Search results for "conduct"
showing 10 items of 4412 documents
Short-term effects of potassium fertilization on the hydraulic conductance of Laurus nobilis L.
2011
This study reports experimental evidence on the effect of short term potassium fertilization on potassium uptake, tissue concentration and hydraulic conductance of pot-grown laurel plants. Potassium uptake and loading into the xylem of laurel seedlings increased within 24 h from fertilization. Potassium was not accumulated in roots and leaves, but the [K+] of xylem sap was 80% higher in fertilized plants (+K) than in potassium starved plants (-K), likely as a result of recirculation between xylem and phloem. This increase in xylem sap [K+] resulted in a 45% increase in transpiration rate, a 30% increase in plant hydraulic conductance (Kplant) and a 120% increase in leaf specific conductivit…
Large‐scale lateral saturated soil hydraulic conductivity as a metric for the connectivity of subsurface flow paths at hillslope scale
2022
Lateral saturated soil hydraulic conductivity, K-s,K-l, is the soil property governing subsurface water transfer in hillslopes, and the key parameter in many numerical models simulating hydrological processes at the hillslope and catchment scales. Likewise, the hydrological connectivity of the lateral flow paths plays a significant role in determining the rate of the subsurface flow at various spatial scales. This study investigates the relationship between K-s,K-l and hydrological connectivity at the hillslope spatial scale. K-s,K-l was determined by the subsurface flow rates intercepted by drains and water table depths observed in a well network. The hydrological connectivity was evaluate…
Structural and Electrochemical Analysis of CIGS: Cr Crystalline Nanopowders and Thin Films Deposited onto ITO Substrates
2021
A new approach for the synthesis of nanopowders and thin films of CuInGaSe2 (CIGS) chalcopyrite material doped with different amounts of Cr is presented. The chalcopyrite material CuInxGa1 − xSe2 was doped using Cr to form a new doped chalcopyrite with the structure CuInxCryGa1 − x − ySe2, where x = 0.4 and y = 0.0, 0.1, 0.2, or 0.3. The electrical properties of CuInx CryGa1 − x − ySe2 are highly dependent on the Cr content and results show these materials as promising dopants for the fabrication thin film solar cells. The CIGS nano-precursor powder was initially synthesized via an autoclave method, and then converted into thin films over transparent substrates. Both crystalline precursor p…
Fatigue while driving in a car simulator : effects on vigilance performance and autonomic skin conductance
2010
In this vigilance research the effect of fatigue on driver’s voluntary reaction times (RT) and autonomic skin conductance (SC) was studied. Participants (n=17) drove approximately 3 hours in a simulator responding simultaneously on a peripheral visual vigilance task (PVVT). RTs were classified into 5 quintiles according to their latency. Also misses and misclassifications were explored. Results indicated that RTs increased linearly over time. SC amplitudes differed significantly between RT quintiles. Vigilance performance was the best when arousals were frequent but their magnitude remained relatively low. Frequent and high amplitude arousals in turn were associated with the worst performan…
In Situ Synthesis of Polythiophene and Silver Nanoparticles within a PMMA Matrix: A Nanocomposite Approach to Thermoelectrics
2022
The processability of organic thermoelectric materials plays a crucial role due to their clear advantages of applicability in large-scale areas compared to traditional inorganic counterparts. A promising way to process thermoelectric materials based on conductive polymers is through in situ polymerization in an insulating polymer matrix. This work shows an interpenetrating polymeric network based on polythiophene, silver nanoparticles (Ag NPs), and poly(methyl methacrylate) (PMMA) produced by the oxidative polymerization of terthiophene by an oxidizing silver salt in a PMMA matrix. Ag NPs are in situ synthesized simultaneously as a byproduct. The reaction occurs very fast in the solid state…
Personas mayores en riesgo: uso del preservativo ante las infidelidades
2019
Si bien las infecciones de transmisión sexual suelen relacionarse con etapas evolutivas tempranas, estudios recientes ponen el foco de atención en la población más mayor. Sin embargo, pocos esfuerzos centran su atención en dicho colectivo, entre otros motivos, por la propia invisibilización de su sexualidad. Esto ocurre todavía más, cuando se trata de conductas penalizadas socialmente, como sería el caso de la infidelidad. Por este motivo, el presente estudio busca analizar la conducta de uso del preservativo en personas mayores, en el contexto de la infidelidad, así como el papel que podrían jugar variables psicológicas y nuevos contextos sexuales, como internet. Para ello, 244 personas (4…
Revista de psicodidáctica
2017
Título, resumen y palabras clave en español y en inglés Resumen basado en el de la publicación Existen evidencias de que el apoyo social de la familia, los iguales y el profesorado influye sobre la implicación escolar del alumnado, su éxito académico y satisfacción con la escuela. Se busca probar, mediante ecuaciones estructurales, los efectos del apoyo académico percibido y la implicación escolar sobre la satisfacción con la escuela. Se administra una batería de instrumentos a 2028 estudiantes de origen angoleño, con edades comprendidas entre 14 y 22 años (M = 17.4; DT = 2.3). Los resultados muestran la influencia que ejerce el apoyo académico percibido del profesorado, la familia y los ig…
Surfactant-assisted synthesis of Cd1−xCoxS nanocluster alloys and their structural, optical and magnetic properties
2010
We report the synthesis of Co-doped CdS nanoclusters (Cd1−xCoxS) for different doping concentrations (x = 0.10, 0.20 and 0.30) and characterization of their structural, optical, and magnetic properties. The structural properties studied by X-ray diffraction revealed hexagonal-greenockite structure and a decrease of the lattice parameters (a and c) with doping, showing incorporation of Co in the lattice. The morphology of the nanoclusters was studied by scanning electron microscopy. The optical absorption studies, using diffused reflectance spectroscopy, revealed that Co doping modifies the absorption band edge. Ferromagnetic phase was observed in the magnetization measurements at room-tempe…
Anomalous and normal Hall effect in hydrogenated amorphous Si prepared by plasma enhanced chemical vapor deposition
2010
The double sign anomaly of the Hall coefficient has been studied in p -doped and n -doped hydrogenated amorphous silicon grown by plasma enhanced chemical vapor deposition and annealed up to 500 °C. Dark conductivity as a function of temperature has been measured, pointing out a conduction mechanism mostly through the extended states. Anomalous Hall effect has been observed only in the as-deposited n -doped film, disappearing after annealing at 500 °C, while p -doped samples exhibit normal Hall effect. When Hall anomaly is present, a larger optical band gap and a greater Raman peak associated with Si-H bond are measured in comparison with the cases of normal Hall effect. The Hall anomaly wi…
Anion exchange membrane based on alkali doped poly(2,5-benzimidazole) for fuel cell
2012
Abstract The properties of alkali doped poly(2,5-benzimidazole) membrane with different alkali doping levels for fuel cell application are reported in this work. The alkali doping level played an important role for the ion conductivity of the membrane. The ion conductivity significantly increased with alkali doping level. The ion conductivity also increased with the temperature. The ion conductivity of the alkali doped ABPBI membrane (alkali doping level = 0.37), reached to 2.3 × 10 − 2 S cm − 1 at room temperature and 7.3 × 10 − 2 S cm − 1 at 100 °C. The water uptake of the alkali doped ABPBI membrane was increased from 9.1% to 19.2% with increasing alkali doping level at room temperatur…