Voice stress analysis

In a study of the validity of eight candidate voice measures (fundamental frequency, amplitude, speech rate, frequency jitter, amplitude shimmer, Psychological Stress Evaluator scores, energy distribution, and the derived measure of the above measures) for determining psychological stress, 17 males age 21 to 35 were subjected to a tracking task on a microcomputer CRT while parameters of vocal production as well as heart rate were measured. Findings confirm those of earlier studies that increases in fundamental frequency, amplitude, and speech rate are found in speakers involved in extreme levels of stress. In addition, it was found that the same changes appear to occur in a regular fashion within a more subtle level of stress that may be characteristic, for example, of routine flying situations. None of the individual speech measures performed as robustly as did heart rate

Symmetric Composite Laminate Stress Analysis

It is demonstrated that COSMIC/NASTRAN may be used to analyze plate and shell structures made of symmetric composite laminates. Although general composite laminates cannot be analyzed using NASTRAN, the theoretical development presented herein indicates that the integrated constitutive laws of a symmetric composite laminate resemble those of a homogeneous anisotropic plate, which can be analyzed using NASTRAN. A detailed analysis procedure is presented, as well as an illustrative example

A stress free model for residual stress assessment using thermoelastic stress analysis

Thermoelastic Stress Analysis (TSA) has been proposed as a method of obtaining residual stresses. The results of a preliminary study demonstrated that when Al-2024 plate containing holes that were plastically deformed by cold expansion process to 2% and 4% strain the thermoelastic response in the material around the hole was different to that obtained from a plate that had not experienced any plastic cold expansion (i.e. a reference specimen). This observation provides an opportunity for obtaining residual stresses based on TSA data. In many applications a reference specimen (i.e. residual stress free specimen) may not be available for comparison, so a synthetic, digital bitmap has been proposed as an alternative. An elastic finite element model is created using commercially available software Abaqus/Standard and the resultant stress field is extracted. The simulated stress field from the model is mapped onto a grid that matches the TSA pixel data from a physical reference specimen. This stress field is then converted to a ?T/T field that can be compared to the full-field TSA data. When the reference experimental data is subtracted from the, bitmap dataset the resultant ?T/T field is approximately zero. Further work proposes replacing the experimental reference data with that from specimens that have undergone cold expansion with the aim of revealing the regions affected by residual stress through a departure from zero in the resultant stress field. The paper demonstrates the first steps necessary for deriving the residual stresses from a general specimen using TSA

Analysis of Box Culvert to Reduce Stress Values

At the time of construction of roads, highways a structure is placed (commonly used) to transfer the traffic, rain water, drainage from one side to another of the road is called a culvert placed beneath the road. Due to the structural use, multiple loads are placed on the box causing various types of stress which occurs on it. The paper tries to reduce the stress occurred in the box by flaring the box partially

In plane stress analysis

An investigation of the blowing up of UK numerical results for the inplane stress calculations for silicon ribbon is presented. The inplane stress that exists in a thin plate is governed by two general equations of equilibrium and compatibility

Holographic stress analysis

Device for nondestructive testing of soldered joints correlates stress with load to predict printed circuit board lifetime

Effects of duration of water stress at different growth stages on growth and yield of soybeans (Glycine max (L) Merrill) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agriculture in Plant Science at Massey University

Four soybean cultivars (viz. Evans, Geiso, Maple Arrow and S.J.4) were subjected to water stress at three different reproductive growth stages: i)entire reproductive growth stages (R1 to R7) ii) early reproductive growth stages (R1 to R4) and iii) late reproductive growth (R4 to R7). The experiment was conducted in the climate laboratory at the Plant Physiology Division D.S.I.R. Palmerston North, New Zealand, with 31°/23°c (day/night temperature) 70/90% RH (day/night relative humidity) and 14 hours photoperiod. The growth and development of the soybeans were markedly affected by water stress. Leaf area, final plant length, number of nodes and total plant dry weight from the stress treatments were reduced. Seed yield per plant from the three stress treatments were only 10.7, 49.6, and 24.1% relative to that of control treatment. The response of soybean yield depended on both the timing and the duration of stress in relation to growth stages whilst some other plant characters such as plant length and the number of nodes responded more to the timing rather than the duration of stress. Cultivars with the determinate growth type (viz. Evans and Maple Arrow) were apparently more sensitive to stress at the early phase of reproductive growth (R1 to R4) whilst the indeterminate growth type (viz. Geiso and S.J.4) were more sensitive to water stress at the later phase of reproductive growth (R4 to R7). The number of pods per plant was the most important yield component in determining yield although in Evans and the early stress treatment the average seed weight was the most important component. The rank of cultivars, from low to high sensitivity to water stress is Maple Arrow, Evans, Geiso and S.J.4. S.J.4 also reacted differently from the other three cultivars in many aspects. The drought tolerance test estimated through a measurment of electrolyte leakage from the cells was used and discussed. Two methods of genotype x environment interaction analysis (regression analysis and discriminant analysis) were used. The discriminant analysis had some advantages in the study of GE interaction e.g. it could be done with several characters at once and compared with the regression method it could be used with a much lesser number of cultivars and environments. Key words: Soybeans, water stress, growth stages, yield and yield components, drought tolerance test, GE interaction, discriminant analysis, principal component analysis

Finite element analysis of compressible solids with nonlinear material properties

Finite-element computer program solves for nodal point displacements in an axisymmetric solid. The options in the program include plane stress analysis, axisymmetric solids analysis, nonlinear /plastic/ analysis, and equivalent stress and strain

High temperature stress-strain analysis

The objectives of the high-temperature structures program are threefold: to assist in the development of analytical tools needed to improve design analyses and procedures for the efficient and accurate prediction of the nonlinear structural response of hot-section components; to aid in the calibration, validation, and evaluation of the analytical tools by comparing predictions with experimental data; and to evaluate existing as well as advanced temperature and strain measurement instrumentation. As the analytical tools, test methods, tests, instrumentations, as well as data acquisition, management, and analysis methods are developed and evaluated, a proven, integrated analysis and experiment method will result in a more accurate prediction of the cyclic life of hot section components

Electronic stress tensor analysis of hydrogenated palladium clusters

We study the chemical bonds of small palladium clusters Pd_n (n=2-9) saturated by hydrogen atoms using electronic stress tensor. Our calculation includes bond orders which are recently proposed based on the stress tensor. It is shown that our bond orders can classify the different types of chemical bonds in those clusters. In particular, we discuss Pd-H bonds associated with the H atoms with high coordination numbers and the difference of H-H bonds in the different Pd clusters from viewpoint of the electronic stress tensor. The notion of "pseudo-spindle structure" is proposed as the region between two atoms where the largest eigenvalue of the electronic stress tensor is negative and corresponding eigenvectors forming a pattern which connects them.Comment: 22 pages, 13 figures, published online, Theoretical Chemistry Account