Showing papers by "Heritage Institute of Technology published in 2005"

Analytical Solution of a Dynamic System Containing Fractional Derivative of Order One-Half by Adomian Decomposition Method

Abstract: The fractional derivative has been occurring in many physical problems, such as frequency-dependent damping behavior of materials, motion of a large thin plate in a Newtonian fluid, creep and relaxation functions for viscoelastic materials, the PI λ D μ controller for the control of dynamical systems, etc Phenomena in electromagnetics, acoustics, viscoelasticity, electrochemistry, and materials science are also described by differential equations of fractional order The solution of the differential equation containing a fractional derivative is much involved Instead of an application of the existing methods, an attempt has been made in the present analysis to obtain the solution of an equation in a dynamic system whose damping behavior is described by a fractional derivative of order 1/2 by the relatively new Adomian decomposition method The results obtained by this method are then graphically represented and compared with those available in the work of Suarez and Shokooh [Suarez, L E, and Shokooh, A, 1997, An Eigenvector Expansion Method for the Solution of Motion Containing Fraction Derivatives, ASME J Appl Mech, 64, pp 629-635] A good agreement of the results is observed

PI3K-AKT pathway negatively controls EGFR-dependent DNA-binding activity of Stat3 in glioblastoma multiforme cells.

Abstract: Glioblastoma multiforme (GBM) cells frequently harbor amplification and/or gain-of-function mutation of the EGFR gene leading to the activation of multiple signaling pathways. Blockade of EGFR activation inhibited the activation of both AKT and Stat3 in U87 and D54 GBM cells and induced spontaneous apoptosis, which were associated with reduction in the steady-state level of Mcl-1. Surprisingly, inhibition of PI3 kinase (PI3K) activity, which in turn inhibited AKT activation, significantly increased the DNA-binding activity of Stat3 in U87 and D54 cells. This was not due to an increase in the level of tyrosine-phosphorylated Stat3. Conversely, ectopic expression of constitutively activated AKT significantly decreased the DNA-binding activity of Stat3 in 293T cells. Interestingly, blockade of protein phosphatase 2A activity in GBM or 293T cells by calyculin A, which activated AKT, stabilized the phosphorylation of multiple Ser/Thr residues that were located in the transactivation domain (TAD) of Stat3 and this in turn completely ablated the DNA-binding activity of Stat3. Collectively, these results suggest that both Stat3 and AKT provide survival signals in U87 and D54 cells, and Ser/Thr phosphorylation of Stat3-TAD by the PI3K-AKT pathway negatively controls the DNA-binding function of Stat3.

Oxidative degradation of polyaniline during the chemical oxidative polymerization of aniline in aqueous methanol medium

Abstract: The course of chemical oxidative polymerization of aniline using ammonium persulfate as the initiator in acidic (1 M HCl) aqueous methanol (30 to 70 vol%) was studied spectrophotometrically. It was found that at temperatures greater than about 10 °C the reaction leads to degradation of polyaniline, the effect being greater with increasing methanol concentration. This is quite unlike the situation in aqueous ethanol where the product is the usual emeraldine hydrochloride form of polyaniline. Copyright © 2005 Society of Chemical Industry

Opening up powerful lines of communication

Abstract: Power line carrier communications (PLCC) is a technology that utilizes electricity power lines for the transmission of process, data, and voice signals. The basic principle behind this communication technique is that the signal is modulated with a high-frequency carrier signal; then this high-frequency signal is coupled to the power line for communication. This system enables easy implementation of concepts like prepaid electricity. PLCC is slowly gaining acceptance in the field of home controlling and remote metering as they do not require high data rates.

Borate Based Spintronic Materials in Bulk Form above Room Temperature

Abstract: Magnetization above room temperature (RT) is a necessary parameter for achieving practical application of spintronic devices. Magnetization above room temperature in bulk form has been achieved in nanocrystalline Mn-doped ZnO dispersed in borate matrix. A simple glass-ceramic route has been used for the preparation of these materials. The material-processing route used here is cheaper and easier than other routes used frequently. X-ray diffraction (XRD) study reveals that the Mn-doped ZnO was in nanocrystalline form. Since these nanocrystals are dispersed in a glass matrix, they will be protected from agglomeration, so size will remain controlled, which affects the magnetization. There are no possibilities of an extrinsic origin such as ferromagnetic impurity segregation, etc. for this magnetization.

Fisher Information: Quantum Uncertainty Relation

Abstract: The paper deals with the reformulation of quantum uncertainty relation involving position and momentum of a particle on the basis of the Kerridge measure of inaccuracy and the Fisher information.