Search

It is now widely accepted that various subsets of hybrid fiber composites reinforced with combined natural and synthetic fibers can significantly expand the applicability of composite-based materials in design and technology practice. The already existing unnatural circumstances on the planet put natural fibers far ahead of traditions in the field of materials thanks to their biodegradability characteristics, availability and over-term endurance and corrosion resistance. At the same time, composites are rapidly taking their place in many industries and sectors of the economy as metals in as much as it is economically and energetically justified. This study evaluates the mechanical properties of hybrid composites reinforced with glass, hemp, and sisal fibers. Using a hand lay-up method with epoxy resin, composite laminates were fabricated and tested for tensile, flexural, impact strengths and hardness test in accordance with ASTM standards. The experimental results revealed that glass-sisal fiber composites achieved the highest tensile strength of 69.1 MPa, while glass-hemp-sisal fiber composites exhibited superior flexural strength of 15.22 MPa and impact strength of 137.45 kJ/m2while best hardness value was 24.73 HV for glass-sisal fibre composite. These findings underscore the potential of glass-sisal-hemp fiber-reinforced epoxy composites as viable alternatives to traditional synthetic fiber-reinforced materials in automotive industry where there are no structural loadings i.e. automobile interiors; offering enhanced mechanical performance and sustainability.

ABSTRACTObjectives. Current research aims to identify factors that affect the occupational safety climate in university laboratories despite their perception as low-risk areas compared to industrial environments. Methods. A safety climate survey was conducted in science laboratories across various engineering universities in Pakistan. The survey questionnaire was administered to 406 personnel, and a quantitative method for analysis was selected to examine the socio-demographic variables. A 5-point Likert scale (1 =  strongly disagreeto 5 =  strongly agree) was used to perceive responses from participants. Additionally, a scale reliability test was conducted, and multivariate analysis of variance was performed to determine the relationship between selected dependent and independent variables. Results. The study found an overall safety climate score of 3.16 ± 0.55, indicating a moderate to high perception of safety on a scale of 1–5. Parameters such as role in the laboratory, departments/disciplines, accident experience and safety training significantly affected the safety climate score, while gender, age group, duration in university and accident witnessing did not. Conclusion. Upper management involvement, safety communication and direct supervision are crucial for improving the safety climate of university laboratories. The study recommends the consideration of the identified significant safety climate dimensions in laboratory safety policy-making at academic institutes.

Keeping in view the structural applications of aluminum alloys, squeeze overcasting has been considered an attractive alternative to deal with the inherent casting defects at the interface region of bimetallic composites. Microstructure at the joint interfacial region highly depends on the casting parameters. For this reason, the current study has considered the most effective parameters including melt temperature, insert preheat temperature, squeeze pressure, pressure duration and time delay to fabricate the defect-free Al2026/Al–4.5%Cu composite. Besides this, the influence of aging treatment with 5%HCl solution quenching has been investigated on yield strength, ultimate tensile strength, percentage elongation and microhardness of interfacial region of the bimetallic joint. Results of the current study show that the melt temperature and squeeze pressure are the most influential parameters to boost mechanical properties. Metallographic analysis based on SEM shows that the optimum set of input parameters (MT= 800 °C, IT= 250 °C, SP= 100 MPa, PD= 150 s, TD= 10 s) offers the strong metallurgical bond between melt and solid insert without any inherent casting defects such as micro-cracks, gas porosity, pinholes, shrinkage voids and hot tearing. EDS analysis depicts that zinc coating is highly concentrated at the interfacial region which facilitates the formation of strong metallic bonding between distinct metals.

The exponential rise of healthcare problems like human aging and road traffic accidents have developed an intrinsic challenge to biomedical sectors concerning the arrangement of patient-specific biomedical products. The additively manufactured implants and scaffolds have captured global attention over the last two decades concerning their printing quality and ease of manufacturing. However, the inherent challenges associated with additive manufacturing (AM) technologies, namely process selection, level of complexity, printing speed, resolution, biomaterial choice, and consumed energy, still pose several limitations on their use. Recently, the whole world has faced severe supply chain disruptions of personal protective equipment and basic medical facilities due to a respiratory disease known as the coronavirus (COVID-19). In this regard, local and global AM manufacturers have printed biomedical products to level the supply–demand equation. The potential of AM technologies for biomedical applications before, during, and post-COVID-19 pandemic alongwith its relation to the industry 4.0 (I4.0) concept is discussed herein. Moreover, additive manufacturing technologies are studied in this work concerning their working principle, classification, materials, processing variables, output responses, merits, challenges, and biomedical applications. Different factors affecting the sustainable performance in AM for biomedical applications are discussed with more focus on the comparative examination of consumed energy to determine which process is more sustainable. The recent advancements in the field like 4D printing and 5D printing are useful for the successful implementation of I4.0 to combat any future pandemic scenario. The potential of hybrid printing, multi-materials printing, and printing with smart materials, has been identified as hot research areas to produce scaffolds and implants in regenerative medicine, tissue engineering, and orthopedic implants.