bluuebunny/crossref_metadata_2025 huggingface dataset:
QSAR Modelling of Rat Acute Toxicity on the Basis of PASS Prediction
Authors: Lagunin Alexey , Zakharov Alexey , Filimonov Dmitry , Poroikov Vladimir
Published: March 2011

The method for QSAR modelling of rat acute toxicity based on the combination of QNA (Quantitative Neighbourhoods of Atoms) descriptors, PASS (Prediction of Activity Spectra for Substances) predictions and self‐consistent regression (SCR) is presented. PASS predicted biological activity profiles are used as independent input variables for QSAR modelling with SCR. QSAR models were developed using LD50 values for compounds tested on rats with four types of administration (oral, intravenous, intraperitoneal, subcutaneous). The proposed method was evaluated on the set of compounds tested for acute rat toxicity with oral administration (7286 compounds) used for testing the known QSAR methods in T.E.S.T. 3.0 program (U.S. EPA). The several other sets of compounds tested for acute rat toxicity by different routes of administration selected from SYMYX MDL Toxicity Database were used too. The method was compared with the results of prediction of acute rodent toxicity for noncongeneric sets obtained by ACD/Labs Inc. The test sets were predicted with regards to the applicability domain. Comparison of accuracy for QSAR models obtained separately using QNA descriptors, PASS predictions, nearest neighbours’ assessment with consensus models clearly demonstrated the benefits of consensus prediction. Free available web‐service for prediction of LD50 values of rat acute toxicity was developed: http://www.pharmaexpert.ru/GUSAR/AcuToxPredict/
Retrospective Mapping of SAR Data for TTR Protein in Chemico‐Biological Space Using Ligand Efficiency Indices as a Guide to Drug Discovery Strategies
Authors: Blasi Daniel , Arsequell Gemma , Valencia Gregori , Nieto Joan , Planas Antoni , Pinto Marta , Centeno Nuria B. , Abad‐Zapatero Cele , Quintana Jordi
Published: March 2011

We have previously reported the design and synthesis of ligands that stabilize Transthyretin protein (TTR) in order to obtain therapeutically active compounds for Familial Amyloid Polyneuropathy (FAP). We are hereby reporting a drug design strategy to optimize these ligands and map them in Chemico‐Biological Space (CBS) using Ligand Efficiency Indices (LEIs). We use a binding efficiency index (BEI) based on the measured binding affinity related to the molecular weight (MW) of the compound combined with surface‐binding efficiency index (SEI) based on Polar Surface Area (PSA). We will illustrate the use of these indices, combining three crucial variables (potency, MW and PSA) in a 2D graphical representation of chemical space, to perform a retrospective mapping of SAR data for a current TTR inhibitors database, and we propose prospective strategies to use these efficiency indices and chemico‐biological space maps for optimization and drug design efforts for TTR ligands.
The process and effect of supportive message expression and reception in online breast cancer support groups
Authors: Kim Eunkyung , Han Jeong Yeob , Moon Tae Joon , Shaw Bret , Shah Dhavan V. , McTavish Fiona M. , Gustafson David H.
Published: March 2011

Objective: To better understand the process and effect of social support exchanges within computer‐mediated social support (CMSS) groups for breast cancer patients, this study examines (1) the dynamic interplay between emotional support giving and receiving and (2) the relative effects of emotional support giving and receiving on patients' psychosocial health outcomes.

Methods: Data was collected from 177 patients who participated in online cancer support groups within the Comprehensive Health Enhancement Support System (CHESS) during the 4‐month intervention. Data included (1) pretest and/or post‐test survey scores of demographic, disease‐related, and psychosocial factors, (2) automatically collected CHESS usage data, and (3) computer‐aided content analysis of social support messages posts.

Results: Hierarchical regression analyses revealed that those who receive higher levels of support from others have fewer breast cancer‐related concerns (β = − 0.15, p<0.05), while those who give higher levels of support to others reframe their own problems in a positive light and adopt more positive strategies for coping (β = 0.16, p<0.05). In addition to these positive effects, partial correlation analysis indicated that these two supportive behaviors are reciprocal.

Conclusions: We concluded that supportive exchanges of receiving and giving play positive, but different, roles in predicting psychosocial health outcomes. Moreover, emotional support giving and receiving tend to reinforce each other. Our findings help practitioners, health‐care providers, and health system designers make sense of diverse social support processes among cancer patients participating within CMSS groups. Copyright © 2011 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering from gold deposited mesoporous silicon
Authors: Miyagawa Ryohei , Fukami Kazuhiro , Sakka Tetsuo , Ogata Yukio H.
Published: March 2011

As an SERS‐active template, Au deposited mesoporous Si was prepared by anodization of Si in hydrofluoric acid solution, followed by the displacement deposition of Au in solution containing Au(S2O3). The size and dispersion of deposited Au particles became small as the concentration of Au ions and the immersion duration decreased. The SERS‐activity measured with rhodamine 6G as the target molecule was affected by the morphology of Au deposits.
High quality 3D shapes by silicon anodization
Authors: Ivanov Alexey , Kovacs Andras , Mescheder Ulrich
Published: March 2011

In this paper some process considerations and optimizations of anodization for three‐dimensional (3D)‐structuring of silicon are discussed. For the shape controlling of etched form different approaches, such as frontside masking design, local backside doping and surface pre‐structuring are presented. Influences of the opening size and etch depth on the shape of the etching form are investigated. The surface quality of the resulting 3D structures is critically dependent on the specific process parameters and process flow. Best surface quality was obtained for electropolishing in 7 wt.% hydrofluoric acid (HF) at applied current densities of 100–300 mA/cm2. Application of 3D silicon forms for injection moulding is demonstrated and further implementations of the process for optical and fluidic devices are discussed.

magnified image

3D silicon shapes fabricated using anodization process with local backside doping design.
On the way to meet the experimental observation of persistent current in a mesoscopic cylinder: A mean field study
Authors: Maiti Santanu K.
Published: March 2011

The behavior of persistent current in a mesoscopic cylinder threaded by an Aharonov–Bohm flux ϕ is carefully investigated within a Hartree–Fock mean field approach. We examine the combined effect of second‐neighbor hopping integral and Hubbard correlation on the enhancement of persistent current in presence of disorder. A significant change in current amplitude is observed compared to the traditional nearest‐neighbor hopping model and the current amplitude becomes quite comparable to experimental realizations. Our analysis is found to exhibit several interesting results which have so far remained unaddressed.
Efficient interdigitated back‐contacted silicon heterojunction solar cells
Authors: Mingirulli Nicola , Haschke Jan , Gogolin Ralf , Ferré Rafel , Schulze Tim F. , Düsterhöft J. , Harder Nils‐Peter , Korte Lars , Brendel Rolf , Rech Bernd
Published: March 2011

We present back‐contacted amorphous/crystalline silicon heterojunction solar cells (IBC‐SHJ) on n‐type substrates with fill factors exceeding 78% and high current densities, the latter enabled by a SiNx /SiO2 passivated phosphorus‐diffused front surface field. Voc calculations based on carrier lifetime data of reference samples indicate that for the IBC architecture and the given amorphous silicon layer qualities an emitter buffer layer is crucial to reach a high Voc, as known for both‐side contacted silicon heterojunction solar cells. A back surface field buffer layer has a minor influence. We observe a boost in solar cell Voc of 40 mV and a simultaneous fill factor reduction introducing the buffer layer. The aperture‐area efficiency increases from 19.8 ± 0.4% to 20.2 ± 0.4%. Both, efficiencies and fill factors constitute a significant improvement over previously reported values. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Constraint‐based human resource allocation in software projects
Authors: Kang Dongwon , Jung Jinhwan , Bae Doo‐Hwan
Published: March 2011

Resource allocation in a software project is crucial for successful software development. Among various types of resources, human resource is the most important as software development is a human‐intensive activity. Human resource allocation is very complex owing to the human characteristics of developers. The human characteristics affecting allocation can be grouped into individual‐level characteristics and team‐level characteristics. At the individual level, familiarity with tasks needs to be taken into account as it affects the performance of developers. In addition, developers have different levels of productivity, depending on their capability and experience; the productivity of developers also varies according to tasks. At the team level, characteristics such as team cohesion, communication overhead, and collaboration and management also affect human resource allocation. As these characteristics affect the efficiency of project execution, we treat them as constraints of human resource allocation in our approach. We identify individual‐level constraints and team‐level constraints based on the literature and interviews with experts in the industry. With these constraints, our approach optimizes the scheduling of human resource allocations, resulting in more realistic and efficient allocations. We also provide a guideline supporting various factors, with respect to roles and module characteristics, to estimate the productivity of developers based on COCOMO II. As productivity data are hard to obtain and manage, our guideline can provide a useful direction for human resource allocation in case of software projects. To validate our proposed approach, we document a case study using real project data. Copyright © 2011 John Wiley & Sons, Ltd.
Impact of Combined Feedback–Feedforward Control‐Based Ordering Policies on Supply Chain Stability and Responsiveness
Authors: Chaudhari Gaurav S. , Sturges Robert H. , Sandu Corina
Published: March 2011

The design of ordering policies for inventory management in supply chains has traditionally relied on the proportional feedback control structure as a foundation for the design process. Consequently, the impact of ordering policies that use both proportional–integral–derivative feedback control and feedforward control has been relatively unexplored. We evaluate the impact of ordering policies based on the combined control structure on supply chain stability and responsiveness. Copyright © 2011 John Wiley & Sons, Ltd.
Peer educators responding to students with mental health issues
Authors: Daddona Mark F.
Published: March 2011

As more college students face severe mental health issues, peer educators need effective communication skills and knowledge of campus counseling services to properly make referrals while continuing the peer relationship. Emotional support must also be provided for the peer educators.
Peer education in student leadership programs: Responding to co‐curricular challenges
Authors: Haber Paige
Published: March 2011

The use of peer educators is standard in many student leadership development programs. This chapter includes an overview of leadership theory, leadership research, and considerations for designing curricular and co‐curricular peer leadership programs.
Analyse von Deskriptorsystemen mit Hilfe von Berechnungsgraphen
Authors: Reinschke K. J. , Röbenack K.
Published: March 2011

Der Beitrag ist der graphentheoretischen Analyse von Deskriptorsystemen mit unbestimmten Parametern gewidmet. Die Deskriptorgleichungen werden als Berechnungsabläufe interpretiert und im Berechnungsgraphen veranschaulicht. Mit Hilfe des Berechnungsgraphen und des zugehörigen Ableitungsgraphen lassen sich wichtige Charakteristiken bei linearen Deskriptorsystemen graphentheoretisch deuten und durch Inspektion der Graphen ermitteln. Ableseregeln für die Dimension des langsamen Teilsystems, die Anzahl und die Größe der Jordan‐Blöcke des schnellen Teilsystems und für die strukturellen Steuerbarkeitsmerkmale werden formuliert. Anhand der graphentheoretischen Bestimmung des relativen Grades wird gezeigt, daß Berechnungsgraphen an Kombination mit den Ableitungsgraphen auch für die Analyse nichtlinearer dynamischer Systeme nützlich sind.
Microstructural Decomposition Error Estimates
Authors: Zohdi T. , Wriggers P.
Published: March 2011

Computational simulations of interacting microstructure in solid structures, with methods such as the finite element method, require solutions to numerically enormous boundary value problems. The primary objective of this work is to introduce a‐posteriori error bounds for a domain decomposition which can be used to reduce the computational complexity of boundary value problems associated with such simulations. The approach is to partition and decouple the heterogeneous body into more computationally tractable, nonoverlapping, subdomains whose union forms the entire domain under analysis. This is achieved by computing a relatively inexpensive auxiliary „decoupling problem”︁ with regularized coefficients but with the same external geometry and loading as the original body. The solution to the decoupling problem is then used to construct local boundary data for the subdomains, which can thereafter be solved independently, possibly in parallel.
Influence of Non‐newtonian Flow Behavior on Local Hemodynamics
Authors: Perktold K. , Karner G. , Leuprecht A. , Hofer M.
Published: March 2011

The influence of non‐Newtonian blood flow in large arteries is studied numerically. The model studies are carried out to demonstrate the shear thinning effect at increased shear rates resulting from the reversible destruction of red blood cell aggregates and to show basic viscoelastic effects. The mathematical models considered use the conservation of momentum and of mass and constitutive relations describing the shear thinning behavior and relations of Jeffreys type (Oldroyd‐B model). The numerical approach applies the finite element method. The non‐Newtonian inelastic effects are demonstrated in a curved tube model and in an anatomically and physiologically realistic artery bifurcation model. The viscoelastic flow study is carried out using an axisymmetric tube with a local constriction modeling a stenosed blood vessel. The assumption of physiologically realistic shear thinning behavior shows a minor quantitative influence on local flow patterns compared with Newtonian reference flow.
Modelling Finite Deformation of Polycrystals Using Local Objective Frames
Authors: Forest S. , Pilvin P.
Published: March 2011

The formulation of constitutive models at finite strain using local objective frames is applied to solids with microstructure. Priviledged space frames are introduced at both the material level and the micro structure level. For single crystals, the method leads to a model almost equivalent to Mandel's theory. For polycrystals, an explicit concentration rule written in the corotational frame is proposed. Simulations of texture evolutions are then presented.
Experimentelle Untersuchungen der Nachlaufströmung eines stumpfen Körpers mit einfacher Geometrie
Authors: May F. , Schwarz V.
Published: March 2011

Die Nachlaufströmung eines Grundkörpers mit rundem Querschnitt und stumpfem Heck wurde mit Windkanalmessungen experimentell untersucht. Ferner wurden die Wirkungen von Maßnahmen im Nachlauf des Körpers auf den Widerstand des Körpers und auf die Wirbeldynamik dm Nachlauf analysiert. Bei den untersuchten Maßnahmen handelte es sich um eine kreisförmige Nachlaufscheibe, die parallel zur Basisfläche angeordnet war und um ein Gleichrichterkreuz. Die Widerstandsbeiwerte des Körpers in den verschiedenen Konfigurationen wurden mittels ei‐ner Windkanalwaage ermittelt. Die Wirbeldynamik wurde unter Verwendung von Hitzdrahtmessungen im Nachlauf des Körpers analysiert. Dazu waren acht Hitzdrahtsonden kreisförmig im Nachlauf angeordnet. Zusätzlich wurden mit Hitzdrahtsonden in gerader Anordnung die zeitlich gemittelten Nachlaufdellen der einzelnen Konfigurationen bestimmt. Die Messungen zeigten, daß sowohl mit der Nachlaufscheibe als auch mit dem Gleichrichterkreuz eine Widerstandsreduktion erzielt wird, die Auswertung der Hitzdrahtmessungen ergab jedoch, daß die Wirkungsprinzipien dieser Maßnahmen völlig unterschiedlich sind.
On the flow around a circular cylinder. Part II: Turbulent regime
Authors: Noack B. R.
Published: March 2011

A concise review about the properties of the turbulent flow (260 < Re < 107) around a circular cylinder is presented. Some open problems of this flow are outlined.
Comparison of the tangent model predictions to finite element results for the solution of the inclusion problem in viscoplasticity
Authors: Molinari A. , El‐Houdaigui F. , Tóth L. S.
Published: March 2011

Using the tangent viscoplastic model of Molinari, Canova and Abzi (1987) in its general anisotropic formulation, the strain localisation behaviour of spherical inclusions is examined for the case of von Mises type viscoplastic creep. The obtained results are compared to the finite element results of Gilormini and Germain (1987) and good agreements have been obtained.
Finite Element Modeling of 3D Elastic‐Elastic Rolling Contact
Authors: Nackenhorst U. , Zastrau B. W. , Jarewski J.
Published: March 2011

The three dimensional rolling contact of elastic bodies is simulated numerically by a finite element approach. The relative kinematics is described by an Arbitrary Lagrangian Eulerian description. Special emphasis has to be laid onto the tangential contact condition because the slip, i.e. the relative tangential displacement of the contacting particles, is not obtained a priory. Numerical examples from the railway wheel rolling on the rail underline the applicability of the suggested method.
On Smooth Finite Element Discretizations for Frictional Contact Problems
Authors: Wriggers P. , Krstulovič‐Opara L.
Published: March 2011

2D frictional polynomial node to segment contact elements are developed using the Mathematica SMS (Symbolic Mechanics System) package. The weak formulation and the penalty method are used for the description of large deformation frictional contact problems. Presented approach, based on non‐associated frictional law and elastic‐plastic tangential slip decomposition, is resulting into the quadratic rate of convergence within Newton‐Raphson iteration loop.
Resonant wave response to obstacle forcing in two layer fluid flow
Authors: Cox E. A. , Kluwick A. , Scheichl S T.
Published: March 2011

The paper is concerned with the propagation of weakly nonlinear gravity waves in a two layer fluid over bottom topography when the fluid is assumed to be inviscid and incompressible. Specifically, we investigate disturbances of a homogeneous critical state. As a consequence, the resulting (free surface or internal) wave is trapped which leads to a resonant wave response to obstacle forcing. In general the wave motion is found to be governed by a kinematic wave equation with quadratic nonlinearity where the bottom topography enters as a source term. In the case of internal waves, however, there exists a flow regime in which both quadratic and cubic nonlinear terms have to be taken into account.
Constitutive relations for thermo‐elastic porous solids
Authors: Bluhm J.
Published: March 2011

Bused on the theory of porous media (TPM), constitutive relations for the so‐called “effective” stresses of the thermo‐elastic compressible or incompressible solid phase of a fluid saturated or an empty porous solid will be presented. For the description of a compressible solid within the framework of finite deformation processes, well‐known constitutive laws for one‐component materials can be used. For incompressible porous solids, one has to consider that the so‐culled compression point exists (in this point all pores are closed and no further volume compression can occur). With respect to the description of the aforementioned effect, constitutive relations for incompressible solids are developed following the structure of the constitutive laws for compressible solids.
Application of Minkowski Space to Description of Anisotropic Pore Space Structure in Porous Materials
Authors: Cleszko M.
Published: March 2011

The subject of this note is the modelling of an anisotropic pore space structure in rigid porous materials capable of fluid flow through its pores. In this paper, the new macroscopic model of a saturated porous medium is proposed in which a fluid flow through porous skeleton of an anisotropic pore structure is considered as a motion of the material continuum in the plane anisotropic metric space ‐ Minkowski space ‐ immersed in a Euclidean one that is used as the model of the physical space. This model takes into consideration the fundamental fact, concerning kinematics of a fluid‐saturated porous solid, that the pore space of permeable skeleton forms the real space for a fluid motion and its structure imposes restrictions on that motion.

The metrics of Minkowski and Euclidean spaces are applied in the paper to determine the respective measures of any line, surface, and volume elements. The new metric tensors of surface and volume elements in these spaces have been proposed that are directly related to the metric tensors of distance. This enables one to define the geometrical parameters characterising pore structure of such materials.: the tortuosity, the volume, and surface porosity. It has been shown that the structure of isotropic pore space of porous materials is described only by two independent scalar parameters.
A Mixture Theory for Microstructured Porous Media
Authors: Pasquale Giovine
Published: March 2011

A porous continuum with very large lacunae, partially saturated by a fluid inclusion, as described by means of a new immiscible mixture which consists of a medium with ellipsoidal microstructure and of a classical fluid.
A contact zone approach for an interface crack in a piezoelectric anisotropic bimaterial
Authors: Loboda V. V. , Herrmann K. P.
Published: March 2011

An exact analytical solution for an interface crack with an artificial contact zone situated between two piezoelectric semi‐infinite spaces has been found. The classical interface crack model and the contact zone model can be obtained as particular cases of this solution. Analytical relationships between the fracture mechanical parameters of these different models are given. On the base of these relations a numerical algorithm has been developed for the determination of fracture mechanical parameters at an interface crack tip situated in the material interface of a finite‐sized anisotropic piezoelectric bimaterial.
An Asymptotic Method for Effective Properties of Visco‐Elastic Composite Materials
Authors: Aadrianov I. V. , Danishevs'kyy V. V. , Toearzewski S.
Published: March 2011

We consider visco‐elastic two‐components composite materials, consisting of an infinite regular arrays of fibers inclusions embedded in a matrix. Analytical formulas for Laplace transforms of the effective shear relaxation and creep functions are derived. For this aim an asymptotic technique, based on the homogenization method, the three‐phase model, the method of boundary perturbation, Pade and quasifractional approximants, is used Obtained results also allow us to evaluate the effective complex shear modulus and loss tangent for stationary harmonic oscillations of considered composite material. Derived solutions are valid for all values of the components concentrations and properties. Our method may be effectively used for determining various effective properties of visco‐elastic composite materials with different inclusions geometries.
State Diagram of fine cohesive powders at zero shear
Authors: Castellanos A. , Valverde J. M. , Watson P. K.
Published: March 2011

We present measurements of the tensile strength for a set of model toners, with a typical diameter of 10 microns, as a function of the consolidation stress and void fraction. The technique used to change the consolidation state is to centrifuge the powder. For each consolidation state the tensile strength is measured by subjecting the powder to a tensile stress by means of a direct gas flow. The average free volume is calculated by measuring the powder bed height by means of an ultrasonic device. All these processes allow us to draw the State Diagram of the powder at zero shear. The influence of the hardness, and size of the asperities, both controlled by flow control additives, as well as the influence of the radius of the particle, is determined, We find that, contrary to the case of low consolidations where the tensile strength was a linear function of the consolidation stress, at high consolidation stresses the tensile strength is a sublinear function of the compressive stresses.
Numerical Study of the Flow of Sheet Metal Between Circular Drawbeads
Authors: Courvoisier L. , Martiy M. , Ferron G.
Published: March 2011

This paper analyses the evolutions of stresses and strains for a sheet metal band plastically deformed along a drawbead. Numerical simulations are conducted to model the process of drawing and to study the mechanics of drawbead process of drawing and to study the mechanics of drawbead restraint.
Stress‐induced martensitic transformation in polycrystalline alloys
Authors: Patoor E. , Entemeyer D. , Eberhardt A. , Berveillxr M.
Published: March 2011

Modern scale transition methods developed in mechanics of materials these last years are successfully applied to model the particular behaviour exhibited by shape memory alloys. Starting from a local kinematical analysis based on crystallographic considerations and determining the thermodynamical forces associated to the martensitic phase transformation local relationships are determinde using the self‐consistent approximation. This framework is applied to simulate different loading conditions using mechanical of thermal loading paths with uniaxial of multiaxial conditions. Results such obtained are compared with experimental results.
Pseudoelastic NiTi‐Alloys under Cyclic Loading
Authors: Schmidt I. , Lammerling R.
Published: March 2011

In addition to the shape memory effect, shape memory alloys show two further properties that are useful for mechanical applications: pseudoelasticity and a very high damping capacity compared to other metals. Beside the temperature both characteristics depend on the amplitude and rate of the mechanical load, as well as on the load history. In cyclic tensile tests the mechanical behaviour of binary NiTi‐alloys is investigated in order to make use of them in engineering applications.
The ε‐Relaxed Approach in Topology Optimization for Various ε Functions
Authors: Kutylowski R.
Published: March 2011

The inspiration of this contribution was a paper written by Cheng and Guo ]1[ where the E‐relaxed approach for structural topology optimization was applied and a second one paper by Duysinx and Bendsoe ]2[ where continuum structure with stress constraints was considered. In this contribution various ε functions are proposed and discussed for continuum structure from the convergence point of view. The problem is illustrated by FEM examples.
Temporal Commutation Errors in Large‐Eddy Simulation
Authors: Franke J. , Frank W.
Published: March 2011

The spatial filtering applied in large eddy simulations leads to additional closure problems if the filter width varies in space and time. While the spatial commutation error has been examined, the temporal commutation error has not been studied, despite its relevance for in‐cylinder flow simulations ]1[. Here some theoretical results for the temporal commutation error are presented. It is shown that a temporally varying domain leads to an additional constraint on the filter function. The results are illustrated for a simple scalar problem.
On the Distribution of the Zeros of Polynomials Related to the Daubechies Wavelets
Authors: Boese F. G.
Published: March 2011

To locate all zeros of the polynomials qn(z) from (1) as precise as possible is our aim. These polynomials are related to the sequence of Daubechies wavelets. Zero enclosures up to a separation of all zeros are communicated. The enclosing sets are conformal lemniscate rectangles.
The Two‐Sided Lid‐Driven Cavity: Aspect‐Ratio Dependence of the Flow Stability
Authors: Blohm C. , Albensoeder S. , Kuhlmann H. C. , Broda M. , Rath H. J.
Published: March 2011

The transition from two‐dimensional (2D) steady to three‐dimensional (3D) flow is investigated experimentally in a two‐sided lid‐driven cavity for anti‐parallel motion of two facing walls. Both wall speeds (Reynolds numbers) have the same absolute value. We present critical Reynolds numbers at the onset of steady three‐dimensional flow as a function of the cross‐sectional aspect ratio. The critical curve is composed of different neutral branches belonging to different instability modes. Comparison with numerical results enables insight into the corresponding mechanisms.
Linear Stability Theory of Non‐Isothermal Flow Between Two Rotating Disks
Authors: Tuliszka‐Sznitko Ewa , Soong Chyi‐Yeou
Published: March 2011

The objective of the present study is to investigate the flow stability of mixed convection in non‐isothermal rotating fluids between a rotating disk and a stationary one. The buoyancy effects stemmed from the rotational forces, including centrifugal and Coriolis, are taken into account. A similarity model of thermal flow with the assumption of Boussinesq fluids is formulated for generating axially symmetric solutions of the basic state. Disturbance equations are derived by using the concept of small perturbation of normal mode expressions, and then solved by the Chebyshev collocation spectral method. The influences of the rotation‐induced buoyancy effects and the rotational conditions on the flow stability characteristics of the two‐disk rotating fluid motion are explored. The present results disclose the mechanisms and the significance of the rotation‐induced buoyancy on flow stability characteristics of the non‐isothermal fluids in the rotor‐stator disk systems.
Creeping Newtonian Film Flow Down an Inclined Wavy Plane. Part II
Authors: Wierschem A. , Scholle M. , Aksel N.
Published: March 2011

We consider the creeping film flow down an inclined wavy plane. For large wavelengths and thin films we consider two different approaches depending on the order of the amplitude of the wavy bottom profile and compare them to experimental results.
Heat transfer from hot wires at small forced‐flow velocities
Authors: Henselowsky C. , Kuhlmann H. C. , Rath H. J.
Published: March 2011

At very low velocities (v ≤ 0.1 m/s), hot‐wire measurements are significantly influenced by free convection. To assess the contribution of free‐convection heat transfer to the heat balance of hot‐wire probes, measurements under gravitational and under microgravity conditions are compared in a velocity range 0 ≤ v ≤ 0.3 m/s corresponding to a Reynolds number range Re ≤ 0.1. The measurements were made with horizontal hot‐wire probes in cross flow in air at 21.8°C. For creeping flow three distinct regions can be observed in which different factors dominate the heat transport. While free convection prevails at Re = 0, forced convection dominates for Re > Gr1/3. At intermediate Reynolds numbers both transport mechanisms must be considered.
Stability of thermocapillary flow in cylindrical liquid bridges: Rotation of the hot disk
Authors: Lee Y.‐S. , Kuhlmann H. C. , Rath H. J. , Chun Ch.‐H.
Published: March 2011

The thermocapillary flow in a differentially heated cylindrical liquid bridge under steady rotation of the hot disk is considered in the limit of zero capillary number. Steady flow states and their three‐dimensional stability are calculated numerically. It is shown that the vortex breakdown caused by the rotation is strongly affected by the thermocapillary flow. A linear stability analysis reveals that the most dangerous perturbations are oscillatory with azimuthal wavenumber m = 1 or m = 2 depending on the parameters.
Combustion of the Diesel Fuel Spray
Authors: Marcic M. , Zgonik M. , Avsec J.
Published: March 2011

The paper deals with the computer simulation of the Diesel fuel spray combustion under the similar conditions as in Diesel engines. A mathematical model of the spray propulsion and combustion is treated which allows the observation of the phenomena in the spray during its movement through air. Fuel droplets of the spray are vaporized due to the transfer of heat from hot air. In a certain moment when required conditions are met selfignition of mixture occurs. In order to determine the points where selfignitions occurs first, we have introduced the term “ignition probability” referring to the local air ratio and fuel dispersion in the spray.
Schalltransmission durch Isolierfenster
Authors: Langer S. , Antes H.
Published: March 2011

Der Nachweis der Schalldämmwirkung von Isolierfenstern erfolgt bisher im Allgemeinen durch Messungen unter normierten Bedingungen, obwohl eine numerische Simulation schneller und effektiver wäre. Deshalb wird dafür hier ein Berechnungsmodell entwickelt, dass die Schallwellenausbreitung und den Schalldurchgang durch zweifach‐verglaste Fenster sowie alle auftretenden dynamischen Wechselwirkungsvorgänge beinhaltet.

Dazu wird sowohl für die Biegewellen der als elastische, dünne Kirchhoff‐Platten modellierten Glasscheiben wie für die Schalldruckwellen in der Luft der Scheibenzwischenräume und des Gebäudeinnenraums die Finite‐Element‐Methode (FEM) verwendet. Die Umgebung ausserhalb des Gebäudes stellt ein halbunendliches Gebiet dar, so dass wegen der Abstrahlbedingung dort die Randelementmethode (REM) bevorzugt wird. Die Kopplung der Fluidgebiete mit den Glasscheiben erfolgt jeweils über die virtuellen Arbeiten an den Koppelflächen. Die Lösung liefert sowohl das dynamische Verhalten der Glasscheiben wie die Schalldruckverteilung in der Luft. Damit ist dort der Schallpegel bekannt und kann das Schalldämm‐Maß des Fensters ermittelt werden.
Hochgenaue Konturliniengenerierung
Authors: Callies M. , Callies R.
Published: March 2011

Automatisierte Meßverfahren tasten Gegenstände mit hoher Genauigkeit ab. Die entstehenden Datenmengen sind für eine direkte Weiterverarbeitung in FE‐Programmen zu umfangreich. Ein datenreduzierender, auf multivariates, NURBS basierender Ansatz wird vorgestellt, mit dem sich Konturkurven und‐flächen mit hoher Präzision aus Meßwerten ableiten lassen. Die Approximationsqualität wird zur strikt an die Größe der Meßfehler angepaßten mathematischen Nebenbedingung, unter der die primären Zielfunktionale zu optimieren sind. Lokal adaptive Verfeinerungen erhöhen signifikant die Flexibilität der Ansätze. Alle Schritte unterliegen einer strikten Optimierung über SQP‐Verfahren. Beispielhaft wird die automatische Präzisionsauswertung von Schichtbildern aus der Computertomographie vorgestellt. Man erreicht Approximationsgenauigkeiten der Konturlinien von 0.05 mm bei einer Datenreduktion um mehr als den Faktor 5.
Numerical analysis of the polygonalization of railway wheels
Authors: Langemann Dirk
Published: March 2011

The formation of irregular wear patterns on wheels in high‐speed trains is an important problem because it affects negatively the convenience of passengers and increases maintenance costs. Finally, nonhomogeneous contact geometry leads to considerable variations of loading conditions and is hence a security hazard.

An algorithm is presented to analyze the development of irregular wear patterns quantitatively and to predict wear formation of wheel/rail‐systems. It is based on the concept of ergodicity and it is time‐expensive but reliable. The algorithm is applied on a 3D‐model using different parameters.
Statistical Linearization of the Duffing Oscillator under non‐Gaussian Excitations with Criteria in Probability Density Function Space
Authors: Socha Leslaw
Published: March 2011

The concept of statistical linearization with probability density criteria for nonlinear oscillator under non‐Gaussian excitations is considered in this paper. New criteria of linearization and an approximate approach is proposed.
A REVISION OF PHILIPPINE GARDENIA (RUBIACEAE)
Authors: Wong K. M. , Low Y. W.
Published: March 2011

A description of the defining characteristics of Gardenia (Rubiaceae) and a revision of the Philippine species distinguished mainly by calyx morphology are presented. A key to five species of Gardenia recognised for the Philippines, full descriptions and illustrations, and a list of names which should be excluded from Gardenia are given. Relevant Philippine names for which holotypes were not indicated or have been destroyed are lectotypified. Two new endemic species, Gardenia ornata K.M.Wong and G. vulcanica K.M.Wong, are described. Gardenia elata Ridl. and G. mutabilis Reinw. ex Blume are newly applied to Philippine species previously enumerated under other names. Gardenia pseudopsidium (Blanco) Fern.-Vill. is considered a doubtful name, to which some authors have referred the endemic G. barnesii Merr.
REVISION OF THE LIMITS OF PEDICULARIS SERIES MEGALANTHAE (PRAIN) BONATI (OROBANCHACEAE)
Authors: Mill R. R.
Published: March 2011

The limits of Pedicularis L. ser. Megalanthae (Prain) Bonati (Orobanchaceae) are revised. The series, typified by Pedicularis megalantha D.Don, is restricted to seven species chiefly inhabiting the eastern Sino-Himalayan region. Authorship of the name Megalanthae at series rank is ascribed to Bonati (Mém. Soc. Bot. France 18: 13, 1910) because the groups recognised by Prain in 1890, that have been traditionally regarded as series, are in fact rankless. Two species of the NW Himalayan region, Pedicularis bicornuta Klotzsch and P. elephantoides Benth., are removed from P. ser. Megalanthae as they differ significantly from the eastern species in their floral morphology. These species are considered sufficiently distinct to warrant recognition as the new series Pedicularis ser. Bicornutae R.R.Mill. This new series is provisionally assigned to Pedicularis sect. Phanerantha H.L.Li. Pedicularis bicornuta, whose holotype is destroyed, and P. eximia G.Watt are lectotypified. The recently published Pedicularis bicornuta var. adenocalyx R.R.Mill includes the lectotype and much, but not all, material previously assigned to P. eximia.
Neighbourhood immigrant acculturation and diet among Hispanic female residents of New York City
Authors: Park Yoosun , Neckerman Kathryn , Quinn James , Weiss Christopher , Jacobson Judith , Rundle Andrew
Published: March 2011

Objective

To identify predominant dietary patterns among Hispanic women and to determine whether adherence to dietary patterns is predicted by neighbourhood-level factors: linguistic isolation, poverty rate and the retail food environment.

Design

Cross-sectional analyses of predictors of adherence to dietary patterns identified from principal component analysis of data collected using the Study of Women's Health Across the Nation FFQ. Census data were used to measure poverty rates and the percentage of Spanish-speaking families in the neighbourhood in which no person aged ≥14 years spoke English very well (linguistic isolation) and the retail food environment was measured using business listings data.

Setting

New York City.

Subjects

A total of 345 Hispanic women.

Results

Two major dietary patterns were identified: a healthy dietary pattern loading high for vegetables, legumes, potatoes, fish and other seafood, which explained 17 % of the variance in the FFQ data and an energy-dense dietary pattern loading high for red meat, poultry, pizza, french fries and high-energy drinks, which explained 9 % of the variance in the FFQ data. Adherence to the healthy dietary pattern was positively associated with neighbourhood linguistic isolation and negatively associated with neighbourhood poverty. Presence of more fast-food restaurants per square kilometre in the neighbourhood was significantly associated with lower adherence to the healthy diet. Adherence to the energy-dense dietary pattern was inversely, but not significantly, associated with neighbourhood linguistic isolation.

Conclusions

These results are consistent with the hypothesis that living in immigrant enclaves is associated with healthy dietary patterns among Hispanics.
Interpretation of the Nano-Electron-Diffraction Patterns along the Five-Fold Axis of Decahedral Gold Nanoparticles
Authors: Romeu L.D. , Reyes-Gasga J.
Published: March 2011

The transition from 10-fold to 5-fold symmetry was observed during the analysis of nanodiffraction patterns of a gold decahedral multiple twinned nanoparticle of 15 nm in diameter. The analysis shows that as the convergence of the beam is increased, the rotational symmetry of the diffraction pattern shifts from 10- to 5-fold. The 10-fold symmetry predicted by Friedel's law is lost by the asymmetric shift of the diffraction spots, an effect that becomes more noticeable as the electron beam convergence increases. Dynamical and kinematical diffraction calculations indicate this decrease in symmetry is the result of a double refraction effect coupled with the variation of the dynamical diffraction conditions arising from a varying electron beam convergence.
Millimeter-wave antenna designs for 60 GHz applications: SoC and SiP approaches
Authors: Calvez Christophe , Pilard Romain , Person Christian , Coupez Jean-Philippe , Gallée François , Gianesello Frédéric , Ezzeddine Hilal , Gloria Daniel
Published: March 2011

Antenna on chip (AoC) and antenna in package (AiP) solutions for millimeter-wave (mmWave) applications and their characterization are presented in this paper. Antenna integration on low resistivity (LR) and high resistivity (HR) silicon substrate are expected. And, in a packaging approach, the combination of antenna on silicon with a material, which has the effect of a “lens”, allowing increasing gain is presented. In a second part, to satisfy beamforming capabilities, a hybrid integration of the antenna on silicon and glass substrates is proposed.
Radiation mechanism and polarization properties of leaky coaxial cables
Authors: Wang Junhong , Li Yujian , Zhang Zhan , Chen Meie
Published: March 2011

Polarization properties of the leaky coaxial cables (LCXs) have significant effects on the fluctuation of the received signal. Therefore, the knowledge of the polarization state of LCXs is helpful to design LCXs with uniform radio wave coverage. In this paper, the physical understanding of the radiation from LCXs is presented first, and then a hybrid method involving finite difference time domain method and integration of equivalent electrical and magnetic currents is used to simulate and analyze the polarization properties of LCXs with circumferentially asymmetry slot. It is found that the LCXs with circumferentially asymmetry slots can excite both the circumferential and axial components of the field, and the magnitude and phase differences between them significantly depends on the structural parameters of the slot. Therefore, it is possible to design LCX with desired polarization property by properly choosing the structural parameters.
Palladium-catalyzed cascade reactions of coumarins with alkynes: synthesis of highly substituted cyclopentadiene fused chromones
Authors: Wang Lei , Peng Shiyong , Wang Jian
Published: March 2011

A palladium-catalyzed cascade reaction of coumarins with alkynes is described, which provides a new route to the synthesis of highly substituted cyclopentadiene fused chromones.
Disorder-induced exciton localization and violation of optical selection rules in supramolecular nanotubes
Authors: Vlaming S. M. , Bloemsma E. A. , Nietiadi M. Linggarsari , Knoester J.
Published: March 2011

Using numerical simulations, we study the effect of disorder on the optical properties of cylindrical aggregates of molecules with strong excitation transfer interactions. The exciton states and the energy transport properties of such molecular nanotubes attract considerable interest for application in artificial light-harvesting systems and energy transport wires. In the absence of disorder, such nanotubes exhibit two optical absorption peaks, resulting from three super-radiant exciton states, one polarized along the axis of the cylinder, the other two (degenerate) polarized perpendicular to this axis. These selection rules, imposed by the cylindrical symmetry, break down in the presence of disorder in the molecular transition energies, due to the fact that the exciton states localize and no longer wrap completely around the tube. We show that the important parameter is the ratio of the exciton localization length and the tube's circumference. When this ratio decreases, the distribution of polarization angles of the exciton states changes from a two-peak structure (at zero and ninety degrees) to a single peak determined by the orientation of individual molecules within the tube. This is also reflected in a qualitative change of the absorption spectrum. The latter agrees with recent experimental findings.
Microwave response of FeCo/carbon nanotubes composites
Authors: Han Z. , Li D. , Wang X. W. , Zhang Z. D.
Published: March 2011

Complex permittivity and permeability of FeCo/carbon nanotubes (CNTs)–paraffin composites have been investigated at microwave frequencies between 2 and 18 GHz. Percolation threshold PC of about 34 wt. % is determined in the present system by AC conductivity measurements. Microwave absorption of FeCo/CNTs–paraffin composites is enhanced when the mass ratio of the fillers approaches PC. Meanwhile, the maximum absorption shifts to thinner thicknesses and lower frequencies by increasing the filler content. The maximum absorption was found to be –37.5 dB at 11.2 GHz with a layer thickness of 8 mm in the composites with 30 wt. % FeCo/CNTs nanocomposites.
Magneto-optic properties of InAsN and InN quantum dots doped with Co or Ni atoms
Authors: Pozhar Liudmila A.
Published: March 2011

The electron energy level structure and charge and spin distributions of small InN and InAsN quantum dots (QDs) doped with Co or Ni atoms were studied using first-principle quantum many body field theoretical methods. In agreement with existing experimental findings, the obtained results show that nitrogen atoms in the studied small QDs accumulate the electron charge. It was also found that nickel atoms orchestrate electron charge redistribution necessary to stabilize such small systems.
Analytical calculation of the torque exerted between two perpendicularly magnetized magnets
Authors: Allag H. , Yonnet J.-P. , Latreche M. E. H.
Published: March 2011

Analytical expressions of the torque on cuboidal permanent magnets are given. The only hypothesis is that the magnetizations are rigid, uniform, and perpendicularly oriented. The analytical calculation is made by replacing magnetizations by distributions of magnetic charges on the magnet poles. The torque expressions are obtained using the Lorentz force method. The results are valid for any relative magnet position, and the torque can be obtained with respect to any reference point. Although these expressions seem rather complicated, they enable an extremely fast and accurate torque calculation on a permanent magnet in the presence of a magnetic field of another permanent magnet.