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Mechanical And Water Absorption Behavior Of Natural Fibers Reinforced Polypropylene Hybrid Composites
No full textFrom the past decades, abundant usage of natural fibers is observed in polymeric composites due to factors like natural
availability, cost economy, low density compared to synthetic fibers, easy processing and biodegradability. Coastal regions of
India including Andhra Pradesh and Tamil Nadu are well known for immense plantations of Banana fiber (BF) and coconut fiber
(CF) trees.The stem portion of these plantations are usually discarded as waste. This study evaluated usage of this fibrous waste from banana and coconut plantations as reinforcement in thermoplastic polypropylene(PP) to form a hybrid composite structure. This study aims to reduce the cost of conventional plastics by utilizing the optimal quantity of natural fiber reinforcement. Issues such as water absorption and fiber/matrix delamination of natural fiber reinforcements are considered for obtaining better application characteristics. The samples of BF/CF reinforced polypropylene hybrid composite are manufactured using twin screw extruder and injection moulding machines at different fiber loadings(CF/BF/PP)of 15/5/80, 10/10/80 and 5/15/80 wt.%. The effect of fiber loading on hybrid composites is studied. The mechanical properties such as tensile strength, flexural strength and impact strength of the resultant hybrid composites are optimized based on fiber loading. The moisture absorption characteristics of the hybrid materials are also evaluated
Temperature-Stable Compelled Composite Superhydrophobic Porous Coordination Polymers Achieved via an Unattainable de Novo Synthetic Method
Get PDFWe demonstrate a new de novo synthetic methodology to achieve high-temperature-stable compelled composite superhydrophobic porous coordination polymers (PCPs). These new PCPs were achieved based on coordination capabilities of first-row transition metal ions such as Co2+, Ni2+, and Zn2+. The obtained composite PCPs containing a [Zn2M2O]6+ (M = Co or Ni) bimetallic cluster core with open metal sites (OMSs) exhibited distinct isosteric heats of adsorption and surface areas due to the difference in their open metal Lewis acidic sites of solvent-free state. Additionally, these composite PCPs exhibit remarkable superhydrophobic properties with contact angles of 159.3° and 160.8° respectively for Zn–Co and Zn–Ni analogues. This superhydrophobic surface survives even at high temperature for longer time periods. As projected, these new composite PCPs exhibit better surface area and heats of adsorption compared to the PESD-1 (Zn) analogue due to a larger number of OMSs. Moreover, they display selective adsorption toward aromatic solvents such as benzene and toluene over aliphatic solvents such as cyclohexane due to corrugated and terminated aromatic hydrocarbon moieties toward the interactive surface. They also exhibit oil spill cleanup from the water surface in the powder form as well as pellet form up to 385 wt %. This study certainly offers a roadmap for designing and engineering new composite superhydrophobic porous materials for better water and thermal stability along with OMSs. This type of PCP exhibits a wide range of applications especially in catalysis, separation technology, and securing environmental problems such as oil spill cleanup in seawater
Variation in properties of tender jackfruit during different stages of maturit
Get PDFThis research was conducted on two varieties of tender jackfruit [hard (HV) and soft variety (SV)]. The tender jackfruit was divided into four stages (i.e. Stage 1, 2, 3 and 4) and their physical, mechanical, chemical and textural properties were determined for both the varieties. Physical properties like weight, length, diameter, geometric mean and arithmetic mean diameter were increases with increase in size for both the varieties. There was a significant increase in TSS in both the varieties (HV: 1.5 ± 0.02 to 5.1 ± 0.03; SV: 2.7 ± 0.05 to 7.1 ± 0.05 oBrix) from stage 1 to 4 because of ripening of fruit. The hardness, fracturability and springiness increases with maturity but on the counterpart, there is a decrease in adhesiveness, cohesiveness, chewiness and gumminess. The nutritional properties and the energy (kj) values were inevitable increases whereas vitamins content was decreases from stage 1 to 4 in both the varieties. The measured properties will be helpful in planning, design and fabrication of post-harvest processing equipment for tender jackfruits
Quinazolin derivatives as emerging alpha-glucosidase inhibitors
Get PDFA series of C-7 substituted-2-morpholino-N-(pyridin-2-ylmethyl) quinazolin-4-amine have been synthesized and biochemical assay was examined against α-glucosidase function inhibition activity. A structure activity and structure property relationship study was experimented to surface the new hit compound. This study led to the identification of C7substituted quinazolines with minimum inhibitory concentrations (MICs) in the preffered micromolar range in addition with interesting physicochemical properties. Biological evaluation yielded eight analogs which rose with significant α-glucosidase inhibition potency (IC50 values < 2 μM, where reference compound (Acarbose) potency value is IC50 = 0.586 uM) and could be promising candidates for further lead optimization
From carbamate to chalcone: Consecutive anionic Fries rearrangement, anionic Si→C alkyl rearrangement and Claisen-Schmidt condensation
No full textABSTRACT: A highly efficient one-pot procedure was
14 developed for the synthesis of various 2′-hydroxychalcones
15 from phenyl diethylcarbamate, featuring consecutive
16 Snieckus−Fries rearrangement, anionic Si → C alkyl
17 rearrangement, and Claisen−Schmidt condensation in a single
18 operation. The applicability of this protocol was demonstrated
19 by the highly efficient synthesis of the anti-inflammatory natural product lonchocarpin. The mechanism insight is also provided
Modeling and surface texturing on surface roughness in machining LaPO4–Y2O3 composite
Get PDFIn this work the Lanthanum phosphate with 20% Yttria (LaPO4/Y2O3) composite prepared by Aqueous Sol-Gel process is machined by Abrasive Water Jet Machine (AWJM). The machiniability of this composite is studied by varying the input parameters namely Jet Pressure (JP), Stand-Off Distance (SOD) and Traverse Speed (TS) on Surface finish. Garnet of 80 mesh size is used as abrasive with a flow rate of 85 gms/min. The
micro structural characterization study reveals the presence of new element YPO4. This element enhances the machiniability and reduced porosity in the composite. Microscopy
examinations on machined surface reveals that partial overlapping at low JP, poor surface finish at high JP and SOD, Forged deficiency at maximum SOD and TS. The minimum
level of all input parameters are influenced to obtain acceptable Ra. Atomic Force Microscopy (AFM) on kerf surface shows micro wear track and peaks. The Multiple Regression Analysis (MRA) is developed for Ra to check the adequacy. From the 2
Analysis of Variance (ANOVA), SOD has the significant effect on Ra with a contribution of 53%. The influence of JP and TS on Ra is found to be 31% and 15%, respectively
A hybrid approach to multi response optimization of micro milling process parameters using Taguchi method based graph theory and matrix approach (GTMA) and utility concept,
No full textNowadays, it is required to produce micro products with high dimensional accuracy to use them in different applications like aerospace, electronic and optics. The objective of this study is to investigate influence of process parameters on surface roughness (Ra and Rq), tool wear and cutter vibration in micro milling of AISI304 stainless steel. According to orthogonal array of L27, twenty-seven experiments were conducted on the work�piece with carbide end mill cutter at different levels of spindle speeds, feeds and depth of cuts. A hybrid approach
of Taguchi method based graph theory and matrix approach (GTMA) and utility concept was used for multi response optimization of process parameters. The GTMA was used to calculate weightage of four responses as per user’s opinion or preference. The utility concept was used to calculate utility value of four responses using preference scale. Mean utility values of responses are analyzed with Taguchi method and analysis of variance. The optimum process parameters for the minimization responses were found to be 6000 rpm of spindle speed, 95 µm/teeth of feed and 50 µm of depth of cut. The predicted responses at optimal process parameters are
Ra = 0.534 µm, VB = 70.861 µm, Amp = 54.395 µm and Rq = 0.894 µm. A confirmation test was also carried out to verify the result
Modeling with multilayer perceptron for detection of fuel adulteration using python programming
No full textAdulteration of fuel is introduction of an unknown substance into motor spirit unlawfully or not permitted resulting the product does not conform to the needs and specifications. Normally cheaper boiling point range hydrocarbons having more or less similar composition are added as additives leading to alter and degrade the quality of the base fuels. This method is adopted by the trading community for their quick illegal
profits. This is coming as tail pipe exhaust in automobile lead to environmental pollution as well as human hazard. Ethanol and methanol added illegally to increase octane levels caused fuel pipes to leak exhaust. In order to detect the pollutants there shall be proper way both at laboratory level as well as statute. Artificial Neural Networks technique to analyze the fuel adulteration is a precise technique than any other existing
methods
Electrical Discharge Machining studies on Monel- Super Alloy,
No full text(EDM). EDM operation is governed by Pulse ON time, pulse OFF time, discharge current and gap voltage and they are taken as
independent parameters. Material Removal Rate (MRR) and Surface Profile (Ra) are taken as the dependent parameters. To
predict the optimal condition, the experiments are conducted by using Taguchi’s L27 orthogonal array. The influences of each
independent parameter on the dependent parameters are analysed using multi functional grey relational analysis with the
intension of increasing MRR with acceptable level of Ra. Through response table, optimized condition has been predicted. From
ANOVA, it is identified that discharge current has a significant effect on MRR and Ra with a contribution of 71% and 81%,
respectively. The experiment has been conducted to validate the optimal condition and it is found to be 99.1% acceptable level
Optimization of Input Parameters on Erosion Wear Rate of PTFE/HNT filled nanocomposites
No full textIn the current paper an extensive study on erosion wear is carried out on PTFE/HNT nanocomposites by air jet erosion tester as per ASTM G76 standard. The test is conducted on nanocomposite samples those are made with 4%, 6%, and 8% by weight of HNT in PTFE matrix. The experiments are designed in a user defined response surface methodology (RSM) and are performed on the erosion tester. The control factors used are: composition (A) with 3 levels, pressure (B) with 3 levels and impingement angle (C) with 4 levels. A full factorial design with 36 runs is planned. The results are then analyzed by using Design Expert software in response surface methodology (RSM). Analysis of variance (ANOVA) is also carried out and a quadratic model with regression equation is established. Surface plots are plotted corresponding to factors AB, BC, and AC. Conforming to the minimization of erosive wear at desirability equal to 1: 4.67% by weight HNT composition, 0.9235 bar pressure, and 900
impingement angle, a wear rate of 0.0391x10-5g/g is found. Also plots representing the effect of impingement angle and pressure
on erosion wear rate are plotted. From the plots maximum wear is found corresponding to low impingement angles and higher
operating pressure