Abdelmoty M. Ahmed  Reda Abo Alez  Gamal Tharwat  Muhammad Taha  B. Belgacem  Ahmad M. J. Al Moustafa 《成像科学杂志》2020,68(1):11-23

ABSTRACT

Arabic sign language (ArSL) is method of communication between deaf communities in Arab countries; therefore, the development of systemsthat can recognize the gestures provides a means for the Deaf to easily integrate into society. In this research we implemented a computational structurefor an intelligent interpreter that automatically recognizes the isolated dynamic gestures. The proposed system recognizes and translates gesturesperformed with one or both hands. It comprises five subsystems, building dataset, video processing, feature extraction, mapping between ArSL and Arabictext, and text generation. To apply the system, 100-signs of ArSL was used, which was applied on 1500 video files. It's were divided into five classes:alphabet, numbers, \"prepositions, pronouns and question words\", Arabic life expressions, and \"nouns and verbs\". The evaluation indicated that thesystem automatically recognizes and translates isolated dynamic ArSL gestures by highly accurate manner. The results showed that the system accuracy is 95.8%.  相似文献   

    

Ali I. Gardezi  Muhammad S. Karim  Joel E. Rosenberg  Julia J. Scialla  Tanushree Banerjee  Neil R. Powe  Tariq Shafi  Rulan S. Parekh  Alexander S. Yevzlin  Brad C. Astor 《Hemodialysis international. International Symposium on Home Hemodialysis》2020,24(1):43-51

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Zihe Cai  Shengxuan Lin  Jiajia Xiao  Tahir Muhmood  Yuhang Chen  Yifan Wang  Xiaobin Hu  Lirong Zheng 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(32)

Freestanding bifunctional electrodes with outstanding oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) properties are of great significance for zinc–air batteries, attributed to the avoided use of organic binder and strong adhesion with substrates. Herein, a strategy is developed to fabricate freestanding bifunctional electrodes from the predeposited nickel nanoparticles (Ni‐NCNT) on carbon fiber paper. The steric effect of monodispersed SiO₂ nanospheres limits the configuration of carbon atoms forming 3D interconnected nanotubes with uniformly distributed NiN₂ active sites. The bifunctional electrodes (Ni‐NCNT) demonstrate ideal ORR and OER properties. The zinc–air batteries assembled with Ni‐NCNT directly exhibit extremely outstanding long term stability (2250 cycles with 10 mA cm^?2 charge/discharge current density) along with high power density of 120 mV cm^?2 and specific capacity of 834.1 mA h g^?1. This work provides a new view to optimize the distribution of active sites and the electrode structure.  相似文献   

    

Riaz ur Rehman  Bakhtawar Khan  Tehmina Aziz  Faiza Zareen Gul  Syeda Nasreen  Muhammad Zia 《IET nanobiotechnology / IET》2020,14(5):423

Due to unique physiochemical properties, nanoparticles (NPs) have acquired substantial attention in the field of research. However, threats of ecotoxicity and phytotoxicity have limited their biological applications. In this study in vivo experiments were performed to determine the effect of CuO (12.5, 25 and 50 mg/kg) and ZnO (200, 400 and 600 mg/kg) NPs on growth, and antioxidant activities of Brassica nigra. The results showed that CuO NPs did not affect the seed germination while presence of ZnO NPs in the soil generated an inhibitory effect. Both CuO and ZnO NPs positively influenced the growth of stem and other physiological parameters i.e. stem height increased (23%) at 50 mg/kg CuO while root length decreased (up to 44%) with an increase in the concentration of NPs. Phytochemical screening of apical, middle and basal leaves showed elevated phenolic and flavonoid contents in the range of 15.3–59 μg Gallic Acid Equivalent (GAE)/mg Dry Weight (DW) and 10–35 μg Querceitin Equivalent (QE)/mg DW, respectively, in NPs‐treated plants. Antioxidant activity was higher in CuO NPs‐treated plants as compared to ZnO and control plants. Results conclude that CuO and ZnO NPs at low concentrations can be exploited as nanofertilisers in agriculture fields.Inspec keywords: biochemistry, enzymes, renewable materials, crops, nanoparticles, soil, nanofabrication, zinc compounds, organic compounds, agricultural products, toxicology, nanobiotechnologyOther keywords: antioxidative response, ZnO nanoparticles exposure, soil conditions, unique physiochemical properties, germination, antioxidant activities, brassica nigra plant, antioxidant activity, CuO NP‐treated plants, control plants, ZnO NPs effect, mass 15.3 mug to 59.0 mug, mass 10.0 mug to 35.0 mug, CuO, ZnO  相似文献   

    

Muhammad Imran Saleem  Shengyi Yang  Ruonan Zhi  Muhammad Sulaman  Perumal Veeramalai Chandrasekar  Yurong Jiang  Yi Tang  Attia Batool  Bingsuo Zou 《Advanced Materials Interfaces》2020,7(11)

All‐inorganic lead halide perovskites with good surface morphology show substantial prospect for optoelectronic devices. However, the anion exchange of coordinated alkylamine ligands (e.g., oleic acid and oleylamine) can detach ligands and induce more interface trap sites, subsequently to reduce device performance. In this paper, therefore, a simple solution‐processed route is presented to synthesize quasi coreshell CsPbBr₃formamidinium iodide (FAI = CH(NH₂)₂I) colloidal quantum dots (CQDs), and then it is applied as the active layer for photodetectors by finely controlling the ligands exchange. The presence of FAI = CH(NH₂)₂I on CsPbBr₃ is confirmed by Fourier transform infrared spectroscopy. As a result, the photodetector ITO/ZnO (100 nm)/CsPbBr₃ (150 nm)/Au show an enhanced specific detectivity over 10¹³ Jones with a responsivity of 19 A W¹ under 3 mW cm² 405 nm illumination at 1.5 V. The experimental data show that the enhanced device performance is due to the improved crystallinity and less surface defects of CsPbBr₃ CQDs, as the result of less alkylamine ligands is detached during its FAI passivation, thus the charge carriers' mobility of the film is improved. Therefore, it provides a promising way for high‐performance solution‐processed all‐inorganic CsPbBr₃ based optoelectronic devices.  相似文献   

    

Muhammad Rizaal  Kunihisa Nakajima  Takumi Saito  Masahiko Osaka  Koji Okamoto 《Journal of Nuclear Science and Technology》2020,57(9):1062-1073

ABSTRACT

The interaction of cesium hydroxide and a calcium silicate insulation material was experimentally investigated at high-temperature conditions to evaluate the possibility of unprecedented cesium retention under severe accident of boiling water reactor. The temperature where the interactions occurred and chemical species of cesium after the interaction were examined in this study. A thermogravimetry equipped with differential thermal analysis was used to analyze thermal events in the samples of mixed calcium silicate and cesium hydroxide under oxidizing and reducing atmospheric conditions with a maximum temperature of 1100°C. Before being mixed with cesium hydroxide, a part of calcium silicate was pretreated at high temperature to evaluate the effect of possible structural changes of this material due to a preceding thermal history and also for the sake of thermodynamic evaluation. It was found that for the original material, as xonotlite (Ca₆Si₆O₁₇(OH)₂) crystal, the endothermic reaction with cesium hydroxide occurred over the temperature range 575–730°C; meanwhile, for heat-treated material, which varied the crystal phase of original material to wollastonite (CaSiO₃), the interaction occurred over the temperature range 700–1100°C. The X-ray diffraction analyses have indicated that both types of calcium silicates regardless of the atmospheric conditions, cesium aluminum silicate, CsAlSiO₄, was formed with aluminum in the samples as an impurity or adduct. The insolubility of this formed cesium suggested the potency of cesium localization in the primary containment vessels on other structural materials that possess similar elements to that of calcium silicate insulation; hence, an effective decommissioning process could be developed.  相似文献   

    

Jun Hu  Xi Wang  Shaojun Li  Muhammad Asif  Peng Ding  Yongbo Su  Wuchang Ding  Feng Yang  Xiaojuan Chen  Zhi Jin 《国际射频与微波计算机辅助工程杂志》2020,30(5)

Stacked structure is a good solution to overcome the low output voltage swing provided by a single device. When several devices are stacked, the bandwidth and output power are multiple times higher. This article analyzes the small‐signal voltage gain of the stacked structure, deriving the gain expression of the high‐frequency model and simplified model. Based on the specific device parameter, the different small‐signal voltage gains between the two models are compared and the designed stacked structure is proved to obtain a flat gain at low frequencies below about 3 GHz. To our best knowledge, this is the first article to analyze the gain flatness of stacked structure with two equivalent circuit models. To verify the stacked theory, a pseudomorphic high‐electron‐mobility transistor（PHEMT） power amplifier (PA) is implemented using 0.25 μm Gallium arsenide (GaAs) technology. The PA achieves an ultra‐high bandwidth of 30 MHz to 3 GHz and a linear gain of 21 dB ± 1.5 dB. At a 16‐V drain bias voltage, a saturated output power of higher than 2 W and a peak power‐added efficiency (PAE) of 44.1% are attained.  相似文献   

    

Muhammad S. Khan  Syed A. Naqvi  Adnan Iftikhar  Sajid M. Asif  Adnan Fida  Raed M. Shubair 《国际射频与微波计算机辅助工程杂志》2020,30(9)

A compact four‐element multiple‐input‐multiple‐output (MIMO) antenna for ultra‐wideband (UWB) applications with WLAN band‐notched characteristics is proposed here. The proposed antenna has been designed to operate from 2 to 12 GHz while reject the frequencies between 4.9 to 6.4 GHz. The four antenna elements are placed orthogonal to attain the polarization diversity and high isolation. A thin stub connected to the ground plane is deployed as a LC notch filter to accomplish the rejected WLAN band in each antenna element. The mutual coupling between the adjacent elements is at least 17 dB while it has low indoor and outdoor envelop correlation (<0.45) and high gain with compact size of two boards, each measuring 50 × 25 mm². To validate the concept, the prototype antenna is manufactured and measured. The comparison of the simulation results showed good agreement with the measured results. The low‐profile design and compact size of the proposed MIMO antenna make it a good candidate for diversity applications desired in portable devices operating in the UWB region.  相似文献   

    

Shahzadi Noreen  Qurratulann Afza Gardner  Iram Fatima  Saima Sadaf  Muhammad Waheed Akhtar 《Proteomics. Clinical applications》2020,14(2)

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Muhammad Iqbal  Heiko Gimperlein  Omar Laghrouche  Khurshid Alam  M. Shadi Mohamed  Muhammad Abid 《International journal for numerical methods in engineering》2020,121(12):2727-2746

In this article, a study of residual based a posteriori error estimation is presented for the partition of unity finite element method (PUFEM) for three-dimensional (3D) transient heat diffusion problems. The proposed error estimate is independent of the heuristically selected enrichment functions and provides a useful and reliable upper bound for the discretization errors of the PUFEM solutions. Numerical results show that the presented error estimate efficiently captures the effect of h-refinement and q-refinement on the performance of PUFEM solutions. It also efficiently reflects the effect of ill-conditioning of the stiffness matrix that is typically experienced in the partition of unity based finite element methods. For a problem with a known exact solution, the error estimate is shown to capture the same solution trends as obtained by the classical L₂ norm error. For problems with no known analytical solutions, the proposed estimate is shown to be used as a reliable and efficient tool to predict the numerical errors in the PUFEM solutions of 3D transient heat diffusion problems.  相似文献