Search results for "41"
showing 10 items of 3365 documents
Characterization and utilization of MFI zeolites and MCM-41 materials for gaseous pollutant adsorption
1999
Physisorption of n-hexane, trichloroethylene, tetrachloroethylene, carbon and nitrogen oxides on a microporous ZSM-5 (Si/Al=339) zeolite and an amorphous mesoporous MCM-41 (Si/Al=∞) sample was examined by isothermal thermogravimetry, manometry and calorimetry to evaluate the feasibility of using these porous materials for gaseous pollutant adsorption at room temperature. The adsorbents showed very interesting adsorption properties for hydrocarbons. ZSM-5 exhibited the strongest adsorption affinity and MCM-41 showed the largest adsorption capacity. Another main feature in this work was to observe a stepped-isotherm for the adsorption of C2Cl4 on ZSM-5. Such a substep located at very low rela…
Tunable Structure and Properties of Segmented Thermoplastic Polyurethanes as a Function of Flexible Segment
2019
Segmented thermoplastic polyurethanes (PUs) were synthetized using macrodiols with different functional groups (carbonate, ester, and /or ether) as a segment with a molar mass of 1000 and 2000 g/mol, and 4,4&rsquo
Impact of oral contraceptive use and menstrual phases on patellar tendon morphology, biochemical composition, and biomechanical properties in female …
2013
Sex differences exist with regards to ligament and tendon injuries. Lower collagen synthesis has been observed in exercising women vs. men, and in users of oral contraceptives (OC) vs. nonusers, but it is unknown if OC will influence tendon biomechanics of women undergoing regular training. Thirty female athletes (handball players, 18–30 yr) were recruited: 15 long-term users of OC (7.0 ± 0.6 yr) and 15 nonusers (>5 yr). Synchronized values of patellar tendon elongation (obtained by ultrasonography) and tendon force were sampled during ramped isometric knee extensor maximum voluntary contraction to estimate mechanical tendon properties. Furthermore, tendon cross-sectional area and lengt…
Neural Network Based Finite-Time Stabilization for Discrete-Time Markov Jump Nonlinear Systems with Time Delays
2013
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2013/359265 Open Access This paper deals with the finite-time stabilization problem for discrete-time Markov jump nonlinear systems with time delays and norm-bounded exogenous disturbance. The nonlinearities in different jump modes are parameterized by neural networks. Subsequently, a linear difference inclusion state space representation for a class of neural networks is established. Based on this, sufficient conditions are derived in terms of linear matrix inequalities to guarantee stochastic finite-time boundedness and stochastic finite-time stabi…
Distributed Consensus for Discrete-Time Directed Networks of Multiagents with Time-Delays and Random Communication Links
2013
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2013/158731 Open Access This paper is concerned with the leader-following consensus problem in mean-square for a class of discrete-time multiagent systems. The multiagent systems under consideration are the directed and contain arbitrary discrete time-delays. The communication links are assumed to be time-varying and stochastic. It is also assumed that some agents in the network are well informed and act as leaders, and the others are followers. By introducing novel Lyapunov functionals and employing some new analytical techniques, sufficient conditi…
Tobacco Use Documenting Policy and Its Association With Pupils’ Smoking and Their Perception of the Enforcement of School Smoking Bans in Finland
2014
Finnish national data sets on schools (N = 496) and pupils (N = 74,143; 14–16 years) were used to study whether a systematic documenting policy for the violations of school smoking bans was associated with pupils’ smoking and their perceptions on the enforcement of smoking bans. Attending a school with a systematic documenting policy was associated with perceptions that smoking is prohibited and restrictions monitored, with lower levels of smoking in the vicinity of the school during the school day, but not with smoking prevalence. Findings suggest that a consistent documenting policy could be an effective tool for reducing pupils’ smoking in schools.
Una tabla inédita de Fernando Yáñez y nueva luz sobre su estancia en Almedina (1518-1525)
2020
The contribution presents a new acquisition for the catalog of Fernando Yáñez, a Holy Family dating back to 1523, shedding new light on the artist?s production in the third decade of the sixteenth century during his return to Almedina, his birthplace, in a time frame that divides the works for Valencia, like the retablo mayor for the city?s cathedral, from his altarpieces for Cuenca.
Estudio transversal de medición de la composición corporal en pacientes con cáncer mediante antropometría y técnicas de imagen médica
2019
Introducción: Analizar la composición corporal tanto mediante técnicas antropométricas y parámetros bioquímicos clásicos, como mediante técnicas modernas utilizando tomografía computarizada (TC), en pacientes oncológicos antes de iniciar el tratamiento con radioterapia.Metodología: Se analizaron de forma retrospectiva 22 pacientes con diversos tumores del aparato digestivo, que fueron sometidos al TC de planificación antes de iniciar el tratamiento con radioterapia, y que disponían de un corte axial en la tercera vértebra lumbar. Para analizar la composición corporal, se determinaron tanto parámetros antropométricos y bioquímicos clásicos, como la determinación de la masa muscular mediante …
Tomografía computarizada a nivel de C3 y dinamometría como técnicas de diagnóstico de sarcopenia en pacientes con cáncer de cabeza y cuello
2020
Introducción: Estudio piloto que determina el diagnóstico de sarcopenia mediante tomografía computarizada (TC) a nivel de la tercera vértebra cervical (C3) y dinamometría en pacientes con cáncer de cabeza y cuello. Comparación de la masa magra (MM) determinada mediante TC con técnicas clásicas de antropometría y dinamometría.Material y métodos: Se analizó la MM y el tejido adiposo mediante TC a nivel de C3 en 37 pacientes oncológicos mediante Unidades Hounsfield (UH). Posteriormente, se calculó el índice musculoesquelético (IME) y se determinó la fuerza prensora de mano para la determinación de sarcopenia. Por último, se comparó el IME mediante técnicas de valoración antropométrica clásica …
Improved Switching Strategy for Selective Harmonic Elimination in DC-AC Signal Generation via Pulse-Width Modulation
2013
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2013/870904 Open Access We present an advanced design methodology for pulse-width-modulated (PWM) DC-AC signal generation. Using design methods based on the Walsh transform, AC sinusoidal signals can be approximated by suitable PWM signals. For different AC amplitudes, the switching instants of the PWM signals can be efficiently computed by using appropriate systems of explicit linear equations. However, the equation systems provided by conventional implementations of this approach are typically only valid for a restricted interval of AC amplitudes a…