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Time-dependent lateral response of pile embedded in elasto-plastic soil

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Journal of Central South University 2010年第2期17卷 372-380页

作者： J.m.abbas Z.H.CHIK m.R.TAHA Q.S.m.SHAFIQU Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia Department of Civil Engineering Nahrain University

A two-dimensional （2D） finite element analysis was carried out to assess the time-dependent behavior of single vertical pile embedded in elasto-plastic soil. The finite element analyses were carried out using the linear elastic model for the structure of the pile, while the mohr-Coulomb model was used for representing the soil behavior surrounding the pile. The study includes cohesionless and cohesive soil to assess the lateral response of pile in the two types of soil. The whole geoteehnical model is suitable for problem of piles to determine the design quantities such as lateral deformation, lateral soil stress and its variation with time. The model is verified based on the results of published cases and there is good comparison between the results of published ease and the present simulation model. It is found that, the pile in cohesionless soil has more resistance in the rapid loading and less one in the long term loading. On the other hand, the pile in cohesive soil shows opposite behavior.

关键词： single pile consolidation effect lateral response soil pressure 2D finite element method

Structural, electronic, and optical properties of ZnO_(1-x)Se_x alloys using first-principles calculations

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Chinese Physics B 2013年第8期22卷 581-588页

作者： muhammad Rashid Fayyaz Hussain muhammad Imran S A Ahmad N A Noor m U Sohaib S m Alay-e-abbas Department of Physics Simulation Laboratory the Islamia University of Bahawalpur63100 Pakistan Department of Physics University of the Punjab Quaid-e-Azam Campus54590 Lahore Pakistan Lahore Development Authority 54590 Lahore Pakistan Department of Physics GC University FaisalabadAllama Iqbal Road Faisalabad 38000 Pakistan

The structural, electronic, and optical properties of binary ZnO, ZnSe compounds, and their ternary ZnOl_xSex alloys are computed using the accurate full potential linearized augmented plane wave plus local orbital （FP-LAPW ＋ lo） method in the rocksalt （B 1） and zincblende （B3） crystallographic phases. The electronic band structures, fundamental energy band gaps, and densities of states for ZnO1_xSex are evaluated in the range 0 〈 x 〈 1 using Wu-Cohen （WC） generalized gradient approximation （GGA） for the exchange-correlation potential. Our calculated results of lattice parameters and bulk modulus reveal a nonlinear variation for pseudo-binary and their ternary alloys in both phases and show a considerable deviation from Vegard＇s law. It is observed that the predicted lattice parameter and bulk modulus are in good agreement with the available experimental and theoretical data. We establish that the composition dependence of band gap is semi-metallic in B1 phase, while a direct band gap is observed in B3 phase. The calculated density of states is described by taking into account the contribution of Zn 3d, O 2p, and Se 4s, and the optical properties are studied in terms of dielectric functions, refractive index, reflectivity, and energy loss function for the B3 phase and are compared with the available experimental data.

关键词： density functional theory alloys structural electronic optical properties

Few-Shot Learning for Discovering Anomalous Behaviors in Edge Networks

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Computers, materials & Continua 2021年第11期69卷 1823-1837页

作者： merna Gamal Hala m.abbas Nour moustafa Elena Sitnikova Rowayda A.Sadek Department of Information Technology Helwan UniversityCairoEgypt Department of Computer Science Helwan UniversityCairoEgypt School of Engineering and Information Technology University of New South Wales at ADFACanberraAustralia

Intrusion Detection Systems(IDSs)have a great interest these days to discover complex attack events and protect the critical infrastructures of the Internet of Things(IoT)*** IDSs based on shallow and deep network architectures demand high computational resources and high volumes of data to establish an adaptive detection engine that discovers new families of attacks from the edge of IoT ***,attackers exploit network gateways at the edge using new attacking scenarios(i.e.,zero-day attacks),such as ransomware and Distributed Denial of Service(DDoS)*** paper proposes new IDS based on Few-Shot Deep Learning,named CNN-IDS,which can automatically identify zero-day attacks from the edge of a network and protect its IoT *** proposed system comprises two-methodological stages:1)a filtered Information Gain method is to select the most useful features from network data,and 2)one-dimensional Convolutional Neural Network(CNN)algorithm is to recognize new attack types from a network’s *** proposed model is trained and validated using two datasets of the UNSW-NB15 and *** experimental results showed that it enhances about a 3%detection rate and around a 3%–4%falsepositive rate with the UNSW-NB15 dataset and about an 8%detection rate using the BoT-IoT dataset.

关键词： Convolution neural network information gain few-shot learning IoT edge computing

Novel synthesis of stabilized Bi_(1-x-y)Gd_(x)Dy_(y)O_(1.5) solid electrolytes with enhanced conductivity for intermediate temperature solid oxide fuel cells(SOFCs)

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Journal of Rare Earths 2024年第10期42卷 1903-1911页

作者： Ahmed H.Ibrahim Yehia m.abbas H.A.Ayoub marwa H.Ali mustafa Aldoori materials Science Laboratory Physics DepartmentFaculty of ScienceSuez Canal University41522IsmailiaEgypt ministry of Higher Education and Scientific Research Aliraqia University10011BaghdadIraq

Herein,we report the synthesis of a Dy-Gd co-doped cubic phase-stabilized Bi_(2)O_(3) solid electrolyte system via solid-state processing under atmospheric *** with Dy^(3+) and Gd^(3+) has been observed to significantly enhance the densification process during sintering for stabilization purposes,thereby improving the electrical properties of δ-Bi_(2)O_(3)-type *** synthesized ceramics were characterized using X-ray diffraction(XRD),field emission scanning electron microscopy-energy dispersive X-ray spectroscopy(FESEm-EDX),thermal gravimetry/differential thermal analysis(TG/DTA),and the four-point probe technique(4PPT).XRD analysis reveals that the samples Bi_(1-x-y)Gd_(x)Dy_(y)O_(1.5)(y=0.05/x=0.05,0.10,0,15,and 0.20,and x=0.05/y=0.10,0.15,and 0.20) exhibit a stable face-centered cubic δ-phase and a mixed-phase crystallographic *** XRD analysis of the stabilized δ-phase suggests that the prepared oxides show a face-centered cubic(FCC) structure with a space group of *** micrographs reveal that the composition Bi_(0.90)Gd_(0.05)Dy_(0.05)O_(1.5) has no significant ***,an evident increase in the pore formation is observed as the amount of Gd_(2)O_(3) increases until it reaches 20%.This finding suggests that dense pellets are formed during the sintering process at 900-1000℃.The DTA analyses were performed to verify the phase stability,which agrees with the XRD *** electrochemical performance of the synthesized Dy-Gd co-doped Bi_(2)O_(3)solid electrolyte system was evaluated and analyzed in detail by using the electrochemical impedance spectroscopy(EIS) technique,Based on EIS and conductivity measurements,Bi_(0.75)Gd_(0.20)Dy_(0.05)O_(1.5) exhibits the lowest activation energy of 0.519 eV and the highest conductivity value of 0.398 S/cm at 627℃compared to the other samples;this composition can be used as a solid electrolyte for intermediatetemperature solid oxide fuel cells(SOFCs).

关键词： Solid oxide fuel cells(SOFCs) Rare earths Solid-state processing Rietveld Fast Fourier transform(FFT) Electrochemical impedance spectroscopy(EIS)

Oxidative degradation of sunflower oil blended with roasted sesame oil during heating at frying temperature

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Grain & Oil Science and Technology 2023年第1期6卷 34-42页

作者： m.Al Amin m.abbas Ali m.Shamsul Alam Aktarun Nahar Sook Chin Chew Department of Chemistry Rajshahi University of Engineering&TechnologyRajshahi 6204Bangladesh Xiamen University Malaysia CampusBandar SereniaSepang 43900SelangorMalaysia

The efficacy of roasted sesame oil(SO)on the oxidation deterioration of sunflower oil(SFO)during heating was *** concentrations of SO in the SFO were 0,10%,20%,and 30%by *** oxidation profile of oil samples was monitored by evaluating the generation of oxidation products and chemical alterations in the oils'composition during heating at frying temperature(180℃).The results showed that the oxidation parameters(free fatty acid,peroxide value,p-anisidine value,total oxidation status,thiobarbituric acid value,and color index)increased significantly in SFO compared to blends or SO during thermal *** heating,the concentration of polyunsaturated fatty acids(PUFA)was reduced with increased level of saturated fatty acids;these results were observed more in SFO than those of SO or blend ***,the presence of SO in SFO reduced the decomposition of *** Fourier-transform infrared spectroscopy,the peak intensities were significantly altered in SFO compared to the blend oils during *** on the most analytical data,it may be agreed that the heating at frying temperature led to the generation of relatively higher contents of oxidative products in SFO compared to blend oils,showing a lower degree of oxidation occurred in *** best frying performance for the SFO was achieved by using 30%SO extracted from the roasted sesame *** study showed the proper blending of high polyunsaturated oil with SO can produce oil blends with high nutritional values and enhanced stability for daily cooking and deep-frying applications.

关键词： Sesame oil Sunflower oil Fatty acids Oxidative stability Blend oil

DEPICT:A High-level Formal Language for modeling Constraint Satisfaction Problems

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International Journal of Automation and computing 2008年第2期5卷 208-216页

作者： Abdulwahed m.abbas Edward P.K.Tsang Ahmad H.Nasri Department of Computer Science The University of Balamand Department of Computing and Electronic SystemsThe University of EssexDepartment of Computer ScienceThe American University of BeirutP.O.Box 100TripoliLebanonWivenhoe ParkColchester CO4 3SQUKP.O.Box:11-0236Riad EI-SolhBeirutLebanon

The past decade witnessed rapid development of constraint satisfaction technologies, where algorithms are now able to cope with larger and harder problems. However, owing to the fact that constraints are inherently declarative, attention is quickly turning toward developing high-level programming languages within which such problems can be modeled and also solved. Along these lines, this paper presents DEPICT, the language. Its use is illustrated through modeling a number of benchmark examples. The paper continues with a description of a prototype system within which such models may be interpreted. The paper concludes with a description of a sample run of this interpreter showing how a problem modeled as such is typically solved.

关键词： Constraint satisfaction problems (CSPs) and languages formal specifications typed predicate calculus language interpreter

Tailoring the optical and magnetic properties of La-Bam hexaferrites by Ni substitution

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Chinese Physics B 2022年第2期31卷 570-575页

作者： Hafiz T.Ali mRamzan m Imran Arshad Nicola A.morley m.Hassan abbas mohammad Yusuf Atta Ur Rehman Khalid mahmood Adnan Ali Nasir Amin mAjaz-un-Nabi Department of mechanical Engineering College of EngineeringTaif UniversityTaif 21944Saudi Arabia Department of Physics Government College UniversityFaisalabadPakistan Department of materials Science and Engineering University of SheffieldSir Robert Hadfield BuildingMapping St.SheffieldS13JDUK Department of Clinical Pharmacy College of PharmacyTaif UniversityTaif 21944Saudi Arabia

We investigate the impact of Ni insertion on the structural,optical,and magnetic properties of Ba_(0.8)La_(0.2)Fe_(12-x)Ni_(x)O_(19)hexaferrites(Ni substituted La-Bam hexaferrites).Samples were prepared using the conventional co-precipitation method and sintered at 1000℃for 4 hours to assist the crystallization *** analysis of the structure of the samples was carried out using an x-ray diffraction(XRD)*** m-type hexagonal structure of all the samples was confirmed using XRD *** lattice parameters a and c were found to be in the ranges of 5.8925±0.001 nm–5.8952±0.001 nm and 23.2123±0.001 nm–23.2219±0.001 nm,*** m-type hexagonal nature of the prepared samples was also indicated by the presence of corresponding FT-IR bands and Raman modes in the FT-IR and Raman spectra,*** results confirmed the successful synthesis of the samples according to the required stoichiometric ratio.A UV-vis spectrometer was used to record the absorption spectra of the prepared samples in the wavelength range of 200 nm–1100 *** optical energy bandgap of the samples was found to be in the range of 1.21 eV–3.39 *** m–H loops of the samples were measured at room temperature at an applied magnetic field range of 0 kOe–60 kOe.A high saturation magnetization of 99.92 emu/g was recorded in the sample with x=0 at a microwave operating frequency of 22.2 *** high value of saturation magnetization is due to the substitution of La3+ions at the spin-up(12k,2a,and 2b)*** Ni substitution is proven to be a potential candidate for the tuning of the optical and magnetic parameters of m-type ***,we suggest that the prepared samples are suitable for use in magneto-optic applications.

关键词： m-type hexaferrite nanostructured materials magnetic properties optical properties

Bipolar tri-state resistive switching characteristics in Ti/CeO_x/Pt memory device

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Chinese Physics B 2014年第12期23卷 333-338页

作者： m.Ismail m.W.abbas A.m.Rana I.Talib E.Ahmed m.Y.Nadeem T.L.Tsai U.Chand N.A.Shah m.Hussain A.Aziz m.T.Bhatti Department of Physics Bahauddin Zakariya University Department of Electronics Engineering and Institute of Electronics National Chiao Tung University Thin Films Technology Research Laboratory Department of Physics COMSATS Institute of Information Technology Center for High Energy Physics University of Punjab

Highly repeatable multilevel bipolar resistive switching in Ti/Ce Ox/Pt nonvolatile memory device has been demonstrated. X-ray diffraction studies of Ce O2 films reveal the formation of weak polycrystalline structure. The observed good memory performance, including stable cycling endurance and long data retention times（〉10^4s） with an acceptable resistance ratio（～10^2）, enables the device for its applications in future non-volatile resistive random access memories（RRAms）. Based on the unique distribution characteristics of oxygen vacancies in Ce Ox films, the possible mechanism of multilevel resistive switching in Ce Ox RRAm devices has been discussed. The conduction mechanism in low resistance state is found to be Ohmic due to conductive filamentary paths, while that in the high resistance state was identified as Ohmic for low applied voltages and a space-charge-limited conduction dominated by Schottky emission at high applied voltages.

关键词： multilevel resistive switching Schottky emission cerium oxide oxygen vacancy

Preparation and Properties of Some Chemical and Electrochemical γ-mnO_2

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Journal of materials Science & Technology 2001年第3期17卷 351-354页

作者： H.m.abbas, Kh. S.Abou-El-Sherbini, m.H.Askar and A. m. Hashim Dept.of Physical Centre, National Research Centre, Tahiu, Dokki, Cairo, Egypt E-mail: sherbini@*** Natl Res Ctr Dept Phys Ctr Cairo Egypt

Chemically prepared electrolytic 2-mn02 and an electrodeposited mnO2 doped with Ce(Ⅲ) were subjected to physicochemical studies. X-ray diffractometry, density measurements, chem-ical analysis and thermal analysis were used to determine the structure and chemical disorder present. The samples prepared chemically (CmD) or electrochemically (EmD) showed a variable amount of de Wolff disorder (Pr) and microtwinning (Tw). manganese dioxide prepared in the presence of Ce(Ⅲ) showed appreciable decrease in de Wolff defect and a large amount of microtwinning. Thermal analysis showed a loss of weight due to the physically adsorbed and the structural (OH) water, from which the activation energy was calculated. Chemical composition and formulae calculated on the bases of cation vacancy model, cleared that Ce(lIl)-doped sample has a remarkable increase in the vacancies population associated with higher structural water content. This leads to lower activation energy of water release, and consequently it is supposed to acquire higher electrochemical activity.

关键词： EmD mnO2