Speaker

Assoc. Prof. Ir. Ts. Dr. Mohamad Hafiz Mamat

Universiti Teknologi MARA (UiTM)

Title: Fabrication of Resistive-Type Humidity Sensor Using Metal Oxide Nanostructures Synthesized via Chemical Solution Process 

In the past decade, humidity sensors have been widely studied and considered in the various applications including agriculture, food industries, climate monitoring, chemical storage, healthcare, and semiconductor industries. The studies have been focused to prepare humidity sensor with good humidity sensing performance and low cost, which required for large-scale volume and to fulfil the rigorous performance obligations of the emerging areas. In this research, resistive-type humidity sensors were fabricated using zinc oxide (ZnO), titanium dioxide (TiO2) and nickel oxide (NiO) nanostructures. These nanostructures were produced using solution immersion method. This method is cost-effective fabrication process, which could produce nanostructure films in large scale. The results obtained in this research show that metal oxide nanostructures in form of ZnO nanorod arrays, flower-like TiO2 nanorod arrays and NiO nanoball/nansoheet structures are good candidates for humidity sensing applications. These nanostructures produce high humidity sensing sensitivity and could provide potential humidity sensing applications in the emerging areas.

Assoc. Prof. Dr. Zaleha Mustafa

Universiti Teknikal Malaysia Melaka (UTeM)

Title: Exploring the Cyclic Behavior of Polylactic Acid (PLA) Composites for Enhanced Durability and Reliability

In recent years, the pursuit of sustainable materials has gained significant momentum, driven by the urgent need to address environmental challenges. Among these materials, Polylactic Acid, or PLA, stands as a leading biodegradable and renewable polymer. PLA, derived from renewable resources such as corn starch or sugarcane, has found various applications in single-use items, packaging, and biomedical products. However, its limited mechanical properties have often restricted its application in more demanding industries. The incorporation of reinforcing agents, such as natural fibers, glass fibers, or carbon nanotubes, has demonstrated remarkable success in improving the mechanical properties of PLA-based composites. These reinforcements contribute to increased tensile strength, flexural modulus, and impact resistance, enabling broader applications in industries like automotive, construction, and aerospace. By carefully selecting the type, length, and content of reinforcing materials, we can tailor PLA composites to meet specific performance requirements. Nevertheless, the behavior of these composites may differ significantly when subjected to static and cyclic loading conditions. Understanding how these composites perform under repeated stress cycles is vital for their application in various industries, including automotive, construction, and consumer goods. Fatigue behavior, the phenomenon of progressive damage under cyclic loading, is of paramount importance when designing materials for long-term performance. We will examine the fatigue characteristics of PLA composites using comparison of two different types of fibers un factoring stress amplitude and the number of cycles to failure. Additionally, we will discuss the underlying failure mechanisms, including matrix cracking, fiber-matrix debonding, and delamination, to comprehend how they influence the composite's endurance.

Dr. Wan Khairul Muzammil Bin Abd Rahim

Universiti Malaysia Sabah (UMS)

Title: Development of Low Wind Speed Vertical Axis Wind Turbine

Vertical Axis Wind Turbines (VAWTs) have gained increasing attention as a promising solution for harnessing wind energy in low wind speed conditions. Unlike their horizontal axis counterparts, VAWTs are known for operating efficiently in turbulent and low-speed wind regimes. This paper comprehensively reviews the state-of-the-art advancements in VAWT technology, focusing specifically on their performance and viability in low-wind speed environments. The challenges associated with conventional horizontal axis wind turbines at low wind speeds led to their limited efficiency and operational constraints. This inadequacy has spurred research and development efforts to explore alternative solutions, leading to the emergence of VAWTs as a feasible option to address these limitations. Research into the design and operational principles of VAWTs tailored for low wind speed conditions has spurred many unique designs over the years. Various aerodynamic designs, such as the conventional Darrieus and Savonius types, are examined for their merits and drawbacks. Moreover, a new concept of applying a Total Airfoil Structure (TAS) into the VAWT design has shown a tremendous advantage over the conventional design in VAWT rotors. The improvement in power output shows the great potential of VAWT technology in low wind speed regions, especially in tropical countries such as Malaysia. With their unique operational capabilities and continuous technological advancements, VAWTs offer a promising solution to expand renewable energy deployment and foster sustainable development in regions with previously untapped wind resources.

Ir. Dr. Chua Bih Lii

Universiti Malaysia Sabah (UMS)

Title: PROGRESS IN DIRECTED ENERGY DEPOSITION PROCESS FOR REMANUFACTURING

Remanufacturing mainly used to reconstruct worn components, or to restore degraded products to their original condition. This prolongs the lifetime and value of a product in a circular economy. Directed energy deposition (DED) process is one of the most technique that can be used to repair and remanufacturing metallic parts. During the DED process, the metallic feedstock in the form of powder or wire is delivered directly to the heat source and combined with the melt pool to form the repaired region. A typical remanufacturing using DED process involves pre-deposition machining, DED process and post-deposition machining. However, due to different grade of materials, material integrity such as cracks at interface is commonly found after the process. Several issues and challenges using the DED process for remanufacturing are presented and discussed. Recent strategies and progress to resolve the challenge are summarized, including the use of thermo-mechanical analysis, and selection of sequence and interpass time between deposition.