Influence of Variable Thermophysical Properties on Nanofluid Bioconvection along a Vertical Isothermal Cone

The prime purpose of this analysis is to investigate the effect of variable thermophysical properties of nano fluid on bioconvection boundary layer flow past a uniformly heated vertical cone. The governing equations with associated boundary conditions for this phenomenon are cast into a non-dimensional form via continuous transformation, which are then solved by using the implicit finite difference method. How does the phenomena of heat transfer is effected due to the temperature-dependent thermophysical properties of the fluid is the question investigated in this manuscript. Comprehensive numerical computations are carried out for wide range of the parameters that are describing the flow characteristics. The influence of the governing physical parameters on the distribution of velocity and temperature profiles, wall skin friction and local rate of heat transfer is explored. Tabular comparison with some special cases of published data is done and good agreement is found. It is recorded that, the variable thermophysical properties of the fluid are more likely to promote the rate of heat transfer, Q_w as compared to fluid having constant properties

Assessment Of Pond Water Quality Of Thakurgaon Sadar Upazila For Fish Production

During dry season, physico-chemical properties of waters from 30 ponds of Thakugaon Sadar Upazila, Thakurgaon, Bangladesh were analyzed for its quality and suitability for aquaculture. The variation in the physico-chemical parameters of the aquaculture ponds above or below standard values has potential effects on the health and productivity of aquaculture. Overall, we found that the pond water were acidic to neutral in nature (pH varied from 6.0 to 7.2) and could be suitable for aquaculture. The dissolved oxygen (DO) concentration was suitable for fish production but more DO level should be present for all aquatic life especially for fish production. Chemical oxygen demands (COD) of all pond waters were within the permissible limits for fish production. The temperature values were remained within the standard values in all the aquaculture ponds. Pond water samples contained Ca2+, Mg2+ and Na+ as the dominant cations and HCO3- and Cl- were the dominant anions. All samples were within soft class regarding hardness. Based on Zn2+, Mn2+, Fe3+, SO42-, NO3- and Cl- all pond water samples were within the safe limit for fish production during dry period. Int. J. Agril. Res. Innov. & Tech. 3 (1): 29-34, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.1605

Singularity in Gravitational Collapse of Plane Symmetric Charged Vaidya Spacetime

We study the final outcome of gravitational collapse resulting from the plane symmetric charged Vaidya spacetime. Using the field equations, we show that the weak energy condition is always satisfied by collapsing fluid. It is found that the singularity formed is naked. The strength of singularity is also investigated by using Nolan's method. This turns out to be a strong curvature singularity in Tipler's sense and hence provides a counter example to the cosmic censorship hypothesis.Comment: 8 pages, accepted for publication in Mod. Phys. Lett

Modulation of Telomeres in Alternative Lengthening of Telomeres Type I Like Human Cells by the Expression of Werner Protein and Telomerase

The alternative lengthening of telomeres (ALT) is a recombination-based mechanism of telomere maintenance activated in 5–20% of human cancers. In Saccharomyces cerevisiae, survivors that arise after inactivation of telomerase can be classified as type I or type II ALT. In type I, telomeres have a tandem array structure, with each subunit consisting of a subtelomeric Y′ element and short telomere sequence. Telomeres in type II have only long telomere repeats and require Sgs1, the S. cerevisiae RecQ family helicase. We previously described the first human ALT cell line, AG11395, that has a telomere structure similar to type I ALT yeast cells. This cell line lacks the activity of the Werner syndrome protein, a human RecQ helicase. The telomeres in this cell line consist of tandem repeats containing SV40 DNA, including the origin of replication, and telomere sequence. We investigated the role of the SV40 origin of replication and the effects of Werner protein and telomerase on telomere structure and maintenance in AG11395 cells. We report that the expression of Werner protein facilitates the transition in human cells of ALT type I like telomeres to type II like telomeres in some aspects. These findings have implications for the diagnosis and treatment of cancer

Synthesis and antibacterial evaluation of 2-(1,3- Benzodioxol-5-ylcarbonyl)arylsulfonohydrazide derivatives

Purpose: To study the antibacterial activity of various sulfonamides derived from 1,3-benzodioxol-5- carbohydrazide.Methods: The synthesis involved the conversion of 1,3-benzodioxol-5-carboxylic acid (1) to ethyl 1,3- benzodioxol-5-carboxylate (2) and then to 1,3-benzodioxol-5-carbohydrazide (3). The target molecules, 2-(1,3-benzodioxol-5-ylcarbonyl)arylsulfonohydrazide derivatives (5a-l) were synthesized through a benignant method from aqueous medium by the reaction of 3 and arylsulfonyl chlorides (4a-l). The structural formulae of the synthesized compounds were characterized by infra red spectroscopy (IR), proton nuclear magnetic resonance (1H-NMR) and electron impact mass spectrometry (EI-MS). The compounds were screened for in vitro antibacterial activity by determining their minimum inhibitory concentration (MIC).Results: The molecule, 5k, bearing 2-hydroxy-3,5-dichlorophenyl group exhibited the highest activity with MIC of 11.92 ± 3.40 (S. typhi), 8.37 ± 2.22 (E. coli), 9.28 ± 2.31 (P. aeroginosa), 11.76 ± 1.30 (B. subtilis) and 10.30 ± 1.63 (S. aureus) μmoles/L relative to that of ciprofloxacin with 9.42 ± 1.09, 8.02 ± 2.17, 8.11 ± 1.32, 8.88 ± 2.00 and 9.23 ± 1.87 μmoles/L respectively.Conclusion: The most potent of the synthesized compounds (5k) posesses moderate activity against all the bacterial strains, while 5g remained completely inactive.Keywords: 1,3-Benzodioxol-5-carboxylic acid, Antibacterial activity, Sulfonohydrazide, Synthesi

Two-phase Natural Convection Dusty Nanofluid Flow

An analysis is performed to study the two-phase natural convection flow of nano fluid along a vertical wavy surface. The model includes equations expressing conservation of total mass, momentum and thermal energy for two-phase nano fluid. Primitive variable formulations (PVF) are used to transform the dimensionless boundary layer equations into a convenient coordinate system and the resulting equations are integrated numerically via implicit finite difference iterative scheme. The effect of controlling parameters on the dimensionless quantities such as skin friction coefficient, rate of heat transfer and rate of mass transfer is explored. It is concluded from the present analysis, that the diffusivity ratio parameter, N_A and particle-density increment number, N_B have pronounced influence on the reduction of heat transfer rate

How to understand Pakistan’s hybrid regime: the importance of a multidimensional continuum

Pakistan has had a chequered democratic history but elections in 2013 marked a second turnover in power, and the first transition in Pakistan’s history from one freely elected government to another. How do we best categorize (and therefore understand) political developments in Pakistan? Is it now safe to categorize it as an electoral democracy or is it still a hybrid case of democracy? Using the Pakistani case as an example, this article argues that hybrid regimes deserve consideration as a separate case (rather than as a diminished sub type of democracy or authoritarianism), but must be categorised along a multidimensional continuum to understand the dynamics of power within the political system