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Wind turbines are widely used for conversion of the wind power into mechanical energy. The failure of the blade during operation is a common phenomenon which can lead to the degradation of the power output. Modeling and analysis of wind turbine blade is critical for the design and safe and efficient operation. In this study, a one-way coupled Finite Element (FE) scale model of RM1 SAFL turbine is developed to simulate structural integrity and deformations in the blades. The study is primarily focusses on the strength and deformation of the blades under varying wind speeds ranging from 5 m/s to 30 m/s. The wind turbine blades were modelled from aluminum alloy and unidirectional carbon reinforced composite (epoxy carbon). The results obtained from numerical simulation demonstrated higher stresses and blade tip deformation in blades from composite compared to aluminum AL 6061 alloy. Maximum displacements were calculated at the tip of blades and were well under the threshold level. The maximum stress intensity was found in the center of the blades. On the basis of the current geometry, modal analysis of turbine blades was performed and benchmark cases for the dynamic response were investigated. The natural frequency for aluminum alloy was calculated to be almost three time higher than of composite material structure. The modal in case of composite material was approximately 35% of that obtained using aluminum alloy. This study suggests further analysis to predict surface integrity of the turbine blades under more volatile wind conditions

This paper presents the results of hydrodynamic performance and wake assessment for a horizontal axis tidal current turbine. The three-dimensional instantaneous flow field is resolved utilizing the Improved Delayed Detached Eddy Simulation (IDDES) turbulence model and polyhedral mesh. The rotor rotation is simulated by employing the sliding mesh approach. The simulation results using turbulence model of k-ω Shear Stress Transport are also presented for comparison. The simulated thrust and power coefficients and wake characteristics are validated against published experimental results. It is shown that the performance and wake velocity predicted by IDDES are closer to the experimental values than those predicted by k-ω Shear Stress Transport model. In determining the pressure coefficient, only IDDES captures the time-varying fluctuations pertaining to blade generated turbulence. The oscillations in phase-averaged performance coefficients are substantially larger for IDDES because the inflow turbulence in this model is more realistically resolved using Synthetic Eddy Method. The IDDES predicts more detailed vortex structures which has impact on accurate determination of blade pressure distribution and also energy dissipation rate and downstream flow field. It is demonstrated that the IDDES model is capable to satisfactorily simulate the hydrodynamics of a horizontal axis tidal current turbine.

In this study, the ballistic impact behavior of auxetic sandwich composite human body armor was analyzed using finite element analysis. The auxetic core of the armor was composed of discrete re-entrant unit cells. The sandwich armor structure consisted of a front panel of aluminum alloy (Al 7075-T6), UHMWPE (sandwich core), and a back facet of silicon carbide (SiC) bonded together with epoxy resin. Numerical simulations were run on Explicit Dynamics/Autodyne 3-D code. Various projectile velocities with the same boundary conditions were used to predict the auxetic armor response. These results were compared with those of conventional monolithic body armor. The results showed improved indentation resistance with the auxetic armor. Deformation in auxetic armor was observed greater for each of the cases when compared to the monolithic armor, due to higher energy absorption. The elastic energy dissipation results in the lower indentation in an auxetic armor. The armor can be used safely up to 400 m/s; being used at higher velocities significantly reduced the threat level. Conversely, the conventional monolithic modal does not allow the projectile to pass through at a velocity below 300 m/s; however, the back face becomes severely damaged at 200 m/s. At a velocity of 400 m/s, the front facet of auxetic armor was destroyed; however, the back facet was completely safe, while the monolithic panel did not withstand this velocity and was completely damaged. The results are encouraging in terms of resistance offered by the newly adopted auxetic armor compared to conventional monolithic armor.

Composites have played a vital role ranging in the marine structures to agriculutural products. Therefore, proper attention should be given before deploying of composite structures in the service and vibration is one of the most critical factor in the assessment of the structural properties. The purpose of this paper is to review the literature studies on the effect of vibration on composite structures. The literature studies have been focused on the vibration analysis of composite structures without considering the crack or delamination presence in the structure. Literature review is further classified on the basis of methodology i.e experimental, analytical and finite element methods. The work already conducted using these three methods have been discussed. It would be concluded that the vibration is a critical factor to focus.

The focus of this paper is to investigate the effect of velocity shear on the performance and structural response of a turbine using ANSYS Workbench. CFD simulations are performed for a small-scale threebladed horizontal axis turbine in a uniform and velocity shear environment. The turbine diameter is 0.28 m and operates in a free stream velocity of 0.5 m/s. The steady state and transient CFD analysis results are validated with published data. Results for the turbine performance coefficients from the steady state and transient CFD analysis differed by 3% and 1.2%, respectively, from the previously published data. One-way FSI analysis is carried out in ANSYS Workbench by connecting ANSYS CFX and ANSYS static structural analysis systems to evaluate the effect of velocity shear on blades’ equivalent stress and deformation. For the FSI analysis, the steady state solution data are transferred and mapped at FEA mesh locations using ANSYS CFD-Post mapping. Results from the FSI analysis show that deformation of the turbine blades increases in a velocity shear environment compared to uniform flow.

ECAP (Equal Channel Angular Pressing) is a technique used to enhance the strength of material by grain refinement. In this research, an aerospace grade aluminum alloy-6061 is investigated. The specimens were pressed through ECAP die channels, intersecting each other at an angle of 90oC where a shear plane of 45oC was developed, that results grains refinement. Fatigue strengths and CGR (Crack Growth Rate) for the stress ratio R 0.7 and 0.1 are found and compared with the as-received material.It was observed that the CGR is slower at stress ratio R=0.1, as compared to stress ration R=0.7. An electric furnace was embedded with ECAP die to regulate the material flow through this die. The temperature of the die was maintained at 450oC during ECAP pressing and the specimens were also preheated at this temperature using another furnace. The ECAP die consists of two channels intersecting at 90o provided with safe inner and outer corner radius to avoid scaling.The microstructural observations revealed that the deformation was perfectly plastic. The ECAPed and as-received materials were also characterized by tensile tests, micro-hardness tests, and 3-point bend fatigue tests.

The effects of blockage ratio and boundary proximity on tidal turbine performance are quantified in this study using computational fluid dynamics (CFD). Reynold averaged Navier–Stokes (RANS) equations are solved using the commercial CFD code ANSYS CFX. Steady-state analyses are performed using a rotating frame of reference technique, and a shear stress transport turbulence model is used. Results from the numerical model are validated with experimental data. RANS CFD simulations are performed over tip speed ratios (TSRs) from 1 to 9. The simulation-based performance curve approximately match the experimental performance curve, with errors ranging from 4 to 9%. Blockage ratios from 0.02 to 0.19 are evaluated for a constant depth of two rotor diameters to study the effect of blockage on turbine performance. Results show that shaft power increased by 13 and 47% for TSRs of 5.11 and 9.05, respectively, when the blockage ratio increased from 0.02 to 0.19. Additionally, for these TSRs and blockage ratios the turbine thrust increased by 7 and 10%. The presence of a boundary layer resulted in a calculated thrust increases between 1.6 and 2.3% and power between 2.7 and 3.5% for the entire range of evaluated blockage ratios.

Implants are widely used in the human body for the replacement of affected bones. Fatigue failure is one of the serious concerns for implants. Therefore, understanding of the underlying mechanism leading to fatigue failure is important for the longevity of biomaterial implants. In this paper, the fracture toughness and fatigue crack growth of titanium alloy biomaterial Ti-27Nb has been experimentally investigated. The Ti-27Nb material is tested for fatigue crack growth in different environmental conditions representing the ambient and in vitro environments for 504 hours and 816 hours, respectively. Fractography of the tested specimen is conducted using Scanning Electron Microscope (SEM). The results of the fatigue crack growth propagation of the ambient and in vitro samples are similar in the Paris crack growth region. However, in the threshold region, the crack growth rate is higher for the Simulated Body Fluid (SBF) treated specimen. The fracture surface morphology of in vitro samples shows brittle fracture as compared to ambient specimens with significant plasticity and striations marks. It is proposed that a similar investigation may be conducted with specimens treated in SBF for prolonged periods to further ascertain the findings of this study.

A series of zinc substituted cobalt ferrite samples i.e., Co1-xZnxFe2O4 (x = 0.0–0.6) were synthesized by sol-gel method. X-ray diffraction patterns confirmed the formation of pure-phase cubic spinel structure in the prepared samples. Cation distribution between the tetrahedral and octahedral sites were estimated by refining the XRD patterns by Rietveld method. Magnetic studies revealed that the saturation magnetization is maximum for x = 0.4 sample; whereas the values of coercivity, magnetic anisotropy constant and magnetostriction decreased with increasing x. However, a considerable enhancement in the magnitude of strain sensitivity is obtained for x = 0.4 sample in comparison to other substituted samples. The observed variations in the magnetic results are discussed on the basis of site occupancies of the cations and decreased anisotropy of the prepared samples whereas the microstructure plays insignificant role. Moreover, the dielectric measurements indicated a reasonable value of dielectric constant at low frequencies along with a low value of ac conductivity for x = 0.4 sample due to electron–hole compensation at octahedral sites of the spinel structure. Here, it is suggested that x = 0.4 composition exhibits the optimal magnetic and dielectric properties in the Co1-xZnxFe2O4 system that could make this composition as a potential candidate for stress sensor applications.

Polytetrafluoroethylene (PTFE) was coated on 316L stainless steel (SS) substrate through a spin coating technique to enhance its corrosion resistance properties in hydrochloric acid (HCl) and nitric acid (HNO3) medium. Scanning electron microscopy (SEM) revealed the morphology of the coated and uncoated substrates and showed a uniform and crack-free PTFE coating on 316L SS substrate, while a damaged surface with thick corrosive layers was observed after the electrochemical test on the uncoated sample. However, an increased concentration of HCl and HNO3 slightly affected the surface morphology by covering the corrosive pits. An atomic force microscope (AFM) showed that the average surface roughness on 316L SS and PTFE coating was 26.3 nm and 24.1 nm, respectively. Energy dispersive X-ray spectroscopy (EDS) was used for the compositional analysis, which confirmed the presence of PTFE coating. The micro Vickers hardness test was used to estimate the hardness of 316L SS and PTFE-coated substrate, while the scratch test was used to study the adhesion properties of PTFE coating on 316L SS. The anticorrosion measurements of 316L SS and PTFE-coated substrates were made in various HCl and HNO3 solutions by using the electrochemical corrosion test. A comparison of the corrosion performance of PTFE-coated substrate with that of bare 316L SS substrate in HCl medium showed a protection efficiency (PE) of 96.7%, and in the case of HNO3 medium, the PE was 99.02%, by slightly shifting the corrosion potential of the coated sample towards the anodic direction.

Vibrations are usually induced in aero engines under their normal operating conditions. Therefore, it is necessary to predict the critical frequencies of the rotating components carefully. Blade deformation of a jet engine under its normal operating conditions due to fatigue or bird strike is a realistic possibility. This puts the deformed blade as one of the major safety concerns in commercially operating civil aviation. A bird strike introduces unbalanced forces and non-linearities into the engine rotor system. Such dynamic behavior is a primary cause of catastrophic failures. The introduction of unbalanced forces due to a deformed blade, as a result of a bird strike, can change the critical frequency behavior of engine rotor systems. Therefore, it is necessary to predict their critical frequencies and dynamic behavior carefully. The simplified approach of the one-dimensional and two-dimensional elements can be used to predict critical frequencies and critical mode shapes in many cases, but the use of three-dimensional elements is the best method to achieve the goals of a modal analysis. This research explores the effect of a bird strike on the critical frequencies of an engine rotor. The changes in critical mode shapes and critical frequencies as a result of a bird strike on an engine blade are studied in this research. Commercially available analysis software ANSYS version 18.2 is used in this study. In order to account for the material nonlinearities, a Johnson Cook material model is used for the fan blades and an isotropic&ndash, elastic&ndash, plastic&ndash, hydrodynamic material model is used for modeling the bird. The bird strike event is analyzed using Eularian and smoothed particle hydrodynamics (SPH) techniques. A difference of 0.1% is noted in the results of both techniques. In the modal analysis simulation of the engine rotor before and after the bird strike event, the critical failure modes remain same. However, a change in the critical frequencies of the modes is observed. An increase in the critical frequencies and excitation RPMs (revolution per minute) of each mode are observed. As the mode order is increased, the higher the rise in critical frequency and excitation RPMs. Also, a change in the whirl direction of the different modes is noted.

The current paper describes the effect of insulation thickness in a vacuum resistance furnace. An existing furnace was optimized for insulation thickness using analytical and numerical studies. Furnace heating efficiency was improved up to 64% by controlling the heat flow at the insulation face. The numerical results were validated experimentally and vice versa. The numerical results predicted a decrease in heat flow of 70%, while the experimentally achieved value was 64%. The percentage difference in numerical and experimental results was calculated to be 1.5&ndash, 5% maximum in temperature value. The effect of mesh finesse was evaluated for thermal analysis and it was concluded that a very little difference of 5 &deg, C occurs when element size is reduced 5 times. The study using numerical methods will help in designing better and upgraded furnaces with greater energy savings. Also, the application of numerical methods is proposed as an effective design and performance prediction tool during manufacturing and operational activities of vacuum furnaces, respectively.

The vibration of the delaminated composites concerns the structure safety and dynamic behavior of the composite structures as it can be vital in the presence of delamination. In this research paper, the finite element simulations, numerical simulations and the experimental work are combined to analyze the vibration behavior at different delamination size, different stacking sequences and different boundary conditions. The finite element analysis software packages like Ansy and Abqus are used to fetch the vibration response of carbon fiber reinforced polymer composite plate for different boundary conditions, stacking sequences and delamination sizes. Experiments are carried out to study the vibration behavior. Numerical results were obtained using the first order shear deformation theory. Rayleigh-Ritz method was used to derive the governing equations to find the natural frequencies and the results were computed using Matlab tool. The results from finite element, numerical and experimental analysis were then compared and verified that the maximum percentage of error is ignorable. It is seen that the natural frequencies of carbon fiber reinforced polymer decreased with an increase in delamination size subjected to all boundary conditions. The higher values of natural frequencies found for all sides clamped boundary conditions.

Wire ropes undergo a fretting fatigue condition when subjected to axial and bending loads. The fretting behavior of wires are classified as line contact and trellis point of contact. The experimental study on the fatigue of wire ropes indicates that most of the failure occurs due to high localized stresses at trellis point of contact. A continuum damage mechanics approach was previously proposed to estimate the fatigue life estimation of wire ropes. The approach majorly depends on the high value of localized stresses as well as the micro-slippage occurs at the contact region. Finite element approach has been used to study radial and axial distribution of stresses and displacement in order to clearly understand the evolution of stresses and existence of relative displacements between neighboring wires under various loading and frictional conditions. The relative movements of contacting wires are more when friction is not considered. In the presence of friction, the relative movement occurs at the boundaries of the contact region. The location of microslip in the presence of friction is backed by the experimental observation stating the crack is initiated at or the outer boundary of the contact spot. The existence of slip is due to different displacement of outer and central wires.

This paper presents the results of a Computational Fluid Dynamics (CFD) model of a two rotors operating in close proximity. The main purpose was to obtain a validated CFD model of scaled twin rotor laboratory turbine and to model how the wake of these two rotors will affect the performance of individual and collective turbines in future array. The results of numerical methods such as CFD are dependent upon selection of mesh size, length of domain to capture the wake and turbulence model. In this paper steady state RANS CFD simulations were performed by utilizing a Rotating Frame of Reference (RFR) model and shear stress transport (SST) closure model for single, Twin rotor, different domain length and mesh sizes. The obtained results were compared with experimental data. Single rotor performance closely resembles the experimental data while that of twin rotor showed a deviation. With changing of domain length and mesh size the performance became close to the experiment but the wake was quite different showing the limitations of utilized turbulence model.

The design of support structures requires precise knowledge about the effect of support tower on turbine performance, loads and its fatigue character. Therefore, a tidal current turbine mounted on an elastic tubular monopile support tower is simulated in coupled Fluid Structure Interaction (FSI) simulations using ANSYS Workbench. The performance and behavior of turbine loads for an elastic tower is compared with rigid tower for similar case. The tower elasticity has significantly increased the variation in power coefficient from 2.61% to 3.5% and thrust coefficient from 1.4% to 2.2% compared to a similar turbine mounted on a rigid tower. Although, the tower elasticity has minimal impact on the overall power output but greatly affect the quality of power output due to increased variation in power coefficient. Direct thrust force on the tower varies by about 120% and 104% while the total thrust force varies by 4.8% and 3.8% from mean cycle value for the elastic and rigid tower case respectively. Stress life fatigue analysis of steel tubular monopile support tower show that the support tower has a minimum fatigue factor of safety of 1.32 and fatigue life of 37.8 years for a design life of 20 years. This suggest that steel tubular structures according to the available manufacturer guide lines, would sustain the fatigue load cycles and may be adequate for use as a support tower to a tidal current turbine.

The outcome of Numerical methods such as Computational Fluid Dynamics (CFD) based on Reynolds Averaged Navier Stokes (RANS) is dependent upon selection of several critical parameters. The effect of boundary conditions, boundary flow modelling and turbulence numerics has been quantified in this study. Steady state RANS CFD simulation are performed by utilizing a Rotating Frame of Reference (RFR) model along with a Shear Stress Transport (SST) closure model. The simulated performance results were compared with experimental data over Tip Speed Ratios (TSR) from 2-9. Four different sets of boundary conditions that can possibly represent an experimental water channel were evaluated. The variation of boundary condition resulted in the variation of prediction error at different TSR’s. Critical variations were observed at the extreme operating conditions of minimum and maximum TSR’s. However, the C P prediction error at the optimum TSR was not much affected by the variation of boundary conditions.

Vibration and acoustic emission have received great attention of the research community for condition-based maintenance in rotating machinery. Several signal processing algorithms were either developed or used efficiently to detect and classify faults in bearings and gears. These signals are recorded, using sensors like tachometer or accelerometer, connected directly or mounted very close to the system under observation. This is not a feasible option in case of complex machinery and/or temperature and humidity. Therefore, it is required to sense the signals remotely, in order to reduce installation and maintenance cost. However, its installation far away from the intended device may pollute the required signal with other unwanted signals. In an attempt to address these issues, sound signal-based fault detection and classification in rotating bearings is presented. In this research work, audible sound of machine under test is captured using a single microphone and different statistical, spectral and spectro-temporal features are extracted. The selected features are then analyzed using different machine learning techniques, such as K-nearest neighbor (KNN) classifier, support vector machine (SVM), kernel liner discriminant analysis (KLDA) and sparse discriminant analysis (SDA). Simulation results show successful classification of faults into ball fault, inner and outer race faults. Best results were achieved using the KLDA followed by SDA, KNN and SVM. As far as features are concerned, the average FFT outperformed all the other features, followed by average PSD, RMS values of PSD, PSD and STFT. Refereed/Peer-reviewed

This paper describes structural analysis of a large composite wind turbine blade under extreme loading. These extreme loading can cause damage and significant drop in the load-carrying ability of large composite wind turbine blades. Therefore, it is vital to investigate the structural strength of the blades for their safe operation during its life time. In this study first, a three-dimensional (3D) surface model of the blade is generated using NuMAD (Numerical Manufacturing and Design), which greatly simplifies the 3D model generation of a wind turbine blade, and effectively handles all information of blade airfoils, material properties and their geometrical configuration. The blade model is then evaluated for its ability to withstand the extreme loading conditions as specified in the relevant standards using finite element analysis (FEA) software ANSYS. Results show that the stresses and deformation in all parts except shear webs are within the design limits specified by standards. The higher stress level in shear web can be minimized by increasing the number of number of biaxial plies. Further, the structural weight of the blade is comparable to other blades of similar rated powers. Furthermore, optimizing the blade geometry and airfoil as well as ply layup especially in spar caps, and changing position of shear webs can have a profound effect on the overall performance and structural integrity of the blade.

A power free solar tracking system has been developed. The proposed system is suitable for 6 hours of continuous cooking. The system altitude has been fixed which avoids changing the system angle for different seasons. The azimuth angle has changed through the gravitational potential energy stored in a water container. The water container is connected to a pair of springs. Discharge of water from the container at a consistent predetermined charge drives the timing belt. The timing belt was established on semi-circular bar of Scheffler cooker. This mechanism allows the Scheffler cooker to rotate with the sun at a uniform rate.

The bone auto grafting, isografting, allografting and xenografting are used for defective bone replacement or treatment in almost all living species. The X-ray and Gamma (electromagnetic radiation) sterilization performed on the donor bone graft to prevent toxicity or migration of virus/bacterial infections from donors to reciver. Conversely, X-ray and Gamma radiation deteriorates the bone mechanical properties and bone become more susceptible to fracture. Fracture toughness as well as other mechanical properties of bone change with these radiations. In this literature review the effect of the X-rays and Gamma radiation on bone mechanical properties are discussed. All relevant literature was reviewed. After reviewing the literature only the research relating to the effect of X-rays and Gamma radiations on bone mechanical properties are included. Literature studies showed significant effect of the X-rays and Gamma radiations on the mechanical properties of the bones. In some studies the differences exists on the doses of radiations which were discussed in this study. The high energetic electromagnetic radiation (X-rays and Gamma radiations) changed/modify the collagen network of the bone, which reduced the mechanical properties of bone; however these changes depend on the radiation dose.

The studies reported in the literature on the effect of stress ratio or mean stress on fatigue delamination growth in composites are critically reviewed in this paper. These studies are classified according to their mode of fracture. Majority of the studies lack a mechanistic approach to the delamination growth characterization and the effect of stress ratio. The researchers are divided in the use of a unified correlating parameter for the delamination growth. The mechanisms of fatigue crack growth in metals are often extended to the delamination growth characterization.

The purpose of this research is to study in detail about the site selection process in nuclear power plant (NPP) construction. There are various factors that contribute to the site selection which involves in-depth investigation and detailed evaluation before the site is being finalized and proposed. There are two main objectives in siting of NPP; ensuring the technical and economic feasibility of the plant and minimising potential adverse impacts on the community and environment. Geographical environment also plays an important role in siting of NPP where the source of water should be abundance. Country requirement for siting of NPP would be different for every country where they are controlled by their own regulatory bodies. About 64 published studies (1967-2017) are reviewed in this paper. It is marked from the literature survey articles that siting process is extremely crucial step in constructing NPP where public acceptance is one of the main factors, that need to be considered. Malaysia is one of the new countries embark in nuclear industry that still is in the planning phase to plan and construct its first NPP.

Over 493 million people in south Asia and more than 1.5 billion worldwide have no access to the electricity. Unfortunately in Pakistan the power sector is facing severe energy crisis due to shortage in power generation and increase in load demand at the rate of about 10% each year. One of the main reasons is greater dependency on traditional energy sources like fossil fuels and hydroelectricity. The rural electrification is a big challenge in Baluchistan province due to dispersed load and high distance location of grids from the load centers. Rural electrification in most developing countries is now carried out with available renewable resources potential. In Baluchistan both solar and wind energy is available in abundant. In this research work both resources with other option of local coal and LPG (non-renewable) is presented to electrify the remote areas. The work illustrates the overview of power sector, total available renewable energy sources and optimal utilization of these forces at remote regions. The final analysis provides the potential based renewable energy implementation in rural areas of province.

This Paper discussed the historical review, current status of ocean current turbine, challenges and problems in the way of the ocean current turbine commercialization. As we known that fossil fuel resources in the world are limited and we can't depend on them for the future energy needs of the world. For this purpose the researcher have find such sources of energy which are sustainable, green, environment friendly and have no impact on human lives, which includes renewable energy sources like solar, wind, and ocean energy sources. In this review paper, we also focused on the initiative of the ocean current energy technology and the efforts of different countries, companies and scientist for the development of ocean current turbine to extract power from ocean current energy including Marin Current Turbine Ltd (MCT), Florida Atlantic University (FAU). We summarized the current status and recent development in the field of ocean current turbine. We discussed some earlier projects and prototypes. The paper also discusses the impact of the ocean current turbine on the environment and marine life. Some of the current limitation and problems are also identified in the way of ocean current turbine development like grid connection.

Free vibration analysis of aluminum foam sample is performed in the present paper. Mechanical properties of metal- lic foams depend on their relative densities. The discrete mass distribution of metallic foam causes discontinuities in their local properties. X-ray computer tomography (XCT) revealed the 3-D inhomogeneous mass distribution in metallic foams. The densi- ty mapping method is used to approximate the aluminum foam trade name ALPORAS by a continuous, 3-D density distribu- tion at the mesolevel. The density recorded by XCT is homogenized over an averaging volume. A continuum model is imple- mented using the finite element (FE) method to simulate the effect of local mass distribution on the modal behavior of metallic foam sample. The effect of measured density distributed model (MDDM) Coarse sub-domain density model (CSDM), uniform average density model (UADM), and three random distributed density model (RDDM) on eigen frequencies of the aluminum foam sample is studied. Density distribution of aluminum foam measured by X-ray computer tomography was used as input to the corresponding FE model of investigated specimen. All numerical investigations were carried out by means of the FE pack- age ANSYS.

The objective of this study endeavor is to describe the design of an environment friendly captive micro hydel power plant at the sewerage treatment plant outlet fall at Lai Nallah located in I-9 Islamabad. It will use sewerage water of CDA as discharge water to run the turbine of the micro hydel power plant to generate electricity. The important phases of the project are to carry out survey for collection of data about hydrology, quantity of flow of water, fall head, geology and design of an efficient turbine. Complete design calculations of turbine have been performed along with static and model analysis of the turbine. Key parameters to increase efficiency of cross-flow turbine are discussed.

Energy use for domestic purposes can be considered as the prime consumer ofPakistan’s energy resources. Residential buildings are one of the consumers of energyfor space cooling. In this paper we studied the energy consumption for space coolingof a residential building for located in Islamabad. The relevant data of construction,operation schedules, occupancy and lighting of the selected residential building wascollected and analyzed through simulation using eQuest energy simulation tool. Themodel was considered as the baseline model for further analysis. Energy efficiencymeasures were applied to windows area, windows glazing type, Area lighting, heatingventilating and air conditioning (HVAC) system thermostat set point and EnergyEfficiency ratio of the HVAC system. Results showed 38.5 % decrease in the energyconsumption as compared to the baseline model.

Cu-doped ZnO nanorods have been synthesized by a low temperature, simple, fast and versatile fabrication approach. The prepared nanorods have average length and diameter of 500 nm and 40 nm, respectively. The structural and vibrational investigations depict that the prepared nanorods are in a single hexagonal phase and preferably grown along the c-axis. The X-rays photoelectron spectroscopy reveals that Cu is in 2+ oxidation state and doped up to 3% into the ZnO lattice. The magnetic measurements of doped nanorods show diamagnetic behavior at room temperature and paramagnetism at 8 K. The photoluminescence study shows that there is a considerable red-shift in the optical band-gap with Cu doping into ZnO and it exhibits improved luminescence properties. This tuned band-gap makes this a potential material for use in photo-catalysis, optoelectronics and solar-cell nanodevices.

Electricity is the backbone of economic stature of every country in current era. Many different ways have been devised to produce electricity and this exploration is still not seeing its end. But efficient Transmission and Distribution (T&D) of power is always a headache for supply companies especially in countries like Pakistan where short fall of electric power is already being faced. This paper shows percentage T&D losses by various electric supply companies of Pakistan, comparison of overall T&D losses of Pakistan with various countries of South Asia, Middle East, Europe, Africa etc and reasons for such high T&D losses. Short and long term measures for reducing these T&D losses of Pakistan.

The office buildings are main consumers of energy for space cooling in Pakistan. In this study a three storied office building was selected for studying the energy consumption. The data was collected from the se- lected building and was entered to eQuest software proram for simulation. This model was termed as baseline model. The building was further optimized with the windows area and glazing type separately. The results were compared with the baseline model. Simulation results showed that 10.5% of electrical energy used for cooling purposes can be saved by reducing the windows area. And up to 5% of the energy can be saved by using the double glazed brown tinted windows instead of single glazed windows.

This paper investigates the damage development ahead of mode I delamination tips in carbon /epoxy laminates using scanning electron microscope (SEM). Two techniques were adopted for the investigation; the first technique consisted of the application of stepwise load increments on DCB (double cantilever beam) specimens inside the SEM, while images were recorded until delamination onset. For the second technique, the DCB specimens were fatigue tested under different combinations of monotonic and cyclic loading. After the fatigue tests, the specimens were kept open in the microscope by insertion of steel wedges allowing the inspection of the delamination tips. The investigation revealed that multiple micro-cracks are formed parallel to the delamination growth direction ahead of the tip that coalesces. Micro-cracks that were formed 2 or 3 plies away from the delamination plane were observed to cause fibre bridging.

Four Bedroom detached house was selected for analysis of energy performance of residential buildings in Islamabad. The actual building was studied for the energy consumption by simulating in eQuest, the whole building energy simulation program. This served as Baseline model for the analysis. This building uses electrical energy for space cooling. Energy efficiency measures were applied to the building by optimizing the windows area and changing the glazing type. Results show that employing the selected windows area reduction measure can save up to 7.2 % electrical energy as compared to the baseline model while applying the double window glazing for the baseline window size pay back 5.9% electrical energy saving of the energy used for space cooling in comparison to the baseline model. Index Terms— Simulation, Building, energy, electrical energy, efficiency, Baseline, Energy efficient model