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Experimental analysis of Moringa leaf thin layer drying modeling
Get PDFThe use of synthetic antioxidants is limited due to their toxic properties. The purpose of this study is to study the antioxidant activity of medicinal and aromatic plant extracts and to identify alternative natural and safe sources of food antioxidants, especially of vegetable origin. Research work was conducted to study the rehydration of various temperatures and dried moringa leaves. The moringa leaves are widely known for their cosmetic properties, which have anti-carcinogenic, antiinflammatory, analgesic and antipyretic properties. To study the effect of different drying conditions on the kinetics of moringa leaves, they were dried at 50, 60 and 70 °C. The drying of the Moring leaves was visible during the fall rate and at higher temperatures the drying was faster. Among the mathematical models studied, the Newtonian model has satisfactorily characterized the resistance to drying with the highest values of r2. The actual moisture diffusivity of the Moring leaves increases as the temperature of the drying air increases
Design and development of polybenzoxazine-POSS hybrid materials from renewable starting materials for low k and low surface free energy applications
No full textAbstract
The introduction of nano-sized polyhedral oligomeric silsesquioxane (POSS) derivatives into polymer matrices have received significant interest in recent years mainly because of the inherent properties of POSS which include low coefficient thermal expansion, low density, low thermal conductivity, low dielectric constant, high oxidation resistance, and low the surface free energy. In view of this, an attempt has been made to develop thermally stable, flame retardant, low dielectric, and lower surface free energy polybenzoxazine-POSS (PBz-POSS) hybrid prepared using renewable agro-waste (cardanol, furfurylamine and stearylamine) as starting materials. A new approach involving thiol-ene click reaction has been adopted to introduce mercapto functional POSS (SH-POSS) into cardanol benzoxazines (Bz-C-F and Bz-C-S). The thermal, dielectric, flame-retardant, and contact angle studies of the prepared PBz-POSS hybrids were investigated using modern characterization techniques. The results from thermal, flame, dielectric and water contact angle studies clearly indicate that the developed renewable, cost�effective and eco-friendly PBZ-POSS hybrid materials can be exploited as coatings and sealants
as well as for low dielectric microelectronic applications to substitute the currently used petroleum-based raw materials
Compounding and the mechanical properties of catla fish scales reinforced-polypropylene composite–from biowaste to biomaterial
No full textIn this study, bio-waste catla fish scale (CFS) was used as a reinforcing agent in polypropylene (PP) for the fabrication of biomaterials by using a twin-screw extrusion technique. Tensile strength, elongation-at-break and heat deflection temperature
(HDT) of the composites decreased upon the addition of CFS, however, Young’s modulus improved, significantly. The flexural strength, density, and hardness of the composites increased by 5%, 1%, and 11%, respectively, with increasing the CFS
content. The impact strength and the melt flow index (MFI) noticeably increased with increasing CFS loading. These results signified the fact that the CFS/PP composites from CFS biowaste showed improved mechanical properties and it can be a potential alternative biomaterial for various biomedical applications. In addition, the applica�tion of CFS as a filler in polymers can be viewed as a sustainable approach that
incorporates biowaste-based value-added material and can simultaneously mitigate the sewage problems in a smart manner in the marine environment
Drilling study on lightweight structural Mg/SiC composite for defence applications
No full textHeat energy generated during machining has been found to have a greater influence on determining the machinability of the materials. In this work, magnesium-based silicon carbide composite, which has been identified as a suitable lightweight application material, is prepared with the weight ratio of 90:10 by a stir casting process. Conventionally available HSS drill tools with different diameters of 4, 6 and 8 mm are used to perform the drilling operations with governing parameters of spindle speed, feed rate and constant depth of cut. Thermal image camera of the FLIR E60 series is used to measure the temperature variation in the cutting zone at different operating conditions. The influences of machining temperature
on chip morphology, tool wear and surface profile of the machined samples are investigated. Spindle speed has been found to have a significant effect on machining temperature. When spindle speed in�creases, the diameter of drill tool increases the tool wear and surface profile, respectively. Both abrasion and adhesive type of wears are observed in the drill tool. Further, change from abrasion to adhesive wear
is noticed with the increase of the diameter of the drill tool. Surface plots are drawn with respect to the interaction of governing parameters along with the working temperatures obtained under different machining conditions
Acoustic emission signature analysis on rolling element bearings due to localized defects
No full textThe interaction of surface asperities and
impingement of rolling element of bearing over the
defective races of rolling element bearings generate
Acoustic Emissions (AEs). Significant progress in the
capabilities of acoustic instrumentation, together with
signal processing techniques, made possible to extract
useful diagnostic information from acoustic signals. The
main advantage of AE is that it offers high Signal to Noise
Ratio (SNR), which is required for the precise detection of
faults. Rotating speed, radial load and size of localized
defect are the most influenced operating parameters on AE
amplitude. A bearing test-rig is designed and established to
study the various defect sizes on outer race of rolling
element bearings. AE signal generated from artificial line
defects in rolling element bearings (REBs) are
investigated. The AE signal was transformed through Fast
Fourier Transform (FFT) AE laboratory software, which is
supplied by AE instrument. Even though there were many
signatures of AE signals that can be used such as
amplitude, duration, counts and signal energy. AE
instrument with amplitude is used in this study, which
allows for the measuring of amplitude in the signal.
Experiments are performed using N312 REBs and results
have been presented. Experimental data is analyzed using
response surface methodology (RSM) to identify the
significant parameters on AE amplitude. Here, predictive
model like RSM is used to predict and optimize AE
amplitude in dB leve
Fabrication and characterization of S glass hybrid composites for Tie rods of aircraft
No full textcombination of 7-mill glass fabric, ceramic paper as intermediate and carbon fabric. The ceramic papers which acted as intermediate layers are treated with a mixture of short carbon fibers and carbon powder along with epoxy, epoxy terminated butadiene acrylonitrile (ETBN) and room temperature hardener. The composites are fabricated using Hand lay-up process and solidification of material is obtained through high temperature oven. Further these composite materials are machined to obtain required dimensions as per the design of shield for Tie-rod and splitter rod by considering Radar Cross Section calculation.
Flexural and Inter Laminar Shear Strength (ILSS) tests were performed on S-Glass epoxy composite before
and after machining. Flexural and Inter Laminar Shear Strength (ILSS) tests were considered in fabrication
of Radom structures. Deviations observed in ILSS are around 3% to 18% and deviations observed in
Flexural tests are 16% to 23%. In Flexural tests, the samples after machining have positive affect.
Whereas, in ILSS tests, the machined samples have least effect. The tests obtained in S-Glass epoxy composite
before and after machining were in allowable deviations.
� 2019 Elsevier Ltd. All rights reserved
Optimisation of Dyeing and Mordanting Parameters on Cotton Fabrics Treated With Allium Cepa as a Natural Dye Source
Get PDFOnion peel is having rich source of colorant and found to be waste in large quantities. This can be used for dyeing of textile materials as a sustainable eco-friendly approach. In the present study cotton fabrics were dyed with onion peel dye extracted by using Soxhlet apparatus. Four different mordants like Amla, Myrobalan, Pomegranate Rind and Chitosan were used in different concentrations in order to optimize the right combination. Design of experiment was used for selection of various combinations in order to carry out dyeing process. The color strength was measured using spectrophotometer and also measured the fastness properties of dyed samples. Out of four different mordants chitosan was found to be showing highest K/S values in pre-mordanting method. Fastness properties for almost all the samples were found to be average
First Ply Failure Analysis of Rectangular Fiber Metal Laminated Composite Plates Subjected to Uniformly Distributed Loads
Get PDFFiber metal laminates (FMLs) are the hybrid composite materials that needed analysis for using them toward applications as rectangular plates subjected to uniformly distributed loads. Determination of first ply failure (FPF) loads is the focus of the present study. These loads are identified by the procedure developed on the basis classical laminate theory (CLT), and Tsai–Hill criterion is used to identify the failure load. The developed procedure was validated by applying it to the standard cases reported in the literature. The failure loads and deformation of FMLs are presented in the form of dimensionless parameters, and their variation was studied for width-to-length ratios. FMLs of GLARE and Ti-CFRP are studied based on their importance to research
Effect of Yttrium (20%) doping on mechanical properties of rare earth nano lanthanum phosphate (LaPO4 ) synthesized by aqueous sol-gel process,
No full textIn this study, Nascent Lanthanum Phosphate (LaPO4) and LaPO4 with 20% reinforced Yttria (Y2O3) precursor ceramic powder was synthesized through aqueous Sol-gel route, where theLaPO4 and LaPO4/Y2O3 powder was sourced from Lanthanum chloride (LaCl3) and orthophosphoric acid (H3PO4). By sintering the precursor powder at 1400 °C for 2 h, a relatively high-density composite material of LaPO4 (97.4%) and LaPO4/Y2O3 (98.4%) were fabricated. Through X-ray powder diffraction (XRD) experiment, the results revealed that LaPO4 and LaPO4/ Y2O3 electrolyte samples sintered at 1400 °C for 2 h is impurity free and thereby elemental composition of the
powders is also verified. Further, a small quantity of LaP2 and La2O3elements formed during the synthesis of LaPO4 was found to contribute more on corrosion resistance and high withstanding capacity of the material. 26% of YPO4 formed due to a chemical reaction between Yttrium and Lanthanum made this composite a suitable candidate material for high-temperature applications. Various mechanical characterization tests such as microhardness, flexural strength, and compression capacity were studied, where the microscopic analysis provided
comprehensive information about both transgranular and intergranular types of failure on the fractured regions
of LaPO4 and LaPO4/Y2O3 material. The MicroVicker'shardness of LaPO4 and composite was found to be 5 GPa and 5.2 GPa, respectively. When compared with the nascent sample, on an average, 22% reduction in flexural strength and a 1.05% increase in Young's modulus are observed for the high-density composite
A study on performance characteristics and multi response optimization of process parameters to maximize performance of micro milling for Ti-6Al-4V
No full textIn machining of hard metals, surface roughness, tool vibration and tool wear are used as performance
characteristics to estimate overall performance of process. This work is aimed to maximize overall
performance in micromachining of Ti-6Al-4V and investigate effect of process parameters on perfor�mance characteristics. As per orthogonal array of L27, twenty seven experiments are carried out on the
proposed metal with cemented carbide tools at three levels of cutting speed, feed and depth of cuts.
According to user's preference rating, graph theory and matrix approach is used to estimate weights and
preference scales for the performance characteristics. Utility concept is used to calculate overall performance of the process using weights and preference scales. Responses surface methodology is used to optimize process parameters to maximize overall performance of the process. In this study, maximum performance of the process is found at cutting speed of 19.78 m/min, feed of 75 mm/tooth and depth of
cut of 50 mm. In addition to that, metal recovery in machining due to elastic recovery is also estimated theoretically and measured practically for different uncut chip thicknesses