NUST Institutions Library Catalogue Search for 'an:"119569"'

Friction and Wear Performance Analysis of Grey Cast-Iron G3000 against 52100 Steel ball bearing With Bio-Lubricants and NanoAdditives under Reciprocating Motion /

By Iqbal, Chaudhry Kashif . . 85p. 30cm.

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Energy Harvesting by using Exhaust Gases of Heavy Vehicles /

By Munir, Muhammad Bader . . 86p. 30cm.

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Design & Development of a Concrete 3D Printer /

By Changez, Kashif . . 79p. , This research focuses on designing and developing a concrete 3D printer which uses the Fused Deposition Modeling (FDM) technology. The primary objective of this thesis is to introduce 3D Concrete Printing (3DCP) technology in Pakistan to address the housing challenges and providing cost-effective efficient construction solutions. This research aims to contribute to the construction industry by proposing a conceptual design, fabricating a 3D printer, investigating different concrete mixes, evaluating performance of the developed printer, and employing recycled and agro-based materials to the mixture to make it sustainable. This technology holds the potential to revolutionize the construction industry, reduce labor costs and injuries, and use raw materials efficiently which will positively impact the region’s economy. The study also explores the intricate relationship between different concrete additives and their influence on the mechanical strength of 3D printable concrete (3DPC). By emphasizing the importance of balancing printability, strength, and evaluating specific additives such as Fly Ash, Silica Fume, Rice Husk Ash, Crushed Recycled Concrete, and Crushed Recycled glass, this research provides valuable insights about the basis on which a material mixture must be designed for 3D printing (3DP). Also, by employing superplasticizer and viscosity modifying admixture, the research comprehensively analyzes the flow properties of fresh 3DPC and the strength performance of water-cured samples at day 7 and 28. The significance of early-stage strength development and sustainability considerations empowers this research to contributes to the existing discourse surrounding 3DCP technology, paving the way for an additive-enriched formulation that harmonizes printability, structural performance, and environmental responsibility. 30cm.

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Flight Stability of UAV-Manipulator System for Grasping Applications using Sliding Mode Control /

By Sial, Munadi Ahmad . . 122p. , An Aerial Manipulator is a coupled system which consists of a robotic arm attached to the body of a drone. A drone is itself a non-linear system which is linearly approximated to enable PID control. With the addition of a manipulator, the non-linearity is increased to a significant extent. The combined system has very complex dynamics due to the shifting of the center of mass from actuating the arm. This places a great demand on the flight control system in order to maintain stability. Another problem is the sudden change in system dynamics whenever an object is grasped. The benefit of such a complex system is that the drone will be able to physically interact with the environment that it is inspecting. The interaction can be in the form grasping, pushing, pulling and transport of objects. The purpose of this research is to design and control an aerial manipulator for the stable grasping of small objects. 30cm.

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Tribological Performance Analysis of Grey Cast-Iron against 52100 Steel Ball Bearing with Poly-alpha olefin Lubricant with Nano Additives under Reciprocating Motion /

By Nasir, Muhammad Anas. . 70p. , This study is based on nano-particle based lubricants and their role in enhancement of tribological performance of base oil. CuO, ZnO and MoS2 nanoparticles are added to PAO-10 in 1wt% concentration along with 2wt.% oleic acid as a dispersant, these three mixtures are then set up for testing with a tribo-pair of ASTM-52100 steel ball and SAEJ431 (G-3000) gray cast iron. The tests are carried out on a computer controlled reciprocating tribometer and all the lubricants are subjected to 10N, 20N and 30N loading conditions. Test duration is 7200 seconds, at 50 rpm and ambient temperature. Under these conditions and a sliding point contact the test rig is designed to test lubricant performance under boundary lubrication regime. To study the wear scar, a digital optical microscope was used and dimensions for each wear scar were recorded along with the surface roughness before and after the testing. The reciprocating tribometer tests were also conducted on SAE-40 and SAE-0W20 fully formulated oils to compare the results with nano-particle based lubricants. The results from the tribometer tests suggest that ZnO nanoparticles showed positive results by slightly improving CoF values and showed a significant reduction in wear volume. CuO nanoparticles showed improvement in CoF values for lower loading conditions but could not improve performance for higher loading conditions. The MoS2 nanoparticles were observed to be most effective in reducing the CoF and wear scar volume when added to PAO-10. The lowest CoF value was observed with PAO+MoS2 at 20N load, which is a 93% improvement as compared to PAO-10. The lowest value for wear scar volume was observed for PAO+MoS2 at 10N load which was 92% improvement as compared with PAO-10 only. This study further discusses the mechanism that physically changes the sliding conditions and play part in reducing the CoF and wear due to presence of nanoparticles and tries to relate them with the results of this study. 30cm.

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