Search results for " Satu"
showing 10 items of 360 documents
The one loop gluon emission light cone wave function
2017
Light cone perturbation theory has become an essential tool to calculate cross sections for various small-$x$ dilute-dense processes such as deep inelastic scattering and forward proton-proton and proton-nucleus collisions. Here we set out to do one loop calculations in an explicit helicity basis in the four dimensional helicity scheme. As a first process we calculate light cone wave function for one gluon emission to one-loop order in Hamiltonian perturbation theory on the light front. We regulate ultraviolet divergences with transverse dimensional regularization and soft divergences with using a cut-off on longitudinal momentum. We show that when all the renormalization constants are comb…
Japānas krūmcidonijas Chaenomeles japonica šūnu suspensijas kultūras raksturošana pielietošanai biotehnoloģijā
2021
Darba mērķis bija raksturot Japānas krūmcidonijas Chaenomeles japonica suspensiju kultūru un izvērtēt tās pielietojumu biotehnoloģijā. Darbā no C. japonica kallusu kultūrām iegūtas suspensiju kultūras, veikta šūnu vizualizācija ar fluorescences mikroskopijas metodēm. Konstruēta augšanas līkne, no kuras ievākti paraugi antiradikālās aktivitātes, kopējo fenolu un antocianīnu satura noteikšanai. Lielāko fenolu savienojumu koncentrāciju un augstāko antiradikālo un antimikrobiālo aktivitāti uzrādīja stacionārās fāzes paraugi. Lielāko antocianīnu saturu uzrādīja astotās dienas paraugs. Šūnas suspensijās agregātos bija lielākoties dediferencējušās.
Impact of temperature on obstructive sleep apnoea in three different climate zones of Europe: Data from the European Sleep Apnoea Database (ESADA)
2021
Recent studies indicate that ambient temperature may modulate obstructive sleep apnoea (OSA) severity. However, study results are contradictory warranting more investigation in this field. We analysed 19,293 patients of the European Sleep Apnoea Database (ESADA) cohort with restriction to the three predominant climate zones according to the Koppen-Geiger climate classification: Cfb (warm temperature, fully humid, warm summer), Csa (warm temperature, summer dry, hot summer), and Dfb (snow, fully humid, warm summer). Average outside temperature values were obtained and several hierarchical regression analyses were performed to investigate the impact of temperature on the apnea-hypopnea index …
EXPLANATORY FACTORS OF MARKET POWER IN THE BANKING SYSTEM
2007
The aim of the study is to analyse the explanatory factors of market power in the banking system. Using as laboratory the Spanish banking system in the period 1986–2002, results show an increase of market power from the mid-1990s. Of the set of variables that the model posits as explaining market power, those with the greatest explanatory power are size, efficiency and specialization; concentration is not significant. This last result shows the limitations of the approaches, studies and decision-making rules of economic policy that uses market concentration as a proxy for the degree of competition.
Enhanced Mathematical Modelling of Interior Permanent Magnet Synchronous Machine Considering Saturation, Cross-Coupling and Spatial Harmonics effects
2020
The Interior Permanent Magnet Synchronous machine (IPMSM) conventional mathematical model is generally employed to investigate and simulate the IPMSM control and drive system behaviour. However, magnetic nonlinearities and spatial harmonics have a substantial influence on the IPMSM electromagnetic behaviour and performances. In order to simulate the IPMSM real electromagnetic behaviour, this paper describes an enhanced mathematical model that takes into account the saturation, cross-coupling and spatial harmonics effects. This model has been implemented in Matlab®/Simulink environment where the electric and magnetic parameters are derived from FEA investigations and implemented by the use o…
A Measurement System for Power Inductors in Non-Linear Operating Conditions
2021
The exploitation of power inductors in switching converters outside the linear region requires detailed information on the magnetization curve that often is not included among those usually available on their datasheets. This paper proposes an automatic system in which the inductor is characterized in real operating conditions taking into account also the core temperature. It is based on a switching converter suitably controlled by a virtual instrument. The system was tested by retrieving the inductance vs current curves of two commercial inductors for core temperatures up to 105°C, showing the different behaviors of the magnetization curves. Results are coherent with data given by manufact…
Functional consequences of prey acclimation to ocean acidification for the prey and its predator
2016
Ocean acidification is the suite of chemical changes to the carbonate system of seawater as a consequence of anthropogenic carbon dioxide (CO2) emissions. Despite a growing body of evidences demonstrating the negative effects of ocean acidification on marine species, the consequences at the ecosystem level are still unclear. One factor limiting our ability to upscale from species to ecosystem is the poor mechanistic understanding of the functional consequences of the observed effects on organisms. This is particularly true in the context of species interactions. The aim of this work was to investigate the functional consequence of the exposure of a prey (the mussel Brachidontes pharaonis) t…
Approfondimenti e sviluppi sulla misura in campo e in laboratorio della conducibilità idraulica del suolo
2010
Robust fault-tolerant H∞ control of active suspension systems with finite-frequency constraint
2015
Abstract In this paper, the robust fault-tolerant (FT) H ∞ control problem of active suspension systems with finite-frequency constraint is investigated. A full-car model is employed in the controller design such that the heave, pitch and roll motions can be simultaneously controlled. Both the actuator faults and external disturbances are considered in the controller synthesis. As the human body is more sensitive to the vertical vibration in 4–8 Hz, robust H ∞ control with this finite-frequency constraint is designed. Other performances such as suspension deflection and actuator saturation are also considered. As some of the states such as the sprung mass pitch and roll angles are hard to m…
Robust l2-gain control for 2D nonlinear stochastic systems with time-varying delays and actuator saturation
2013
Abstract This paper is concerned with the problems of stability analysis and l2-gain control for a class of two-dimensional (2D) nonlinear stochastic systems with time-varying delays and actuator saturation. Firstly, a convex hull representation is used to describe the saturation behavior, and a sufficient condition for the existence of mean-square exponential stability of the considered system is derived. Then, a state feedback controller which guarantees the resulting closed-loop system to be mean-square exponentially stable with l2-gain performance is proposed, and an optimization procedure to maximize the estimation of domain of attraction is also given. All the obtained results are for…