Stochastic Modeling and Simulation of Ion Transport through Channels

Ion channels are of major interest and form an area of intensive research in the fields of biophysics and medicine since they control many vital physiological functions. The aim of this work is on one hand to propose a fully stochastic and discrete model describing the main characteristics of a multiple channel system. The movement of the ions is coupled, as usual, with a Poisson equation for the electrical field; we have considered, in addition, the influence of exclusion forces. On the other hand, we have discussed about the nondimensionalization of the stochastic system by using real physical parameters, all supported by numerical simulations. The specific features of both cases of micro- and nanochannels have been taken in due consideration with particular attention to the latter case in order to show that it is necessary to consider a discrete and stochastic model for ions movement inside the channels

Comparative study between LMA supreme with I-gel in anaesthetised adult patient on effectiveness and safety

Background: Supreme laryngeal mask airway (SLMA) and I-gel airway devices are second generation supraglottic airway devices (SAD) and are good alternatives to intubation during surgeries. The study was conducted with the objective to compare two supraglottic airway devices for ease of insertion, number of attempts of insertion, hemodynamic changes, incidence of adverse effects like regurgitation, lip and dental trauma and post-operative sore throat, dysphagia or hoarseness.Methods: This study was conducted at Topiwala National Medical College and BYL Nair hospital, Mumbai. 80 patients of ASA class 1 and 2 with Mallampati grading 1 and 2, between age group of 18-60 years and with BMI 0.05). Postoperatively no significant complications were observed in terms of dental injury, laryngospasm. Complication like sore throat after 1 hour and after 24 hours was comparatively more in I-gel group but difference was not significant at 1 hr (p>0.05). Dysphagia was reported more in SLMA group (8 cases) than I-gel group (1 case) at one hour and the difference was statistically significant (p=0.013).Conclusions: SLMA and I-GEL are better airway management option for patients undergoing short surgical procedures under general anaesthesia

Well-posedness of a reaction-diffusion model with stochastic dynamical boundary conditions

We study the well-posedness of a nonlinear reaction diffusion partial differential equation system on the half-line coupled with a stochastic dynamical boundary condition, a random system arising in the description of the evolution of the chemical reaction of sulphur dioxide with the surface of calcium carbonate stones. The boundary condition is given by a Jacobi process, solution to a Brownian motion-driven stochastic differential equation with a mean reverting drift and a bounded diffusion coefficient. The main result is the global existence and the pathwise uniqueness of mild solutions. The proof relies on a splitting strategy, which allows to deal with the low regularity of the dynamical boundary condition

Development of sustainable ORC applications in the tertiary sector: a case study in the Mediterranean climate

In recent decades, climate change strong advancement has led many countries, especially the most developed ones, to a greater sense of environmental responsibility. On a global, European and national level, adaptation/mitigation strategies and actions aimed at improving energy-environmental sustainability and resilience in the tertiary sectors have been increasingly intensified. In this sector, therefore, plays a fundamental role the integration/introduction of technologies able to operate an efficient conversion of energy, such as indeed Organic Rankine Cycle (ORC) plant, other than renewable energy sources, in order to reduce both energy consumption and pollutant emissions. Within this scenario, the aim of this work is to investigate the potential application of a cogeneration ORC system powered by solar collector and geothermal sources, by evaluating its energy, environmental and economic advantages and limitations. To this purpose a case study involving the coverage of the energy needs of a hotel located in Catania (Southern Italy) has been simulated and analyzed. The outcomes put in evidence the importance of the operative conditions in optimizing the productivity of an ORC plant, especially when associated with renewable energy sources, although at the moment investment and supply costs are still quite high

A Solar Pond for Feeding a Thermoelectric Generator or an Organic Rankine Cycle System

The world energy demand is continuously growing, which means an increase in consumption for all modern fuels or stronger effort on the development and improvement of renewable technologies. Moreover, Developing Countries claims more energy and they have often wide unutilized or unusable lands. The solar energy represents a useful opportunity for these Countries. The Solar Pond is both a solar collector and a thermal storage for long period and is suitable to use in wide sunny areas. Solar pond technology is able to supply heat for several applications requiring low-grade thermal energy or for electrical power production. In order to produce electrical energy from solar ponds it is necessary to use systems fed by low enthalpy sources, such Thermoelectric Generator (TEG) and Organic Rankine Cycle (ORC). In this paper, a model of a Solar Pond for power generation is analyzed in conjunction with an Organic Rankine Cycle. The model has been validated using climate data of an area near to Palermo city (Italy) and exactly the Test Reference Year developed by the Authors

Uno scrittore-viaggiatore: Nicolas Bouvier (1929-1998) e la sua prima biografia

Chi era Nicolas Bouvier? Un ginevrino fuori dal comune, uno scrittore dalla raffinatissima espressione, un infaticabile viaggiatore, un fotografo curioso, un documentarista serio ed affidabile. Era nato a Ginevra il 6 marzo 1929, in seno ad una famiglia borghese e fin dall’adolescenza aveva avuto un accesso privilegiato a tutte le espressioni visive, musicali e culturali della Ginevra colta del tempo. Le amicizie di famiglia lo avevano inoltre avvicinato alla cultura delle università tedesche..

Longitudinal Development of Refractive Error in Children With Accommodative Esotropia: Onset, Amblyopia, and Anisometropia.

Purpose: We investigated longitudinal changes of refractive error in children with accommodative esotropia (ET) throughout the first 12 years of life, its dependence on age at onset of ET, and whether amblyopia or anisometropia are associated with defective emmetropization. Methods: Longitudinal refractive errors in children with accommodative ET were analyzed retrospectively. Eligibility criteria included: initial hyperopia ≥+4.00 diopters (D), initial cycloplegic refraction before 4 years, at least 3 visits, and at least one visit between 7 and 12 years. Children were classified as having infantile (N = 30; onset ≤12 months) or late-onset (N = 78; onset at 18–48 months) accommodative ET. Cycloplegic refractions culled from medical records were converted into spherical equivalent (SEQ). Results: Although the initial visit right eye SEQ was similar for the infantile and late-onset groups (+5.86 ± 1.28 and +5.67 ± 1.26 D, respectively), there were different developmental changes in refractive error. Neither group had a significant decrease in hyperopia before age 7 years, but after 7 years, the infantile group experienced a myopic shift of −0.43 D/y. The late-onset group did not experience a myopic shift at 7 to 12 years. Among amblyopic children, a slower myopic shift was observed for the amblyopic eye. Among anisometropic children, the more hyperopic eye experienced more myopic shift than the less hyperopic eye. Conclusions: Children with infantile accommodative ET experienced prolonged hyperopia followed by a myopic shift after 7 years of age, consistent with dissociation between infantile emmetropization and school age myopic shift. In contrast, children with late-onset accommodative ET had little myopic shift before or after 7 years

La obra de Nelly Alarcón, un lenguaje textil con valor diferenciador

El presente artículo da cuenta de la investigación “Análisis del vestuario chileno entre los años 1968-1978. Identificación de los rasgos visuales, morfológicos y técnicos que caracterizaron al fenómeno de la Moda Latinoamericana”, que tiene por finalidad dilucidar los rasgos de diferenciación con respecto a la tendencia foránea. Son cinco los exponentes que conformaron la Moda Latinoamericana chilena del período en estudio, en donde cada uno de ellos propuso un relato territorial a sus diseños. Se presentará como caso de estudio la obra textil de Nelly Alarcón