571 research outputs found
Development of a virtual reality milling machine for knowledge learning and skill training
No full textCurrent methods of training personnel on high cost machine tools involve the use of both classroom and hands on practical training. The practical training required the operation of costly equipment and the trainee has to be under close personnel supervision. The main aim of this project is to reduce the amount of practical training and its inherent cost, time, danger, personal injury risk and material requirements by utilising a virtual reality technology.
In this study, an investigation into the use of Virtual reality for training operators and students to use the Milling Machine was carried out. The investigation has been divided into two sections: first the development of Milling Machine in the 3D virtual environment, where the real machine was re-constructed in the virtual space.
This has been carried out by creating objects and assembling them together. The complete Milling machine was then properly modelled and rendered so it could be viewed from all viewpoints.
The second section was to add motion to the virtual world. The machine was made of functions as for the real machine. This was achieved by attaching Superscape Control Language (SCL) to the objects. The developed Milling machine allows the users to choose the material, speed and feed rate. Upon activation, the virtual machine will be simulated to carry out the machining process and instantaneous data on the machined part can be generated.
The results were satisfactory, the Milling Machine was modelled successfully and the machine was able to perform according to task set. Using the developed Virtual Model, the ability for training students and operators to use the Milling Machine has been achieved
Folio
No full textEducation SpecialEditorial. pp. v-vii; Profile-The Principal. pp. 1-2; Anwar M. Barkat-Article-The Goals of Education at F.C. pp. 3-8; Interview with Mr Abdul Hafeez Pirzada. pp. 9-15; Interview with Dr Abdul Khaliq. pp. 16-37; Interview with Dr Mohammad Ajmal. pp. 38-44; Interview with Dr Z. A. Hashmi. pp. 45-50; Interview with Dr (Miss) Kaneez F. Yousus. pp. 51-56; Anwar M. Barkat-Article-Asian University in the Perspective of Development and Modernization. pp. 57-61; Cyprian, Eric-Article-Thoughts on Education in Pakistan Today. pp. 62-63; Schlorholtz, A. A.-Attitude, Latitude, Gratitude. pp. 64-68; Sabeeh ur Rehman-Things I Want to Say. pp. 69-74; Mohammad Ahmed-Article-Need of Physical Education. pp. 75-77; Iqbal, M. Anwar-Teachers are Difficult for Students. pp. 78-80; Irteza Shah-Article-Education and its Place in our Society. pp. 81-83; Kaleem Omer-Poetry-Kashmir Diary. pp.84; Kaleem Omer-Poetry-Naming a Son. pp. 85; Akhar Tahir-Poetry-Fields. pp. 86; Akhar Tahir-Poetry-Album. pp. 87; Alamgir Hashmi-Poetry-Galillee. pp. 88-89; Alamgir Hashmi-Poetry-F.C.C. Bridge. pp. 90-91; Alamgir Hashmi-Poetry-By the F.C.C. Canal. pp. 92; Nasim Akhter-Poetry-A Visit. pp. 93; Naseer Ahmed-Poetry-In the Evening of Behrain. pp. 94; Naseer Ahmed-Poetry-How I Met My Father's Death. pp. 95; Danish Farhad-Poetry-The Misogynist. pp. 96; Irteza Shah-Poetry-My Love. pp. 97; Afsar Jahan-Poetry-For a Change. pp. 98; John Shaffaq-Poetry-Life. pp. 99; Ashtar Ausaf-Poetry-Apples Have Borrowed. pp. 99; Ashtar Ausaf-Poetry-Above the Trees. pp. 100; Agha Zulqarnain-Poetry-She is Dead. pp. 101; Irteza Shah-Story-Five Soldiers. pp. 102-104; Tahir Sarwar-Story-The Slave. pp. 105-110; Nazli Saleem-Story-The Sacrifice. pp. 111-113; Ghazala Anis-Story-Who Never Turned Up. pp. 114-117; Condolence: Dr E. M. Ewing. pp. 118; Condolence: Professor Z. Bede. pp. 119; Condolence: Gen Nasir-ud-Din. pp. 119; A Letter from Dr E. J. Sinclair. pp. 119; Iqbal Mirza-Dr E. J. Sinclair. pp. 120-122; Iqbal Mirza-Professor R. C. Thomas. pp. 123-125; Tahir Sarwar-Essay-A Visit to a Girls College. pp. 126-128; Haroon Omar-Essay-Man at Cross Roads. pp. 129-131; Abdul Mateen Khan-Essay-Food Crisis in Islamic Countries. pp. 132-133; Ghazala Anis-Essay-Human Happiness. pp. 134-136; Shahid Mahmood-Essay-Reverie. pp. 137-140; Shahid Ghafoor-Essay-Students and Politics. pp. 141-142; Professor Iqbal Mirza and Ashtar Ausef-F. C. Round Up. pp. 143-146; Contributors. pp. 147-148; Folio [Urdu] 128 p.Folio Editors. after contents; Dr Anwar M. Barkat, Principal. before page 1; Prof. Z. Bede (Late). after page 118; Dr R. M. Ewing (Late). after page 118; Prof. R. C. Thomas. after page 122; FCC: a survey (Cartoon). after page 146; Mualana Syed Farzand Ali. after page 8 (Urdu section); General Nasir Ali. after page 6 (Urdu section); Bazm-e-Adab 1973-74. before contents (Urdu section
Development of a hybrid genetic algorithm based decision support system for vehicle routing and scheduling in supply chain logistics managment
No full textVehicle Routing and Scheduling (VRS) constitute an important part of logistics management. Given the fact that the worldwide cost on physical distribution is evermore increasing, the global competition and the complex nature of logistics problems, one area, which determines the efficiency of all others, is the VRS activities. The application of Decision Support Systems (DSS) to assist logistics management with an efficient VRS could be of great benefit. Although the benefits of DSS in VRS are well documented, however in practice many organisations perform these activities manually using combination of skills, intuition and expertise.
A comprehensive review of literature revealed several drawbacks in the existing methods for addressing VRS. The traditional optimisation approaches have very limited applications and these require high computation time. Also, heuristic approaches are capable only to specific variation, a slight difference in the structure of the problem make the algorithm inefficient. Furthermore, metaheuristics methods require higher computation time and they are context dependent. Also, further investigations on the VRS problem formulations suggest that heuristic approaches usually address a single objective of distance minimisation. However in the real world there may be a number of conflicting objectives. In general, there is a lack of considerations for route selections, resource utilisation, unhlfilled demands, underused capacities, reliability of deliveries, fleet size, human fitness and operational cost. Also, these approaches fail to realise non-linearity within objectives and constraints defined for VRS problems. Furthermore, there are no clear distinctions between hard and soft constraints considered in these methods. Finally, the existing approaches fail to capture stochastic and dynamic nature of the logistics processes.
In order to overcome the above-mentioned drawbacks, this study designed and developed a hybrid DSS to assist logistics managers with VRS tasks. The capabilities of the developed DSS have then been applied to a Liquefied Petroleum Gas (LPG) distribution company. The architecture of this DSS is composed of Genetic Algorithm (GA) optimisation tool and a simulation model. The GA module aims to provide a pool of near optimum transportation schedules. The simulation module is used to further evaluate the generated schedules. The feed back from the simulation module is used to update the GA for reoptimisation. Some unique features of this DSS are such as: development of a multi modal genetic algorithm to address VRS problems; considering supply chain performance measures as part of VRS problem formulation; allowing consideration of different objectives, soft or hard constraints concerning the supply chain, considering linearlnonlinear relationships within objectives and constraints defined and finally, considering stochastic and dynamic behaviours of the supply chain system.
The GA and simulation tool integration provides unique benefits that have not been in the literature such as consideration of practical requirements, uncertainties, dynamic and stochastic behaviours, considering several criteria and producing different alternative solutions. Also, this integration allows the GA model to filter out solutions that are less competitive and therefore reducing the simulation time evaluation, which is computationally expensive. Furthermore, the human interaction with the system assists in generating higher quality of solutions. Finally, the clear benefit of this DSS is the fact that it greatly influences the applicability of the GA generated schedules and provides better confidence in implementation of these solution
sj-pdf-1-gsj-10.1177_21925682211058155 – Supplemental Material for Clinical Outcome of Coccygectomy Using a Paramedian Curvilinear Skin Incision in Adults and Children With Meta-Analysis of the Literature Focusing on Postoperative Wound Infection
No full textSupplemental Material, sj-pdf-1-gsj-10.1177_21925682211058155 for Clinical Outcome of Coccygectomy Using a Paramedian Curvilinear Skin Incision in Adults and Children With Meta-Analysis of the Literature Focusing on Postoperative Wound Infection by Satish Nagappa, Zeiad Alshameeri, Mohammad Elmajee, Yousuf Hashmi, Ajay Bowry, Morgan Jones, and Jonathan Spilsbury in Global Spine Journal</p
Experimental and finite element study of the hydroforming bi-layered tubular components
No full textThe application of finite element method (FEM) in the area of metal forming and material processing has been increasing rapidly during the recent years. The present study has been carried out on one of the unconventional metal forming processes called hydroforming of a multi-layered tube. The study involved both experimental and simulation work using FEA. Multi-layered tubes have extensive advantages in both domestic and industrial uses. The specimen tube consists of two different layers of materials. The outer tube material is brass and the inner tube material is copper. This project is mainly dedicated to the modelling, simulation and advanced study of one of the unconventional metal forming processes called hydroforming in which extremely high fluid pressure is used to deform the metal into desired shape. Various types of complex industrial products can be made by hydroforming. This process is suitable to produce seamless, lightweight, near net shaped industrial components. There are some complex products, which are easier to produce by hydroforming than by conventional technique.
In this research work the main forming load is hydrostatic pressure applied to the internal surface of the tube, together with an in-plane compressive load applied simultaneously. The blank is placed in a pre-shaped die block and due to the action of simultaneous internal pressure and axial load; it is formed into a complex desired shape. If the internal pressure is too high during the process without sufficient axial load it may cause the tube to burst, on the other hand too large axial load without applying sufficient internal pressure may cause wrinkling of the tube. For these reasons, a number of simulations of the hydroforming process have been carried out for different axial load and internal pressure combinations and optimum conditions have been established for the particular process. This simulated hydroforming of composite material tube and the formed product has been analysed on the basis of forming conditions and the simulated forming conditions have been verified by experiment. The simulations of hydroforming process for X or T branch have been carried by using the commercial finite element package ANSYS
Miriam Sampaio : Murmur
No full textThis publication stems from artist Sampaio’s residency at Centre de production Daïmõn in the fall of 2001. The resulting exhibition comprised photographs taken by the artist while in Portugal where she was researching her Judaic-Portuguese roots. Hashmi comments on this work in a personal and poetic text that includes many quotes from the artist. Texts in English and French. Biographical notes on artist and author. 2 bibl. ref
Performance-Based Intelligent Diagnostics, Prognostics, and Health Monitoring of Hydrogen Fueled Gas Turbines
No full textGlobal energy transition efforts towards decarbonization requires significant advances within the energy sector. In this regard, hydrogen is envisioned as a long-term alternative fuel for gas turbines. Accordingly, the gas turbine industry has expedited their efforts in developing 100% hydrogen compliant burners and associated auxiliary components for retrofitting the existing gas turbines. The utilization of hydrogen in gas turbines has some underlying challenges such as corrosion mainly originating from increased steam content in the hot gas path. In addition to corrosion, the gas turbine compressor is vulnerable to fouling, which is the most commonly occurring fault in gas turbine operating over certain time window. Both faults are susceptible to performance and health degradation. Owing to these problems, an in-depth thermodynamic performance assessment along with combustor’s flue gas thermophysical properties analysis becomes crucial. In addition to the thermodynamic performance model, performance-based intelligent fault diagnostics and prognostics/ remaining useful life (RUL) estimation of hydrogen fueled gas turbine is point of concern for the gas turbines original equipment manufacturers (OEMs) and operators.
The present thesis therefore addresses the above-mentioned technical challenges by providing a detailed comparative thermodynamic performance assessment of both hydrogen and natural gas (NG) fueled gas turbine scenarios. Besides, a comparative analysis of various artificial intelligence (AI) based approaches have been conducted for performance degradation estimation and fault diagnostics. Furthermore, to avoid expensive asset loss caused by unexpected downtimes and shutdowns, data-statistical prognostics have been employed for both NG and hydrogen fueled scenarios.
The first part of the thesis consists of thermodynamic performance and combustion flue gas analysis. The combustion reactions and detailed analysis of fluid flow properties manifested that H2 fuel utilization results
in an increased steam content (by ~106%) as compared to NG combustion. The combined effect of turbine corrosion severity level and high ambient temperature on the overall performance of the MGT showsthat the increased corrosion severity level at high ambient temperature can lead to deterioration in power and thermal efficiency. The second part deals with fault diagnostics using different machine learning based techniques. To identify an accurate algorithm, various algorithms such as support vector machine, decision tree, random forest algorithm, k-nearest neighbors, and artificial neural network were tested. The findings from fault diagnostics process (classification) revealed that ANN outperformed its counterpart algorithm by giving accuracy of 94.55%. Similarly, ANN also showed higher accuracy in performance degradation estimation process (regression) by showing the MSE of training loss as low as ~0.14. The comparative analysis of all the chosen algorithms in the present study revealed ANN as the most accurate algorithm for fault diagnostics of hydrogen fueled gas turbines. The last part dealt with prognostics/RUL estimation. In this regard, the study incorporated linear and polynomial regression approaches and compared the end of life of gas turbines running on natural gas and hydrogen fuels. It became evident from the study that RUL of a gas turbine running on hydrogen fuel is 6.47% lower than that of natural gas fueled gas turbines. These findings underline the necessity of using strong prediction models, as well as targeted maintenance actions, to limit the consequences of turbine corrosion in hydrogen powered MGTs. The findings of the present study further provide new horizons for design modification and effective health monitoring of hydrogen fueled gas turbines
Investigation into coatings produced from nanoparticle blended feedstock for rotating equipment repair applications
No full textCoating of carbon steel with conventional and nano particle blended feedstock material is considered in relation to repair applications of rotating equipment. Gas Metal Arc Welding (GMAW) and Wire Arc Spray (WAS) processes are used to produce the coatings on carbon steel workpieces. The wire arc sprayed workpieces are heat treated at temperature similar to the operating temperature of hot-path components of power gas turbines. The microstructure and metallurgy of the workpieces are examined using the Scanning Electron Microscope (SEM), Optical Microscope, Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD). The indentation tests are carried out to assess the microhardness variation across the coatings. In the case of coatings produced by GMAW, it is found that fine structures are formed in the coating due to the presence of nano particles and they resulted in increased microhardness of the coatings. In the case of the wire arc sprayed workpieces, the formation of dimples like structure at the surface increases the surface roughness of the coatings. In addition, the microhardness of the resulting coating is significantly higher than that of the base material. The heat treatment does not alter the microstructure and microhardness of the coatings significantly
Temporomandibular disorders in patients with mandibular fractures: A preliminary comparative case-control study between South Australia and Oman
No full textA. Al-Hashmi, A. Al-Azri, M. Al-Ismaily, A. N. Gos
Investigation into laser re-melting of inconel 625 HVOF coating blended with WC
No full textHigh velocity oxy-fuel (HVOF) spraying of Diamalloy 1005 powders mixed with WC particles onto steel (304) is considered and laser re-melting of the resulting coatings is examined. Laser re-melting process is modeled to determine the melt layer thickness while temperature increase is formulated using the Fourier heating law. The morphological and metallurgical analyses prior and post laser re-melting process are carried out using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). X-ray diffraction (XRD) technique is used to determine the residual stress developed in the coating while the analytical formulation is adopted to predict the residual stress levels at the coating base material interface. The indentation tests are carried out to determine the Young’s modulus and fracture toughness of the coating prior to laser re-melting. Corrosion resistance of coating is measured using potentiodynamic polarization technique prior and post laser treatment process. The predictions of the melt layer thickness are in good agreement with experimental results. The presence of WC particles modifies temperature rise and its gradient in the coating while affecting the Young’s modulus, residual stress levels, and fracture toughness of the coating. The differences in the thermal properties of Inconel 625 powders and WC particles result in formation of small size cellular structure through polyphase solidification. WC dissolution in the central region of the large polycrystalline cells is observed due to the loss of carbon through carbonic gas formation. The results of corrosion tests prevail that significant improvement of corrosion resistance can be achieved after laser treatment process
- …
