Search results for "Expansion"
showing 10 items of 630 documents
Vibrational properties of ZnTe at high pressures
2002
Raman spectra of ZnTe were measured under hydrostatic pressures up to 15 GPa at T = 300 K. Results for the frequencies of first- and second-order Raman features of the zincblende phase (0-9.5 GPa) are used to set up a rigid-ion model of the phonon dispersion relations under pressure. Calculated phonon densities of states, mode Gruneisen parameters and the thermal expansion coefficient as a function of pressure are discussed. The effect of pressure on the widths and intensities of Raman spectral features is considered. Raman spectra of high-pressure phases of ZnTe are reported. These spectra indicate the possible existence of a new phase near 13 GPa, intermediate between the cinnabar and ort…
Testing theories of Gravity and Supergravity with inflation and observations of the cosmic microwave background
2016
Many extensions of Einstein's theory of gravity have been studied and proposed with various motivations like the quest for a quantum theory of gravity to extensions of anomalies in observations at the solar system, galactic and cosmological scales. These extensions include adding higher powers of Ricci curvature $R$, coupling the Ricci curvature with scalar fields and generalized functions of $R$. In addition when viewed from the perspective of Supergravity (SUGRA) many of these theories may originate from the same SUGRA theory interpreted in different frames. SUGRA therefore serves as a good framework for organizing and generalizing theories of gravity beyond General Relativity. All these …
Analysis of Early Host Responses for Asymptomatic Disease Detection and Management of Specialty Crops
2010
The rapid and unabated spread of vector-borne diseases within US specialty crops threatens our agriculture, our economy, and the livelihood of growers and farm workers. Early detection of vector-borne pathogens is an essential step for the accurate surveillance and management of vector-borne diseases of specialty crops. Currently, we lack the tools that would detect the infectious agent at early (primary) stages of infection with a high degree of sensitivity and specificity. In this paper, we outline a strategy for developing an integrated suite of platform technologies to enable rapid, early disease detection and diagnosis of huanglongbing (HLB), the most destructive citrus disease. The re…
X-ray investigation and discussion of the magnetostriction of Gd3T(T= Ni, Rh, Irx) single crystals
2000
The variations of the lattice parameters of Gd3T(T= Ni, Rh, Irx) single crystals with temperature were measured in the range 10–300 K. The compounds with Ni and Rh crystallize in the orthorhombic space groupPnma, but the compound with Ir crystallizes as Gd5Ir2in the monoclinic space groupA2/a. The three compounds exhibit an anomalous anisotropic spontaneous magnetostriction below the magnetic ordering temperature.
“Henry Wadsworth Longfellow’s Evangeline: A Tale of Acadie and the Ambiguous Afterlife of the History of the Acadians”
2018
Abstract Longfellow’s Evangeline was hailed as a great and distinctively American work when it appeared in 1847, and the poem’s use of North American history was a key element in its favourable reception. This use of history, however, is ambiguous and complex. The epic continues, first of all, in a long tradition of romanticized retellings of the heart-rending story of the Acadians. But the work also engages in a dual-level dialogue with both the mid-eighteenth-century history of the Acadians, who are pitied, without inciting indignation, and the contemporary history of midnineteenth-century America, whose expansionism it both implicitly celebrates and criticizes. Resume Evangeline, le poem…
Residual Stresses Induced by Cold Expansion of Adjacent and Cut-Out Holes
2012
Fatigue life of fastener holes can be enhanced via a cold-expansion process to introduce a compressive residual stress field around the hole edge and to reduce crack growth propagation. Considering that aerospace components contain multiple rows of holes, the present investigation focuses on the evaluation of the three-dimensional residual stress distribution in adjacent cold-expanded (CE) holes. The redistribution of residual stresses caused by a cut introduced between two adjacent holes was also investigated. Finite element (FE) analysis and experimental technique were used to assess the residual stress distribution in a 6082-T6 aluminum plate with two adjacent holes expanded sequentially…
3D-simulation studies of the modified magnetic multipole structure for an electron cyclotron resonance ion source
2004
Experiments have shown that efficient operation of an electron cyclotron resonance ion source requires that the magnetic field fulfills the so-called scaling laws. In most cases the requirements for the radial magnetic field, i.e. the strength of the magnetic multipole are the most difficult to satisfy. This is due to the fact that the multipole is usually produced from permanent magnets, which makes a value of 1.3 T feasible. One possible solution to increase the multipole field is the so-called Modified MultiPole Structure (JYFL-MMPS). This new idea makes it possible to increase the magnetic field at the places where the plasma flux is in contact with the plasma chamber wall. In this arti…
Mitochondrial DNA variation of Drosophila obscura (Diptera: Drosophilidae) across Europe
2022
Drosophila obscura is a common fruit fly that inhabits the temperate forests of Europe. While it is abundant in the north compared to other Drosophila, its density decreases southwards, where it is gradually replaced by other Drosophila species. This study describes variation in the mitochondrial Cyt b gene of D. obscura from several European populations. We observed a large number of haplotypes, together with the structuring of genetic variation. Genetic variation is higher in the west where O1 and related divergent haplotypes dominate. In the east, the O2 haplotype is most frequent, together with haplotypes that recently arose from it. In the central part of the species range, both O1 and…
Simultaneous measurement of temperature and strain in glass fiber/epoxy composites by embedded fiber optic sensors: II. Post-cure testing
2007
In this paper the use of fiber optic sensors embedded into GFRP laminates for structural health monitoring of thermo-mechanical loads is presented. The proposed sensing system, consisting of two coupled fiber Bragg grating (FBG) sensors, allows the simultaneous measurement of both temperature and strain by decoupling the change in reflected wavelength induced by temperature variations from that induced by either mechanical or apparent strain, with significant advantages either for monitoring the composite cure kinetics, as described in the accompanying paper (Part I), or for assessing the structural response to thermo-mechanical loads. Both thermal ramp and mechanical static/dynamic bending…
The Diapause Lipidomes of Three Closely Related Beetle Species Reveal Mechanisms for Tolerating Energetic and Cold Stress in High-Latitude Seasonal E…
2020
During winter insects face energetic stress driven by lack of food, and thermal stress due to sub-optimal and even lethal temperatures. To survive, most insects living in seasonal environments such as high latitudes, enter diapause, a deep resting stage characterized by a cessation of development, metabolic suppression and increased stress tolerance. The current study explores physiological adaptations related to diapause in three beetle species at high latitudes in Europe. From an ecological perspective, the comparison is interesting since one species (Leptinotarsa decemlineata) is an invasive pest that has recently expanded its range into northern Europe, where a retardation in range expa…