This paper explores the flow of dusty fluid over a stretching rotating disk with thermal radiation. Further, the convective boundary condition is considered in this modeling. The described governing equations are reduced to ordinary differential equations by using apt similarity transformations and then they are numerically solved using Runge–Kutta–Fehlberg-45 scheme. To gain a clear understanding of the current boundary layer flow problem, the graphical results of the velocity and thermal profiles, shear stresses at the disk, and Nusselt number are drawn. Results reveal that the increase in the value of the porosity parameter reduces the velocity of both particle and fluid phases. The increase in the value of the Biot number improves the temperature gradient of both particle and fluid phases. The rise in the value of the radiation parameter advances the heat transference of both phases. The rise in the value of the Biot number improves the rate of heat transfer. Finally, increasing the value of the radiation parameter improves the rate of heat transfer. 相似文献
A C0 finite element formulation of the higher-order theory is used to determine the natural frequencies of isotropic, orthotropic and layered anisotropic composite and sandwich plates. The material properties that are typical of high modulus fibre reinforced composites are used to show the parametric effects of plate aspect ratio, length-to-thickness ratio, degree of orthotropy, number of layers and lamination angle/scheme. The present theory is based on a higher-order displacement model and the three-dimensional Hooke's laws for plate material. The theory represents a more realistic quadratic variation of the transverse shearing strains and linear variation of the transverse normal strains through the plate thickness. A special mass matrix diagonalization scheme is adopted which conserves the total mass of the element and includes the effects due to rotary inertia terms. The results presented should be useful in obtaining better correlation between theory and experiment, and to numerical analysts in verifying their results. 相似文献
Furosemide-loaded calcium alginate (ALG), calcium alginate-polyethyleneimine (ALG-PEI) and alginate-coated ALG-PEI (ALG-PEI-ALG) beads were prepared by ionotropic/polyelectrolyte complexation method to achieve controlled release of the drug. Effects of several formulation factors on the characteristics of the beads were investigated. Although variation in formulation factors did not influence the drug-loading efficiency (DLE) of ALG beads, rapid release of the drug in simulated intestinal fluid (SIF) could not be prevented. PEI treatment of ALG beads, however, prolonged the drug release considerably. Ionic interaction, as appeared from FTIR studies, between alginate and PEI led to the formation of polyelectrolyte complex membrane, the thickness of which was dependent on the conditions of PEI treatment as demonstrated by scanning electron microscopy (SEM). The membrane acted as a physical barrier to drug release from ALG-PEI beads. Alginate coating of ALG-PEI beads further prolonged the release of the drug by increasing membrane thickness and reducing swelling of the beads possibly by blocking the surface pores. Differential scanning calorimetry (DSC) study indicated that drug was not degraded by PEI treatment. The release data from ALG-PEI beads showed a good fit in power law expression, whereas the release data from ALG-PEI-ALG beads were found to fit in modified power law expression, and the mechanism of drug release changed from super case II transport to nearly Fickian transport, depending on the degree of gelation and formation of polyelectrolyte complex membrane. 相似文献
Computer-aided process planning (CAPP) forms an important interface between Computer-aided design (CAD) and Computer-aided
manufacturing (CAM). It is concerned with determining the sequence of individual manufacturing operations required to produce
a product as per technical specifications given in the part drawing. Any sequence of manufacturing operations that is generated
in a process plan cannot be the best possible sequence every time in a changing production environment. As the complexity
of the product increases, the number of feasible sequences increases exponentially, and there is a need to choose the best
among them. This paper presents an application of a newly developed metaheuristic called the ant colony algorithm as a global
search technique for the quick identification of the optimal operations sequence by considering various feasibility constrains.
A couple of case studies are taken from the literature to comparing the results obtained by the proposed method. 相似文献
At present, with the advances in satellite communication systems and their increasing importance, wideband antennas are in great demand for both military and commercial applications. Most of the communication systems need a wideband antenna that operates on multi-octave frequencies. In patch antenna, diverse techniques played a vital role in enhancing the antenna parameters such as gain or bandwidth. A new design concept of a compact rectangular dual patch antenna has been developed for both high gain and wider bandwidth. In this work, a compact rectangular dual patch antenna is proposed as a wideband antenna for multiple satellite communication applications such as Global Positioning System, Global Navigation Satellite System, Indian Regional Navigation Satellite System, and S-Band Satellite Communication. The designed rectangular dual patch antenna is simulated and fabricated. Based on the performance, the fabricated antenna is compared with the simulated results in terms of VSWR, gain, axial ratio, and 3 dB beam width. Increased gain and wider bandwidth have been achieved with the developed rectangular patches and their energy distributed on the surface of the dual patches simultaneously. Finally, the proposed rectangular dual patch antenna shows improved performance for the multiple satellite communication applications.
Modern communication systems employ wideband antennas with circular polarization (CP) radiation. In this work, asymmetric modified bow-tie (ABT) and symmetric modified bow-tie (SBT) slotted circularly polarized single-point probe-fed circular patch antennas with dimensions of 40 mm × 40 mm for wideband applications are proposed. A 10 dB RL bandwidth of 350 MHz with CP, 3 dB axial ratio (AR) bandwidth of 100 MHz, peak gain of 4.9 dBic, and 10 dB RL bandwidth of 530 MHz with CP, 3 dB AR bandwidth of 140 MHz, peak gain of 5 dBic are obtained for ABT and SBT slotted circular patch antennas, respectively. The proposed SBT slotted patch is scaled up and down to 50 mm × 50 mm and 30 mm × 30 mm, respectively. The proposed scaled-up version offers 10 dB RL and 3 dB AR bandwidths of 340 MHz and 80 MHz, with a peak gain of 5 dBic. The scaled-down version offers 10 dB RL and 3 dB AR bandwidths of 710 MHz and 180 MHz, with a peak gain of 5.25 dBic. These prototypes are suitable to work in IEEE 802.11a WLAN, ISM, and IEEE 802.11ac applications. The measured and simulated results are then discussed and compared. 相似文献