bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vacuum Ultraviolet Annealing of Tantalum Oxide Films Deposited at Room Temperature by Photo-Induced Cvd
Authors: Zhang J.-Y. , Boyd I.W. 
Published: April 2011

ABSTRACTIn this paper, we report the effect of vacuum ultraviolet (VUV) annealing of tantalum oxide films deposited on Si (100) and quartz at room temperature by photo-induced chemical vapour deposition using excimer lamps. The influences of annealing pressure and temperature on the structural and optical properties have been studied using ellipsometry, Fourier transform infrared spectroscopy (FTIR) and UV spectrophotometry. Under optimum annealing conditions, the refractive index of the films was found to be around 2.15, while a dielectric constant of 24, a breakdown field of 2.3 MV/cm and an optical transmittance in the visible region of the spectrum greater than 85% were obtained.
Electronic States of Self-Assembled Quantum Dots: Symmetries in a Quantum Lens
Authors: Rodríguez Arezky H. , Trallero-Giner C. , Marín-Antuña J. , Ulloa S. E. 
Published: April 2011

ABSTRACTElectronic states in self-assembled quantum dots with a lens geometry are studied. A conformal analytical map is used to transform the quantum dot boundary into a dot with semi-spherical shape. The Hamiltonian for a carrier confined in the quantum lens is also mapped into an equivalent operator and its eigenvalues and eigenfunctions for the corresponding Dirichlet problem, of confinement by infinite walls, are analyzed. A modified Rayleigh-Schrddinger perturbation theory is developed to obtain analytical expressions for the energy levels and wavefunctions depending on the height b and radius a of the circular cross section of the spherical cap lens. Numerical calculations are shown for typical cases. The effects of decreasing rotational symmetry on the energy states and eigenfunctions of the quantum dot with lens-shape are presented: The degeneracy due to the z-component of the angular momentum m is broken for b ∦ a. Energy states and wavefunctions with m = 0 present the most pronounced influence on the b ∦ a case. Analytical expressions presented here can be used to estimate the sizes of actual self-assembled quantum dots.
Growth and Characterization of Gan Bulk Crystals Via Vapor Phase Transport
Authors: Shin H. , Thomson D. B. , Miraglia P. Q. , Wolter S. D. , Schlesser R. , Sitar Z. , Davis R. F. 
Published: April 2011

ABSTRACTFree-standing single crystals of bulk GaN were grown via unseeded vapor phase transport at 1130°C on hexagonal BN surfaces via direct reaction of Ga with ammonia. The number of nucleation events was reduced and the crystal size increased by introducing the ammonia at high temperatures. The resulting crystals were either needles or platelets depending on the process variables employed. Low V/III ratios achieved via ammonia flow rates ≤ 75sccm and/or ammonia total pressures ≤ 430Torr favored lateral growth. The average lateral growth rate for the platelets was ∼50μm/hr; the average vertical growth rate for the needles was ∼500μm/hr. Growth rates in all other directions for each of these two morphologies were very low. Seeded growth of both needle and platelet crystals was also achieved; however, the growth rate decreased at longer times and higher pressures due to reaction with H2 from the increased decomposition of ammonia. Nitrogen dilution suppressed this decomposition. A 2mm × 1.5mm GaN crystal was grown with minimal decomposition in a 66.7%NH3 and 33.3%N2 gas mixture.
Cathodoluminescence and Micro-Structure of Polycrystalline GaN Grown on ZnO/Si
Authors: Araki Tsutomu , Kagatsume Hidetaka , Aono Hiroaki , Nanishi Yasushi 
Published: April 2011

ABSTRACTWe have investigated relationships between microscopic structure and cathodoluminescence (CL) property of polycrystalline (poly-) GaN grown by electron-cyclotron-resonance plasma-excited molecular beam epitaxy (ECR-MBE) on ZnO/Si substrates. Very strong CL with a peak of 3.45 eV was observed from the poly-GaN, which mainly showed a columnar structure with a size of 50-100 nm. On the other hand, the intensity of CL from the poly-GaN with few columnar domains was weaker than that of the poly-GaN with the columnar structure. The CL image from the poly-GaN, in which the columnar domains were locally observed, showed a strong contrast between bright domains and a dark background. It is confirmed that these bright regions in the CL images are corresponding to the columnar domains of the poly-GaN, by comparing with the SEM images. These results suggest that the columnar domains are responsible for the strong CL from the poly-GaN grown on the ZnO/Si substrates. Cross-sectional transmission electron microscope (TEM) observation revealed that the columnar domains had high quality crystallinity with few defects.
Film Properties of High-Performance FSG Films
Authors: Yoda T. , Miyajima H. , Fujita K. , Nakata R. , Nishiyama Y. 
Published: April 2011

AbstractAn advanced FSG film of k=3.4 was developed, which exhibited excellent resistance for moisture absorption. Physical and chemical properties of this advanced FSG film were compared by typical FSG films deposited in both high density plasma (HDP) and PE-CVD reactors, for the same k value.The advanced FSG film appears to be superior to the HDP-FSG film by a wide margin in the following tests. The moisture absorption rate by TDS (after 4 days of air exposure) is about 5 times lower, the hardness was 1.8 times more, and the hygroscopicity (after 1 hr. boiling) was 2.6 times lower.We conclude that these differences are mainly due to the unique film structure of the advanced FSG film.
Biocompatibility and Bone Formation of Flexible, Cotton Wool-like PLGA/Calcium Phosphate Nanocomposites in Sheep
Authors: Schneider Oliver D , Mohn Dirk , Fuhrer Roland , Klein Karina , Kämpf Käthi , Nuss Katja M.R , Sidler Michèle , Zlinszky Katalin , Rechenberg Brigitte von , Stark Wendelin J 
Published: March 2011

Background:The purpose of this preliminary study was to assess thein vivoperformance of synthetic, cotton wool-like nanocomposites consisting of a biodegradable poly(lactide-co-glycolide) fibrous matrix and containing either calcium phosphate nanoparticles (PLGA/CaP 60:40) or silver doped CaP nanoparticles (PLGA/Ag-CaP 60:40). Besides its extraordinaryin vitrobioactivity the latter biomaterial (0.4 wt% total silver concentration) provides additional antimicrobial properties for treating bone defects exposed to microorganisms.Materials and Methods:Both flexible artificial bone substitutes were implanted into totally 16 epiphyseal and metaphyseal drill hole defects of long bone in sheep and followed for 8 weeks. Histological and histomorphological analyses were conducted to evaluate the biocompatibility and bone formation applying a score system. The influence of silver on thein vivoperformance was further investigated.Results:Semi-quantitative evaluation of histology sections showed for both implant materials an excellent biocompatibility and bone healing with no resorption in the adjacent bone. No signs of inflammation were detectable, either macroscopically or microscopically, as was evident in 5 µm plastic sections by the minimal amount of inflammatory cells. The fibrous biomaterials enabled bone formation directly in the centre of the former defect. The area fraction of new bone formation as determined histomorphometrically after 8 weeks implantation was very similar with 20.5 ± 11.2 % and 22.5 ± 9.2 % for PLGA/CaP and PLGA/Ag-CaP, respectively.Conclusions:The cotton wool-like bone substitute material is easily applicable, biocompatible and might be beneficial in minimal invasive surgery for treating bone defects.
Functional Sympatholysis During Exercise in Patients With Type 2 Diabetes With Intact Response to Acetylcholine
Authors: Thaning Pia , Bune Laurids T. , Zaar Morten , Saltin Bengt , Rosenmeier Jaya B. 
Published: March 2011

OBJECTIVE
Sympathetic vasoconstriction is blunted in contracting human skeletal muscles (functional sympatholysis). In young subjects, infusion of adenosine and ATP increases blood flow, and the latter compound also attenuates α-adrenergic vasoconstriction. In patients with type 2 diabetes and age-matched healthy subjects, we tested 1) the sympatholytic capacity during one-legged exercise, 2) the vasodilatory capacity of adenosine and ATP, and 3) the ability to blunt α-adrenergic vasoconstriction during ATP infusion.

RESEARCH DESIGN AND METHODS
In 10 control subjects and 10 patients with diabetes and normal endothelial function, determined by leg blood flow (LBF) response to acetylcholine infusion, we measured LBF and venous NA, with and without tyramine-induced sympathetic vasoconstriction, during adenosine-, ATP-, and exercise-induced hyperemia.

RESULTS
LBF during acetylcholine did not differ significantly. LBF increased ninefold during exercise and during adenosine- and ATP-induced hyperemia. Infusion of tyramine during exercise did not reduce LBF in either the control or the patient group. During combined ATP and tyramine infusions, LBF decreased by 30% in both groups. Adenosine had no sympatholytic effect.

CONCLUSIONS
In patients with type 2 diabetes and normal endothelial function, functional sympatholysis was intact during moderate exercise. The vasodilatory response for adenosine and ATP did not differ between the patients with diabetes and the control subjects; however, the vasodilatory effect of adenosine and ATP and the sympatholytic effect of ATP seem to decline with age.
FSP and FLTL framework for specification and verification of middle-agents
Authors: Bădică Amelia , Bădică Costin 
Published: March 2011

FSP and FLTL framework for specification and verification of middle-agents
Agents are a useful abstraction frequently employed as a basic building block in modeling service, information and resource sharing in global environments. The connecting of requester with provider agents requires the use of specialized agents known as middle-agents. In this paper, we propose a formal framework intended to precisely characterize types of middle-agents with a special focus on matchmakers, brokers and front-agents by formally modeling their interactions with requesters and providers. Our approach is based on capturing interaction protocols between requesters, providers and middle-agents as finite state processes represented using FSP process algebra. The resulting specifications are formally verifiable using FLTL temporal logic. The main results of this work include (i) precise specification of interaction protocols depending on the type of middle-agent (this can also be a basis for characterizing types of middle-agents), (ii) improvement of communication between designers and developers and facilitation of formal verification of agent systems, (iii) guided design and implementation of agent-based software systems that incorporate middle-agents.
Application of agent-based simulated annealing and tabu search procedures to solving the data reduction problem
Authors: Czarnowski Ireneusz , Jędrzejowicz Piotr 
Published: March 2011

Application of agent-based simulated annealing and tabu search procedures to solving the data reduction problemThe problem considered concerns data reduction for machine learning. Data reduction aims at deciding which features and instances from the training set should be retained for further use during the learning process. Data reduction results in increased capabilities and generalization properties of the learning model and a shorter time of the learning process. It can also help in scaling up to large data sources. The paper proposes an agent-based data reduction approach with the learning process executed by a team of agents (A-Team). Several A-Team architectures with agents executing the simulated annealing and tabu search procedures are proposed and investigated. The paper includes a detailed description of the proposed approach and discusses the results of a validating experiment.
Experimental analysis of some computation rules in a simple parallel reasoning system for the ALC description logic
Authors: Meissner Adam 
Published: March 2011

Experimental analysis of some computation rules in a simple parallel reasoning system for theALCdescription logicA computation rule determines the order of selecting premises during an inference process. In this paper we empirically analyse three particular computation rules in a tableau-based, parallel reasoning system for theALCdescription logic, which is built in the relational programming model in the Oz language. The system is constructed in the lean deduction style, namely, it has the form of a small program containing only basic mechanisms, which assure soundness and completeness of reasoning. In consequence, the system can act as a convenient test-bed for comparing various inference algorithms and their elements. We take advantage of this property and evaluate the studied methods of selecting premises with regard to their efficiency and speedup, which can be obtained by parallel processing.
Algebraic approach for model decomposition: Application to fault detection and isolation in discrete-event systems
Authors: Berdjag Denis , Cocquempot Vincent , Christophe Cyrille , Shumsky Alexey , Zhirabok Alexey 
Published: March 2011

Algebraic approach for model decomposition: Application to fault detection and isolation in discrete-event systemsThis paper presents a constrained decomposition methodology with output injection to obtain decoupled partial models. Measured process outputs and decoupled partial model outputs are used to generate structured residuals for Fault Detection and Isolation (FDI). An algebraic framework is chosen to describe the decomposition method. The constraints of the decomposition ensure that the resulting partial model is decoupled from a given subset of inputs. Set theoretical notions are used to describe the decomposition methodology in the general case. The methodology is then detailed for discrete-event model decomposition using pair algebra concepts, and an extension of the output injection technique is used to relax the conservatism of the decomposition.
Stability of impulsive Hopfield neural networks with Markovian switching and time-varying delays
Authors: Raja Ramachandran , Sakthivel Rathinasamy , Anthoni Selvaraj , Kim Hyunsoo 
Published: March 2011

Stability of impulsive Hopfield neural networks with Markovian switching and time-varying delaysThe paper is concerned with stability analysis for a class of impulsive Hopfield neural networks with Markovian jumping parameters and time-varying delays. The jumping parameters considered here are generated from a continuous-time discrete-state homogenous Markov process. By employing a Lyapunov functional approach, new delay-dependent stochastic stability criteria are obtained in terms of linear matrix inequalities (LMIs). The proposed criteria can be easily checked by using some standard numerical packages such as the Matlab LMI Toolbox. A numerical example is provided to show that the proposed results significantly improve the allowable upper bounds of delays over some results existing in the literature.
Simple environment for developing methods of controlling chaos in spatially distributed systems
Authors: Korus Łukasz 
Published: March 2011

Simple environment for developing methods of controlling chaos in spatially distributed systemsThe paper presents a simple mathematical model called a coupled map lattice (CML). For some range of its parameters, this model generates complex, spatiotemporal behavior which seems to be chaotic. The main purpose of the paper is to provide results of stability analysis and compare them with those obtained from numerical simulation. The indirect Lyapunov method and Lyapunov exponents are used to examine the dependence on initial conditions. The net direction phase is introduced to measure the symmetry of the system state trajectory. In addition, a real system, which can be modeled by the CML, is presented. In general, this article describes basic elements of environment, which can be used for creating and examining methods of chaos controlling in systems with spatiotemporal dynamics.
Hierarchical residue number systems with small moduli and simple converters
Authors: Tomczak Tadeusz 
Published: March 2011

Hierarchical residue number systems with small moduli and simple convertersIn this paper, a new class of Hierarchical Residue Number Systems (HRNSs) is proposed, where the numbers are represented as a set of residues modulo factors of 2k± 1 and modulo 2k. The converters between the proposed HRNS and the positional binary number system can be built as 2-level structures using efficient circuits designed for the RNS (2k- 1, 2k, 2k+ 1). This approach allows using many small moduli in arithmetic channels without large conversion overhead. The advantages resulting from the use of the proposed HRNS depend on the possibility of factorisation of moduli 2k± 1.
KHM clustering technique as a segmentation method for endoscopic colour images
Authors: Frąckiewicz Mariusz , Palus Henryk 
Published: March 2011

KHM clustering technique as a segmentation method for endoscopic colour imagesIn this paper, the idea of applying thek-harmonic means (KHM) technique in biomedical colour image segmentation is presented. Thek-means (KM) technique establishes a background for the comparison of clustering techniques. Two original initialization methods for both clustering techniques and two evaluation functions are described. The proposed method of colour image segmentation is completed by a postprocessing procedure. Experimental tests realized on real endoscopic colour images show the superiority of KHM over KM.
Infrared receptors in pyrophilous (“fire loving”) insects as model for new un-cooled infrared sensors
Authors: Klocke David , Schmitz Anke , Soltner Helmut , Bousack Herbert , Schmitz Helmut 
Published: March 2011

Beetles of the genus Melanophila and certain flat bugs of the genus Aradus actually approach forest fires. For the detection of fires and of hot surfaces the pyrophilous species of both genera have developed infrared (IR) receptors, which have developed from common hair mechanoreceptors. Thus, this type of insect IR receptor has been termed photomechanic and shows the following two special features: (i) The formation of a complex cuticular sphere consisting of an outer exocuticular shell as well as of a cavernous microfluidic core and (ii) the enclosure of the dendritic tip of the mechanosensitive neuron inside the core in a liquid-filled chamber. Most probably a photomechanic IR sensillum acts as a microfluidic converter of infrared radiation which leads to an increase in internal pressure inside the sphere, which is measured by a mechanosensitive neuron.A simple model for this biological IR sensor is a modified Golay sensor in which the gas has been replaced by a liquid. Here, the absorbed IR radiation results in a pressure increase of the liquid and the deflection of a thin membrane. For the evaluation of this model analytical formulas are presented, which permits the calculation of the pressure increase in the cavity, the deformation of the membrane and the time constant of an artificial leak to compensate ambient temperature changes. Some organic liquids with high thermal expansion coefficients may improve the deflection of the membrane compared to water.
Process synthesis and optimization of biorefinery configurations
Authors: Pham Viet , El‐Halwagi Mahmoud 
Published: March 2011

AbstractRecently, there has been a growing interest in the development of cost‐effective technologies for the production of biofuels. A common approach to biofuel research is to invent or improve a biochemical or thermochemical conversion step. Subsequently, other conversion and separation steps are added to form a complete biorefinery flowsheet. Because this approach is structured around a specific conversion step, it may limit the possibilities of configuring optimal and innovative biorefineries. This article proposes a novel and systematic two‐stage approach to the synthesis and optimization of biorefinery configurations, given available feedstocks and desired products. In the synthesis stage, a systems‐based approach is developed to create a methodical way for synthesizing integrated biorefineries. This method is referred to as “forward‐backward” approach. It involves forward synthesis of biomass to possible intermediates and reverse synthesis starting with the desired products and identifying necessary species and pathways leading to them. In the optimization stage, Bellman's principle of optimality is applied to decompose the optimization problem into subproblems in which an optimal policy of available technologies is determined for every conversion step. An optimization formulation is utilized to determine the optimal configuration based on screening and connecting the optimal policies and generating the biorefinery flowsheet. A case study of alcohol‐producing pathways from lignocellulosic biomass is solved to demonstrate the merits of the proposed approach. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Dynamic risk analysis using alarm databases to improve process safety and product quality: Part II—Bayesian analysis
Authors: Pariyani Ankur , Seider Warren D. , Oktem Ulku G. , Soroush Masoud 
Published: March 2011

AbstractPart II presents step (iii) of the dynamic risk analysis methodology; that is, a novel Bayesian analysis method that utilizes near‐misses from distributed control system (DCS) and emergency shutdown (ESD) system databases—to calculate the failure probabilities of safety, quality, and operability systems (SQOSs) and probabilities of occurrence of incidents. It accounts for the interdependences among the SQOSs using copulas, which occur because of the nonlinear relationships between the variables and behavior‐based factors involving human operators. Two types of copula functions, multivariate normal and Cuadras–Augé copula, are used. To perform Bayesian simulation, the random‐walk, multiple‐block, Metropolis–Hastings algorithm is used. The benefits of copulas in sharing information when data are limited, especially in the cases of rare events such as failures of override controllers, and automatic and manual ESD systems, are presented. In addition, product‐quality data complement safety data to enrich near‐miss information and to yield more reliable results. Step (iii) is applied to a fluidized‐catalytic‐cracking unit (FCCU) to show its performance. © 2011 American Institute of Chemical Engineers AIChE J, 2012