On the Application of Deformation Kinetics to Nonlinear Constitutive Relations at Higher Temperatures

A single phenomenological constitutive equation is derived theoretically from first principles and applied to aluminum, tin and lead. The theory is based on deformation kinetics of steady creep in which the fundamental mechanism is atomic transport over potential barriers whose conformation is distorted by the application of a stress field. The form of the functional dependence of barrier distortion and stress over the entire temperature range is found to be a sigmoidal curve which tends to straight lines of a unit slope in the small and high stress regions. With this form of barrier distortion, the constitutive equation prediction the steady creep behavior of aluminum, tin and lead over a wide range of temperature and stress

An Investigation on the Larval Habitat of Five Species of Tree-Hole Breeding Mosquitoes (Diptera: Culicidae)

A two-year study on the larval habitat of five species of tree-hole breeding mosquitoes was conducted in the vicinity of Bowling Green, Wood County, Ohio. Ninety-eight tree holes containing mosquito larvae were studied. Larval collections (27,741 specimens) were comprised of Aedes rriseriarus (90.8%), Orrhopodomyia signifera (3.3%), Aedes hendersoni (3.2%), Anopheles barberi (2.7%) and Orrhopodomyia alba (\u3c 0.1%). Chemical parameters (BOD, tannin-lignin, pH, and conductivity) of different tree holes were evaluated. Although different tree-hole species were commonly found in association with one another at breeding sites, ecological differences between species were found in spatial, trophic, and temporal niche dimensions

Some Recent Developments in the Endochronic Theory with Application to Cyclic Histories

Constitutive equations with only two easily determined material constants predict the stress (strain) response of normalized mild steel to a variety of general strain (stress) histories, without a need for special unloading-reloading rules. The equations are derived from the endochronic theory of plasticity of isotropic materials with an intrinsic time scale defined in the plastic strain space. Agreement between theoretical predictions and experiments are are excellent quantitatively in cases of various uniaxial constant amplitude histories, variable uniaxial strain amplitude histories and cyclic relaxation. The cyclic ratcheting phenomenon is predicted by the present theory

Xantusia henshawi

Number of Pages: 2Integrative BiologyGeological Science

Contactless pellet fabrication

A small object is coated by holding it in the pressure well of an acoustic standing wave pattern, and then applying a mist of liquid coating material at low velocity into the pressure well. The pressure gradient within the well forces the mist particles to be pushed against the object. A lower frequency acoustic wave also can be applied to the coated object, to vibrate it so as to evenly distribute the coated material. The same lower frequency vibrations can be applied to an object in the shape of a hollow sphere, to center the inner and outer surfaces of the sphere while it remains suspended