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Dewatering of alkali metal halide salts in conventional co-current or counter-current spray driers to obtain low moisture content and agglomeration in resultant dried powders is difficult owing to their hygroscopic nature. Co-current spray driers offer the advantage of good heat transport characteristics in spray zone while counter-current spray driers offer better thermal utilization throughout the drying chamber. In the present work, modified prototype of a conventional counter-current spray drier is developed to obtain both these advantages in the drying chamber by employing induction heating and mechanical pulsation techniques. After carrying out several experiments in this prototype viz. Induction heating-based pulsed spray drier (IH-PSD), the optimal process parameters are obtained which maximize thermal utilization throughout the drying chamber and minimize both moisture content and agglomeration in resultant dried powders of sodium and potassium halide salts. The initial droplet and final particle size distributions are obtained using laser diffraction analyzer and sieve shaker experiments respectively. An experimentally validated numerical model implemented using open-source computational solvers is utilized to obtain average drying rates in IH-PSD. It is observed that the average drying rate lies between 0.03 and 0.18 mg/s and 0.04 and 0.14 mg/s for sodium and potassium metal halide salts respectively. Spray drying prototype coupled with Induction heating and mechanical pulsation. Dewatering of sodium and potassium metal halide salts using the spray drying prototype. Numerical-neural network model implemented by open source computational solvers. Utilization of Laser diffraction analyser for measurement of initial droplet size. Model calculates the average drying rate with an accuracy around 83%. [ABSTRACT FROM AUTHOR]

Lithium orthosilicate (Li4SiO4) has the highest carbon dioxide (CO2) absorption capacity among the other lithium-based ceramic materials and is also suitable for high-temperature application for CO2 absorption. In this work, lithium orthosilicate pebbles of 1.0 mm size with 20% excess lithium carbonate were synthesized and fabricated by using Solid State Reaction Process (SSRP) and experiments were carried out to study the effect of various process parameters on its adsorption capacity of CO2 from air-CO2 mixture at elevated temperatures. The various process parameters studied were: operating gas flow rate, bed wall temperature and CO2 concentration in air on which very limited works have been reported. Effects of operating temperature, flow rate and inlet concentration of CO2 on absorption capacity have been studied to develop break through curves. The cyclic tests have been carried out with 15% CO2 concentration in air at 400°C and 200 LPH flowrate using the same material and carried out 135 consecutive absorption-desorption experimental runs. It was found that the CO2-absorption capacity of Li4SiO4 pebbles at 400°C and 200 LPH flowrates is about 31% for 30% carbon dioxide concentration in air and 22% for 15% carbon dioxide concentration in air. Moreover, no reduction in CO2-absorption capacity of the material was observed even after 135 consecutive absorption-desorption cycles. [ABSTRACT FROM AUTHOR]

Lithium orthosilicate has the highest absorption capacity among other materials used to capture carbon dioxide (CO2) at a higher temperature. To design a CO2 adsorption system consisting of lithium orthosilicate pebble bed, effective thermal conductivity and heat transfer coefficient data are necessary, and till date, these are not reported in the literature. In the present study, experiments were conducted to estimate the effective thermal conductivity and heat transfer coefficient of lithium orthosilicate pebble bed in CO2–air medium. Effects of CO2 concentration in air, bed temperature, and gas flowrate on the hydrodynamic as well as heat transfer properties of the pebble bed of lithium orthosilicate pebbles were also studied. The effective thermal conductivity and heat transfer coefficients were found in the range of 0.2–0.75 Wm−1K−1 and 14–63 Wm−2K−1, respectively. [ABSTRACT FROM AUTHOR]

In the present study, Reciprocating and Rotating Sieve Plate Column (RRSPC) was used with C6(mim)PF6; ionic liquid as dispersed phase and water as continuous phase to study hydrodynamics, which has not been studied till date. Experiments were conducted at different RPM, reciprocating pulsating frequency (RPF), dispersed phase velocity and total throughput, at different O/A ratios. It was found that disperse phase holdup increases with increase in dispersed phase velocity, total throughput (at different O/A ratios) and with increase in RPM/RPF. Simultaneous reciprocating pulsation and rotation produce good quality of dispersion of ionic liquid in range of 50 to 65 RPM/RPF. Phase inversion of dispersed phase to continuous phase takes place at 70 RPM/RPF when dispersed phase velocity ( V d ) exceeds 4.2 mm/s. Higher holdup was observed at lower RPM/RPF in RRSPC as compared to other type of column reported in literature. The optimum operating condition for RRSPC was found to be, 60–65 RPM/RPF to achieve better holdup and uniform quality of dispersion. It turned to emulsion phase above 70 RPM/RPF. Snapshots show flow visualization as well as dispersion quality. Regime maps of the system were presented to understand the mixing settler regime, dispersion and emulsion regime ranges. [ABSTRACT FROM AUTHOR]

This article proposes an area optimized design approach for two different analogue VLSI circuits: current mirror load based CMOS differential amplifier circuit and CMOS two-stage operational amplifier. The evolutionary method utilized for these optimal designs is the Seeker Optimization Algorithm (SOA). Human searching capability and understanding are modelled in SOA. In SOA, the search direction is based on the empirical gradient, and the step length is based on some simple fuzzy rule. In this article, SOA is employed to optimize the sizes of the MOS transistors to reduce the overall MOS area occupied by the circuit while satisfying the design constraints. The results obtained from the SOA technique are validated in SPICE environment. SPICE-based simulation results justify that SOA is a much better technique in comparison with the other formerly reported methods for the designs of the circuits mentioned above in terms of MOS area, gain, power dissipation, etc. [ABSTRACT FROM AUTHOR]

In this paper, the minimum fluidisation velocity ( u m f ) of activated carbon particles in a gas–solid fluidised bed was experimentally determined using dry air as the fluidising medium. The effect of particle size and temperature on the minimum fluidisation velocity of the fluidised activated carbon particles was analysed. The particle sizes 212, 425, and 710 µm and bed temperatures of 30°C, 100°C, 200°C, and 300°C were studied. From the experimental results, it was found that the u m f decreased with a decrease in particle size of the activated carbon particles and decreased with an increase in the temperature. Based on the experimental results, a new correlation was developed to predict u m f at higher temperatures, since at higher temperatures, the deviation of experimental u m f values was higher when compared with the values estimated using previously published correlations. The present study will be useful for the design of an experimental system to study the continuous adsorption and desorption of organic vapours at higher temperatures in the fluidised bed of activated carbon particles. The details of the experimental study and analysis of results are discussed in this paper. [ABSTRACT FROM AUTHOR]

To design passive air-cooled heat exchangers, an experimental study on natural convection in a square or rectangular duct was felt necessary, as literature on this subject is not available. In the present study, experiments were carried out using a square duct of size 500 × 500 × 800 mm height fabricated with 3.0 mm thick aluminium sheet and a brass cylinder of diameter 25 mm and height 200 mm was used as internal heat source. The heated duct was cooled by natural circulation of air. A 3D Computational Fluid Dynamics (CFD) model for natural convection with variable properties of air and no-slip condition was developed. Laminar simulations of cooling of a vertical cylinder in a rectangular duct was obtained by solving the governing equations using Fluent 6.2.16 along with Gambit v4.6.0 as pre-processor for grid generation. Grid generation resulted in 23,800 cells with 24,185 nodes. Segregated solver solution methodology has been used for simulation with implicit linearization of the Equations (10–14). Finite volume or control volume discretization technique has been used with iterative solution techniques. Residual of the order offor momentum equation, laminar model andfor energy equation was used for convergence and stability check. The solver used was based on SIMPLE algorithm. Variation of density and viscosity of air with temperature were accounted for in the simulation. The model was validated by using experimental data. Average heat transfer coefficients were estimated. It was found that the theoretically calculated average heat transfer coefficients were in good agreement with the modelled values. [ABSTRACT FROM PUBLISHER]

Lithium-doped dysprosium oxide (LiDyO2) is a potential material for high-temperature applications of solid-state batteries. Experiments were conducted to synthesize LiDyO2by the solid-state reaction of lithium carbonate (Li2CO3) and dysprosium oxide (Dy2O3). The XRD pattern of the synthesized powder confirmed the formation of single-phase LiDyO2. From the TG-DTA study it was observed that the decomposition of Li2CO3starts at 740.9°C and the reaction between Li2CO3and Dy2O3starts at 750°C. The XRD analysis confirmed that mass loss observed in the TG-DTA study for the mixture of Li2CO3and Dy2O3at 750°C is due to the formation of LiDyO2. From the kinetic study it was found that the reaction of Li2CO3and Dy2O3follows nucleation mechanism. It was found that the best fitted model for reaction is the power law P4 nucleation model. Ozawa–Flynn–Wall method is the best suited method for fitting of the solid-state reaction model for reaction of Li2CO3and Dy2O3. The activation energy and pre-exponential factor for reaction of Li2CO3and Dy2O3were determined as 561–631 kJ/mol and 15.34–26.90 min−1, respectively. [ABSTRACT FROM PUBLISHER]

The fusion of deuterium and tritium is being considered for the energy source from fusion reactions, and on reaction each nuclei will produce one helium nuclei, one neutron and thermal energy. Deuterium is naturally available and the technologies to separate it from the compounds of hydrogen are well developed. Tritium can be produced by nuclear reaction of Li6isotope with thermal neutrons, and natural lithium contains about 7.5% Li6. Lithium has a low melting point and readily reacts with oxygen, nitrogen and moisture present in air. So, lithium-containing ceramics, namely lithium orthosilicate and lithium titanate enriched in Li6isotope, are being considered for tritium production by nuclear reaction with neutron. It was found that like lithium titanate, lithium orthosilicate can also be synthesised and pebbles can be fabricated by solid-state reaction process by using silica and lithium carbonate as raw materials. The advantage of this process is that the synthesis can be carried out at 800°C and fabricated pebbles can be sintered at 900°C to achieve the desired properties of the pebbles. Both these temperatures for synthesis and sintering are lower than that of the molten spray method. The experimental details and results are discussed in this paper. [ABSTRACT FROM PUBLISHER]

Lithium titanate (Li2TiO3) and lithium orthosilicate (Li4SiO4) are the promising solid breeder materials for the fusion reactors. Packed bed of Li2TiO3or Li4SiO4pebbles is considered in the fusion reactor blanket for in situ production of tritium and for this a good effective thermal conductivity of the pebble bed is necessary. In recent past, Mandalet al.[26] studied the hydrodynamics and heat transfer properties of bed of lithium titanate pebbles at different operating conditions viz., gas flow rates, pebble sizes, bed wall temperatures, etc. In the present study laminar,k – εand low Reynoldsk – εmodel have been used to simulate the hydrodynamics and heat transfer data of Li2TiO3pebble bed. The computational fluid dynamics (CFD)-simulated hydrodynamics results have been compared with hydrodynamics and heat transfer results of bed of Li2TiO3pebbles reported by Mandal et al. [26] and others. It was found thatk – εand low Reynolds numberk – εmodel shows better agreement with experimental results. The CFD study were carried out using low Reynoldsk – εmodel for pebble bed of different materials viz. Li2TiO3, Li4SiO4and alumina (Al2O3). The effect of flow rate, pebble size, wall temperature, solid properties viz. thermal conductivity and specific heat on effective thermal conductivity and overall heat transfer coefficient has been discussed in this paper. [ABSTRACT FROM AUTHOR]

This paper proposes a novel hybrid optimisation algorithm which combines the recently proposed evolutionary algorithm Backtracking Search Algorithm (BSA) with another widely accepted evolutionary algorithm, namely, Differential Evolution (DE). The proposed algorithm called BSA-DE is employed for the optimal designs of two commonly used analogue circuits, namely Complementary Metal Oxide Semiconductor (CMOS) differential amplifier circuit with current mirror load and CMOS two-stage operational amplifier (op-amp) circuit. BSA has a simple structure that is effective, fast and capable of solving multimodal problems. DE is a stochastic, population-based heuristic approach, having the capability to solve global optimisation problems. In this paper, the transistors’ sizes are optimised using the proposed BSA-DE to minimise the areas occupied by the circuits and to improve the performances of the circuits. The simulation results justify the superiority of BSA-DE in global convergence properties and fine tuning ability, and prove it to be a promising candidate for the optimal design of the analogue CMOS amplifier circuits. The simulation results obtained for both the amplifier circuits prove the effectiveness of the proposed BSA-DE-based approach over DE, harmony search (HS), artificial bee colony (ABC) and PSO in terms of convergence speed, design specifications and design parameters of the optimal design of the analogue CMOS amplifier circuits. It is shown that BSA-DE-based design technique for each amplifier circuit yields the least MOS transistor area, and each designed circuit is shown to have the best performance parameters such as gain, power dissipation, etc., as compared with those of other recently reported literature. [ABSTRACT FROM AUTHOR]

Dispersion of Rayleigh-type surface waves is studied in a sandy layer under a uniform layer of homogeneous liquid lying over liquid-saturated porous solid half-space. The frequency equation in the form of a ninth-order determinant is obtained and evaluated. Special cases have been deduced and dispersion curves for the phase velocity and wave number have been plotted for a particular model. [ABSTRACT FROM AUTHOR]

The plane wave propagation in an inhomogeneous anisotropic thermally conducting elastic solid is studied with two thermal relaxation times. Three types of plane waves—quasi-P, quasi-S, and thermal waves—are shown to exist. The analytical expressions for their velocities of propagation are obtained. The inhomogeneity drastically affects the velocity of these waves and also depends on the angle of propagation and frequency. The effects of these parameters are shown graphically. [ABSTRACT FROM PUBLISHER]

Batch adsorption experiments were carried out to remove color from aqueous medium using a novel bioadsorbent prepared from bamboo leaves. Methylene blue (MB) dye was chosen as the source of color and it was adsorbed on bamboo leaves powder (BLP) and surfactant modified BLP using Triton X-100 (TX-100) and Sodium dodecyl sulfate (SDS), separately. The effects of various process parameters, viz. contact time, adsorbent dose, pH, temperature, and stirring speed were investigated in detail. Adsorption efficiencies of all the three adsorbents were compared and analyzed. The performance of SDS modified BLP was found to be excellent. Thermodynamic parameters and reaction kinetics were studied to know the nature and mechanism of adsorption. The results showed that MB adsorption followed pseudo second order kinetics and was endothermic in nature. The adsorption equilibrium was also investigated with the Langmuir, Freundlich, and Temkin isotherm models. The Langmuir isotherm was fitted well with a maximum dye uptake capacity of 125, 143, and 200 mg/g for BLP, BLP modified with TX-100, and SDS, respectively. A regeneration technique was proposed in order to reuse the adsorbent for better economy of the process. Finally, a process calculation was reported to know the amount of adsorbent required for efficient removal of MB. [ABSTRACT FROM PUBLISHER]

This article develops an efficient and reliable evolutionary programming algorithm, namely quasi-oppositional biogeography-based optimization, for solving optimal power flow problems. To improve the simulation results as well as the speed of convergence, opposition-based learning is incorporated in the original biogeography-based optimization algorithm. In order to investigate the performance, the proposed scheme is applied on optimal power flow problems of standard 26-bus, IEEE 118-bus, and IEEE 300-bus systems; and comparisons among mixed-integer particle swarm optimization, evolutionary programming, the genetic algorithm, original biogeography-based optimization, and quasi-oppositional biogeography-based optimization are presented. The results show that the new quasi-oppositional biogeography-based optimization algorithm outperforms the other techniques in terms of convergence speed and global search ability. [ABSTRACT FROM PUBLISHER]

Soil loss tolerance limit (SLTL) is the maximum amount of soil which can be removed annually before the long-term soil productivity is adversely affected. In many situations, the establishment of a SLTL is intended to provide basic information for the maintenance of soil productivity, which becomes one of the foci of the sustainability of agricultural land use. In India a default soil loss tolerance limit of 11.2 Mg ha-1 yr -1 is followed for planning soil conservation activities. The objective of this study is to provide a methodology to estimate quantitative SLTLs for suggesting suitable soil conservation measures. The assessment framework used follows three basic steps; viz. indicator selection, indicator interpretation and integration into a soil quality (SQ) index value. A quantitative model was used to integrate potential soil indicators such as saturated hydraulic conductivity, bulk density, soil erodibility, organic carbon and pH to assess soil resistibility to erosion. Scaling functions were used to convert soil parameters to a unitless 0 to 1 scale. Normalized values of all these soil parameters were then multiplied by assigned weights based on relative importance and sensitivity analysis. Soils were grouped into 1, 2, and 3 depending on overall additive score. A general guideline developed by the USDA-Natural Resource Conservation Service (NRCS) was followed, with certain modifications in depth categories, for estimation of SLTLs. The model was tested on 14.86 Mha of land in northern India comprising of the states of Punjab, Haryana and Himachal Pradesh. SLTLs varied from 2.5 to 12.5 Mg ha-1 yr -1 compared to the single value applied earlier. [ABSTRACT FROM AUTHOR]

Several lines of evidence support that impairment of host immune function by tumor may be related to several strategies of tumor escape from immunosurveillance. We found that in Ehrlich's ascites carcinoma (EAC)-bearing mice, the tumor cells secrete immunosuppressive cytokines, transforming growth factor beta (TGF-beta) and interleukin-10 (IL-10) that induce a general T helper cells type 2 (Th2) dominance dampening the T cytotoxic cells type 1 (Tc1) population. Interestingly, black tea at the antitumor dose of 2.5% significantly reduced TGF-beta and IL-10 in tumor cells in vivo, thereby preventing Th2 dominance in the tumor bearers and initiating a Th1/Tc1 response. Thus, apart from its anticancer activity, this popular beverage also rejuvenates cancer immunosurveillance by modulating cytokine profiles and establishing Th1/Tc1 dominance in the tumor-bearing host. [ABSTRACT FROM AUTHOR]

A method for the extraction of gallium(III) with LIX 26 in n-decanol as a moderator has been studied. The extraction of gallium(III) was found to be quantitative with 10 vol% LIX 26 (alkyl substituted 8-hydroxyquinoline) as extractant, 10 vol% n-decanol as modifier and kerosene as diluent. At 1:1 organic to aqueous phase ratio at 30°C, 99% of gallium was recovered in 30 min. The effect of various parameters such as LIX 26 concentration, n-decanol concentration, time to achieve equilibrium, variation of pH, and temperature on the extraction of gallium(III) were also studied. The stoichiometry of the extracted species of gallium(III) was determined. The extraction of gallium(III) proceeds through a cation exchange mechanism and the extracted species is in the GaL3 form. The equilibrium constant and thermodynamic functions Enthalpy (ΔH), Entropy (ΔS), and Free Energy (ΔG) in the extraction of gallium(III) with LIX 26 have been evaluated. The extraction reaction was an exothermic process. [ABSTRACT FROM AUTHOR]

Abstract\nHIGHLIGHTSHygroscopic nature of alkali metal chloride salts makes attaining mono-sized dried particles from their aqueous precursor solution an engineering challenge for conventional co-current or counter-current spray driers. Conventional spray driers offer better thermal utilization in either the spray zone or dried particle zone depending on their configuration viz. co-current or counter-current, respectively. In this work, an alternative prototype named induction heating based pulsed spray drier (IH-PSD) is proposed to obtain dry alkali metal chloride salt powders with narrow particle size distribution. Laser diffraction analysis is carried out for initial droplet size distribution whereas scanning electron microscopy and sieve shaker analysis is carried out for studying the particle morphology and particle size distribution of dried powder for all the selected salts. The resultant particle properties emphasized in the present work are the dried particle to initial droplet diameter ratio and the wet basis moisture content. It has been observed that the ratio of mean volume diameter of dried particle to sauter mean diameter of initial droplet lies in the range of 0.4–3.6 meanwhile the wet basis moisture content of dried powder lies in the range of 1.4–3.6 for the selected salts. Artificial neural network (ANN) model is applied for inferring the influence of IHPSD process parameters on the above mentioned dried particle properties and satisfactory convergence with experimental values has been achieved.Spray drying prototype coupled with Induction heating and mechanical pulsationScanning electron microscopy for morphological study of spray dried particleLaser diffraction for initial droplet size distribution analysisSieve shaker experiments for size distribution analysis of spray dried particleArtificial neural network for prediction of droplet to dried particle size ratio [ABSTRACT FROM AUTHOR]

Comments on a study that discussed the association of the levels of the DNA adduct and N7-methyldeoxyguanosine with increased risk of failure of treatment of cervical intraepithelial neoplasia (CIN). Flaws of the study; Contribution of the exposure of the cervix to oncogenic subtypes of pappilomaviruses to the development of CIN; Failure of the researchers to analyze the impact of cigarette smoking on CIN treatment.