Search results for "ITC"

Stochastic model of memristor based on the length of conductive region

2021

Abstract We propose a stochastic model of a voltage controlled bipolar memristive system, which includes the properties of widely used dynamic SPICE models and takes into account the fluctuations inherent in memristors. The proposed model is described by rather simple equations of Brownian diffusion, does not require significant computational resources for numerical modeling, and allows obtaining the exact analytical solutions in some cases. The noise-induced transient bimodality phenomenon, arising under resistive switching, was revealed and investigated theoretically and experimentally in a memristive system, by finding a quite good qualitatively agreement between theory and experiment. B…

Assessment of MOSFET switching losses in an LLC converter by a calorimetric method

2023

The present work aims to implement a calorimetric method to measure the power dissipated during MOSFET switching in a high efficiency LLC resonant converter. The power dissipated from switching can significantly impact the total power dissipated by the device and consequent efficiency, so correct quantification is fundamental for optimizing the devices and increasing the efficiency of the converters. In LLC converters, this type of dissipated power cannot be measured with standard methods such as measurement with oscilloscopes as some of the energy that is recovered and not dissipated. The calorimetric method requires reasonably accurate measurement of thermal resistance and the temperature…

A fuel cell-supercapacitor power supply for portable applications

2008

Due to the increasing number and complexity of the available functions, modern handheld devices require higher and higher current slew rates. Customers' requirements lead to a growing interest in longer-lasting power, fast transient response power supply systems and minimization of system weight, volume and cost. Fuel cell based hybrid systems are designed to meet all requirements. In this paper, a fuel cell-supercapacitor hybrid power supply for portable applications is proposed. The power management subsystem is designed and simulation results are shown to test the efficiency of the control algorithm. ©2008 IEEE.

Characterization of the Microshell Surface Using Holography

2011

AbstractTo characterize the shape, the quality, and the roughness of microshells, digital holographic microscopy technology is used because it offers an appropriate ability to these studies. It captures holograms to reconstruct a double image, one for the intensity and another one for the phase. Using rotation axis, bump counting for the complete microshell surface is possible with a very high speed. Using image stitching and three-dimensional surface rebuilding software, mapping can be done in a few minutes. Each bump can then be characterized on the map by its position, diameter, and height.

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

2019

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained ra…

EMI Filter Re-Design in a SMPS with Inductor in Saturation

2021

This paper analyzes the design issues of the input EMI (Electro-Magnetic Interference) filter's in a switching mode power supply where the power inductor is operated in saturation. Starting with a SMPS equipped with linear inductor, the input filter is firstly designed to comply with Standards. Then, a new inductor with a smaller core size is employed in the same SMPS to exploit saturation. The EMI filter is re-designed, taking into account the increase of EMI introduced by the non-linear operation of the inductor. Finally, the reduction of the inductor's size and cost is compared with the increased size and cost of the EMI filter.

Modeling and simulation of a digital control design approach for power supply systems

2006

Electronic designers need to model and simulate system features as close as possible to its effective behaviour. Moreover, today, electronics systems are often composed of mixed analog and digital components. The increasing complexity has led to the use of different simulation softwares, each one specific for a particular level of abstraction: mathematical, circuital, behavioural, etc. In order to simulate the entire system these softwares should work together: co-simulation is necessary for digitally controlled power electronics systems. In this paper, the modeling of a digitally controlled switching power supply system using MATLAB/Simulink, ALDEC Active-HDL and Powersys PSIM is presented…

Cooperative Thermal and Optical Switching of Spin States in a New Two-Dimensional Coordination Polymer

2003

{Fe(pmd)2[Cu(CN)2]2} (pmd = pyrimidine) displays a rigid two-dimensional structure and undergoes thermal- and optical-driven spin crossover behaviour; cooperative elastic coupling between iron(II) ions in the framework induces thermal hysteresis in the HS↔LS conversion and sigmoidal HS→LS relaxation of the photo-induced HS state at low temperatures. Niel, Virginie, Virginie.Niel@uv.es ; Galet Domingo, Ana Guadalupe, Ana.Galet@uv.es ; Gaspar Pedros, Ana Belen, Ana.B.Gaspar@uv.es ; Real Cabezos, Jose Antonio, Jose.A.Real@uv.es

Fast electroclinic switching in a ferroelectric LC-polysiloxane

1992

NFATc1 affects mouse splenic B cell function by controlling the calcineurin–NFAT signaling network

2011

Mouse B cells lacking NFATc1 exhibit defective proliferation, survival, isotype class switching, cytokine production, and T cell help.