Scope and opportunities of using glycerol as an energy source

Biodiesel is a promising fuel for diesel engines in wake of its renewable nature and environmental benefits. Biodiesel can be produced by different pathways; however, glycerol (or glycerin, glycerin) is a valuable by-product which is formed during this process. As mandates are being enforced by different government worlds over, the demand of biodiesel is likely to go up. With increased demand and production of biodiesel, significant quantity of glycerol shall be available. There is an urgent need to find alternative application area of glycerol so that viability of biodiesel industry can be sustained.In the present study, the focus has been made on the various application areas of using surplus glycerol from biodiesel industries to make them more financially attractive. Amongst the different pathways of using glycerol as a source of energy; direct combustion, mixing with agricultural solid wastes and then burning, blending directly or indirectly with other fuels, hydrogen and hydrocarbon production from glycerol, etherification, etc. are prominent one. The requirement, advantages and limitations of each approach have also been evaluated in the study. Combustion of glycerol if not done properly would result in formation of acrolien which is highly toxic in nature and efforts should be made to use glycerol indirectly to produce energy (i.e. all the pathways expect the direct combustion and the solid fuel method). The production of hydrogen from glycerol via APR appears to be the best solution to the disposal problem since the hydrogen yield via APR is highest. Moreover the process occurs at lower pressure and temperature when compared to steam reforming, and it is a single step process. Etherification, tri-acetylisation, and blending have been found to be useful for improving the performance of automotives by facilitating proper and smooth combustion of fuel.     

Uncertainty analysis of LBLOCA for Advanced Heavy Water Reactor

The main objective of safety analysis is to demonstrate in a robust way that all safety requirements are met, i.e. sufficient margins exist between real values of important parameters and their threshold values at which damage of the barriers against release of radioactivity would occur. As stated in the IAEA Safety Requirements for Design of NPPs “a safety analysis of the plant design shall be conducted in which methods of both deterministic and probabilistic analysis shall be applied”. It is required that “the computer programs, analytical methods and plant models used in the safety analysis shall be verified and validated, and adequate consideration shall be given to uncertainties”. Uncertainties are present in calculations due to the computer codes, initial and boundary conditions, plant state, fuel parameters, scaling and numerical solution algorithm.     

Effect of Iron Ore Pellet Size on its Properties and Microstructure

The properties of the pellets and their microstructure mainly depend on the raw material mix proportion, raw material chemical composition and the physicochemical conditions like the temperature and oxygen partial pressure within the induration machine. The pelletising plant products are in the size range of 8 to 16 mm. With increasing pellet size, the sintering intensity, thermo‐chemical conditions and formation of different phases vary across its cross section. The time required for varies reactions within the pellet is directly proportional to the pellet size. Because of differences in pellet size, the reduction and oxidation process takes place under different conditions resulting in different phases and microstructures. In this work, detailed studies were carried out on pellets of different size (8 to 16 mm) produced from a 4.2 Mtpa pellet plant for their physical, metallurgical and microstructural properties. It was observed that the pellets in the size range of +8 to ‐12 mm showed good strength and lower RDI. It was observed that the amount of hematite, magnetite, porosity, pore density, pore size and slag phase play a significant role on pellet strength and RDI.     

Measuring external profiles of porous objects using CMM

Coordinate measuring machine (CMM) has been extensively used in surface measurement and inspection. CMM produces more accurate and reliable results compared with non-contact measurement devices, since CMM measures target surfaces in a tactile way and is not affected by surface reflection quality. However, when there is porosity on the outside surfaces, CMM measurement will have errors because part of the probing stylus will come into the porosity spaces. This paper presents a method of using CMM to measure external profiles of objects with external porosity spaces. The center of a CMM probing stylus will be compensated to avoid porosity spaces and located above external surface areas along surface normal directions. Such a probing strategy can be implemented in both computer-aided design (CAD)-guided mode and non-CAD-guided mode. When the CAD model is available, the probing styli are guided to approach the surface along its normal directions successively to identify and avoid porosity spaces. When the CAD model is unavailable, surface normal directions will be estimated first and then adjusted. The presented method is able to avoid porosity spaces in CMM measurement regardless of the availability of CAD models.     

Eco-friendly (green) synthesis of magnetically active gold nanoclusters

Abstract

Au–Fe_xO_y composite nanoparticles (NPs) are of great technological interest due to their combined optical and magnetic properties. However, typical syntheses are neither simple nor ecologically friendly, creating a challenging situation for process scale-up. Here we describe conditions for preparing Au–Fe_xO_y NPs in aqueous solutions and at ambient temperatures, without resorting to solvents or amphiphilic surfactants with poor sustainability profiles. These magnetic gold nanoclusters (MGNCs) are prepared in practical yields with average sizes slightly below 100 nm, and surface plasmon resonances that extend to near-infrared wavelengths, and sufficient magnetic moment (up to 6 emu g^–1) to permit collection within minutes by handheld magnets. The MGNCs also produce significant photoluminescence when excited at 488 nm. Energy dispersive X-ray (EDX) analysis indicates a relatively even distribution of Fe within the MGNCs, as opposed to a central magnetic core.     

A series of novel double perovskite oxides NaMTi<Subscript>2</Subscript>O<Subscript>6</Subscript> (M = Eu,Sm, and Gd): preparation,characterization and photocatalytic studies under visible and solarlight irradiation

The photocatalytic activity of sol–gel synthesized double perovskite type oxides NaEuTi₂O₆(NETO), NaSmTi₂O₆ (NSTO), and NaGdTi₂O₆ (NGTO) powders on degradation of methylene blue (MB) dye was demonstrated for the first time under visible light as well as sunlight irradiation. The obtained samples were characterized by X-ray diffraction, UV–Visible diffuse reflectance spectroscopy and scanning electron microscopy equipped with X-ray energy-dispersion spectrometry. All the three samples have shown photocatalytic activity for degradation of MB under sunlight and visible light irradiation and their photocatalytic activity followed the order of NGTO > NETO > NSTO. The superior activity of NGTO is ascribed to the higher amount of hydroxyl radicals generated in the photocatalytic reaction.     

Magnetometry of Individual Polycrystalline Ferromagnetic Nanowires

Ferromagnetic nanowires are finding use as untethered sensors and actuators for probing micro‐ and nanoscale biophysical phenomena, such as for localized sensing and application of forces and torques on biological samples, for tissue heating through magnetic hyperthermia, and for microrheology. Quantifying the magnetic properties of individual isolated nanowires is crucial for such applications. Dynamic cantilever magnetometry is used to measure the magnetic properties of individual sub‐500 nm diameter polycrystalline nanowires of Ni and Ni₈₀Co₂₀ fabricated by template‐assisted electrochemical deposition. The values are compared with bulk, ensemble measurements when the nanowires are still embedded within their growth matrix. It is found that single‐particle and ensemble measurements of nanowires yield significantly different results that reflect inter‐nanowire interactions and chemical modifications of the sample during the release process from the growth matrix. The results highlight the importance of performing single‐particle characterization for objects that will be used as individual magnetic nanoactuators or nanosensors in biomedical applications.     

Life Cycle Assessment of Wire Rope Used in Crane Application in a Steel Plant

Journal of Failure Analysis and Prevention - Wire rope is an important part of any crane. Failure of wire rope may lead to major loss in terms of life and cost. Wire rope failures are attributed by...