Transient dynamics of laminated beams: an evaluation with a higher-order refined theory

A higher-order refined model with seven degrees of freedom per node and cubic axial, quadratic transverse shear and linear transverse normal strain components is presented for the transient dynamic analysis of composite and sandwich beams. This shear correction coefficient free theory considers each layer of the beam to be in a state of plane stress. A special lumping scheme is employed for the evaluation of the diagonal mass matrix and a central difference predictor scheme is used to solve the dynamic equilibrium equation. The excellent performance of the higher-order model in comparison with the first-order theory is clearly brought out through numerical experiments

Free vibration of higher-order sandwich and composite arches, Part I: formulation

A higher-order refined model with seven degrees of freedom per node is presented in this paper for the free vibration analysis of composite and sandwich arches. The strain field is modeled through cubic axial, cubic transverse shear and linear transverse normal strain components. As the cross-sectional warping is accurately modeled by this theory, it does not require any shear correction factor. The stress-strain relationship is derived from an orthotropic lamina in a three-dimensional state of stress. The proposed higher-order formulation is validated, in this first part, through arches with various curvatures, aspect ratios, boundary conditions and materials

EFFICIENT MICROPROPAGATION FROM COTYLEDONARY NODE CULTURES OF COMMIPHORA WIGHTII (ARN.) BHANDARI, AN ENDANGERED MEDICINALLY IMPORTANT DESERT PLANT

Commiphora wightii (Arn.) Bhandari, is a medicinal important desert species of the family Burseraceae. It is a well known for its valuable active principle found in its oleo-gum-resin (guggulsterone E and Z), which are used in drugs preparation for lowering the cholesterol level in human body. Due to its overexploitation, poor natural regeneration this valuable plant is on the verge of extinction and thus a IUCN Red listed species. In the present study we report development of an efficient micropropagation protocol from cotyledonary node of Commiphora wightii. Cotyledonary nodes were used as an explants and multiple microshoots were obtained on Murashige & Skoog (MS) medium supplemented with 2.68 µM a-Naphthalene acetic acid (NAA) and 4.44 µM 6-Benzylamino purine (BAP) and on 2.68 µM NAA; 4.44 µM BAP with additives (glutamine 684.2 µM; thiamine 29.65 µM; activated charcoal 0.3%) and various other hormonal combinations. Elongation of microshoot was significantly observed on the 2.46 µM Indole-3-butyric acid (IBA) and 2.22 µM BAP supplemented MS medium. Efficient rooting was obtained on pretreated microshoot (4.92 µM IBA for 24 hours) and followed by transfer to White’s medium without Plant Growth Regulators (PGR) and high concentration of activated charcoal (AC). Rooted micro-shoots were transferred to vermiculite and wetted with Hoagland’s solution for primary hardening for 4-5 weeks and then finally transferred to plastic cups containing vermiculite, placed in mist chamber. Plantlets were transferred to soil: FYM 1:1 containing poly-bags, then to green shade house for complete acclimatization and finally transplanted to the experimental field

A general partial discretizationmethodology for interlaminar stress computation in composite laminates

A two-point boundary value problem (BVP) is formed in the present work governed by a set of first-order coupled ordinary differential equations (ODEs) in terms of displacements and the transverse stresses through the thickness of laminate (in domain -h/2 < z < h/2) by introducing partial discretization methodology only in the plan area of the three dimensional (3D) laminate. The primary dependent variables in the ODEs are those which occur naturally on a plane z=a constant. An effective numerical integration (NI) technique is utilized for tackling the two-point BVP in an efficient manner. Numerical studies on cross-ply and angle-ply composite plates are performed and presented, involving both validation and solution of new problems

Balanites aegyptiaca (L.) Del. A Multipurpose and potential biodiesel tree species of the arid region

Abstract: Balanites aegyptiaca (L.) Del., commonly known as hingota or desert date is an evergreen xerophyte. This plant can survive in a wide range of climatic conditions. It can withstand high temperature, high light intensity, high wind velocity and severe drought. The fruits and roots of this plant contain diosgenin, which can be used in pharmaceutical industry in production of oral contraceptive and steroids. The seeds of this plant contain 30-60% oil, which is edible and used as cooking oil. The seed oil can also be used as biofuel as combustion energy of oil is comparable to that of diesel. Fruits are also being used in detergent industry. This plant also has been reported to have Bristol and larvicidal activity against some mosquitoes. The stem of the tree contains steroidal saponins, which have been shown to have an insect anti-feedant and molluscicidal properties. Beside this the leaves of this plant is a one of the favorite fodder among goats, so it can play an important role of fodder tree in the desert in severe drought. This plant can be listed among the plants, which are used as famine foods. The yield of this marvelous tree is about 125 Kg/tree/annum. So looking at the importance and nature of the plant, this plant species must be promoted as planting material in combating desertification programme and in stabilization of sand dunes. This plant can play significant role especially against soil erosion as it produces root sucker in nearby area, the clump of the root sucker can hold the soil for a long

Nations within a nation: variations in epidemiological transition across the states of India, 1990–2016 in the Global Burden of Disease Study

18% of the world's population lives in India, and many states of India have populations similar to those of large countries. Action to effectively improve population health in India requires availability of reliable and comprehensive state-level estimates of disease burden and risk factors over time. Such comprehensive estimates have not been available so far for all major diseases and risk factors. Thus, we aimed to estimate the disease burden and risk factors in every state of India as part of the Global Burden of Disease (GBD) Study 2016

Numerical analysis of elastic plates with two opposite simply supported ends by segmentation method

A method for the numerical analysis of elastic plates with two opposite simply supported ends is presented. A variety of boundary conditions including the mixed and the nonhomogeneous types can be prescribed along either of the remaining two opposite edges. Numerical results are presented for the three examples. Based on the comparisons made with the results available elsewhere, it is concluded that the present method is efficient, economical, reliable and very accurate.© Elesvie

Numerical analysis of thick plates

Bending behaviour of a rectangular plate is analysed with the help of a refined higher order theory. The theory is based on a higher order displacement model and the three-dimensional Hooke's laws for plate material, giving rise to a more realistic quadratic variation of the transverse shearing strains and linear variation of the transverse normal strain through the plate thickness. It is shown that the segmentation method for the numerical analysis of plates simply supported on two opposite edges can be considered to be the most competitive method in terms of efficiency, economy, reliability and accuracy in such applications.© Elsevie