Occurrence Of Different Stages Research Articles

Thermal Requirements and Population Viability of Chrysodeixis includens (Lepidoptera: Noctuidae).

Development, mortality, fecundity, and longevity of soybean looper Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae, Plusiinae) were examined at six constant temperatures (18, 22, 25, 28, 32, and 36∘C) under laboratory conditions. This set range comprises temperatures observed at soybean- and cotton-producing regions during the growing season. Complete development from egg to adult was observed from 18 to 32∘C. Linear and nonlinear models were fitted to the data to estimate thermal constants and bioclimatic thresholds. Although the development of immature stages of C. includens can be expected across broader temperature ranges, this species is meant to complete the whole cycle and recover from low densities between 19.7 and 30.0∘C. The best fitness is achieved at 25.4∘C. The results can be used to parameterize phenological or mathematical models to forecast the occurrence of different stages of C. includens in the field and help optimize the efforts to control this insect-pest.

Influence of annealing temperature and electrical conductivity of α-Fe2O3 nanoparticles for Schottky barrier diode

The microwave irradiation route is adopted for synthesizing hematite nanoparticles. The occurrence of different stages in iron oxide nanoparticles due to annealing temperature is validated from its phase transition. The temperature variation for annealing process is made subsequently in this experiment in steps of 300 °C, 400 °C, 500 °C, 600 °C, 700 °C, 800 °C and 900 °C. The formation and deformation of α-Fe2O3 (hematite) phase is identified from this work. The morphology, crystallinity and consistency in particles size are estimated from XRD, SEM and TEM image. The decrease in particle size is due to phase transformation which is identified from 78 to 24 nm. The specified involvement of thermal stability is tested from TGA analysis which is confirmed from phase transition in the XRD. Change in bandgap energy and respective blue shift for less particle sizes are elucidated from UV-DRS and PL spectra. The elemental presence Fe 2p and O 1s spectra indicates the valence states of Fe3+ and O2− from XPS and the VSM results are confirmed according to the increase in saturation and decrease in coercivity tended towards soft magnetic behaviour due to phase transition. The DC electrical conductivity and activation energy are calculated from I–V studies. The Schottky barrier diode parameters of ideality factor (n), barrier height (Φb) and reverse saturation current (I0) is calculated for both dark and light conditions.

Double-structure effects on the chemo-hydro-mechanical behaviour of a compacted active clay

This work presents an insight into double-structure effects on the coupled chemo-hydro-mechanical behaviour of a compacted active clay. In the first part, selected pore size distribution curves are introduced, to highlight the influence of solute concentration on the evolution of the microstructure of compacted samples. An aggregated structure with dual-pore network is induced by compaction even at relatively high water contents. This structural arrangement is enhanced by salinisation, and has a notable influence on transient volume change behaviour – that is, the occurrence of different stages of swelling upon pore water dilution and higher volume change rates upon salinisation. A coupled chemo-hydro-mechanical model, taking into consideration double-structural features from a chemo-mechanical viewpoint, is described and then used to interpret these behavioural responses and present complementary information on local transient processes. The model is designed to identify an intra-aggregate and an inter-aggregate domain, and assigns different values of hydraulic pressure and osmotic suction to each domain. Distinct constitutive laws for both domains are formulated, and the flow of salt and water between the two domains is accounted for by a physically based mass exchange term. The model is used to simulate salt diffusion tests run in an oedometer at constant vertical stress. Parameters used in the formulation are calibrated based on separate experimental evidence, both through direct test results and through back-analyses of laboratory experiments.

Thermal Desorption States of C[sub 60] Fullerene Molecules in Polymer Matrices

Polymer-C60 fullerene composite coatings are studied using thermal desorption mass spectrometry. It is found that thermal desorption spectra of C60 fullerene molecules can exhibit several resolved peaks (at a specified heating rate) corresponding to thermal desorption states. The relative intensity of the thermal desorption peaks depends on the procedure used for preparing the composite coatings, in particular, on the time of sedimentation of the polymer-fullerene suspension. The occurrence of different stages in thermally stimulated desorption of C60 fullerene molecules is explained by the fact that the fullerene molecules can exist in several phase states characterized by different densities and degrees of ordering in the polymer matrix.

The Petrogenetic Evolution of Lavas from Easter Island and Neighbouring Seamounts, Near-ridge Hotspot Volcanoes in theSE Pacific

Major and trace element, mineralogical and petrographical data are presented for submarine and subaerial lavas from Easter Island and two neighbouring seamounts. The samples can be divided into three groups based on their major element composition and incompatible element enrichment, typified by their (La/Sm)N ratios. Tholeiitic samples with (La/Sm)N of ∼1.2 are comparable with lavas constituting three young volcanic fields closer to the spreading axis. The other two lava series from Easter Island and the two seamounts are transitional to slightly alkaline, one having an intermediate enrichment with (La/Sm)N of 1.5–2, the other being even more enriched [(La/Sm)N ∼2.3]. Large phenocrysts and xenocrysts of olivine and plagioclase in the submarine lavas indicate a crustal reservoir with crystallizing magma. Compared with the relatively mafic submarine samples, the more fractionated lavas on Easter Island suggest the presence of another, more shallow magma chamber. The extreme differentiation of rhyolites and trachytes probably occurred as a result of decreasing magma supply during waning phases of volcano activity. Each volcano of the Easter Hotspot probably evolved through at least two stages. A tholeiitic stage appears to form large volcanoes at depths <1000 m and is succeeded by a transitional group of lavas which can be observed on Easter Island. A third stage with the most enriched lavas may form small eruptive centres on the flanks of older volcanoes or as flank cones on the seafloor. The degree of partial melting decreases from the tholeiitic to the most enriched alkaline series. The occurrence of different stages of volcanism at the Easter Hotspot not only resembles the magmatism of other Pacific hotspots such as Hawaii but also the volcanism of non-plume near-ridge seamounts at the East Pacific Rise. We suggest that the development of each magmatic stage depends on the age of the overlying plate, which determines (1) the amount of depleted mid-ocean ridge material mixed into the magma source and (2) the degree of partial melting.

The Ciliated Brain Duct ofOikopleura dioica(Tunicata, Appendicularia)

Transmission electron microscopy revealed varying morphology of the dorsal part of the duct indicating the occurrence of different stages of activity. In some animals the tip cavity contains an amorphous substance which, at another phase of activity, is released into the surrounding hemocel through interstices in the walls of the tip. A transitional zone separates the dorsal tip from the large ventral part of the duct, where the wall, near the transitional zone, consists of a single layer of thin cells joined by tight junctions. Ventrally, the large ciliated cells lie in two levels near the opening into the buccal cavity. They bear numerous, tightly packed cilia which beat vigorously in living animals. The organization of this part resembles that of protonephridia. An excretory function is suggested for this part of the duct.

REGIONAL ENTERITIS

The condition known as enteritis was first established as an entity by Crohn, Ginzburg and Oppenheimer 1 in 1932. It has been variously referred to since that time as terminal ileitis, ileitis and enteritis. The last term is that most commonly accepted at the present time, for the disease is not confined to the ileum but may involve any portion of the small bowel and even the large bowel. Crohn and his collaborators emphasized the occurrence of different stages or phases of regional enteritis, which they characterized as (1) the acute inflammatory phase, (2) the ulcerative phase, (3) the stenotic phase and (4) the phase of formation of fistulas. The first two might be referred to as acute stages and the last two as chronic. However, an important gross differential feature is the patchy or segmental involvement of the bowel. It should be emphasized that lesions of