Search results for "strength"
showing 10 items of 2415 documents
Room-temperature efficient light detection by amorphous Ge quantum wells
2013
In this work, ultrathin amorphous Ge films (2 to 30 nm in thickness) embedded in SiO2 layers were grown by magnetron sputtering and employed as proficient light sensitizer in photodetector devices. A noteworthy modification of the visible photon absorption is evidenced due to quantum confinement effects which cause both a blueshift (from 0.8 to 1.8 eV) in the bandgap and an enhancement (up to three times) in the optical oscillator strength of confined carriers. The reported quantum confinement effects have been exploited to enhance light detection by Ge quantum wells, as demonstrated by photodetectors with an internal quantum efficiency of 70%. © 2013 Cosentino et al.
Sedimentation of halloysite nanotubes from different deposits in aqueous media at variable ionic strengths
2019
Abstract Halloysite clay is a natural nanomaterial that is attracting a growing interest in colloidal science. The halloysite aqueous dispersion stability is a key aspect for the configuration of a purification protocol as well as to establish the durability of a formulation. A physico-chemical study demonstrated the role of ionic strength and nanotube characteristic sizes on the sedimentation behavior. We highlighted the importance of the electrostatic repulsions exercised between the particles in the settling process. A protocol for image analysis has been proposed to provide robust information from time resolved optical images on the suspensions. In conclusion, we managed to correlate mi…
INNOVATIVE PERFORMANCE AND INNOVATION SYSTEM OF LATVIA
2021
The research andanalysis of strengths and weaknesses of national innovation system is extremelyimportant to successful and efficient innovation support policymaking.Innovation support policies should take into consideration all specifies ofnational innovation system in the country, not being one-size-fits-all. Untilnow, little analysis on the Latvian innovation system was made. The paper aimsto show Latvian innovative performance and to propose factors forwell-functioning innovation system of Latvia. This research gives apossibility to researchers and policy-makers to investigate the mismatchbetween policies and problems and identify policy gaps. KEY WORDS: innovativeperformance, innovation…
Modelling of natural and synthetic polyelectrolyte interactions in natural waters.
2006
In this paper SIT and Pitzer models are used for the first time to describe the interactions of natural and synthetic polyelectrolytes in natural waters. Measurements were made potentiometrically at 25 °C in single electrolyte media, such as Et4NI and NaCl (for fulvic acid 0.1 < I /mol L− 1 < 0.75), and in a multi-component medium simulating the composition of natural waters at a wide range of salinities (for fulvic and alginic acids: 5 < S < 45) with particular reference to sea water [Synthetic Sea Water for Equilibrium studies, SSWE]. In order to simplify calculations, SSWE was considered to be a “single salt” BA, with cation B and anion A representing all the major cations (Na+, K+, Mg2+…
Modeling the sorption of Np(V) on Na-montmorillonite – effects of pH, ionic strength and CO2
2019
Abstract Results from batch type experiments were modeled using the 2 SPNE SC/CE model developed by Bradbury and Baeyens. This work focused on the applicability of this model to the sorption of Np(V) on Na-montmorillonite under high saline conditions (0.1–3.0 M NaCl) in the pH range of 2–10 and in the presence of dissolved CO2 (p(CO2) = 10−3.3 atm). Under ambient air conditions two additional surface complexation species had to be taken into account, which are ternary species involving one carbonate ligand (≡SONpO2(CO3)2−, ≡SONpO2(CO3)Na−). The gained set of complexation parameters was successfully tested over a wide range of Np(V) concentrations (10−4 to 10−12 M) under Ar atmosphere and am…
Motor Conduction Studies and Handgrip in Hereditary TTR Amyloidosis: Simple Tools to Evaluate the Upper Limbs
2022
PurposeHereditary transthyretin amyloidosis with polyneuropathy (ATTRv) is caused by mutations in the TTR gene, leading to misfolded monomers that aggregate generating amyloid fibrils. The clinical phenotype is heterogeneous, and characterized by a multisystemic disease affecting the sensorimotor and autonomic functions along with other organs.Materials and MethodsAll the patients were assessed by complete neurological assessment, neurophysiological evaluation, of the median nerve, and handgrip analysis. The data are presented as means and standard deviations. Parametric and non-parametric assessments have been performed to identify differences between groups. Pearson's correlation has been…
Hypertrophic adaptations of lower limb muscles in response to three different resistance training regimens
2020
Introduction: The research tested the effects of training in three different load zones. The hypothesis is that this type of training can provide more complete hypertrophic gains compared to workouts performed in a specific, single load area. Materials and methods: 37 participants were divided into 4 groups (SE; S; E; C). The first group trained simultaneously with high loads and low repetitions and with low loads and high repetitions; the second group trained in the high load condition, the third with low loads and high repetitions brought to the point of fatigue and the last control group had not practiced any type of training. The participants performed the training program 3 times a wee…
Force normalization in paraplegics.
2012
The principal aim of our study was the determination of the effectiveness of a standardized ratio, allometric scaling model and a gamma function model in normalizing the isometric torque data of spinal cord patients and healthy subjects. For this purpose we studied a sample of 21 healthy males and 23 spinal cord injury males. The experiment consisted of the measurement of the force of the upper limb movement executed by all the subjects. We also determined anthropometric variables with dual-energy x-ray absorptiometry. The experimental data were analyzed with 3 force normalization methods. Our results indicate that the most important confounding variable was the fat free mass of the dominan…
Untersuchung der Feldelektronenemission und ihrer Temperaturabh�ngigkeit bei Stromst�rken zwischen 10?14 und 10?19 A
1964
The field emission of a tungsten point cathode at very low emission currents was investigated by means of a secondary emission multiplier. The validity of the Fowler-Nordheim equation was experimentally confirmed within the range from 10−8 to 10−19 A. The dependence of the total emission current on temperature and electrical field strength was measured in the transition region between thermionic and field emission. A comparison is drawn with the theory ofMurphy andGood.
Mechanical properties of nanostructured carbon layers grown by CVD and PLD techniques
2010
Pulsed laser deposition (PLD) and chemical vapour deposition (CVD) have been proven to be among the most successful techniques for growing the entire spectrum of carbon films, which can be used in a wide range of technical applications. Here an investigation has been performed to explore the effect of different growing techniques (PLD and CVD) and process parameters (such as deposition time and substrate type) on the films' morphology and mechanical properties. The mechanical properties of the grown thin films were characterised by means of nano/micro indentation and scratch test techniques. It was observed that the thickness of the Al2O3 interlayer (between the Fe catalyst nanoparticles an…