Effects of grain moisture, drying methods, and variety on breakage susceptibility of shelled corn as measured by the Wisconsin Breakage Tester

Breakage susceptibility has become an important quality characteristic of corn traded in the international market. Centrifugal impacters like the Wisconsin Breakage Tester may be used for rapid determination of breakage characteristics of different corn lots. However, the high dependence of breakage on moisture content necessitates testing at or correcting to a common moisture level;The objective of this study was to quantify the effects of grain moisture, drying methods, and variety on breakage susceptibility values of shelled corn and also to derive a generalized moisture correction equation to allow use of testers like the Wisconsin Breakage Tester in grain market channels;Breakage susceptibility of 576 samples was measured by a Wisconsin Breakage Tester. Breakage susceptibility increased by 40% (compounded) per percentage point decrease in grain moisture content. Heated air drying at 93.3(DEGREES)C increased breakage susceptibility of corn by 2 to 3 times. Breakage susceptibility of heated air dried corn increased by 0.35 percentage point per percent increase in harvest moisture within the range of 23% to 32%. Harvest moisture did not affect samples slow-dried by room temperature air;Breakage susceptibility of corn dried by heated air was also found to increase by 0.74 percentage point for every percent point decrease in the dry down moisture level from 18% to 12%;If dried by heated air, Pioneer 3780 was the least susceptible to breakage, while Pioneer 3720 was most susceptible to breakage. Varietal difference in breakage susceptibility was not observed if the corn was slow-dried by room air;A generalized moisture adjustment equation was derived for compensating the variation in breakage values resulting from changes in grain moisture;Breakage susceptibility values were not correlated with sample test weight or particle size of ground corn

Microstructural evolution during remelting of laser surface alloyed hyper-monotectic Al-Bi alloy

The present investigation explores the possibility of synthesizing a two-phase microstructure consisting of a fine dispersion of bismuth particles in an aluminium matrix using the laser surface alloying technique. The possibility of controlling the size distribution of bismuth particles by subsequent remelting is also investigated. The microstructural analysis of the surface alloyed samples shows that the average size of the bismuth particles reduces with increase in laser scan speed. In order to understand the factors that determine the nature of the size distribution of the particles, a detailed model is developed. The model incorporates heat and fluid flow induced by the laser to arrive at the evolution of the temperature and velocity of the melt in three dimensions. Using these as inputs, a kinetic analysis of the nucleation, growth and coarsening induced by collision-controlled coalescence of the bismuth particles from the melt is carried out. Comparison with the experiments indicates that coalescence due to convection plays an important role in the evolution of the size distribution of bismuth particles

Spektroskopska mjerenja prijelaza D2 Rb u ovisnosti o temperaturi i snazi sa i bez Dopplerovog efekta

An external-cavity diode-laser spectrometer has been set up for high-resolution measurement of line shapes of the RbD2 transitions. Temperature-dependent fine-structure measurements are carried out in a free-running temperature condition by using frequency ramps for repetitive current tuning over a region of 17 GHz, encompassing all of the four Doppler broadened transitions of the two isotopes in an almost collision-free region. The Doppler broadened widths extracted from temperature-dependent line shapes, on least squares fitting to observed data, lead to an estimation of root-means-square velocities of vapour atoms under varying temperature conditions. Saturated-absorption spectroscopic measurements show complete resolution of the hyperfine Lamb dips and crossover resonance dips of one 87RbD2 transition. Data recorded from power-dependent measurement of one of unresolved 85RbD2 transitions are analyzed to obtain the saturation parameter and power broadening coefficient. The linewidths of different fully resolved Lamb dips of the hyperfine and crossover-resonance components are not the same, suggesting differences in their natural linewidths.Pomoću diodnog lasera s vanjskim rezonatorom načinili smo mjerenja oblika linija prijelaza D2 Rb. Mjerenja temperaturne ovisnosti fine strukture izveli smo u uvjetima slobodno promjenljive temperature, upotrebom frekventne rampe za ponavljanje struje, podešene za područje 17 GHz koje obuhvaća sva četiri Dopplerovim efektom proširena prijelaza dvaju izotopa Rb u uvjetima gotovo bez sudara. Širenje linija Dopplerovim efektom u ovisnosti o temperaturi, utvrđeno metodom najmanjih kvadrata, daje korijene iz srednjih kvadrata brzina atoma u parama. Spektroskopska mjerenja sa zasićenom apsorpcijom pokazuju potpuno razlučivanje hiperfinih Lambovih i preskočnih rezonantnih minimuma prijelaza D2 87Rb. Podatke iz mjerenja ovisnosti o snazi za nerazlučeni prijelaz D2 85Rb smo analizirali radi dobivanja parametara zasićenja i koeficijenta širenja sa snagom. Širine potpuno razlučenih linija hiperfinih Lambovih i preskočnih rezonantnih minimuma nisu jednake, što ukazuje na različitost njihovih prirodnih širina

Characterization of a continuous CO2 laser-welded Fe-Cu dissimilar couple

Continuous CO2 laser welding of an Fe-Cu dissimilar couple in a butt-weld geometry at different process conditions is studied. The process conditions are varied to identify and characterize the microstructural features that are independent of the welding mode. The study presents a characterization of the microstructure and mechanical properties of the welds. Detailed microstructural analysis of the weld/base-metal interface shows features that are different on the two sides of the weld. The iron side can grow into the weld with a local change in length scale, whereas the interface on the copper side indicates a barrier to growth. The interface is jagged, and a banded microstructure consisting of iron-rich layers could be observed next to the weld/Cu interface. The observations suggest that solidification initiates inside the melt, where iron and copper are mixed due to convective flow. The transmission electron microscopy (TEM) of the weld region also indicates the occasional presence of droplets of iron and copper. The microstructural observations are rationalized using arguments drawn from a thermodynamic analysis of the Fe-Cu system

Photons from Hadronic Matter at Finite Temperature

Temperature dependence of hadronic decay widths and masses are studied within the framework of an effective Lagrangian approach. At finite temperature the hadronic masses do not seem to follow a universal scaling law. Considering an exhaustive set of hadronic reactions and vector meson decays we have estimated the photon spectrum emitted from hot hadronic matter taking into account medium effects through thermal loop corrections on the hadronic decay widths and masses. An enhancement in photon emission rate is obtained when we use the in-medium masses of vector mesons in our calculations. It is observed that the effect of $\rho$ decay width on the photon spectra is negligible.Comment: changed content, added references and figures.(30 pages, Figures included). To appear in Nuclear Physics

A New Approach to Compute the Porosity and Surface Roughness of Porous Coated Capillary-Assisted Low Pressure Evaporators

The fundamental characteristics of metal coatings that influence heat transfer are porosity and surface roughness. It is a challenge to analyze the porosity and surface roughness due to the inadequate amount of copper per coated area. In this study, a new approach to non-invasively determine the porosity of metal films utilizing a helium pycnometer and computed micro-tomography (CMT) is presented. Furthermore, a telescope-goniometer is used to measure the surface roughness. Experiments are conducted on four varieties of thin film samples coated with copper powder using wire flame and plasma thermal spray coating methods. The porosities of the thin films were determined to be between 39 and 43%. The thermal spray coating increased the hydrophobicity of the surface and the plasma coating created super-hydrophobic surfaces. The new approach establishes that the porosity of thin films can be non-invasively determined and may also be applied to a wide variety of coated surfaces

Omega meson as a chronometer and thermometer in hot-dense hadronic matter

Changes in the properties of the vector mesons in hot and dense hadronic matter, as produced in heavy ion collisions, lead to the intriguing possibility of the opening of the decay channel \omega \ra \rho \pi, for the omega meson, which is impossible in free space. This along with the channel \omega \pi \ra \pi \pi would result in a decrease in its effective life-time enabling it to decay within the hot zone and act as a chronometer in contradiction to the commonly held opinion and would have implications vis a vis determination of the size of the region through pion interferometry. A new peak and a radically altered shape of the low invariant mass dilepton spectra appears due to different shift in the masses of $\rho$ and $\omega$ mesons. The Walecka model is used for the underlying calculation for the sake of illustration.Comment: To appear in Phys. ReV.

Unstable particles in matter at a finite temperature: the rho and omega mesons

Unstable particles (such as the vector mesons) have an important role to play in low mass dilepton production resulting from heavy ion collisions and this has been a subject of several investigations. Yet subtleties, such as the implications of the generalization of the Breit-Wigner formula for nonzero temperature and density, e.g. the question of collisional broadening, the role of Bose enhancement, etc., the possibility of the kinematic opening (or closing) of decay channels due to environmental effects, the problem of double counting through resonant and direct contributions, are often given insufficient emphasis. The present study attempts to point out these features using the rho and omega mesons as illustrative examples. The difference between the two versions of the Vector Meson Dominance Model in the present context is also presented. Effects of non-zero temperature and density, through vector meson masses and decay widths, on dilepton spectra are studied, for concreteness within the framework of a Walecka-type model, though most of the basic issues highlighted apply to other scenarios as well.Comment: text and figures modifie