NUST Institutions Library Catalogue Search for 'kw,wrdl: (su-br:"MS Mechanical Engineering ")'

Water Brake Engine Dynamometr Control And Software Development

By Nayyer Nayyab Malik. Islamabad SMME NUST 2013 . Unspecified 30cm..

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Numerical Investigation of Effect of Breathing on Static Aerodynamic Characteristics of a Long Blunt-Nosed Body at Supersonic Speed /

By Naveed Akram. Islamabad : SMME - NUST, 2018 . ill, 38 p. ; , Hardcover.

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Fluid mechanics : fundamentals and applications /

By Çengel, Yunus A.,. . xxi, 1024 pages ; , Includes index. 26 cm. 9781259696534 | 1259696537

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New Approaches to Building Pathology and Durability /

. 1 online resource (VIII, 207 pages) 9789811006487

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Steel Fiber Reinforced Concrete : Behavior, Modelling and Design /

By Singh, Harvinder.. . 1 online resource (XI, 172 pages 56 illustrations) 9789811025075

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Seismic Assessment of Corrosion Resistant High Strength Low Alloy Steel (ASTM A588) Braced Frame using SAP2000 and MATLAB/Simulink /

By Saeed ,Ubedullah . Islamabad : SMME - NUST, 2014 . 89 p. ; 30cm..

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Experimental Analysis of Heat Flux Variation in a Brick Using Eutectic Phase Change Materials /

By ALI TAJ, SAMAD . . 48p. ; 30cm..

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Numerical Investigation of Vortex Induced Vibration of Rotating Circular Cylinder in Stream Wise Direction Subject to Oscillatory Flow /

By Kashif, Muhammad. . 71p. ; 30cm..

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Age-Specific Study of Airflow Distribution, Aerosol Transport and Deposition in an Unhealthy Human Lung using CFD-DPM Approach /

By Riaz, Hafiz Hamza . . 58p. 30cm.

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Preparation and Characterization of Pure Pla Filament and Pbat-Reinforced Pla Filament For Fdm 3d Printing /

By Naeem Ul Hassan. . 77p. , This study focuses on preparing pure polylactic acid (PLA) and polybutylene adipate –coterephthalate (PBAT)-reinforced PLA filaments. PLA and PBAT are biodegradable aliphatic polyesters and have recently received considerable attentions. Due to its brittle nature, PLA has limited application in various fields. To overcome this challenge, numerous efforts have been made to incorporate various additives to enhance its performance. In this work, pure PLA filament and PBAT-reinforced PLA filament with diameter 1.75 ± 0.02 mm were prepared in the lab. Their thermal and mechanical properties were analyzed and compared with the commercial PLA filament bought from the market. Following the previous research works and suggestions of incorporating no more than 10 wt.% PBAT, we have mixed 8 wt.% PBAT into the PLA mixture. We then proceeded to extrude pure PLA and PBAT-reinforced PLA filaments at a temperature range of 170 oC to 180 oC, utilizing single screw extruder. Next, we printed tensile and flexural specimens using an FDM 3D printer, in accordance with Taguchi L9 OA. Due to PBAT’s high ductility, 92-8 wt.% PLA-PBAT filament demonstrated a significant increase in elongation at break, reaching up to 12%. Likewise, the PLA-PBAT filament displayed tensile and flexural strengths of up to 48.34 MPa and 107.295 MPa respectively. These values are comparable to the tensile and flexural strengths of pure PLA, which is a great indication that the addition of 8 wt.% PBAT did not cause any unacceptable reduction in the tensile and flexural strengths. Additionally, it was found through DSC analysis that PLA-PBAT filament exhibited a higher degree of crystallinity (Xc) of up to 38.7%, which is significantly higher than that of pure extruded PLA. Furthermore, the TGA curve indicated that thermal stability of PLA-PBAT filament was improved by adding 8 wt.% PBAT. Moreover, digital microscopy results revealed that PLA-PBAT filament had a ductile fracture after necking, whereas pure PLA had a brittle fracture. Lastly, statistical analysis showed that both material type and layer thickness had significant impact on the results. The addition of this new PLA-PBAT filament provides an additional alternative to the current FDM filaments, and it will aid in reducing the constraints of the materials when it comes to additive manufacturing (AM) progress. 30cm.

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Analysis of Adhesive Joints using Digital Image Correlation (DIC) /

By Farooq, Muhammad Kashif . . 83p. , In this study, the effect of cork particles on the failure behavior of SLJs was investigated experimentally through tensile testing and non-contact digital image correlation (DIC) methods. Cork particles within size range of 125-250 μm were added at 0, 0.25, 0.50, 0.75 and 1.0% wt. in a brittle epoxy. SLJs with and without cork particles were tested under a displacement control condition of 1.3 mm/min and digital images were captured during the deformation in order to analyze the fracture process. VIC 2D 7 software was used to determine the peel and shear strain distributions in the overlapped area of bonded joints. Tensile test and DIC results reveal that cork particles enhance the strength and ductility of adhesive joints. However, the effect of cork particles on ductility is more significant than strength of joint. The visual inspection of the captured images shows cork particles act as crack stopper and slow down the crack propagation along the bondline. 30cm.

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Design of control system and fabrication of special compartment in Static Refrigerators /

By Arshad, Muhammad Bilal . . 54p. , Refrigerators being used for domestic purposes are of three types, namely static, brewed, and no-frost. The aim of this project was to introduce a new compartment in static refrigerators to enhance the quality and freshness of food present in this compartment. It was achieved by having control over temperature depending on the needs of the user and needs for the type of food inside the compartment. There can be two methods to fabricate this special compartment. One is by using parallel evaporators and other is by using fan and airduct. The parallel evaporator method is expensive but highly efficient, while air duct is less expensive and does not compromise enough efficiency, in term of energy consumption and cooling. The airduct was implanted in the refrigerator and results were taken. The result shows the total time to reach the target temperature, and time to drop per half degree of temperature. The target was to set the temperature at any value between 5 to -5 oC. In this project, the minimum temperature achieved was -1 oC, as the average temperature of evaporator goes to -12 oC, rather than the - 18 oC for most of the domestic refrigerators. 30cm.

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Effect of Hygrothermal Aging on Strength Performance of Cork Powder Reinforced Adhesive /

By Sohail, Zulekha . . 100p. , Adhesives play a crucial role across various industries and applications due to their ability to bond materials together. They are used in numerous ways, ranging from everyday household applications to industrial and specialized fields. Strength is the most critical factor to analyze before using the adhesive. Various techniques have already been developed and many are being developed to predict and improve the strength of adhesive. The addition of cork powder to the structural adhesives could improve the strength of adhesive joints through mechanical interlocking between the cork cells and the molecules of adhesive. However, even with the nanofiller reinforcement, the strength of adhesive joints is significantly affected by environmental parameters like temperature and humidity. The present study investigated the effect of hydrothermal aging on the strength characteristics of cork powder-reinforced adhesive samples. Reinforced adhesive samples were investigated under two different humidity levels of 80% and 100% RH. The cork powder will be added in concentration of 0.25wt.%, 0.5wt.%, 0.75wt.% and 1wt.% to study the reinforcing effects. The result shows that the saturated mass increased with increased in relative humidity that is approximately 0.4% and 0.9% for 80% and 100% RH respectively. The findings show that the ultimate tensile strength is reduced by the addition of cork powder as well as enhancing humidity. Furthermore, the addition of cork powder makes the sample more brittle, so failure strain and tensile toughness undergo decrement. The above finding indicated that hot-wet environment has a negative influence on strength performance of cork powder reinforced adhesive. In future the same study can be performed to know the strength of SLJ and DLJ to know its effect on joints. 30cm.

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Data Acquisition & Experimental Analysis Of Power Harvesting From Suspension System /

By Hassan, Ahmad Sabur . . 66p. , Energy crisis and environmental problems such as oil shortage and atmospheric pollution have brought challenges for new development of an energy saving, efficient and environment friendly power transmission system in vehicles. This research is focused on how to use the vibrational energy of the suspension system to generate power that would otherwise go as waste. It is demonstrated that the potential energy of driving vibration is sufficient to be utilized as a sustainable energy. The vibrations experienced by the shock absorber of the vehicle when passed through some irregularities on the road are converted into useful energy by using a regenerative linear or rotary mechanism. As shock absorber effect formed, spring is compressed, and linear movement of rack is converted in rotary motion due to pinion moves as the rack is meshed with pinion. And the pinion is mounted on the shaft of the generator which then produce the power. It is then used to calculate the practical power generated from the regenerative shock absorber by taking the real vibrations amplitude data from the road. The vibrations amplitude data is acquired from the road by driving motorcycle on different road conditions with the setup installed in it to calculate and store the vibrations amplitude data. Later, the same data is applied to the testing rig by using pneumatic and Arduino to find out the voltage generated. The power that is practically generated by testing the mechanism on the rig is around 9.5 watts. The harvestable power from the suspension depends on the vehicle speed, road roughness and stiffness of the tire. This regenerated energy is used to charge the battery. 30cm.

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Study the effect of shallow cryogenic treatment on mechanical and microstructural properties of 30CrMnSiA steel heat treated in vacuum furnace and Box Type conventional air furnace /

By Aslam, Muhammad Danyal . . 50p. , Heat treatment plays a major role in improving the material properties. With the addition of cryogenic treatment these properties can be further improved. In this paper heat treatment is carried out on low carbon low alloy structural steel in two different types of furnaces conventional box type air furnace and vacuum furnace along with shallow cryogenic treatment with the purpose to investigate the outcome of shallow cryogenic treatment on the material properties and to find out which type of furnace is more suitable with shallow cryogenic treatment. For this purpose, structural steel 30CrMnSiA was selected, and heat treatment was carried out in conventional box type air furnace (900°C × 40mins) and vacuum furnaces (900°C × 70mins), shallow cryogenic treatment (-75°C × 125mins) was carried out after the quenching and before tempering. For the physical properties of the material, hardness (HRC) was investigated using Brinell hardness tester HBD-62-5AP. Tensile samples were prepared as per ASTM E8/E8M and investigated using 100kN WAW-100B Electro-Hydraulic Servo Computer Control Universal Testing Machine. Impact toughness was measured by using electronic pendulum impact testing machine CBD-300 and specimens were prepared using ASTM standard E23-12c. Microstructural analysis for grain structure was carried out using Olympus DSX1000 optical microscope. 30cm.

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Assessment of Stress Biomarkers in the Saliva of Smokers and Nonsmokers via UV Photospectrometry and POMS /

By Fahim, Maria . . 99p. , Smoking is one of the major health catastrophes. Smoking is believed to be the major cause of chronic diseases like Cardiovascular complications, stroke, pregnancy issues, respiratory failure, etc. There are three important transdiagnostic emotional factors that make the population vulnerable to initiation of smoking i.e. anhedonia anxiety sensitivity, distress tolerance. Research studies for the past five decades have proven the adverse effect of stress on brain physiology and functioning. The human body responds to trauma (physical or non-physical stress) in a definite manner. This response of the body can be qualitatively and quantitatively monitored through several chemicals in the bloodstream, saliva, or urine; responding to the stress, called stress biomarkers i.e. Brain-derived neurotrophic factor, cortisol, cytokines etc. Saliva delivers an efficient specimen for various diagnostic procedures due to the presence of different biological products and secondary metabolites of xenobiotics and helps in determining the disease progressions as well as therapy outcomes depending on the variations in the markers/triggers. The nature of mindset and mood states are evaluated by a scales designed to rate the behavior of an individual towards the environmental stimuli that may be physical or psychological in nature. This psychological rating scale is known as the profile of mood state (POMS). This scale was initially originated by McNair, Droppleman, and Lorr in 1971. This scale is presented in the form a questionnaire including different questions regarding the mode and feelings of a subject.This research work aims to further elucidate the utilization of UV Photospectrometry for quantitatively assessing POMS and its relation to the stress biomarker. The samples were collected form the vicinity of the university campus H-12 Islamabad. The samples were processed and stored at the biomedical laboratory of School of Mechanical and Manufacturing Engineering (SMME), NUST. A total of twenty-four (24) male subjects were analyzed. A total of two groups were considered. Group 1 included the non-smoking participants, while group 2 included smoking participants. Simple spitting technique was used for the collection of unstimulated saliva. About 4 ml unstimulated saliva was collected in the sterile falcon tube. Saliva was temporarily stored in cool boxes at 4°C and immediately II shifted to the facility. Centrifugation of the salivary sample was done at 4°C for 5 minutes and 10,000 rpm. Saliva sample was frozen at -80°C until sample collection span was completed. The mood state of the participants was also evaluated using the profile of mood state technique used initially by McNair, Lorr, and Droppleman in 1971. The total mood disturbance (TMD) score was calculated that ranges from -32 to 200. The questionnaire was accessed from ―Mackenzie, B. (2001) Profile of Mood States (POMS) [WWW] Available from: https://www.brianmac.co.uk/poms.htm [Accessed 26/6/2022]‖. Simulated neural networking (SNN) was applied to the collected data from smokers and non-smokers for accuracy scoring. The required statistical analysis was performed and the data was statistically analyzed through a software ―GraphPad Prism 8.0‖ and the respective graphs were plotted. UV spectrophotometry studies provided peak plasma concentration peaks at the lower UV range of 190 to 210 nm, but with no significant difference, representing the presence of biological stress markers. The profile of mood state evaluation studies concluded that the smoking participants were presented with a significantly higher level of individual mood profile scores i.e. anger (****, P<0.0001), confusion (**, P<0.0014), fatigue (*, P<0.0354), tension (*, P<0.0422) and stress as compared to nonsmoking participants. The vigorous score was significantly high in the nonsmoking individuals (****, P<0.0001). Similarly, total mood disturbance score was also significantly high in the smoking participants. The application of artificial neural networking through artificial machine learning scored the accuracy of the results 84% which is a reliable outcome. The current research work concludes that different stress stimuli including physiological stress and psychological stress tends to initiate/increase the smoking behavior among the community. Likewise, it is also concluded that smoking initiation may not be always triggered in response to stress. Numerous factors i.e. lack of education, negative inspiration, or behavior to impress are also involved. Furthermore, the adaptation of smoking behavior as a result of stressful stimuli is not a valid approach to reduce the noxious/stressful stimuli. The stress may further be exaggerated by smoking. 30cm.

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Experimental Study of Lings Airways /

By Sardar, Hassan . . 55p. , Breathing is phenomenon essential for every mammal on Earth. Key role of respiratory system is transmission of vital gases between air and blood. Conventionally some macroscale techniques for flow visualization in trachea-bronchial region was achieved by using 3D printing of idealized/realistic airways model. Due to limitations in fabrication and CT image resolution, limited amount of experimental study is done on bronchial region. We fabricated simplified model of terminal bronchi airways by using polydimethylsiloxane. Micro-fluidic channel is fabrication by using the 3D printed molds via SLA printer (FormLabs 3+ with layer thickness of 50 μm). The mold is then used to fabricate transparent channel of PDMS which is good for visualization of flow. It is first of its kind of fabrication of terminal bronchial airways by using microfluidic chip fabrication method. Moreover, the chips fabricated using the PDMS have some paybacks like we can easily visualize flow passing through the airways. We use syringe pumps for flow of three breathing conditions sleep, normal and exercise. We demonstrated airways focusing using microscope and visualized fluid flow by using particle image velocimetry method. The statistics evidence good agreement with our experimental results and simulation results from the literature. The results shows that turbulence kinetics energy decreases by using pressurized meter dose inhaler. 30cm.

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Evaluation of different metal cutting models during machining of Inconel-718 /

By Hamza, M Ghazi . . 42p. , Inconel-718 is a nickel-based aerospace alloy that has large domain of applications in the aerospace industry and also in ground-based turbines. Machining of Inconel-718 is a very difficult process as it is able to retain its strength even at high temperatures resulting in a lot of tool wear and making it difficult to machine, thus making it a topic of interest among researchers. In order to study the orthogonal machining process of this material, development of a FEM model, in Abaqus software, which can simulate the process with good accuracy is extremely important. To simulate the plastic deformation and damage of Inconel-718, during the machining process, different material modelling techniques are available in the literature. Among these material models, Johnson Cook Plasticity model is widely accepted as being more accurate. When modelling the machining process using FEM, the Johnson Cook Plasticity model is utilized to forecast the plastic deformation and behaviour of a material. However, there are different values of parameters, involved in the JC model equation, available in the literature which have been derived experimentally. Using these different values of parameters in the simulation process of machining brings a variation in the output values. Thus, the need to evaluate these different models arises. This research will focus on identifying which model proves to be more accurate in predicting the cutting forces during machining of Inconel-718. Results obtained from each model will be compared to the experimental results and a conclusion will be derived about which model is preferrable to be used in simulation this process in future. 30cm.

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WATER BRAKE ENGINE DYNAMOMETER INSTRUMENTATION AND SOFTWARE DEVELOPMENT

By Alam., Umair. . 83p.; , Hardcover 30cm..

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Numerical Investigation of Hexacopter Downwash Airflow Field at Various Flight Speeds and Heights for Agricultural Spraying Operation. /

By Yawar Abbas, Muhammad . . 64p. ; , Multirotor Unmanned Aerial Vehicles (UAVs) as agricultural spraying drones have now become an integral part of the modern agricultural system. They are being used for spraying on the crops to protect the plants from different types of pests. When spray is distributed on the crops, it flows away from the target because of the wind field being created around the UAV. The downwash effect produced by the UAV significantly influences the spray deposition on crops. The downwash airfield generated by the hexacopter brings droplets to the crops, increasing the droplets’ deposition on the crops. Lattice Boltzmann Method was applied using CFD package XFlow to study the downwash field created by the hexacopter. The primary focus of the research is the downwash airflow field generated by the hexacopter that affects the motion distribution of droplets released from the sprayer at different flight speeds and altitudes. Previous research is limited to downwash effects on a drone with a wheelbase of 1000 mm. In this study, the downwash effect on a hexacopter drone with a spraying capacity of 30L and a wheelbase of 1900 mm is studied. We compared the results of our larger-wheelbase UAV with existing benchmarks. The UAV showed enhanced performance, achieving coverage and penetrable areas approximately double those of the benchmark. Based upon the results, the optimum flight height and flight velocity for spraying operation are 3 m and 4 ms-1 respectively under the condition of coverage and penetrable area. 30cm..

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Design Optimization and Surface Modification of Biodegradable Magnesium Alloy AZ91 for Biomedical Implants Using Electrical Discharge Machining /

By Shafiq, Danyal . . 105p. , Magnesium alloy AZ91, known for its lightweight nature, biocompatibility, and controlled biodegradability, is a promising material for orthopedic implants. However, faster corrosion in a physiological environment remains a challenge. This work investigates Electrical Discharge Machining (EDM) with copper and brass electrodes in a kerosene dielectric to optimize the surface roughness, hardness, and corrosion resistance of AZ91. Electrochemical deposition of copper and brass coatings was also performed to modulate the degradation rate. Surface assessment through Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) indicated that optimizing EDM parameters greatly improved the surface quality, which was characterized by less roughness and higher hardness. Of the coatings, copper exhibited better corrosion resistance, which slowed down the degradation of AZ91 in simulated body fluid (SBF). Therefore, this combination of EDM with electrochemical deposition opens up the possibility of developing patient-specific implants with controlled degradation rates, which ensures mechanical support during healing and avoids follow-up surgeries. This work paves the way for next-generation bioresorbable implants, effectively providing a bespoke solution to orthopedic applications integrating precision machining and surface engineering techniques. 30cm.

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Investigation of Impact Properties of Wave Springs Designed for Additive Manufacturing /

By Ahmed, Faizan . . 119p. , Innovation continues to transform various fields, including the design of springs. Initially helical springs were used as compression springs for most of the applications. However, the design innovation has led to the introduction of a new type of compression spring which is the wave spring. At the same time the advancements in manufacturing technologies are reshaping the production methods. Traditional manufacturing methods are gradually being replaced with additive manufacturing. Because AM has the ability to fabricate complex geometries with high precision and minimal material waste. These advantages make AM a key driver of innovation in modern design and engineering. Wave springs possess better mechanical properties as compared to helical springs, as highlighted by previous studies. But previous studies are limited to only compression analysis of wave springs at slow speeds. The behavior of this newly developed spring is unknown for sudden high speed impact loadings. This research involves the experimental and computational analysis of six different geometries of wave spring under the high speed loading conditions of 17mm/sec. The six geometries of wave springs are fabricated using FDM technology. PLA material was considered for the fabrication due to its availability and compatibility with the FDM. The other 2 materials including spring steel, and TPU (Thermoplastic Polyurethane) were used in computational modelling only. The results mainly showed that the material properties had a greater influence over the geometric parameters. PLA due to its brittle nature resulted in formation of local stresses that minimized the performance parameters of all geometries of wave springs. Spring steel having high elasticity and compressive strength showed better impact properties unlike PLA. TPU although elastic but moderate compressive strength was not able to show impact properties like spring steel, but due to its elasticity, it was a better choice over PLA. Each of the 6 geometries had different configurations that resulted in different local stress formations and thus different energy absorption, stiffness, and load-bearing capacity. To apply the concept of wave spring to real-engineering world, multiple wave spring designs were integrated in the car suspension system and analyzed on MSC Adams (Automated Dynamic Analysis of Mechanical Systems) for their energy absorption, stiffness, and maximum load bearing capacity. This analysis further validated the initial results and provided a gateway to the innovation in the car suspension system design and analysis. 30cm.

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Impact localization on Composite Panel using Fiber-Bragg Gratings optical sensors /

By Arhaam Bin Touqeer, . . 70p. , The advancing use of composites in high stake environments, particularly aerospace industry demands strict monitoring of composite’s health over the entire period of life. Health of composite structures could easily be affected by internal damages like debonding or delamination that are invisible to naked eyes. These damages are normally caused by unexpected impact incidences mid-flight or during ground handling. If these damages are not identified timely, could lead to catastrophic failure. So, there is a need of a system that could timely identify and locate these damages in real-time. FiberBragg Grating sensors have gained confidence with their capability of measuring strains accurately along with their versatile and low-cost integration, particularly in composites. In this research work, FBG sensors have been used to identify and locate impact incidences on a composite laminate. Capability of FBG sensors of measuring strain wave initiated by impact incidence is being investigated. In order to extract quantitative information from strain response for impact localization, novel concepts like Empirical Mode Decomposition (EMD) and Hilbert Huan Spectrum have been used. Lastly, normalized values from spectrum are utilized and Artificial Neural Network has been applied to train the system to differentiate between different damage states. On the bases of predictions made by optimized ANN, comments on FBG sensors reliability have been presented and prospects for future research work discussed. 30cm.

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Microplastic Behavior in Idealistic Exhalation Dynamics: Exploring Shape, Density, and Diameter Effects Using CFD /

By Siddiqui, Hadia Alam . . 60p. , Microplastics are now ubiquitous contaminants in the atmosphere which have raised substantial public health issues. While extensive research has focused on particle deposition during inhalation, the exhalation phase, a critical component of the complete respiratory cycle, remains comparatively less explored. The study aims at addressing this research gap by conducting a comprehensive computational investigation into the deposition dynamics of microplastic particles during exhalation within an idealized human tracheobronchial airway model from generations G3–G6. A three-dimensional airway geometry was constructed via Weibel's morphometric data, adjusted for a 50-year-old adult. Computational Fluid Dynamics (CFD) simulations are performed using the Reynolds-Averaged Navier-Stokes (RANS) approach with the (SST) 𝑘-𝜔 turbulence model. The Discrete Phase Model (DPM) was employed to track trajectories of spherical microplastic particles 2-22 µm under four exhalation flow rates 125, 300, 500, and 1000 ml/s, representing varying breathing intensities from resting to heavy exercise. The results demonstrate an inverse relationship between exhalation flow rate and overall deposition efficiency (DE). Lower flow rates resulted in the highest DE, as particles had greater residence time for gravitational sedimentation and were less influenced by turbulent dispersion. In contrast, higher flow rates generated significant turbulent kinetic energy, which enhanced particle mixing and reduced net deposition. Furthermore, deposition was strongly governed by inertial impaction, as evidenced by a positive correlation with the Stokes number. Spatial analysis revealed that while high flow rates created intense deposition hotspots at major bifurcations, the cumulative particle deposition isXIV significantly lower than at gentler flow rates, where deposition is more widespread. This study concludes that gentle exhalation poses a greater risk for microplastic retention in the lower bronchial airways. The findings challenge the assumption that higher airflow invariably leads to increased deposition and provide crucial insights into the mechanisms of particle exposure during the exhalation phase. 30cm.

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Design and Development of Toroidal Propeller for Drone Applications /

By Ali, Aarib Irfan . . 182p. , The demand for low-noise and ecient propulsion systems for unmanned aerial vehicles has driven research into unconventional propeller designs. One such promising conguration is the toroidal propeller, which has gained attention for its potential to reduce noise emissions while maintaining or improving aerodynamic performance. The research follows a methodology that begins with an extensive literature review and operating point selection to dene the design requirements and constraints. A validated computational setup was developed using unsteady RANS-based CFD simulations. Several toroidal propeller concepts were initially generated, out of which a baseline model was selected for further study. The baseline design was optimized using a Design of Experiments response surface methodology and obtain an optimized propeller with maximum thrust and reduced noise. Sensitivity analysis was carried out to assess the inuence of individual parameters on thrust, torque, and noise. The optimized design showed signicant improvements in thrust with considerable reduction in noise as compared to initial concepts. Aeroacoustic analysis was also performed to evaluate the noise characteristics of the toroidal conguration. Using broadband noise models, the toroidal propeller demonstrated promising reductions in tonal noise components, making it suitable for operations in noise-sensitive environments. To validate the computational ndings, experimentation validation was also performed. The optimized toroidal propeller was evaluated using ve dierent materials: ABS, PLA, PETG, CF PETG, and an Engineering Resin via Finite Element Analysis. Suitable manufacturing methods were employed and a custom test bench conguration XXII was built to test the propeller thrust and noise. The propeller was tested under controlled conditions for thrust and noise. The experimental results matched closely with the computational results and veried the validity of toroidal propelelr as viable replacement of traditional propellers for UAVs, oering advantages in both thrust and acoustic performance. The toroidal propeller showed higher value of thrust over complete range of RPM and and delivering upto 35% more thrust than traditional propeller at 15,000RPM. In addition, it also had a lower acoustic signature and was 11% quieter than the traditional propeller. The successful integration of computational design, optimization, and experimental validation demonstrates the practical potential of this novel propeller architecture. Furthermore, the research lays a foundation for future work involving transient LES acoustic modeling, in-ight testing, and applicationspecic customization of toroidal designs. 30cm.

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Customization of 3D-Printed Knee Implants: Design Optimization and Lattice Structure Integration fo Enhanced Performance /

By Ahmad, Fatima Ajaz . . 93p. , Total Knee Replacement (TKR) surgeries are becoming increasingly common globally as an effective measure to counter knee arthritis. Total knee replacement implants are very advantageous in a sense that they offer 99% success rate to patients. This thesis presents the design, simulation and additive manufacturing of a patient specific, Functionally Graded Lattice Structure (FGLS) knee implant in Ti 6Al-4V alloy with specific reference to the healthcare situation in Pakistan. This was to explore the local manufacturing facilities of Pakistan as all knee implants are imported from abroad. The strategy involved a high degree of workflow consisting of Computer-Aided Design (CAD), finite element analysis (FEA), and topology optimization using nTopology to create Gyroid-based lattice work. The structures were to resemble the trabecular bone structure to ensure that stiffness discrepancies were minimized. This helped counter only one drawback of solid knee implants, stress shielding. The simulations of the physiological loading conditions (static and cyclic) demonstrated a Von Mises peak of 620.45 Mpa and safety factor of 12.66 on the average and unlimited predicted life of fatigue of over 10^7 cycles. The use of FGLS was effective in making the weight of 490 g to 292, leading to a 40 percent weight reduction, with no structural integrity lost. Selective Laser Melding (SLM) was used to fabricate the implant and the heat treatment allowed stress relieving of the additively manufactured implant. Compressive testing was also mechanically vindicated to be on an of average 95.02 kN with little variation and Micro-CT scanning confirmed high dimensional fidelity and showed internal lattice geometries without defects. According to this research, SLM produced FGLS implants usage has proven to be an option to traditional prosthetics, which is mechanically stable, biologically desirable, and cost-effective, and has a bright future of being a locally manufactured orthopedics product. 30cm.

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Experimental Research on solar still technology, a promising solution for water purification in developing countries /

By Malik, Nawaf Mehmood . . 86p. , Water scarcity is a major problem, which the world is facing at the present moment. Most of the earth’s water is saline, comprising about 97 %. Solar still is a very economical and easy method for water desalination. This experimental research was conducted to enhance the output of square pyramid type solar still incorporating PCM (paraffin wax) and Fresnel lenses concentrating sunlight on bricks placed in basin area. Effect of hot water circulation in PCM was also observed on solar still distillate output enhancement. Experiments were conducted at different water depth levels (i.e., 1, 2, 3 and 4 cm) in Islamabad, Pakistan. Nocturnal output was observed to increase by using Fresnel lenses. Solar still output was observed to increase from 1 cm to 3cm in nocturnal hours and then started to decrease. When Fresnel lens was used, maximum distillate output in autumn and spring season was 0.9 L and 1.68 L at 1 cm water depth. Maximum distillate in simple experimental cases (without Fresnel lens utilization) was also at 1cm water depth. In autumn season it was 0.85 L and in spring 1.55 L. Circulation of hot water in PCM chamber increased both daytime and nocturnal output of solar still significantly 30cm.

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Investigation and Optimization of Critical Response Variables in Wire Electrical Discharge Machining of SmCo₅ Magnetic Material /

By Mehmood, Adil . . 99p. , The magnetic alloys of samarium-cobalt SmCo₅ have been used in high-performance engineering as a result of their outstanding thermal stability and magnetic strength, but they are hard and brittle, which is a major challenge when trying to machine these using traditional machining methods. Wire Electrical Discharge Machining (WEDM) provides a practical approach to find a solution to shape such hard-to-machine materials, but a full picture of parameters and their response for SmCo₅ has not been established. The present study examines the effect of the essential parameters of the WEDM processes on the critical performance parameters, such as the kerf width, the surface roughness and the material removal rate (MRR), for machining of SmCo₅. An experimental design using Taguchi L18 array was used whereby the impacts of electrical, mechanical, and materialrelated factors were evaluated in a systematic manner and experimental trials were conducted. Analysis of Variance (ANOVA) achieved statistical analysis results that pulse on time is the primary determinant of kerf width via control of discharge energy, and pulse off time is the ultimate determinant of surface roughness safe through control of discharge stability and discharge cooling behavior. It was discovered that material removal was highly influenced by servo voltage because of the erosion behavior of the brittle magnetic alloy was not uniform. Multi-response optimization was conducted with the aid of the Weighted Sum Normalization, the Multi-Response Signal-to-Noise Ratio and the Grey Relational Analysis to handle the multiple machining objectives of conflicting nature. Of these, the Grey Relational Analysis had the best fit to the experimental results hence indicating better ability in the modeling of overall machining performance. 30cm.

Place Hold on Investigation and Optimization of Critical Response Variables in Wire Electrical Discharge Machining of SmCo₅ Magnetic Material /