Chapter Sleep Spindles – As a Biomarker of Brain Function and Plasticity

Alternative & renewable energy sources & technolog

Sleep Spindles – As a Biomarker of Brain Function and Plasticity

Alternative & renewable energy sources & technolog

Long-term stability of transparent n/p ZnO homojunctions grown by rf-sputtering at room-temperature

ZnO-based n/p homojunctions were fabricated by sputtering from a single zinc nitride target at room temperature on metal or ITO-coated glass and Si substrates. A multi-target rf-sputtering system was used for the growth of all oxide films as multilayers in a single growth run without breaking the vacuum in the growth chamber. The nitrogen-containing films (less than 1.5 at.% of nitrogen) were n-type ZnO when deposited in oxygen-deficient Ar plasma (10% O2) and p-type ZnO when deposited in oxygen-rich Ar plasma (50% O2). The all-oxide homojunction ITO/n-ZnO/p-ZnO/ITO/glass was fabricated in a single deposition run and exhibited visible transparency in the range of 75–85%. The n/p ZnO homojunctions, having metallic contacts, formed on conventionally processed substrates showed a fairly unstable behavior concerning the current-voltage characteristics. However, the same homojunctions formed on Si3N4-patterned substrates and stored in atmosphere for a period of five months were stable exhibiting a turn-on voltage of around 1.5 V. The realization of a room temperature sputtered transparent and stable ZnO homojunction paves the way to the realization of all-oxide transparent optoelectronic devices

E-Government in the Arabian Gulf: A Vision toward Reality

This paper presents a review of e-government initiatives in the Arabian Gulf, where extensive efforts are being made to capitalize on the cyber technologies in order to enhance the government to citizen service. The described cases are from Kuwait, Bahrain, Saudi Arabia, Qatar, the United Arab Emirates and Oman,. While the efforts vary in size and intensity, what appears to be common is the top level support the e-government initiatives are receiving, which offers them visibility and hopefully warrants their eventual success

Real-world study for the optimal charging of electric vehicles

Electric Vehicles (EVs), accompanied with the use of Renewable Energy Sources (RES), are the solution for the decarbonization of the transport sector and are undoubtedly on the rise. Although EVs have been in the limelight over the last decade, little effort has been made towards the proper use of the vehicle's battery. Therefore, a better understanding of Lithium-ion (Li-ion) batteries, since they represent the heart of the majority of electric cars, during the discharging and charging procedure is crucial. The present study, that was experimentally conducted under real-world driving conditions, quantitatively analyzes the energy losses that take place during the charging of a Battery Electric Vehicle (BEV), focusing especially in the previously unexplored 80%-100% State of Charge (SoC) area. The results show that losses, during charging within the abovementioned area, are almost double compared to the 20%-80% SoC area and vehicle's average specific real energy consumption is almost 2 kWh/100 km more, compared to what the driver sees on the EV's dashboard. Furthermore, it is not for the driver's benefit to exceed 80% of SoC during charging, considering the required charging time, the distance that each SoC area provides and the life expectancy of the battery itself. Based on these results and after a thorough literature review, the authors suggest the optimum SoC range within which drivers should operate the EV's battery

An intra-K-complex oscillation with independent and labile frequency and topography in NREM sleep

NREM sleep is characterized by K-complexes (KCs), over the negative phase of which we identified brief activity in the theta range. We recorded high resolution EEG of whole-night sleep from 7 healthy volunteers and visually identified 2nd and 3rd stage NREM spontaneous KCs. We identified 3 major categories: a) KCs without intra-KC-activity (iKCa), b) KCs with non-oscillatory iKCa, and c) KCs with oscillatory iKCa. The latter group of KCs with intra-KC-oscillation (iKCo), was clustered according to the duration of the iKCo. iKCa was observed in most KCs (1150/1522, 75%). iKCos with 2, 3 and 4 waves were observed in 52% (786/1522) of KCs in respective rates of 49% (386/786), 44% and 7%. Successive waves of iKCos showed on average a shift of their maximal amplitude in the anterio-posterior axis, while the average amplitude of the slow KC showed no spatial shift in time. The iKCo spatial shift was accompanied by transient increases in instantaneous frequency from the theta band towards the alpha band, followed by decreases to upper theta. The study shows that the KC is most often concurrently accompanied by an independent brief iKCo exhibiting topographical relocation of amplitude maxima with every consecutive peak and transient increases in frequency. The iKCo features are potentially reflecting arousing processes taking place during the KC