http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/134 2026-04-03T18:02:53Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/11809 Understanding the Force Deflection Behavior of NiTi Archwire at Distinct Bending Configuration: A Narrative Review in Vitro Studies Munir, A; Zulfiqar, S; Joy Mathavan, J.; Sohail, A This study aims to assess the optimal unloading force range for human comfort by considering NiTi archwires in different bending settings, based on previous research findings. All the relative data has been collected from different databases such as PubMed, Google Scholar, Scopus, Web of Science, and USM library. The publications from 2007 till February 2023 have been incorporated. Several parameters related to orthodontics, especially the usage of three brackets and three-point bending with respect to optimal tooth force were taken into consideration. These parameters, however, included various aspects like the shape memory effect, bending temperature, friction, and gingival/labial direction. ISO standards pertaining to the bending tests were also contemplated in this review. The study examined 74 articles related to orthodontic tooth movement, three brackets, and three-point bending. In fact, this review was done to analyze the force deflection behavior and related parameters to orthodontics. For this, among 74 selected research items, 15 studies gave information about the optimal tooth force, 8 focused on the optimal ranges, while 7 reports indicated the higher rates of tooth force. All these studies illustrated the considerable variation in methodology and clinical diversity in terms of applied forces. This article summarizes previous investigations on orthodontic tooth force, highlighting the ideal range of 0.2 to 1.5 N. It concludes that maximum force decreases with greater inter-bracket distance but increases with wire deflection and testing temperature. Proper force management is emphasized as crucial for preventing unwanted tooth movement and its biological consequences. 2024-01-01T00:00:00Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/11808 SELF-NAVIGATION INTERFACE SYSTEM IN COMPLEX BUILDINGS USING MICROCONTROLLER Raafeek, A.R.M; Kunaraj, A.; Joy Mathavan, J. Self-navigation technology proves to be among the most advanced methods for locating specific positions. However, it remains challenging to accurately determine desired locations within intricate building structures using self-navigation. This research introduces a cutting-edge Self-Navigation and Interface System designed to address the complexities of indoor navigation in diverse environments such as universities, banks, shopping centres, and restaurants. The system leverages microcontroller technology as its control system, featuring a bespoke app interface integrated with microcontroller and Bluetooth modules. The app, accessible via system-installed touchscreens or mobile phones, empowers users to effortlessly select specific location points, streamlining navi gation within intricate indoor spaces. A key highlight of the system is its utilization of LED lights; each assigned a unique color, to guide users along the optimal path leading to different destinations. This innovative approach provides clear visual cues enhancing user orientation. Moreover, when transitioning to different indoor locations, the system seamlessly incorporates a map display feature through the app, offering users a compre hensive view of their surroundings. The microcontroller-based control system ensures the synchronization of LED lights and map displays, offering users a user-friendly and effi cient means of navigating complex environments. Bluetooth modules facilitate real-time communication between the app and the system, ensuring timely updates and responsive interaction. This research contributes to the advancement of self-navigation systems, par ticularly in multi-story buildings where traditional navigation solutions may fall short. The seamless integration of microcontroller technology, LED lights, and Bluetooth mod ules establishes a robust platform for creating an intelligent and accessible self navigation experience. The proposed system not only streamlines navigation within di verse indoor environments but also enhances user interaction through an intuitive app in terface, thus addressing the evolving needs of modern navigational systems. 2024-01-01T00:00:00Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/11807 Process enhancement and performance evaluation of single‑shot drilling of CFRP/aluminum stacks: a review Joy Mathavan, J.; Hassan, Muhammad Hafiz Drilling is an essential process in the construction of aircraft panels made from composite/metal stack materials, and it has a considerable impact on the performance of the aircraft during flight and its overall lifespan. Among CFRP/Al/Ti, CFRP/ Ti, and CFRP/Al stacks, CFRP/Al panels are widely used in the aviation industry. This paper examines in detail the develop ments made in the drilling of stacks made of carbon fiber reinforced polymer (CFRP) and aluminum (Al), with the goal of determining how different machining parameters affect the quality of the holes. The primary requirements for aircraft com ponents are to attain a low level of hole surface roughness, minimize burr heights, reduce the diameter difference in stack-up, and minimize delamination. The subject matter encompasses a wide range of tool shapes, materials, drilling parameters, and innovative methods of cooling and coating, all with the goal of reducing hole damage and improving quality. In addition, the paper examines several forms of hole damage and presents modern methodologies for their quantification. This review study aims to develop a reliable standard for achieving accuracy, optimal productivity, and reducing harm in the drilling procedure of CFRP/Al stacks in aerospace applications. Future works on analysis of bond strength, hardness, and coefficient of friction of coated drill bits and application of nano fluid-based coolants may further enhance the drilling quality 2025-01-01T00:00:00Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/11806 Comprehensive review of drilling strategies for CFRP/Ti s tacks in aircraft manufacturing Joy Mathavan, J.; Hassan, M.H. Single-shot drilling of carbon fiber-reinforced polymer/titanium alloy stacks in aerospace applications poses unique challenges. The interaction between the cutting tool and the composite- metal contact often leads to poor hole quality and increased tool wear. The review extensively examines research achieve ments and developments in drilling CFRP/Ti stacks to compre hensively assess the impact of various machining settings on hole quality. Contributing factors such as stack-up machining thrust force, temperature, chip form and tool wear characteris tics are thoroughly investigated. Moreover, this article high lights manufacturing defects in metallic and composite panels during drilling operations, contributing to a higher rejection rate in the assembly process. Usually, the maximum delamin ation of 1mm, diameter deviation of ±30mm, burr height of 150mm, metal part’s surface roughness of 1.6mm and CFRP part’s surface roughness of 3.2mm are allowed in the aero space industry. Additionally, the research explores strategies to mitigate manufacturing defects, including measures to limit hole and tool damage. These tactics encompass tool structure, machining environment, machining parameters and machin ing technology. On the whole, this review study aims to fill the research gap regarding process enhancement and per formance evaluation of single-shot drilling of CFRP/Ti stacks in aerospace applications. 2025-01-01T00:00:00Z