Studies on pyrolytic conversion of waste plastic carry bags into plastic crude oil

The utilization of plastic carry bags in our modern life is increasing every year and also increasing pressure on safe disposal of these bags. Worldwide the disposal of these kinds of plastic wastes is becoming serious issue due to their non-degradable nature. The main aim of this study is to exploit the potential of waste plastic carry bags for the production of plastic crude oil by using non-electric pyrolytic unit. The heat required for pyrolysis process supplied from biomass gas stove and coconut shell used as combustible fuel. To optimize the heating conditions for higher plastic crude oil recovery, different quantities of coconut shell were utilized and the maximum recovery of plastic crude oil was recorded. The yield of crude oil ranged from 34.5 to 40.7 per cent for the reaction temperature ranged from 457 to 517 °C. For 4 kg fuel supplied as heating source, the crude oil recovered was 40.7 per cent at a reaction temperature of 486 oC and residence time of 58 min. The calorific value of the waste plastic carry bags and plastic crude oil was found to be 34.4 and 38.6 MJ/kg, respectively

Novel Fabrication of Un-coated Super-hydrophobic Aluminum via Pulsed Electrochemical Surface Modification

AbstractSuper-hydrophobic and super-hydrophilic aluminum (Al) surfaces were fabricated via electrochemical surface modification (ECSM) in neutral NaClO3 electrolyte without the addition of secondary chemical coatings. The effects of processing time and applied potential on the surface roughness and wettability were studied. The aluminum surface was characterized using stylus profilometer and scanning electron microscope (SEM). Wettability was evaluated using Sessile Drop Test and a high resolution camera. Results show that surfaces obtained hierarchical rough features and super-hydrophilic behavior after pulse electrochemical machining. Heat treatment at 200°C transitioned the substrates to exhibit super-hydrophobic behavior due to the removal of all moisture from within the micro- and nano-meter scale features on the aluminum surfaces, allowing for the reformation of a natural passivation (oxide) layer with atmospheric interaction. The method proposed in this study for producing super-hydrophobic aluminum surfaces does not require the use of acid or base etching or chemical coatings, such as flouroalkylsilane (FAS). Experimental results reveal increase in contact angle, with increase in applied potential, and decrease in sliding angle

Design of an electrochemical micromachining machine

Electrochemical micromachining (μECM) is a non-conventional machining process based on the phenomenon of electrolysis. μECM became an attractive area of research due to the fact that this process does not create any defective layer after machining and that there is a growing demand for better surface integrity on different micro applications including microfluidics systems, stress-free drilled holes in automotive and aerospace manufacturing with complex shapes, etc. This work presents the design of a next generation μECM machine for the automotive, aerospace, medical and metrology sectors. It has three axes of motion (X, Y, Z) and a spindle allowing the tool-electrode to rotate during machining. The linear slides for each axis use air bearings with linear DC brushless motors and 2-nm resolution encoders for ultra precise motion. The control system is based on the Power PMAC motion controller from Delta Tau. The electrolyte tank is located at the rear of the machine and allows the electrolyte to be changed quickly. This machine features two process control algorithms: fuzzy logic control and adaptive feed rate. A self-developed pulse generator has been mounted and interfaced with the machine and a wire ECM grinding device has been added. The pulse generator has the possibility to reverse the pulse polarity for on-line tool fabrication.The research reported in this paper is supported by the European Commission within the project “Minimizing Defects in Micro-Manufacturing Applications (MIDEMMA)” (FP7-2011-NMPICT- FoF-285614)

Design of a pulse power supply unit for micro-ECM

Electrochemical micro-machining (μECM) requires a particular pulse power supply unit (PSU) to be developed in order to achieve desired machining performance. This paper summarises the development of a pulse PSU meeting the requirements of μECM. The pulse power supply provides tens of nanosecond pulse duration, positive and negative bias voltages and a polarity switching functionality. It fulfils the needs for tool preparation with reversed pulsed ECM on the machine. Moreover, the PSU is equipped with an ultrafast overcurrent protection which prevents the tool electrode from being damaged in case of short circuits. The developed pulse PSU was used to fabricate micro-tools out of 170 μm WC-Co alloy shafts via micro-electrochemical turning and drill deep holes via μECM in a disk made of 18NiCr6. The electrolyte used for both processes was a mixture of sulphuric acid and NaNO3 aqueous solutions.The research reported in this paper is supported by the European Commission within the project “Minimizing Defects in Micro-Manufacturing Applications (MIDEMMA)” (FP7-2011-NMP-ICT-FoF-285614

An approach to determine crystalline content of Granisetron in transdermal patches using X-ray diffraction technique

Granisetron is a drug used to treat nausea and vomiting after chemotherapy. Crystallization of drug is always a major concern in the transdermal drug delivery system. In view of consistent biopharmaceutical performance, monitoring and controlling the crystallization during product development and shelf life is very important. The need was felt to have an accurate method for determination of crystallinity in transdermal patches.The present study is about development and validation of a quantitative X-ray diffraction method for the determination of the extent of crystallization of the drug in transdermal formulation of Granisetron. Specimens of different physically spiked concentrations were carefully prepared accurately by weighing and distributing crystalline active pharmaceutical ingredient (API) onto placebo liner patches, pasted on Silicon low background sample holder (diameter of 24.5 mm, made up of Si crystal). All the specimens thus prepared were scanned using optimized instrumental parameters while enabling specimen rotation during the diffraction analysis to ensure homogeneous exposure to the incident X-rays. Using this novel approach, limit of detection

Formation and stability of equiatomic and nonequiatomic nanocrystalline CuNiCoZnAlTi high-entropy alloys by mechanical alloying

Nanocrystalline equiatomic high-entropy alloys (HEAs) have been synthesized by mechanical alloying in the Cu-Ni-Co-Zn-Al-Ti system from the binary CuNi alloy to the hexanary CuNiCoZnAlTi alloy. An attempt also has been made to find the influence of nonequiatomic compositions on the HEA formation by varying the Cu content up to 50 at. pct (Cu x NiCoZnAlTi; x = 0, 8.33, 33.33, 49.98 at. pct). The phase formation and stability of mechanically alloyed powder at an elevated temperature (1073 K [800 °C] for 1 hour) were studied. The nanocrystalline equiatomic Cu-Ni-Co-Zn-Al-Ti alloys have a face-centered cubic (fcc) structure up to quinary compositions and have a body-centered cubic (bcc) structure in a hexanary alloy. In nonequiatomic alloys, bcc is the dominating phase in the alloys containing 0 and 8.33 at. pct of Cu, and the fcc phase was observed in alloys with 33.33 and 49.98 at. pct of Cu. The Vicker's bulk hardness and compressive strength of the equiatomic nanocrystalline hexanary CuNiCoZnAlTi HEA after hot isostatic pressing is 8.79 GPa, and the compressive strength is 2.76 GPa. The hardness of these HEAs is higher than most commercial hard facing alloys (e.g., Stellite, which is 4.94 GPa)