Comparative Study of Tribological Properties of Multilayers Laminate Nanocomposites

Eman Ebrahim Nassar,Amal Ebrahim Nassar 한국고분자학회 2021 폴리머 Vol.45 No.5

Wear resistance studies for the multilayer laminate nanocomposite experimentally need a lot of time and money to investigate the effects of different parameters over it. Furthermore, the impact of these parameters on the surface occurs within a microsecond making the investigation very difficult. Statistical methods such as response surface methodology can be an effective technique in this matter. In the current work, the response surface methodology and the artificial neural network were used to design and analyze the weight loss at different temperatures, sliding speeds, applied loads, and weight percentages of graphene nanoplatelet (GNP) for multilayers laminate composite consists of polyurethane resin and anhydride hardener reinforced with 30 volume fraction of random fiber-glass. It was found that increasing GNP content could effectively increase friction coefficient and reduce the wear rate of multilayer laminate nanocomposite. The predicted values from artificial neural networks and experimental methods are found very close to each other.

Some examples of quasi-Armendariz rings

Ebrahim Hashemi 대한수학회 2007 대한수학회보 Vol.44 No.3

In [12], McCoy proved that ifR is a commutative ring, thenwhenever g(x) is a zero-divisor inR[x], there exists a nonzeroc 2 R suchthat cg(x) = 0. In this paper, rst we extend this result to monoid rings.Then for a monoid M , we give some examples of M -quasi-Armendarizrings which are a generalization of quasi-Armendariz rings. Every re-duced ring is M -quasi-Armendariz for any unique product monoid Mand any strictly totally ordered monoid ( M; ). AlsoT4(R) is M -quasi-Armendariz when R is reduced and M -Armendariz.

On χ⊗η-Strong Connes Amenability of Certain Dual Banach Algebras

Ebrahim Tamimi,Ali Ghaffari 한국수학교육학회 2024 純粹 및 應用數學 Vol.31 No.1

In this paper, the notions of strong Connes amenability for certain products of Banach algebras and module extension of dual Banach algebras is investigated. We characterize χ ⊗ η-strong Connes amenability of projective tensor product K⨶H via χ ⊗ η-σwc virtual diagonals, where χ ∈ K∗ and η ∈ H∗ are linear functionals on dual Banach algebras K and H, respectively. Also, we present some conditions for the existence of (χ, θ)-σwc virtual diagonals in the θ-Lau product of K ×_θ H. Finally, we characterize the notion of (χ, 0)-strong Connes amenability for module extension of dual Banach algebras K ⊕ X, where X is a normal Banach K-bimodule.

Efficient adsorption of Azure B onto CNTs/Zn:ZnO@Ni2P-NCs from aqueous solution in the presence of ultrasound wave based on multivariate optimization

Ebrahim Alipanahpour Dil,Mehrorang Ghaedi,Arash Asfaram,Fatemeh Mehrabi,Fardin Sadeghfar 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.74 No.-

This work devoted to the investigation of adsorption Azure B (Az-B) onto CNTs/Zn:ZnO@Ni2P-NCs, whiledependency of process efficiency to variables was optimized by the application response surfacemethodology. This adsorbent successfully using small amount 0.031 g is applicable to the adsorption ofthe high amount of Az-B in a short time. The optimum variables for achievement of maximum Az-Badsorption percentage (98.84%) were achieved using 0.031 g of CNTs/Zn:ZnO@Ni2P-NCs, 26.1 mg L 1initial Az-B concentration, 8.2 min sonication time and pH 6.3. The kinetic of Az-B adsorption followedpseudo-second-order kinetic and equilibrium data strongly follow the Langmuir model.

Numerical and Experimental Investigations of Trajectory Eff ects into Temperature Distribution and Distortion in the Slot Welding of Steel S235JR

Ebrahim Nateghi,Abdolhamid Gorji Volukola 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.3

One of the signifi cant factors that impresses on welded parts’ performance is welding trajectory. Slotted samples with loop and parallel trajectories welded by two steel plates by S235JR and GMAW process. Temperature distributions were registered by the four K type thermocouples. Heat aff ected zone dimensions were measured on polished and etched cross-sections of each sample. Induced distortions by dial indicators were gauged along welding process and cooling. To evaluate temperature fi eld and distortion in the welding process, three-dimensional FE models were performed. There was good agreement between the FE model predictions and experimental measurements. The most temperatures, distortions and induced longitudinal and transverse residual stresses by welding in the loop trajectory were more than the parallel.

Treatment Outcomes of Open Pelvic Fractures Associated with Extensive Perineal Injuries

Ebrahim Ghayem Hasankhani,Farzad Omidi-Kashani 대한정형외과학회 2013 Clinics in Orthopedic Surgery Vol.5 No.4

Background: The main causes of death in patients with open pelviperineal injuries are uncontrollable bleeding and pelvic sepsis. The aim of this study was to evaluate the management outcomes of open pelvic fractures associated with extensive perineal injuries. Methods: We retrospectively studied 15 cases with open pelvic fractures associated with extensive perineal injuries (urethral and anal canal laceration) admitted between August 2006 and September 2010. Mechanism of injury, Injury Severity Score, associated injuries, hemodynamic status on arrival, resuscitation and transfusion requirements, operative techniques, intra- and postoperative complications, length of intensive care unit and hospital stay, and mortality were recorded in a computerised database for further evaluation and analysis. Results: The male to female ratio was 12:3 with an average age of 38.6 years (ranged, 11 to 65 years). The average packed red blood cell units used were 8 units (ranged, 4 to 21 units). All patients were initially transferred to the operating room for colostomy, radical debridement and fixation of the pelvic fracture by an external fixator. One patient had acute renal failure, which improved with medical treatment and 2 patients (13.3%) died, one with type III anteroposterior compression fracture due to hemorrhagic shock and the other due to septicemia. Conclusions: Open pelvic fractures with extensive perineal injuries are associated with high mortality rates. Early diagnosis and appropriate treatment, including reanimation, colostomy, cystostomy, vigorous and repeated irrigation and debridement, and fixation by an external fixator can improve the outcomes and reduce the mortality rate

Skew power series extensions of $\alpha$-rigid p.p.-rings

Ebrahim Hashemi,Ahmad Moussavi 대한수학회 2004 대한수학회보 Vol.41 No.4

We investigate skew power series of alpha-rigid p.p.-rings,where alpha is an endomorphism of a ring R which is notassumed to be surjective. For an alpha-rigid ring R,R[[x;alpha]] is right p.p., if and only ifR[[x,x^{-1};alpha]] is right p.p., if and only if R is rightp.p. and any countable family of idempotents in R has a join inI(R).

On clean and nil clean elements in skew t.u.p.~monoid rings

Ebrahim Hashemi,Marzieh Yazdanfar 대한수학회 2019 대한수학회보 Vol.56 No.1

Let $R$ be an associative ring with identity, $M$ a t.u.p.~monoid with only one unit and $\omega : M \rightarrow {\rm End}(R)$ a monoid homomorphism. Let $R$ be a reversible, $M$-compatible ring and $\alpha=a_{1}g_{1}+\cdots+a_{n}g_{n}$ a non-zero element in skew monoid ring $R \ast M$. It is proved that if there exists a non-zero element $\beta=b_{1}h_{1}+\cdots+b_{m}h_{m}$ in $R \ast M$ with $\alpha\beta=c$ is a constant, then there exist $1 \leq i_{0} \leq n$, $1 \leq j_{0} \leq m$ such that $g_{i_{0}}=e=h_{j_{0}}$ and $a_{i_{0}}b_{j_{0}}=c$ and there exist elements $a, 0\neq r$ in $R$ with $\alpha r=ca$. As a consequence, it is proved that $\alpha \in R \ast M$ is unit if and only if there exists $1 \leq i_{0} \leq n$ such that $g_{i_{0}}=e, a_{i_{0}}$ is unit and $a_{j}$ is nilpotent for each $j \neq i_{0}$, where $R$ is a reversible or right duo ring. Furthermore, we determine the relation between clean and nil clean elements of $R$ and those elements in skew monoid ring $R \ast M$, where $R$ is a reversible or right duo ring.

Effects of different exercise modalities on novel hepatic steatosis indices in overweight women with type 2 diabetes

Ebrahim Banitalebi,Mohammad Faramarzi,Samira Nasiri,Majid Mardaniyan,Vahid Rabiee 대한간학회 2019 Clinical and Molecular Hepatology(대한간학회지) Vol.25 No.3

Background/Aims: Fatty liver is a clinical and pathologic condition in individuals with type 2 diabetes (T2D). The purpose of this study is to examine the effects of different exercise modalities on non-alcoholic fatty liver indices (fatty liver index [FLI], lipid accumulation product [LAP], hepatic steatosis index [HSI], and Framingham Steatosis Index [FSI]) in women with T2D. Methods: Fifty-two women with T2D and a mean age of 55.07±5.92 yrs, body mass index (BMI) 28.94±4.09 kg/m2, and hemoglobin A1c (HbA1c) 9.41±0.82% were randomized to a sprint interval training (SIT) (n=17), combined aerobic and resistance (A+R) training (n=17), or control group (n=18) for 10 weeks. Two-way repeated analysis of variance (ANOVA) was used to find differences between groups and the effects of time and Time×Group interactions after 10 weeks on non-alcoholic fatty liver indices. After this, ANOVA models were constructed to determine the effects of group allocation and change in non-alcoholic fatty liver indices. Results: There were significant time interactions for FLI (P<0.001), HSI (P<0.001), and LAP (P<0.001). Also, there were significant Time×Group interactions for fasting blood glucose (P=0.034), and HbA1c (P=0.006). Conclusions: Results highlight that exercise training, independent of mode of training, is an effective strategy to improve some indices related to hepatic steatosis and blood glucose profiles in women with T2D.

Highly efficient simultaneous biosorption of Hg2+, Pb2+ and Cu2+ by Live yeast Yarrowia lipolytica 70562 following response surface methodology optimization: Kinetic and isotherm study

Ebrahim Alipanahpour Dil,Mehrorang Ghaedi,Gholam Reza Ghezelbash,Arash Asfaram,Mihir Kumar Purkait 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.48 No.-

In this research, biosorption of Hg2+, Pb2+ and Cu2+ from aqueous solution via Yarrowia lipolytica 70562living mass was described. Correction and dependency of biosorption efficiency to effective variables likepH, initial Hg2+, Pb2+ and Cu2+ concentration, contact time and temperature was studied by centralcomposite design under response surface methodology. Three responses were simultaneously studied bynumerical optimization methodology. The optimum biosorption efficiency of Hg2+, Pb2+ and Cu2+ ions at18, 22 and 25 mg L 1 onto Y. lipolytica 70562 was found to be 99.26%, 101.15% and 99.74% at pH of 6.4 and25 C after around 8 h under well mixing. Finally, optimum condition for acceptable and repeatableagreement among experimental and real data was explored. The artificial neural network (ANN) modelwas used for predicting simultaneous biosorption of Hg2+, Pb2+ and Cu2+ ions based on experimental data. It was found that using ANN model with 12 neurons at hidden layer for all three ions, the R2 of 0.989 andMSE of 993 for Hg2+ ion were obtained. The R2 of 0.981 and MSE of 1.155 for Pb2+ ion were obtained andalso for Cu2+ ion the values of the R2 and MSE were found to be 0.971 and 1.589, respectively. Langmuirisotherm model was bestfitted with the equilibrium experimental. The experimental kinetic data wasrepresented well by using pseudo-second-order model and intraparticle diffusion model.