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Effectiveness of Meso-Scale Approach in Modeling of Plain Concrete Beam
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The main aim of this research paper is investigating the effectiveness and validity of Meso-Scale Approach (MSA) as a modern technique for the modeling of plain concrete beams. Simply supported plain concrete beam was subjected to two-point loading to detect the response in flexural. Experimentally, a concrete mix was designed and prepared to produce three similar standard concrete prisms for flexural testing. The coarse aggregate used in this mix was crushed aggregate. Numerical Finite Element Analysis (FEA) was conducted on the same concrete beam using the meso-scale modeling. The numerical model was constructed to be a bi-phasic material consisting of cement mortar and coarse aggregate. The interface between the two consisting materials was assumed fully bonded interface. In the ABAQUS program, the Extended Finite Element Method (XFEM) was employed for the treatment of the discontinuity problems, which is accompanied by cracking during the fracture process of plain concrete. The behavior and response of the beam in both meso-scale numerical analysis and experimental test were found in a good agreement. Another check was added by comparing the results using thin-beam theory assuming the concrete as a homogenous linear-elastic material. The result of this comparison showed that the meso-scale model analysis lies between theoretical and experimental models.

 

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Economics And Administrative Sciences
Comparison Between Maximum Likelihood and Bayesian Methods For Estimating The Gamma Regression With Practical Application
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In this paper, we will illustrate a gamma regression model assuming that the dependent variable (Y) is a gamma distribution and that it's mean ( ) is related through a linear predictor with link function which is identity link function g(μ) = μ. It also contains the shape parameter which is not constant and depends on the linear predictor and with link function which is the log link and we will estimate the parameters of gamma regression by using two estimation methods which are The Maximum Likelihood and the Bayesian and a comparison between these methods by using the standard comparison of average squares of error (MSE), where the two methods were applied to real da

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Publication Date
Mon Apr 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Estimate AR(3) by Using Levinson-Durbin Recurrence & Weighted Least Squares Error Methods
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In this study, we investigate about the estimation improvement for Autoregressive model of the third order, by using Levinson-Durbin Recurrence (LDR) and Weighted Least Squares Error ( WLSE ).By generating time series from AR(3) model when the error term for AR(3) is normally and Non normally distributed and when the error term has ARCH(q) model with order q=1,2.We used different samples sizes and the results are obtained by using simulation. In general, we concluded that the estimation improvement for Autoregressive model for both estimation methods (LDR&WLSE), would be by increasing sample size, for all distributions which are considered for the error term , except the lognormal distribution. Also we see that the estimation improve

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Publication Date
Wed May 08 2024
Journal Name
Journal Of Mathematics And Computer Science
How does media coverage affect a COVID-19 pandemic model with direct and indirect transmission?
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In this paper, a compartmental differential epidemic model of COVID-19 pandemic transmission is constructed and analyzed that accounts for the effects of media coverage. The model can be categorized into eight distinct divisions: susceptible individuals, exposed individuals, quarantine class, infected individuals, isolated class, infectious material in the environment, media coverage, and recovered individuals. The qualitative analysis of the model indicates that the disease-free equilibrium point is asymptotically stable when the basic reproduction number R0 is less than one. Conversely, the endemic equilibrium is globally asymptotically stable when R0 is bigger than one. In addition, a sensitivity analysis is conducted to determine which

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Publication Date
Mon Dec 30 2024
Journal Name
Modern Sport
Mechanical angle foot during jumping and correct landing method
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This article investigates the relationship between foot angle and jump stability, focusing on minimizing injury risk. Here are the key points: Importance: Understanding foot angle is crucial for improving jump stability, athletic performance, and reducing jump-related injuries like ankle sprains. Ideal Foot Angle: Research suggests a forward foot angle of around 15 degrees might be ideal for many people during jumps. This angle distributes forces evenly across the foot, lowers the center of gravity, and provides more surface area for pushing off the ground. Factors Affecting Ideal Angle: The optimal angle can vary depending on the type of jump (vertical vs. long jump), fitness level, and personal preference. Incorrect Foot Angles: Landing w

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Publication Date
Fri Mar 17 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis and Characterization of [N-(4-Methoxybenzoyl amino)-thioxomethyl ]Methionine acid (MbM) and It's Complexes with Some Divalent Transition Metals Ions (Mn , Co , Ni , Cu , Zn , Cd and Hg)
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In this work , the ligand [N-(4-Methoxybenzoyl amino)-thioxomethyl] Methionine acid  has been synthesized by the reaction of 4- Methoxybenzoyl isothiocyanate with methionine acid . The metal complexes were prepared through the reaction of metals chlorides of Co(II) , Ni(II), Cu(II), Zn(II) and Cd(II) in ethanol as solvent . The ligand (MbM) and its metal complexes have been characterized by elemental analysis (CHNS), IR, 1H-13CNMR and UV- Vis spectra, magnetic susceptibility measurements, molar conductivity, melting points and atomic absorption. The metal-ligand ratio was determined by mole ratio method. The suggested structures for the Co(II), Ni(II), Cd(II) and Zn(II) complexes are tetrahedral geometry and  the Cu(II) complex

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Publication Date
Sun Mar 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
The Influence of x ratio and Annealing Temperatures on Structural and Optical Properties for (CuO)<sub>x</sub>(ZnO)<sub>1-x</sub> Composite Thin Films Prepared by PLD
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Abstract<p>Thin films of (CuO)<sub>x</sub>(ZnO)<sub>1-x</sub> composite were prepared by pulsed laser deposition technique and x ratio of 0≤ x ≤ 0.8 on clean corning glass substrate at room temperatures (RT) and annealed at 373 and 473K. The X-ray diffraction (XRD) analysis indicated that all prepared films have polycrystalline nature and the phase change from ZnO hexagonal wurtzite to CuO monoclinic structure with increasing x ratio. The deposited films were optically characterized by UV-VIS spectroscopy. The optical measurements showed that (CuO)<sub>x</sub>(ZnO)<sub>1-x</sub> films have direct energy gap. The energy band gaps of prepared thin films </p> ... Show More
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Publication Date
Sun Sep 01 2013
Journal Name
Baghdad Science Journal
Synthesis and Characterization of Novel Methyl 2-(1,7,7-Tri methylbicyclo[2.2.1]hept-2-yieldene)hydrazinecarbodithioate Schiff Bases Derived From Methylhydrazine carbodithioate And Their Bi(III) And Ag(II) Complexes
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Novel bidentate Schiff bases having nitrogen-sulphur donor sequence was synthesized from condensation of racemate camphor, (R)-camphor and (S)-camphor with Methyl hydrazinecarbodithioate (SMDTC). Its metal complexes were also prepared through the reaction of these ligands with silver and bismuth salts. All complexes were characterized by elemental analyses and various physico-chemical techniques. These Schiff bases behaved as uninegatively charged bidentate ligands and coordinated to the metal ions via ?-nitrogen and thiolate sulphur atoms. The NS Schiff bases formed complexes of general formula, [M(NS)2] or [M(NS)2.H2O] where M is BiIII or AgI, the expected geometry is octahedral for Bi(III) complexes while Ag(I) is expected to oxidized t

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Publication Date
Tue Jun 05 2018
Journal Name
Journal Of Molecular Structure
Synthesis, characterization, experimental and theoretical structure of novel Dichloro(bis{2-[1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-ylkN3] pyridine-kN})metal(II) compounds, metal ¼ Mn, Co and Ni
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The syntheses, characterizations and structures of three novel dichloro(bis{2-[1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II), [M(L)2Cl2], complexes (metal = Mn, Co and Ni) are presented. In the solid state the molecules are arranged in infinite hydrogen-bonded 3D supramolecular structures, further stabilized by weak intermolecular π…π interactions. The DFT results for all the different spin states and isomers of dichloro(bis{2-[1-phenyl-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II) complexes, [M(L1)2Cl2], support experimental measurements, namely that (i) d5 [Mn(L1)2Cl2] is high spin with S = 5/2; (ii) d7 [Co(L1)2Cl2] has a spin state of S = 3/2, (iii) d8 [Ni(L1)2Cl2] has a spin state of S =

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Publication Date
Sun Jan 01 2012
Journal Name
Advances In Physics Theories And Applications
Synthesis, Characterization, And Antibacterial Activities Of Manganese (II), Cobalt(II), Iron (II), Nickel (II) , zinc (II) And Cadmium(II) Mixed- Ligand Complexes Containing Amino Acid(L-Valine) And Saccharin
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new six mixed ligand complexes of some transition metal ions Manganese (II), Cobalt(II), Iron (II), Nickel (II) , and non transition metal ion zinc (II) And Cadmium(II) with L-valine (Val H ) as a primary ligand and Saccharin (HSac) as a secondary ligands have been prepared. All the prepared complexes have been characterized by molar conductance, magnetic susceptibility infrared, electronic spectral, Elemental microanalysis (C.H.N) and AA . The complexes with the formulas [M(Val)2(HSac)2] M= Mn (II) , Fe (II) , Co(II) ,Ni(II), Cu (II),Zn(II) and Cd(II) L- Val H= (C5H11NO2) , C7H5NO3S The study shows that these complexes have octahedral geometry; The metal complexes have been screened for their in microbiological activities against bacteria.

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Publication Date
Sat Sep 23 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Air Gap Width (S) and the Ratio (P1/D2) on .Minimum Projector Focal Length (Fp)min for the Double Pole-Piece Lens- at Costant Excitation (NI)
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The  spherical  double pole-piece  electron  lens i§ depend  on some

fact0rs : the-  minimum va}ue-of projector  fo·cal  length (Fp)i:J,Iill  â€¢  the

maximum value of  magnetic flux density (Bm) , the total  hal[ width

,(W)  o'f asyriunetrical   clln'e  of  magnetic field  distribution  [because there are differe_nt values of bore diameter  (D1) • i.                                           &

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