Application of the extended Kantorovich method to the bending of variable thickness plates

The governing equations of the classical plate theory for a uniform or a unidirectional variable thickness rectangular plate under transverse applied loading are solved by means of the extended Kantorovich method. The plate may be either simply supported or clamped along the edges. The solution procedure is iterative and must be carried out numerically. This necessitates the calculation of the two missing pieces of boundary data along the edges of the plate. The missing boundary data are determined utilizing the method of adjoints of the shooting method. The numerical values of the deflection and bending moments for uniform and variable thickness plates are compared with those from the exact solutions and finite element analysis, respectively.     

A CFD Analysis of Ventilation Effectiveness in a Partitioned Room

A numerical model has been developed to investigate the contaminant removal and air freshness in a ventilated two-zone enclosure. The average contaminants and the distributions of air age in each zone under variable positions of door, supply and exhaust are compared. The correlation between the average contaminants and each of the main parameters, such as door location, supply and exhaust positions etc., are presented, and the average air ages in both zones are illustrated against door position. It is found that the average air age in the upstream zone is less affected by the door position than that in the downstream zone, and that the door position near the side-walls seems to give better air circulation. It is also concluded that the supply and door positions affect the concentration in the upstream zone significantly, while the exhaust location does not seem to influence the average concentration in either the upstream or the downstream zone.     

Optically anisotropic fragments in a Western Canadian subbituminous coal

Large Isotropic and anisotropic, angular and rounded fragments of inertinite were found in a Canadian subbituminous coal (%R oil = 0.50). The istropic fragments included pyrofusinite, macrinite and pseudovitrinite with pre-oxidized, heat-treated fragments showing oxidation rims. The anisotropic fragments include the heat-treated residue of liptinite, e.g. resinite showing granular anisotropy, pyrolytic carbon and fragments of vitrinite showing basic anisotropy. The morphology of inertinite fragments is described and an attempt is made to correlate these particles with heat-affected coal macerals. The occurrence of pyrolytic carbon with a reflectance of 3.11% and of liptinite showing anisotropy in a coal matrix with a reflectance of 0.50% is unusual. It indicates the detrital nature of the pyrolytic carbon. The formation of isotropic and anisotropic inertinite was possibly due to a thermal event, perhaps a wood or swamp fire. The pseudovitrinite found in these coals may have been formed by heat-treatment of fossil oxidized vitrinite fragments. The anisotropic fragments in the coals (e.g. pyrolytic carbon and anisotropic vitrinite), are detrital and are grouped with inertodetrinite.     

Use of the dendograph for data processing in fuel science

In fuel science there is a need to present the relationships between the elements of a group of variables or a group of samples as tables of data. The dendrograph, a derivative of the dendogram, is a method used for general cluster analysis. It offers an improvement by providing an irregular spacing of the objects classified on the x axis. The mathematical basis of this method is described as unweighted pair group method of clustering.     

Thermal Properties of the Binary‐Filler Hybrid Composites with Graphene and Copper Nanoparticles

The thermal properties of epoxy‐based binary composites comprised of graphene and copper nanoparticles are reported. It is found that the “synergistic” filler effect, revealed as a strong enhancement of the thermal conductivity of composites with the size‐dissimilar fillers, has a well‐defined filler loading threshold. The thermal conductivity of composites with a moderate graphene concentration of f_g = 15 wt% exhibits an abrupt increase as the loading of copper nanoparticles approaches f_Cu ≈ 40 wt%, followed by saturation. The effect is attributed to intercalation of spherical copper nanoparticles between the large graphene flakes, resulting in formation of the highly thermally conductive percolation network. In contrast, in composites with a high graphene concentration, f_g = 40 wt%, the thermal conductivity increases linearly with addition of copper nanoparticles. A thermal conductivity of 13.5 ± 1.6 Wm^?1K^?1 is achieved in composites with binary fillers of f_g = 40 wt% and f_Cu = 35 wt%. It has also been demonstrated that the thermal percolation can occur prior to electrical percolation even in composites with electrically conductive fillers. The obtained results shed light on the interaction between graphene fillers and copper nanoparticles in the composites and demonstrate potential of such hybrid epoxy composites for practical applications in thermal interface materials and adhesives.     

Conceptual feature generation for textual information using a conceptual network constructed from Wikipedia

A proper semantic representation of textual information underlies many natural language processing tasks. In this paper, a novel semantic annotator is presented to generate conceptual features for text documents. A comprehensive conceptual network is automatically constructed with the aid of Wikipedia that has been represented as a Markov chain. Furthermore, semantic annotator gets a fragment of natural language text and initiates a random walk to generate conceptual features that represent topical semantic of the input text. The generated conceptual features are applicable to many natural language processing tasks where the input is textual information and the output is a decision based on its context. Consequently, the effectiveness of the generated features is evaluated in the task of document clustering and classification. Empirical results demonstrate that representing text using conceptual features and considering the relations between concepts can significantly improve not only the bag of words representation but also other state‐of‐the‐art approaches.     

Active fuzzy modeling for estimating problems in hydrocarbon reservoirs

While active learning method (ALM) uses error as the learning parameter, selection of the validation data is still challenging. In this paper, to prevent form encountering with sample size problem, we applied an error-independent version of ALM that we call the active fuzzy modeling (AFM) with a distance threshold to model parameters of hydrocarbon reservoirs. In this paper, we demonstrate that measuring the generalization error is a vital factor in the process of ALM. Regression (R) and mean squared error (MSE) for estimating RHOB by AFM were 0.96 and 0.0032, respectively. On the other hand, R of 0.91, 0.89 and 0.92 and MSE of 0.0051, 0.0067 and 0.0047 for ANN, TS-FIS and NF, respectively, illustrate that AFM performs much better in comparison with conventional modeling approaches and produces more reliable results. Comparing the results of the presented method with ANN, TS-FIS and NF in aspect of rapidity, robustness, storage, complexity and acceptability in estimating RHOB reports the accuracy and high-performance behavior of AFM. This method is illustrated by an example of an oil field at NW Persian Gulf.     

Design of an all optical half-adder based on 2D photonic crystals

The present study was designed and simulated for an all optical half-adder, based on 2D photonic crystals. The proposed structure in this work contains a hexagonal lattice. The main advantages of the proposed designation can be highlighted as its small sizing as well as simplicity. Furthermore, the other improvement of this half-adder can be regarded as providing proper distinct space in output between “0” and “1” as logical states. This improvement reduces the error in the identification of logical states (i.e., 0 and 1) at output. Because of the high photonic band gap for transverse electric (TE) polarization, the TE mode calculations are done to analyze the defected lines of light. The logical values of “0” and “1” were defined according to the amount of electrical field.     

Low temperature dynamic mechanical response of porous Vycor glass as a function of moisture content

An experimental apparatus designed to measure automatically the internal friction and the elastic modulus of solid beams based on the resonance principle is described. The internal friction and the elastic modulus of porous Vycor glass beams containing different amounts of water has been measured as a function of temperature from 25 to –160° C. Two transitions are evident in the response: the capillary transition (–40 to 0° C) caused by freezing of capillary condensed water, and the adsorbate transition (centred around –85° C) associated with a gradual solidification of water adsorbed near the pore surfaces. More than half of all the water in a saturated beam freezes during the capillary transition, but this ice contributes only modestly to the elastic modulus of the beam which implies that there is little contact between the ice and the glass matrix. Further cooling into the adsorbate transition temperature range is believed to cause a gradual solidification of the adsorbed water, until at very low temperatures the adsorbed layer is glassy and effectively cements the glass matrix and the ice together resulting in a large increase in the elastic modulus of the beam.     

Experimental and CFD analysis of photocatalytic gas phase vinyl chloride (VC) oxidation

Photocatalytic destruction of gas phase vinyl chloride (VC) was examined using experimental and computational fluid dynamics (CFD) approaches. Experimental work involved using a differential photoreactor for determining kinetics of oxidation and an annular flow photoreactor for overall removal investigations as well as comparison with CFD models. The kinetic data obtained from differential photoreactor were used to model and predict the performance of the annular photoreactor using CFD. The photocatalytic oxidation of VC followed first order kinetics for inlet concentrations up to about and CFD was able to predict the removal of VC in the system. Both experimental and CFD modeling showed the removal of VC in the system increased with increasing the VC loading rate. CFD analysis of the photoreactor also provided insight into the detailed concentration gradient of VC within the reactor. The modeling results indicated significant radial VC concentration gradient and non-uniform flow distributions in the annular photoreactor. This non-uniform flow distribution, in turn, resulted in short circuiting of the VC contaminated gas and may have resulted in less than optimum removal efficiency for VC in the annular reactor over the entire range of inlet VC concentrations. Overall, the information provided by CFD modeling and simulation showed to be valuable for reactor design modification and for improving the reactor performance.