Performance and emission characteristics of diesel fuel produced from waste plastic oil obtained by catalytic pyrolysis of waste polypropylene

Waste plastic oil derived from kaoline catalyzed pyrolysis of waste polypropylene is blended with diesel fuel, tested as an alternative fuel in a diesel engine, and its performance characteristics are analyzed and compared with diesel fuel operation. It is observed that the engine could operate with maximum 50% waste plastic oil blended diesel. An engine showed better performance up to 30% blend, but beyond 50% blend it gave a vibration. The results showed a stable performance with brake thermal efficiency similar to that of diesel and its value is higher up to 80% of full load. All emissions are considerably higher than that of the diesel baseline especially at high load and blend.     

Influence of heat input on microstructure and fracture toughness property in different zones of X80 pipeline steel weldments

In this paper, microstructure observations and mechanical behaviour of fusion line and offsetting positions from fusion line by 1, 2 and 3 mm were analysed. For the welding of X80 pipeline steel plates, different magnitudes of heat inputs such as high heat input (HHI) 25 kJ/cm, medium heat input (MHI) 20 kJ/cm and low heat input (LHI) 15 kJ/cm were employed. Critical values of J‐integral (J_0.2) and crack tip opening displacement (CTOD_0.2) for predetermined regions in the X80 weldment were determined as per ASTM‐E1820a. M‐A constituents of different sizes such as small (1–2 μm), large >2 μm and slender (>4 μm) were observed in the microstructure of subzones of weldments for different heat inputs. Formation of granular bainite, M‐A constituents and inclusions of Ti, Si, Mo in the microstructure impaired fracture toughness property. In the X80 weldment, the fusion line (FL) for HHI was found weakest in terms of fracture resistance, which subsequently increases the risk of fracture.     

Pd Nanoparticles and Thin Films for Room Temperature Hydrogen Sensor

We report the application of palladium nanoparticles and thin films for hydrogen sensor. Electrochemically grown palladium particles with spherical shapes deposited on Si substrate and sputter deposited Pd thin films were used to detect hydrogen at room temperature. Grain size dependence of H₂ sensing behavior has been discussed for both types of Pd films. The electrochemically grown Pd nanoparticles were observed to show better hydrogen sensing response than the sputtered palladium thin films. The demonstration of size dependent room temperature H₂ sensing paves the ways to fabricate the room temperature metallic and metal–metal oxide semiconductor sensor by tuning the size of metal catalyst in mixed systems. H₂ sensing by the Pd nanostructures is attributed to the chemical and electronic sensitization mechanisms.     

Phase transfer catalysis of alkaline hydrolysis of n-butyl acetate: Comparison of performance of batch and micro-reactors

The hydrolysis of n-butyl acetate with aqueous sodium hydroxide was studied in the batch mode as well as in the continuous mode in a micro-reactor. The progress of the reaction was analyzed both with and without a phase transfer catalyst. The concentration of the unreacted sodium hydroxide in the aqueous phase was determined by titration with hydrochloric acid to monitor the progress of the reaction. The performance of the two systems is studied for different operating conditions, i.e. concentrations of reactants, stirring speeds (in batch mode) and flow rates (in continuous mode). Conditions are identified when the performance of the micro-reactor system is superior to that of the batch system. To understand this better the performance of a 1 mm channel and a 0.4 mm channel are compared with that of the batch reactor.     

Rapid Microwave‐Assisted Solvothermal Synthesis of Methanol Tolerant Pt–Pd–Co Nanoalloy Electrocatalysts

We report here a microwave‐assisted solvothermal (MW‐ST) method to synthesise carbon‐supported multimetallic nanostructured alloys of Pt, Pd and Co with high crystallinity and homogeneity for electrocatalytic application in fuel cells. Multimetallic nanoalloy electrocatalysts have been synthesised by a one‐pot, rapid MW‐ST method within 15 min at <300 °C without any post‐annealing in reducing gas atmospheres. For a comparison, same multimetallic alloys were also synthesised by heat treatment of co‐precipitated metals. Significant differences were observed in the phase structure and surface composition of the alloys synthesised by the two methods, which were rationalised based on the synthesis procedures adopted. Further, the multimetallic alloys were also explored for their electrocatalytic applications as cathode catalysts for oxygen reduction reaction (ORR). The multimetallic alloys, synthesised by the MW‐ST method, show much higher ORR activity compared to their counterparts synthesised by the conventional borohydride reduction method. While the ORR activity of Pt₇₀Pd₂₀Co₁₀ is comparable to that of commercial Pt, the ORR activity of Pt₅₀Pd₃₀Co₂₀ in direct methanol fuel cells (DMFC) is superior to that of commercial Pt at high methanol concentrations due to its high tolerance to methanol that may crossover from the anode to the cathode.     

Low-frequency ferroelectric switching studies in PVDF thin films across Cu or (Ag/Cu)/PVDF/Cu capacitor structures

Ferroelectric switching dynamics of polyvinylidene fluoride (PVDF) thin films in Cu or (Ag/Cu)/PVDF/Cu capacitors are explored by varying PVDF film thickness, applied electric field amplitude (4.35–87.5 MV/m) and frequency (100 mHz–200 Hz). Comprehending spontaneous polarization and its dependence upon interfaces, an electric field is critical for organic ferroelectric memory devices. In this article, quasi-static current–voltage, and polarization–electric field measurements are used to explain the relationship between the coercive field, signal amplitude, and frequency. The observed coercivity enhancement at lower PVDF film thicknesses and with rising frequencies of the applied signal is discussed with Kolmogorov-Avrami-Ishibashi domain nucleation and growth model. The relation between domain growth and the top electrode layer is further discussed from the exponent parameters.     

Optimization of Tribological Properties in Aluminum Hybrid Metal Matrix Composites Using Gray-Taguchi Method

This article investigates the optimization of dry sliding performances on the aluminum hybrid metal matrix composites using gray relational analysis in the Taguchi method. Different loads, sliding speeds and varying percentage of molybdenum disulfide are selected as control factors. The multiple responses to evaluate the dry sliding performances are specific wear rate and coefficient of friction. Using a pin-on-disk apparatus, the volume loss and frictional force are measured. Based on gray relational analysis, the optimum level parameters for specific wear rate and coefficient of friction have been identified. An L27 orthogonal array was employed for the experimental design. Analysis of Variance (ANOVA) had given the impact of individual factors and interactions on the specific wear rate as well as the coefficient of friction. The results indicated that the three test parameters had a significant role in controlling the friction and wear behavior of composites. Interaction of the control factors showed the sizable influence on tribological performance. Using Scanning Electron Microscopy (SEM) the wear surface morphology and wear mechanism of the composites have been investigated.     

Laboratory Studies on Membrane Deoiling of Lecithin

Deoiling of lecithin using a nonporous membrane was examined in a favorable solvent (hexane) medium with soy and rice bran lecithins. During the membrane process, the acetone insoluble (AI) content of soy lecithin increased from 63.2 to 81.0% in a single step batch operation. The membrane exhibited an excellent selectivity since phospholipid (PL) reverse micelles formed in the system were rejected almost completely due to low solubility probably aided synergistically by size exclusion. Diafiltration achieved greater oil removal from lecithin as reflected in terms of higher AI and PL contents in the deoiled lecithin. In discontinuous diafiltration, the PL content increased from 33.3 to 85.5% in rice bran lecithin (150% dilution to feed) and 56.6 to 85.7% in soy lecithin (200% dilution), respectively. The simulated continuous diafiltration run showed slightly greater PL content in soy lecithin (91.3%) compared to discontinuous diafiltration (89.7%) besides offering higher productivity. The membrane showed a color reduction of ~60% in soy lecithin but there was no improvement in rice bran lecithin due to the retention of degradation products. The proposed integrated membrane process with nonporous (deoiling) and nanofiltration (solvent recovery) membranes could be an attractive preposition besides being an acetone free process.     

Effects of sintering temperature on structural and electromagnetic properties of MgCuZn ferrite prepared by microwave sintering

Nanocrystalline magnesium–copper–zinc (Mg_0.30Cu_0.20Zn_0.50Fe₂O₄) ferrites were prepared by microwave sintering technique. The effects of the sintering temperature on particle size and magnetic properties were investigated. In this article, optimum sintering temperature required for MgCuZn ferrite system for obtaining good electromagnetic properties, suitable for applications in low temperature co-fired ceramics (LTCC) chip components was studied. The grain size, initial permeability, dielectric constant and saturation magnetisations were found to increase, and dielectric loss was found to decrease with the increasing sintering temperature. Mg–Cu–Zn ferrites with a permeability of μ?=?1110 (at 1?MHz) were fully densified at the standard LTCC sintering temperature of 950°C.