bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Physic Modeling and Simulation Optimization of Hydraulic Support Tester Loading System
Authors: Wang Xiang Wei , Chen Yong Liang , Han Y.
Published: September 2011

Hydraulic support tester is the key equipment to measure the safety performance and technical performance of the hydraulic support. As an integral part of hydraulic support tester, synchronized loading system bears much load and eccentric load, needs high synchronization precision, and exits mechanical-hydraulic coupling. For these characteristics, building a synchronous loading system platform model, carrying on force analysis of the platform, and then getting four-cylinder pressure at different heights of the loading course are necessary. This research constructs a synchronous control circuit for hydraulic loading system using multi-physic modeling and simulation software—AMESim; simulation is carried out to optimize parameters of PID controllers in order to reduce the four-cylinder position synchronization error. As a conclusion, simulation results validate that appropriate solutions improve the precision and also demonstrate that the designed control system is suit for the synchronization control of the four-cylinder.
Dynamics of the Gear Train Set in Wind Turbine
Authors: Ji D.D. , Song Y.M. , Zhang J.
Published: September 2011

A lumped-parameter dynamic model for gear train set in wind turbine is proposed to investigate the dynamics of the speed-increasing gear box. The proposed model is developed in a universal Cartesian coordinate, which includes transversal and torsional deflections of each component, time-varying mesh stiffness, gear profile errors and external excitations. By solving the dynamic model, a modal analysis is performed. The results indicate that the modal properties of the multi-stage gear train in wind turbine are similar to those of a single-stage planetary gear set. A harmonic balance method (HBM) is used to obtain the dynamic responses of the gearing system. The responses give insight into the impact of excitations on the vibrations.
Finite Element Contact Analysis for Sprocket of an Armoured Face Conveyor
Authors: He B.Y. , Sun Y.H. , Li G.P. , Chen S. Z.
Published: September 2011

Sprocket has an important role in improving the transport performance and life of the armoured face conveyor, which is the key component in the transmission system of armoured face conveyor (AFC). In this paper, true stress-true strain curves of materials of the sprocket and the ring chain are obtained by computing the data of static tensile test. A simplified symmetric finite element contact model is established based on the nonlinear finite element software ABAQUS. Stress field and torsional stiffness coefficient of the sprocket are calculated according to loads and boundary conditions. Simulation results are in good accordance with the test results. The finite element model and the simulation results provide useful guidance for design and test of the sprocket. Meanwhile, accurate torsional stiffness coefficient of the sprocket is obtained for simulation of the transmission system of AFC.
Analysis of the Emotional Factors in Design Process
Authors: Su L.X. , Yang Zheng
Published: September 2011

Emotions are the important factors affecting design. The instant exquisite self-demand resulted from being emotional can provide creative sources for design, and it is the catalyst of the creativity. The designers often neglect their most basic emotional creativity. This paper analyzes the effect of emotions in design based on cultural emotions and individual emotions, and proposes reasonable advices for emotional management in design process.
Through the "Cottage" Prospects of Chinese Design
Authors: Huang J. , Yang Zheng
Published: September 2011

With the recent years, the rise of cottage, as a projection of the different forces, takes advantage of the current main market of electronic products in China with the characteristics of strong imitation, rapid production and civilian population, moreover,it shows a low-input high return phenomenon.Cottage that mainly actives in the Guangdong area has the trend to expand inland, it does not have their own brand, and mainly imitates the well-known brands of electronic products to thrive.It stimulus the design from the negative aspect,and wants to reverse the design of stagnation with distorted position.Its' rise means that China is undergoing a qualitative change in the design and further affecting the development of the design industry,which would lead the design into a new industry.
Grinding Capability of the Indigenous Polymer-Based Solid Lubricant Coating Wheels Used in Dry Grinding
Authors: Ding L.Y. , Su Hong Hua , Xu H.J. , Fan M.
Published: September 2011

It is essential to control the heat generated in the cutting zone in order to ensure the workpiece quality after grinding. This article deals with an investigation in using graphite and hexagonal boron nitride as solid lubricants to reduce friction and thereby improve the surface integrity of Ti-6Al-4V alloy. The polymer-based solid lubricant coating wheels have been prepared. Grinding experiments have been conducted to study the effect of the graphite and hexagonal boron nitride lubricants on the grinding temperature and the surface quality of the workpiece while grinding Ti-6Al-4V. Results indicate that there is a considerable improvement in the performance of grinding Ti-6Al-4V using graphite and hexagonal boron nitride as solid lubricants in dry grinding in terms of grinding temperature and surface quality of the work piece. The indigenous polymer-based solid lubricant coatings are effective in dry grinding.
Characterization of a MEMS Accelerometer Considering Environmental Temperature Fluctuations
Authors: Liu Guang Jun , Jiang T. , Jiang Q.K. , Wang A.L.
Published: September 2011

This paper investigates the effects of environmental temperature fluctuations on the performance of a MEMS accelerometer. The model, vibration equation, and calculation of the output of detection capacitance for the accelerometer are presented. The fluctuations in temperature are considered when evaluating the actual performance of the device. The analysis results show that temperature fluctuations have a great influence on the output of the accelerometer although it has little influence on the resonant frequency of sensing mode and the sensitivity of detection capacitance. The performance deviations under the effects of temperature fluctuations are calculated accurately, which provides a reference for the design of temperature compensation method and robust design for the accelerometer.
Driver Design of the Piezoelectric Ultrasonic Transducer for Wire Bonding Based on Direct Digital Synthesis Technology
Authors: Zhang Hong Jie , Wang Fu Jun , Hou Y.Y. , Zhang D.W.
Published: September 2011

In order to design a driver of piezoelectric ultrasonic transducer which can provide high quality ultrasonic signal and be able to realize the frequency tracking rapidly, accurately and intelligently during the bonding process, the ATmega128 microcontroller and AD9851 synthesizer are selected as core components to build an ultrasonic generator and frequency tracking system. The basic circuit units including low pass filter, power amplifier, signal detection and conversion circuits are also established. The test results of the system shows that, based on DDS technology, high quality ultrasonic signal for transducer can be achieved. By combining the two kinds of frequency tracking methods, the system can realize the frequency tracking during the bonding process. It also indicates that the design significantly improve the precision and flexibility of the ultrasonic generator system.
A Design of Parallel High Frequency Dynamometer Fixture
Authors: Wu H. , Li Liang , He N.
Published: September 2011

Micro milling force is the main parameter in motoring dynamic cutting process. The natural frequency of dynamometer is the key factor in the accurate measurement of high speed milling force. In this paper, a new structure fixture is designed, and the natural frequency of the fixture is obtained by finite element methods. After optimizing the structure design, the fixture is produced for the force signal acquisition system, together with the forces transducer, signal acquisition card and the software based on the LabVIEW. The experiment shows that the design of the fixture can meet the requirements of force acquisition.
Applications of Ultra-Precision Free-Form Machining Technology to Advanced Optics
Authors: Lee Wing Bun , Wang H. , To Suet , Cheung C.F.
Published: September 2011

Nowadays, the proliferation of commercial applications of consumer electronics and advanced optics has imposed extensive requirements on the fabrication of non-conventional geometries and free-form surfaces with stringent achievable tolerances and extremely high accuracy and surface roughness. This paper exhibits our successful applications of ultra-precision free-form machining technology to the production of a variety of advanced imaging and illumination optics.
Identification of Bolt Connection Parameters for Vertical Grinding Machine in CAD/CAE Environment
Authors: Wang Chao Hao , Chen Yong Liang , Pang Jin Ping , Zhang Da Wei , Pan G.X.
Published: September 2011

Dynamic analysis and modal test were conducted on a vertical grinding machine. The mathematical model of joint surface parameter identification between the bed and the column was established in CAD/CAE integrated environment. Based on the results of dynamic analysis and modal test, the parameters of joint surface were identified and the finite element model was accurately created. Then, the weak bodies of the original machine were improved. According to the finite element analysis of the improved machine, the performances of the new machine were better than the original machine.
Ultrasonic, Metallographic and Photo Acoustic Studies on Zircaloy-2
Authors: Palanichamy P. , Sivabharathy M. , Jeyadheepan K. , Kalyanasundaram P. , Ramachandran K. , Sanjeeviraja C.
Published: September 2011

The nuclear material, Zircaloy-2 is studied here by photoacoustics and the results are correlated with ultrasonic measurements and metallographic microstructures. Precipitation of hard intermetalics and formation of α-martensite, due to thermal aging are also explained through photoacoustic studies.
Effect of Annealing on Cold Worked D9 Alloy by Photoacoustics
Authors: Palanichamy P. , Sivabharathy M. , Jeyadheepan K. , Kalyanasundaram P. , Ramachandran K. , Sanjeeviraja C.
Published: September 2011

Alloy D9 is a candidate material for core components of fast breeder reactors. This alloy has been 20% cold worked and thermally aged at 1073 K for different time durations and their thermal properties have been studied using photoacoustic (PA) measurements. The results of the PA measurements have been correlated well with the ultrasonic velocity and hardness measurements.
Modelling the Diffusive Growth of Carbon Fullerenes
Authors: Bunder Judith E. , Hill James M.
Published: September 2011

Recently, the present authors proposed a model describing fullerene growth in carbonvapor for which the di usion equation is assumed outside the fullerene and a family of possibleStefan conditions describe the growing fullerene surface. Here we consider a related model, butwith the additional assumption that the fullerene surface atomic density is constant throughoutthe growth process, which is justi ed by experimental data. We show that this constraint onthe fullerene lattice structure limits the solution to one possible Stefan condition. The proposedmodel may be extended to any nanostructure with constant atomic surface density.
Single-Domain Ferroelectric Water and its Concerted Diffusion in Nanotubes
Authors: Nakamura Yoshimichi , Ohno Takahisa
Published: September 2011

The term ‘ferroelectric water’ has so far stood for ‘ferroelectric ice.’ In molecular dynamics simulations, we find that, counter to intuition, single-domain ferroelectric water is possible inside carbon nanotubes open to a liquid water reservoir. Though this water is tube-shaped, it is strikingly different in structure and dynamics from ‘ice nanotubes.’ A series of step-wise changes in net polarization of water and mobile/immobile water transitions are observed to occur spontaneously. This study not only improves our general knowledge of water, but is also suggestive of potential multifunctional capabilities of simple hydrophobic nanotubes for future applications.
Electrospun Nanofibres of PLA/PANI and PLA/P (ANI-co-m-ABA): Thermal Studies
Authors: Abdul Rahman Norizah , Easteal Allan J. , Travas-Sejdic Jadranka , Easteal Allan J.
Published: September 2011

Composite nanofibres of poly (lactic acid) (PLA) with polyaniline (PANI) or poly (aniline-co-m-aminobenzoic acid) (P (ANI-co-m-ABA)) were prepared by electrospinning. Thermal effects on the properties of the composite nanofibres were studied by means of DSC and TGA. TGA results show that the onset thermal degradation temperature of the composite fibres was slightly higher than that of pure PLA. The degree of the crystallinity of the nanofibres was determined from DSC data and compared to film with the same composition.
Arrays of Au Nanoparticles on Si Formed by Nanoindentation and a Simple Thermal/Wipe-Off Technique
Authors: Shalav Avi , Wong Sherman , Ruffell Simon , Elliman Robert G.
Published: September 2011

This study demonstrates a novel technique for the fabrication of ordered arrays of Au rich nanoparticles on a Si substrate. Si substrates, with their native oxides intact, are pre-patterned using nanoindentation to create regions on the surface that readily alloy at higher temperatures with a thin thermally evaporated Au layer. Larger Au rich particles are observed to form at the indentation sites after high temperature annealing in an inert atmosphere. After mechanical wiping, the Au rich particles lying within the indentation sites remain while almost all the particles on the native oxide surface are readily removed. Using PECVD techniques, multi-prong Si nanowires are shown to grow from the remaining arrays of Au rich particles.
Synthesis of a Tri Chromophore System for Electro-Optic Applications
Authors: Bhuiyan M. Delower H. , Kay Andrew J. , Gainsford Graeme J. , Williamson Rachel M.
Published: September 2011

The synthesis of a suite of compounds containing three chromophores coupled to a central nitrogen atom are reported. X-ray crystallographic data has been obtained for two of the compounds and this suggests that incorporation of these molecules into such a trichomophore bundle is a valid strategy for minimizing dipole-dipole interactions, and therefore aggregation in these compounds.
Trapping Single Cells: Comparison between Sandwiched Insulation with Back Contact (SIBC) and Planar Biochip
Authors: Ibrahim Siti Noorjannah , Murray Lynn , Evans John J. , Alkaisi Maan M.
Published: September 2011

AC electrokinetics is one of many methods used to move particles in microfluidic channels. This paper presents single cell trapping efficacy using dielectrophoresis (DEP) force of two biochip designs; a planar biochip and the new sandwiched-insulation with back contact (SIBC) biochip. The new biochip, is structured on a glass slide, consists of microelectrode arrays patterned on top of Nickel-Chromium (NiCr) and Gold (Au) layers. Prior to the microelectrode patterning, a back contact layer of NiCr and Au was coated with SU-8 2005. Then, the SU-8 2005 or the insulation layer was patterned with arrays of microcavities. In contrast, the planar biochip consists of 2 layers; an SU-8 2005 insulation layer and NiCr and Au metal layers constructed on a Silicon Nitride (Si3N4) substrate. The electric field intensity results simulated using Comsol v3.5a software indicated that DEP force generated from the SIBC biochip are greater than the planar biochip design. Results from experiment with polystyrene microbeads and Ishikawa cancer cells also showed that the SIBC biochip has higher trapping efficiency than the planar biochip. These promising results indicate that the SIBC biochip is capable of trapping single cells and can be used to facilitate studies on intracellular activities using surface the replicating technique known as the Bioimprint technique.
Magnetotransport Study of Electron Doping in Sr2FeMoO6
Authors: Stephen Jibu , Williams Grant V. M. , Ruck Benjamin J.
Published: September 2011

We report the results from magnetotransport measurements on polycrystalline Sr2-xLaxFeMoO6 samples at magnetic fields of up to 8 T. We observe a normal as well as an anomalous Hall effect. We find that there is a small decrease in the normal Hall coefficient for La doped samples.
SEM Characterisation of the Cellulose Material Treated with Polycarboxylic Acid and Zeolite Nanoparticles
Authors: Bischof Vukušić Sandra , Flinčec Grgac Sandra , Katović Drago , Katović Andrea
Published: September 2011

Coating of zeolite nanoparticles, previously dispersed in Polycarboxylic acid (PCA) solution, on cellulose textile surface has several advanced technological applications. One of the possible usages is for the Durable Press finishing enabling simultaneous enhanced antimicrobial or flame retardant properties. In this study, one of the polycarboxylic acid crosslinking agents, Citric acid (CA) is used to coat cotton fabric in the presence of synthesized zeolite applied as a catalyst. Cotton fabric samples were padded with a suspension containing zeolite powder in aqueous solution of CA crosslinking agent. Drying and curing of coated samples was performed at different curing conditions, either in a microwave oven or in conventional dryer. Scanning electron microscope (SEM) is used to characterize the surface morphology and confirm bonding of zeolite particles to cellulose fibers. Further characterization of coated surface is performed by attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy while the effects of microwave irradiation on zeolite nanoparticles bonding is estimated by thermogravimetric analysis.
Magnetisation and Magneto-Resistance Study of Ferromagnetic Metal/Half Metallic Double Perovskite Bi-Layers
Authors: McCann Duncan M. , Williams Grant V. M. , Hyndman Adam R. , Stephen Jibu
Published: September 2011

We observe a large magneto-resistance in very thin Ba2FeMoO6films of ~-12% at 10K, which is not significantly changed when thin NiFe/Ba2FeMoO6bi-layers are made. This suggests that the magneto-resistance in both cases is dominated by inter-grain tunnelling in the Ba2FeMoO6thin film. There is an anomalous peak in the resistance at ~300K in the bi-layer film that can not be easily explained. However, we know that the temperature where this peak occurs is close to the Ba2FeMoO6Curie temperature.
Growth and Transport Properties of Sr-Doped Lanthanum Titanate Thin Films on LaAlO3
Authors: Sung Huang Huei , Tsai Jiun Tzuen , Lin Cheng Hsueh , Chen Shing Yu , Fan Jung Chuan , Lin Chun Rong
Published: September 2011

Sr-doped LaTiO3 (SLTO) thin epitaxial films on LaAlO3 (100) have been fabricated by the off-axis rf magnetron co-sputtering system. The dopant Sr2+ ions were expected substituting La3+ ions in the films to introduce the hole carriers. The X-ray diffraction shows that the [001] direction of the SLTO films is perpendicular to the substrate surface. The in-situ grown specimens were measured the temperature dependence of resistivity and the Hall coefficients to study the transport properties. The Hall measurements show that the carrier is electron for Sr-doping over 16%. The temperature dependence of the resistance shows that the n-type films are metallic and deviate from free electron gas model obviously. We found the behaviour could be well described by the small-polaron coherent motion model.
Characterization of the Structural and Electrical Properties of Ion Beam Sputtered ZnO Films
Authors: Murmu Peter P. , Kennedy John , Ruck Ben J. , Markwitz Andreas
Published: September 2011

We report the structural and electrical properties of ion beam sputtered ZnO films vacuum annealed at varying temperatures. XRD results revealed that the films grow along thec-axis. The crystallite sizes increase from ~8 to ~30 nm upon annealing at 800ºC. Annealing aided to recover the compressive strain and regain the standard lattice parameter values. The RMS surface roughness increased to ~5.0 nm after annealing at 800ºC as observed in AFM micrographs. Increased resistivity on the annealed films suggested that the oxygen vacancies are compensated by de-trapped oxygen at grain boundaries.
Effect of Thermal Annealing on Electrical Properties of Si-LiNbO3
Authors: Ievlev Valentin M. , Sumets Maxim P. , Kostyuchenko Alexander V.
Published: September 2011

The substructure and electrical properties of the films with the thickness up to 2.0 µm deposited on Si by the methods of the radio frequency magnetron and ion-beam sputtering of a LiNbO3 target have been investigated. It has been established that in thermally annealed samples an activated conduction mechanism with variable jump distance takes place. As a result of thermal annealing a decrease in the charge localization centers (CLC) in the LiNbO3 films from Nt=3·1018cm-3 to Nt=3·1016cm-3 occurs.
Phase Development and Dielectric Properties of 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3 Ceramic
Authors: Roongtao Rachanusorn , Rugmai Supagorn , Vittayakorn Wanwilai C.
Published: September 2011

The 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3ceramics has been synthesized through a conventional mixed-oxide by using BT nanopowder and BMN micropowder. The phase purity of the powders and the ceramics was examined using X-ray diffraction (XRD). The 0.98BT-0.02BMN powders were sintered to 92% of the theoretical density at a temperature of 1300 °C for 2 h. The microstructure of the sintered surface was investigated using scanning electron microscopy (SEM). The dielectric constant (εr) and loss factor (tanδ) of the sintered pellets at Curie temperture were 3000 and 0.015, respectively.
Thin-Film Deposition of Mixed-Conducting Ceramic Membranes
Authors: Smith Geoff D. , Wu Jeremy P. , Brown Ian William Murray
Published: September 2011

Thin films of oxygen-conducting materials are expected to exhibit enhanced oxygen permeability, due to their reduced diffusion path. Two such materials, yttria-stabilised zirconia (YSZ) and ceria gadolinium oxide (CGO), were deposited onto anodic alumina substrates by electron beam evaporation of the parent materials. Continuous films 200-400 nm thick were characterised through SEM and XRD analysis. It was found that the substrate temperature during deposition strongly influenced the structure and stability of the films, with the original simple cubic structure being retained at deposition temperatures above 450 °C. Attempts to deposit thin films of a yttria-doped SrCoO3-δ perovskite were unsuccessful, due to melting of the material during deposition and thermal diffusion into the substrate.
The complementary power of pH and lake-water organic carbon reconstructions for discerning the influences on surface waters across decadal to millennial time scales
Authors: Rosén P. , Bindler R. , Korsman T. , Mighall T. , Bishop K.
Published: September 2011

Abstract. Lysevatten, a lake in southwest Sweden, has experienced both acidification and recent changes in the amount of lake-water organic carbon (TOC), both causing concern across Europe and North America. A range of paleolimnological tools – diatom-inferred pH, inferred lake-water TOC from visible-near-infrared spectroscopy (VNIRS), multi-element geochemistry and pollen analysis, combined with geochemical modeling were used to reconstruct the lake's chemistry and surroundings back to the most recent deglaciation 12 500 years ago. The results reveal that the recent anthropogenic impacts are similar in magnitude to the long-term variation driven by natural catchment changes and early agricultural land use occurring over centuries and millennia. The combined reconstruction of both lake-water TOC and lithogenic element delivery can explain the major changes in lake-water pH and modeled acid neutralizing capacity during the past 12 500 years. The results raise important questions regarding what precisely comprises "reference" conditions (i.e., free from human impacts) as defined in the European Water Framework Directive.
Creating a catchment scale perspective for river restoration
Authors: Benda L. , Miller D. , Barquín J.
Published: September 2011

Abstract. One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2), in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we used computer tools to examine the spatial patterns of fluvial landscapes that are associated with five domains of hydro-geomorphic processes and landforms. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to hillslope and valley topography, river network structure, and channel elevation profiles. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.
New significance test methods for Fourier analysis of geophysical time series
Authors: Zhang Z. , Moore J.
Published: September 2011

Abstract. When one applies the discrete Fourier transform to analyze finite-length time series, discontinuities at the data boundaries will distort its Fourier power spectrum. In this paper, based on a rigid statistics framework, we present a new significance test method which can extract the intrinsic feature of a geophysical time series very well. We show the difference in significance level compared with traditional Fourier tests by analyzing the Arctic Oscillation (AO) and the Nino3.4 time series. In the AO, we find significant peaks at about 2.8, 4.3, and 5.7 yr periods and in Nino3.4 at about 12 yr period in tests against red noise. These peaks are not significant in traditional tests.
Use of a thermal imager for snow pit temperatures
Authors: Shea C. , Jamieson B. , Birkeland K. W.
Published: September 2011

Abstract. Weak snow of interest to avalanche forecasting often forms and changes as thin layers. Thermometers, the current field technology for measuring the temperature gradients across such layers – and for thus estimating the expected vapour flux and future type of crystal metamorphism – are difficult to use at distances shorter than 1 cm. In contrast, a thermal imager can provide thousands of simultaneous temperature measurements across small distances with better accuracy. However, a thermal imager only senses the exposed surface, complicating its methods for access and accuracy with respect to buried temperatures. This paper presents methods for exposing buried layers on pit walls and using a thermal imager to measure temperatures on these walls, correct for lens effects, adjust temperature gradients adjust time exposed, and calculate temperature gradients over millimetre distances. We find lens error on temperature gradients to be on the order of 0.03 °C between image centre and corners. We find temperature gradient change over time to usually decrease – as expected with atmospheric equalization as a strong effect. Case studies including thermal images and visual macro photographs of crystals, collected during the 2010–2011 winter, demonstrate large temperature differences over millimetre-scale distances that are consistent with observed kinetic metamorphism.
Good Teachers, Scholarly Teachers and Teachers Engaged in Scholarship of Teaching and Learning: A Case Study from McMaster University, Hamilton, Canada
Authors: Vajoczki Susan , Savage Philip , Martin Lynn , Borin Paola , Kustra Erika D.H.
Published: September 2011

This paper defines and operationalizes definitions of good teaching, scholarly teaching and the scholarship of teaching and learning in order to measure characteristics of these definitions amongst undergraduate instructors at McMaster University. A total of 2496 instructors, including all part-time instructors, were surveyed in 2007. A total of 339 surveys were returned. Indices of good teaching, scholarly teaching and scholarship of teaching and learning were developed. The data illustrated a strong correlation between good teaching and scholarly teaching and between scholarly teaching and scholarship of teaching and learning. The perceived value placed upon teaching varied across the different Faculties. New instructors and those engaged in scholarly teaching and scholarship of teaching and learning perceived teaching to be more valued than their peers.
Le présent article définit et opérationnalise les définitions d’enseignement efficace[1], d’enseignement érudit[2] et de la publication sur l'enseignement supérieur[3] afin de mesurer les caractéristiques de ces définitions chez les enseignants de premier cycle de l’Université McMaster. Au total, 2 496 enseignants, y compris tous ceux qui travaillent à temps partiel, ont été sondés en 2007 et 339 questionnaires ont été retournés. Les chercheurs ont élaboré des indices d’un bon enseignement, d’un très bon enseignement et d’un excellent enseignement. Les données illustrent une forte corrélation entre un bon enseignement et un très bon enseignement, de même qu’entre un très bon enseignement et un excellent enseignement. La valeur perçue accordée à l’enseignement variait selon les différentes facultés. Les nouveaux enseignants pratiquant un très bon enseignement et un excellent enseignement trouvaient l’enseignement plus utile que leurs pairs.
[1] good teaching, [2] scholarly teaching, [3] scholarship of teaching and learning
Airline Pricing Strategies Versus Consumer Rights
Authors: Bischoff Gregor , Maertens Sven , Grimme Wolfgang
Published: September 2011

As airlines price-discriminate, business travelers usually have to pay prices above average cost for flexible tickets. This allows the airlines to offer cheaper tickets to leisure travelers, albeit in the form of restrictive fares. Methods used by business travelers to circumvent strict rules of discounted fares are known as “cross-” and “hidden-city” ticketing. However, according to IATA Recommended Practice 1724, Article 3.3.1, airlines reserve the right to cancel all remaining legs of a booking if flight coupons are not used in full and sequential order. We discuss this issue from both a legal and commercial perspective. After providing an overview of various legal opinions, we predict the impact on airline marketing and economics if the described forms of fare rule circumvention are allowed.
An Analysis of the Relationship between Passenger Loyalty and Consumer Buying Behavior for Network and Low-Cost Carriers
Authors: Chacon Juliano , Mason Keith J.
Published: September 2011

This essay investigates passenger loyalty and consumer buying behavior within the airline industry using an Internet-based survey approach. Four hundred and seven air travelers from network and low-cost carriers are segmented into Dick and Basu’s (1994) loyalty groups (“Loyal,” “Latent Loyalty,” “Spurious Loyalty,” and “No Loyalty”), derived from their relative attitude and repeat patronage toward the airline that they used the most. To investigate the significance of the relationships between the loyalty groups and passengers’ individual characteristics, an evaluation of purchasing criteria within loyalty groups was conducted. Frequent-flier program (FFPs) and range of destinations were found to be the product variables rated highest among the most frequent travelers from network carriers. Passengers of low-cost carriers rated price, schedule, and airport location most highly. The results show that network carriers can develop a sizable group of loyal passengers. These airlines also have a substantial group of passengers who display latent loyalty that may be converted into fully loyal passengers by better meeting their needs. In comparison, very few travelers displayed any level of loyalty to their most-used low-cost carrier.
Preparation and properties of halogen‐free flame‐retarded phthalonitrile–epoxy blends
Authors: Zhao Xin , Lei Yajie , Zhao Rui , Zhong Jiachun , Liu Xiaobo
Published: September 2011

Halogen‐free flame‐retarded blends composed of 2,2‐bis[4‐(3,4‐dicyanophenoxy) phenyl] propane (BAPh) and epoxy resin E‐44 (EP) were successfully prepared with 4,4′‐diaminodiphenyl sulfone as a curing additive. The structure of the copolymers was characterized by Fourier transform infrared spectroscopy, which showed that epoxy groups, a phthalocyanine ring, and a triazine ring existed. The limiting oxygen index values were over 30, and the UL‐94 rating reached V‐0 for the 20 : 80 (w/w) BAPh/EP copolymers. Differential scanning calorimetry and dynamic rheological analysis were employed to study the curing reaction behaviors of the phthalonitrile/epoxy blends. Also, the gelation time was shortened to 3 min when the prepolymerization temperature was 190°C. Thermogravimetric analysis showed that the thermal decomposition of the phthalonitrile/epoxy copolymers significantly improved with increasing BAPh content. The flexible strength of the 20:80 copolymers reached 149.5 MPa, which enhanced by 40 MPa compared to pure EP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Kinetics of the hydrogenation of NBR by hydrazine and oxygen, using selenium as a catalyst
Authors: Schulz Gracélie A. S. , Comin Edson , de Souza Roberto F.
Published: September 2011

The kinetics of hydrogenation of the acrylonitrile‐polybutadiene (NBR) rubber by the action of hydrazine in the presence of selenium and oxygen was studied by varying reaction parameters such as latex and catalyst concentrations. The method of initial rates gives a reaction order of 0.91 and a rate constant of 3.2 × 101 L mol−1 h−1 in relation to the NBR latex concentration, and an order of 0.86 and a rate constant of 3.3 × 101 L mol−1 h−1 in relation to the catalyst concentration. Based on these values, a first‐order mechanism with the formation of a diimide intermediate is suggested, which is formed through the oxidation of hydrazine in an oxygen atmosphere in the presence of selenium catalyst. This diimine species reacts rapidly, reducing the carbon–carbon double bonds of NBR resulting in the formation of HNBR rubber. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Mechanisms and kinetics of thermal degradation of poly(butylene succinate‐co‐propylene succinate)s
Authors: Lu Shih‐Fu , Chen Ming , Chen Chi He
Published: September 2011

Poly(butylene succinate) (PBSu) and two PBSu‐rich poly(butylene succinate‐co‐propylene succinate)s were studied. Copolyesters were characterized as random copolymers, based on 13C‐NMR spectra. TGA‐FTIR was used to monitor the degradation products at a heating rate of 5°C/min under N2. FTIR spectra revealed that the major products were anhydrides, which were formed following two cyclic intramolecular degradation mechanisms by the breaking of the weak O‐CH2 bonds around succinate groups. Thermal stability at heating rates of 1, 3, 5, and 10°C/min under N2 was investigated using TGA. The model‐free methods of the Friedman and Ozawa equations are useful for studying the activation energy of degradation in each period of mass loss. The results reveal that the random incorporation of minor propylene succinate units into PBSu did not markedly affect their thermal resistance. Two model‐fitting mechanisms were used to determine the mass loss function f(α), the activation energy and the associated mechanism. The mechanism of autocatalysis nth‐order, with f(α) = αm(1 − α)n, fitted the experimental data much more closely than did the nth‐order mechanism given by f(α) = (1 − α)n. The obtained activation energy was used to estimate the failure temperature (Tf). The values of Tf for a mass loss of 5% and an endurance time of 60,000 h are 160.7, 155.5, and 159.3°C for PBSu and two the copolyesters, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Thermal and mechanical properties of LDPE/sisal fiber composites compatibilized with functionalized paraffin waxes
Authors: Nhlapo L. P. , Luyt A. S.
Published: September 2011

The effect of maleic anhydride‐grafted hard paraffin wax (MA‐g‐wax) and oxidized hard paraffin wax (OxWax), as possible compatibilizers, on the morphology, thermal and mechanical properties of LDPE/sisal fiber composites were examined. The differential scanning calorimetry (DSC) results show that sisal alone did not change the crystallization behavior of LDPE, while the two waxes influenced the crystallization behavior of LDPE in different ways, whether mixed with LDPE alone or in the presence of sisal. The thermal properties seem to be influenced by the fact that the waxes preferably crystallize around the short sisal fibers, and by the fact that the two waxes have different compatibilities with LDPE. The TGA results show an increase in the thermal stability of the blends in the presence of the two waxes, with LDPE/OxWax showing a more significant improvement. The presence of wax, however, reduced the thermal stability of the LDPE/sisal/wax composites. The presence of OxWax and MA‐g‐wax similarly influenced the tensile properties of the composites. Both waxes similarly improved the modulus of the compatibilized composites, but in both cases the tensile strengths were worse, probably because of a fairly weak interaction between LDPE and the respective waxes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Recombinant immunosuppressive protein from Pimpla hypochondrica venom (rVPr1) increases the susceptibility of Mamestra brassicae larvae to the fungal biological control agent, Beauveria bassiana
Authors: Richards Elaine H. , Bradish Hannah , Dani M. Paulina , Pietravalle Stéphane , Lawson Ailsa
Published: September 2011

Although fungi are used to control a variety of insect pests, it is accepted that their usage could be increased if their efficacy was greater. The outcome of the interaction of a fungus and a pest insect may be influenced by a number of criteria, including the ability of the insect to mount effective immune responses against the pathogen. In view of this, we aimed to determine if a recombinant immunosuppressive wasp venom protein (rVPr1) can increase the susceptibility of larvae of the lepidopteran pest, Mamestra brassicae, to the fungal biological control agent, Beauveria bassiana. Bioassays indicated that when larvae were injected with 3.5 µl of rVPr1 and 100 B. bassiana conidia (combined injection assays), a significant reduction in survival of larvae occurred compared with each treatment on its own (P = 0.006). Similar results were obtained when larvae were dipped in a solution containing 3 × 106 B. bassiana conidia per ml and then injected with 3.5 µl of rVPr1 2 days later (topical application assays), (P<0.001). These results indicate that rVPr1 can increase the efficacy of B. bassiana toward a lepidopteran pest, and are discussed within the context of insect immune responses and integrated pest management. © 2011 Wiley Periodicals, Inc.
Bioinsecticidal activity of Murraya koenigii miraculin‐like protein against Helicoverpa armigera and Spodoptera litura
Authors: Gahloth Deepankar , Shukla Umesh , Birah Ajanta , Gupta Gorakh P. , Ananda Kumar P. , Dhaliwal Harcharan S. , Sharma Ashwani K.
Published: September 2011

Miraculin‐like proteins, belonging to the Kunitz superfamily, are natural plant defense agents against pests and predators, and therefore are potential biopesticides for incorporation into pest‐resistant crops. Here, a miraculin‐like protein from Murraya koenigii was assessed for its in vitro and in vivo effects against two polyphagous lepidopteran insect pests, Helicoverpa armigera and Spodoptera litura. M. koenigii miraculin‐like protein (MKMLP) inhibited the trypsin‐like activity and total protease activity of H. armigera gut proteinases (HGP) by 78.5 and 40%, respectively, and S.litura gut proteinases (SGP) by 81 and 48%, respectively. The inhibitor was stable and actively inhibited the proteolysis of both HGP and SGP enzymes for up to 72 h. Incorporation of MKMLP into artificial diet adversely affected the growth and development of pests in a dose‐dependent manner. After 10 days of feeding on diets containing 200 µM MKMLP, larval weight was reduced to 69 and 44.8% and larval mortality was increased to 40 and 43.3% for H. armigera and S litura, respectively. The LC50 of MKMLP was 0.34 and 0.22% of the diet for H.armigera and S. litura, respectively. These results demonstrate the efficacy of MKMLP as a potential plant defense agent against H. armigera and S. litura. © 2011 Wiley Periodicals, Inc.
Hyperthermia induces upregulation of Connexin43 in the golden hamster neural tube
Authors: Zhang Jing , Chen Feng‐zhe , Gao Qing , Sun Jin‐hao , Tian Guang‐ping , Gao Ying‐mao
Published: September 2011

BACKGROUND

During early embryonic development, maternal exposure to hyperthermia induces neural tube defects (NTDs). Connexins are essential for the formation of gap junctions and Connexin43 (Cx43) is crucially involved in neural tube development. This study was designed to explore the potential role of Cx43 in NTDs induced by hyperthermia.

METHODS

Using PCR, the Cx43 cDNA was screened from the cDNA library of the neural tube from golden hamsters treated with hyperthermia. By Northern blot, the expression of Cx43 in heat‐treated and control groups of the golden hamsters at day 8.5 after mating was detected. Finally, by in situ hybridization and RT‐PCR, the expression of Cx43 was examined in the neural tube at different time points after heat treatment.

RESULTS

Cx43 was stably expressed in heat‐treated and control groups of the golden hamsters, whereas the expression was evidently higher in the heat‐treated group. Cx43 expression in the neural tube at different time points after heat treatment was significantly higher than in control groups (p < 0.01). Hyperthermia did not induce any mutations in Cx43 cDNA.

CONCLUSIONS

Our data provide the first evidence that hyperthermia induces upregulation of Cx43 in the golden hamster neural tube. NTDs caused by hyperthermia may be intimately related with the overexpression of Cx43. Birth Defects Research (Part A) 2012. © 2011 Wiley Periodicals, Inc.
ChemInform Abstract: Electronic Conduction in Polymers, Carbon Nanotubes and Graphene
Authors: Kaiser Alan B. , Skakalova Viera
Published: September 2011

Review: 122 refs.
Ndel1, Nudel ( Noodle): Flexible in the cell?
Authors: Chansard Mathieu , Hong Ji‐Ho , Park Young‐Un , Park Sang Ki , Nguyen Minh Dang
Published: September 2011

Nuclear distribution element‐like 1 (Ndel1 or Nudel) was firstly described as a regulator of the cytoskeleton in microtubule and intermediate filament dynamics and microtubule‐based transport. Emerging evidence indicates that Ndel1 also serves as a docking platform for signaling proteins and modulates enzymatic activities (kinase, ATPase, oligopeptidase, GTPase). Through these structural and signaling functions, Ndel1 plays a role in diverse cellular processes (e.g., mitosis, neurogenesis, neurite outgrowth, and neuronal migration). Furthermore, Ndel1 is linked to the etiology of various mental illnesses and neurodegenerative disorders. In the present review, we summarize the physiological and pathological functions associated with Ndel1. We further advance the concept that Ndel1 interfaces GTPases‐mediated processes (endocytosis, vesicles morphogenesis/signaling) and cytoskeletal dynamics to impact cell signaling and behaviors. This putative mechanism may affect cellular functionalities and may contribute to shed light into the causes of devastating human diseases. © 2011 Wiley Periodicals, Inc.
New insights into cathelicidin modulation of adaptive immunity
Authors: Wuerth Kelli , Hancock Robert E. W.
Published: September 2011

Cathelicidins are a family of host defence peptides that are known to selectively alter innate immunity in response to infection and other changes in immune status. A study in this issue of the European Journal of Immunology elucidates a new role for mouse cathelin‐related antimicrobial peptide in the adaptive immune response by clearly demonstrating for the first time that a cathelicidin can alter T‐cell‐dependent activation of the humoral response in vivo and thus modulate the activities of both B and T lymphocytes.
Quantifying gravel overlap and dislodgement forces on natural river bars: implications for particle entrainment
Authors: Sanguinito Sean , Johnson Joel
Published: September 2011

Equations for predicting particle entrainment typically assume that clast weight is the only factor resisting motion in the force balance on individual grains. In this work, increases in the force required to dislodge surface particles due to overlapping by surrounding clasts is quantified. Field data were collected at two subaerially‐exposed bars along the Colorado River in central Texas, USA, with median gravel diameters (D50) of 37 and 64 mm. Clast size, shape, weight, the force required for vertical removal, and the fraction of clast area covered by surrounding grains were measured. Small hooks were glued to individual clasts without disrupting their positions and quasi‐static peak forces required to vertically dislodge each clast were measured using a force gauge. Clasts were also colored with dye before being dislodged, and image analysis was used to calculate the fraction of clast surface area covered by surrounding grains. The effect of overlap on the particle force balance is quantified by defining the ‘excess force ratio’ as the dislodgement force divided by the weight of the clast. Excess force ratio varies weakly but systematically with clast size: lifting larger clasts can require forces up to two times the clast's weight, while smaller clasts can require forces up to seven times their weight. The fraction of clast surface area covered by surrounding particles is also weakly correlated with excess force ratio. By assuming that critical shear stresses are proportional to the excess force ratio, the effect that overlap alone may have on particle entrainment is calculated. For a given size class, the most mobile grains should have critical shear stresses controlled only by their weight. However, clast overlap also causes broad distributions of critical stresses for partially‐exposed surface grains. The data quantify the significant fraction of bed area that should be less mobile than grain size alone would predict. Copyright © 2011 John Wiley & Sons, Ltd.