Search results for " Saturation"
showing 10 items of 177 documents
Non-Linear Inductors Characterization in Real Operating Conditions for Power Density Optimization in SMPS
2021
The exploitation of power inductors outside their linear region in switching converters can be achieved by raising the current until a decreasing of the inductance can be noticed. It allows using a smaller magnetic core increasing the power density of the converter. On the other hand, a detailed description of the magnetization curve including the temperature is required. Since this information is often not included in the inductor’s datasheets, this paper shows how to identify the behavior of an inductor when it is operated up to saturation and its temperature rises. In order to characterize the inductor in real operating conditions, a dedicated measurement rig has been developed. It consi…
Volume change characteristics of fine-grained soils due to sequential thermo-mechanical stresses
2019
Know-how of volume change characteristics, VCC, of the fine-grained soils, exposed to thermal stresses, is essential for design of various thermo-active structures. These stresses are known to induce excess pore-water pressure, Δu θ , in the saturated state of such soils, which in turn affects their compression and shear strength characteristics. In this context, through several experimental studies, the effect of thermo-mechanical stress-path, the over-consolidation ratio (OCR) and degree of saturation on VCC (viz., thermally induced volumetric strain, ε vθ , compression and re-compression indices, c c and c r ) of the fine-grained soils has been demonstrated by earlier researchers. Howeve…
Impact of Various Thermal Doses on the Oxygenation and Blood Flow in Malignant Tumors Upon Localized Hyperthermia
1984
Hyperthermia exhibits various direct cytocidal effects (Dickson, 1977; Overgaard, 1977; Suit, 1977). During heat treatment in vivo, several indirect mechanisms enhance the direct cell-killing capacity of hyperthermia. Therefore, the effective use of hyperthermia can overcome some of the well-known problems involved in modern radiation therapy at least in some malignant tumors.
Structure of longitudinal chromomagnetic fields in high energy collisions
2014
We compute expectation values of spatial Wilson loops in the forward light cone of high-energy collisions. We consider ensembles of gauge field configurations generated from a classical Gaussian effective action as well as solutions of high-energy renormalization group evolution with fixed and running coupling. The initial fields correspond to a color field condensate exhibiting domain-like structure over distance scales of order the saturation scale. At later times universal scaling emerges at large distances for all ensembles, with a nontrivial critical exponent. Finally, we compare the results for the Wilson loop to the two-point correlator of magnetic fields.
Two relaxation times and thermal nonlinear waves along wires with lateral heat exchange
2021
Abstract We propose a model for studying several nonlinear waves for heat transport along a cylindrical system with lateral non-linear heat transfer to the environment. We consider relaxational equations, each with its own relaxation time, for longitudinal heat transfer and for lateral heat transfer across the wall. We consider two kinds of nonlinear lateral heat transport: radiative heat transport, and flux-limited heat transport. This work generalizes our previous studies in which the relaxation time for the lateral heat transfer was considered equal to that of the longitudinal heat flux. We explore the influence of both relaxation times on the propagation speed of linear and nonlinear wa…
Changement d’usage réglementaire du sol. Comment sélectionner les zones à préserver ?
2014
Agrosup SPE EA EcolDur CT4 EJ3; National audience
Using natural analogues to investigate the effects of climate change and ocean acidification on Northern ecosystems
2018
AbstractNorthern oceans are in a state of rapid transition. Still, our knowledge of the likely effects of climate change and ocean acidification on key species in the food web, functionally important habitats and the structure of Arctic and sub-Arctic ecosystems is limited and based mainly on short-term laboratory studies on single species. This review discusses how tropical and temperate natural analogues of carbonate chemistry drivers, such as CO2 vents, have been used to further our knowledge of the sensitivity of biological systems to predicted climate change, and thus assess the capacity of different species to show long-term acclimation and adaptation to elevated levels of pCO2. Natur…
Hyperspectral evaluation of skin blood oxygen saturation at baseline and during arterial occlusion
2018
Skin capillary blood oxygen saturation is a clinically important diagnostic parameter, which provides valuable information for timely treatment of pathological conditions e.g. sepsis, hypoxemia or decompression illness. Hyperspectral imaging is non-invasive optical techniques with high clinical potential, however its use for skin blood oxygen saturation detection is still challenging, therefore in the present study, a method for in-vivo manipulation of skin oxygen saturation was developed, and reliability of the method evaluated by means of hyperspectral imaging in detection of oxygen saturation. In order to produce alterations of skin capillary blood parameters and oxygen saturation, the p…
Effect of rapid maxillary expansion on sleep apnea-hypopnea syndrome in growing patients. A meta-analysis.
2019
Background Changes produced in the upper airway after rapid maxillary expansion makes this procedure a therapeutic option for treating sleep apnea-hypopnea syndrome (SAHS) in children. The objective of this systematic review and meta-analysis was to analyze the evidence available for the effects of rapid maxillary expansion (RME) on SAHS, analyzing changes produced in oximetric variables: apnea-hypopnea index (AHI); oxygen saturation (SO2); sleep efficiency (SE), total sleep time (TST), percentage of rapid eye movement (REM) phase; and arousal index (AI). Material and Methods An electronic search was conducted in the PubMed, Scopus, Embase, and Cochrane databases, and in grey literature (Op…
Signal processing procedures for the evaluation of the cardiovascular effects in the obstructive sleep apnea syndrome
2002
A new index, the cross-power index (CPI), is proposed to quantify the severity of obstructive sleep apnea syndrome (OSAS) in terms of its cardiovascular effects. On the basis of the influences that recurring drops in oxygen saturation have on systolic blood pressure variability of OSAS patients, CPI is defined as the integral of the cross-spectrum modulus between systolic blood pressure and oxygen saturation. In a test group of 22 subjects, CPI correctly identified all 15 OSAS patients included in the pool. Moreover, evaluation of CPI in six OSAS patients sleeping with and without a CPAP (continuous positive airway pressure) device demonstrated that CPAP treatment substantially reduced the …