bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial Relations in Contextual Information for Mobile Emergency Messaging
Authors: Almagrabi Alaa , Loke Seng W. , Torabi Torab
Published: October 2013

Responding to a disaster is a process that should take the least time with high-level information. It requires human decisions that could delay the whole process, thus putting more lives at stake. However, recent technological developments improve this process by facilitating decisions within the domain. Discovering the spatial relationship can help to clarify the spatial environment for the domain. In this chapter, the authors give an overview of using spatial modelling and spatial relations for context-aware messaging with emphasis on emergency situations. They utilize various existing spatial relations recognized within the field of spatial computing such as RCC8 and Egenhofer relations. The RCC8 and Egenhofer relations are examined besides a range of spatial relations using English phrases in Mona-ont emergency ontology. The Mona-ont emergency ontology is used to describe emergency scenarios. The Mona-ont emergency ontology is employed by the Mona Emergency System (MES) that generates alert messaging services to actors within a disaster area. The authors demonstrate the validity of the Mona-ont spatial relations in describing a (fictitious) flood situation in the Melbourne CBD area. They also prescribe the structure of such context-aware messages (i.e. their content and target description) for the MES system.
Study on New Types of Environmental Protection AgSnO2 Electrical Contact Materials
Authors: Zheng Ji , Jiang Fei , Li Song Lin
Published: October 2013

AgSnO2contact materials have begun to replace toxic AgCdO materials in switching devices such as contactors and circuit breakers since 1970s [1,, which is partly due to the fact that AgSnO2materials have shown higher service lives, better welding resistance and less arc erosion in contactors of larger size [. Furthermore, the growing awareness of environmental problems makes it desirable to replace AgCdO contact materials [. However, these materials suffer from an inadequate welding behavior compared with AgCdO [. It was observed that AgSnO2made by traditional metallurgical process exhibited high overtemperatures attributed to high contact resistance caused by surface layers of accumulated SnO2, which was due to the poor wettability of SnO2grains in the silver melt in combination with their high thermal stability [6,7]. Another important point was the large size and high hardness of SnO2particle prepared by traditional process, which reduced the workability of AgSnO2contact materials [8]. In this work, the authors prepared Ti4+-doped SnO2using sol-gel technique and investigated the microstructure, size, distribution and crystallization of Ti4+-doped tin oxide grains as well as the doping effects on the electrical conductivity of these materials.
Research and Application of Heat Transfer Fluids in Solar Thermal Power
Authors: Cheng Xiao Min , Zhu Chuang , Zhang Han , Yang Xian Jie
Published: October 2013

mproving the thermophysical properties of heat transfer fluid is always a research hotspot and difficult subject in the application of solar energy for medium and high temperature. The research and application of these heat transfer fluid, including steam, heat transfer oil, molten salt, air, liquid alloy and nanofluids, were summarized in this paper. After comparing their characteristics, it is found that molten salt, air and liquid alloy have greater application and development prospects. Future research directions include extending the temperature span of operating condition, enhancing the efficiency of heat transfer and storage, lengthening service life and finding out the correlation between microstructure and related performance.
Rheological Properties and Anti-Aging Properties of PP/PP-g-AN Blends
Authors: Wang Ya Zhen , Yue Cheng E , Ma Di , Jia Wei Nan , Li Yong
Published: October 2013

The effect of PP-g-AN prepared by solid phase grafting on the blends of PP/PP-g-AN was investigated in this paper. The influence of aging testing time, PP-g-AN additives concentration, shear rate on the rheological properties and anti-aging properties of PP/PP-g-AN were mainly discussed. The results show that PP/PP-g-AN blends are pseudoplastic fluid and the presence of PP-g-AN can restrain the degradation of polypropylene when the content of PP-g-AN is in a certain range.
Self-Lubricating Behavior of ZrO2(Y2O3)-Mo-CaF2-Graphite Composite
Authors: Kong Ling Qian , Bi Qin Ling , Zhu Sheng Yu , Liu Wei Min
Published: October 2013

t is of great importance to find ways to lubricate ZrO2ceramic. In this paper, a kind of ZrO2 matrix high temperature self-lubricating compositewith addition of CaF2 and graphite as lubricants was prepared by hot-pressing. It was found that the tribological properties of ZrO2(Y2O3)-CaF2-graphiteshow a good tribological behavior both at low temperature and high temperatures. The low friction coefficients of ZrO2 (Y2O3)-Mo-CaF2-graphite at high temperatures were due to the perfect lubricity of CaMoO4 which was formed on the worn surface at high temperatures.
Parametric Study on Simulation Modeling of Diameter-Expanded Conductor
Authors: Si Jia Jun , Zhu Kuan Jun , Wan Jian Cheng , Yang Jia Lun , Liu Long , Ding Yao
Published: October 2013

So as to decrease the cost and time of the development, it is significance to solve the section instability problem of diameter-expanded conductor during the design stage. The solution is developing a finite-element simulation program for the study of section stability; however, a proper modeling method is not necessary. In this paper, the parametric study on simulation modeling of diameter-expanded conductor is carried out and through the investigation, analysis and verification; a kind of test method has been designed for the study. After a series of test under different tensions, the numbers of sheave, the position of strand jumping, the section states and the indentation states have been gotten. At last, a parametric finite-element program for strand jumping prediction has been simulated and the result shows that the code developed is reliable based on the comparison of the calculated results and the measured ones.
Analysis of Gene Expression as Marker of Relevant Metabolisms, in Three Acidithiobacillus ferrooxidans Strains, in Different Growth Conditions
Authors: Araya Gonzalo , Acosta Mauricio , Demergasso Cecilia
Published: October 2013

Acidithiobacillus ferrooxidansis a chemiolithoautotrophic Gram-negative bacterium widely spread in ambient temperature bioleaching processes. Several strains ofAt. ferrooxidanswere isolated and studied and, some time later, questions arise about whether it was a species with a wide metabolic variation or a group of closely related species. Advances in molecular biology, phylogeny and genomics have shed some light onAt. ferrooxidansstrains and allows their grouping according to their relations. However, significant challenges remains to be met, such as understanding how a particular strain faces environmental challenges and how a particular kind of adaptive response affects the growth and activity of the strain. The purpose of this study was to identify differential expression signals betweenAt. ferrooxidansstrains −with different abundances and dynamics− present in the bioleaching system at Escondida mine. Culture characterization and DNA macroarrays techniques provided some answers. Analysis of growth curves showed that IESL 32 had the highest anaerobic growth rate, while aerobic growth was similar for all strains. It was shown that though the phylogenetic analysis based on 16S rRNA sequences suggested a close relation between IESL 32 and the type strain ATCC 23270, the growth curves and the expression profile showed that the type strain and strain D2 had the closest similarity. Growth experiments under different conditions, together with the comparative analysis of gene expressions inAt. ferrooxidans, could be a springboard for future investigations of strain characterization to broaden our knowledge about adaptation, metabolic strategies, regulation and microbial diversity in industrial processes.
Conductive Filaments Produced by Aeromonas hydrophila
Authors: Castro Laura , Vera Mario , Muñoz Jesús Angel , Blázquez María Luisa , González Felisa , Sand Wolfgang , Ballester Antonio
Published: October 2013

Aeromonas hydrophilais a facultative anaerobe which, under conditions of oxygen depletion, is able to respire iron (III). Scanning electron microscopy (SEM) and conducting-probe atomic force microscopy (AFM) revealed the presence of filaments between cells and cell-substrate and their conductive nature. These results indicate that the pili ofA. hydrophilamight serve as biological nanowires, transferring electrons from the cell to the surface of Fe (III) oxides. Conductive pili could also play a role in bacterial interactions and in inter/intra species signalling, and could lead to biotechnological approaches for novel materials.
Effect of Increased Acid Concentration on the Microbial Population Inhabiting an Industrial Heap Bioleaching Plant
Authors: Zepeda Victor J. , Cautivo Dina , Galleguillos Pedro A. , Salazar Camila N. , Velásquez Antonio , Pinilla Carlos , Demergasso Cecilia
Published: October 2013

The material treated in the industrial heap bioleaching plant at Escondida Mine includes sulfide, oxide and mixtures of run of mine ore (ROM) with 5% of total copper average grade. The design of the heap considers seven lifts of eighteen meters height each. Nowadays, the heap is being operated with ore loaded in the second and third lifts. The amount of acid required for the process can be increased by increasing the height of the heap and also by the characteristics of the ore. This effect can be attributed to the increase of contact time between ore and solution. The goal of this work was to assess the effect of using raffinate solution with elevated concentration of acid on a microbial culture obtained from process solutions. Reactor tests of culture grown in industrial raffinate solution were performed and DNA and RNA were extracted for qPCR and RT-qPCR analyses, respectively. A design of experiment (DOE) was considered to determine the number of replicates in order to assess the effect of two concentrations of sulfate (80 and 100 g/L) and two incubation temperatures (30 and 45 °C). In addition, analysis of the Most Probable Number (MPN) of iron and sulfur oxidizing organisms and oxidation tests were used to determine the microbial activity in the tests. The results obtained from the DOE showed that acid, temperature and the interaction of temperature and energy source had a significant effect on the microbial activity. Both iron and sulfur oxidizing activities decreased when acid was added at elevated concentration. By other hand, molecular analyses showed differences in levels of specific concentrations of microorganisms and the expression of 16S rRNA gene of the different species thriving in the culture tests.
Effects of Several Parameters on Nickel Extraction from Laterite Ore by Direct Bioelaching Using Aspergillus niger and Acid Rock Drainage from Coal Mine as an Organic Substrate
Authors: Mubarok M. Zaki , Kusuma Hardy , Minwal W.P. , Chaerun Siti Khodijah
Published: October 2013

Aspergillus niger is a prominent fungi that has been used for bioleaching of nickel laterite ore and commercial production of citric acid. Series of shake flask bioleaching assays have been conducted to study the effects of ore type, ore particle size distribution, solid percentage, and substrate volume percentages as well as sulphur addition on the nickel extraction from Indonesian laterite ore. Acid rock drainage (ARD) from local coal mine was used as a substrate for carbon and nutrient sources of the fungus. The results show that saprolite ore exhibits a better leaching with fungal metabolic acids than limonite. The highest nickel extraction of saprolite ore was 43%, which was obtained from the shake flask bioleaching assays with ore particle size distribution of -60+80 mesh, pulp density of 2.5%, and ARD substrate volume percentage of 10%, after 24 days of incubation. For both saprolite and limonite ore samples, coarse particle size ditribution of -60+80 mesh provides a better nickel extraction than the finer ore particle size. The addition of potato dextrose agar and fresh innoculum after 16 incubation days generated a re-increase of nickel extraction, indicating the refreshment of the active fungus. Based on the results, it was found that Aspergilus niger growth can take place with an organic substrate of liquid ARD obtained from coal mining area.
Selective Metal Removal from Scandinavian Mine Waters Using Novel Biomineralization Technologies
Authors: Kay Catherine M. , Hedrich Sabrina , Johnson D. Barrie
Published: October 2013

Mine drainage waters are widely regarded as environmental pollutants, but they are also potential sources of valuable transition metals, such as zinc, copper and cobalt. This article describes the laboratory application of continuous flow modular bioreactor systems, one oxidative and the other reductive, for the selective precipitation of metals from metal-rich acidic mine waters.
Field Scale Phytoremediation Experiments on a Former U Mining Site and Further Processing of the Plant Material
Authors: Mirgorodsky Daniel , Ollivier Delphine , Jablonski Lukasz , Merten Dirk , Willscher Sabine , Wittig Juliane , Büchel Georg , Werner Peter
Published: October 2013

The remediation of large heavy metal/radionuclide (HM/R) contaminated areas by conventional ex-situ techniques (excavation or chemical treatment/-stabilization) is expensive, and low cost strategies with a long-term stabilization effect of such sites are a task of next years research. Phytoremediation can be an alterative solution and sustainable technology since low treatment costs make it feasible even for such sites. Field scale investigation is applied to an area of the former uranium mining in East Thuringia, Germany. On this area, a low grade uranium ore leaching dump was situated, which was later removed during the remediation process of the site. Now, an underground remains that is slightly to moderately contaminated with heavy metals and radionuclides (HM/R) with restrictions of land use. Concepts for remediation of HM/R-contaminated sites and for the subsequent utilization of the HM/R-loaded plant residues are developed in a joint project. Plant experiments with Triticale, Helianthus annuus,Brassica juncea and Sorghumbicolor were performed revealing the influence of biological additives (mycorrhiza, HM-resistant streptomyces) and soil amendment strategies (increasing pH and organic matter) on biomass production and plant tolerance to heavy metals. The addition of mycorrhiza and streptomyces (MS) had a significant effect on biomass, and decreased the bioavailable parts of HM/R (e.g. Ni, Sr, U) in soil in comparison to untreated polluted soil with all studied plants. In lysimeter experiments it was figured out, that the different soil improvement strategies, addition of MS and of calcareous top soil (MIX) resulted in a reduction of the concentration of contaminants in the seepage water, as well as of the seepage water rates and loads, thus decreasing the risk of groundwater contamination. Finally, the processing of the heavy metal loaded plant residues was investigated by different methods. Fermentation experiments carried out with Solanum tuberosum and Secale cereale achieved good results compared with industrial standards. Remaining plant parts can be processed in a biogas process, or combusted. Fermentation sludges and combustion ashes act as sinks for HM/R. As results of the project, phytoremediation is a convenient method for the stabilization and remediation of large sites with slight to medium contaminations, and a further utilization of the plant residues by fermentation and biogas production is feasible.
Characterization of U(VI) Sorption and Leaching on Clay Supported Biomass Sorbents
Authors: Olivelli Melisa Soledad , Di Gregorio Daniel , Huck Hugo , Niello Jorge Fernández , Torres Sánchez Rosa María , Curutchet Gustavo
Published: October 2013

In previous studies was demonstrated that matrixes generated from fungal biomass and a montmorillonite (BMMTs) are efficient as biosorbentes in batch uranium removal systems. The objective of this article is to evaluate the U(VI) sorption capacity of BMMT in continuous systems for its removal from effluents and to determine the reusability of the sorbent and the recovery of the uranium testing different leaching solutions. Upflow BMMT columns were performed in order to optimize the system for continuous sorption techniques. For upflow columns, the maximum total amount of U(VI) retained was 75 mg U(VI) / g BMMT. Treatment of U(VI) loaded BMMTs with leaching solutions allowed calculating U(VI) extraction percentages. These results indicated the possibility of recycling the sorbent after processes of U(VI) sorption and that the use of clay supported biomass sorbents in upflow columns presented strong potential for uranium retention.
Recovery of Metals and Stabilization of Arsenic from (Bio-)Leaching Operations by Engineered Biological Processes
Authors: Gonzales Contreras Paula , Olde Weghuis Martijn , Weijma Jan , Buisman Cees N.J.
Published: October 2013

This paper focuses on the application of biotechnological stabilization of arsenic from (bio-) leaching operations. One of the latest applications of the Thioteq technology is arsenic immobilization. The Thioteq-scorodite biorecovery reactor is an aerobic system to immobilise arsenic in bio-scorodite crystals. In this patented process, biological arsenite oxidation, biological ferrous iron oxidation and crystallisation reactions are simultaneously taking place. Bio-scorodite crystals can be easily harvested by sedimentation due to their relative large size of up to 160 μm. This biogenic material is classified as non-hazardous due to its very low arsenic leaching rates. Furthermore, bioscorodite crystals resemble the colour, crystal morphology, iron and arsenic content, structural water of the mineral scorodite. The operational costs related to scorodite bio-crystallization can be reduced at least 50% compared to chemical precipitation because the use of biological reactions to induce the crystallization of scorodite and the good stability properties of the produced crystals. The Thioteq-scorodite process is a reliable cost effective solution to arsenic removal and immobilization by using biological processes. The stabilization of arsenic in the form of biologically produced scorodite is an attractive technology for the compact and safe immobilization of arsenic from medium to high concentrations of arsenic in acidic process streams.
Influence of Tool Path Orientation on the Surface Roughness when End Ball Milling Rounded Surfaces
Authors: Beňo Jozef , Mikó Balázs , Maňková Ildikó , Vrabel' Marek
Published: October 2013

Paper deals with relationships affecting surface roughness in three dimensional milling. Because of definite curvature of the machined surface, three milling strategies based on single direction have been examined in end ball milling process. Research is based on fragmentation of the definite surface curvature into form of the patches being machined. Patches have been set through normal vectors and related axes of motion of the end ball milling cutters. Surface quality has been identified under influence of cutting speed, feed rate and side step of milling cutters. Simple geometrical models of the resultant cusp height are compared with the measured data.
Investigation of Surface Roughness while Ball Milling Process
Authors: Bilek Ondrej , Sámek David , Šuba Oldřich
Published: October 2013

Increasing urge to raise production rate and production quality in the industry brings new requests and challenges. One of them is demand for accuracy and precision of produced parts. Especially in the CNC machining, where the expectations are high, the companies face new issues. Therefore, it is very important to recognize, understand and cope with the technological factors influencing the production accuracy and surface quality of CNC machined parts.
Effect of the Working Diameter to the Surface Quality in Free-Form Surface Milling
Authors: Mikó Balázs , Beňo Jozef
Published: October 2013

The article presents the changing of the working diameter (effective diameter) and its effect to the surface roughness based on milling experiments of a test part in 3D milling of free-form surfaces. The position of the surface and the step depth determine the effective diameter, in case of constant revolution of the tool, the actual cutting speed and the minimal removable chip thickness will change. The article presents the result of the application of the constant cutting speed and feed per tooth.
Mathematical Simulation of Kinematics of Vibrating Boiling Granular Medium at Treatment in the Oscillating Reservoir
Authors: Fedorovich Vladimir A. , Mitsyk Andrew V.
Published: October 2013

The results of mathematic simulation of directed motion of the circulating flow of granulated working medium in the oscillating reservoir of finishing-grinding vibration machine are given. The model is based on the physical phenomenon, at which the granulated medium changes into vibro-boiling state clue to the action of vibrations. The solutions of Navier-Stokes implicated equations give the expressions of Bessel functions and their integral transformations. The model solutions ground the complex cycloid-trochoid nature of working medium kinematics on the vibration treatment operations and allow to determine the velocities of displacements of medium flows in any point of the reservoir. It is necessary for determination of the technological parameters and required equipment as well as their complex influence on the vibration treatment effectiveness. The zones of reservoir with increased impulse loading at combining the schemes of energetic action into the working medium and processed products are observed.
Wear Rate of CBN Cutting Tool in Hard Turning of 100Cr6 Bearing Steel
Authors: Ráczkövi László
Published: October 2013

The examination of wear and tool life of CBN cutting tools which are used for hard turning is a emphasized research theme, since the significant proportion of cost of machining associated with cutting tool. In this article we examined the wear of low CBN content cutting tool in case of hard turning of 100Cr6 bearing steel (HRC=62±2). The experiments were carried out with constant depth of cut and feed rate at three different cutting speeds. The flank wear of CBN inserts were measured after predetermined number of passes. The measured flank wear values were described as a function of cutting time and the calculated wear rate as a function of flank wear.The average wear rate were shown at three different cutting speeds.
Fabrication of Light-Emitting Diodes with Dislocation-Related Luminescence by Annealing of Electron-Irradiated Silicon
Authors: Sobolev N.A. , Aruev P.N. , Kalyadin Anton E. , Shek Elena I. , Zabrodski Vladimir , Loshachenko A.S. , Shtel'makh K.F. , Vdovin V.I. , Medvids Artur , Xiang Lue Lue , Yang De Ren
Published: October 2013

Structural defects induced by electron irradiation of n-Cz-Si wafers were identified. The influence of the annealing conditions in a chlorine-containing atmosphere on the structural and luminescent properties of the samples was examined and the optimal annealing conditions were found. Light-emitting diodes based on electron-irradiated and high-temperature-annealed wafers were fabricated by a vapour-phase epitaxy technique and their luminescence properties were studied. A high-intensity dislocation-related D1 line was observed at 1.6 μm in the room-temperature electroluminescence spectrum.
Multiple Proton Implantations into Silicon: A Combined EBIC and SRP Study
Authors: Kirnstötter Stefan , Faccinelli Martin , Jelinek Moriz , Schustereder Werner , Laven Johannes G. , Schulze Hans Joachim , Hadley Peter
Published: October 2013

Protons with energies of 1 MeV and 2.5 MeV were implanted into a p-doped silicon wafer and then the wafer was annealed at 350 °C for one hour. This resulted in two n-doped layers in the otherwise p-doped sample. The carrier concentration was measured using spreading resistance profiling while the positions of the four pn-junctions were measured using electron beam induced current measurements. The carrier concentration is not limited by the available hydrogen but by the concentration of suitable radiation induced defects.
Characterization of Electrical Contacts on Silicon (100) after Ablation and Sulfur Doping by Femtosecond Laser Pulses
Authors: Saring Philipp , Baumann Anna Lena , Kontermann Stefan , Schade Wolfgang , Seibt Michael
Published: October 2013

This paper investigates the influence of different number of laser pulses on contact behavior and conductivity of the surface layer of femtosecond laser microstructured, sulfur-doped silicon. Single shot laser processed silicon (Pink Silicon) is characterized by low surface roughness, whereas five shot laser processed silicon (Grey Silicon) has an elevated sulfur content with a surface roughness low enough to maintain good contacting. To laterally confine the laser induced pn-junction part of the Grey Silicon sample surface is etched off. The etching depth is confirmed to be sufficient to completely remove the active n-type sulfur layer. While Pink Silicon shows little or no lateral conductivity within the laser processed layer, Grey Silicon offers acceptable conductivity, just as expected by the fact of having incorporated a higher sulfur dopant content. Recombination dominates the irradiated regions of Pink Silicon and suppresses excess charge carrier collection. Grey Silicon, while showing sufficient lateral conductivity, still shows regions of lower conductivity, most likely dominated by the laser irradiation-induced formation of dislocations. According to our results, the optimum laser pulse number for electrical and structural properties is expected to be in the range between one and five laser pulses.
Study of Photovoltage Decays in Nanostructured Ge/Si
Authors: Korotchenkov Oleg , Nadtochiy Artem , Schlosser Viktor
Published: October 2013

Motivated by the importance of the oxidized silicon layers, we have studied the surface photovoltage (SPV) transients in nanoislands of GexSi1x on silicon and oxidized Si surfaces. It is shown that the SPV decays can be approximated by the stretched-exponential form, with the β values ranging from 0.3 to 0.6 for the islands grown on oxide-covered Si substrates and from 0.5 to 1 for the ones placed on bare Si. On this basis, a simple qualitative model is proposed that takes into account a donor-and acceptor-like interface states at the GeSi/SiO2 and Si/SiO2 interface, which act as recombination centers with densities dependent on the GeSi coverage. These results can be used to improve the functionality of photoelectric devices based on Ge/Si.
Vacancy-Related Defects in Ge Doped with Tin
Authors: Khirunenko Lyudmila I. , Pomozov Yurii V. , Sosnin Mikhail G. , Abrosimov Nikolai V. , Riemann Helge
Published: October 2013

It has been found that isolated V20 and V20 localized near tin atoms are formed in Ge doped with tin. Simultaneously with V20 annealing, the appearance of absorption spectra consisting of sharp lines was observed. The defect to which the spectra found corresponds has hydrogen-like properties. The distances between the lines in spectrum are in good agreement with those predicted by effective-mass theory. The formation of the defect found does not depend on oxygen concentration. An appearance of Fano resonance in the region of continuum was detected in addition to intracenter transitions of the defect. The defect found was identified as SnV20Ga.
First-Principles Analysis on Interaction between Dopant (Ga, Sb) and Contamination Metal Atoms in Ge Crystals
Authors: Yamato Tatsunori , Sueoka Koji , Maeta Takahiro
Published: October 2013

The lowest energetic configurations of metal impurities in 4th row (Sc - Zn), 5th row (Y - Cd) and 6th row (Hf - Hg) elements in Ge crystals were determined with density functional theory calculations. It was found that the substitutional site is the lowest energetic configuration for most of the calculated metals in Ge. The most stable configurations of dopant (Ga, Sb) - metal complexes in Ge crystals were also investigated. Following results were obtained. (1) For Ga dopant, 1st neighbor T-site is the most stable for metals in group 3 to 7 elements while substitutional site next to Ga atom is the most stable for metals in group 8 to 12 elements. (2) For Sb dopant, substitutional site next to Sb atom is the most stable for all calculated metals. Binding energies of the interstitial metal Miwith the substitutional dopant Ds were obtained by the calculated total energies. The calculated results for Ge were compared with those for Si.
Point Defects in 4H-SiC Epilayers Introduced by 4.5 MeV Electron Irradiation and their Effect on Power JBS SiC Diode Characteristics
Authors: Hazdra Pavel , Záhlava Vít , Vobecký Jan
Published: October 2013

Electronic properties of radiation damage produced in 4H-SiC by electron irradiation and its effect on electrical parameters of Junction Barrier Schottky (JBS) diodes were investigated. 4H‑SiC N‑epilayers, which formed the low‑doped N-base of JBS power diodes, were irradiated with 4.5 MeV electrons with fluences ranging from 1.5x1014 to 5x1015 cm-2. Radiation defects were then characterized by capacitance deep-level transient spectroscopy and C-V measurement. Results show that electron irradiation introduces two defect centers giving rise to acceptor levels at EC‑0.39 and EC‑0.60 eV. Introduction rate of these centers is 0.24 and 0.65 cm‑1, respectively. These radiation defects have a negligible effect on blocking and dynamic characteristics of irradiated diodes, however, the acceptor character of introduced deep levels and their high introduction rates deteriorate diode’s ON-state resistance already at fluences higher than 1x1015 cm‑2.
Electrical and Optical Characterisation of Silicon Nanocrystals Embedded in SiC
Authors: Schnabel Manuel , Löper Philipp , Canino Maria , Dyakov Sergey A. , Allegrezza Marco , Bellettato Michele , López-Vidrier Julià , Hernández Sergi , Summonte Caterina , Garrido Blas , Wilshaw Peter R. , Janz Stefan
Published: October 2013

Silicon nanocrystals (Si NCs) are a promising candidate for the top cell of an all-Si tandem solar cell with a band gap from 1.3-1.7 eV, tuneable by adjusting NC size. They are readily produced within a Si-based dielectric matrix by precipitation from the Si excess in multilayers of alternating stoichiometric and silicon-rich layers. Here we examined the luminescence and transport of Si NCs embedded in SiC. We observed luminescence that redshifts from 2.0 to 1.5 eV with increasing nominal NC size. Upon further investigation, we found that this redshift is to a large extent due to Fabry-Pérot interference. Correction for this effect allows an analysis of the spectrum emitted from within the sample. We also produced p-i-n solar cells and found that the observed I-V curves under illumination could be well-fitted by typical thin-film solar cell models including finite series and parallel resistances, and a voltage-dependent current collection function. A minority carrier mobility-lifetime product on the order of 10-10 cm2/V was deduced, and a maximum open-circuit voltage of 370 mV achieved.
ZnO Nanoparticle Formation in Si by Co-Implantation of Zn+ and O+ Ions
Authors: Privezentsev Vladimir V. , Shemukhin Andrey A. , Petrov Dmitrii V. , Trifonov Alexey Yu. , Saraykin Vladimir V. , Lutzau Alexandr V.
Published: October 2013

ZnO nanoparticles (NPs) formed in Czochralski-grown n-type (100) silicon substrates have been studied. The NPs were formed by co-implantation of 64Zn+ and 16O+ ions followed by furnace annealing in neutral/inert atmospheres for 1h. High-resolution transmission electron microscopy (HR TEM) of cross-section samples enabled the structural properties of the near surface layers to be characterized after implantation and annealing. The distribution of implant profiles was analyzed by secondary ion mass-spectrometry (SIMS). The surface morphology was studied by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Identification of the phase content of the materials was carried out by high-resolution X-ray diffraction in θ-2θ scanning mode. In as-implanted samples, a big amorphous layer was formed which destroyed the NPs beneath the surface. After furnace annealing from 600 up to 800°C, ZnO(102) NPs with a size of ~7nm were formed in the recrystallization layer. Furnace annealing at temperatures above 900 °C gave rise to a restructuring of the silicon surface and ZnO NPs formed on the sample surface. At temperatures above 1000 °C, out-diffusion of Zn from the sample occurred due to the large diffusion coefficient Zn at these temperatures.
Primary Monophasic Synovial Sarcoma of the Kidney: A Case Report and Review of Literature
Authors: Lopes Henrique , Pereira Caio A.D. , Zucca Luís E.R. , Serrano Sérgio V. , Silva Sandra R.M. , Camparoto Marjori L. , Cárcano Flavio M.
Published: October 2013

Primary synovial sarcoma (SS) of the kidney is a rare neoplasm and its presenting features are similar to other common renal tumors, making early diagnosis difficult. To date, few cases have been reported in the literature. Primary renal SSs can exist in either a monophasic or a biphasic pattern, the former being more common and tending to have a better prognosis than the biphasic variant. Herein we describe a case of primary renal SS that was diagnosed based on histopathology and immunohistochemistry after radical nephrectomy. Fusion gene product analysis was also done by FISH and RT-PCR. Patient follow-up and literature review are presented, focused on systemic therapy. We highlight that these tumors should be correctly diagnosed as clinical results and specific treatment are distinct from primary epithelial renal cell carcinoma. Adjuvant chemotherapy should be tailored for each patient in the management of disease, although its role still remains unclear.
Expression d'un facteur epsilon de paire par une formule intégrale
Authors: Beuzart-Plessis Raphaël
Published: October 2013

Let E/F be a quadratic extension of p–adic fields and let d, m be nonnegative integers of distinct parities. Fix admissible irreducible tempered representations π and σ of GLd(E) and GLm(E) respectively. We assume that π and σ are conjugate–dual. That is to say
and where c is the nontrivial F–automorphism of E. This implies that we can extend π to an unitary representation π of a nonconnected group GLd(E) . Define the same way. We state and prove an integral formula for involving the characters of and . ˜˜This formula is related to the local Gan–Gross–Prasad conjecture for unitary groups.
Chronic inflammation of the joints – the transition from pediatric rheumatologist to adult rheumatologist. Recommendations of the Panel of Experts on National Consultant in the field of rheumatology (recommendations in the context of the conditions relating to compliance)
Authors: Rutkowska-Sak Lidia , Majdan Maria , Tłustochowicz Małgorzata , Tłustochowicz Witold
Published: October 2013

Młodzieńcze idiopatyczne zapalenie stawów (MIZS) ma kilka postaci klinicznych. U kilkudziesięciu procent chorych na MIZS po osiągnięciu dorosłości utrzymuje się znacząca aktywność choroby, niezależnie od niskorosłości, niepełnosprawności ruchowej, osteoporozy, dysfunkcji narządów wewnętrznych i narządu wzroku. Niekiedy powikłaniem choroby jest skrobiawica. Poszczególne postaci MIZS często przybierają w wieku dorosłym obraz kliniczny swoich odpowiedników – przewlekłych zapaleń stawów sklasyfikowanych u osób dorosłych. Część postaci niezróżnicowanych nadal pozostaje postacią niezróżnicowaną. Odrębny obraz kliniczny przez cały okres choroby u dzieci i u dorosłych najczęściej ma postać MIZS nielicznostawowa przetrwała z obecnością przeciwciał przeciwjądrowych z zapaleniem błony naczyniowej oka lub bez niego.

U dorosłych liczba leków zarejestrowanych do leczenia przewlekłych zapaleń stawów jest większa niż u dzieci. Ścisłe odgraniczenie w zapisach programów lekowych dla MIZS i dla zapaleń stawów u dorosłych utrudnia kontynuację leczenia po osiągnięciu wieku dojrzałego.
Osteoporosis fracture of sacral bone treated with bone cement – sacroplasty
Authors: Gasik Robert , Kamińska-Tchórzewska Ewa
Published: October 2013

W artykule przedstawiono przypadek chorej, u której złamanie kości krzyżowej prowokowało ból uniemożliwiający wykonywanie podstawowych codziennych czynności. Z tego powodu chora była leczona zachowawczo ambulatoryjnie, a następnie hospitalizowana. Stosowane u pacjentki leczenie farmakologiczne bólu, zgodnie z zaleceniami przedstawionymi w schemacie drabiny analgetycznej Światowej Organizacji Zdrowia, nie przyniosło efektów terapeutycznych. W związku z utrzymującym się bólem zaproponowano leczenie chirurgiczne. Choroby współistniejące uniemożliwiały przeprowadzenie zabiegu w znieczuleniu ogólnym. U chorej wykonano zabieg stabilizacji z użyciem cementu kostnego (sakroplastykę), stosując jedynie leki nasenne i przeciwbólowe. W wyniku zabiegu dolegliwości bólowe zmniejszyły się o ponad 70%, zwiększyła się również aktywność ruchowa pacjentki.
Tropical tropopause ice clouds: a dynamic approach to the mystery of low crystal numbers
Authors: Spichtinger P. , Krämer M.
Published: October 2013

Abstract. The occurrence of high, persistent ice supersaturation inside and outside cold cirrus in the tropical tropopause layer (TTL) remains an enigma that is intensely debated as the "ice supersaturation puzzle". However, it was recently confirmed that observed supersaturations are consistent with very low ice crystal concentrations, which is incompatible with the idea that homogeneous freezing is the major method of ice formation in the TTL. Thus, the tropical tropopause "ice supersaturation puzzle" has become an "ice nucleation puzzle". To explain the low ice crystal concentrations, a number of mainly heterogeneous freezing methods have been proposed. Here, we reproduce in situ measurements of frequencies of occurrence of ice crystal concentrations by extensive model simulations, driven by the special dynamic conditions in the TTL, namely the superposition of slow large-scale updraughts with high-frequency short waves. From the simulations, it follows that the full range of observed ice crystal concentrations can be explained when the model results are composed from scenarios with consecutive heterogeneous and homogeneous ice formation and scenarios with pure homogeneous ice formation occurring in very slow (< 1 cm s−1) and faster (> 1 cm s−1) large-scale updraughts, respectively. This statistical analysis shows that about 80% of TTL cirrus can be explained by "classical" homogeneous ice nucleation, while the remaining 20% stem from heterogeneous and homogeneous freezing occurring within the same environment. The mechanism limiting ice crystal production via homogeneous freezing in an environment full of gravity waves is the shortness of the gravity waves, which stalls freezing events before a higher ice crystal concentration can be formed.
Kinetic measurements on the reactivity of hydrogen peroxide and ozone towards small atmospherically relevant aldehydes, ketones and organic acids in aqueous solution
Authors: Schöne L. , Herrmann H.
Published: October 2013

Abstract. Within the aqueous atmospheric environment free radical reactions are an important degradation process for organic compounds. Nevertheless, non-radical oxidants like hydrogen peroxide and ozone also contribute to the degradation and conversion of this substance group (Tilgner und Herrmann, 2010). In this work kinetic investigations of non-radical reactions were conducted using UV/Vis spectroscopy (dual-beam spectrophotometer and Stopped Flow technique) and a capillary electrophoresis system applying pseudo-first order kinetics of glyoxal, methylglyoxal, glycolaldehyde, glyoxylic, pyruvic and glycolic acids as well as methacrolein (MACR) and methyl vinyl ketone (MVK) towards H2O2 and ozone. The measurements indicate rather small rate constants at room temperature of k2nd < 3 M−1 s−1 (except for the unsaturated compounds exposed to ozone). Compared to radical reaction rate constants the values are about 10 orders of magnitude smaller (kOH· ~ 109 M−1 s−1). However, when considering the much larger non-radical oxidant concentrations compared to radical concentrations in urban cloud droplets, calculated turnovers change the picture to more important H2O2 reactions especially when compared to the nitrate radical. For some reactions also mechanistic suggestions are given.
New retrieval of BrO from SCIAMACHY limb: an estimate of the stratospheric bromine loading during April 2008
Authors: Parrella J. P. , Chance K. , Salawitch R. J. , Canty T. , Dorf M. , Pfeilsticker K.
Published: October 2013

Abstract. We present a new retrieval of stratospheric BrO (bromine monoxide) from channel 2 SCIAMACHY (SCanning Imaging Absorption spectrometer for Atmospheric CHartographY) limb observations. Retrievals are shown to agree with independent balloon observations to within one standard deviation of the retrieval noise. We retrieve BrO profiles for all of April 2008, and apply simulated [BrO]/[Bry] (bromine monoxide : stratospheric inorganic bromine) ratios to estimate the stratospheric Bry loading. We find 23.5 ± 6 ppt Br, suggesting 7 ppt Br from short-lived bromocarbons to be at the high end of the current best estimate (3–8 ppt). The 6 ppt Br uncertainty estimate is dominated by the 21% uncertainty in the simulated [BrO] / [Bry] ratio due to propagation of errors from the underlying chemical kinetics.
Near-infrared remote sensing of Los Angeles trace gas distributions from a mountaintop site
Authors: Fu D. , Pongetti T. J. , Blavier J.-F. L. , Crawford T. J. , Manatt K. S. , Toon G. C. , Wong K. W. , Sander S. P.
Published: October 2013

Abstract. The Los Angeles basin is a significant anthropogenic source of major greenhouse gases (CO2 and CH4) and the pollutant CO, contributing significantly to regional and global climate change. We present a novel approach for monitoring the spatial and temporal distributions of greenhouse gases in the Los Angeles basin using a high-resolution spectroscopic remote sensing technique. A new Fourier Transform Spectrometer called CLARS-FTS has been deployed since May 2010 at JPL's California Laboratory for Atmospheric Remote Sensing (CLARS) on Mt. Wilson, California for automated long-term measurements of greenhouse gases. The instrument design and performance of CLARS-FTS are presented. From its mountaintop location at an altitude of 1673 m, the instrument points at a programmed sequence of ground target locations in the Los Angeles basin, recording spectra of reflected near-IR solar radiation. Column-averaged dry-air mole fractions of greenhouse gases (XGHG) including XCO2, XCH4, and XCO are retrieved several times per day for each target. Spectra from a local Spectralon® scattering plate are also recorded to determine background (free tropospheric) column abundances above the site. Comparisons between measurements from LA basin targets and the Spectralon® plate provide estimates of the boundary layer partial column abundances of the measured species. Algorithms are described for transforming the measured interferograms into spectra, and for deriving column abundances from the spectra along with estimates of the measurement precision and accuracy. The CLARS GHG measurements provide a means to infer relative, and possibly absolute, GHG emissions.
The CRUTEM4 land-surface air temperature dataset: construction, previous versions and dissemination via Google Earth
Authors: Osborn T. J. , Jones P. D.
Published: October 2013

Abstract. The CRUTEM4 (Climatic Research Unit Temperature version 4) land-surface air temperature dataset is one of the most widely used records of the climate system. Here we provide an important additional dissemination route for this dataset: online access to monthly, seasonal and annual data values and timeseries graphs via Google Earth. This is achieved via an interface written in Keyhole Markup Language (KML) and also provides access to the underlying weather station data used to construct the CRUTEM4 dataset. A mathematical description of the construction of the CRUTEM4 dataset (and its predecessor versions) is also provided, together with an archive of some previous versions and a recommendation for identifying the precise version of the dataset used in a particular study. The CRUTEM4 dataset used here is available from doi:10.5285/EECBA94F-62F9-4B7C-88D3-482F2C93C468.
Validation of the operational MSG-SEVIRI snow cover product over Austria
Authors: Surer S. , Parajka J. , Akyurek Z.
Published: October 2013

Abstract. The objective of this study is to evaluate the mapping accuracy of the MSG-SEVIRI operational snow cover product over Austria. The SEVIRI instrument is on board of the geostationary Meteosat Second Generation (MSG) satellite. The snow cover product provides 32 images per day with a relatively low spatial resolution of 5 km over Austria. The mapping accuracy is examined at 178 stations with daily snow depth observations and compared with the daily MODIS combined (Terra + Aqua) snow cover product in the period April 2008–June 2012. The results show that the 15 min temporal sampling allows a significant reduction of clouds in the snow cover product. The mean annual cloud coverage is less than 30% in Austria, as compared to 52% for the combined MODIS product. The mapping accuracy for cloud-free days is 89% as compared to 94% for MODIS. The largest mapping errors are found in regions with large topographical variability. The errors are noticeably larger at stations with elevations that differ much from those of the mean MSG-SEVIRI pixel elevations. The median of mapping accuracy for stations with absolute elevation difference less than 50 m and more than 500 m is 98.9% and 78.2%, respectively. A comparison between the MSG-SEVIRI and MODIS products indicates an 83% overall agreement. The largest disagreements are found in alpine valleys and flatland areas in the spring and winter months, respectively.
Assessment of pulmonary toxicity of MgO nanoparticles in rats
Authors: Gelli Kiranmai , Porika Mahendar , Anreddy Rama Narsimha Reddy
Published: October 2013

In this study, we have evaluated the pulmonary toxicity of MgO nanoparticles (MgO NPs) in rats following their exposure. NPs in phosphate buffered saline + 1% Tween 80 were exposed via intratracheal instillation at a doses of 1 mg/kg or 5 mg/kg into rat lungs and evaluated for various tissue damage markers like alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid and histopathology of lungs at 1, 7, and 30 days of post‐exposure intervals. A dose‐dependant increase in ALP and LDH activity was observed in BAL fluids of rat lungs than sham control at all post‐exposure periods (P <0.05), and a dose‐dependant infiltration of interstitial lymphocytes, peribronchiolar lymphocytic infiltration, and dilated and/or congested vessels at 1 day post‐exposure period, worsened at 1 week period, and were reduced at 1 month at histology, indicating the pulmonary toxicity of MgO NPs. In conclusion, MgO NPs exposure produced a dose‐dependent pulmonary toxicity in rats and was comparable with that of Quartz particles. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 308–314, 2015.