IMPROVEMENTS IN GAS INDUCING IMPELLER DESIGN

Rate of gas induction, static pressure, mixing time and power consumption have been measured in 0.57 m i.d. vessel. Different types of impellers namely shrouded disc turbine, shrouded curved blade turbine and pitched blade turbine were used. The impeller diameter was varied from 0.15-0.25 m and the impeller speed was varied from 3 to 20 r/s.

The pitched blade turbine was found to give 30-60 per cent higher rates of gas induction as compared with the best design reported in the literature. The mixing time was found to be lower by a similar magnitude. Moreover in the case of pitched blade turbine it was found that the gas was getting induced radially as well as axially. This eliminates the necessity of the diffuser and hence reducing the complexities in the mechanical structure.     

CO2 process intensification of algae oil extraction to biodiesel

Algae-to-biodiesel processes are hindered by high costs and low energy return on investment.^1,2. Herein, three foci in research improve algae-to-biodiesel processes by: (1) reducing high installation and energy costs in the CO₂ sequestration, cultivation, and harvesting stages; (2) improving oil extraction and biodiesel generation; and (3) increasing utilization of the proteins in lipid-extracted biomass (e.g., for animal feed), as well as the omega-3 fatty acids for nutraceuticals and food supplements. A process is introduced that uses carbon dioxide to aid in all three of these foci. CO₂ is used first in the form of microbubbles to lyse algae cell walls, releasing triglyceride oils. CO₂ also aids with transesterification of these triglycerides using methanol. At low temperatures (353.15–368.15 K) and intermediate pressures (5–10 MMPa), carbon dioxide causes methanol to dissolve partially in the triglyceride phase and triglyceride to dissolve partially in the methanol phase, increasing the transesterification reaction rate. Due to the nondestructive nature of these processes, other metabolites can also be harvested providing improvements in both mass and economic efficiency with an overall sharp reduction in the modeled price of biodiesel.     

HiveSec: security in resource-constrained wireless networks inspired by beehives and bee swarms

Cryptographic algorithms rely on the strengths of all their fundamental components and expect them to be harmonious in accomplishing desired levels of security in applications. In order for a security solution to be sophisticated and to provide high security (measured in terms of the security goals it satisfies), the solution needs to typically involve complex mathematical operations and/or multiple stages of operation. While these might offer increased security, such solutions might not be applicable to all systems. We refer to resource-constrained wireless networks, such as radio frequency identification and wireless body area networks, where the resources available on-chip are often decided by the balance between device costs, requirements of longevity and usability. The constraints, thus, require designing solutions that use simple logical operations and are based on reuse of functions, while introducing sufficient unpredictability to increase security. In this paper, we present a key management and message signature generation scheme called HiveSec, whose design is inspired by the symmetry in beehives and the nature of bee swarms, and which offers security through unpredictability and reduced resource usage. We validate our work through simulation studies and security analysis.     

Probabilistic Belief Contraction

Probabilistic belief contraction has been a much neglected topic in the field of probabilistic reasoning. This is due to the difficulty in establishing a reasonable reversal of the effect of Bayesian conditionalization on a probabilistic distribution. We show that indifferent contraction, a solution proposed by Ramer to this problem through a judicious use of the principle of maximum entropy, is a probabilistic version of a full meet contraction. We then propose variations of indifferent contraction, using both the Shannon entropy measure as well as the Hartley entropy measure, with an aim to avoid excessive loss of beliefs that full meet contraction entails.     

An enhanced security mechanism through blockchain for E-polling/counting process using IoT devices

Wireless Networks - One of the biggest challenges in political mayhem is visible during the election process where no stone is kept unturned in order to gain the power. Further, due to poll...     

Consumer Attention to an Over‐the‐counter Warning in Four Different Styles of Design

The study consisted of three objectives: (a) to test the relative prominence and conspicuousness of a warning required by US law to be conspicuous; (b) to explore whether or not the conspicuousness of the said warning can be enhanced graphically; and (c) to develop preliminary data for power analysis that would guide decisions related to sample size in future studies. Seventeen subjects viewed four over‐the‐counter drug packages (each with a different style of warning) along with five other products while wearing an eye tracking device. Four styles of warning were used on the over‐the‐counter drug packages: no outline and no fill, outline and no fill, no outline and fill, and outline and fill. The surface area and the placement of the warnings were held constant across all four designs and were consistent with those on commercially available products. Collected data were broken into five zones: warning, brand name, strength, product benefit and net weight. Despite the fact that US law requires it to be conspicuous, the tested warning was significantly less noticeable than the brand name (objective one) for all dependent variables analyzed (α = 0.05). No significant difference was indicated for the varied warning designs (objective two). This could be because not much can be done to enhance prominence when constrained to the limited space that is typically used for such warnings or because of the limited sample size. Power calculations suggest that a sample size of nearly 200 subjects would be required to detect a 2.5 s mean difference at 80% confidence (objective three). Copyright © 2011 John Wiley & Sons, Ltd.     

Reactive power pricing structure for hydroelectric power station in condenser mode operation

Reactive power support is critical for system security and pricing of reactive power is a vital issue in restructured environment. Peaking units at hydroelectric power plant in condenser mode operation can provide major reactive power support. Therefore costing structure for hydroelectric power plant incorporating various cost components in condenser mode operation is presented in this paper. Major cost components include capital cost component, changeover cost component and a cost component related to number of service hours in condenser mode operation. A methodology is proposed based on these components. A case study of Koyna Hydro Electric Power Plant (KHEPP) is elaborated.     

Single-crystal relaxor ferroelectric piezoactuators with interdigitated electrodes

We report on the fabrication and performance of (1-x) Pb(Zn(1/3)Nb(2/3))O3-xPbTiO3 (PZN-PT) single-crystal relaxor piezoactuators with interdigitated electrodes patterned on a single surface. An electric field gradient across the sample thickness induces a differential contraction between opposite faces, and it is responsible for the actuation. The samples are poled by energizing the electrodes at 100 degrees C and cooling in a field. Calculations of the piezoelectric response based on a periodically modulated dipolar field yield good agreement with experiment. Discrepancies with the model are ascribed to multidomain formation in the ferroelectric sample as a result of field reversals in the applied electric field along the sample length.