Dinesh Kumar Rao

Dehumidification systems based on liquid desiccant have the potential to lower the latent cooling load of traditional vapour-compression airconditioning, especially in humid climates. This paper presents an experimental research on a liquid desiccant dehumidification system using calcium chloride that was run under controlled winter conditions. The effects of inlet air velocity and regeneration temperature on the outlet air relative humidity are evaluated. The results indicate that lower air velocities improve moisture removal because of increased air–desiccant contact time. The regeneration at about 58 C gave a relatively stable regeneration behaviour with a small range of outlet air relative humidity under the conditions of the experiment. The work gives experimentally determined operating trends applicable to real-world humidity-control applications and low-grade heat regeneration, and observes that the results are not to establish universal performance standards but to assist in optimising systems.

Composite manufacturing is a revolutionary innovation in materials science that integrates dissimilar materials to formulate new material with enhanced mechanical, thermal, and chemical characteristics. This chapter overview encompasses the types of composites, manufacturing methods, properties of composites, their applications, and the limitations and prospects of sustainable development. They possess a high ultimate tensile strength-to-density ratio or specific strength and are lightweight; thus, they are applied in the aerospace and automotive industries. For example, carbon-fiber-reinforced polymers or CFRPs are used much in aeroplanes to increase the use of small fuel and minimize emissions. Still, constraints including high production costs, difficult manufacturing processes, and restricted possibilities of recycling are drawbacks to their widespread use. Environmental impacts as a factor are important in the fabrication of composites. Investigations are being made on using renewable resources in the formation of biodegradable composites to increase recyclability. Now, in Industry 4.0 give the new advances techniques for the recycle the material and allow this material to used in next manufacturing of composite. Prospects include innovations in the area of nanotechnology and the incorporation of smart materials to improve the characteristics and performance of composite goods. In summary, the ongoing advancement of composite manufacturing, particularly with a focus on sustainability, offers significant potential for innovative growth within the industry. This development also holds promise for greatly reducing the carbon footprint in the broader context of sustainable manufacturing practices worldwide. Composite materials are widely utilized in various sectors, including aerospace, automotive, and defense, among others.

Electric vehicles and hybrid electric vehicles are changing the face of the automobile industry by catalyzing it to develop new materials to enable better performance and sustainability. In most of these transformations, polymers and composites are crucial in improving energy efficiency and extending driving range through their lightweight properties. The weight-reduction potential is high through substitution from traditional materials into advanced polymers, resulting in better acceleration, braking, and battery life. Beyond being lightweight, polymers play a key role in effective thermal management to guarantee optimal battery performance through their behavior as both good insulators and conductors. Their exemplary electrical insulation helps ensure safety in high-voltage systems. Increased usages of composite carbon fiber-reinforced polymers (CFRPs) in structural components allow higher strength-to-weight ratios, enabling crashworthiness and design flexibility. The major drawbacks of composites’ widespread usage include manufacturing complexities and recyclability problems. Material science and production techniques will be crucial in response to these issues in the future of EVs and HEVs. Ongoing research now indicates that polymers and composites are going to impact the automotive sector, driving improvements toward better efficiency, greater safety, and greater sustainability.

The present study focuses on the fabrication and analysis of thermal and dynamic mechanical properties of epoxy bio-composites reinforced with 15 wt.% sisal fibers and varying carbon nanotube (CNT) content (0–2.0 wt.%). As per the results, incorporation of 1.0 wt.% CNT significantly enhances thermal and mechanical properties of the composite. Compared to the baseline composite without CNTs, thermal degradation onset has been improved by approximately 13%, while crystallinity and thermal resilience also increased. The storage modulus and loss modulus rose by approximately 79% and 197% respectively, indicating greater stiffness and energy absorption capacity. The damping factor (tan δ) decreased by over 56%, implying enhanced load-bearing capability with reduced energy dissipation. These improvements are attributed to better interfacial bonding and uniform CNT dispersion at 1.0 wt.%. The SEM analysis of epoxy bio-composites also revealed that the optimal dispersion and strong interfacial bonding are achieved at 1.0 wt.% CNT. Overall, the findings demonstrate that optimal thermal stability and viscoelastic properties occur at low CNT content in natural fiber composites, making them suitable for advanced structural applications in automotive, aerospace, and packaging sectors.

The present study investigated the thermal and dynamic mechanical properties of epoxy polymer bio-composites reinforced with 15 wt.% sisal fiber and varying concentrations (0, 0.5, 1.0, 1.5, and 2.0 wt.%) of carbon nanotube (CNT) additives. Thermogravimetric Analysis (TGA) revealed that the composite with 1.0 wt.% CNT exhibited the highest thermal stability, with minimal weight loss across a temperature range of 30°C – 790°C. Differential Scanning Calorimetry (DSC) results indicated enhanced crystallinity and thermal resilience in the 1.0 wt.% CNT formulation. Dy-namic Mechanical Analysis (DMA) indicated that the proposed composite has the highest storage modulus of 3859.28 MPa, loss modulus of 539.44 MPa, and a glass tran-sition temperature of 89.26°C. It also has the lowest damping factor (tan δ = 0.25), de-noting superior stiffness and reduced energy dissipation. The reported results highlight the optimal reinforcement effect of 1.0 wt.% CNT, improving thermal stability, mechanical performance, and interfacial bonding in sisal fiber-reinforced epoxy composites for advanced industrial applications.

The present study investigates the synthesis and characterization of a zirconium oxide (ZrO₂)-based metal composite doped with cerium (Ce) and yttrium (Y), using chromium (Cr) and nickel (Ni) as base metals. These constituents were selected for their superior mechanical properties and compatibility with the ceramic phase. High-purity powders were homogenized via high-energy ball milling, followed by cold pressing and sintering in a controlled atmosphere of hydrogen. The sintering process was conducted at temperatures ranging from 850 °C to 1350 °C to examine the evolution of microstructure, grain growth, and densification. Scanning electron microscopy (SEM) revealed a homogeneous distribution of phases, with distinct microstructural features attributed to each element at different sintering temperatures. The experimental results revealed that the composite’s density was increased by 30% and porosity was reduced by 61% at a sintering temperature of 1350 °C. The hardness and flexural strength of composite were found to be 23% and 60% higher at 1350 °C, respectively, compared to that at 850 °C, suggesting enhanced mechanical properties due to cerium and yttrium reinforcement within matrix and efficient doping and phase transformation. Overall, incorporation of cerium and yttrium significantly improved mechanical behavior and phase stability of ZrO₂–Cr–Ni composite, highlighting its potential for advanced engineering applications.

This study investigates the synthesis and characterization of zirconium oxide (ZrO₂)-based metal-composites doped with cerium (Ce) and yttrium (Y), using chromium (Cr) and nickel (Ni) as base metals. These constituents were selected for their superior mechanical properties and compatibility with the ceramic phase. High-purity powders were homogenized via high-energy ball milling, followed by cold isostatic pressing (CIP) and sintering in a controlled atmosphere. The sintering process was conducted at various temperatures (850°C to 1350°C) to examine densification, grain growth, and microstructure evolution. Scanning Electron Microscopy (SEM) revealed a homogeneous distribution of phases, with distinct microstructural features attributed to each element at different sintering temperatures. Density measurements using the water immersion method and theoretical calculations demonstrated increased density and reduced porosity with higher sintering temperatures. Vickers hardness testing indicated that hardness improved with increased sintering temperature, peaking around 1150°C due to cerium and yttrium reinforcement within the matrix. Flexural strength tests showed the highest value at 1350°C, with a significant drop in porosity, suggesting enhanced mechanical properties due to efficient doping and phase transformations. Overall, the incorporation of cerium and yttrium significantly improved the mechanical behavior and phase stability of the ZrO₂-Cr-Ni composites, highlighting their potential for advanced engineering applications.

The use of petroleum based non-degradable polymers and the effect of petroleum products directly impacting lives. Therefore, eco-friendly biodegradable composites are attracting more and more researchers. Biodegradable composites are prepared by using hand layup process using Kondagogu gum(KGG) resin with oil palm mesocarp fiber(OPMF) as reinforcement. Mechanical properties such as tensile, flexural, impact and Thermogravimetric (TG/DTA) of the composites are evaluated. The effect of fiber loading on the mechanical and thermal properties of the composite is also studied.