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41.
Muhammad Khatib Tan‐Phat Huynh Yunfeng Deng Yehu David Horev Walaa Saliba Weiwei Wu Hossam Haick 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(2)
A flexible and stretchable field‐effect transistor (FET) is an essential element in a number of modern electronics. To realize the potential of this device in harsh real‐world conditions and to extend its application spectrum, new functionalities are needed to be introduced into the device. Here, solution‐processable elements based on carbon nanotubes that empower flexible and stretchable FET with high hole‐mobility (µh ≈ 10 cm2 V?1 s?1) and relatively low operating voltages (<8 V) and that retain self‐healing properties of all FET components are reported. The device has repeatable intrinsic and autonomic self‐healing ability, namely without use of any external trigger, enabling the restoration of its electrical and mechanical properties, both after microscale damage or complete cut of the device—for example by a scissor. The device can be repeatedly stretched for >200 cycles of up to 50% strain without a significant loss in its electrical properties. The device is applicable in the form of a ≈3 µm thick freestanding skin tattoo and has multifunctional sensing properties, such as detection of temperature and humidity. With this unprecedented biomimetic transistor, highly sustainable and reliable soft electronic applications can be introduced. 相似文献
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We propose a modified linear parallel interference cancelation (PIC) structure using the adaptive minimum mean output-energy (MMOE) algorithm for direct-sequence code-division multiple-access (DS-CDMA) systems. The complexity of the proposed receiver structure is shown to be linear in the number of users and hence, lower complexity than the centralized minimum mean-squared error (MMSE) multiuser detector. It is demonstrated that the proposed receiver structure can significantly reduce the long training period required by the standard adaptive MMOE receiver in near-far environments. Both numerical and theoretical results show that the proposed receiver performs close to the optimum MMSE receiver whereas the conventional adaptive MMOE detector suffers from high BER’s due to the imperfect filter coefficients. Also our results show a three fold increase in the number of users when the MMOE-PIC is used relative to the conventional MMOE receiver. Furthermore, the transient behavior of the proposed MMOE-PIC receiver due to abrupt changes in the interference level is examined. It is shown that the proposed adaptive receiver offers much faster self recovery, with less signal-to-interference ratio (SIR) degradation, than the standard MMOE in sever near-far scenarios. 相似文献
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Doaa Gewily;Walaa Shalaby;Mohamed Abumandour;Om Prakash Choudhary;Ramadan Kandyel; 《Microscopy research and technique》2024,87(3):546-564
There is scanty data about the comparative morphological features between the pecten oculi of two carnivorous birds with different visual active clock hours: the diurnal common kestrel and the nocturnal little owl. This study illustrated the comparative gross, scanning electron microscopy, and histological characteristics between pecten oculi of kestrel and little owl. This study first attempts to describe the scanning electron microscopy-energy dispersive x-ray (SEM–EDX) elemental analysis at the parts (apex, middle, and base) of the pecten oculi of these two birds. The present study results observed the same position, origin, directions, parts, convoluted outer pleat surfaces, and SEM–EDX elemental analysis, but there were some minor variations due to the different visual active clock hours. These minor variations were summarized in the following points: pleat number (21–23 in the kestrel and 10–11 in the owl), shape (fan rhomboid in the kestrel and accordion in the owl), inter-pleat spaces (wider in the kestrel than in the owl), pigmentations (highly black pigmented in the owl than in the kestrel), hyalocyte cell aggregations (highest in the middle and dwindling at the apex and base in the kestrel, while highest in the middle and base and dwindling at the apex in the owl), and SEM–EDX elemental analysis percentage. SEM/EDX elemental analysis confirmed the presence of oxygen (the highest one), carbon, nitrogen (the second one), nitrogen (the third one), and aluminum (the lowest one) in varying percentages within the pecten oculi; these findings contribute to our understanding of its structural, adaptations with different visual active clock hours, and functional characteristics. 相似文献
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Jules Merlin Moualeu Walaa Hamouda Fambirai Takawira 《Wireless Communications and Mobile Computing》2016,16(16):2605-2618
Recently, cooperative relaying techniques have been integrated into spectrum‐sharing systems in an effort to yield higher spectral efficiency. Many investigations on such systems have assumed that the channel state information between the secondary transmitter and primary receiver used to calculate the maximum allowable transmit secondary user transmit power to limit the interference is known to be perfect. However, because of feedback delay from the primary receiver or the time‐varying properties of the channel, the channel information may be outdated, which is an important scenario to cognitive radio systems. In this paper, we investigate the impact of outdated channel state information for relay selection on the performance of partial relay selection with amplify and forward in underlay spectrum‐sharing systems. We begin by deriving a closed‐form expression for the outage probability of the secondary network in a Rayleigh fading channel along with peak received interference power constraint and maximum allowable secondary user transmit power. We also provide a closed‐form expression for the average bit‐error rate of the underlying system. Moreover, we present asymptotic expressions for both the outage probability and average bit‐error rate in the high signal‐to‐noise ratio regime that reveal practical insights on the achievable diversity gain. Finally, we confirm our results through comparisons with computer simulations. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Walaa F. Alsanie Sherin Abdelrahman Majid Alhomrani Ahmed Gaber Ebtisam Abdulah Alosimi Hamza Habeeballah Heba A. Alkhatabi Raed I. Felimban Charlotte A. E. Hauser Hossam H. Tayeb Abdulhakeem S. Alamri Abdulwahab Alamri Bassem M. Raafat Khaled A. Alswat Yusuf S. Althobaiti Yousif A. Asiri 《International journal of molecular sciences》2022,23(20)
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Muhammad Mahmoud El-Gharbawy Fatma Khalifa Gad Walaa Mahmoud Shehata 《Egyptian Journal of Petroleum》2021,30(1):11-15
Ammonia is an important industrial chemical, and its production is one of the highest of all inorganic chemicals. It is synthesized, in principal, from nitrogen and hydrogen by Haber process. It was found that the equilibrium constant (KP) of Haber reaction is strongly pressure dependent. Many correlations were developed in order to rigorously express this (KP); however, the most reliable expressions involved are inherently complex. This paper illustrates a simple correlation which was developed to express the value of (KP) of Haber reaction at temperatures from 350 to 600 °C and pressures from 50 to 300 atm, which covers today’s industrial range. In this correlation, KP is expressed in terms of temperature and pressure of equilibrium mixture which is the direct data measured. The effects of temperature and pressure are not separated allowing KP to be calculated directly, without iterations; using spreadsheet. Results were compared to that of Gillespie and Beattie method showing very good match. The new simple correlation can be used easily in commercial simulation packages, e.g. Hysys, using its embedded spreadsheet to build reliable ammonia synthesis reactor modeling benefiting from featured analysis methods of these packages. 相似文献
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Walaa Abdallah Vanessa Chirino Prof. Ian Wheeldon Prof. Scott Banta 《Chembiochem : a European journal of chemical biology》2019,20(14):1827-1837
The enzymatic microenvironment can impact biocatalytic activity; however, these effects can be difficult to investigate as mutations and fusions can introduce multiple variables and overlapping effects. The fusion of a supercharged protein is a potentially facile means to alter the enzymatic microenvironment. We have investigated complexes made between a thermostable alcohol dehydrogenase (AdhD) and superfolding green fluorescent protein (sfGFP) mutants with extreme surface charges. Three charged sfGFP variants, −30, 0, and +36 were covalently attached to AdhD through the SpyCatcher/SpyTag system. Specific rates for the NAD+-dependent oxidation of butane-2,3-diol were significantly increased in the −30 sfGFP complex, a mixed effect was seen for the 0 sfGFP complexes, and the rates were unaffected by +36 sfGFP complexation. Reactions performed at various pH values (7.8–9.8) and salt concentrations (7.75–500 mm ) showed that there was a complex interplay between these effects that was consistent with fusion proteins affecting the local ionic strength, as opposed to the local pH. Steady-state kinetic analyses were performed with the −30 and 0 AdhD–sfGFP complexes. The overall catalytic efficiency was dependent on the charge of the fused sfGFP variant; the −30 sfGFP fusions exhibited the largest beneficial effects at pH 8.8. The impact of the fusions on the apparent ionic strength provides further insight into the effects of charged patches observed on metabolon-forming enzyme complexes. 相似文献