Search results for "electronic device"
showing 10 items of 55 documents
Surface structure promoted high-yield growth and magnetotransport properties of Bi2Se3 nanoribbons
2019
AbstractIn the present work, a catalyst-free physical vapour deposition method is used to synthesize high yield of Bi2Se3 nanoribbons. By replacing standard glass or quartz substrates with aluminium covered with ultrathin porous anodized aluminium oxide (AAO), the number of synthesized nanoribbons per unit area can be increased by 20–100 times. The mechanisms of formation and yield of the nanoribbons synthesized on AAO substrates having different arrangement and size of pores are analysed and discussed. It is shown that the yield and average length of the nanoribbons can base tuned by adjustment of the synthesis parameters. Analysis of magnetotransport measurements for the individual Bi2Se3…
Hybrid perovskites for light-emitting and photovoltaic devices
2017
El objetivo de esta tesis es el desarrollo de métodos y materiales apropiados para la preparación de capas delgadas de perovskitas híbridas, y su implementación en dispositivos optoelectrónicos. Se dedicará particular atención a las relaciones entre la naturaleza del material, el método de deposición y las propiedades optoelectrónicas. El trabajo está organizado como sigue: - Células solares de perovskitas preparadas por evaporación flash. Se desarrolla un simple método de evaporación por la preparación de células solares. - Dispositivos de perovskita con alta eficiencia fotovoltaica y electroluminiscente. En este capítulo se presentan dispositivos optoelectrónicos de perovskitas preparados…
Jump Height from Inertial Recordings : A Tutorial for a Sports Scientist
2019
Jump performance provides meaningful information both for sporting and clinical needs. Current state-of-the-art in jump performance assessment is laboratory-bound, however, out-of-the-laboratory methods are desirable. Therefore, the purposes of the present investigation were 1) to explore whether utilising a novel analytical approach minimises the bias between inertial recording unit (IMU)-based and jump mat-based jump height estimates, and 2) to provide a thorough tutorial for a sport scientist (see appendix) to facilitate standardisation of jump height estimation. Forty one women, men and boys aged 6 to 77 years-of-age completed three maximal counter movement jumps without arm swing, whic…
Portable PSG for sleep stage monitoring in sports: Assessment of SOMNOwatch plus EEG.
2019
Current sport-scientific studies mostly neglect the assessment of sleep architecture, although the distribution of different sleep stages is considered an essential component influencing an athlete's recovery and performance capabilities. A mobile, self-applied tool like the SOMNOwatch plus EEG might serve as an economical and time-friendly alternative to activity-based devices. However, self-application of SOMNOwatch plus EEG has not been validated against conventional polysomnography (PSG) yet. For evaluation purposes, 25 participants (15 female, 10 male;
Lead-Related Infective Endocarditis in Latvia: A Single Centre Experience
2019
Background and Objectives: Over the last five decades cardiac implantable electronic devices (CIED) have become established as the mainstay for the treatment of permanent bradycardias, chronic heart failure and dangerous heart rhythm disturbances. These devices improve survival and quality of life in many patients. However, infections associated with CIED implantation, particularly lead-related infective endocarditis (LRIE), can offset all benefits and make more harm than good for the patient. To date, there are no other studies in Latvia, addressing patients with lead-related infective endocarditis. The objective of this study was to identify the most common pathogens associated with LRIE …
Absolute Accelerometer-Based Intensity Prescription Compared to Physiological Variables in Pregnant and Nonpregnant Women
2020
Estimation of the intensity of physical activity (PA) based on absolute accelerometer cut points (Cp) likely over- or underestimates intensity for a specific individual. The purpose of this study was to investigate the relationship between absolute moderate intensity Cp and the first ventilatory threshold (VT1). A group of 24 pregnant and 15 nonpregnant women who performed a submaximal incremental walking test with measures of ventilatory parameters and accelerations from three different accelerometers on the wrist (ActiGraph wGT3X-BT, GENEActiv, Axivity AX3) and one on the hip (Actigraph wGT3X-BT) were analyzed. Cp were determined corresponding to 3 metabolic equivalents of task (MET), usi…
High-efficiency silicon-compatible photodetectors based on Ge quantum dots
2011
We report on high responsivity, broadband metal/insulator/semiconductor photodetectors with amorphous Ge quantum dots (a-Ge QDs) as the active absorbers embedded in a silicon dioxide matrix. Spectral responsivities between 1-4 A/W are achieved in the 500-900 nm wavelength range with internal quantum efficiencies (IQEs) as high as ∼700%. We investigate the role of a-Ge QDs in the photocurrent generation and explain the high IQE as a result of transport mechanisms via photoexcited QDs. These results suggest that a-Ge QDs are promising for high-performance integrated optoelectronic devices that are fully compatible with silicon technology in terms of fabrication and thermal budget. © 2011 Amer…
Lateral Fusion of Chemical Vapor Deposited N = 5 Armchair Graphene Nanoribbons
2017
Bottom-up synthesis of low-bandgap graphene nanoribbons with various widths is of great importance for their applications in electronic and optoelectronic devices. Here we demonstrate a synthesis of N = 5 armchair graphene nanoribbons (5-AGNRs) and their lateral fusion into wider AGNRs, by a chemical vapor deposition method. The efficient formation of 10- and 15- AGNRs is revealed by a combination of different spectroscopic methods, including Raman and UV−visnear-infrared spectroscopy as well as by scanning tunneling microscopy. The degree of fusion and thus the optical and electronic properties of the resulting GNRs can be controlled by the annealing temperature, providing GNR films with o…
Batteries for Aerospace: A Brief Review
2018
This paper presents a brief overview on batteries for aerospace application. In particular, More Electric Aircraft (MEA) and All Electric Aircraft (AEA) concepts are introduced at first, together with their main advantages and drawbacks. Subsequently, opportunities and issues related to the employment of batteries on aircrafts are presented and briefly discussed. Reference is then made to aircraft power system architectures and battery technologies, as well as on the state-of-the-art of battery management systems, state-of-charge and state-of-health estimations, and thermal management.
Wearable electromyography recordings during daily life activities in children with cerebral palsy.
2020
To test whether wearable textile electromyography (EMG) recording systems may detect differences in muscle activity levels during daily activities between children with cerebral palsy (CP) and age-matched typically developing children.Wearable textile EMG recording systems were used to obtain leg muscle activity in 10 children with spastic CP (four females, six males; mean age 9y 6mo, standard deviation [SD] 2y 4mo, range: 6-13y; Gross Motor Function Classification System [GMFCS] level I and II) and 11 typically developing children (four females, seven males; mean age 9y 9mo, SD 1y 11mo, 7-12y) at rest and while performing seven daily activities.Children with CP showed significantly lower a…