RF and IF mixer optimum matching impedances extracted by large-signal vectorial measurements

This paper introduces a new technique that allows us to measure the admittance conversion matrix of a two-port device,using a Nonlinear Vector Network Analyzer.This method is applied to extract the conversion matrix of a 0.2 µµµµm pHEMT,driven by a 4.8 GHz pump signal,at different power levels,using an intermediate frequency of 600 MHz.The issue on data inconsistency due to phase randomization among different measurements is discussed and a proper pre- processing algorithm is proposed to fix the problem. The output of this work consists of a comprehensive experimental evaluation of up-and down-conversion maximum gain,stability,and optimal RF and IF impedances

In situ atomic force microscopy in the study of electrogeneration of polybithiophene on Pt electrode

Electrochemical AFM technique has been used for the in situ study of the electrogeneration-deposition process of polybithiophene at varying the polymerisation conditions, such as supporting electrolyte, i.e., LiClO4 or tetrabutylammonium hexafluorophosphate, and polymerisation procedure, i.e., either potentiostatic or potentiodynamic method. In order to better follow the evolution of the morphology of the deposit, particularly during the early stages of the polymer film growth, a suitable home-made electrochemical cell has been used

Short Time Dynamic Interfacial Tension as Measured with Capillary Pressure Technique

Dynamic interfacial tension measurements in the short time range are a major request for controlling interfacial processes in modern, highly dynamic technologies. Capillary pressure measurements for growing and oscillating drops represent a good way to fulfil these requirements. The corresponding quantitative data analysis, however, requires the solution of rather complex theories on the hydrodynamics of growing drops and the adsorption dynamics at the drop surface and possible mass transfer across interfaces for liquid/liquid systems

Highly efficient photoanodes based on cascade structural semiconductors of Cu2Se/CdSe/TiO2: a multifaceted approach to achieving microstructural and compositional control

Hydrogen produced by splitting water is receiving significant attention due to the rising global energy demand and growing climate concerns. The photocatalytic decomposition of water converts solar energy into clean hydrogen, and may help mitigate the crisis of fossil fuel depletion. However, the photocatalytic hydrogen production remains challenging to obtain high and stable photoconversion efficiency. Here, we report a highly efficient photoanode based on the coaxial heterogeneous cascade structure of Cu2Se/CdSe/TiO2 synthesized via a simple room-temperature and low-cost electrochemical deposition method. The microstructure and composition of the Cu2Se top layer are regulated and controlled by doping Cu with various amounts in different zones of the CdSe/TiO2 coaxial heterojunction and then using a simple integral annealing process. Surprisingly, a little effort made to achieve the Cu2Se top layer utilizing such doped CdSe/TiO2 exhibits a significant enhancement in photocatalytic activity. The maximum stable photocurrent density of the sample with the optimal copper zone and doping concentration has reached up to 28 mA cm−2, which can be attributed to the success in the uniform dispersion of the three-layer heterogeneous nanojunctions among the anatase nanotube wall from the top to the bottom. This results in a stepwise structure of band-edge levels in the Cu2Se/CdSe/TiO2 photoelectrode that is conducive to enhancing effectively the separation of the photogenerated electron–hole pairs

Análisis y mejora de la línea de producción de silicatos de malpica mediante flexsim

La industria se encuentra en un ambiente cada vez más competitivo en el que las empresas buscan nuevas formas de mejorar y conseguir una ventaja competitiva en el mercado. En el ámbito industrial, las herramientas informáticas como los softwares de simulación permiten a las empresas estudiar y analizar sus procesos actuales, así como alternativas de mejora a través de la simulación virtual de procesos. En el presente trabajo se realiza el estudio de la línea de Silicatos de Malpica, identificando los cuellos de botella existentes, y proponiendo algunas alternativas de mejora a través de la representación virtual de la planta industrial con el software Flexsim. Por otra parte, con este estudio, se pone a disposición de futuros alumnos de Ingeniería en Organización Industrial un ejemplo de simulación virtual de procesos, para facilitar el aprendizaje y manejo del software.Industria gero eta ingurumen lehiakorrago batean aurkitzen da, hori dela eta enpresek hobetzeko modu berriak eta merkatuan abantaila lehiakor bat lortzea bilatzen dute. Industri arloan, simulazio-softwareko tresna informatikoek egungo prozesuak ikasteko eta aztertzeko aukera ematen die enpresei, eta simulaketa prozesu birtualaren bidez hobekuntza alternatiboak ere. Lan honetan Malpica Silikatoen linearen azterketa egiten da, izatedun botilen lepoa identifikatzen, eta hainbat hobekuntza alt ernatibo proposatzen Flexsim softwarearekin industria-lantegiaren ordezkaritza birtualaren bidez. Bestalde, ikerlan honekin, Industria Antolakuntzako Ingeniaritzako graduko etorkizuneko ikasleei eskuragarri ipintzen da prozesu simulazio birtualen adibide bat, softwarearen ikaskuntza eta kudeaketa errazteko.The industry is in an increasingly competitive environment in which companies seek new ways to improve and achieve a competitive advantage in the market In the industrial field, computer tools such as simulation software allow companies to study and anylize their current processes, as well as alternatives for improvement through virtual process simulation. In the present project the Silicatos de Malpica ́s line researchis carried out, identifying existing bottlenecks, and proposing some alternatives for improvement through the virtual representation of the industrial plant with the Flexsim software. On the other hand, this research makes available to future students of Engineering in Industrial Organization access to an example of virtual simulation of processes, to facilitate the learning and management of the software

Análisis y mejora de la línea de producción de silicatos de malpica mediante flexsim

La industria se encuentra en un ambiente cada vez más competitivo en el que las empresas buscan nuevas formas de mejorar y conseguir una ventaja competitiva en el mercado. En el ámbito industrial, las herramientas informáticas como los softwares de simulación permiten a las empresas estudiar y analizar sus procesos actuales, así como alternativas de mejora a través de la simulación virtual de procesos. En el presente trabajo se realiza el estudio de la línea de Silicatos de Malpica, identificando los cuellos de botella existentes, y proponiendo algunas alternativas de mejora a través de la representación virtual de la planta industrial con el software Flexsim. Por otra parte, con este estudio, se pone a disposición de futuros alumnos de Ingeniería en Organización Industrial un ejemplo de simulación virtual de procesos, para facilitar el aprendizaje y manejo del software.Industria gero eta ingurumen lehiakorrago batean aurkitzen da, hori dela eta enpresek hobetzeko modu berriak eta merkatuan abantaila lehiakor bat lortzea bilatzen dute. Industri arloan, simulazio-softwareko tresna informatikoek egungo prozesuak ikasteko eta aztertzeko aukera ematen die enpresei, eta simulaketa prozesu birtualaren bidez hobekuntza alternatiboak ere. Lan honetan Malpica Silikatoen linearen azterketa egiten da, izatedun botilen lepoa identifikatzen, eta hainbat hobekuntza alt ernatibo proposatzen Flexsim softwarearekin industria-lantegiaren ordezkaritza birtualaren bidez. Bestalde, ikerlan honekin, Industria Antolakuntzako Ingeniaritzako graduko etorkizuneko ikasleei eskuragarri ipintzen da prozesu simulazio birtualen adibide bat, softwarearen ikaskuntza eta kudeaketa errazteko.The industry is in an increasingly competitive environment in which companies seek new ways to improve and achieve a competitive advantage in the market In the industrial field, computer tools such as simulation software allow companies to study and anylize their current processes, as well as alternatives for improvement through virtual process simulation. In the present project the Silicatos de Malpica ́s line researchis carried out, identifying existing bottlenecks, and proposing some alternatives for improvement through the virtual representation of the industrial plant with the Flexsim software. On the other hand, this research makes available to future students of Engineering in Industrial Organization access to an example of virtual simulation of processes, to facilitate the learning and management of the software