An E-Business Model Facilitating Service Provider Selection in B2C E-Commerce

The advent and expansion of the Internet and its applications, among them e-commerce, has provided new opportunities for the emergence of novel e-business models. A portion of these models are in the form of performing a mediatory role to provide some services for customers or businesses, and to facilitate transactions between them. In B2C e-commerce, often, a service consumer may supply his service demand from a range of providers and when he doesn\u27t have any transaction with many of them making an accurate decision becomes challenging. Therefore, he would need to interact with others to acquire relevant information. Current approaches for addressing this issue are generally rating-based and perform poorly. Recently, an experience-based approach has been proposed by ensoy et al [1]. This paper reviews this approach, analyzes its weaknesses and problems and proposes a new model to eliminate those problems, in which a third party assists the consumers in choosing their desired service providers

Flow-Induced Stresses and Displacements in Jointed Concrete Pipes Installed by Pipe Jacking Method

Transient flows result in unbalanced forces and high pressure in pipelines. Under these conditions, the combined effects of flow-induced forces along with sudden pipe displacements can create cracks in the pipeline, especially at the junctions. This situation consequently results in water leakage and reduced operational efficiency of the pipeline. In this study, displacements and stresses in a buried pressurized water transmission pipe installed by pipe jacking method are investigated using numerical modeling and considering interactions between fluid, pipe, and soil. The analyses were performed consecutively under no-flow, steady flow, and transient flow conditions, in order to investigate the effects of flow conditions on displacements and stresses in the system. Analyses of the results show that displacements and stresses in the jointed concrete pipes are significant under transient flow conditions. Moreover, because of pressure transient effects, maximum tensile stresses exceed the tensile strength of concrete at the junctions, leading to cracks and consequent water leakage

Generalized second law of thermodynamics in massive gravity

Here, we study the generalized second law (GSL) of thermodynamics in the framework of massive gravity. To do this, we consider a FRW universe filled only with matter and enclosed by the apparent horizon. In addition, we consider two models including generalized massive gravity (GMG) as well as dRGT massive gravity on de Sitter. For both models, we first study the dynamics of background cosmology and then explore the validity of GSL. We conclude that for the selected values of model parameters the GSL is respected.Comment: 22 pages, 5 figure

A non-parametric hysteresis model for magnetorheological

In this paper a new non-parametric hysteresis model is offered for simulation of behaviors of magneto-rheological dampers. The offered model takes the excitation frequency, amplitude and current as variables and because of that it is capable of estimating the hysteresis force in different stimulation conditions with a good level of accuracy. Also, the model has the required level of flexibility for simulation of different dampers. The model completion is free of all complications observed in other models. Finally, the accuracy of simulations provided by this model are compared with experimental data as well as two parametric and non-parametric models

Anesthesia in a pediatric patient with Xeroderma pigmentousoma: A case report

Xeroderma pigmentosum (XP) is an autosomal recessive genetic disorder with the following conditions: neurologic disorders that gradually progress and skin hypersensitivity to ultraviolet (UV). Inhalational anesthetic drugs should be avoided in these patients since they may induce DNA damage, also use of muscle relaxants should be kept to a minimum. Thus for XP patients, total intravenous anesthesia (TIVA) is more appropriate for inducing general anesthesia and airway manipulation must be kept to a minimum. We report a 6 year old boy with XP and its airway management and anesthesia during surger

Investigation of mass transfer, thermodynamics, and greenhouse gases properties in pennyroyal drying

In this research, kinetic analysis, energy, exergy, and greenhouse gases of a hybrid laboratory dryer (solar-hot air) are presented for pennyroyal. Drying was performed at input temperatures of 50, 60, and 70°C and air velocities of 0.6, 1.2, and 1.8 m/s. The effect of drying variables on moisture ratio, effective moisture diffusivity, specific energy consumption, energy utilization ratio, energy utilization, exergy efficiency, and exergy loss was investigated. The highest amounts of effective moisture diffusivity and specific energy consumption were 2.30 × 10−10 m2/s and 48.60 kWh/kg, respectively. Energy utilization and energy utilization ratio varied from 0.0064 to 0.0826 kJ/s and from 0.056 to 0.957, respectively. Exergy loss and exergy efficiency varied between 0.0037 to 0.0510 kJ/s and 0.2428 to 0.8731, respectively. In addition, by increasing the temperature and intake air velocity, drying rate increased and the emissions of greenhouse gases (CO2, SO2, and NOX) were reduced. Practical Applications: Modeling of the drying process is an important aspect of drying technology, especially in drying for industrial purposes. The aim of modeling is to select the most suitable drying method and the best operating conditions for obtaining the product. Some of the key issues in drying have been to reduce the price of the energy resources used, increase the drying efficiency, and improve the quality of the dried products. The concept of exergy is defined by the concept of reversible work. The concept of reversibility depends on energy balance and mass regardless of energy quality (exergy loss).</p

The Effect of Flow and Magnetic Twist on Resonant Absorption of Slow MHD Waves in Magnetic Flux Tubes

Observations show that there are twisted magnetic flux tubes and plasma flow throughout the solar atmosphere. The main purpose of this work is to obtain the damping rate of sausage modes in the presence of magnetic twist and plasma flow. We obtain the dispersion relation for sausage modes in slow continuity in an inhomogeneous layer under the conditions of magnetic pores, then we solve it numerically. For the selected density profile, the magnetic field, and the plasma flow as a function of radius across the inhomogeneous layer, we show that the effect of the twisted magnetic field on the resonance absorption at low speed of the plasma flow is greater than one at high speed