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81.
Effat Sitara Habib Nasir Asad Mumtaz Muhammad Fahad Ehsan Manzar Sohail Sadia Iram Syeda Aqsa Batool Bukhari Sharif Ullah Tehmina Akhtar Azhar Iqbal 《International Journal of Hydrogen Energy》2021,46(50):25424-25435
The objective of this research is to construct a type-II heterojunction interface for effective photoelectrochemical (PEC) water splitting for hydrogen generation. A series of ZnSe/g-C3N4 heterojunctions is prepared by ultrasonication procedure and tested for PEC water splitting for the first time. The successful formation of ZnSe/g-C3N4 is confirmed by phase, morphological and optical analysis. Linear sweep voltammetry of 0.05 ZG (0.05% ZnSe/g-C3N4) showed a six-fold higher photocurrent density of 500 μA than g-C3N4. These results are supported by the Tafel slopes and PL (photoluminescence spectroscopy) studies by showing the smallest slope and lesser electron-hole recombination for 0.05 ZG. Increased lifetime of 107 ms and a higher donor density of 3.6 × 1019 cm?3 for 0.05 ZG is observed. The smallest semicircle for 0.05 ZG in EIS implies the least charge transfer resistance among the prepared heterojunctions. All the results comply with each other showing the successful formation of type-II heterojunction for enhanced PEC water splitting. 相似文献
82.
Haroon Rehman;Mohammad Fahad;Adil Sarwar;Mohd Tariq;Chang-Hua Lin; 《International Journal of Circuit Theory and Applications》2024,52(2):598-617
In the power electronics industry, reliability is of utmost importance to manufacturers. Power semiconductor devices are extensively utilized in multilevel inverters (MLIs), which results in increased failure probability. MLI structures have a significant impact on the system's overall reliability. MLIs with a high degree of reliability reduce system maintenance costs and improve efficiency and the life of the entire system. This paper presents a comprehensive evaluation of five-level packed U-cell (PUC5) inverter, modified five-level PUC (MPUC5) inverter, and their fault-tolerant (FT) variants with respect to reliability, degree of fault tolerance, power loss and efficiency, and cost. A more accurate reliability evaluation method is used in this work in which failure rates of each component of inverter topologies under healthy and post-fault conditions are calculated. Hence, this method provides more accurate reliability function of an MLI topology as compared to other methods in which failure rates are assumed to be same for all switches. Typhoon HIL-402 emulator is used to demonstrate the FT capabilities of topologies in hardware-in-the-loop (HIL) environments. 相似文献
83.
Shah Fahad;Song Li;Yufei Zhai;Cong Zhao;Zoe Pikramenou;Min Wang; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(3):2304237
Recent chronological breakthroughs in materials innovation, their fabrication, and structural designs for disparate applications have paved transformational ways to subversively digitalize infrared (IR) thermal imaging sensors from traditional to smart. The noninvasive IR thermal imaging sensors are at the cutting edge of developments, exploiting the abilities of nanomaterials to acquire arbitrary, targeted, and tunable responses suitable for integration with host materials and devices, intimately disintegrate variegated signals from the target onto depiction without any discomfort, eliminating motional artifacts and collects precise physiological and physiochemical information in natural contexts. Highlighting several typical examples from recent literature, this review article summarizes an accessible, critical, and authoritative summary of an emerging class of advancement in the modalities of nano and micro-scale materials and devices, their fabrication designs and applications in infrared thermal sensors. Introduction is begun covering the importance of IR sensors, followed by a survey on sensing capabilities of various nano and micro structural materials, their design architects, and then culminating an overview of their diverse application swaths. The review concludes with a stimulating frontier debate on the opportunities, difficulties, and future approaches in the vibrant sector of infrared thermal imaging sensors. 相似文献
84.
A smart grid is an electricity network, which deals with electronic power conditioning and control of production, transmission, and distribution of electrical power by employing digital communication technologies to monitor and manage local changes in electricity usage. In the traditional power grid, energy consumers remain oblivious to their power consumption patterns, resulting in wasted energy as well as money. This issue is severely pronounced in the developing countries where there is a huge gap between demand and supply, resulting in frequent power outages and load‐shedding. For electrical energy savings, the smart grid employs demand side management (DSM), which refers to adaptation in consumer's demand for energy through various approaches such as financial incentives and awareness. The DSM in future smart grid must exploit automated energy management systems (EMS) built upon the state‐of‐the‐art technologies such as the internet of things (IoT) and cloud and/or fog computing. In this paper, we present the architecture framework, design, and implementation of an IoT and cloud computing‐based EMS, which generates load profile of consumer to be accessed remotely by utility company or by the consumer. The consumers' load profiles enable utility companies to regulate and disseminate their incentives and incite the consumers to adapt their energy consumption. Our designed EMS is implemented on a Project Circuit Board (PCB) to be easily installed at the consumer premises where it performs the following tasks: (a) monitors energy consumption of electrical appliances by means of our designed current and voltage sensors, (b) uploads sensed data to Google Firebase cloud over many‐to‐many IoT communication protocol Message Queuing Telemetry Transport (MQTT) where consumer's load profile is generated, which can be accessed via a web portal. These load profiles serve as input for implementing the various DSM approaches. Our results demonstrate generated load profiles of consumer load in terms of current, voltage, energy, and power accessible via a web portal. 相似文献
85.
This work reports the synthesis of a series of reactor blends of linear and branched polyethylene materials using a combination of [1,4‐bis(2,6‐diisopropylphenyl) acenaphthene diimine nickel(II) dibromide] ( 1 )/MMAO, known as an active catalyst for the production of branched polyethylene, and [rac‐ethylenebis(indenyl) zirconium dichloride] ( 2 )/MMAO, which is active for the production of linear polyethylene. The polymerization runs were performed at various levels of temperature, pressure, and catalyst 2 molar fractions. At 5°C, there was very low influence of catalyst 2 molar fraction on the overall catalyst activity. However, at 30°C and 50°C, the overall catalyst activity increased linearly with catalyst 2 molar fraction. The same linear dependency was also found for the polymerization reactions carried out at 60°C and 100°C. At various levels of temperature and ethylene pressure, higher melting temperature and crystallinity were observed with an increase in catalyst 2 molar fraction. At 60°C and 100 psig, the DSC thermograms of the polymers produced with 1 / 2 /MMAO exhibited two distinct peaks with melting temperatures closely corresponding to the melting temperatures of the polymers produced with the individual catalysts, 1 /MMAO and 2 /MMAO. The GPCV analysis of all polyethylene samples showed monomodal molecular weight distributions with low polydispersities. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2212–2217, 2005 相似文献
86.
87.
In this study, differential evolution was employed to perform optimization of a heliostat field. A complete mathematical code was developed for this purpose, which generates a heliostat field and calculates the optimum spacing between heliostats through differential evolution optimization technique. The optimization was executed for two sets of two cases and compared with an un‐optimized case. In the first case, only the optical performance was optimized, whereas in the second case, the normalized ratio of the optical performance to the land area covered by the heliostat field was maximized. In the first set of cases, the extra security distance between the heliostats was neglected, whereas in the second set of cases, the extra security distance was taken into account. To apply and examine the application of the optimization algorithm developed, 3 days of the year were selected: March 21, June 21, and December 21, considering Dhahran, Saudi Arabia as an illustrative example. For June 21, when the extra security distance between the heliostats is neglected, the optical efficiency of the un‐optimized case was 0.6026, while for the first optimized case, it was 0.6395, and for the second optimized case, it was 0.6033. However, when the extra security distance was considered, the optical efficiency of the un‐optimized case was 0.6167; while for the first optimized case, it was 0.6241, and for the second optimized case, it was 0.6167. Similar observations were realized for the other cases selected. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
88.
Shuanghui Wu 《电力系统保护与控制》2017,2(3):220-228
The foremost issues of 21st century are challenging demand of electrical energy and to control the emission ofGreen House Gases (GHG) emissions. Renewable energy resources based sustainable microgrid emerges as one ofthe best feasible solution for future energy demand while considering zero carbon emission, fossil fuelindependency, and enhanced reliability. In this paper, optimization and implementation of institutional basedsustainable microgrid are discussed based on cost analysis, carbon emission, and availability of energy resources.Various microgrid topologies are considered for addressing the most ideal solution. The metrological data such asirradiance is acquired from solar satellite data of NASA (National Aero Space Agency) while the data for wind speedis taken from synergy enviro engineer’s site. HOMER® simulation tool is used for modelling and optimizationpurpose. 相似文献
89.
Instruments and Experimental Techniques - Four-point probe (FPP) systems are essential to accurately measure the sheet resistance of various materials especially thin films. In this work, a simple... 相似文献
90.
Fahad S. Al-Mubaddel Rawesh Kumar Mahmud Lanre Sofiu Francesco Frusteri Ahmed Aidid Ibrahim Vijay Kumar Srivastava Samsudeen Olajide Kasim Anis Hamza Fakeeha Ahmed Elhag Abasaeed Ahmed I. Osman Ahmed Sadeq Al-Fatesh 《International Journal of Hydrogen Energy》2021,46(27):14225-14235
The increasing alarm of global warming always draws interest in reactions like dry reforming of methane (DRM) where both global warming gases (CO2 and CH4) are converted into value-added chemical building blocks, such as syngas. Nickel catalyst active sites along with support acid-base profiles play a key role in DRM. Herein, xLa2O3+(100-x) Al2O3 (x = 0, 10, 15, 20%) supports are prepared and followed by NiO dispersion over the produced support by impregnation method. It was tested for DRM reaction and characterized with TGA, XRD, TEM, IR, Surface area and porosity measurement, H2-TPR, CO2-TPD and NH3-TPD techniques. Upon increasing the basic lanthana proportion in the acidic alumina support, the crystallinity of alumina and acidity of total support decline. Up to 15% Lanthana addition in support claims a low acid and rich basic surface including super basic sites (related to unidentate carbonates) which governed optimum catalytic performance 64% CH4 conversion, 79% CO2 conversion and H2/CO ~ 1 up to 460-min in time on stream test. 20% lanthanum oxide loading led to inferior performance due to rapid loss of surface area, pore-volume, pore diameter, acidity and medium basic strength sites. Fine-tuning of acid-base lanthana-alumina support with dispersed Ni species are a means for understanding DRM. 相似文献