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Byline: Manisha. Acharya, Javed. Farooqui, Abhishek. Dave, Deepali. Chaku, K. Ganguly, Animesh. Das, Umang. Mathur Purpose: To understand trends, awareness, influences and barriers to eye donation in Indian society. Methods: [...]

Purpose: The objective of the present work is to carry out simulation studies for prediction of nonlinear dynamic characteristics of functionally graded uniform beams. Methods: The material properties are considered to be varying simultaneously along thickness and length direction. Euler–Bernoulli beam theory is used to generate the constitutive relations and two distinct methodologies are employed, viz., whole domain method and finite element method. Geometric nonlinearity is incorporated in the methodology using Von Karman’s strain–displacement relations. Results: The results are presented as backbone curve and mode shape in free vibration and frequency–response curve and operational deflection shape in forced vibration. The effect of material gradation on dynamic behaviour is investigated using different values of material gradient parameter. The nonlinear system is seen to display hard spring behaviour. A comparative study between WDM and FEM also shows the correctness of present study. Conclusion: In free vibration, a similar trend has been found in all cases that natural frequency increases with response amplitude. This behaviour is due to the stretching effect associated with large deflection resulting in additional stiffening of the system. Increase in vibration frequencies with response amplitude is formally known as hardening type nonlinearity. The same is also observed in forced vibration analysis where the frequency–response curve bends towards right.

We study the linear stability of nondissipative flow of an electrically conducting fluid subject to non-axisymmetric disturbances in the following cases: (i) the radial flow of an incompressible fluid between two concentric porous circular cylinders in the presence of a radial magnetic field and (ii) axial flow of a compressible fluid between two concentric circular cylinders permeated by a helical magnetic field (0,B0?(r),B0z) in a cylindrical coordinate system. It is shown that in case (i), the flow is stable if the Alfvén velocity based on the undisturbed radial magnetic field exceeds the radial velocity due to suction or injection at the cylinder surfaces. In case (ii), it is found that under certain conditions the complex wave speed for an unstable mode lies within a circle of diameterWmax-Wmin, whereWmax andWmin are the maximum and minimum values of the axial velocity in the flow region. In the presence of a purely axial magnetic field, however, the complex wave speed for an unstable mode always lies within the above circle.

In this paper, we have used Case's analysis of the neutron transport equation to obtain a new set of quadrature coefficients for the discrete-ordinates method. We perform the transport calculations by this set of quadratures, dependent on the medium. We also use the orthogonality relations in the discrete case to derive the full-range formulation of the half-range problem. This solution can, indeed, be profitably used in the new discrete-ordinates method.

Eighteen patients (five normal and thirteen pathological) larynx were evaluated with high-resolution computed tomography (CT). In normal larynx CT helped us to show those areas which are invisible or difficult to examine by clinical examination, direct laryngoscopy, and conventional radiology e.g. pre-epiglotic space, paraglottic space, and the laryngeal framework. In pathological conditions, CT provided informations regarding deep penetration and inferior extension of tumour, cartilaginous invasion or laryngeal neoplasm from those arising from adjacent extralaryngeal structures. Though early invasion of laryngeal cartilage by neoplasm may occasionally be difficult with CT, yet it helped to determine the type of management in these types of cases.

The envelope gene of HTLV-III, the retrovirus directly linked to AIDS, encodes a protein of 856 amino acids. Our sequence analysis of the cloned HTLV-III (HXB-3) envgene and its comparison with other isolates reveal significant divergence, especially in the external portion of this protein. A large segment of the envgene (1800 bp) was inserted into the expression vector pEV-vrf3, and a corresponding 68 kd protein, which encompasses both the extracellular and the membrane-associated regions of the native protein, was produced in E. coli. Several smaller polypeptides, which appear to be internal initiation products, were also produced. All 50 AIDS patient sera obtained from different locations in the United States specifically recognized the bacterially synthesized envelope proteins, as judged by Western blots. This suggests that these proteins will be useful for the diagnosis of HTLV-III infection and possibly as a vaccine against AIDS.

The space-angle-energy dependent integro-differential equation of the neutron transport theory cannot be exactly solved analytically in its entire generality. Over the past three decades, there have been many research efforts to develop numerically efficient approximate methods to solve the neutron transport equation. In this paper, we will present a new approach to the neutron transport equation, which is suitable for numerical compiitations. To understand the limitations of the existing popular approximate methods, we first consider the exact solution of the one-speed transport equation in plane geometry

• Whole domain method and finite element method are used to formulate the dynamic problem. • The nonlinear dynamic behaviour of unidirectional and bidirectional functionally graded plates are studied. • Geometric nonlinearity is addressed here by using Von Karman type strain-displacement relation. • The results of free and forced vibration analyses are presented as backbone curves and frequency response curves respectively. • The results show that all plates exhibit hardening type nonlinearity. Present work attempts to study the nonlinear dynamic behaviour of bidirectional functionally graded plates (BFG) along with unidirectional functionally graded plates (UFG). For BFG plates the material is graded along the thickness and length simultaneously and two types of UFG plates are considered namely thickness-wise (TFG) and length-wise (AFG) plates. The dynamic problem is formulated using two different methods namely, whole domain method and finite element method. The constitutive relation for the former is generated using classical plate theory whereas Mindlin plate theory is used in the later. Geometric nonlinearity is addressed here by using Von Karman type strain-displacement relation. Both clamped and simply supported boundary conditions are considered and the plate is assumed to be under action of uniformly distributed external load. The results of free and forced vibration analyses are presented as backbone curves and frequency response curves respectively. The results show that all three plates exhibit hardening type nonlinearity. It is also seen that the effect of material gradation parameters is more profound in simply supported plates compared to clamped plates. Specifically, these parameters do not seem to have much effect on BFG clamped plates in free vibration. The outcome of the analysis is compared with those in existing literature and fair agreement is observed between them. [ABSTRACT FROM AUTHOR]