Flutter analysis and prevention for wings with large concentrated inertias

The influence of concentrated inertias on the flutter characteristics of a uniform cantilever wing were investigated both by experimental and by theoretical methods. The experimental work consisted of wind tunnel tests on a segmented wing model on which concentrated masses in the shape of large pods could be mounted at a number of spanwise and chordwise positions. The weight of these pods was comparable to the weight of the bare wing, and their pitching moment of inertia was varied to values up to ten times the pitching moment of inertia of the bare wing. The influence of the spanwise and chordwise position of these pods on the flutter speed was investigated. In order to assess the influence of the aerodynamic shape of the pods, four different pods were tested, each having a different aerodynamic shape. The effect of adding horizontal fins to the trailing edge of the pods was also investigated as a means of increasing the aerodynamic damping and hence the flutter stability. [Continues.

Investigation on Geosynthetic Reinforced Two Layered Soil System

Use of geosynthetics for flexible pavements founded on expansive soil subgrade is one of feasible and economic solution to minimize the undulation and required pavement thickness. In this present investigation the effect of inclusion of the geosynthetic reinforcement on California Bearing Ratio (CBR) value of a two layered soil system with black cotton soil at bottom and granular soil at top as a buffer layer, with different thickness configuration and geotextiles of different physical and mechanical properties was studied by laboratory and field California bearing ratio tests. Thickness of flexible pavement over the two layer soil system of different thickness configurations was estimated for unreinforced and reinforced two layered soil system by the method suggested by United States Army Corps of Engineers and Indian Road Congress. The reduction (%) in the thickness of pavement due to inclusion of geotextiles has been observed in the investigation. The reduction in thickness of pavement can be achieved up to 53.53% depending upon the thickness configuration and the type of the geotextile used. The results have shown that the field CBR tests can yield the results in conformity with the values obtained in the laboratory test

Fragment based tracking for scale and orientation adaptation

In this work, we propose a simple yet highly effective algorithm for tracking a target through significant scale and orientation change. We divide the target into a number of fragments and tracking of the whole target is achieved by coordinated tracking of the individual fragments. We use the mean shift algorithm to move the individual fragments to the nearest minima, though any other method like integral histograms could also be used. In contrast to the other fragment based approaches, which fix the relative positions of fragments within the target, we permit the fragments to move freely within certain bounds. Furthermore, we use a constant velocity Kalman filter for two purposes. Firstly, Kalman filter achieves robust tracking because of usage of a motion model. Secondly, to maintain coherence amongst the fragments, we use a coupled state transition model for the Kalman filter. Using the proposed tracking algorithm, we have experimented on several videos consisting of several hundred frames length each and obtained excellent results

Novel Framework for Navigation using Enhanced Fuzzy Approach with Sliding Mode Controller

The reliability of any embedded navigator in advanced vehicular system depends upon correct and precise information of navigational data captured and processed to offer trustworthy path. After reviewing the existing system, a significant trade-off is explored between the existing navigational system and present state of controller design on various case studies and applications. The existing design of controller system for navigation using error-prone GPS/INS data doesn‟t emphasize on sliding mode controller. Although, there has been good number of studies in sliding mode controller, it is less attempted to optimize the navigational performance of a vehicle. Therefore, this paper presents a novel optimized design of a sliding mode controller that can be effectively deployed on advanced navigational system. The study outcome was found to offer higher speed, optimal control signal, and lower error occurances to prove that proposed system offers reliable and optimized navigational services in contrast to existing system

Restoration of Equalization and Aeration Tanks of Effluent Treatment Plant at the Mysugar Factory, Mandya, Karnataka, India

This paper deals with the restoration measures resorted to strengthen the structure and prevent the leakage of the equalization and aeration tanks of effluent treatment plant in a sugar factory. These tanks showed distress at the hydraulic test itself before commissioning due to the failure of the reinforced concrete floor and bund lining on account of loss of support due to excessive deformation of the substratum. Extensive sand piling was resorted to strengthen the substratum before recasting the reinforced concrete floor and bund lining to ensure structural stability and prevent leakage. These tanks are functioning satisfactorily since two years after restoration serving the intended functions of the eflluent treatment

Identifying specific prefrontal neurons that contribute to autism-associated abnormalities in physiology and social behavior.

Functional imaging and gene expression studies both implicate the medial prefrontal cortex (mPFC), particularly deep-layer projection neurons, as a potential locus for autism pathology. Here, we explored how specific deep-layer prefrontal neurons contribute to abnormal physiology and behavior in mouse models of autism. First, we find that across three etiologically distinct models-in utero valproic acid (VPA) exposure, CNTNAP2 knockout and FMR1 knockout-layer 5 subcortically projecting (SC) neurons consistently exhibit reduced input resistance and action potential firing. To explore how altered SC neuron physiology might impact behavior, we took advantage of the fact that in deep layers of the mPFC, dopamine D2 receptors (D2Rs) are mainly expressed by SC neurons, and used D2-Cre mice to label D2R+ neurons for calcium imaging or optogenetics. We found that social exploration preferentially recruits mPFC D2R+ cells, but that this recruitment is attenuated in VPA-exposed mice. Stimulating mPFC D2R+ neurons disrupts normal social interaction. Conversely, inhibiting these cells enhances social behavior in VPA-exposed mice. Importantly, this effect was not reproduced by nonspecifically inhibiting mPFC neurons in VPA-exposed mice, or by inhibiting D2R+ neurons in wild-type mice. These findings suggest that multiple forms of autism may alter the physiology of specific deep-layer prefrontal neurons that project to subcortical targets. Furthermore, a highly overlapping population-prefrontal D2R+ neurons-plays an important role in both normal and abnormal social behavior, such that targeting these cells can elicit potentially therapeutic effects

Interface characterization of all-perovskite oxide field effect heterostructures

All-oxide devices consisting of Niobium-doped Strontium Titanate (Nb:STO)/Strontium Titanate (STO)/Lanthanum Strontium Cuprous Oxide (LSCO) heterostructures were fabricated and characterized electrically for their interface properties through capacitance-voltage (C-V) and current-voltage (I-V) techniques, in the context of electric field effect studies. The C-V studies establish the occurrence of charge modulation in the LSCO channel. Absence of hysteresis in the C-V characteristic when the voltage is retraced suggests the absence of mobile ions in the gate oxide and slow interface traps. This is further corroborated by the absence of drift in the C-V characteristic and shift in the flat band voltage (V FB) when the device is subjected to temperature-bias aging. The interface state density obtained from V FB is ~1012/cm2. The uncompensated hole concentration in the LSCO channel calculated from the measured room temperature C-V data is ~1020/cm3 and is in good agreement with the expected hole concentration in LSCO. Current-time and current-voltage plots are invariant with respect to the polarity of the applied voltage up to ~5 V. This, in a structure with asymmetric interfaces, indicates that the electrical contacts to STO are non-blocking and the conduction through STO is bulk-limited in this voltage regime. Thickness dependent current and capacitance studies also corroborate the bulk-limited nature of conduction through the device in this voltage regime. However, I-V characteristic shows a rectifying nature beyond ~8 V indicating that the mechanism in this voltage regime could be interface limited

Congenital Toxoplasmosis with Aplastic Anemia: A Rare Association

Congenital toxoplasmosis is caused by transmission of an intracellular obligate coccidian protozoan (Toxoplasma gondii) via vertical transmission during pregnancy. The clinical manifestations are wide ranging from asymptomatic to intracranial calcifications, seizures, developmental delay, chorioretinal lesions and even fetal death. Aplastic anemia is one of the rare presentations of congenital toxoplasmosis. Hence, we are reporting a case of a 23-year-old male who presented to us with aplastic anemia due to congenital toxoplasmosis. Thus, congenital toxoplasmosis should always be considered as a cause when evaluating a case of aplastic anemia