1,911 research outputs found
Determination of principal stress in birefringent composites by hole-drilling method
The application of transmission photoelasticity to stress analysis of composite materials is discussed.The method consists in drilling very small holes at points where the state of stress has to be determined. Experiments are described which verify the theoretical predicitons. The limitations of the method are discussed and it is concluded that valuable information concerning the state of stress in a composite model can be obtained through the suggested method
Photoelastic studies of advanced lap joint concept
Photoelasticity was introduced as a quantitative tool in the experimental stress analysis of anisotropic birefringent composite model materials. The investigation was divided into three parts: (1) separation of principal stresses or strains, (2) photoelastic calibration, and (3) development of model-prototype relations
Development of computer program NAS3D using Vector processing for geometric nonlinear analysis of structures
An algorithm for vectorized computation of stiffness matrices of an 8 noded isoparametric hexahedron element for geometric nonlinear analysis was developed. This was used in conjunction with the earlier 2-D program GAMNAS to develop the new program NAS3D for geometric nonlinear analysis. A conventional, modified Newton-Raphson process is used for the nonlinear analysis. New schemes for the computation of stiffness and strain energy release rates is presented. The organization the program is explained and some results on four sample problems are given. The study of CPU times showed that savings by a factor of 11 to 13 were achieved when vectorized computation was used for the stiffness instead of the conventional scalar one. Finally, the scheme of inputting data is explained
Structural efficiency studies of corrugated compression panels with curved caps and beaded webs
Curved cross-sectional elements are employed in structural concepts for minimum-mass compression panels. Corrugated panel concepts with curved caps and beaded webs are optimized by using a nonlinear mathematical programming procedure and a rigorous buckling analysis. These panel geometries are shown to have superior structural efficiencies compared with known concepts published in the literature. Fabrication of these efficient corrugation concepts became possible by advances made in the art of superplastically forming of metals. Results of the mass optimization studies of the concepts are presented as structural efficiency charts for axial compression
Linear and Nonlinear Optical Properties of Mn doped Benzimidazole Thin Films
In the present work, the Mn doped benzimidazole (BMZ) thin films were
prepared by simple chemical bath deposition technique. The material was
directly deposited as thin film on glass substrates and the metal concentration
in the solution was varied in weight percentage in order to investigate the
dopant effect on the properties of thin films. Similarly, the Mn doped BMZ
films were deposited in different solution temperature to study the effect of
deposition temperature on the properties of thin films. The PXRD and FT-IR
spectroscopy are used to study the structural and the presence of functional
groups in the BMZ medium. Depending upon the solution temperature, thickness of
the films varying from 0.6 to 1.2 {\mu}m and the optical transparency of the
samples increases with the increasing temperature up to 50 {\deg}C. Second
Harmonic Generation (SHG) efficiency of the films is measured for all the
films. Third order nonlinear optical properties of the films were analyzed
using Z-scan technique. The experimental results show that Mn doped BMZ films
exhibits saturation absorption and negative nonlinearity.Comment: This has been presented in DAE 58th Solid State Symposium held at
Thapar University, Patiala, Punjab, India. Will be published in AIP
conference proceedings soo
Extension of oblique incidence method to photo-orthotropic-elasticity
With the interpretation of isochromatic and isoclinic fringes in transparent, birefringent, orthotropic composites established, efforts were in progress to determine the individual values of the principal stresses or strains. Several methods utilize the photoelastic results only partially and rely on numerical procedures. Others attempt to obtain the required information based entirely on experimental data. The classical oblique incidence technique as applied to transversely isotropic birefringent composites, is presented. The proposed extension is verified by applying it to the problem of an orthotropic half-plane subjected to an edge-load
Photoelastic techniques for the complete determination of stresses in composite structures
Three methods of photoelastic analysis are examined. The first method is an extension of the oblique incidence technique in which the model (or the light beam) is rotated about one of the material symmetry axes. In the second method, transmission and reflection photoelastic responses are combined. The third method requires the drilling of small holes and the determination of the fringe orders at selected points on the hole boundary. The three methods are applied to an orthotropic circular disk under diametral compression. Results are compared with strain gage data
Development of the Magnetic Excitations of Charge-Stripe Ordered La(2-x)Sr(x)NiO(4) on Doping Towards Checkerboard Charge Order
The magnetic excitation spectrums of charge stripe ordered La(2-x)Sr(x)NiO(4)
x = 0.45 and x = 0.4 were studied by inelastic neutron scattering. We found the
magnetic excitation spectrum of x = 0.45 from the ordered Ni^2+ S = 1 spins to
match that of checkerboard charge ordered La(1.5)Sr(0.5)NiO(4). The distinctive
asymmetry in the magnetic excitations above 40 meV was observed for both doping
levels, but an additional ferromagnetic mode was observed in x = 0.45 and not
in the x = 0.4. We discuss the origin of crossover in the excitation spectrum
between x = 0.45 and x = 0.4 with respect to discommensurations in the charge
stripe structure.Comment: 4 Figures. To be appear in the J. Kor. Phys. Soc. as a proceedings
paper from the ICM 2012 conferenc
Determinants of fixed investment : a study of Indian private corporate manufacturing sector
This paper analyses the determinants of fixed investment in the
Indian Private Corporate Manufacturing sector for the period 1973-2002,
using Annual Survey of Industries Data. It is argued that economic policy
of a nation is crucial in determining the investment behaviour in
developing countries rather than the traditional factors like output and
profit. Against the background of the financial sector deregulation
initiated in India since 1991, this study makes an attempt to analyse
whether the traditional factors or the economic policy variables plays a
major role in determining investment behaviour. A reduced form equation
derived from the neoclassical investment theory is used for the empirical
analysis. Financial Liberalisation Index is constructed for India for the
analysis. The results show that, the traditional determinants like output
and profit still plays a major role in determining corporate investment
rather than the policy variables. Though aggregate financial liberalisation,
and more prominently domestic financial liberalisation produced an
environment conducive for investment, it could not succeed in creating
a sustained increase in capital formation in the post reform period. In
other words, firms consider the demand factor, internal liquidity position
and past investment decisions etc as the major indicators for future
investment. Only index shows strong positive association with corporate
investment is index of money market liberalisation. It is also found that
there is significant negative association between index of capital account
liberalisation and corporate investment. The negative and significant
relationship with index of capital account liberalisation and investment
raises many concerns over the credibility of external (international)
financial reforms.
Keywords: Investment, Manufacturing
JEL Classification: E22, O1
The pervasive nature of unconscious social information processing in executive control
Humans not only have impressive executive abilities, but we are also fundamentally social creatures. In the cognitive neuroscience literature, it has long been assumed that executive control mechanisms, which play a critical role in guiding goal-directed behavior, operate on consciously processed information. Although more recent evidence suggests that unconsciously processed information can also influence executive control, most of this literature has focused on visual masked priming paradigms. However, the social psychological literature has demonstrated that unconscious influences are pervasive, and social information can unintentionally influence a wide variety of behaviors, including some that are likely to require executive abilities. For example, social information can unconsciously influence attention processes, such that simply instructing participants to describe a previous situation in which they had power over someone or someone else had power over them has been shown to unconsciously influence their attentional focus abilities, a key aspect of executive control. In the current review, we consider behavioral and neural findings from a variety of paradigms, including priming of goals and social hierarchical roles, as well as interpersonal interactions, in order to highlight the pervasive nature of social influences on executive control. These findings suggest that social information can play a critical role in executive control, and that this influence often occurs in an unconscious fashion. We conclude by suggesting further avenues of research for investigation of the interplay between social factors and executive control
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