bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical Prediction of Physicochemical Properties, Performances and Sensitivities of some New Derivatives of Dinitro Triazolyl Triazine
Authors: Keshavarz Mohammad Hossein , Esmailpoor Karim , Tehrani Masoud Kavosh 
Published: June 2010

AbstractIn this paper, important properties of some new derivatives of dinitro triazolyl triazine as novel heterocyclic energetic compounds are evaluated and discussed by using some reliable models. The predicted properties are also compared with octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) as a benchmark compound and 2,4,6‐trinitro‐1,3,5‐triazine (TNTA) as a theoretically new high performance energetic compound. It is shown that some of these compounds can be seen as interesting high‐nitrogen organic explosives with relatively low sensitivity which could be introduced for some important industrial applications. Since some of the new compounds have good oxygen balance, calculated specific impulses confirm that these compounds can be considered as suitable oxidizers in solid propellants.
Molecular orientation studied by reflection anisotropy spectroscopy
Authors: Lane P. D. , Isted G. E. , Cole R. J. 
Published: June 2010

AbstractA description of the reflection anisotropy spectroscopy (RAS) results from oriented thin films is presented. The RAS signals of a 1 nm thick film are simulated to investigate the effect of molecular tilt on the RAS response of the system. Whilst the spectroscopic measurements themselves appear to be relatively insensitive to the effects of the tilt, the variation of the RAS signal with rotation of the sample azimuthal angle sees sensitivity to out of surface plane anisotropy, characterized by a sin θs effect.
Nonradiative resonance energy transfer directed from colloidal CdSe/ZnS quantum dots to epitaxial InGaN/GaN quantum wells for solar cells
Authors: Nizamoglu Sedat , Sari Emre , Baek Jong‐Hyeob , Lee In‐Hwan , Demir Hilmi Volkan 
Published: June 2010

AbstractWe report on Förster‐type nonradiative resonance energy transfer (NRET) directed from colloidal quantum dots (QDs) to epitaxial quantum wells (QWs) with an efficiency of 69.6% at a rate of 1.527 ns–1 for potential application in III‐nitride based photovoltaics. This hybrid exciton generation–collection system consists of chemically‐synthesized cyan CdSe/ZnS core/shell QDs (λPL = 490 nm) intimately integrated on epitaxially‐grown green InGaN/GaN QWs (λPL = 512 nm). To demonstrate directional NRET from donor QDs to acceptor QWs, we simultaneously show the decreased photoluminescence decay lifetime of dots and increased lifetime of wells in the hybrid dipole–dipole coupled system. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The development of artemisinin resistance in malaria: reasons and solutions
Authors: Chrubasik Cosima , Jacobson Raymond L. 
Published: June 2010

AbstractDespite world‐wide efforts in fighting malaria, this mosquito‐borne infectious disease is a huge burden for the population, especially in tropical and subtropical areas. The WHO recommends artemisinin‐based combination therapy for the treatment of uncomplicated Plasmodium falciparum malaria. However, artemisinin resistance cannot now be ignored. Factors affecting the development of artemisinin resistance include uncontrolled use of artemisinin‐based combination therapy (ACT), mobile populations and migrants, artemisinin monotherapy, the use of subtherapeutic levels of artesiminin, substandard and counterfeit drugs, high treatment cost, and co‐use of artemisinin derivates as prophylactic agents. Promising herbal alternatives are already in the pipeline, but the only long‐term solution for eradicating malaria would be the development of a successful vaccination. Copyright © 2010 John Wiley & Sons, Ltd.
Antiinflammatory activity of coumarins from Ligusticum lucidum Mill. subsp. cuneifolium (Guss.) Tammaro (Apiaceae)
Authors: Menghini Luigi , Epifano Francesco , Genovese Salvatore , Marcotullio Maria C. , Sosa Silvio , Tubaro Aurelia 
Published: June 2010

AbstractFour coumarin derivatives [selidinin 1, (+)‐praeruptorin A 2, visnadin 3 and (R)‐(+)‐7‐(2′,3′‐epoxy‐3′‐methylbutoxy)‐coumarin 4] were isolated from the aerial parts of Ligusticum lucidum Mill. subsp. cuneifolium (Guss.) Tammaro (Apiaceae). This is the first report on the identification of these compounds in the Ligusticum genus. Their topical antiinflammatory activity was evaluated as the inhibition of croton oil‐induced ear dermatitis in mice. Each compound (0.3 μmol/cm2) induced a significant oedema reduction and compound 4 exerted an effect similar to that of the equimolar dose of the reference drug indomethacin. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of damming a large lowland river on chironomids and fish assessed with the (multiplicative partitioning of) true/Hill biodiversity measure
Authors: Głowacki Ł. , Grzybkowska M. , Dukowska M. , Penczak T. 
Published: June 2010

AbstractThe impact of a large lowland temperate zone reservoir on chironomid and fish biodiversity was investigated in the same upstream (U) and downstream (D) sites on the same sampling occasions in spring and autumn of several post‐impoundment years. The true/Hill N1 diversity measure was used to construct diversity models of the impact, and partitioning of N1 to reveal the importance of ecological gradients. N1 is unique in being decomposable among multiple levels and easily comparable across ecosystems and animal groups.Chironomids were more diverse than fish in all community sets owing to their probably lower mobility, lower interspecific competition, opportunistic character and much shorter life spans than those of fish. Fish exerted consumption pressure on chironomids upstream by foraging mostly on benthic insects, but not downstream where they fed on microcrustaceans of reservoir origin or on epiphytic fauna (mainly Chironomidae).The reservoir impact on chironomids decreased their diversity in U and increased in D, while much the opposite was true in fish. In D in macroinvertebrates, the impact consisted in advancing over time intensification of seasonal development of submersed macrophytes, while in D in fish in a few species escaping from the reservoir after their populational explosions each year.Partitioning of diversity revealed that the spatial (upstream–downstream) gradient was the strongest factor of diversity change in chironomids as compared with season, and age of the impoundment. No gradient was dominant in fish. Comparisons of observed data with a null model testified to very strong intraspecific aggregation in both chironomids and fish. Copyright © 2010 John Wiley & Sons, Ltd.
Versatile two‐state land mobile satellite channel model with first application to DVB‐SH analysis
Authors: Prieto‐Cerdeira R. , Perez‐Fontan F. , Burzigotti P. , Bolea‐Alamañac A. , Sanchez‐Lago I. 
Published: June 2010

AbstractStandardization activities on Digital Video Broadcasting–Satellite services to Handheld Devices (DVB‐SH) have driven the need for a consolidated Land Mobile Satellite (LMS) narrowband channel model. In the DVB‐SH system, the satellite broadcasts a signal carrying multimedia services aimed directly to a variety of mobile (handheld or vehicular) and fixed terminals.A three‐state LMS channel model that describes the narrowband propagation channel in three possible shadowing states—line‐of‐sight conditions, moderate shadowing and deep shadowing—had been selected as a baseline for physical layer simulation of the DVB‐SH waveform. This type of model, capable of generating complex time series, was originally selected, because it is the simplest model that allows the simulation of first‐ and second‐order effects of the LMS channel in a realistic manner. The main limitations of such model are, first of all, that a classification in three states does not necessarily correspond with reality and, secondly, that the statistical parameters for each state were fixed for a given scenario and elevation angle. Those limitations may impact the selection of Physical Layer parameters of the DVB‐SH standard.A new channel model is proposed based on the original three‐state model including two major modifications: a reduction in the number of states and the introduction of a versatile selection of statistical parameters describing each state. Furthermore, the state machine is governed either by Markov or by semi‐Markov chains. The new‐state classification does not necessarily correspond to intuitive physical definitions of the states as before (line‐of‐sight, shadowing) but instead to channel variations that share similar statistical characteristics. The two‐states are termed for convenience,GoodandBadstates, representing a range of LOS‐to‐moderate shadowing and moderate‐to‐deep shadowing, respectively. For the model parameters selection, datasets at L‐ and S‐band have been analysed using an iterative algorithm that includes automatic data classification and parameter extraction. The proposed model is considered more suitable for the analysis of DVB‐SH test cases.This study starts with an overview of the main DVB‐SH system parameters and assumptions. The original three‐state model is briefly introduced; the new model is presented in detail, including simulator implementation. Finally, both models and experimental data sets are compared on a statistical basis. The performance of both models are discussed to show how effective the model is for the representation of shadowed conditions and therefore, its suitability for the analysis and optimal configuration of the physical and link layer parameters (namely physical layer interleaver size, link layer protection time, overall redundancy, etc.). Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis of polypyrrole coatings on surface of iron particles
Authors: Oriňáková Renáta , Kupková Miriam , Oriňák Andrej , Fedorková Andrea , Dudrová Eva 
Published: June 2010

AbstractA simple oxidative polymerization of pyrrole (Py) directly onto the surface of Fe microparticles was applied to enhance its mechanical properties and to increase the content of carbon in resulting material. The study is focused on investigation of the chemical synthesis of polypyrrole (PPy) coatings on the surface of iron particles, and their effect on the internal and surface structure. Moreover, the effect of PPy coating on the compressibility of coated Fe powder is analyzed. Namely, a set of specimens was uniaxially pressed in a steel die. Compaction pressures ranged from 100 up to 600 MPa. To quantify the compressibility of powders, the compressibility equation proposed by Panelli and Ambrosio Filho has been. It was found that PPy coating has a positive effect on the compaction behavior of iron powders.Detection and quantification of the PPy coatings obtained were performed by means of pyrolysis gas chromatography (Py‐GC). Both the light optical and scanning electron microscopy (LOM, SEM) were used to characterize the morphology and surface appearance of samples coated with PPy. It was found that the content of PPy in final powder material can be controlled by conditions of chemical oxidative polymerization process. The surface morphology of powder particles coated with PPy layers was changed in compliance with PPy content. Copyright © 2010 John Wiley & Sons, Ltd.
Ion, sputter and useful ion yields for accurate quantification of Si1−xGex(0 < x < 1) using ultra low energy O2+ SIMS
Authors: Morris R. J. H. , Dowsett M. G. 
Published: June 2010

AbstractIt has been previously demonstrated that accurate measurement of x in the Si1−xGex (x ≤ 0.3) alloy can be achieved using a variety of O2+ SIMS conditions. With SiGe device technology still developing to exploit its full potential, the useful matrices now extend from 0 ≤ x ≤ 1. Using the previously established conditions, we have found that roughening of the material occurs when x approaches 1. To overcome this limitation we have developed a set of conditions that enables the whole Si1−xGex (0 ≤ x ≤ 1) range to be quantified. This is achieved by using an O2+ primary beam energy of ≤ 500 eV at near‐normal incidence. Here, we present a comprehensive study of the measured (Si and Ge) ion, useful ion and sputter yield behavior as a function of matrix composition and incident beam energy (250 eV–1 keV), from which these new conditions have been established. For the extended Si1−xGex (0 ≤ x ≤ 1) range and primary beam energies used here, the measured Si and Ge ion yields were found to be well described by quartic, cubic or quadratic dependences as a function of x. The useful ion yields and sputter yields all showed moderate matrix effects, with the former decreasing monotonically for increasing x except in the case of Ge at 250 eV. Here, the useful Ge ion yield was found to be invariant with x while its measured ion yield (for all x) was observed to be proportional to its sputter yield. Copyright © 2010 John Wiley & Sons, Ltd.
New neutral cesium evaporation chamber and UHV suitcase
Authors: Bendler B. , Barrahma R. , Philipp P. , Wirtz T. 
Published: June 2010

AbstractIt is well known that the use of Cs+ primary ions results in an important increase of the negative ionization probability during SIMS analyses. Moreover, Cs+ bombardment allows working in the MCsx+ mode, which is a widely used technique to reduce the matrix effect. A major drawback of Cs+ primary ion bombardment is that the Cs+ beam serves both for the incorporation of Cs and for the sputtering of the surface. Therefore, the sputtering yield, and consequently the cesium surface concentration, are constricted by the primary bombardment conditions.To overcome this problem, the Cation Mass Spectrometer (CMS), equipped with an evaporator delivering a collimated and adjustable stream of neutral Cs onto the sample, has been developed at the SAM department. By continuous Cs0 deposition during the SIMS analysis, optimal Cs surface concentrations, and thus optimal ionization probabilities are obtained.1In order to make the Cs0 deposition technique available for other analysis instruments, a standalone UHV instrument for Cs evaporation prior to SIMS analyses has been developed. Furthermore, a suitcase for the transfer under UHV conditions of the samples in‐between the Cs0 evaporation chamber and the analysis instruments has been designed, to avoid any contaminations. In this work, we present this new Cs0 evaporation chamber, as well as our new UHV suitcase in terms of their characteristics and handling. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis and fragmentation of organic samples by (low‐energy) dynamic SIMS
Authors: Ngo K. Q. , Philipp P. , Jin Y. , Morris S. E. , Shtein M. , Kieffer J. , Wirtz T. 
Published: June 2010

AbstractUp to now, the analysis of organic or biological samples was mainly investigated using static SIMS, while dynamic SIMS was generally limited to the analysis of inorganic samples. The increasing sophistication of organic optoelectronic devices (e.g. organic light emitting diodes and organic photovoltaic cells, etc.) requires molecular‐level dimensional control in the fabrication of multilayered structures with specifically engineered interfaces. However, analytical tools for monitoring such fabrication precision are scarce. In a current project, we address this challenge by advancing the development of low‐energy Secondary Ion Mass Spectrometry (LE‐SIMS) for the analysis of organic‐based optoelectronic materials systems.In the present work, we investigate the fragmentation as well as the ionization mechanisms for several molecules used in such devices: fullerene, copper phthalocyanine and tris(8‐hydroxyquinolinato) aluminium have been deposited onto silicon wafers. The study has been carried out on a Cameca SC‐Ultra instrument under Cs+ bombardment for various impact energies in the M− mode. Constant M− secondary ion intensities have been observed throughout the organic layers for some characteristic fragments of the organic molecules. Copyright © 2010 John Wiley & Sons, Ltd.
Quantitative depth profiling of SiGe‐multilayers with the Atom Probe
Authors: Koelling Sebastian , Gilbert Matthieu , Goossens Jozefien , Hikavyy Andriy , Richard Olivier , Vandervorst Wilfried 
Published: June 2010

AbstractThe laser‐assisted Atom Probe has been proposed as a metrology tool for semiconductor technology to meet the requirements accompanying the analysis of the ever smaller and more complex structures targeted for fabrication. In order to support its routine application, we carried out a quantitative assessment of the performance of the Atom Probe (AP) on semiconductor compound multilayers. We analyzed a silicon, silicon‐germanium multilayer structure with Atom Probe Tomography (APT), SIMS, Transmission Electron Microscopy (TEM) and high resolution X‐ray diffraction (HRXRD), and studied the impact of the laser power on the accuracy. Under optimized conditions, the AP outperforms SIMS by a factor of 3 in terms of depth resolution providing a decay length of less than 0.4–0.6 nm/dec whereas the compositions and layer thicknesses are in close agreement with the SIMS, HRXRD and TEM results. Copyright © 2010 John Wiley & Sons, Ltd.
Absolutely determined inelastic mean free paths for 300–3000 eV electrons in 10 elemental solids
Authors: Nagatomi T. , Tanuma S. , Goto K. 
Published: June 2010

AbstractThe inelastic mean free path (IMFP), surface excitation parameter (SEP), and differential SEP (DSEP) were determined for 10 elemental solids by the absolute analysis of reflection electron energy loss spectra (REELS). The obtained IMFPs were compared with values calculated using predictive equations for the IMFP, and it is found that the obtained IMFPs show a fairly good agreement with those calculated by the TPP‐2M predictive equation. The obtained IMFPs were analyzed by the Fano plot and fitted to the Bethe equation, revealing that the obtained IMFPs are well described by the Bethe equation. The obtained DSEPs were compared with the theoretically calculated DSEPs, and the reasonable agreement between the present and theoretical DSEPs was confirmed. The dependence of the present SEPs on the electron energy is found to be described well by predictive equations for the SEP, and material parameters in the predictive equations were determined. Copyright © 2010 John Wiley & Sons, Ltd.
Growth of thin epitaxial alumina films onto Ni(111): an electron spectroscopy and diffraction study
Authors: Nemsak Slavomir , Skala Tomas , Yoshitake Michiko , Tsud Nataliya , Kim Taeyoung , Yagyu Shinjiro , Matolin Vladimir 
Published: June 2010

AbstractAn epitaxial ultra‐thin alumina layer was prepared on Ni(111) by simultaneous Al deposition and oxidation at elevated temperatures. Different deposition procedures lead to creation of oxide layers of various thicknesses and quality. Low‐energy electron diffraction revealed epitaxial parameters of the films and the relationship between the nickel substrate and the oxide overlayer. Core‐level photoelectron spectroscopy using Al‐Kα and synchrotron‐generated photons show that the oxide‐metal interface is formed by oxygen atoms, which is contrary to the case of epitaxial alumina layers prepared by the oxidation of NiAl(110) and Ni3Al(111) surfaces. The results of a photoelectric work function measurement are also discussed. Copyright © 2010 John Wiley & Sons, Ltd.
The characterization of the interfacial interaction between polymeric methylene diphenyl diisocyanate and aluminum: a ToF‐SIMS and XPS study
Authors: Shimizu Kyoko , Phanopoulos Christopher , Loenders Raf , Abel Marie‐Laure , Watts John F. 
Published: June 2010

AbstractTime of flight secondary ion mass spectrometry (ToF‐SIMS) and X‐ray photoelectron spectroscopy (XPS) have been employed to study the interfacial interaction between polymeric methylene diphenyl diisocyanate (PMDI) and aluminum produced by the deposition of a thin PMDI layer on the aluminum, in order to improve adhesion and/or abhesion performance.When the PMDI concentration increases, the intensity ratio fragments indicative of the reaction product with water (m/z = 106 u: C7H8N+) to that of isocyanate group (m/z = 132 u: C8H6NO+) decreases. A very thin MDI layer on oxidized aluminum samples exhibits lower 106/132 ratio than degreased samples as a result of less hydroxide/hydroxyl species on the surface. This suggests that water reactions occur both at the surface of PMDI and at the PMDI/aluminum interface. The variation of the PMDI chemistry has also been studied by exposing PMDI treated samples to the air for various periods of time (a few hours to 14 days), in order to assess the reaction of the PMDI surface and PMDI/aluminum interface. At the interface, the yield of reaction with water is limited because of the finite amount of hydroxyl groups on the aluminum surface, and the water reaction is completed in a short period of time. However, the PMDI surface continues to react with water from the atmospheric. This methodology was also used to establish the presence of specific interactions at the PMDI/aluminum interface, and a fragment indicative of covalent bond formation between PMDI and aluminum (AlCHNO3−) is observed at the interface. Copyright © 2010 John Wiley & Sons, Ltd.
Porcelain tile surface modification with isocyanate coupling agent: interactions between EVA modified mortar and silane improving adherence
Authors: Mansur A. A. P. , Nascimento O. L. do , Oréfice R. L. , Mansur H. S. 
Published: June 2010

AbstractAdhesion between tiles and mortar is of paramount importance to the overall stability of ceramic tile systems. The interfaces between ceramic tiles and polymer‐modified Portland cement mortar are derived from several physical and chemical phenomena that take place during their formation. From the chemical perspective, weak forces are expected to occur preferably at the tiles and polymer‐modified Portland cement mortar interfaces. Therefore, the purpose of this study was to promote a new chemical functionalization of ceramic tile surfaces by modifying with isocyanate‐trialkoxysilane coupling agent in order to enhance the interfacial adhesion with poly (ethylene‐co‐vinyl acetate), EVA, polymer‐modified mortar. Pull‐off tests and Fourier Transformed Infrared Spectroscopy (FTIR), using the Attenuated Total Reflectance method, were carried out in order to characterize the system. The bond strength results have provided evidence toward improvements in adherence at the tile–polymer modified mortar interface, thus reflecting the development of urethane linkages between silane and EVA polymer, as detected by FTIR. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis of the noise properties of a solid‐state SCAPS ion imager and development of software noise reduction
Authors: Yamamoto K. , Sakamoto N. , Yurimoto H. 
Published: June 2010

AbstractBy analyzing the noise characteristics of a stacked CMOS‐type active pixel sensor (SCAPS), we developed a noise reduction method. We also developed a multiple frame‐averaging method based on a correlated double sampling (CDS) between averaged frames, which use the multiple frames collected by nondestructive readout of signals before and after ion irradiation. This method suppresses SCAPS read noise to 11 µV, corresponding to 0.37 ions. Ion transfer and noise performance were evaluated by above method, leading to the confirmation of noise suppression below the level of single ion detection and the expansion of the dynamic range of SCAPS to 102 dB. Copyright © 2010 John Wiley & Sons, Ltd.