1,325 research outputs found
Measuring the effects of service value on behavioral intentions with a structural equation model
Son günlerde benzer hizmetleri, benzer fiyatlara sunabilen hizmet sektörü firmaları için ayırt edici özellik, sundukları yüksek hizmet değeridir. Hizmet firmalarının rakipleri arasında öne çıkmaları ancak müşterilerine sunacakları yüksek değerde hizmet ile mümkün olabilmektedir. Bu çalışma sağlık sektöründe hizmet veren hastanelerde hizmet değerinin müşterilerin gelecekteki davranışları üzerindeki etkisinin ölçülmesine yönelik Cronin ve diğerleri (2000) tarafından ortaya konan modelin bir parçasını içermektedir. Model, kayıp, hizmet değeri ve davranışsal niyet değişkenlerinden oluşan yapısal eşitlik modelidir. Araştırma modeli sağlık sektörüne uygulanarak, model değişkenleri arasındaki ilişkiler SPSS 13.0 ve LISREL 8.8 paket programları ile çözülmüş, ilgili sonuçlar elde edilmiştir.In last few years, high service value has become a distinguishable characteristic for firms which provide similar services with similar prices. If the firms provide the services with high service value, then they can be the leader among their rivals. In this paper, a part of Cronin et. al’s (2000) model is used and the effects of service value on behavioral intentions have been analyzed. The model is a structural equation model with three variables which are sacrifice, service value, and behavioral intention. For analyses SPSS 13.0 and LISREL 8.8 programs were used
Extremely fast and highly selective detection of nitroaromatic explosive vapours using fluorescent polymer thin films
Cataloged from PDF version of article.A novel sensing material based on pyrene doped polyethersulfone worm-like structured thin film is developed using a facile technique for detection of nitroaromatic explosive vapours. The formation of pi-pi stacking in the thin fluorescent film allows a highly sensitive fluorescence quenching which is detectable by the naked eye in a response time of a few seconds
Soft biomimetic tapered babostructures for large-area antireflective surfaces and SERS sensing
Cataloged from PDF version of article.We report a facile fabrication method for the fabrication of functional large area nanostructured polymer films using a drop casting technique. Reusable and tapered silicon molds were utilized in the production of functional polymers providing rapid fabrication of the paraboloid nanostructures at the desired structural heights without the requirement of any complex production conditions, such as high temperature or pressure. The fabricated polymer films demonstrate promising qualities in terms of antireflective, hydrophobic and surface enhanced Raman spectroscopy (SERS) features. We achieved up to 92% transmission from the single-side nanostructured polymer films by implementing optimized nanostructure parameters which were determined using a finite difference time domain (FDTD) method prior to production. Large-area nanostructured films were observed to enhance the Raman signal with an enhancement factor of 4.9 x 10(6) compared to bare film, making them potentially suitable as freestanding SERS substrates. The utilized fabrication method with its demonstrated performances and reliable material properties, paves the way for further possibilities in biological, optical, and electronic applications
Finite-size scaling for non-linear rheology of fluids confined in a small space
We perform molecular dynamics simulations in order to examine the rheological
transition of fluids confined in a small space. By performing finite-size
scaling analysis, we demonstrate that this rheological transition results from
the competition between the system size and the length scale of cooperative
particle motion.Comment: 4pages, 8 figure
Surface Roughness and Effective Stick-Slip Motion
The effect of random surface roughness on hydrodynamics of viscous
incompressible liquid is discussed. Roughness-driven contributions to
hydrodynamic flows, energy dissipation, and friction force are calculated in a
wide range of parameters. When the hydrodynamic decay length (the viscous wave
penetration depth) is larger than the size of random surface inhomogeneities,
it is possible to replace a random rough surface by effective stick-slip
boundary conditions on a flat surface with two constants: the stick-slip length
and the renormalization of viscosity near the boundary. The stick-slip length
and the renormalization coefficient are expressed explicitly via the
correlation function of random surface inhomogeneities. The effective
stick-slip length is always negative signifying the effective slow-down of the
hydrodynamic flows by the rough surface (stick rather than slip motion). A
simple hydrodynamic model is presented as an illustration of these general
hydrodynamic results. The effective boundary parameters are analyzed
numerically for Gaussian, power-law and exponentially decaying correlators with
various indices. The maximum on the frequency dependence of the dissipation
allows one to extract the correlation radius (characteristic size) of the
surface inhomogeneities directly from, for example, experiments with torsional
quartz oscillators.Comment: RevTeX4, 14 pages, 3 figure
Oscillating epidemics in a dynamic network model: stochastic and mean-field analysis
An adaptive network model using SIS epidemic propagation with link-type-dependent link activation and deletion is considered. Bifurcation analysis of the pairwise ODE approximation and the network-based stochastic simulation is carried out, showing that three typical behaviours may occur; namely, oscillations can be observed besides disease-free or endemic steady states. The oscillatory behaviour in the stochastic simulations is studied using Fourier analysis, as well as through analysing the exact master equations of the stochastic model. By going beyond simply comparing simulation results to mean-field models, our approach yields deeper insights into the observed phenomena and help better understand and map out the limitations of mean-field models
Yield conditions for deformation of amorphous polymer glasses
Shear yielding of glassy polymers is usually described in terms of the
pressure-dependent Tresca or von Mises yield criteria. We test these criteria
against molecular dynamics simulations of deformation in amorphous polymer
glasses under triaxial loading conditions that are difficult to realize in
experiments. Difficulties and ambiguities in extending several standard
definitions of the yield point to triaxial loads are described. Two
definitions, the maximum and offset octahedral stresses, are then used to
evaluate the yield stress for a wide range of model parameters. In all cases,
the onset of shear is consistent with the pressure-modified von Mises
criterion, and the pressure coefficient is nearly independent of many
parameters. Under triaxial tensile loading, the mode of failure changes to
cavitation.Comment: 9 pages, 8 figures, revte
Time-Resolved Studies of Stick-Slip Friction in Sheared Granular Layers
Sensitive and fast force measurements are performed on sheared granular
layers undergoing stick-slip motion, along with simultaneous imaging. A full
study has been done for spherical particles with a +-20% size distribution.
Stick-slip motion due to repetitive fluidization of the layer occurs for low
driving velocities. Between major slip events, slight creep occurs that is
variable from one event to the next. The effects of changing the stiffness k
and velocity V of the driving system are studied in detail. The stick-slip
motion is almost periodic for spherical particles over a wide range of
parameters, but becomes irregular when k is large and V is relatively small. At
larger V, the motion becomes smoother and is affected by the inertia of the
upper plate bounding the layer. Measurements of the period T and amplitude A of
the relative motion are presented as a function of V. At a critical value Vc, a
transition to continuous sliding motion occurs that is discontinuous for k not
too large. The time dependence of the instantaneous velocity of the upper plate
and the frictional force produced by the granular layer are determined within
individual slipping events. The force is a multi-valued function of the
instantaneous velocity, with pronounced hysteresis and a sudden drop prior to
resticking. Measurements of vertical displacement reveal a small dilation of
the material (about one tenth of the mean particle size in a layer 20 particles
deep) associated with each slip event. Finally, optical imaging reveals that
localized microscopic rearrangements precede (and follow) each slip event. The
behavior of smooth particles is contrasted with that of rough particles.Comment: 20, pages, 17 figures, to appear in Phys. Rev.
Simulations of the Static Friction Due to Adsorbed Molecules
The static friction between crystalline surfaces separated by a molecularly
thin layer of adsorbed molecules is calculated using molecular dynamics
simulations. These molecules naturally lead to a finite static friction that is
consistent with macroscopic friction laws. Crystalline alignment, sliding
direction, and the number of adsorbed molecules are not controlled in most
experiments and are shown to have little effect on the friction. Temperature,
molecular geometry and interaction potentials can have larger effects on
friction. The observed trends in friction can be understood in terms of a
simple hard sphere model.Comment: 13 pages, 13 figure
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