Synthesis of Nanocrystalline Alumina Using Egg White

A new simplified route to prepare nanocrystalline alumina powders is proposed. The method involved the use of freshly extracted egg white (ovalbumin) and aluminum nitrate in an aqueous medium. Changes in ionic strength upon addition of aluminum nitrate resulted in gelation of ovalbumin. The added metal ions were dispersed in the gelled ovalbumin matrix. Heat treatment of the gelled mass resulted in nanosized γ alumina at as low a temperature as 330°C. TEM analysis showed that the particle size ranged from 15 to 80 nm.     

Recognizing large isolated 3-D objects through next view planning using inner camera invariants.

Most model-based three-dimensional (3-D) object recognition systems use information from a single view of an object. However, a single view may not contain sufficient features to recognize it unambiguously. Further, two objects may have all views in common with respect to a given feature set, and may be distinguished only through a sequence of views. A further complication arises when in an image, we do not have a complete view of an object. This paper presents a new online scheme for the recognition and pose estimation of a large isolated 3-D object, which may not entirely fit in a camera's field of view. We consider an uncalibrated projective camera, and consider the case when the internal parameters of the camera may be varied either unintentionally, or on purpose. The scheme uses a probabilistic reasoning framework for recognition and next-view planning. We show results of successful recognition and pose estimation even in cases of a high degree of interpretation ambiguity associated with the initial view.     

On estimation of population mean using known coefficient of variation

For the estimation of population mean, a generalized class of estimators using known coefficient of variation C_y of the study variable y is proposed, its bias and mean square error (MSE) are found and its comparative study with the usual mean per unit estimator has been done. As an illustration, an empirical study is also included.     

Geometrically non-linear formulation for two dimensional curved beam elements

This paper presents a geometrically non-linear formulation using a total lagrangian approach for the two dimensional curved beam elements. The beam element is derived using linear, paralinear and cubic-linear plane stress elements. The basic element geometry is constructed using the coordinates of the nodes on the element center line (η = 0) and the nodal point normals. The element displacement field is described using two translations of the node on the center line and a rotation about the axes normal to the plane containing the center line of the element. The existing beam element formulations are restricted to small nodal rotations between two successive load increments. The element formulation presented here removes such a restriction. This is accomplished by retaining non-linear nodal rotation terms in the definition of the displacement field and the consistent derivation of the element properties. The formulation presented here is very general and yet can be made specific by selecting appropriate non-linear functions representing the effects of nodal rotations. The element properties are derived and presented in detail. Numerical examples are also presented to demonstrate the behavior and the accuracy of the two dimensional beam elements for geometrically non-linear applications. In all cases comparisons made with theory and/or other published data show that the beam elements product accurate results and permit large load increments with good convergence characteristics.     

p-version least-squares finite element formulation for convection-diffusion problems

This paper presents a p-version least-squares finite element formulation of the convection-diffusion equation. The second-order differential equation describing convection-diffusion is reduced to a series of equivalent first-order differential equations for which the least-squares formulation is constructed using the same order of approximation for each of the dependent variables. The hierarchical approximation functions and the nodal variable operators are established by first constructing the one-dimensional hierarchical approximation functions of orders pξ and pη and the corresponding nodal variable operators in ξ and η-direction and then taking their products. Numerical results are presented and compared with analytical and numerical solutions for a two-dimensional test problem to demonstrate the accuracy and the convergence characteristics of the present formulation. The Gaussian quadrature rule used to calculate the numerical values of the element matrices, vectors as well as the error functional I(E), is established based on the highest degree of the polynomial in the integrands. It is demonstrated that this quadrature rule with the present p-version formulation produces excellent results for very low as well as extremely high Peclet numbers (10-10⁶) and, furthermore, the error functional I (sum of the integrals of E²) is a monotonically decreasing function of the number of degrees of freedom as the p-levels are increased for a fixed mesh. It is shown that exact integration with the h-version (linear and parabolic elements) produces inaccurate solutions at high Peclet numbers. Results are also presented using reduced integration. It is shown that the reduced integration with p-version produces accurate values of the primary variable even for relatively low p-levels but the error functional I (when calculated using the proper integration rule) has a much higher value (due to errors in the derivatives of the primary variable) and is a non-monotonic function of the degrees of freedom as p-levels are increased for a fixed mesh. Similar behaviour of the error functional I is also observed for the h-models using linear elements when reduced integration is used. Although the h-models using parabolic elements produce monotonic error functional behaviour as the number of degrees of freedom are increased, the error values are inferior to the p-version results using exact integration.     

Transition finite elements for three-dimensional stress analysis

This paper presents isoparametric formulation for the three-dimensional transition finite elements. The transition finite elements are necessary for applications requiring the use of three-dimensional isoparametric solid elements and the curved shell elements. These elements provide proper connections between the two portions of the structure modelled with three-dimensional solids and the curved shell elements. The element properties are derived and presented in detail. Numerical examples are also presented to demonstrate the accuracy and the applications of such elements in three-dimensional stress analysis.     

Lumped mass matrices with non−zero inertia for general shell and axisymmetric shell elements

A diagonal lumped mas formulation with non?zero inertia terms is presented for Ahmad's general shell element. The effect of co?ordinate transformation of the mas matrix is demonstrated. Due to arbitray co?ordinate transformation on nodal variables, the diagonal lumped mas matrix becomes a banded matrix of half bandwidth three. It is shown that with some approximations this matrix can be made diagnoal without effecting the results appreciably. Numerical examples are presented to illustrate the accuracy of the formulation. Similar lumped mass matrix formulation is also given for axisymmetric shell elements.     

The oviposition and development of Sitophilus oryzae (L.) in different high-yielding varieties of wheat

Studies on the oviposition and development of Sitophilus oryzae in high-yielding varieties of wheat (PV-18, Sonora-64, Kalyan Sona, S-308 and S-307) were conducted at all combinations of the three temperatures, 19°C, 25°C and 30°C and four relative humidities, 45, 60, 75 and 90 per cent. Oviposition and development of the weevil were better on larger kernels. The rates of oviposition and development were affected by certain other factors besides the physical nature of the kernel and its bran and endosperm. According to the development index ($\text{log}\text{n}\text{Av}$) and number of eggs deposited, varieties in increasing order of suitability were Sonora-64 > PV-18 > Kalyan Sona > S-308 > S-307. Oviposition and development were best in varieties with the highest moisture content at any level of relative humidity. Oviposition and development were best at 75% r.h. or 15·0–15·5 per cent moisture content in all varieties. Oviposition and development rates were greater at 30°C and slower at 18°C than at 25°C. Of the conditions examined 30°C and 75% r.h. was the best for oviposition and development of S. oryzae.     

Rheological, textural and spectral characteristics of sorbitol substituted mango jam

Full replacement of sucrose with sorbitol is feasible in mango jam manufacturing. Dynamic rheological tests characterized mango jam manufactured with sucrose/sorbitol as a weak gel. Mango jam did not follow Cox-Merz or modified Cox-Merz rule. The storage- and loss- moduli increased with sucrose concentration up to 60%, but decreased at higher sucrose concentrations. Gel strength decreased with increasing sorbitol concentration because of weaker junction zones in pectin gel network. FTIR spectra revealed that C-O and C-C stretching vibrations are indicators of the gel strength because pectin polymeric chain network formation in fruit jam is due to hydrogen bonding and hydrophobic interactions.