The weight of the car material plays an important role in its performance in terms of fuel efficiency, speed and smoke emission. Especially in hybrid electric vehicles, lightweight materials are ...important for balancing the weight of its electrical components and also to enhance vehicle speed on account of its comparative low mileage. Nowadays, aluminium, magnesium and Carbon Fibre Reinforced Composites (CFRP) were introduced in making of car body panels since those materials can improve its performance. Yet the material costs, fibre orientation and fabrication techniques in case of CFRP in mass production remains a question. Also, the interior of the car panels was filled with vibration barriers or isolators with considerable thickness which can also add weight to the car. Hence a sandwich structure is presented in this work where the polyurethane foam of higher thickness (core) is bonded between two thin metallic face sheets (skin). The polyurethane foam was chosen as the core because of its low density, porosity and viscoelastic behaviour where it can provide better damping capabilities. Hence, the foam can also help in reducing the volume of internal vibration isolators. Since the car bonnet receives the vibration from sources like aerodynamic exposure to air during travel and mechanical movements within the vehicle (engine operation), it was chosen as the subject for vibration analysis.
The cooling method employed in machining processes plays a vital role in the surface quality and the efficiency of the process. Dry machining is being performed for flat milling operation on LM-4 ...alloy. This has resulted in poor surface roughness and increased tool wear rate. The other type of cooling installed in the industry is the flood coolant method which uses enormous coolant flow rate. Hence the scope of our project is to enhance the surface finish with reduced coolant flow rate and tool wear rate by introducing the Minimum Quantity Lubrication system which sprays a mixture of compressed air and lubricant in a form of mist at the point of operation i.e. tool workpiece interface. The optimized air pressure, siphon height and coolant concentration ratio are determined based on the results obtained from the surface roughness tests and the coolant flow rate measurements. Both single objective and multi objective optimization are done with the help of Taguchi analysis and Grey relational analysis respectively. Finally, this optimized MQL system is implemented in the Industry and its results are found to be in tune with our project outcome.
In recent years, stringent requirements of material quality in automotive and aerospace industries have necessitated the development of lightweight aluminum alloys. In this context, it is known that ...the metal–matrix composites offer a spectrum of advantages that are important for their selection and use as structural materials. A few such advantages include the combination of high strength, high elastic modulus, high toughness and impact resistance, low sensitivity-to changes in temperature or thermal shock, high surface durability, low sensitivity to surface flaws, high electrical and thermal conductivity, minimum exposure to the potential problem of moisture absorption resulting in environmental degradation, and improved fabricability with conventional metal working equipment Metal matrix composites (MMC) are generally produced either by liquid metallurgy or powder metallurgy techniques. Stir casting is one of the most inexpensive tools for the production of particulate metal matrix composites . It is simplest and most commercially used technique for casting MMCs. This involves incorporation of ceramic particulate into liquid aluminum alloy in molten state and allowing the mixture to solidify. Here, the crucial thing is to create good wetability between the particulate reinforcement and the liquid aluminum alloy. In this proposed work , composites of Al7075 with SiC were fabricated using Stir casting method by using both upward and downward pouring methodology .The main objective of this research work are to achieve uniform distribution of SiC particles in the aluminum alloy matrix , characterization and analysis of mechanical properties of composites formed . Experiments were carried out with different stirring speeds and specimen of different %wt of SiC were cast . Microstructure , Tensile strength and hardness values were found by conducting the corresponding tests and results were analyzed and compared . Key words - MMCs , Stir casting , Wire cut EDM , SiC reinforced metal matrix composites
Development of Amphi-Elliptical Bicycle M, Ajin; S Jospher, Abraham J; N, Vinoth Babu ...
International journal of engineering trends and technology,
11/2021, Volume:
69, Issue:
11
Journal Article
This present study focuses on evaluation of mechanical properties of three dimensional (3D)-printed carbon fiber/polylactic acid (CF/PLA) composites, using fused deposition modeling (FDM) technique. ...The composites were prepared with different slicing parameters: layer heights or thicknesses, infill densities and layer patterns. The 3D-printed composite samples were subjected to tensile, flexural and interlaminar shear strength (ILSS) tests to assess the influence of the process parameters on their mechanical characteristics. Further investigations were carried out to evaluate the effect of surface roughness of the samples. From the test results, it was evident that both rectilinear and hexagonal layer patterns exhibited better mechanical properties at infill density and layer thickness of 60% and 0.64 mm, respectively. The scanning electron microscopy (SEM) images depicted that lesser layer thickness produced poor CF/PLA interfacial bonding and major failure mode was traced to fiber pull-out. Therefore, engineering application of the composite samples depends on their slicing parameters.
The present study was designed to evaluate the phytochemical analysis and antibacterial activity of Swietenia mahagoni leaf extract. The leaf extract was subjected to a variety of phytochemical ...analysis. The qualitative phytochemical tests exhibited the presence of common phytocompounds like alkaloids, tannins, saponins, phlobatannins, flavanoids, terpenoids and volatile oils as major active constituents. The plant (Swietenia mahagoni) leaf has valuable medicinal uses, hence petroleum ether (18.2g) was found to be a good solvent for the phytochemical and antibacterial study. Similarly, the Methanolic leaf extract of Swietenia mahagoni has highest zone of inhibition on Bacillus subtilis.
Heat shock protein information resource (HSPIR) is a concerted database of six major heat shock proteins (HSPs), namely, Hsp70, Hsp40, Hsp60, Hsp90, Hsp100 and small HSP. The HSPs are essential for ...the survival of all living organisms, as they protect the conformations of proteins on exposure to various stress conditions. They are a highly conserved group of proteins involved in diverse physiological functions, including de novo folding, disaggregation and protein trafficking. Moreover, their critical role in the control of disease progression made them a prime target of research. Presently, limited information is available on HSPs in reference to their identification and structural classification across genera. To that extent, HSPIR provides manually curated information on sequence, structure, classification, ontology, domain organization, localization and possible biological functions extracted from UniProt, GenBank, Protein Data Bank and the literature. The database offers interactive search with incorporated tools, which enhances the analysis. HSPIR is a reliable resource for researchers exploring structure, function and evolution of HSPs.
http://pdslab.biochem.iisc.ernet.in/hspir/
Fiber/metal hybrid composites are perceived as superior materials for applications in machine tools because of their enhanced machinability, lightweight nature, and vibration-damping capabilities. ...The application of AWJM to hybrid composites introduces challenges, including kerf convergence ratio and surface irregularity issues throughout the machining process. This study is all about the AWJM of a Kevlar fiber/SS wire mesh epoxy composite with silicon carbide filler particles and garnet as the abrasive material. The study aims to investigate the effects of varying machining conditions, such as cutting velocity, abrasive performance rate, and nozzle tip distance, and to determine the most effective machining parameters using TOPSIS technique. To achieve this, a total of 27 different experimental trials were conducted, and two key attributes, namely kerf convergence ratio and surface irregularity, were recorded. This approach empowers all-encompassing evaluation and comparison of diverse machining parameter combinations, thus expediting the selection of the most fitting parameters to attain desired machining outcomes.
The right timing of animal physiology and behaviour ensures the stability of populations and ecosystems. To predict anthropogenic impacts on these timings, more insight is needed into the interplay ...between environment and molecular timing mechanisms. This is particularly true in marine environments. Using high-resolution, long-term daylight measurements from a habitat of the marine annelid Platynereis dumerilii, we found that temporal changes in ultraviolet A (UVA)/deep violet intensities, more than longer wavelengths, can provide annual time information, which differs from annual changes in the photoperiod. We developed experimental set-ups that resemble natural daylight illumination conditions, and automated, quantifiable behavioural tracking. Experimental reduction of UVA/deep violet light (approximately 370-430 nm) under a long photoperiod (16 h light and 8 h dark) significantly decreased locomotor activities, comparable to the decrease caused by a short photoperiod (8 h light and 16 h dark). In contrast, altering UVA/deep violet light intensities did not cause differences in locomotor levels under a short photoperiod. This modulation of locomotion by UVA/deep violet light under a long photoperiod requires c-opsin1, a UVA/deep violet sensor employing G
signalling. C-opsin1 also regulates the levels of rate-limiting enzymes for monogenic amine synthesis and of several neurohormones, including pigment-dispersing factor, vasotocin (vasopressin/oxytocin) and neuropeptide Y. Our analyses indicate a complex inteplay between UVA/deep violet light intensities and photoperiod as indicators of annual time.
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