Control of vortex shedding behind circular cylinder for flows at low reynolds numbers

It has been observed by researchers in the past that vortex shedding behind circular cylinders can be altered, and in some cases suppressed, over a limited range of Reynolds numbers by proper placement of a second, much smaller, 'control' cylinder in the near wake of the main cylinder. Results are presented for numerical computations of some such situations. A stabilized finite element method is employed to solve the incompressible Navier-Stokes equations in the primitive variables formulation. At low Reynolds numbers, for certain relative positions of the main and control cylinder, the vortex shedding from the main cylinder is completely suppressed. Excellent agreement is observed between the present computations and experimental findings of other researchers. In an effort to explain the mechanism of control of vortex shedding, the streamwise variation of the pressure coefficient close to the shear layer of the main cylinder is compared for various cases, with and without the control cylinder. In the cases where the vortex shedding is suppressed, it is observed that the control cylinder provides a local favorable pressure gradient in the wake region, thereby stabilizing the shear layer locally

Laser induced elastico mechano luminescence of SrAl2O4 : Eu phosphor

When γ – irradiated elastic mechano luminescent materials SrAl2O4 : Eu are exposed to 1060 nm infrared pulse of nanosecond duration from CO2 laser, then stress produced in the crystals excites visible luminescence due to piezoelectric field in SrAl2O4 : Eu phosphor because they are non – centro symmetric.  In the present investigation SrAl2O4 : Eu crystals are given laser shocks and ML intensity recorded. During laser induced shocks, ML intensity increases linearly with stress and attains a peak value at a particular time and then decays exponentially with time. A theoretical approach has been proposed to explain the experimental results.&nbsp

Characteristic study, its identification and self-tuned approach to control hydro-power plants

The water time constant and mechanical time constant greatly influences the power and speed oscillations of hydro-turbine-generator unit. This paper discusses the turbine power transients in response to different nature and changes in the gate position. The work presented here analyses the characteristics of hydraulic system with an emphasis on changes in the above time constants. The simulation study is based on mathematical first-, second-, third- and fourth-order transfer function models. The study is further extended to identify discrete time-domain models and their characteristic representation without noise and with noise content of 10 & 20 dB signal-to-noise ratio (SNR). The use of self-tuned control approach in minimising the speed deviation under plant parameter changes and disturbances is also discussed

In silico de novo design of NNRTIs of HIV-1: Functional group based computational molecular modelling approach

1484-1493Seven novel lead compounds, acting as NNRTIs of HIV-1, are extracted from a database of, in silico de novo designed, 500 compounds. Functional group based computational molecular modelling techniques are used for such design of Acylthiocarbamate derivatives. Effect of structural characteristics on the antiviral activity of these derivatives has also been studied. Statistical regression techniques namely, Non-linear (Back Propagation Neural Network, Support Vector Machine) and linear (Multiple Linear) chemometric regression methods are used in developing the relationships of Kier-Hall Electrotopological State Indices (ERingA, EO8, EN9, EO14, ES16, EN17, EO19, ER, and ER1) with the HIV-1 antiviral activity. The relative potentials of these methods are also assessed and the results suggest that BPNN (r2 = 0.845, MSE = 0.142, q2 = 0.818) describes the relationship between the descriptors and antiviral activity in a relatively better manner than SVM-ε-radial (r2 = 0.844, MSE = 0.144, q2 = 0.807) and MLR (r2 = 0.836, MSE = 0.150, q2 = 0.805)

Energy Budget of Crops and Weed Management to Enhance Crop Productivity in Cold Arid Ladakh Region

Small scale agriculture is still the predominant characteristic of the Ladakh. It still has a great role in the economy. The region produces barley, wheat, vegetables and also involved in rearing livestock. The farming systems are unique and adapted to the harsh environmental conditions of Ladakh. Currently, the largest commercial agricultural produce is vegetable, which is sold in large quantity to defence establishments and as well as in the local market. It was recorded that production remains mainly in the hands of small land owners. In all the surveyed villages, majority of area (75%) is under vegetable crops as compared to cereals such as wheat and barley (25%). Efforts/ energy (unit in each case= value X 105 k cal/ha/year) being put to grow vegetables are significantly higher than the total output and the situation is just reverse in case of cereals. Survey revealed the need of small scale interventions including scientific weed management. From total energy point of view, staple crop production was found to be energy efficient. Even though subsistence-oriented production remains the economic mainstay, livelihood strategies have diversified in the light of growing geostrategic relevance and significant socio-economic changes

What makes brands achieve iconic status?

We propose that brands do not achieve iconic status by chance. This article focuses on how brands manage iconic status effectively. Drawing on an exploratory study of iconic brands, we identify a brand's ability to inspire consumers and connect with them on a personal level as well as its visual identity and presence in consumers' mind as critical elements of brand status. Consumers' perceptions of a sample of brands were investigated through in-depth interviews, followed by the examination of these brands' activities through case-study analyses. The alignment between brand strategies and the relevant features highlighted by consumers was then assessed. A comprehensive framework for achieving iconicity is presented and discussed.Working Pape

Weedy diversity of subsistence agriculture and their traditional uses in cold arid region of India

810-821In Ladakh, a cold arid region, subsistence agriculture has been in practice and is associated with livestock rearing in very small-scale stone-built terrace farming. Due to poor resources, public distribution systems, import/mutual exchange of plant materials and higher labour cost, high-altitude default organic farming has become a complex activity where weeds have become a recurrent problem. Moreover, they have become an integral part of fodder resources under small-scale stone-built terraced farming in barren ecosystems for enriching straw with supplementary weedy stuff. As a result, cropped areas suffer severe weed pressure as it requires 4-5 weedings under high-altitude solar radiation. An intensive survey revealed that the majority of weeds constituted of Amaranthaceae, Asteraceae, Poaceae and Fabaceae families, and they varied attitudinally. In this region, weeds are the major associated plant species, limiting the performance of crops in terms of seed quality and yields significantly. Hence, weed menace is overlooked in crops that impact the invasive weedy species to move upward to high altitudes under climate change. Conversely, people across this region have identified many of the weedy species for their day-to-day consumption as green leafy vegetables and for medicinal uses under the harsh climate of the cold arid region. This article describes the weedy species identified in crops and their utilization under low-land holding subsistence agriculture

Efficacy of potassium salt of glyphosate on weed control and yield in transgenic corn

A field experiment was carried out at Directorate of Weed Research, Jabalpur for the consecutive two years during kharif 2009 and 2010 to evaluate the weed control efficiency and crop productivity with K salt of glyphosate formulation in field conditions. Treatments consisted of two transgenic stacked hybrids named Hishell and 900M Gold applied with glyphosate as early post-emergence at 900, 1 800 and 3 600 g a.i./ha during kharif season of 2010 with two conventional hybrids namely Proagro-4640 and HQPM-1. Among the treatments, early post-emergence application of glyphosate at all doses registered lower weed density and higher weed control efficiency, i.e. 100% in all transgenic corn hybrids at 21 DAS and at harvest. Significantly higher numbers of cobs/plot were observed in transgenic hybrids as compared to conventional entries. While more cob length was observed with Hishell Transgenic hybrids at all doses as compared to 900 M Gold transgenic hybrids. Hishell transgenic hybrids at 3 600 g/ha registered significantly higher number of grains per row as compared to with its conventional control, 900 M Gold transgenic hybrid (1 800g/ha), 900 M Gold conventional and national checks. Significantly higher values of 20 cob weight, 20 cob grain weight and total cob weight was observed with Hishell and 900 M Gold transgenic hybrids as compared to other conventional hybrid entries and national checks. Hishell and 900 M Gold transgenic hybrids performed better with regard to grain yield ranging between 6-10 tonnes/ha which was approximately 3 to 4 times higher than the average yield of maize crop per ha, i.e. 2.30 tonnes/ha during both the years. Hishell at all rates of glyphosate application performed equally well in terms of yield but the yield of 900 M Gold decreased as the dose was enhanced from 1 800 to 3 600 g/ha during second year of experimentation