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A Multifunctional Chiral Metasurface with Asymmetric Transmission and Linear-Polarization Conversion

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Transactions of Nanjing University of Aeronautics and Astronautics 2024年第S1期41卷 21-26页

作者： AFZAL ahmed CAO Qunsheng MUHAMMAD sajjad College of Electronics and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China

In this paper,a multifunctional chiral metasurface is presented to achieve asymmetric transmission(AT)and linear-polarization conversion(LPC).The designed metasurface consists of a cross swords-like shape and two holes in the lower side of the unit *** the frequency band from 8.3 GHz to 10.4 GHz,AT is realized with more than 90%efficiency and the same chiral metasurface transforms linear polarized wave into its orthogonal counterpart with high *** LPC,the polarization conversion ratio(PCR)is greater than 95%.The proposed metasurface is stable against the incident angles of striking electromagnetic(EM)waves up to 60°for both operations of AT and LPC.

关键词： chiral metasurface polarization conversion asymmetric tranmission plasmon resonances

Analysis of cerium substitution in Co-Sr based spinel ferrites for high frequency application

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Journal of Rare Earths 2024年第9期42卷 1755-1763,I0005页

作者： Laura Khudaysh Inas A.ahmed Syeda Rabia Ejaz sajjad Ahmad Khan Yasir A.Haleem Mohamed M.Ibrahim Mahmood Ali Hafiz Muhammad Tahir Farid Zeinhom M.El-Bahy Department of Physics Faculty of ScienceJazan UniversityJazan45142Saudi Arabia Department of Chemistry Faculty of ScienceKing Khalid UniversityAbha62224Saudi Arabia Department of Physics The Government Sadiq College Women UniversityBahawalpur63100Pakistan Institute of Physics Khwaja Fareed University of Engineering and Information TechnologyRahim Yar Khan64200Pakistan Department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Centre of Excellence in Solid State Physics University of the PunjabLahorePakistan Department of Physics Government CollegeTaunsa Sharif32200Pakistan Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City11884CairoEgypt

Spinel ferrites exhibit exceptional magnetic properties,making them a distinctive class of magnetic *** sol-gel technique was utilized for the synthesis of spinel ferrites with the chemical formula Co_(0.6)Sr_(0.4)Ce_(x)Fe_(2-x)O_(4). Following that,a comprehensive X-ray diffraction analysis unveiled the crystalline cubic structure of the synthesized *** the utilization of the M-H loop approach,the ferromagnetic attributes of ferrites were assessed,and the assimilation of rare earth elements led to substantial enhancements in saturation magnetization,remanence,and *** ferrites with a high concentration of rare earth elements have improved direct current resistivity and activation *** logarithm of a material's resistance increased from 5.29 to 8.12 Ω·cm as cerium is *** a change in the amount of cerium,the activation energy goes up from 0.19 to *** changing the frequency from 5.5 to 9.5 GHz,the dielectric characteristics were *** the frequency goes up,the dielectric constant goes *** ferrites that have been made better in every way can be used in high-frequency applications.

关键词： Activation energy DC electrical resistance Remanence magnetization Cobalt strontium spinel ferrites High frequency application Rare earths

Strong interfacial charge transfer between hausmannite manganese oxide and alumina for efficient photocatalysis

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Chinese Journal of Chemical Engineering 2021年第5期34卷 147-159页

作者： Aisha Kanwal Shamaila sajjad sajjad ahmed Khan Leghari Muhammad Naeem Khan International Islamic University H-10 IslamabadPakistan Pakistan Institute of Engineering and Applied Sciences Islamabad 44000Pakistan Department of Chemistry Government College of ScienceLahorePakistan

Well crystalline manganese oxide(Mn_(3)O_(4))nanoparticles anchored on gamma alumina(γ-Al_(2)O_(3))have been successfully tailored via a proficient and cost effective chemical process as an efficient material for photo *** indicated the composite formation ofγ-Al_(2)O_(3) and hausmannite structure of Mn_(3)O_(4).SEM and TEM revealed that hetero structure of Mn_(3)O_(4)/γ-Al_(2)O_(3) exhibits an amalgam of aggregated nanoparticles and *** demonstrated the chemical states of binary *** band gap tuning has been performed withγ-Al_(2)O_(3) nanoparticles by assimilating hausmannite Mn_(3)O_(4) particles into flower like microstructure of Al_(2)O_(3).The photoluminescence spectra affirmed the enhancement in charge separation in Mn_(3)O_(4)/γ-Al_(2)O_(3) binary hybrid *** band gap becomes narrow with the increase in concentrations of Mn_(3)O_(4).The narrowing of band gap is concorded with crystalline domains of primary aggregated *** elucidate the mechanism of the photocatalytic activity linear sweep voltammetry was *** results showed that Mn_(3)O_(4)/γ-Al_(2)O_(3) nanocomposite revealed the enhancement in current density as compared to pureγ-Al_(2)O_(3) which confirmed the electron transfer from Mn_(3)O_(4) toγ-Al_(2)O_(3) through the interfacial potential gradient in conduction *** optimum concentration of 6.0%Mn_(3)O_(4)/γ-Al_(2)O_(3) for hybrid structure showed an excellent photocatalytic activity under visible light due to narrow band gap *** degree distribution of Mn_(3)O_(4) nano architects overlying onγ-Al_(2)O_(3) induces a significant synergic effect betweenγ-Al_(2)O_(3) and hausmannite phase of manganese oxide(Mn_(3)O_(4)).This strong interfacial contact betweenγ-Al_(2)O_(3) and Mn_(3)O_(4) endures the quick transfer of photo generated charge carriers across interface.

关键词： Hausmannite Mn_(3)O_(4) Alumina Band gap tuning Interfacial charge transfer Nanomaterials Catalysis

Competitive role of nitrogen functionalities of N doped GO and sensitizing effect of Bi_(2)O_(3)QDs on TiO_(2)for water remediation

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Journal of Environmental Sciences 2021年第10期33卷 107-119页

作者： Saima Noor Shamaila sajjad sajjad ahmed Khan Leghari Cristina Flox Saeed Ahmad International Islamic University Islamabad 44000Pakistan Department of Chemistry and Materials Science Aalto UniversityEspoo 16100Fl-00076Finland Pakistan Institute of Engineering and Applied Sciences Islamabad 44000Pakistan Department of Applied Physics Aalto UniversityEspoo 15100Fl-00076Finland

The promising solar irradiated photocatalyst by pairing of bismuth oxide quantum dots(BQDs)doped TiO_(2)with nitrogen doped graphene oxide(NGO)nanocomposite(NGO/BQDs-TiO_(2))was *** was used for degradation of organic pollutants like 2,4-dichlorophenol(2,4-DCP)and stable dyes,*** B and Congo Red.X-ray diffraction(XRD)profile of NGO showed reduction in oxygenic functional groups and restoring of graphitic crystal *** characteristic diffraction peaks of TiO_(2)and its composites showed crystalline anatase TiO_(2).Morphological images represent spherical shaped TiO_(2)evenly covered with BQDs spread on NGO *** surface linkages of NO-O-Ti,C-O-Ti,Bi-O-Ti and vibrational modes are observed by Fourier transform infrared spectroscopy(FTIR)and Raman *** and NGO modified TiO_(2)results into red shifting in visible region as studied in diffused reflectance spectroscopy(DRS).NGO and BQDs in TiO_(2)are linked with defect centers which reduced the recombination of free charge carriers by quenching of photoluminescence(PL)intensities.X-ray photoelectron spectroscopy(XPS)shows that no peak related to C-O in NGO/BQDs-TiO_(2)is *** indicated that doping of nitrogen into GO has reduced some oxygen functional *** functionalities in NGO and photosensitizing effect of BQDs in ternary composite have improved photocatalytic activity against organic *** byproducts during photo degradation process of 2,4-DCP were studied through high performance liquid chromatography(HPLC).Study of radical scavengers indicated that O_(2)^(·-) has significant role for degradation of 2,*** investigations propose that fabricated nanohybrid architecture has potential for degradation of environmental pollutions.

关键词： Bi_(2)O_(3)quantum dots Nitrogen doped graphene oxide Nitrogen defects TiO_(2) 2,4-Dichlorophenol Water treatment

SVB1 and SVB2 Regulate ABA Response and Plant Morphology in Arabidopsis Thaliana

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SVB1 and SVB2 Regulate ABA Response and Plant Morphology in ...

作者： sajjad ahmed 东北师范大学

学位级别：硕士

脱落酸(Abscisic acid,ABA)是调控植物生长发育及植物对外界环境响应的重要胁迫激素。在拟南芥中越来越多基因已被报道参与调控ABA信号转导和胁迫应答,但还有很多ABA响应基因的功能尚未得到研究。在本文中,我们发现拟南芥At4g24130(SVB1... 详细信息

脱落酸(Abscisic acid,ABA)是调控植物生长发育及植物对外界环境响应的重要胁迫激素。在拟南芥中越来越多基因已被报道参与调控ABA信号转导和胁迫应答,但还有很多ABA响应基因的功能尚未得到研究。在本文中,我们发现拟南芥At4g24130(SVB1)和At1g56580(SVB2)是ABA响应基因。定量RT-PCR结果显示ABA处理后SVB1和SVB2的表达量显著增加。原生质体转染实验表明SVB1和SVB2定位在除了核以外的整个细胞中。RT-PCR结果表明SVB1和SVB2两个基因在成熟的花中表达量都很高,但是SVB2也在莲座叶、荚果和茎等其他组织器官中表达。种子萌发实验表明SVB2过表达植株以及svb1单突变体和svb1 svb2双突变体对ABA敏感性增加。但svb2单突变体种子较野生型萌发早,且对ABA敏感性降低。绿苗率实验结果表明35S:SVB2转基因植株和svb1 svb2双突变体对ABA敏感性增加。盐处理实验表明SVBs在调控植物的盐胁迫响应中具有冗余功能。表型观察发现SVB2过表达植株和野生型相比种子更大,根长也更长。显微观察发现svb2单突变体表皮毛数量减少,并且只有1和2个分支的表皮毛的数量明显增多。综上所述,我们的研究结果表明SVBs参与调控拟南芥形态发育及其对ABA的响应。

关键词：脱落酸拟南芥绿苗率 SVB1 SVB2 表皮毛

Use of Scrapped Rubber Tires for Sustainable Construction of Manhole Covers

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Journal of Renewable Materials 2021年第5期9卷 1013-1029页

作者： Sadaqat Ullah Khan Afzal ahmed sajjad Ali Ayesha Ayub ahmed Shuja Muhammad Ahsan Shahid Department of Urban and Infrastructure Engineering NED University of Engineering and TechnologyKarachi75270Pakistan Department of Civil Engineering NED University of Engineering and TechnologyKarachi75270Pakistan

Scrapped tires from vehicles are produced in large quantities. Despite numerous existing uses of scrapped tires, alarge quantity ends up at the landfill sites, which contributes to environmental degradation. The development ofmore applications of scrapped tire usage can reduce the disposal of tires at landfill sites. This research proposes anovel use of scrapped tires by using the strips taken from scrapped tires in replacement of steel bars as reinforcement. Manhole covers were produced using scrapped tires by completely replacing the steel with scrapped *** different samples of manhole covers were prepared and tested. The highest bearing capacity of 25.5 kN wasrecorded with a sample of 100 mm thickness made with cementitious composite, which is 2.25 times higher thanthe bearing capacity of a conventional reinforced-concrete manhole cover. The use of manhole covers made withscrapped tires can effectively address the theft issue of manhole covers. The lifecycle cost analysis shows that themanhole cover made with scrapped tires is 3.4 times more cost-effective in comparison with the conventionalmanhole cover. This research shows a new avenue of the potential use of scrapped tires as reinforcement in structures, which can improve sustainable construction practices.

关键词： Scrapped tires sustainability manhole cover waste management recycling

Reconfigurable Sensing Time in Cooperative Cognitive Network Using Machine Learning

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Computers, Materials & Continua 2023年第3期74卷 5209-5227页

作者： Noor Gul Saeed ahmed Su Min Kim Muhammad sajjad Khan Junsu Kim Department of Electronics Engineering Korea Polytechnic UniversityGyeonggi-do15073Korea Department of Electronics University of PeshawarPeshawar25120Pakistan Deparment of Electrical Engineering Mirpur University of Science of TechnologyAJ&KMirpur10250Pakistan Department of Electrical Engineering International Islamic UniversityIslamabad44000Pakistan

A cognitive radio network(CRN)intelligently utilizes the available spectral resources by sensing and learning from the radio environment to maximize spectrum *** CRNs,the secondary users(SUs)opportunistically access the primary users(PUs)***,unambiguous detection of the PU channel occupancy is the most critical aspect of the operations of *** spectrum sensing(CSS)is rated as the best choice for making reliable sensing *** paper employs machinelearning tools to sense the PU channels reliably in *** sensing parameters are reconfigured to maximize the spectrum utilization while reducing sensing error and cost with improved channel *** fine-k-nearest neighbor algorithm(FKNN),employed in this paper,estimates the number of samples based on the nature of the channel under-specific detection and false alarm probability *** simulation results reveal that the sensing cost is suppressed by reducing the sensing time and exploiting the traditional fusion rules,validating the effectiveness of the proposed ***,the global decision made at the fusion center(FC)based on the modified sensing samples,results low energy consumption,higher throughput,and improved detection with low error probabilities.

关键词： Energy detection machine learning k-nearest-neighbor decision tree linear regression throughput energy consumption

Analysing the relationship between drought and soil erosion using vegetation health index and RUSLE models in Godavari middle sub-basin,India

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Geoscience Frontiers 2022年第2期13卷 21-33页

作者： Md Masroor Haroon sajjad Sufia Rehman Roshani Singh Md Hibjur Rahaman Mehebub Sahana Raihan ahmed Ram Avtar Department of Geography Faculty of Natural SciencesJamia Millia IslamiaNew DelhiIndia School of Environment Education and Development(SEED)University of ManchesterUnited Kingdom Graduate School of Environment Earth Science Hokkaido UniversityJapan

Drought is a natural phenomenon posing severe implications for soil,groundwater and agricultural *** has been recognized as one of the most pervasive global change drivers to affect the *** being a weakly renewable resource takes a long time to form,but it takes no time to ***,the response of soil to drought conditions as soil loss is not manifested in the existing ***,this study makes a concerted effort to analyze the relationship between drought conditions and soil erosion in the middle sub-basin of the Godavari River in *** remote sensing data was utilized for driving drought indices during ***,we constricted Temperature condition index(TCI)and Vegetation Condition Index(VCI)from Land Surface Temperature(LST)and Enhanced Vegetation Index(EVI)derived from MODIS *** and VCI were then integrated to determine the Vegetation Health Index(VHI).Revised Universal Soil Loss Equation(RUSLE)was utilized for estimating soil *** relationship between drought condition and vegetation was ascertained using the Pearson *** of the northern and southern watersheds experienced severe drought condition in the sub-basin *** mean frequency of the drought occurrence was 7.95 *** average soil erosion in the sub-basin was estimated to be 9.88 t ha^(-1)year^(-1).A positive relationship was observed between drought indices and soil erosion values(r value being 0.35).However,wide variations were observed in the distribution of spatial *** various factors,the slope length and steepness were found to be the main drivers of soil erosion in the ***,the study calls for policy measures to lessen the impact of drought and soil erosion.

关键词： Drought vulnerability Soil erosion RUSLE Vegetation Health Index(VHI) Godavari middle sub-basin

Reinforcing Artificial Neural Networks through Traditional Machine Learning Algorithms for Robust Classification of Cancer

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Computers, Materials & Continua 2023年第5期75卷 4293-4315页

作者： Muhammad Hammad Waseem Malik sajjad ahmed Nadeem Ishtiaq Rasool Khan Seong-O-Shim Wajid Aziz Usman Habib Department of Computer Sciences and Information Technology University of Azad Jammu and KashmirMuzaffarabad13100Pakistan Department of Computer Science and AI College of Computer Science and EngineeringUniversity of JeddahJeddah23890Saudi Arabia Department of Computer and Network Engineering College of Computer Science and EngineeringUniversity of JeddahJeddah23890Saudi Arabia Department of AI&DS School of ComputingNational University of Computer and Emerging SciencesIslamabad44000Pakistan

Machine Learning(ML)-based prediction and classification systems employ data and learning algorithms to forecast target ***,improving predictive accuracy is a crucial step for informed *** the healthcare domain,data are available in the form of genetic profiles and clinical characteristics to build prediction models for complex tasks like cancer detection or *** ML algorithms,Artificial Neural Networks(ANNs)are considered the most suitable framework for many classification *** network weights and the activation functions are the two crucial elements in the learning process of an *** weights affect the prediction ability and the convergence efficiency of the *** traditional settings,ANNs assign random weights to the *** research aims to develop a learning system for reliable cancer prediction by initializing more realistic weights computed using a supervised setting instead of random *** proposed learning system uses hybrid and traditional machine learning techniques such as Support Vector Machine(SVM),Linear Discriminant Analysis(LDA),Random Forest(RF),k-Nearest Neighbour(kNN),and ANN to achieve better accuracy in colon and breast cancer *** system computes the confusion matrix-based metrics for traditional and proposed *** proposed framework attains the highest accuracy of 89.24 percent using the colon cancer dataset and 72.20 percent using the breast cancer dataset,which outperforms the other *** results show that the proposed learning system has higher predictive accuracies than conventional classifiers for each dataset,overcoming previous research ***,the proposed framework is of use to predict and classify cancer patients ***,this will facilitate the effective management of cancer patients.

关键词： ANN decision support systems gene-expression data hybrid classification machine learning predictive analytics