An Existence Theorem for Evolution Inclusions Involving Opposite Monotonicities

AbstractIn this paper we examine evolution inclusions of the subdifferential type with the set-valued perturbation being nonconvex valued and dissipative. Under certain generally mild hypotheses on the data, we prove the existence of a strong global solution, extending earlier analogous results by M. Ôtani and A. Cellina-V. Staicu. An example of a distributed parameter system is also presented in detail

Theoretical and numerical studies of wave-packet propagation in tokamak plasmas

Theoretical and numerical studies of wave-packet propagation are presented to analyze the time varying 2D mode structures of electrostatic fluctuations in tokamak plasmas, using general flux coordinates. Instead of solving the 2D wave equations directly, the solution of the initial value problem is used to obtain the 2D mode structure, following the propagation of wave-packets generated by a source and reconstructing the time varying field. As application, the 2D WKB method is applied to investigate the shaping effects (elongation and triangularity) of tokamak geometry on the lower hybrid wave propagation and absorbtion. Meanwhile, the Mode Structure Decomposition (MSD) method is used to handle the boundary conditions and simplify the 2D problem to two nested 1D problems. The MSD method is related to that discussed earlier by Zonca and Chen [Phys. Fluids B 5, 3668 (1993)], and reduces to the well-known "ballooning formalism" [J. W. Connor, R. J. Hastie, and J. B. Taylor, Phys. Rev. Lett. 40, 396 (1978)], when spatial scale separation applies. This method is used to investigate the time varying 2D electrostatic ITG mode structure with a mixed WKB-full-wave technique. The time varying field pattern is reconstructed and the time asymptotic structure of the wave-packet propagation gives the 2D eigenmode and the corresponding eigenvalue. As a general approach to investigate 2D mode structures in tokamak plasmas, our method also applies for electromagnetic waves with general source/sink terms, either by an internal/external antenna or nonlinear wave interaction with zonal structures.Comment: 24 pages, 14 figure

Il customer value nelle imprese calzaturiere: competere creando valore per il cliente

Le imprese si trovano oggi a competere in un mercato caratterizzato dalla richiesta di un servizio sempre migliore, a costi competitivi. Per fare questo \ue8 necessario gestire in modo efficiente ed efficace le relazioni tra clienti e fornitori lungo la supply chain, al fine di conseguire contestualmente gli obiettivi - tendenzialmente antitetici - della flessibilit\ue0 produttiva e dell\u2019efficienza nella gestione dei costi, migliorando il servizio al cliente (Goldsby et al., 2006). Inoltre, la situazione economica attuale sta sempre pi\uf9 stimolando le imprese a rivedere il loro modello di business; in particolare, i cambiamenti repentini del mercato e della competizione stanno modificando notevolmente le priorit\ue0 e le pratiche manageriali costringendo a poco a poco le imprese a ridefinire le aree di business, nonch\ue9 le scelte strategiche ed operative con l\u2019obiettivo finale di recuperare efficienza e migliorare la soddisfazione del cliente. Analogamente ad altri settori industriali, anche il comparto calzaturiero \ue8 stato caratterizzato da rilevanti trasformazioni inerenti la domanda, l\u2019offerta e la distribuzione; per quanto concerne la domanda, si riscontra la presenza di un consumatore sempre pi\uf9 consapevole che attua comportamenti differenziati e per il quale diventa sempre pi\uf9 rilevante il processo \u201cesperienziale\u201d di acquisto e manifesta una rinnovata attenzione al prezzo (Gregori et alii, 2009). Riguardo al sistema competitivo, si rileva un incremento della concorrenza internazionale, con la nascita di nuove imprese nell\u2019est europeo e nel sud est asiatico. Sempre per quanto concerne le trasformazioni intercorse nel sistema competitivo \ue8 possibile evidenziare un profondo processo di trasformazione le cui dinamiche sono solo in parte in linea con quanto riscontrato in altri comparti del fashion (SDA Bocconi, Novembre 2007). In riferimento alla distribuzione si rileva una certa tensione ad un maggiore \u201ccontrollo\u201d dei canali in alcuni casi mediante la scelta di canali diretti (punti di vendita monomarca) o adottando la formula del franchising (Aiello e Guercini, 2009), sviluppando accordi di distribuzione (soprattutto in alcuni paesi esteri), trasformando reti di vendita indirette in dirette (Gregori et alii, 2009). In questo quadro di riferimento \ue8 importante conoscere le modalit\ue0 mediante le quali l\u2019impresa calzaturiera pu\uf2 incrementare la sua capacit\ue0 di competere creando \u201cvalore per il cliente\u201d business (retailer o altro distributore) anche migliorando la gestione dei processi erroneamente considerati \u201cminori\u201d e che possono costituire, al contrario, un notevole elemento di differenziazione

Thermal Transient Measurements of an Ultra-Low-Power MOX Sensor

This paper describes a system for the simultaneous dynamic control and thermal characterization of the heating of an Ultra Low Power (ULP) micromachined sensor. A Pulse Width Modulated (PWM) powering system has been realized using a microcontroller to characterize the thermal behavior of a device. Objectives of the research were to analyze the relation between the time period and duty cycle of the PWM signal and the operating temperature of such ULP micromachined systems, to observe the thermal time constants of the device during the heating phase and to measure the total thermal conductance. Constant target heater resistance experiments highlighted that an approximately constant heater temperature at regime can only be obtained if the time period of the heating signal is smaller than 50 s. Constant power experiments show quantitatively a thermal time constant that decreases during heating in a range from 2.3 ms to 2 ms as a function of an increasing temperature rise between the ambient and the operating temperature. Moreover, we calculated the total thermal conductance. Finally, repeatability of experimental results was assessed by guaranteeing the standard deviation of the controlled temperature which was within C in worst case conditions

Melatonin, Immune Function and Aging

Aging is associated with a decline in immune function (immunosenescence), a situation known to correlate with increased incidence of cancer, infectious and degenerative diseases. Innate, cellular and humoral immunity all exhibit increased deterioration with age. A decrease in functional competence of individual natural killer (NK) cells is found with advancing age. Macrophages and granulocytes show functional decline in aging as evidenced by their diminished phagocytic activity and impairment of superoxide generation. There is also marked shift in cytokine profile as age advances, e.g., CD3+ and CD4+ cells decline in number whereas CD8+ cells increase in elderly individuals. A decline in organ specific antibodies occurs causing reduced humoral responsiveness. Circulating melatonin decreases with age and in recent years much interest has been focused on its immunomodulatory effect. Melatonin stimulates the production of progenitor cells for granulocytes-macrophages. It also stimulates the production of NK cells and CD4+ cells and inhibits CD8+ cells. The production and release of various cytokines from NK cells and T-helper lymphocytes also are enhanced by melatonin. Melatonin presumably regulates immune function by acting on the immune-opioid network, by affecting G protein-cAMP signal pathway and by regulating intracellular glutathione levels. Melatonin has the potential therapeutic value to enhance immune function in aged individuals and in patients in an immunocompromised state

A study of MHD feedback stabilization in tokamaks with lower hybrid waves

Lower Hybrid Current Drive (LHCD) has been successfully employed in current profile control experiments and can be utilized to prevent MHD instabilities by tailoring the profile. Similarly, theory has shown that LHCD can be very effective in stabilizing MHD instabilities by feedback techniques: this experiment has not been tried yet. This paper addresses some of the practical aspects of such an experiment