RF MEMS impedance tuners for 6–24 GHz applications

RF MEMS tuners with wide impedance coverage have been developed for 6–24 GHz noise parameter and load-pull measurement systems. The tuners are based on triple-, double-, and single-stub topologies loaded with switched MEMS capacitors. Several designs are presented, and they use 10–13 switched MEMS capacitors to produce 1024–8192 (2 10 –2 13 ) different impedances. The measured impedance coverage agrees well with simulations and it is the widest ever measured impedance coverage from any planar tuner to-date. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56026/1/20220_ftp.pd

Very Wideband automated On-Wafer noise figure and Gain measurements At 50-110

On-wafer noise figure and insertion gain measurement set-ups have been developed over 50-110 GHz frequency range. Wafer scale noise figure and insertion gain measurements can be done in an automatic manner using PC controlled automated probe station and in-house written software. In narrow band measurements, large systematic errors may remain undiscovered. These errors are usually caused by reflections in the set-up, which are difficult to calibrate out. Wideband measurements are often the only method, which can efficiently reveal these errors. This aspect is increasingly important as frequency increases

Comparison of the Growth and Thermal Properties of Nonwoven Polymers after Atomic Layer Deposition and Vapor Phase Infiltration

The growth mechanism of Atomic Layer Deposition (ALD) on polymeric surfaces differs from growth on inorganic solid substrates, such as silicon wafer or glass. In this paper, we report the growth experiments of Al2O3 and ZnO on nonwoven poly-L-lactic acid (PLLA), polyethersulphone (PES) and cellulose acetate (CA) fibres. Material growth in both ALD and infiltration mode was studied. The structures were examined with a scanning electron microscope (SEM), scanning transmission electron microscope (STEM), attenuated total reflectance-fourier-transform infrared spectroscopy (ATR-FTIR) and 27Al nuclear magnetic resonance (NMR). Furthermore, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis were used to explore the effect of ALD deposition on the thermal properties of the CA polymer. According to the SEM, STEM and ATR-FTIR analysis, the growth of Al2O3 was more uniform than ZnO on each of the polymers studied. In addition, according to ATR-FTIR spectroscopy, the infiltration resulted in interactions between the polymers and the ALD precursors. Thermal analysis (TGA/DSC) revealed a slower depolymerization process and better thermal resistance upon heating both in ALD-coated and infiltrated fibres, more pronounced on the latter type of structures, as seen from smaller endothermic peaks on TA

Comprobación de la presencia de probióticos en productos de uso oral

El objetivo principal de esta investigación fue comprobar la presencia de probióticos en productos de uso oral, comercializados en las diferentes farmacias ubicadas en la Colonia Médica de San Salvador, en las presentaciones de cápsulas, comprimidos masticables y sobres. Para la recolección de la muestra se utilizó una hoja de cotejo, que se aplicó para la identificación de los probióticos comercializados en cada una de las 16 farmacias en estudio, obteniendo un total de 24 muestras. Se realizó una descripción de cada uno de los productos con la normativa de etiquetado Reglamento Técnico Centroamericano RTCA 11.01.02:04 Productos Farmacéuticos. Etiquetado de Productos Farmacéuticos para uso Humano. Así mismo un recuento en placa de bacterias ácido lácticas, también una identificación de los microrganismos tanto a nivel macroscópico como microscópico de las presentaciones de cápsulas, comprimidos masticables y sobres, se comparó con el estándar de referencia Lactobacillus rhamnosus. Obteniéndose los siguientes resultados: para las muestras de cápsulas su crecimiento en placa fue de 1.5x103 UFC/mL, las de comprimidos masticables su crecimiento fue de 1.3x103 UFC/mL y las de sobres de 1.9x103 UFC/mL. En las tres presentaciones el crecimiento en placa fue inferior al rango que establece la Organización de las Naciones Unidas para la Agricultura y la Organización Mundial de la Salud (FAO/OMS) de 106 a 109 UFC. Para ser considerado como probiótico y ejercer un efecto positivo para el consumidor. Se recomiendan nuevas investigaciones con diferentes marcas y presentaciones de probióticos, para poder confirmar si contiene la cantidad que especifica en los productos. La investigación de llevó a cabo en el Laboratorio de Microbiología del Centro de Investigaciones y Desarrollo en Salud (CENSALUD) de la Universidad de El Salvador, durante el periodo de 2017 al 2019

Comparison of the Growth and Thermal Properties of Nonwoven Polymers after Atomic Layer Deposition and Vapor Phase Infiltration

The growth mechanism of Atomic Layer Deposition (ALD) on polymeric surfaces differs from growth on inorganic solid substrates, such as silicon wafer or glass. In this paper, we report the growth experiments of Al2O3 and ZnO on nonwoven poly-L-lactic acid (PLLA), polyethersulphone (PES) and cellulose acetate (CA) fibres. Material growth in both ALD and infiltration mode was studied. The structures were examined with a scanning electron microscope (SEM), scanning transmission electron microscope (STEM), attenuated total reflectance-fourier-transform infrared spectroscopy (ATR-FTIR) and 27Al nuclear magnetic resonance (NMR). Furthermore, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis were used to explore the effect of ALD deposition on the thermal properties of the CA polymer. According to the SEM, STEM and ATR-FTIR analysis, the growth of Al2O3 was more uniform than ZnO on each of the polymers studied. In addition, according to ATR-FTIR spectroscopy, the infiltration resulted in interactions between the polymers and the ALD precursors. Thermal analysis (TGA/DSC) revealed a slower depolymerization process and better thermal resistance upon heating both in ALD-coated and infiltrated fibres, more pronounced on the latter type of structures, as seen from smaller endothermic peaks on TA

Cardiac monitoring of dogs via smartphone mechanocardiography : a feasibility study

Abstract Background In the context of monitoring dogs, usually, accelerometers have been used to measure the dog’s movement activity. Here, we study another application of the accelerometers (and gyroscopes)—seismocardiography (SCG) and gyrocardiography (GCG)—to monitor the dog’s heart. Together, 3-axis SCG and 3-axis GCG constitute of 6-axis mechanocardiography (MCG), which is inbuilt to most modern smartphones. Thus, the objective of this study is to assess the feasibility of using a smartphone-only solution to studying dog’s heart. Methods A clinical trial (CT) was conducted at the University Small Animal Hospital, University of Helsinki, Finland. 14 dogs (3 breeds) including 18 measurements (about one half of all) where the dog’s status was such that it was still and not panting were further selected for the heart rate (HR) analysis (each signal with a duration of 1 min). The measurement device in the CT was a custom Holter monitor including synchronized 6-axis MCG and ECG. In addition, 16 dogs (9 breeds, one mixed-breed) were measured at home settings by the dog owners themselves using Sony Xperia Android smartphone sensor to further validate the applicability of the method. Results The developed algorithm was able to select 10 good-quality signals from the 18 CT measurements, and for 7 of these, the automated algorithm was able to detect HR with deviation below or equal to 5 bpm (compared to ECG). Further visual analysis verified that, for approximately half of the dogs, the signal quality at home environment was sufficient for HR extraction at least in some signal locations, while the motion artifacts due to dog’s movements are the main challenges of the method. Conclusion With improved data analysis techniques for managing noisy measurements, the proposed approach could be useful in home use. The advantage of the method is that it can operate as a stand-alone application without requiring any extra equipment (such as smart collar or ECG patch)

Objectively measured physical activity profile and cognition in Finnish elderly twins

Introduction We studied whether objectively measured physical activity (PA) and sedentary behavior (SB) are associated with cognition in Finnish elderly twins. Methods This cross-sectional study comprised twins born in Finland from 1940 to 1944 in the Older Finnish Twin Cohort (mean age, 72.9 years; 726 persons). From 2014 to 2016, cognition was assessed with a validated telephonic interview, whereas PA was measured with a waist-worn accelerometer. Results In between-family models, SB and light physical activity had significant linear associations with cognition after adjusting for age, sex, wearing time, education level, body mass index, and living condition (SB: β-estimate, −0.21 [95% confidence intervals, −0.42 to −0.003]; light physical activity: β-estimate, 0.30 [95% confidence intervals, 0.02–0.58]). In within-family models, there were no significant linear associations between objectively measured PA and cognition. Discussion Objectively measured light physical activity and SB are associated with cognition in Finnish twins in their seventies, but the associations were attributable to genetic and environmental selection.Peer reviewe

Chronic diseases and objectively monitored physical activity profile among aged individuals - a cross-sectional twin cohort study

Introduction: High physical activity (PA) at old age indicates good functional capacity enabling independent living. We investigated how different disease conditions are associated with measured PA indicators in old women and men, and whether they recognize this association. Materials and methods: This cross-sectional twin cohort study in Finland comprised 779 individuals (276 complete twin pairs, including 117 monozygotic pairs), who participated in hip-worn accelerometer monitoring of PA and responded to questions on diseases and mobility limitations at mean age of 73 (range 71-75). Results: Of the participants, 23.2% reported having a disease restricting mobility. With sex and age in the regression model, the reported disease restricting mobility explained 11.8% of the variation in moderate-to-vigorous PA (MVPA) and 10.4% of the variation in daily steps. Adding stepwise other self-reported diseases and body mass index to the model increased the explanatory power for MVPA up to 18.5% and 25.5%, and for daily steps up to 16.0% and 20.7%, respectively. In the co-twin control analysis the PA differences were smaller in disease-discordant monozygotic than dizygotic pairs. Conclusions: Chronic disease conditions are associated with low PA, which individuals may not always recognize. Shared genetic factors may explain part of the associations.Key messages Among community-dwelling older men and women one-fourth of the variation in objectively measured moderate-to-vigorous physical activity is accounted for by age, sex, body mass index and self-reported diseases. Occurrence of chronic diseases is associated with low physical activity and individuals do not always recognize this. Healthcare professionals should pay attention to the low physical activity and mobility of individuals with chronic disease conditions before these result in limitations in independent living.Peer reviewe