bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite Element Analysis of Freely Rotating Tires
Authors: Tseng N-T.
Published: June 2006

Axisymmetric analysis of an inflated tire rotating with constant angular speed can be used to simulate two loading conditions of a tire during its service life: (1) a freely rotating tire on an automobile that is stuck in snow or mud and (2) the top region of a rolling loaded tire, where footprint loading has little influence on the distribution of its stresses and strains. The equations of motion for a freely rotating deformable body with constant angular speed have been derived and implemented into a finite element code developed in-house. The rotation of a thin disk was used to check the validity of the implemented formulation and coding. Excellent agreement between the numerical and the analytical results was obtained. A cast tire, a radial automobile tire, and a radial truck tire, were then analyzed by the new finite element procedure. The tires were inflated and rotated at speeds up to 241 km/h (150 mph). The elastomers in these tires were simulated by incompressible elements for which the nonlinear mechanical properties were described by the Mooney-Rivlin model. Each ply was simulated by its equivalent orthotropic material model. The finite element predictions agreed well with the available experimental measurements. Significant changes in interply shear strain at the belt edge, the bead load, and the crown cord loads of plies were observed in the finite element analysis. These phenomena suggest three possible failure modes in freely rotating tires, i.e. belt edge separation, bead breakage, and belt failure at crown region.
Effect of Material Properties on Tire Performance Characteristics—Part I. Tire Cords
Authors: Futamura S.
Published: June 2006

The effect of modulus of tire cords in stabilizer and body plies on the performance of a radial automobile tire is discussed. Cord modulus was varied systematically by using polyester, rayon, and aramid materials. High speed, endurance, and plunger energy were not effected. Rolling resistance was higher with aramid cord than with polyester cord in the body ply, but there was no effect of cord material in stabilizer plies. Increase of cord modulus in the stabilizer ply, however, did produce significantly higher cornering coefficient. Wear resistance was also higher, especially under high severity test conditions.
A New Approach for the Thermomechanical Analysis of Tires by the Finite Element Method
Authors: Sarkar K. , Kwon Y. D. , Prevorsek D. C.
Published: June 2006

A new approach for the complete thermomechanical analysis of a pneumatic tire to estimate cyclic changes in the stresses and strains and obtain the pseudo-steady state temperature profile in a tire rolling under a load is described. The approach uses a commercially available finite element code and involves a simplified two-dimensional representation of the tire geometry to reduce computation time. The analysis includes three stages: inflation analysis, contact analysis, and temperature analysis. To handle the large deformations resulting from the inflation and contact loadings, the load is applied in small increments and a linearly elastic deformation is assumed in each increment. The structural and temperature analyses can be coupled through an iterative process to reflect the effect of temperature changes on material properties. Results obtained indicate that in spite of the simplifying assumptions made to reduce computation time, useful approximations to the solution of this complex problem can be obtained.
Load, Speed and Inflation Pressure Effects on Rolling Loss Distribution in Automobile Tires
Authors: Clark J. D. , Schuring D. J.
Published: June 2006

The effect of tire load, speed, and cold inflation pressure on the rolling loss contribution of any tire region is determined by numerical calculations involving both laboratory measurements and thermal modeling techniques. Laboratory measurements include tire surface temperature distributions obtained from an infrared camera system; thermal modeling is based on finite-difference procedures.

Results are presented in two formats: (1) plots of rolling loss distributions from bead to bead and (2) contributions of tread, shoulder, sidewall, and bead regions. The first format is a direct result of the thermal model; the second is derived from multiple-regression operations. Both formats are given as functions of load, cold inflation pressure, and speed. Beahvior in the tread region is shown to be unique.
Applications of Finite Element Analysis in Tire Design
Authors: Kenny T. M. , Stechschulte R. A.
Published: June 2006

A finite element which uses a unique approach to obtain three dimensional properties is described. The lamination model for the material uses a numerical integration technique to combine the properties of each laminate within the element. In-plane and out-of-plane coupling are predicted. The ability to calculate interply shear strains is restricted only by the chosen shape function. Illustrations are given for inflated shape, interply shear strains, and cord loads in a typical bias mud and snow tire for light trucks.
A Finite Element Analysis of Curing Bladder Shaping
Authors: Warholic T. C. , Pelle R. G.
Published: June 2006

The molding process is a critical step in the manufacture of pneumatic tires. It affects the design and consequently the performance of the tire. The present paper covers work aimed at analyzing the molding process using the finite element method. Specifically, the finite element code MARC is used to analyze the inflation of a curing bladder inside a rigid tire profile. Incompressible elements are used to model the bladder and GAP elements are used to simulate the contact between the two surfaces. Of primary interest is the bladder-profile interface, namely how contact occurs at the interface and the magnitude and uniformity of the interfacial pressures. Two different bladder shapes and two different inside tire profiles are studied. Of equal importance is the ability to model this type of contact problem as it is a significant step toward analyzing the tire molding process.
An Efficient Approach for the Three-Dimensional Finite Element Analysis of Tires
Authors: Chang J. P. , Satyamurthy K. , Tseng N. T.
Published: June 2006

The finite element analysis of tires under a vertical footprint load requires the use of three-dimensional models. The excessive CPU time required for such models, especially when the tire construction is considered in detail, makes parametric studies difficult and time-consuming. Therefore, one of the principal objectives of finite element program development is to provide an efficient tool for the three-dimensional analysis of tires so that it can be integrated into the design process effectively. In the present study, a systematic finite element procedure is developed for solving loaded tire problems. The principal elements of this procedure are an efficient pre-processor for input generation, a multipoint constraint option to allow the user to exploit any existing symmetry in the problem, and a procedure for generating initial conditions from axisymmetric analyses. This procedure can be used to conduct parametric studies on loaded tires by using a rather coarse mesh and large load steps, thus leading to a significant reduction in CPU time, with a minimum sacrifice in solution accuracy. The efficiency of this procedure is illustrated with the analysis of a radial automobile tire.
Testing of Tire Treadwear under Laboratory and under Service Conditions
Authors: Ambelang J. C.
Published: June 2006

Four different laboratory machines for the evaluation of tire treadwear have been described which used concrete, steel, and tungsten carbide abrasion surfaces at variable speed and slip, but none has satisfactorily replaced highway testing. Predominant sources of wear on passenger tires appear to be cutting and frictional fatigue, the rates of which are influenced differently by temperature and load. Thus, seasonal or climatic, topographical, and geographical effects are evidenced. Treadwear cannot be expressed solely as a property of the tire since it is the resultant of the interaction of the tire with multivariate environmental conditions.
Rapid Tire Wear Measurements Using a Two-Wheeled Trailer
Authors: Southern E.
Published: June 2006

A method has been developed using a two-wheeled trailer to obtain accelerated wear data on tires. The method is much quicker than conventional testing, and the results on a test car show good agreement with trailer results. The rate of wear can usually be established to within 5 percent so that small differences between compounds are readily detected. Tests on multi-section tires have been carried out but are not found to be a satisfactory way of increasing reliability. Results are normally presented in the form of a wear rating relative to a control compound, and the data shows that reversals in ranking occur as the conditions of test are changed to cause variations in the tire surface temperature.
Finite Element Modeling of Tires on Snow
Authors: Shoop S. , Kestler K. , Haehnel R.
Published: June 2006

Vehicle movement on unpaved surfaces is important to military, agriculture, forestry, mining, construction, and recreation industries. Because of the complicated nature of vehicle-terrain interaction, comprehensive modeling of off-road mobility is often done using empirical algorithms. The desire to incorporate more physics into performance models has generated great interest in applying numerical modeling techniques in a full three-dimensional analysis, accounting for the deformation of both the tire and the terrain. In this study, a three-dimensional finite element model was constructed to simulate a tire rolling over snow. The snow was modeled as an inelastic material using critical-state constitutive modeling and plasticity theory. The snow material model was generated from experiments on the mechanical deformation of snow and was validated using a plate sinkage test. The tire models represent a range of sizes accommodating light-truck and off-road military vehicles and were rolled on snow of various depths. The combined tire-terrain models were validated using force measurements collected with instrumented vehicles and with measured snow deformation. The model results were also compared to vehicle mobility predictions made using the winter algorithms of the NATO Reference Mobility Model. These comparisons illustrate the agreement between the finite element models and field measurements of motion resistance forces and snow deformation under the tire.
Pavement Damage Due to Conventional and New Generation of Wide-Base Super Single Tires
Authors: Al-Qadi I. L. , Elseifi M. A. , Yoo P. J. , Janajreh I.
Published: June 2006

The objective of this study was to quantify pavement damage due to a conventional (385/65R22.5) and a new generation of wide-base (445/50R22.5) tires using three-dimensional (3D) finite element (FE) analysis. The investigated new generation of wide-base tires has wider treads and greater load-carrying capacity than the conventional wide-base tire. In addition, the contact patch is less sensitive to loading and is especially designed to operate at 690kPa inflation pressure at 121km/hr speed for full load of 151kN tandem axle. The developed FE models simulated the tread sizes and applicable contact pressure for each tread and utilized laboratory-measured pavement material properties. In addition, the models were calibrated and properly validated using field-measured stresses and strains. Comparison was established between the two wide-base tire types and the dual-tire assembly. Results indicated that the 445/50R22.5 wide-base tire would cause more fatigue damage, approximately the same rutting damage and less surface-initiated top-down cracking than the conventional dual-tire assembly. On the other hand, the conventional 385/65R22.5 wide-base tire, which was introduced more than two decades ago, caused the most damage.
An Advanced Shell Theory Based Tire Model
Authors: Bozdog D. , Olson W. W.
Published: June 2006

The objective of this paper is to investigate a class of general tire models that provides results suitable for usage in vehicle dynamics. Tire models currently used for vehicle dynamic analyses are overly simplistic (springs, a spring and damper combination or semi-elastic substance) or based on curve fits of experimental data. In contrast, the tire models used by major tire companies are extremely complex with solutions possible only by finite element analysis. Between these two extremes exists the potential for an elasticity based shell theory tire model. Micro-mechanics and composite laminate theories provide an integrated approach to the macroscopic behavior of the tire carcass and the tread support plies. This methodology has the capability of including centrifugal and friction forces. Finite difference methods are applied that produce reliable and accurate solutions of the tire response.
A Simple Method of Handling Thermomechanical Coupling for Temperature Computation in a Rolling Tire
Authors: Futamura S. , Goldstein A.
Published: June 2006

The thermomechanical analysis of a pneumatic tire is a highly complex process due to the effects of temperature on both the mechanical state and the viscoelastic energy dissipation in the tire. This coupled thermomechanical behavior typically requires that rolling tire temperatures be determined iteratively. As a result, a steady-state analysis involves updating the temperature dependent elastic and viscoelastic properties as the solution proceeds. The process is further complicated in a non-steady-state analysis where material properties need to be updated at multiple intervals in time.

A simplified method is proposed. First, the sensitivity of the tire elastic response of the tire to changes in material stiffness is characterized using the “deformation index”. Then, using a commercial finite element program and an appropriate user subroutine, heat generation is expressed as a function of the local temperature using a simple algebraic expression involving the temperature dependent material properties and the deformation indices. Temperatures are computed using the finite element program with the coupling information contained in the user subroutine. The result is a simplified method for a fully coupled thermomechanical analysis of a tire for steady-state and transient thermal analysis. The accuracy and the simplicity of the method are demonstrated using a small “tire-like” model. The simplified method is compared to the fully coupled iterative method for a steady-state thermal solution.
Numerical Prediction of Car Tire Wear
Authors: Lupker H. , Cheli F. , Braghin F. , Gelosa E. , Keckman A.
Published: June 2006

Due to their many economic and ecological implications, the possibility to predict tire wear is of major importance to tire manufacturers, fleet owners and governments. Based on these observations, in 2000, a three-year project named TROWS (Tire and Road Wear and Slip assessment) was started. One of the TROWS objectives is to provide a tool able to numerically predict tire global wear as well as to qualitatively determine the wear distribution. The proposed methodology combines a mathematical model of the tire with an experimentally determined local friction and wear law. Thus, tire abrasion due to each single maneuver can be determined.

Full-scale experimental tests were carried out with two Peugeot 406 cars on a public road course in Italy. Each car was equipped with a different set of tires: one car was equipped with four all-season tires (from now on called A tires) and the other car was equipped with four winter tires (from now on called B tires). Both sets of tires had a 195/65 R15 size. The collected data was used to validate the model. The methodology proved to give qualitatively good tire wear predictions.
Tire Modeling Methodology with the Explicit Finite Element Code LS-DYNA
Authors: Hall W. , Mottram J. T. , Jones R. P.
Published: June 2006

A finite element modeling methodology capable of predicting the transient behavior inside of a rolling car tire is presented. Although the approach has been specifically developed using the explicit finite element code LS-DYNA, it will be suitable for other commercial codes. Attention is given to the role played in the model development by the computational resource, the mesh requirements, the constitutive material relationships, and the contact and friction phenomena. Two different radial tire models are described based on analysis of an experimental car tire from Dunlop Tyres Ltd., UK. The first model was developed for static loading and its results are favorably compared with data determined by full-scale physical testing. The methodology is developed further in the second model so that a simulation can cope with the rolling situation. Measured stresses at the contact patch are used to show that the rolling tire model predicts the dynamic response with a reasonable degree of accuracy.
Self‐organisation and the structural dynamics of plants
Authors: Weinstock Michael
Published: June 2006

Classical engineering is driven by efficiency, with a precise economy of materials and structures for specific conditions. Michael Weinstock explains how, conversely, biology has evolved redundancy as a deep strategy, with hierarchical arrangements of cells and tissues producing sufficient excess capacity for adaptation to changing environmental stresses. He explains how, with the assistance of George Jeronimidis and Nikolaos Stathopoulos, the Emtech masters programme at the Architectural Association (aa) has explored the integrated morphologies of plants, an analysis that reveals new models for engineered structures. Copyright © 2006 John Wiley & Sons, Ltd.
Manufacturing diversity
Authors: Menges Achim
Published: June 2006

Recent developments of digital fabrication and computer‐aided manufacturing (cam) in the building sector have a profound impact on architecture as a material practice. In this article, Achim Menges describes advanced processes of steel, timber and membrane fabrication and construction through an investigation of the pioneering work of world‐leading manufacturing companies Covertex, Finnforest Merk, Octatube Space Structures, Seele and Skyspan. Copyright © 2006 John Wiley & Sons, Ltd.
Material and digital design synthesis
Authors: Hensel Michael , Menges Achim
Published: June 2006

The advanced material and morphogenetic digital design techniques and technologies presented in this journal call for a higher level methodological integration, which poses a major challenge for the next generation of multidisciplinary architectural research and projects. This collaborative task encompasses the striving for an integrated set of design methods, generative and analytical tools and enabling technologies that facilitate and instrumentalise evolutionary design, and evaluation of differentiated material systems towards a highly performative and sustainable built environment. Michael Hensel and Achim Menges describe recent progress towards a higher‐level design synthesis of material self‐organisation, digital morphogenesis, associative parametric modelling and computer‐aided manufacturing (cam) on the basis of two works produced within the context of the Emergent Technologies and Design Masters programme at the Architectural Association in London, and a recent competition entry by Scheffler + Partner Architects and Achim Menges. Copyright © 2006 John Wiley & Sons, Ltd.
Dirk Cove
Authors: Melvin Jeremy
Published: June 2006

Jeremy Melvin describes how for Niall McLaughlin the remodelling of a coastguard's cottage, in a dramatic coastal setting in County Cork, offered a unique opportunity to render ‘nature into ephemeral space’. Copyright © 2006 John Wiley & Sons, Ltd.
Clarion Quay
Authors: Payne Robert
Published: June 2006

A high‐rise housing scheme in Dublin that disperses affordable units in the same blocks as privately owned apartments, Clarion Quay was planned as a key piece in the city's docklands regeneration. As Robert Payne describes, the architects, Urban Projects, chose to elevate the high‐rise as a ‘heroic’ and ‘expressive’ form rather than turning their backs on the building type's Modernist past. Copyright © 2006 John Wiley & Sons, Ltd.
Metrogramma
Authors: Prestinenza Puglisi Luigi
Published: June 2006

Luigi Prestinenza Puglisi describes how the two principals of Metrogramma, an emerging office in Milan, drew on their postgraduate experiences in New York and the Netherlands to inform the dynamic manner in which they practise. Building up their practice through strategic urban planning, they are now setting their sights on major architectural schemes. Copyright © 2006 John Wiley & Sons, Ltd.
A New Generation of Catalytic Poly(vinylidene fluoride) Membranes: Coupling Plasma Treatment with Chemical Immobilization of Tungsten‐Based Catalysts
Authors: Lopez L. C. , Buonomenna M. G. , Fontananova E. , Iacoviello G. , Drioli E. , d'Agostino R. , Favia P.
Published: June 2006

A new generation of catalytically active membranes for secondary amine oxidation and phenol degradation has been developed by coupling the advantages of low‐temperature plasma‐modification processes with surface chemical immobilization reactions of catalysts. Poly(vinylidene fluoride) membranes have been modified with NH3 radiofrequency glow discharges in order to graft amino groups at their surface, providing active sites for stable immobilization of tungsten‐based heterogeneous catalysts. Particular attention has been focused on tungstate, WO42–, and decatungstate, W10O324–, which act efficiently as catalysts for the oxidation of secondary amines and as photocatalysts for the degradation of organic pollutants, respectively. Plasma‐modified membranes surface‐tailored with WO42– have been used in catalytic membrane reactors to activate hydrogen peroxide for oxidizing secondary amines to nitrones; membranes modified with W10O324– have been used for the complete degradation of phenol. The obtained results, in terms of amine–nitrone conversion and phenol degradation, respectively, appear extremely promising; these modified membranes can be considered as a pioneering, successful example of heterogenization of W‐based catalysts on plasma‐treated membranes.
Polyacrylonitrile Nanofibers: Formation Mechanism and Applications as a Photoluminescent Material and Carbon‐Nanofiber Precursor
Authors: Jang J. , Bae J. , Park E.
Published: June 2006

The facile synthesis of polyacrylonitrile (PAN) nanofibers is achieved using a microemulsion polymerization. The detailed formation mechanism of polymer nanofibers is examined using electron microscopy and UV‐vis and Fourier transform infrared spectroscopies, and the optoelectronic properties are studied by confocal laser scanning microscopy. The effects of surfactant properties, such as concentration, chain length, and ionic character, as well as monomer structure and polymerization temperature, on the structure of the resulting polymer nanofibers are also investigated extensively. Importantly, PAN nanofibers exhibited novel photoluminescence (PL), which is observed for the first time. The PL of PAN nanofibers is significantly different from that of PAN nanoparticles. The PAN nanofibers are also used as a precursor for carbon nanofibers. The carbonization temperature has a dominant effect on the degree of crystallinity of the resulting carbon nanofibers. This study is the first demonstration of the fabrication of polymer and carbon nanofibers using a convenient polymerization technique.
Amorphous Carbon Nanotubes with Tunable Properties via Template Wetting
Authors: Chen J.‐T. , Shin K. , Leiston‐Belanger J. M. , Zhang M. , Russell T. P.
Published: June 2006

Amorphous carbon nanotubes have been prepared by casting thin films of polyacrylonitrile (PAN) and polystyrene‐block‐polyacrylonitrile (PS‐b‐PAN) within a porous anodic aluminum oxide (AAO) membrane followed by pyrolysis. Raman and wide‐ angle X‐ray diffraction (WAXD) measurements indicate that the carbon nanotubes are of low crystallinity. The thickness of the carbon nanotube walls is controlled by either changing the concentration of the precursor solution or by using multiple casting and pyrolysis steps. When diblock copolymers of PS‐b‐PAN are used, it is found that nanopores are created within the nanotube walls after pyrolysis. The carbon nanotubes can be used to create carbon coated nanorods of polystyrene‐block‐polybutadiene (PS‐b‐PBD).
Novel nickel (II) complexes chelating β‐diketiminate ligands: synthesis and simultaneous polymerization and oligomerization of ethylene
Authors: Li Yongfei , Wang Lingyun , Gao Haiyang , Zhu Fangming , Wu Qing
Published: June 2006

Two novel nickel (II) complexes, CH{C(CF3)NAr}2NiBr (1, Ar = 2,6‐iPr2C6H3 and 2, 2,6‐Me2C6H3), were synthesized by the reaction of the lithium salt of fluorinated β‐diketiminate backbone ligands with (1,2‐dimethoxyethane) nickel (II) bromide [(DME)NiBr2]. The solid‐state structure of nickel (II) complex 2 as a dimer reveals four‐coordination and a tetrahedral geometry with bromide bridged by single crystal X‐ray measurement. Both complexes catalyze simultaneous polymerization and oligomerization of ethylene when activated by methylaluminoxane (MAO). It was found that the reaction temperature has a pronounced effect on the activity of ethylene polymerization and the molecular weight of obtained polyethylene. In addition, the nickel catalytic systems predominantly produce linear polyethylene with unsaturated end groups. Copyright © 2006 John Wiley & Sons, Ltd.
Management of septic groin complications and infected femoral false aneurysms in intravenous drug abusers
Authors: Chan Y C , Burnand K G
Published: June 2006

Arterial reconstruction not required
A skinning approach for dynamic 3D mesh compression
Authors: Mamou Khaled , Zaharia Titus , Prêteux Françoise
Published: June 2006

This paper proposes a novel approach for 3D mesh compression, based on a skinning animation technique. The core of the proposed method is a piecewise affine predictor coupled with a skinning model and a DCT representation of the residuals errors. The experimental evaluation shows that the proposed skinning‐based encoder outperforms (with bitrates gains from 47% to 67%) GV, RT, MPEG‐4/AFX‐IC, D3DMC, PCA and Dynapack techniques. Copyright © 2006 John Wiley & Sons, Ltd.
Minimal dynamic modeling for dance verbs
Authors: Hsieh Chi‐Min , Luciani Annie
Published: June 2006

As quoting in the philosophy of free dance: ‘understanding the directions for a free dance performer stems mainly from the qualities and energy of the movement rather from spatial criteria,’ we advocate generating computing dance movement by dynamic and energy. In this paper, we present a set of dynamic models according to dance verbs: ‘to sway,’ ‘to squat down,’ ‘to develop,’ ‘to walk,’ ‘to turn,’ and ‘half turn step over step.’ For each of them, we designed the simplest physically based particle model. Among them, user has a high‐level motion control to modify the quality of such dynamically generated movement, for example, light, strong, sudden, sustained, etc. These dynamic models are hence well suited to produce spontaneous motion that looks natural and plausible. Furthermore, by designing dance movement only with the necessary minimal models, it is possible to produce complex dance movement that exhibits energetic consistency as underlain by the philosophy of free dance. Copyright © 2006 John Wiley & Sons, Ltd.
Facial actions as visual cues for personality
Authors: Arya Ali , Jefferies Lisa N. , Enns James T. , DiPaola Steve
Published: June 2006

What visual cues do human viewers use to assign personality characteristics to animated characters? While most facial animation systems associate facial actions to limited emotional states or speech content, the present paper explores the above question by relating the perception of personality to a wide variety of facial actions (e.g., head tilting/turning, and eyebrow raising) and emotional expressions (e.g., smiles and frowns). Animated characters exhibiting these actions and expressions were presented to human viewers in brief videos. Human viewers rated the personalities of these characters using a well‐standardized adjective rating system borrowed from the psychological literature. These personality descriptors are organized in a multidimensional space that is based on the orthogonal dimensions of desire for affiliation and displays of social dominance. The main result of the personality rating data was that human viewers associated individual facial actions and emotional expressions with specific personality characteristics very reliably. In particular, dynamic facial actions such as head tilting and gaze aversion tended to spread ratings along the dominance dimension, whereas facial expressions of contempt and smiling tended to spread ratings along the affiliation dimension. Furthermore, increasing the frequency and intensity of the head actions increased the perceived social dominance of the characters. We interpret these results as pointing to a reliable link between animated facial actions/expressions and the personality attributions they evoke in human viewers. The paper shows how these findings are used in our facial animation system to create perceptually valid personality profiles based on dominance and affiliation as two parameters that control the facial actions of autonomous animated characters. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and Structures of Se Analogues of the Antithyroid Drug 6‐n‐Propyl‐2‐thiouracil and Its Alkyl Derivatives: Formation of Dimeric Se–Se Compounds and Deselenation Reactions of Charge‐Transfer Adducts of Diiodine
Authors: Antoniadis Constantinos D. , Hadjikakou Sotiris K. , Hadjiliadis Nick , Papakyriakou Athanasios , Baril Martin , Butler Ian S.
Published: June 2006

Four selenium analogues of the antithyroid drug 6‐n‐propyl‐2‐thiouracil (PTU), of formulae RSeU, (R = methyl (Me) (1), ethyl (Et) (2), n‐propyl (nPr) (3), and isopropyl (iPr) 4), have been synthesized. Reaction of 1–4 with diiodine in a 1:1 molar ratio in dichloromethane results in the formation of [(RSeU)I2] (R = methyl (5), ethyl (6), n‐propyl (7) and isopropyl (8)). All compounds have been characterized by elemental analysis, FT‐Raman, FT‐IR, UV/Vis, 1H–, 13C–, 77Se–1D and ‐2D NMR spectroscopy, and ESI‐MS spectrometric techniques. Recrystallization of 4 from dichloromethane afforded (4⋅CH2Cl2). Crystals of [(nPrSeU)I2] (7), a charge‐transfer complex, were obtained from chloroform solutions, while crystallization of 6 and 7 from acetone afforded the diselenides [N‐(6‐Et‐4‐pyrimidone)(6‐EtSeU)2] (9⋅2 H2O) and [N‐(6‐nPr‐4‐pyrimidone)(6‐nPrSeU)2] (10) as oxidation products. Recrystallization of 7 from methanol/acetonitrile solutions led to deselenation with the formation of 6‐n‐propyl‐2‐uracil (nPrU) (11). [(nPrSeU)I2] (7) was found to be a charge‐transfer complex with a SeI bond. These results are discussed in relation to the mechanism of action of antithyroid drugs.
Metal Directed Assemblies of a Dipeptide: Formation of β‐Pleated Sheets
Authors: Barooah Nilotpal , Sarma Rupam J. , Baruah Jubaraj B.
Published: June 2006

The crystal structure of N‐phthaloylglycylglycine and its complexes with copper(II) and zinc(II) are studied. The N‐phthaloylglycylglycinato copper(II) complex has a polymeric structure formed by bridging carboxylates. The corresponding N‐phthaloylglycylglycinato zinc(II) complex is monomeric. Both the metal complexes have self‐assembled hydrogen‐bonded structures in which dipeptide ligand adopt β‐pleated conformations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Dramatic Effects of Ionic Liquid on Platinum Electrode Surface and Electron‐Transfer Rates of meso‐Tetraphenylporphyrins
Authors: Safavi Afsaneh , Movahedi Zarangiz , Mohajer Daryush , Maleki Norouz
Published: June 2006

The effect of addition of a room temperature ionic liquid, 1‐butyl‐3‐methyl imidazolium hexafluorophosphate [bmim][PF6], on the electrochemical behavior of different free‐base para‐substituted meso‐tetraphenylporphyrins in dichloromethane solution has been studied using cyclic voltammetric technique. It has been found that the ionic liquid has the ability to regenerate platinum electrode surface and improves the reversibility of electrode processes. This has been true for the case of all the porphyrins studied.
Determination of optimum processing conditions for hot‐air roasting of hulled sesame seeds using response surface methodology
Authors: Kahyaoglu Talip , Kaya Sevim
Published: June 2006

Sesame paste (tahin) is produced by milling hulled, roasted, sesame seeds. In this study, a hot‐air roasting process for the production of sesame paste was optimised by response surface methodology (RSM) over a range of air temperatures (120–180 °C) for various times (30–60 min). The colour parameters (L, a and b values), browning index (BI), hardness, fracturability and moisture content of the seeds were used as response parameters to develop predictive models and optimise the roasting process. Increases in roasting temperature and time caused increases in the a and b values and in the BI. The hardness and fracturability of seeds also decreased with increasing roasting temperature and time. The quadratic and linear models developed by RSM adequately described the changes in the colour values and textural parameters, respectively. The result of RSM analysis showed that all colour parameters and textural parameters should be used to monitor the roasting of sesame seeds in a hot‐air roaster. To obtain the desired colour and texture, the optimum roasting range for production of sesame paste was determined as 155–170 °C for 40–60 min. Copyright © 2006 Society of Chemical Industry
Abdominal muscle size and symmetry in normal subjects
Authors: Rankin Gabrielle , Stokes Maria , Newham Dianne J.
Published: June 2006

This study was undertaken to establish normal reference ranges for abdominal muscle size and symmetry and to examine the effects on these of gender and age. We studied 123 subjects, consisting of 55 men (aged 21–72 years) and 68 women (aged 20–64 years). Real‐time ultrasound imaging of the abdominal muscles was performed. Thickness of internal and external oblique (IO, EO), transversus abdominis (TA), and rectus abdominis (RA), and cross‐sectional area (CSA) of RA were measured, and absolute and relative muscle thickness (percent total muscle thickness), order of thickness, and symmetry (percent difference between sides) were determined. Males had significantly larger muscles than females and size was poorly correlated with age. The pattern of relative muscle thickness was RA > IO > EO > TA. Symmetry for total absolute thickness of all three lateral muscles was 8%–9% (mean) but for individual muscles there was asymmetry of absolute size (13%–24%), whereas relative thickness was symmetrical for all muscles. These findings provide robust reference data for the abdominal muscles in normal males and females in order to enable comparison with clinical groups to assess abnormalities and establish sensitivity for evaluating the effectiveness of interventions. Muscle Nerve, 2006
Nonprofits and social capital: Measurement through organizational surveys
Authors: Passey Andrew , Lyons Mark
Published: June 2006

Nonprofit organizations are said to play important roles in the reproduction of social capital, although research suggests that some types of nonprofits add more to stocks of social capital than others and that they vary in the types of social capital they reproduce. Such findings typically come from surveys of individuals or households, as opposed to surveys of nonprofits themselves. In this research article, we draw on a survey of a sample of Australian nonprofit organizations to demonstrate a method of empirically testing some of the ways that nonprofit organizations are said to reproduce social capital and to assess differences in any contributions by important organizational characteristics such as industry or primary beneficiary. We aim to show how surveys of organizations might add to our understanding of the contribution of nonprofits to stocks of social capital.
Antiviral activity and constituent of Ardisia chinensis benth against coxsackie B3 virus
Authors: Su Miaoxian , Li Yaolan , Leung Kam Tong , Cen Yingzhou , Li Ting , Chen Runzhi , Ooi Vincent E. C.
Published: June 2006

Ardisia chinensis Benth is a medicinal plant traditionally used in the area of Yao minority in Southern China. The in vitro antiviral activities of extracts and fractions from Ardisia chinensis were tested by the cytopathic effect (CPE) reduction assay in the present study. As a result, both the aqueous extract and the 95% ethanol extract of Ardisia chinensis showed in vitro antiviral activity against Coxsackie B3 (Cox B3) virus to different extents, and the aqueous extract possessed more potent activity than the ethanol extract. Bioassay‐guided fractionation revealed that the antiviral activity of Ardisia chinensis was attributed mainly to its high polar fractions, and finally identified to be a polysaccharide. The Ardisia chinensis polysaccharide (ACP) fractionated from the aqueous extract exhibited a significant antiviral effect against Cox B3 with a 50% inhibitory concentration (IC50) of 3.9 µg/mL and a selective index (SI) over 256. Preliminary characterization indicated that ACP is a neutral polysaccharide in which d‐glucose is the major component. The average molecular weights of ACP were determined to be 40037 Da (Mw), 28297 Da (Mn) and 33758 Da (Mp) by gel permeation chromatography. Copyright © 2006 John Wiley & Sons, Ltd.
Protecting Sexual Minority Youth from Research Risks: Conflicting Perspectives
Authors: Miller Robin Lin , Forte Draco , Wilson Bianca Della Marie , Greene George J.
Published: June 2006

We describe the dilemmas we encountered in the informed consent process for an HIV prevention project targeting Black gay, bisexual, and non‐gay identified young men. We highlight the complexities of applying informed parental consent procedures to sexual minority youth and identify some of the challenges that researchers who work with sexual minority youth face when they must balance the needs and rights of this population against the needs and rights accorded to parents by federal guidelines for protecting minor participants in research.
The reciprocal risks of stroke and cognitive impairment in an elderly population
Authors: Jin Ya‐Ping , Di Legge Silvia , Ostbye Truls , Feightner John W. , Hachinski Vladimir
Published: June 2006

Background

Stroke, dementia, and cognitive impairment no dementia (CIND) pose major threats to the elderly but have rarely been studied together in the same population. We aimed to compare the relative frequencies of stroke, CIND, and dementia in an elderly population and to examine whether cognitive impairment poses a risk for stroke.

Methods

Prevalences of stroke, CIND, and dementia were estimated among participants in the first clinical examination of the Canadian Study of Health and Aging (CSHA‐1, n = 2,914). Incidence rates were determined at the 5‐year follow‐up (CSHA‐2) among those cognitively normal and stroke free at CSHA‐1 (n = 828). The associations between cognitive impairment and stroke were assessed by Cox regression analyses.

Results

Among elderly Canadians, the age‐standardized prevalence of stroke, CIND, and dementia were 8%, 17%, and 8%, respectively. Alone or combined, they affected one fourth of the elderly. Among stroke survivors, 64% had cognitive impairment compared with 21% among stroke‐free persons. Among the cognitively impaired, 25% had a stroke compared with 4% among the cognitively normal. The incidence rates of stroke, CIND, and dementia were 3, 6, and 3 per 100 person‐years, respectively. Compared with cognitively normal subjects, the adjusted risk for incident stroke was 1.3 (95% confidence interval [CI], 0.9 to1.9) in patients with CIND and 2.3 (95% CI, 1.7 to 3.2) in patients with dementia regardless of whether “questionable stroke” was included.

Conclusions

Stroke and cognitive impairment pose risk for each other. CIND is highly prevalent, and some of its subtypes may represent treatable preludes to stroke and/or dementia.
Perspectives on assessing benefits and risks in clinical trials for Alzheimer's disease
Authors: McConnell Stephen , Karlawish Jason , Vellas Bruno , DeKosky Steven
Published: June 2006

Balancing benefits and risks in the development of treatments for Alzheimer's disease is challenging given the nature of the disease but critically important to ensure effective treatments are available. Drawing on a diverse panel of scientists, regulators, caregivers, patients and advocates convened by the Alzheimer's Association, insights are offered into benefit/risk assessment, decision‐making, regulatory and societal factors affecting clinical trials on AD. Several policy solutions are offered to improve the drug testing, review and approval process.
Telemedicine, dementia and Down syndrome: Implications for Alzheimer disease
Authors: Lott Ira T. , Doran Eric , Walsh David M. , Hill Mary Ann
Published: June 2006

Background

Individuals with Down syndrome (DS) who are at risk for dementia of the Alzheimer type (DAT) often live at sites remote from major medical centers. Telemedicine (TM) is a modality for providing medical care at remote locations but is underutilized for populations with Alzheimer disease (AD).

Methods

We studied the feasibility of using TM to evaluate symptoms of DAT in 90 individuals with DS. Dementia was assessed by an informant questionnaire, a direct measure of praxis, pathological reflexes on the neurologic examination, and the presence of cortical atrophy on a neuroimaging procedure. The neurologist was blinded to the scores on neuropsychological measures. Differences in average cognitive scores between a TM and traditional academic medical center–based clinic site (TAC) were tested using 2‐way analysis variance with site and premorbid IQ as factors. Logistic regression was used to explore the relationship, in addition to the cognitive scores, of influences such as age, premorbid IQ, and site to the prediction of the physician's diagnosis of dementia.

Results

Components of the neurologic, imaging, and neuropsychological examinations differentiated subjects with and without DAT (p≤0.008) irrespective of whether a subject was evaluated at a TM or TAC site.

Conclusions

It is feasible to make a diagnosis of DAT in DS by TM. This study supports the need for formal reliability and validity studies of TM preparatory to the consideration of this modality for use in clinical trials for AD.
Participation and support for the constitution in Uganda
Authors: Moehler Devra C.
Published: June 2006

A major challenge for transitioning states is to create a constituency of citizens to support and defend the new constitution. Participatory constitution-making is one of the most often recommended methods for enhancing constitutional legitimacy. This research tests the claim that public participation in the Ugandan constitution-making process built support for the 1995 constitution. Contrary to expectations, multivariate analysis of survey data demonstrates that citizens who were active in the process were no more supportive of the constitution than those who stayed at home. In-depth interviews reveal that local political leaders, not participation, caused citizens to view the constitution as legitimate or illegitimate. Constitutions are difficult for citizens to evaluate, so they rely on political elites for information and opinions. To predict whether participation will strengthen or weaken constitutional support, we must examine the messages that elites communicate to citizens about their participation, the process, and the resulting constitution.
Census of Brazilian Merganser Mergus octosetaceus in the region of Serra da Canastra National Park, Brazil, with discussion of its threats and conservation
Authors: LAMAS IVANA REIS
Published: June 2006

The biggest and best-known population of Brazilian Merganser Mergus octosetaceus occurs in the region of Serra da Canastra National Park, Minas Gerais, Brazil. However, prior to our study it had been recorded in only six sites in the park and its buffer zone. In 2001 and 2002 we surveyed the region to confirm the occurrence of the Brazilian Merganser in different areas within and outside the park. Samples were taken by walking along the banks of the watercourses, using tape-recording playback. We sampled 49 stretches of streams, and observed Brazilian Mergansers in nine localities, totalling 29 sightings. Taking into consideration the reports by biologists who participated in the fieldwork for the review of the park's management plan, the guaranteed reports of the occurrence of the species from local people, and the sites where its occurrence is judged to be very likely, we believe there are at least 81 individuals in the areas sampled. We point out that the absence of records in an area does not mean the absence of the species. Indeed, the presence of the Brazilian Merganser was confirmed, after the end of our field studies, in some stretches where we indicated its occurrence as very likely but had failed to detect it during the sampling. All anthropogenic activities that influence the quality and integrity of the rivers and their banks are a potential threat to Mergus octosetaceus. Efforts to preserve the species entail the conservation of its habitats, which comprise important watercourses and the surrounding natural vegetation.
Mg/Ca ratios in the planktonic foraminifer Neogloboquadrina pachyderma (sinistral) in the northern North Atlantic/Nordic Seas
Authors: Meland Marius Y. , Jansen Eystein , Elderfield Henry , Dokken Trond M. , Olsen Are , Bellerby Richard G. J.
Published: June 2006

In core top samples in the Nordic Seas, Mg/Ca ratios of N. pachyderma (sin.) are generally consistent with previous high‐latitude calibration data but do not reflect the modern calcification temperature gradient from 2°C in the northwest to 8°C in the southeast. This is because Mg/Ca ratios in foraminiferal shells from the central Nordic Seas are ∼0.4 mmol/mol higher than expected from calibrations of Nürnberg (1995) and Elderfield and Ganssen (2000). The enhanced Mg/Ca ratios are observed in an area with low sedimentation rates (<∼5 cm/kyr). Possible factors that may cause this include bioturbation, Holocene variability in old core tops, dissolution, pore water chemistry, occurrence of volcanic ash, and other natural variability. The enhanced foraminiferal Mg/Ca ratios in areas of the Nordic Seas and the northern North Atlantic may also be linked with secondary factors related to the presence of fresher and colder water masses, possibly combined with pore water chemistry in low‐sedimentation areas differing from high‐sedimentation areas.