Novel critical point drying (CPD) based preparation and transmission electron microscopy (TEM) imaging of protein specific molecularly imprinted polymers (HydroMIPs)

We report the transmission electron microscopy (TEM) imaging of a hydrogel based molecularly imprinted polymer (HydroMIP) specific to the template molecule bovine haemoglobin (BHb). A novel critical point drying based sample preparation technique was employed to prepare the molecularly imprinted polymer (MIP) samples in a manner that would facilitate the use of TEM to image the imprinted cavities, and provide an appropriate degree of both magnification and resolution to image polymer architecture in the <10 nm range. For the first time, polymer structure has been detailed that tentatively suggests molecularly imprinted cavities, ranging from 5 to 50 nm in size, that correlate (in terms of size) with the protein molecule employed as the imprinting template. The modified critical point drying sample preparation technique used may potentially play a key role in the imaging of all molecularly imprinted polymers, particularly those prepared in the aqueous phase.     

High field electrical behaviour in lithium-phospho-vanadate glass system

The high field electrical switching behaviour of lithium-phospho-vanadate glasses has been studied by determining the current-voltage characteristics. The investigated glasses exhibit temperature, thickness and composition dependent trends. At low current, the I–V characteristics obey Ohm’s law followed by a negative resistance region where the bulk behaviour dominates and at higher values of current the sample goes to a low resistance state. The studied glasses exhibit memory type switching. It is suggested that electrical switching is due to the formation of conducting channels that are due to electronic origin while thermal effects dominate once the channels are formed resulting in crystallization.     

Utility-Interactive Hybrid Distributed Generation Scheme With Compensation Feature

A new, utility-interactive hybrid distributed generation scheme, with reactive power compensation feature, is presented. The basic objective is to realize a reliable power supply for a remotely located critical load. Fuel cell (FC) stack and photovoltaic (PV) array are considered as energy sources. These sources can be operated independently or in conjunction as per the requirement. The control logic employed ensures maximum utilization of the PV array, resulting in optimum operational costs. Only one inverter is used to connect both the FC stack and the PV array to the utility. Apart from feeding active power into the grid, the system can also provide reactive power compensation. Active and reactive power can be independently controlled by controlling the inverter's power angle and modulation index, respectively. This provides more flexibility in control and operation. All the details of this work, including power and control circuits, MATLAB simulation results, and experimental results, are presented.     

Modelling of low-latitude ionosphere using modified planar fit method for GAGAN

Several countries have been developing satellite-based augmentation systems (SBAS) for improving positional accuracy of global positioning system (GPS). India is also developing one such system popularly known as GPS aided geo augmented navigation (GAGAN) system. Modelling of ionospheric effects is one of the major challenges in developing precise and reliable GAGAN. The high values of total electron content (TEC), the large diurnal and seasonal variability and intense irregularities present in the low-latitude ionosphere, lead to unacceptable positional errors in GAGAN service region. Todd Walter et al. of Stanford University, USA have made significant contribution in the area of SBAS ionospheric grid modelling by developing the popularly known planar fit model. It is reported by Walter et al. (2000) that a constant decorrelation value of 35 cm was proposed over the wide area augmentation system (WAAS) service region. To provide accurate estimation of ionospheric delays at user ionospheric pierce points (IPP) during a storm or intense irregularities, an irregularity detector and a decorrelation adaptor are incorporated in the modelling. As planar fit model is not adequate to model intense irregularities of Indian ionosphere, a modified planar fit model is applied for GAGAN data on similar lines as was done for WAAS and the results are encouraging.     

An Efficient Protocol for Aza-Michael Addition Reactions Under Solvent-Free Condition Employing Sulfated Zirconia Catalyst

The aza-Michael addition reactions of amines with α,β-unsaturated carbonyl compounds were efficiently carried out at room temperature under solvent-free condition employing sulfated zirconia as a reusable heterogeneous catalyst. The desired products were formed in short reaction times and in high yields. The bulk and surface properties of the synthesized catalyst was examined by X-ray powder diffraction, BET surface area, temperature programmed desorption of ammonia, scanning electron microscopy and thermogravimetric techniques. Characterization results reveal the super acidic nature of the catalyst.     

Beneficiation Studies on Recovery of Secondary Sources of Iron from Ferrigenous Alluvial Sands

Beneficiation studies were carried out on iron bearing alluvial sand to recover iron values for pelletisation. The studies include detailed mineralogical characterization, physical and chemical characteristics, beneficiation studies including grinding, magnetic and high tension separation. The results of these investigations indicate that the samples contain 50.2% Fe and 8.2% SiO₂ on average. The mineralogical studies reveal that the sand contains dominantly heavy minerals with small amount of quartz. The heavy minerals are magnetite and ilmenite with small quantities of amphibole and pyroxene group minerals. Detailed beneficiation studies carried out by various techniques indicated that the iron content can be upgraded by simple low intensity wet magnetic separation after grinding the sample to below 210 microns. A product with 62.7% Fe can be obtained at 65.5% yield. The product obtained can be used for pelletisation by blending with suitable high grade iron concentrate.     

6BTA 5.9 G2-1 Cummins engine performance and emission tests using methyl ester mahua (Madhuca indica) oil/diesel blends

Neat mahua oil poses some problems when subjected to prolonged usage in CI engine. The transesterification of mahua oil can reduce these problems. The use of biodiesel fuel as substitute for conventional petroleum fuel in heavy-duty diesel engine is receiving an increasing amount of attention. This interest is based on the properties of bio-diesel including the fact that it is produced from a renewable resource, its biodegradability and potential to exhaust emissions. A Cummins 6BTA 5.9 G2- 1, 158 HP rated power, turbocharged, DI, water cooled diesel engine was run on diesel, methyl ester of mahua oil and its blends at constant speed of 1500 rpm under variable load conditions. The volumetric blending ratios of biodiesel with conventional diesel fuel were set at 0, 20, 40, 60, and 100. Engine performance (brake specific fuel consumption, brake specific energy consumption, thermal efficiency and exhaust gas temperature) and emissions (CO, HC and NOx) were measured to evaluate and compute the behavior of the diesel engine running on biodiesel. The results indicate that with the increase of biodiesel in the blends CO, HC reduces significantly, fuel consumption and NOx emission of biodiesel increases slightly compared with diesel. Brake specific energy consumption decreases and thermal efficiency of engine slightly increases when operating on 20% biodiesel than that operating on diesel.     

Radiation and mass transfer effects on two-dimensional flow past an impulsively started infinite vertical plate

The interaction of free convection with thermal radiation of a viscous incompressible unsteady flow past an impulsively started vertical plate with heat and mass transfer is analyzed. The fluid is gray, absorbing-emitting but non-scattering medium and the Rosseland approximation is used to describe the radiative flux in the energy equation. The dimensionless governing equations are solved using an implicit finite-difference method of Crank–Nicolson type. Numerical results for the velocity, the temperature, the concentration, the local and average skin-friction, the Nusselt number and Sherwood number are shown graphically. It is observed that, when the radiation parameter increases, the velocity and temperature decrease in the boundary layer. The local and average skin-friction increases with the increase in radiation parameter. For increasing values of radiation parameter the local as well as average Nusselt number increases.     

Advanced traveler information system for Hyderabad City

The advanced traveler information system (ATIS) is a type of intelligent transportation system application areas that implements emerging computer, communication, and information technologies to provide vital information to the users of a system regarding traffic regulation, route and location guidance, hazardous situations and safety advisory, and warning messages. ATIS requires a large amount of data for processing, analysis, and storage for effective dissemination of traveler information to users. A geographical information system (GIS) allows large data to be effectively processed, stored, analyzed, logically associated, and graphical displayed. Thus, GIS-based ATIS provides a convenient and powerful tool for storage and graphical representation of information, which can be useful users. Further, by availing the powerful GIS functionalities, a user can conceive a problem and allow the appropriate software to assist him in the decision-making process regarding optimum route selection and trip planning. In this paper, the authors present a GIS-based ATIS for Hyderabad City, India. Development of this GIS-based ATIS has been carried under the ArcView GIS environment. This user-friendly system provides comprehensive information about Hyderabad City, such as road networks, hospitals, government and private offices, stadiums, bus and railway stations, and tourist places within the city limits. This system can be used effectively in bus stations, railway stations, airports, and tourist information centers, as well as in personal computers to provide information to travelers and to facilitate travel.