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

hepatitis b virus long term impact of antiviral therapy nucleot s ide analogues nucs

The goal of antiviral therapy is to improve the quality of life and survival of patients with chronic hepatitis B (CHB) by halting the progression to cirrhosis, end-stage liver disease or hepatocellular carcinoma (HCC), thus preventing anticipated liver-related death. Oral administration of potent and less resistance-prone nucleot(s)ide analogues (NUCs), such as entecavir (ETV) and tenofovir disoproxil fumarate (TDF) has become the most popular treatment strategy worldwide because of their excellent efficacy and safety profile as well as easy management confirmed in both registration trials and in clinical practice studies. Long-term administration of ETV or TDF suppresses HBV replication in >95% of patients, resulting in biochemical remission, histological improvement including the regression of cirrhosis and prevention or reversal of clinical decompensation but not the development of HCC, particularly in patients with cirrhosis. Moreover, NUCs can be administered to all patients including those with severe liver disease, the elderly and in those who do not respond, are unwilling to take or have contraindications to interferon. The need for long-term, perhaps indefinite, treatment is the main limitation of NUCs therapy with the associated costs, unknown long-term safety and the low rates of hepatitis B surface antigen (HBsAg) seroclearance, which is still the best stopping rule for NUCs-treated patients with cirrhosis

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

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

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

Transient interfacial tension and dilatational rheology of diffuse polymer-polymer interfaces

We demonstrate the influence of molecular weight and molecular weightasymmetry across an interface on the transient behavior of the interfacial tension. The interfacial tension was measured as a function of time for a range of polymer combinations with a broadrange of interfacial properties using a pendant/ sessile drop apparatus. The results show that neglecting mutual solubility, assumed to be a reasonable approximation in many cases, very often does not sustain. Instead, a diffuse interface layer develops in time with a corresponding transient interfacial tension. Depending on the specific combination of polymers, the transient interfacial tension is found to increase or decrease with time. The results are interpreted in terms of a recently proposed model\cite{Shi_etal2004}, giving relativecharacteristic diffusion time scales in terms of molecular weight, molecular weight distribution and viscosities. However, the time scales obtained from this theoretical approach do not give a conclusive trend. Using oscillatory dilatational interfacial experiments the viscoelastic behavior of these diffusive interfaces is demonstrated. The time evolution of the interfacial tension and thedilatational elasticity show the same trend aspredicted by the theory of diffuse interfaces, supporting the idea that the polymer combinations under consideration indeed form diffuse interfaces. The dilatational elasticity and the dilatationalviscosity show a frequency dependency that is described qualitatively by a simple Fickian diffusion model and quantitatively by a Maxwell model. The characteristic diffusion times provided by the lattershow that the systems with thick interfaces (tens of micrometers and more) can be considered as slowdiffusive systems while the systems with thinner interfaces (a few micrometers and less) can be considered as fast diffusive systems