654 research outputs found
Sort by
Investigation of Tool Life & Surface Roughness During Single Point Diamond Turning of Silicon.
No full textIn the present study investigation was done to analyze the tool life by analyzing the change in surface roughness with time during machining of silicon (infrared crystal) at optimized parameters with a single crystal
diamond tool. Silicon has low mass density, low cost & low coefficient of thermal expansion. Due to these properties it is used in microelectro, micro-mechanical & weight sensitive infrared applications where surface roughness is a major criteria for the acceptance of
the fabricated part. A contact type mechanical profilometer was used to measure the surface roughness of silicon
Double Pyrolysis of Chrome Tanned Leather Solid Waste for Safe Disposal and Products Recovery
No full textDisposal of chrome tanned leather waste (CTLW) generated in leather processing industries has many environmental implications. This paper presents a double pyrolysis (PI & PII) method to dispose hazardous chrome tanned leather solid waste by converting it into useful products. When CTLW was subjected to double pyrolysis, three major products obtained were; (i) an energy enriched combustible gas (32.01% - PI & 42.45% - PII ); (ii) a high fraction condensate (33.32% (PI & PII)) and (iii) a carbonaceous residual ash containing trivalent chromium (34.67%- PI & 24.23% -PII). In addi-tion, 2.73% of liquid fuel, 75.24% of nitrogen enriched liquid and 22.03% distillate tar as sub-products from the high fraction condensate. SEM, GC-MS, 1H & 13C NMR and TGA revealed that the products were free from toxic chromium species and contains both aliphatic and aromatic hydrocarbons. The residual ash displayed high thermal stability when run under nitrogen atmosphere (simulating 1st pyrolysis). The observations on generation of no toxic compounds upon double pyrolysis, suggests the suitability of this process towards achieving safe disposal of hazardous leather solid waste and to re-cover useful product
Zn Based Metal Organic Framework as Adsorbent Material for Mecoprop
No full textMetal organic framework, a new class of hybrid materials is now involved in a number of applications based on size and distribution pattern of its pores. Present research focus on Mecoprop adsorbent capacity of Basolite, a zinc based metal organic framework. Basolite (C8H12N4Zn) having a pore width 11.6Å and pore aperture 3.4Å has been used here for entrapping Mecoprop a commonly used pesticide which has very high mobility and a common contaminant for aquatic systems. Due to a very high surface area i.e 1300-1800 m2/gm of basolite and specific pore size it is found to be very efficient for adsorption purpose and another important property of Basolite is that it gets reactivated at 100oC so can be used again and again. Adsorption of pesticide by Basolite column was confirmed by UV Visible spectroscopy. The study revealed that Basolite adsorb Mecoprop due to entrapment of Mecoprop inside its pores. Basolite can be used for preparing filters on large scale for removing harmful pesticide from aquatic systems
Co-pyrolysis of Chrome Tanned Buffing Dust and Low Density Polyethylene Wastes and Analysis of Products for Energy Recovery
No full textChrome tanned buffing dust (CTBD) leather solid waste and low density polyethylene (LDPE) waste though it contains higher energy value are normally considered as most harmful and hazardous waste materials due to its non-biodegradability. In this paper CTBD and LDPE are pyrolysed separately and the pyrolysis results are compared with the results of co-pyrolysis of the mixed wastes in different
ratios (i.e. 1:1 and 1:2). The products i.e., residual ash, condensate liquid and combustible gas are characterized using i) Scanning Electron Microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and Gas Chromatography Mass Spectrometry (GCMS). It was observed that liquid condensate i) contains mostly carboxylic acid with strong smell of ammonia ii) alcohol, esters and iii) longer chain hydrocarbons. SEM analysis of co-pyrolysed residual ash and residual ash of LDPE shows the presence of nano carbon with the particle size in the range 70.9 nm – 129 nm. It was also observed that co-pyrolysis of CTBD with LDPE yielded energy enriched combustible gas having 5181kcal when mixed at a ratio of 1:2. The co-pyrolysis yielded reduction in carbon monoxide (CO) and increase in hydrogen (H2) as well as hydrocarbon (CxHy) gas conten
Non-parametric modified histogram equalisation for contrast enhancement
No full textHistogram equalisation has been a much sought-after technique for improving the contrast of an image, which however leads to an over enhancement of the image, giving it an unnatural and degraded appearance. In this framework, a generalised contrast enhancement algorithm is proposed which is independent of parameter setting for a given dynamic range of the input image. The algorithm uses the modified histogram for spatial transformation on grey scale to render a better quality image irrespective of the image type. Added to this, two variants of the proposed methodology are presented, one of which preserves the brightness of original image while the other variant increases the image brightness adaptively, giving it a better look. Qualitative and quantitative assessments like degree of entropy un-preservation, edge-based contrast measure and structure similarity index measures are then applied to the 500 image data set for comparing the proposed algorithm with several existing state-of-the-art algorithms. Experimental results show that the proposed algorithm produces better or comparable enhanced images than several algorithms
Analysis of Surface Roughness and Waviness During Diamond Turning of Polycarbonate
No full textPlastics are very common materials that can be diamond turned and widely used in optics and our ultra precise
applications. Surface texture parameters (Roughness and waviness) are very important considerations in these applications. In this experiment single point diamond turning is done on polycarbonate for about 200Kms length of machining. Surface roughness and waviness are plotted against machining time after certain no. of cycles. After machining 9Kms, surface roughness value was less than 15nms.With increase in machining time Ra values was increasing. Machining was stopped when roughness
value crossed 70nm .Waviness also increased with machining time. Waviness was below 1 µm up to 7 Kms. Further machining resulted in increased waviness .As polycarbonate is plastic, linear trend is seen in both roughness and waviness
Nanocomposite of Polyaniline with the photoadduct of potassium hexacyanoferrate and pyridine ligand: Structural, electrical, mechanical and thermal study
No full textThis work involves the synthesis of polyaniline nanocomposite with photoadduct of potassium hexacyanoferrate and pyridine achieved through ball milling, photochemical route, and by oxidative polymerization technique using ammonium persulphate as oxidizing agent .The photoadduct has been synthesized by photoirradiation followed by substitution with pyridine ligand. The photoaquation, substitution and successful synthesis has been proved by recording pH, UV–visible spectra, FTIR and XRD. The as synthesized nanocomposite has been subjected to various characterization techniques like elemental analysis, UV–visible spectra, FTIR, XRD, and SEM. XRD of photoadduct shows crystalline structure which has been retained in the nanocomposites also. Parameters like crystallite size, dislocation density, microstrain, d-spacing, were evaluated. Thermal study was carried out by recording TGA/DTG, showing very high thermal stability of nanocomposite as compared to PANI which can be due to strong interaction between polymer chain and photoadduct, hence the material can be used for high temperature applications electrical conductivity was measured by four probe conductivity meter. Conductivity of nanocomposite was found to be many orders of magnitude higher than that of polyaniline. The nanomechanical properties were investigated with an MTS Nano-Indenter XP by using continuous stiffness measurement (CSM) technique. Mechanical properties of pure PANI has improved with doping of photoadduct
A Technical Note on Monitoring of Jhakri Landslide in Bari Village Area of Himachal Pradesh
No full textThe occurrence of landslides is quite common on natural slopes and tectonically active region showing high degree of rock instability. A slope failure is developed due to
progressive external loads and deteriorations of slope geo-materials and is major cause of landslides. In our country, till date, some research institutes are carrying out scattered efforts to analyse the landslide hazards. Landslide analysis is too complex and needs systematic studies. CSIR-Central Scientific Instruments Organisation (CSIR-CSIO) is pursuing a research on instrumental monitoring of landslide and developing prediction algorithms. Under this research a part of Jhakri landslide in Bari village area of Himachal Pradesh (H.P.), an Indian State in the Himalayas, is instrumented in May 2012, and realtime data is being acquired round the clock. Installed instrumentation is modular and two-tier structured system. It is observed that monitoring network will be populated with more sensors and three-four years data will be acquired to develop and validate prediction algorithms
An experimental study on the effect of magneto-rheological finishing on diamond turned surfaces
No full textMagneto-rheological materials are a class of smart materials whose rheological properties can be rapidly varied by applying a magnetic field. Magneto-rheological finishing utilizes magneto-rheological fluid, which consists of magnetic particles, non-magnetic abrasives and some additives in water or other carrier to polish the materials. Single-point diamond turning
is able to remove hundreds of microns of material and generate surface with micron accuracies. Residual turning
marks are the most important factor limiting the performance in diamond turning process. Magneto-rheological finishing has inherent ability to improve micro-roughness, remove subsurface damage and reduce residual stresses induced during diamond turning process. Combining single-point diamond turning and magneto-rheological finishing creates a deterministic
process for manufacturing highly finished surfaces. In this article, an attempt has been made to improve the finish of diamond turned surface with magneto-rheological finishing and to investigate the effects of parameters like current, spacing, wheel speed, feed rate and magnetic field on the final surface finish. Based on the parametric study, an optimum combination of process parameters is identified using analysis of variance. Various image processing techniques have been used for the comparison of the surface analysis of diamond turned surfaces and the magneto-rheological finished surfaces