The effects of rotational flow, viscosity, thickness, and shape on transonic flutter dip phenomena

The transonic flutter dip phenomena on thin airfoils, which are employed for propfan blades, is investigated using an integrated Euler/Navier-Stokes code and a two degrees of freedom typical section structural model. As a part of the code validation, the flutter characteristics of the NACA 64A010 airfoil are also investigated. In addition, the effects of artificial dissipation models, rotational flow, initial conditions, mean angle of attack, viscosity, airfoil thickness and shape on flutter are investigated. The results obtained with a Euler code for the NACA 64A010 airfoil are in reasonable agreement with published results obtained by using transonic small disturbance and Euler codes. The two artificial dissipation models, one based on the local pressure gradient scaled by a common factor and the other based on the local pressure gradient scaled by a spectral radius, predicted the same flutter speeds except in the recovery region for the case studied. The effects of rotational flow, initial conditions, mean angle of attack, and viscosity for the Reynold's number studied seem to be negligible or small on the minima of the flutter dip

The effects of transients on photospheric and chromospheric power distributions

We have observed a quiet Sun region with the Swedish 1-meter Solar Telescope (SST) equipped with CRISP Imaging SpectroPolarimeter. High-resolution, high-cadence, H$\alpha$ line scanning images were taken to observe different layers of the solar atmosphere from the photosphere to upper chromosphere. We study the distribution of power in different period-bands at different heights. Power maps of the upper photosphere and the lower chromosphere show suppressed power surrounding the magnetic-network elements, known as "magnetic shadows". These also show enhanced power close to the photosphere, traditionally referred to as "power halos". The interaction between acoustic waves and inclined magnetic fields is generally believed to be responsible for these two effects. In this study we explore if small-scale transients can influence the distribution of power at different heights. We show that the presence of transients, like mottles, Rapid Blueshifted Excursions (RBEs) and Rapid Redshifted Excursions (RREs), can strongly influence the power-maps. The short and finite lifetime of these events strongly affects all powermaps, potentially influencing the observed power distribution. We show that Doppler-shifted transients like RBEs and RREs that occur ubiquitously, can have a dominant effect on the formation of the power halos in the quiet Sun. For magnetic shadows, transients like mottles do not seem to have a significant effect in the power suppression around 3 minutes and wave interaction may play a key role here. Our high cadence observations reveal that flows, waves and shocks manifest in presence of magnetic fields to form a non-linear magnetohydrodynamic system.Comment: 11 pages, 11 Figures, 4 movies (will be available online in ApJ). ApJ (accepted

Some three dimensional elasto-dynamic solutions of layered shells

Three dimensional solutions for natural frequencies and mode shapes of layered composite shells obtained by using the finite layer method, are presented in this paper. Higher order theories for laminated shells are discussed

Nanoscale quantum dot infrared sensors with photonic crystal cavity

We report high performance infrared sensors that are based on intersubband transitions in nanoscale self-assembled quantum dots combined with a microcavity resonator made with a high-index-contrast two-dimensional photonic crystal. The addition of the photonic crystal cavity increases the photocurrent, conversion efficiency, and the signal to noise ratio (represented by the specific detectivity D*) by more than an order of magnitude. The conversion efficiency of the detector at Vb=–2.6 V increased from 7.5% for the control sample to 95% in the PhC detector. In principle, these photonic crystal resonators are technology agnostic and can be directly integrated into the manufacturing of present day infrared sensors using existing lithographic tools in the fabrication facility

Differential genotypical expression of a NEDD9 in normal and tumor tissues: a possible pharmacological target

Background: Neural precursor cell expressed developmentally down regulated-9 (NEDD9) is a scaffolding metastatic marker protein in multiple cancer types. Generally, the expression occurs during the embryonic development and depletes in adults. Expression of NEDD9 in adults leads to the progression of tumor which is sufficient for the cellular invasion. Elevated behavior of the gene mediates metastatic movement which includes protease dependent neovessel formation, invasion and migration of tumor cells from the site of origin to the distant tissues.Methods: The current study involves the screening and elucidation of differential expression of NEDD9 in normal and tumor subtypes with various tissues of mice by immunohistochemistry.Results: The validating approaches in the study, low expression of NEDD9 was observed in the normal tissues and predominance in the tumor subsets.Conclusions: The experimental analysis proven that NEDD9 expression is merely associated with tumor progression and the molecular mechanism of NEDD9 is restricted in the establishment of metastatic cascade. NEDD9 association in tumor prognosis which helps in the emergence of diagnostic and therapeutic approaches

Bounds and error control for eigenvalues

Control and estimation of errors are important but difficult aspects of any analysis from which the numerical results are necessarily approximate. The order of difficulty is greater for local or distributed quantities like stresses and displacements than for global Of integrated parameter~ like eigenvalues and stiffnesses. To really bound a desired quantity between a pair of dose upper and lower bounds one should obtain either an oscillatory but clear convergence or, preferably, two rapidly converging sequences one from above and the other from below. Application of the two complementary variational principles of energy and complimentary energy, when both are possible to apply, do yield upper and lower bound approximations. But these or other alternate methods are generally expensive. On the other hand it would be advantageous if one basic procedure could be perturbed in a simple manner to provide both lower and upper bounds and to refine the solution and control the errors without undue effort. This paper discusses this concept and presents three powerful methods to closely bound any desired parameter in a problem. These are particularly valuable for eigenvalue problems

Recent advances in central congenital hypothyroidism.

Central congenital hypothyroidism (CCH) may occur in isolation, or more frequently in combination with additional pituitary hormone deficits with or without associated extrapituitary abnormalities. Although uncommon, it may be more prevalent than previously thought, affecting up to 1:16 000 neonates in the Netherlands. Since TSH is not elevated, CCH will evade diagnosis in primary, TSH-based, CH screening programs and delayed detection may result in neurodevelopmental delay due to untreated neonatal hypothyroidism. Alternatively, coexisting growth hormones or ACTH deficiency may pose additional risks, such as life threatening hypoglycaemia. Genetic ascertainment is possible in a minority of cases and reveals mutations in genes controlling the TSH biosynthetic pathway (TSHB, TRHR, IGSF1) in isolated TSH deficiency, or early (HESX1, LHX3, LHX4, SOX3, OTX2) or late (PROP1, POU1F1) pituitary transcription factors in combined hormone deficits. Since TSH cannot be used as an indicator of euthyroidism, adequacy of treatment can be difficult to monitor due to a paucity of alternative biomarkers. This review will summarize the normal physiology of pituitary development and the hypothalamic-pituitary-thyroid axis, then describe known genetic causes of isolated central hypothyroidism and combined pituitary hormone deficits associated with TSH deficiency. Difficulties in diagnosis and management of these conditions will then be discussed.This work was supported by funding from the Wellcome Trust (Grant 100585/Z/12/Z, to N.S., Grant 095564/Z/11/Z, to K.C.)This is the final version of the article. It first appeared from Society for Endocrinology via http://dx.doi.org/10.1530/JOE-15-034

Microstrip Line Fed Leaky Wave Antenna with Shorting Vias for Wideband Systems

In this work a complex structured shorted vias microstrip leaky wave antenna is designed and analysed. A Leaky wave antenna is a travelling wave structure with complex propagation constant. When shorting vias are loaded in a periodic structure the fundamental resonant mode shows some stop band characteristics and some of the modes will strongly attenuated. Three different types of iterations are examined in this work with and without defected ground structures. The defected ground structure based leaky wave antennas are showing better performance characteristics with respect to efficiency and phase. A micro strip line feeding with impedance of 50 ohms at both ports are providing excellent impedance matching to the conducting path on the microstrip surface. The shorting vias are suppressing certain higher order frequency bands and providing excellent wide band characteristics with low loss

Prevalence of thyroid dysfunction and its association with controlled and uncontrolled type 2 diabetes mellitus in northern Andhra Pradesh population: a retrospective study

Background: The two important endocrinopathies, diabetes mellitus and thyroid dysfunction are interrelated to each other where the correlation is poorly understood. The thyroid dysfunction is more frequent in diabetics than general population. The present study was aimed to know the prevalence of thyroid dysfunction in type 2 diabetes mellitus (T2DM) and its association with controlled and uncontrolled T2DM.Methods: A retrospective study of 600 T2DM patients between 13-60 years of age with known thyroid status were included and the following parameters were examined: age, sex, body mass index (BMI), fasting blood sugar (FBS), HbA1C, free triiodothyronine (fT3), free tetraiodothyronine (fT4) and thyroid stimulating hormone (TSH).Results: The prevalence of thyroid dysfunction in T2DM patients was found to be 26.5% whereas 9% in healthy controls. Significantly elevated levels of FBS, HbA1C and TSH were observed whereas the levels of fT3, fT4 were found to be low in patients when compared to controls. Subclinical hypothyroidism (SCH) in diabetics (both controlled and uncontrolled) was more prevalent (15%) than it was found in healthy controls (5%). Similarly, overt hypothyroidism was also found to be high in diabetic patients (6%) as compared to healthy controls (2%). Significant difference (p <0.05) in the levels of TSH was found between group I (Controlled T2DM) and II (uncontrolled T2DM patients), also between groups II and III (Controls). Group II patients were found to have significant low levels of fT3 as compared to other two groups (Group I and III) (p<0.005).Conclusions: As SCH is more frequent in T2DM diabetes mellitus and untreated SCH patients have higher rate of complications, periodical screening is advised for thyroid dysfunction to prevent micro vascular and cardiovascular complications