasound imaging, acoustic transduction and sensing, nondestructive evaluation, and sound communications.
A Scheduling Method of Cross-Layers Optimization of Polling Weight for AOS Multiplexing
Authors: Zhao Yuntao , Bo Bo , Feng Yongxin
Published: March 2019

The core mechanism of Advanced Orbit System (AOS) mainly contains the packet channel multiplexing and the virtual channel multiplexing. The multiplexing efficiency and frame time directly affect the performance of the AOS and even the whole system. In this paper, in order to optimize AOS multiplexing performance, a scheduling method of cross-layers optimization of polling weight (CLOPW) is proposed. Different from single sublayer optimization such as the isochronous frame methods, the novel method focuses on factors related to AOS performance of two core sublayers, such as packet distribution, residual function, cache capacity, frame time, and multiplexing efficiency. We build a multiple factors framing model of finite buffer and deduce the formula of packet multiplexing efficiency based on the short correlation. Furthermore, we give the formula for the virtual channel utilization and delay of cross-layer optimization. The experimental results show that the novel scheduling method of cross-layers optimization of polling weight is higher utilization of virtual channel and lower average delay than the isochronous frame method.
Health Monitoring of Bolt Looseness in Timber Structures Using PZT-Enabled Time-Reversal Method
Authors: Zhao Ze , Chen Pengcheng , Zhang En , Lu Guoyun
Published: March 2019

A prestressed bolt connection is one of the crucial connection types in timber structures. The daily checking and maintenance of bolt connections have to be carried out in order to avoid the collapse of timber structures due to bolt looseness. Real-time health monitoring of bolt connections can not only reduce the daily maintenance cost of timber structures, but it can also avoid property loss and casualties by giving early warning if the bolt connection is loosened in timber structures. This paper proposes a method of prestress monitoring of bolt joints in timber structures by pasting lead zirconate titanate (PZT) patches on the surface of timber structures, and the time-reversal method is applied to denote the connection status of bolts in timber structures. The prestress loss index of timber structural bolts based on wavelet analysis is designed to quantify the bolt looseness of the timber structure. The experimental timber specimen was fabricated consisting of two timber panels, one bolt, and two PZT patches. One of the PZT patches acted as an actuator to emit the stress waves, and another one acted as a sensor to receive the stress wave propagating through the connection interface. The experimental results showed that the amplitude of the focused signal increases significantly with the increase of the prestress value of the bolts, which verify that the proposed method can be utilized to monitor the looseness of bolts in timber structures. The analysis results of the focused signal is proof that the prestress loss index of timber structural bolts designed based on wavelet analysis can reflect the looseness of timber structural bolts.