Faculty of Mechanical Engineering

In this paper three dimensional nonlinear finite element analysis is performed for the optimization of an overhead crane box girder for capacity (50~120ton) and span (10 ~ 32 m) for safe bending stress and deflection with minimum mass and volume. A customized optimization code is developed using interpolative relations and correction factors to achieve optimized results with and without considering industrial constraints. A cutting and welding plan is developed to provide a standard operating procedure for the manufacturing of the box girder. Bill of materials, box girder design dimensions, and cutting and welding lengths are recorded with considerable time saving. ABSTRAK: Kertas ini mengkaji tentang analisis tidak linear tiga dimensi unsur terhingga bagi mengoptimumkan kotak kren galang atas kepala bagi kapasiti (50 ~ 120 tan) dan pada kadar (10 ~ 32 m) bagi takat lentur selamat dan pesongan dengan jisim minimum dan isipadu. Kod optimum penyesuaian telah direka mengguna pakai kait...

In present learning, surface protection layer progression of a third-grade fluid (TGF) is examined. Fluid transport within the micro passage made by the firm bladehas beenpresented. Main system of equations of fluidity have been narrated and streamlined by means of lubrication approximation theory (LAT). Here, approximate solutions of velocity, pressure gradient, and coating depth have been presented. Results of coating and layer forming have been tabulated and discussed as well. It is observed that the transport properties of third-order fluid delivers an instrument to regulate flow velocity, pressure, and affect the final coated region.

This study presents the theoretical investigation of a roll-over thin layer formation under the lubrication approximation theory. The set of differential equations derived by lubrication approximation is solved by the optimal homotopy asymptotic method (OHAM) to obtain precise expressions for pressure and velocity gradients. Critical quantities such as velocity, pressure gradient, and coating layer depth are numerically estimated. The impact of parameters affecting the coating and layer formation is revealed in detail. Results indicate that the transport properties of the higher-grade fluid play an essential role in regulating velocity, pressure, and the final coated region. Moreover, couple stress effects on the properties of fluid particles to be coated on roller-surface have also been studied.

Next generation optical communication networks demand the use of the lower channel spacing and high input power in Wavelength Division Multiplexing (WDM) systems to achieve higher data rates. However, decreasing channel spacing and increasing input power create nonlinear effects including Four Wave Mixing (FWM). In this paper a method has been introduced in which alternative circular polarizers are used to change the polarization of input pulses into right and left handed polarized pulses before multiplexer which results in reduction of FWM. With the help of this technique we can completely eliminate FWM by optimizing optical network's parameters. Exhaustive set of simulations has been performed in Optisys and system's performance has been calculated.

In this article, Optimal Homotopy Asymptotic Method (OHAM) is used to approximate results of time-fractional order Fokker-Planck equations. In this work, 3rd order results obtained through OHAM are compared with the exact solutions. It was observed that results from OHAM have better convergence rate for time-fractional order Fokker-Planck equations. The solutions are plotted and the relative errors are tabulated.

Increase velocity in omnidirectional (INVELOX) is the wind power transporting system, which is suitable for providing the maximum wind energy for better maneuver of wind turbine. This venturi has innovative features that are accomplished for functioning the integrating multiple wind turbine generator system, capture the wind flow through the omnidirectional intake and speed-ups the flow across the venturi region that is release into ambient environment through diffuser. In this study, INVELOX model 1 and model 2 are designed for investigation of pressure and velocity contours. Power output of turbine depends on pressure and velocity of wind. The venturi section result specifies velocity and pressure drop of both models of INVELOX; velocity of model 1 and model 2 increases from 10.42 to 45.5 m/s, respectively. Pressure drops transpire in model 1 and model 2 which decrease from À1:722 3 10 1 and À6:938 3 10 2 Pa, respectively. Upstream velocities and power of wind after throat of venturi are deliberated. The second and third turbines provide the less potential as compare to first turbine power. It is concluded that the power produced using multistage wind turbine is higher.

We propose objective and robust measures for the purpose of classification of "vaginal vs. cesarean section" delivery by investigating temporal dynamics and complex interactions between fetal heart rate (FHR) and maternal uterine contraction (UC) recordings from cardiotocographic (CTG) traces. Multivariate extension of empirical mode decomposition (EMD) yields intrinsic scales embedded in UC-FHR recordings while also retaining inter-channel (UC-FHR) coupling at multiple scales. The mode alignment property of EMD results in the matched signal decomposition, in terms of frequency content, which paves the way for the selection of robust and objective time-frequency features for the problem at hand. Specifically, instantaneous amplitude and instantaneous frequency of multivariate intrinsic mode functions are utilized to construct a class of features which capture nonlinear and nonstationary interactions from UC-FHR recordings. The proposed features are fed to a variety of modern machine learning classifiers (decision tree, support vector machine, AdaBoost) to delineate vaginal and cesarean dynamics. We evaluate the performance of different classifiers on a real world dataset by investigating the following classifying measures: sensitivity, specificity, area under the ROC curve (AUC) and mean squared error (MSE). It is observed that under the application of all proposed 40 features AdaBoost classifier provides the best accuracy of 91.8% sensitivity, 95.5% specificity, 98% AUC, and 5% MSE. To conclude, the utilization of all proposed time-frequency features as input to machine learning classifiers can benefit clinical obstetric practitioners through a robust and automatic approach for the classification of fetus dynamics.

Nanoparticles are generally used to scatter and absorb solar radiations in nanofluid-based direct solar receivers to efficiently transport and store the heat. However, solar energy absorption in nanofluid can be enhanced by using differential materials and tuning nanofluid parameter. In this regard, theoretical investigations of unsteady homogeneous Hiemenz flow of an incompressible nanofluid having copper and silver nanoparticles over a porous wedge is carried out by using optimal homotopy asymptotic method (OHAM). Hence, a semi-analytical solver is applied to the transformed system to study the significance of magnetic field along with Prandtl number. In this work, impacts of conductive radiations, heat sink/source, unsteadiness, and flow parameters have been investigated for velocity and temperature profiles of copper and silver nanoparticles-based nanofluid. The effects of magnetic strength, volume fraction of nanoparticles, thermal conductivity, and flow parameters have also be...

The use of cutting fluids has played a vital role in machining operations in lubrication and cooling. Most cutting fluids are mineral oil-based products that are hazardous to the environment and the worker, cause severe diseases and pollute the environment. In addition, petroleum resources are becoming increasingly unsustainable. Due to environmental and health issues, legislations have been established to ensure that the consumption of mineral oil is reduced. Consequently, researchers are making efforts to replace these mineral oil-based products. Vegetable oils are grasping attention due to their better lubricating properties, ease of availability, biodegradability, low prices, and non-toxicity. In this study, a detailed review and critical analysis are conducted of the research works involving vegetable oils as cutting fluids keeping in view the shortcomings and possible solutions to overcome these drawbacks. The purpose of the review is to emphasise the benefits of vegetable oil...

In this paper vibration damping capacity of shape memory alloys (SMA) is studied which is based on two-dimensional Oberaigner, Fischer and Tanaka model. The thermodynamic based active and passive control paradigms in SMA are presented. The model solution is presented along with modification based on exact solution for the most general case of a set of conditions based upon general thermal regimes. For the particular cases, four examples of different thermal and mechanical loadings are given. This study incorporates the static thermal changes and dynamic thermal states.

In this paper vibration damping capacity of shape memory alloys (SMA) is studied, whose constitutive behavior is based on two dimensional Oberaigner, Fischer and Tanaka model (Oberaigner et al., 2002). The active and passive vibration damping paradigms of SMA with respect to thermal changes are touched here. In this work time-fractional order is given here. The above model solution is presented here for the most general case of a set of initial and boundary conditions which deal with generalized mechanical loadings and thermal regimes. For the particular cases, four examples for different thermal and mechanical loading-stresses, endorsed on the basis of fractional order with Homotopy Perturbation Method (HPM), are given. The solution given in this paper tells us how vibration response is studied with different thermal and different types of static and dynamic mechanical loading scenarios.

Surface electromagnetic waves are representation of Maxwell's frequency domain equations at the interface of two dissimilar materials. In this article, two canonical boundary value problems have been formulated to analyze the multiplicity of electromagnetic surface waves at the interface between two dissimilar materials. In the first problem, interface between two semi-infinite rugate filters having symmetric refractive index profiles is considered and in the second problem, to enhance the multiplicity of surface electromagnetic waves, a homogeneous dielectric slab is included between two semi-infinite symmetric rugate filters. Multiplicity has been observed by varying the size of dielectric material from 0 to 1000 nm. Numerical results show that the number of Tamm waves of different phase speeds, different polarization states, different degrees of localization, and different field profiles that are being propagated at interface between two semi-infinite rugate filters having symmetric refractive profile is almost twice as when asymmetric refractive index profile is used. Having two interfaces when a homogeneous dielectric layer is placed between two semi-infinite rugate filters has increased the multiplicity of electromagnetic surface waves.

made contributions to the development of ideas and their implementation the as well as conception of experiments on parallel octree method for the transient analysis. Shahab U. Ansari made substantial contributions to the conception of experiments on octree method for transient analysis. Tareq Manzoor contributed to the development of ideas and their implementation of conjugate method. Aijaz Ahmad made contributions to the data acquisition. Khurram Imran Khan made substantial contributions to the conception of experiments and data acquisition.

Moustafa Hussein Aly FWM Reduction Using Different Modulation Techniques and Optical Filters in DWDM Optical Communication Systems: A Comparative Study Next-generation optical communication networks require high input power and more number of channels at low spacing. This can be achieved using dense wavelength division multiplexing (DWDM). However, increasing the number of channels and decreasing channel spacing can enhance fiber nonlinearities, especially the four-wave mixing (FWM). In this paper, different modulation techniques and optical filters are considered and investigated to reduce the FWM effect in DWDM optical communication systems. System performance is evaluated through its quality factor (Q-factor), optical signal-to-noise ratio, optical received power and FWM efficiency. All used techniques have shown a reduction in FWM efficiency. The highest reduction in FWM efficiency is 25 dB and is reported while using modified Duobinary modulation with an increase of 2 in the Q-factor. A comparative study is carried out for the different techniques at 10-20 Gbps bit rate. All simulations are performed through Optisystem.

This paper presents a canonical boundary value problem to understand the behavior of electromagnetic surface waves propagated on the planar interface of rugate filter and hyperbolic material. The electromagnetic surface waves are generated on the planar interface of two different materials. The hyperbolic materials constructed by making a dyadic negative in columnar thin films. Multiple electromagnetic surface waves were investigated by varying phase of rugate filter form 0 to 180°and wavelength of incident light from 400 to 700 nm. Material's manufacturing fault is also introduced by adding 0.001 i in refractive index of hyperbolic medium.Propagation of multiple electromagnetic waves were observed on the planar interface of rugate filter and hyperbolic material. In order to verify the existence of surface electromagnetic waves at the interface of hyperbolic medium and rugate filter, electric and, magnetic fields are plotted for different material specifications.

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Nickel titanium (NiTi) shape memory alloys have a vigorous prospective for biomedical solicitations. In this work, electrochemical behavior of hydroxyapatite (HA) coated and thermally oxidized near equiatomic NiTi shape memory alloys was efficaciously investigated for biomedical applications. NiTi samples were spin-coated with laboratory-synthesized HA followed by drying and calcination at 120 ± 5°C and 450 ± 5°C, respectively. Similarly, uncoated NiTi samples were thermally oxidized by heating at 450 ± 5°C in air. The comparison was made among HA-coated, thermally oxidized and uncoated samples. Scanning electron microscope (SEM), atomic force microscope and X-ray diffraction confirm the presence of Titania and HA coating on the NiTi substrates. Electrochemical testing results showed the better resistance against corrosion for the HA-coated samples because of the protective coatings of HA and Titania, as compared to the rest. Moreover, Fourier transform infrared spectroscopy and SEM reveal that the HA-coated sample will provide bioactive cushion to the host structure for better adhesion during the implanted period, while the implant will do its job.