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Progress in Natural Science:Materials International 2017年第5期27卷 606-614页

作者： M.Penchal Reddy R.A.Shakoor Gururaj Parande Vyasaraj Manakari f.ubaid A.M.A.Mohamed Manoj Gupta Center for Advanced Materials Qatar University Department of Mechanical Engineering National University of Singapore Department of Metallurgical and Materials Engineering Suez University

In the present study, nano-sized SiC(0, 0.3, 0.5, 1.0 and 1.5 vol%) reinforced aluminum(Al) metal matrix composites were fabricated by microwave sintering and hot extrusion techniques. The structural(XRD, SEM),mechanical(nanoindentation, compression, tensile) and thermal properties(co-efficient of thermal expansionCTE) of the developed Al-SiC nanocomposites were studied. The SEM/EDS mapping images show a homogeneous distribution of SiC nanoparticles into the Al matrix. A significant increase in the strength(compressive and tensile) of the Al-SiC nanocomposites with the addition of SiC content is observed. However,it is noticed that the ductility of Al-SiC nanocomposites decreases with increasing volume fraction of SiC. The thermal analysis indicates that CTE of Al-SiC nanocomposites decreases with the progressive addition of hard SiC nanoparticles. Overall, hot extruded Al 1.5 vol% SiC nanocomposites exhibited the best mechanical and thermal performance as compared to the other developed Al-SiC nanocomposites.

关键词： Al-SiC nanocomposites Microwave sintering Hot extrusion Mechanical properties Thermal expansion

Rapid post-earthquake safety assessment of low-rise reinforced concrete structures

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Earthquake Engineering and Engineering Vibration 2025年第1期24卷 101-112页

作者： Koji Tsuchimoto Yasutaka Narazaki Billie f.Spencer,Jr. International Design Division Design DepartmentTaisei CorporationTokyo 163-0606Japan Zhejiang University–University of Illinois Urbana-Champaign Institute Zhejiang UniversityHaining 314400China Civil and Environmental Engineering University of Illinois Urbana-ChampaignUrbana 61821USA

Many countries throughout the world have experienced large earthquakes,which cause building damage or *** such earthquakes,structures must be inspected rapidly to judge whether they are safe to *** facilitate the inspection process,the authors previously developed a rapid building safety assessment system using sparse acceleration measurements for steel framed *** proposed system modeled nonlinearity in the measurement data using a calibrated simplified lumped-mass model and convolutional neural networks(CNNs),based on which the buildinglevel damage index was estimated rapidly after *** proposed system was validated for a nonlinear 3D numerical model of a five-story steel building,and later for a large-scale specimen of an 18-story building in Japan tested on the E-Defense shaking ***,the applicability of the safety assessment system for reinforced concrete(RC)structures with complex hysteretic material nonlinearity has yet to be explored;the previous approach based on a simplified lumpedmass model with a Bouc-Wen hysteretic model does not accurately represent the inherent nonlinear behavior and resulting damage states of RC *** study extends the rapid building safety assessment system to low-rise RC moment resisting frame structures representing typical residential apartments in ***,a safety classification for RC structures based on a damage index consistent with the current state of practice is ***,a 3D nonlinear numerical model of a two-story moment frame structure is created.A simplified lumped-mass nonlinear model is developed and calibrated using the 3D model,incorporating the Takeda degradation model for the RC material *** model is used to simulate the seismic response and associated damage sensitive features(DSf)for random ground *** resulting database of responses is used to train a convolutional neural network(CNN)that performs rapid safety ***

关键词： rapid post-earthquake safety assessment acceleration interstory drift angle damage sensitive feature convolutional neural network RC structure simplified non-linear analysis model Takeda degradation model

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Energy Meteorology for the Evaluation of Solar farm Thermal Impacts on Desert Habitats

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ADVANCES IN ATMOSPHERIC SCIENCES 2025年第2期42卷 313-326页

作者： Coimbra, Carlos f. M. Univ Calif San Diego Ctr Excellence Renewable Resource Integrat Jacobs Sch Engn Dept Mech & Aerosp Engn La Jolla CA 92093 USA Univ Calif San Diego Ctr Energy Res La Jolla CA 92093 USA

This work addresses challenges and opportunities in the evaluation of solar power plant impacts, with a particular focus on thermal effects of solar plants on the environment and vice-versa. Large-scale solar power plants are often sited in arid or desert habitats, which tend to include fauna and flora that are highly sensitive to changes in temperature and humidity. Our understanding of both shortwave (solar) and longwave (terrestrial) radiation processes in solar power plants is complete enough to render the modeling of radiation fluxes with high confidence for most applications. In contrast to radiation, the convective environment in large-scale solar power plants is much more difficult to characterize. Wind direction, wind speed, turbulence intensity, dust concentration, ground condition, panel configuration density, orientation and distribution throughout the solar field, all affect the local environment, the balance between radiation and convection, and in turn, the performance and thermal impact of solar power plants. Because the temperatures of the two sides of photovoltaic (PV) panels depend on detailed convection-radiation balances, the uncertainty associated with convection affects the heat and mass transfer balances as well. Those balances are critically important in estimating the thermal impact of large-scale solar farms on local habitats. Here we discuss outstanding issues related with these transfer processes for utility-scale solar generation and highlight potential pathways to gain useful knowledge about the convective environment directly from solar farms under operating conditions. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic). (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)

关键词： environmental impact solar farms thermal balances shortwave and longwave radiation convection (sic)(sic)(sic)(sic) (sic)(sic)(sic)(sic)(sic)(sic) (sic)(sic)(sic) (sic)(sic)(sic)(sic)(sic)(sic)(sic) (sic)(sic)

Magnitude, spatial patterns and drivers of methane fluxes from coastal salt marshes and mangrove forests in China

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Science China Earth Sciences 2025年第3期68卷 850-866页

作者： Yixuan YU Derrick Y.f.LAI Minjie HU Chuan TONG Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education Fujian Normal University School of Geographical Sciences Fujian Normal University Department of Geography and Resource Management The Chinese University of Hong Kong

Methane（CH4） is a highly potent greenhouse gas due to its high radiative forcing and global warming *** the magnitude, spatial patterns, and drivers of CH4emission from wetlands at the regional scale is crucial for formulating suitable strategies to mitigate future climate change. In this study, we synthesized the CH4flux data reported for major plant communities in the coastal salt marshes and mangrove forests in China and produced a spatial map of CH4fluxes from the mangrove sediments and salt marshes in China based on the results of machine learning models. Moreover, we examined the main drivers of CH4flux from these coastal wetlands and estimated the annual CH4emissions from the salt marshes and mangrove forests in different coastal provinces of China using a bottom-up approach. Our results showed that the mean CH4fluxes from the salt marsh and mangrove ecosystems in China were 2.22±0.29 and 2.26±0.55 mg m-2h-1, respectively. Across China, the total annual CH4emission from salt marshes was 31,179.75 Mg CH4a-1, while that from mangroves was 5,533.97 Mg CH4a-1with the sediments contributing to 12.7%(701.64 Mg CH4a-1) of the total efflux. The salt marshes and mangroves in China accounted for 2.75% and 0.14%–0.15% of the global annual CH4emissions from these two ecosystems,respectively. Moreover, we found that CH4emissions from the salt marshes and mangroves could offset the cooling impact arising from net carbon dioxide uptake by 88% and 53%, respectively, over a 100-year time scale. Mean annual temperature, soil moisture, and soil organic carbon content were the main factors controlling CH4emissions from these coastal ***, we found that CH4fluxes from the salt marshes in China decreased with latitude, which implied a possible increase in marsh CH4emission in response to global warming that should be considered carefully when developing nature-based climate solutions to achieve national goals for carbon neutrality.

关键词： Salt marsh Mangrove Methane flux Spatial pattern Driving factors China

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A Review of Wideband Circularly Polarized Dielectric Resonator Antennas

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China Communications 2017年第6期14卷 65-79页

作者： ubaid Ullah Mohd fadzil Ain Zainal Arifin Ahmad School of Electrical and Electronic Engineering Universiti Sains Malaysia Nibong Tebal 14300 Pulau Pinang Malaysia School of Material and Mineral Resource Engineering Universiti Sains Malaysia Nibong Tebal 14300 Pulau Pinang Malaysia

This article presents a technical review of circularly polarized(CP) dielectric resonator antennas(DRA) for wideband *** primary objective of this review is,to highlight the techniques used by different researchers for generating circular polarization in ***,a general idea of circular polarization and it advantages over linear polarization is presented,and then all the major developments made in the CP DRA are *** emphasis of the paper is on the wideband circularly polarized dielectric resonator *** current state of the art and all the realizable features of the CP DRA are addressed ***,some recommendations for future CP DRAs are given and the paper ends with concluding remarks.

关键词： circularly polarized dielectric resonator antenna dielectric resonator antenna circular polarization techniques

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Energy Meteorology for the Evaluation of Solar farm Thermal Impacts on Desert Habitats

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Advances in Atmospheric Sciences 2025年第02期 313-326页

作者： Carlos f.M.COIMBRA Department of Mechanical and Aerospace Engineering Jacobs School of Engineering Center of Excellence in Renewable Resource Integration and Center for Energy Research University of California San Diego

This work addresses challenges and opportunities in the evaluation of solar power plant impacts, with a particular focus on thermal effects of solar plants on the environment and vice-versa. Large-scale solar power plants are often sited in arid or desert habitats, which tend to include fauna and flora that are highly sensitive to changes in temperature and humidity. Our understanding of both shortwave(solar) and longwave(terrestrial) radiation processes in solar power plants is complete enough to render the modeling of radiation fluxes with high confidence for most applications. In contrast to radiation, the convective environment in large-scale solar power plants is much more difficult to characterize. Wind direction, wind speed, turbulence intensity, dust concentration, ground condition, panel configuration density, orientation and distribution throughout the solar field, all affect the local environment, the balance between radiation and convection,and in turn, the performance and thermal impact of solar power plants. Because the temperatures of the two sides of photovoltaic(PV) panels depend on detailed convection–radiation balances, the uncertainty associated with convection affects the heat and mass transfer balances as well. Those balances are critically important in estimating the thermal impact of large-scale solar farms on local habitats. Here we discuss outstanding issues related with these transfer processes for utility-scale solar generation and highlight potential pathways to gain useful knowledge about the convective environment directly from solar farms under operating conditions.

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Multifunctional characteristics of 3D printed polymer nanocomposites under monotonic and cyclic compression

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Defence Technology（防务技术） 2023年第12期30卷 13-22页

作者： Pawan Verma Jabir ubaid fahad Alam Suleyman Deveci S.Kumar Department of Mechanical Engineering Khalifa University of Science and TechnologyMasdar InstituteMasdar CityP.O.Box 54224Abu DhabiUnited Arab Emirates Borouge Pte.Ltd. Innovation CentreSas Al Nakhl6951Abu DhabiUnited Arab Emirates James Watt School of Engineering University of GlasgowGlasgowG128QQUK

This study presents the multifunctional characteristics of multi-walled carbon nanotube(MWCNT)/polypropylene random copolymer(PPR) composites enabled via fused filament fabrication(fff) under monotonic and quasi-static cyclic compression. Utilizing in-house MWCNT-engineered PPR filament feedstocks, both bulk and cellular composites were realized. The morphological features of nanocomposites were examined via scanning electron microscopy, which reveals that MWCNTs are uniformly dispersed. The uniformly dispersed MWCNTs forms an electrically conductive network within the PPR matrix, and the resulting nanocomposite shows good electrical conductivity(~10^(-1)S/cm), improved mechanical performance(modulus increases by 125% and compressive strength increases by 25% for 8 wt% MWCNT loading) and pronounced piezoresistive response(gauge factor of 27.9-8.5 for bulk samples)under compression. The influence of strain rate on the piezoresistive response of bulk samples(4 wt% of MWCNT) under compression was also measured. Under repeated cyclic compression(2% constant strain amplitude), the nanocomposite exhibited stable piezoresistive performance up to 100 cycles. The piezoresistive response under repeated cyclic loading with increasing strain amplitude of was also *** gauge factor of BCC and fCC cellular composites(4 wt% of MWCNT) with a relative density of 30%was observed to be 46.4 and 30.2 respectively, under compression. The higher sensitivity of the BCC plate-lattice could be attributed to its higher degree of stretching-dominated deformation behavior than the fCC plate-lattice, which exhibits bending-dominated behavior. The 3D printed cellular PPR/MWCNT composites structures were found to show excellent piezoresistive self-sensing characteristics and open new avenues for in situ structural health monitoring in various applications.

关键词： Carbon nanotubes Nanoengineered polymer composites 3D printing Piezoresistive self-sensing Lattice structures

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Non-integer Order Control Scheme for Pressurized Water Reactor Core Power

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Computers, Materials & Continua 2022年第7期72卷 651-662页

作者： Ibrahim M.Mehedi Maher H.AL-Sereihy Asmaa ubaid Al-Saggaf.ubaid M.Al-Saggaf Department of Electrical and Computer Engineering(ECE) King Abdulaziz UniversityJeddah21589Saudi Arabia Center of Excellence in Intelligent Engineering Systems(CEIES) King Abdulaziz UniversityJeddah21589Saudi Arabia

Tracking load changes in a pressurized water reactor(PWR)with the help of an efficient core power control scheme in a nuclear power station is very *** reason is that it is challenging to maintain a stable core power according to the reference value within an acceptable tolerance for the safety of *** overcome the uncertainties,a non-integer-based fractional order control method is demonstrated to control the core power of *** available dynamic model of the reactor core is used in this *** power is controlled using a modified state feedback approach with a non-integer integral scheme through two different approximations,CRONE(Commande Robuste d’Ordre Non Entier,meaning Non-integer orderRobust Control)and fOMCON(non-integer order modeling and control).Simulation results are produced using MATLAB■*** non-integer results are compared with an integer order PI(Proportional Integral)algorithm to justify the effectiveness of the proposed ***-spacemodel Core power control Non-integer control Pressurized water reactor PI controller CRONE fOMCON.

关键词： Sate-space model core power control non-integer control pressurized water reactor PI controller CRONE fOMCON

Smart Techniques for LULC Micro Class Classification Using Landsat8 Imagery

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Computers, Materials & Continua 2023年第3期74卷 5545-5557页

作者： Mutiullah Jamil Hafeez ul Rehman SaleemUllah Imran Ashraf Saqib ubaid Department of Computer Science Khwaja Fareed University of Engineering and Information TechnologyRahim Yar Khan64200Pakistan Department of Information and Communication Engineering Yeungnam UniversityGyeongsan-si38541Korea

Wheat species play important role in the price of products and wheat production *** are several mathematical models used for the estimation of the wheat crop but these models are implemented without considering the wheat species which is an important independent *** task of wheat species identification is challenging both for human experts as well as for computer vision-based *** the use of satellite remote sensing,it is possible to identify and monitor wheat species on a large scale at any stage of the crop life *** this work,nine popular wheat species are identified by using Landsat8 operational land imager(OLI)and thermal infrared sensor(TIRS)*** thousand samples of eachwheat crop species are acquired every fifteen days with a temporal resolution of ten multispectral bands(band two to band eleven).This study employs random forest(Rf),artificial neural network,support vector machine,Naive Bayes,and logistic regression for nine types of wheat *** addition,deep neural networks are also *** results indicate that Rf shows the best performance of 91%accuracy while DNN obtains a 90.2%*** suggest that remotely sensed data can be used in wheat type estimation and to improve the performance of the mathematical models.

关键词： Mathematical model wheat crop estimation landsat8 remote sensing machine learning random forest deep neural network

CHfS: Complex hesitant fuzzy sets‐their applications to decision making with different and innovative distance measures

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CAAI Transactions on Intelligence Technology 2021年第1期6卷 93-122页

作者： Harish Garg Tahir Mahmood ubaid ur Rehman Zeeshan Ali School of Mathematics Thapar Institute of Engineering and TechnologyDeemed UniversityPatialaPunjabIndia Department of Mathematics and Statistics International Islamic UniversityIslamabadPakistan

The objective of the authors is to establish an innovative concept of the complex hesitant fuzzy set(CHfS),which is the combination of the hesitant fuzzy set and the complex fuzzy set to manage complex and awkward information in the real‐decision *** structure and the basic properties of the proposed set are studied in *** on the internal structure of the set and to find the degree of the discrimination between the pairs of the CHfSs,the generalized distance measures and modified generalized distance measures are *** properties and their relationship between them are derived in ***,several cases of the proposed measures are exposed which reduce them to the existing ***,based on these proposed measures,a decision‐making approach is established under the uncertain environment and several numerical examples are given to examine the feasibility and validity of the explored ***,the credibility of the modified and parameterized distance measures based on CHfSs is verified by comparing them with some existing measures.

关键词： theory. verified validity