Estimation of RF PA Non-Linearities After Cross-Correlating Current and Output Voltage

The estimation of 1 dB compression and third-order intercept points can be obtained after the cross-correlation between dynamic current and output voltage of radio frequency power amplifiers. This estimation is performed using actual power measures and not power inferred from voltage measurements. The underlining theory and a correlator that allows implementing this measurement on-chip are presented. The trade-off between measuring voltage and the actual power is also discussed and it is shown that different information concerning the output load is obtained when observing the PA's output voltage and power. Simulation results, obtained with the model of a prototype demonstration chip, show that good accuracy can be obtained with relatively simple measurement conditions. These results include the analysis of optimum stimuli amplitudes and the effect of noise in estimation accuracy

Novel laser-induced luminescence resulting from benzophenone/O-propylated p-tert-butylcalix[4]arene complexes. A diffuse reflectance study

Laser-induced room temperature luminescence of air-equilibrated benzophenone/O-propylated p-tert-butylcalix[ 4] arene solid powdered samples revealed the existence of a novel emission, in contrast with benzophenone/p-tertbutylcalix[ 4] arene complexes, where only benzophenone emits. This novel emission was identified as phosphorescence of 1-phenyl-1,2-propanedione, which is formed as the result of an hydrogen atom abstraction reaction of the triplet excited benzophenone from the propoxy substituents of the calixarene. Room temperature phosphorescence was obtained in air-equilibrated samples in all propylated hosts. The decay times of the benzophenone emission vary greatly with the degree of propylation, the shortest lifetimes being obtained in the tri- and tetrapropylated calixarenes. Triplet - triplet absorption of benzophenone was detected in all cases, and is the predominant absorption in the p-tert-butylcalix[ 4] arene case, where an endo-calix complex is formed. Benzophenone ketyl radical formation occurs with the O-propylated p-tert-butylcalix[ 4] arenes hosts, suggesting a different type of host/guest molecular arrangement. Diffuse reflectance laser. ash photolysis and gas chromatography - mass spectrometry techniques provided complementary information, the former about transient species and the latter regarding the final products formed after light absorption. Product analysis and identification clearly show that the two main degradation photoproducts following laser excitation in the propylated substrates are 1-phenyl-1,2- propanedione and 2- hydroxybenzophenone, although several other minor photodegradation products were identified. A detailed mechanistic analysis is proposed. While the solution photochemistry of benzophenone is dominated by the hydrogen abstraction reaction from suitable hydrogen donors, in these solid powdered samples, the alpha-cleavage reaction also plays an important role. This finding occurs even with one single laser pulse which lasts only a few nanoseconds, and is apparently related to the fact that scattered radiation exists, due to multiple internal reflections possibly trapping light within non-absorbing microcrystals in the sample, and is detected until at least 20 mus after the laser pulse. This could explain how photoproducts thus formed could also be excited with only one laser pulse

Educational needs in people with ankylosing spondylitis and psoriatic arthritis: A cross-sectional study

Objective: To assess the educational needs of people with Ankylosing Spondylitis (AS) and Psoriatic Arthritis (PsA), test differences across patient subgroups and identify factors independently associated with their educational needs.Methods: This was a cross-sectional analytic study. Patients with AS and PsA completed the Portuguese version of the Educational Needs Assessment Tool (PortENAT). Data were Rasch-transformed before descriptive and inferential analyses were undertaken. Univariable and multivariable analyses were used to determine differences between patient subgroups and factors independently associated with their educational needs.Results: The study included 121 patients with AS and 132 with PsA. The level of educational needs varied by diagnostic group, but higher needs for both subgroups were reported regarding the “Disease process”, “Feelings” and “Managing pain” domains. Overall, patients with AS had a higher level of educational needs than those with PsA. In both disease groups, female gender was independently associated with higher educational needs. In the PsA group, a shorter disease duration was independently associated with higher educational needs in the following domains: “Managing pain”, “Movement” and “Feelings”.Conclusion: Educational needs vary by diagnostic group, gender and disease duration. These differences merit consideration in the design of patient education interventions

Auto-calibrated capacitive MEMS accelerometer

An electronic calibration technique forcapacitive MEMS accelerometers based on themeasurement of pull-in voltages is described. Acombination of pull-in voltages and resonance frequencymeasurements can be used for the estimation of processinducedvariations in device dimensions from layout anddeviations in material properties from nominal value,which enables auto-calibration. Measurements onfabricated devices confirm the validity of the proposedtechnique and electronic calibration is experimentallydemonstrated

Capacitive MEMS accelerometers testing mechanism for auto-calibration and long-term diagnostics

A test technique for capacitive MEMSaccelerometers and electrostatic micro-actuators based onthe measurement of pull-in voltages is described. Acombination of pull-in voltages and resonance frequencymeasurements can be used for the estimation of processinducedvariations in device dimensions from layout anddeviations in material properties from nominal value,which enables auto-calibration. Preliminary measurementson fabricated devices confirm the validity of the proposedtechnique. Moreover, long-term pull-in measurements haveindicated the suitability of the approach as in-systemdiagnostic tool

Muscular Strength Imbalances Are not Associated with Skin Temperature Asymmetries in Soccer Players

Although strength imbalances using isokinetic dynamometer have been examined for injury risk screening in soccer players, it is very expensive and time-consuming, making the evaluation of new methods appealing. The aim of the study was to analyze the agreement between muscular strength imbalances and skin temperature bilateral asymmetries as well as skin temperature diferences in the hamstrings and quadriceps. The skin temperature of the anterior and posterior thigh of 59 healthy male soccer athletes was assessed at baseline using infrared thermography for the identification of hamstrings-quadriceps skin temperature diferences and thermal asymmetries (>0.5 ºC). Subsequently, concentric and eccentric peak torque of the quadriceps and hamstrings were considered in the determination of the ratios, as well as muscular asymmetries (>15%). When considering the torque parameters, 37.3% (n = 22) of the players would be classified as high risk for injuries. The percentage of those presenting skin temperature imbalances superior to 0.5 C was 52.5% (n = 31). The skin temperature assessment showed sensitivity (22%) and specificity (32.2%) to identify torque asymmetries, demonstrating the inability to identify false negatives (15.3%) and false positives (30.5%) from all soccer athletes. In conclusion, skin temperature diferences between hamstrings and quadriceps could be more related to thermoregulatory factors than strength imbalances

AS CONTRIBUIÇÕES DA QUARTA REVOLUÇÃO INDUSTRIAL PARA ECOINOVAÇÕES: UMA REVISÃO BIBLIOMÉTRICA

A partir desenvolvimento dos setores da tecnológicos, avista-se inovações que têm se mostrado satisfatórias, sobretudo diante dos efeitos da urbanização. No entanto, cada vez mais se vê a necessidade da modernização tecnológica focada em sustentabilidade, de modo a alcançar equilíbrio entre o ambiental, o social e o econômico. Diante disso, levanta-se a questão de se saber qual o verdadeiro impacto das preocupações ambientais na inovação desenvolvida e adotada pelos diversos agentes econômicos. O objetivo deste artigo, portanto, é identificar como as tecnologias trazidas pela Quarta Revolução Industrial podem contribuir para a adoção de estratégias de ecoinovação.[1] Center for Sustainable Development, University of Southern Santa Catarina (UNISUL), e-mail:

Catalyzed and non-catalyzed synthesis of bioactive monastrol

The bioactive 3,4-dihydropyrimidin-2(1H)-thione derivative known as Monastrol was synthesized under catalyzed and non-catalyzed conditions through the Biginelli multicomponent reaction under solvent-free conditions. The use of two Lewis acids (FeCl3 and CuCl2) and two Brønsted acids (HCl and CF3COOH) as catalysts improved the reaction yields of the transformation compared with the non-catalyzed reaction. The experiments investigated catalysis and its role, the importance of multicomponent reactions and their green features, and the application of these concepts to the synthesis of a biologically important structure

The impact of patient global assessment in the definition of remission as a predictor of long-term radiographic damage in patients with rheumatoid arthritis: protocol for an individual patient data meta-analysis

BACKGROUND: Remission is the target for management of rheumatoid arthritis (RA) and intensification of immunosuppressive therapy is recommended for those that do not achieve this status. Patient global assessment (PGA) is the single patient reported outcome considered in the American College of Rheumatology/European League Against Rheumatism remission criteria, but its use as target has been questioned. The primary aim of this study is to assess whether excluding PGA from the definition of disease remission changes the association of disease remission with long-term radiographic damage and physical function in patients with RA. METHODS: Individual Patient Data Meta-analysis using data from randomized controlled trials of biological and targeted synthetic agents, identified through ClinicalTrials.gov and PubMed. Different remission states will be defined: (i) 4v-remission [tender (TJC28) and swollen 28-joint counts (SJC28) both≤1, C-reactive protein (CRP)≤1 (mg/dl), and PGA≤1 (0-10 scale)], (ii) 4v-near-remission (TJC28≤1, SJC28≤1, CRP≤1, and PGA>1), (iii) non-remission (TJC28>1 or SJC28>1 or CRP>1), all mutually exclusive, and (iv) 3v-remission (TJC28≤1, SJC28≤1, CRP≤1). Likelihood ratios will be used to descriptively compare whether meeting the 3v and 4v-remission criteria in a single visit (at 6 or 12 months) predicts good outcome in the second year (1-2y). Differences in the predictive value of PGA in the definition of remission will be assessed by comparing the three mutually exclusive disease states using logistic regression analysis. Good outcome is defined primarily by radiographic damage (no deterioration in radiographic scores, whatever the instrument used in each trial), and secondarily by functional disability (Health Assessment Questionnaire consistently ≤0.5 and no deterioration), and their combination ("overall good outcome"). Additional analyses will consider longer periods over which to (concurrently) define remission status and outcome (between 1-5y and 1-10y), different cut-offs to define good radiographic outcome (change ≤0.5, ≤3 and ≤5 in radiographic score), sustained remission and the influence of treatment and other clinical factors. DISCUSSION: If 4v-remission and 4v-near-remission are associated with a similar probability of good outcomes, particularly regarding structural damage, the 3v-remission (excluding PGA) could be adopted as the target for immunosuppressive therapy. Patients' perspectives would remain essential, but assessed separately from disease activity, using instruments adequate to guide adjunctive therapies. Systematic review registration: PROSPERO, CRD42017057099