Solitons and other solutions of perturbed nonlinear Biswas–Milovic equation with Kudryashov’s law of refractive index

We analytically study the exact solitary wave solutions of the perturbed nonlinear Biswas–Milovic equation with Kudryashov’s law of refractive index, which describes the propagation of pulses of various types in optical fiber. We apply three efficient and reliable schemes, specifically, the simple equation method, the (G'/G)-expansion method, and the new Kudryashov method. These approaches lead to a range of solitons and other solutions comprising of the bright solitons, dark solitons, singular solitons, periodic, rational, and exponential solutions. These solutions are also presented graphically. Furthermore, all obtained solutions are verified by symbolic computations

Multi-objective optimization of three different SMA-LRBs for seismic protection of a benchmark highway bridge against real and synthetic ground motions

Many researchers have taken advantage of adding shape memory alloy (SMA) wires to base isolators to control displacements and residual deformations. In the literature, different arrangements of SMA wires wrapped around the rubber bearings can be found, as examples, straight, cross and double-cross arrangements. SMA wires with various configurations and radii lead to the different characteristics of the isolator system and thus various shear hysteresis. Therefore, the aim of this study is to evaluate the performance of these three SMA wire’s configurations in the seismic retrofitting of a benchmark highway bridge by implementing them in the bridge’s existing lead rubber bearings (LRB). This system is referred to as SMA-LRB isolator. Firstly, because of the crucial influence of the wire’s radius, this parameter is determined using a multi-objective optimization algorithm (non-dominated sorting genetic algorithm (NSGA)-II). This algorithm simultaneously minimizes the deck acceleration and mid-span displacement. Secondly, the optimized SMA-LRBs are implemented in the highway bridge and nonlinear dynamic analysis is conducted. For the nonlinear response history analysis, two strong ground motion records are selected from the PEER database, by studying the site’s conditions. In addition, ten synthetic ground acceleration time histories are generated. The result illustrates that the double-cross SMA-LRB reduces the maximum and residual displacements more than two other devices; however, it causes the largest base shear force and deck acceleration. Besides, the cross-configuration results in the least displacement reduction and has the least shear force and acceleration. To find SMA-LRB with the best overall performance, a multi-objective decision-making method is utilized and the straight SMA-LRB is recognized as the most effective isolator

Seismic assessment of a benchmark highway bridge equipped with optimized shape memory alloy wire-based isolators

In this paper, an evolutionary multi-objective optimization algorithm named NSGA-II was used to determine the optimum radius for shape memory alloy (SMA) wires employed in conjunction with the lead rubber bearing (LRB), referred to as an SMA-LRB isolator. This algorithm simultaneously minimizes the mid-span displacement and the base shear force. Then, the optimized SMA-LRBs were implemented in a benchmark bridge to reduce excessive displacements. The results obtained from the nonlinear dynamic analysis show that the implemented approach could effectively optimize the SMA-LRBs. These improved smart isolators can noticeably reduce the maximum displacements and residual deformations of the structure; meanwhile, the base shear and deck acceleration remain less than those of the non-isolated benchmark bridge. This isolator can reduce the maximum mid-span displacement of the bridge by up to 61%, and the mid-span residual deformations by up to 100%, compared to an uncontrolled isolated bridge under different ground motions. This optimized passive system was compared with nonlinear dampers, passive SMA dampers, and a negative stiffness device. The results indicate that the optimized SMA-LRB isolators are generally more successful in reducing and recovering displacements than the other controllers

A high-order nonlinear Schrödinger equation with the weak non-local nonlinearity and its optical solitons

Abstract The present paper explores a high-order nonlinear Schrodinger equation in a non-Kerr law media with the weak non-local nonlinearity describing solitons' propagation through nonlinear optical fibers. To this end, the real and imaginary parts of the model are firstly extracted using a wave variable transformation. The modified Kudryashov method and symbolic computations are then adopted to successfully retrieve optical solitons of the model. The results presented in the current study demonstrate the great performance of the modified Kudryashov method in handling high-order nonlinear Schrodinger equations

Sleep paralysis in medieval Persia – the Hidayat of Akhawayni (?–983 AD)

Among the first three manuscripts written in Persian, Akhawayni’s Hidayat al-muta’allemin fi al-tibb was the most significant work compiled in the 10th century. Along with the hundreds of chapters on hygiene, anatomy, physiology, symptoms and treatments of the diseases of various organs, there is a chapter on sleep paralysis (night-mare) prior to description and treatment of epilepsy. The present article is a review of the Akhawayni’s teachings on sleep paralysis and of descriptions and treatments of sleep paralysis by the Greek, medieval, and Renaissance scholars. Akhawayni’s descriptions along with other early writings provide insight into sleep paralysis during the Middle Ages in general and in Persia in particular

Synthesis and characterization of Zeolite/Fe3O4 nanocomposite by green quick precipitation method.

A green quick precipitation method was successfully used for synthesis of magnetic iron oxide nanoparticles (Fe3O4-NPs) on the surface of sodium/potassium type zeolite. Ferric chloride, ferrous chloride and sodium hydroxide aqueous solutions were used in the synthesis and coating of the Fe3O4-NPs on the surface of the zeolite to produce the zeolite/magnetic iron oxide nanocomposite (zeolite/Fe3O4 –NCs). The reaction was performed in aqueous suspension phase under the ambient condition as green chemistry method. Characterization with Fourier transforms infrared spectroscopy (FT‒IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDXF) and transmission electron microscopy (TEM) confirmed the formation of Fe3O4-NPs with mean particle sizes of 3.55±1.02 nm on the surface of the zeolite

Surgical Repair of Posterior Urethral Defects: Review of Literature and Presentation of Experiences

<p class="MsoNormal" style="margin: 0cm 0cm 0pt; direction: ltr; unicode-bidi: embed; text-align: left;"><span style="font-size: small;"><span style="font-family: Times New Roman;"><strong>Introduction: </strong>The main objective of the present review article was to study the different aspects of reconstructive surgery for posterior urethral defects by reviewing the published articles and presentation of our experiences in the reconstructive urology division at Shohada-e-Tajrish hospital. </span></span></p><p class="MsoNormal" style="margin: 0cm 0cm 0pt; direction: ltr; unicode-bidi: embed; text-align: left;"><span style="font-size: small;"><span style="font-family: Times New Roman;"><strong>Materials and Methods: </strong>The Medline was searched with the keywords of <em>posterior urethroplasty</em>, <em>end-to-end anastomosis</em>, <em>excisional urethroplasty</em>, <em>anastomotic urethroplasty</em>, <em>pelvic fracture</em>, <em>bulboprostatic anastomosis</em>, and <em>urethral repair</em>. The search was limited to papers published from 1980 to September 2008. We selected the relevant published articles in this database and also presented our experience at our reconstructive urology division. </span></span></p><p class="MsoNormal" style="margin: 0cm 0cm 0pt; direction: ltr; unicode-bidi: embed; text-align: left;"><span style="font-size: small;"><span style="font-family: Times New Roman;"><strong>Results: </strong>Of over 5000 search results, we selected 38 relevant articles with substantial contribution to the subject. Pelvic fracture due to accidents was the most common etiology of pelvic fracture urethral distraction defect that usually involved the membranous urethra. Surgical treatment of this disorder with perineal anastomotic urethroplasty was accompanied by a success rate of 82% to 95% in different studies. The most important complications of this surgery include urinary incontinence and impotence; however, the incidence of these complications has been reduced by using new surgical techniques. </span></span></p><strong><span style="font-size: 12pt; font-family: ">Conclusion: </span></strong><span style="font-size: 12pt; font-family: ">Complete preoperative assessment, the use of suitable reconstructive techniques, and in particular, the use of flexible cystoscopy can lead to acceptable outcomes of the surgical repair of pelvic fracture urethral distraction defects.</span&gt

Delayed Retropubic Urethroplasty of Completely Transected Urethra Associated With Pelvic Fracture in Girls

Introduction: The objective of the present study was to evaluate the results and the complications of delayed retropubic urethroplasty of completely transected urethra associated with pelvic fracture in girls. Materials and Methods: From 2002 to 2008, a total of 7 girls with complete urethral disruption after pelvic fracture were referred to our center and all of them underwent delayed retropubic urethroplasty with end-to-end anastomosis of the urethra. Results: Seven female patients with a median age of 6 years old underwent delayed end-to-end anastomosis. The median time to surgery was 6 months from the trauma. Voiding was normal after catheter removal in all of the patients. The median follow-up was 36 months. Three patients had mild stress urinary incontinence after catheter removal. Conclusion: There are some different strategies for management of complete urethral avulsion in females who have sustained pelvic fracture, including early realignment, bladder flaps, and end-to-end anastomosis. The strategy of delayed end-to-end anastomosis urethroplasty with retropubic approach is sound and produces acceptable results. The use of flexible cystoscope and omental flap is effective in achieving continence after urethroplasty in such cases

Multiple Soliton Solutions of the Sawada-Kotera Equation with a Nonvanishing Boundary Condition and the Perturbed Korteweg de Vries Equation by Using the Multiple Exp-Function Scheme

The Sawada-Kotera equation with a nonvanishing boundary condition, which models the evolution of steeper waves of shorter wavelength than those depicted by the Korteweg de Vries equation, is analyzed and also the perturbed Korteweg de Vries (pKdV) equation. For this goal, a capable method known as the multiple exp-function scheme (MEFS) is formally utilized to derive the multiple soliton solutions of the models. The MEFS as a generalization of Hirota’s perturbation method actually suggests a systematic technique to handle nonlinear evolution equations (NLEEs)