An Analysis of Thermal-Bending Stresses in a Simply Supported Thin Elliptical Plate

In this paper, a transient thermal stress investigation on a simply supported thin elliptical plate during sectional heating with time-dependent temperature supply is considered. The solution of heat conduction equation with corresponding initial and boundary conditions is obtained by employing an integral transform approach. The governing equation solution for the small deflection theory is obtained and utilized to preserve the intensities of thermal bending moments, involving the Mathieu and modified functions and its derivatives. The deflection results show an approximately good agreement with the previously given results. It is also demonstrated that the temperature field in a circular solution could be resulted in a particular case of the present mathematical solution. The obtained numerical results utilizing computational implements are precise enough for practical purposes

Heat source thermoelastic problem in a hollow elliptic cylinder under time-reversal principle

The article investigates the time-reversal thermoelasticity of a hollow elliptical cylinder for determining the temperature distribution and its associated thermal stresses at a certain point using integral transform techniques by unifying classical orthogonal polynomials as the kernel. Furthermore, by considering a circle as a special kind of ellipse, it is seen that the temperature distribution and the comparative study of a circular cylinder can be derived as a special case from the present mathematical solution. The numerical results obtained are accurate enough for practical purposes

Thermoelastic stress analysis of a functionally graded transversely isotropic hollow cylinder in elliptical coordinates

This paper is concerned with the axisymmetric thermoelastic problem to investigate the influence of nonlinear heat conduction equation, displacement functions and thermal stresses of a functionally graded transversely isotropic hollow cylinder that is presented in the elliptical coordinate system. The method of integral transform technique is used to produce an exact solution of the heat conduction equation in which sources are generated according to a linear function of the temperature. An explicit exact solution of the governing thermoelastic equation is proposed when material properties are power-law functions with the exponential form of the radial coordinate. Numerical calculations are also carried out for Material I with the nearly isotropic feature, along with Material II as an anisotropic material and illustrated graphically. The validity of the solution is demonstrated by comparing with the previous results

Axisymmetric Thermoelastic Response in a Semi-elliptic Plate With Kassir’s Nonhomogeneity in the Thickness Direction

The main objective is to investigate the transient thermoelastic reaction in a nonhomogeneous semi-elliptical elastic plate heated sectionally on the upper side of the semi-elliptic region. It has been assumed that the thermal conductivity, calorific capacity, elastic modulus and thermal coefficient of expansion were varying through thickness of the nonhomogeneous material according to Kassir’s nonhomogeneity relationship. The transient heat conduction differential equation is solved using an integral transformation technique in terms of Mathieu functions. In these formulations, modified total strain energy is obtained by incorporating the resulting moment and force within the energy term, thus reducing the step of the calculation. The thermal deflection equation derived from the Berger approach is compared with Von Karman approaches, and its maximum normal stresses are determined. The numerical calculation is performed over the metal-metal based composite and graphically portrayed. Furthermore, by applying limiting conditions, the semi-elliptic region can be degenerate into a semi-circular plate. Results reveal that the highest tensile stress exists on the semi-circular core relative to the semi-elliptical core, suggesting the propagation of low heating due to insufficient heat penetration into the elliptic surface

Biodiversity assessment of sea cage farming sites in Gulf of Mannar, Tamil Nadu, India

Marine fin and shellfish farming is an age old practice across the globe to augment the seafood production and to supplement the protein rich food. The open sea cages are particularly advantageous for maintaining the brood stock of potential species like cobia (Rachycentron canadum) and silver pompano (Trachinotus blochii) for captive breeding. A large congregation of various bioresources are also found to be associated with cage farming (Imelda et al., 2010). In the present study, an attempt was made to understand the biodiversity of the cage farming area at Mandapam in Gulf of Mannar, India

Ecology and biodiversity of open sea cage farm at Mandapam, India

Farming of marine fin and shellfish species is an age old practice across the globe to augment the seafood demand and to supplement the rich protein food. Fin fish mariculture in India has been a recent initiative and the Central Marine Fisheries Research Institute was successful in developing captive breeding and seed production technique for cobia (Rachycentron canadum) and silver pompano (Trachinotus blochii). The open sea cages are particularly advantageous for maintaining the brood stock of potential species for captive breeding. However, the ecology of the cage farming sites is of paramount importance and should be conducive for the survival, health and growth of fishes that are farmed. In the present study, an attempt was made to understand the ecology and biodiversity of the cage farming area at Mandapam in Gulf of Mannar, south-east coast of India

कोच्ची की समुद्री स्फुटनशाला में मृदु प्रवाल लोबोफाइटम साक्रोफाइटोइडस का पालन

Culture of soft coral, labophytus sacrophytoides in marine hatchery at Koch

विशेष स्थानिकता और समुद्री जीव जतीयों की संपन्नता के प्रसंग में मान्नार खाडी आवास व्यवस्था की जैवविविधता

कृपया पूरा लेखा पढ

Corrosion inhibition capacity of two heterocyclic oximes on copper in nitric acid: electrochemical, quantum chemical and surface morphological investigations

Two heterocyclic oximes (E)-N-hydroxy-1-(pyridin-2-yl)methanimine (Hp2ylm) and (E)-N-hydroxy-1-(pyridin-3-yl)methanimine (Hp3ylm) were synthesized from pyridine-2-carbaldehyde and pyridine-3-carbaldehyde, respectively. These oximes were characterized by various spectroscopic tools like UV, IR, MASS and NMR. The inhibition capacity of these oximes against copper corrosion in 0.1 M HNO3 was determined by polarization and impedance spectroscopic studies (EIS). At all concentrations, Hp3ylm exhibited higher inhibition efficiency than Hp2ylm. Attempt was made to illustrate the mechanism of corrosion inhibition by these oximes with the help of adsorption isotherm, scanning electron microscopic (SEM) and quantum chemical studies

Nicotine-induced survival signaling in lung cancer cells is dependent on their p53 status while its down-regulation by curcumin is independent

<p>Abstract</p> <p>Background</p> <p>Lung cancer is the most lethal cancer and almost 90% of lung cancer is due to cigarette smoking. Even though nicotine, one of the major ingredients of cigarette smoke and the causative agent for addiction, is not a carcinogen by itself, several investigators have shown that nicotine can induce cell proliferation and angiogenesis. We observed that the proliferative index of nicotine is different in the lung cancer cell lines H1299 (p53-/-) and A549 (p53+/+) which indicates that the mode of up-regulation of survival signals by nicotine might be different in cells with and without p53.</p> <p>Results</p> <p>While low concentrations of nicotine induced activation of NF-κB, Akt, Bcl2, MAPKs, AP1 and IAPs in H1299, it failed to induce NF-κB in A549, and compared to H1299, almost 100 times higher concentration of nicotine was required to induce all other survival signals in A549. Transfection of WT-p53 and DN-p53 in H1299 and A549 respectively, reversed the mode of activation of survival signals. Curcumin down-regulated all the survival signals induced by nicotine in both the cells, irrespective of their p53 status. The hypothesis was confirmed when lower concentrations of nicotine induced NF-κB in two more lung cancer cells, Hop-92 and NCI-H522 with mutant p53 status. Silencing of p53 in A549 using siRNA made the cells susceptible to nicotine-induced NF-κB nuclear translocation as in A549 DN-p53 cells.</p> <p>Conclusions</p> <p>The present study reveals a detrimental role of nicotine especially in lung cancer patients with impaired p53 status and identifies curcumin as a potential chemopreventive.</p