pisrt – Page 68

Synthesis of nickel nanoparticles by sol-gel method and their characterization

OJC-Vol. 2 (2019), Issue 1, pp. 16 – 20 Open Access Full-Text PDF

Aisha Shamim, Zaheer Ahmad, Sajid Mahmood, Umair Ali, Tariq Mahmood, Zamir Ahmad Nizami

Abstract: The under consideration study focuses on synthesis and characterization of Nickel oxide (NiO) nanoparticles. Nanosized Nickel oxide powder was successfully synthesized using a simple and low cast sol-gel method. This method is environment friendly requiring no expensive chemicals and is time saving. The sol-gel method was accompanied by the formation of precipitates which were dried and calcined at 550\(^{o}\)C to get nickel oxide nanoparticles. The synthesized nanopowder was characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDX).

Graphene oxide synthesis by facile method and its characterization

OJC-Vol. 2 (2019), Issue 1, pp. 11 – 15 Open Access Full-Text PDF

Farman ullah Khan, Sajid Mahmood, Zaheer Ahmad, Tariq Mahmood, Zamir Ahmad Nizami

Abstract: The graphene and graphene oxide are latest and advanced materials with wide applications in environment, medical applications, industries, defense applications. We have synthesized graphene oxide from graphite flakes by modifying Hummer method in which we used NaNO\(_{2}\) instead of NaNO\(_{3}\). Then we characterized our samples with X-Ray Diffractometry (XRD), Scanning-Electron Microscopy (SEM) and Fourier-Transform Infrared-Spectroscopy (FT-IR). These results confirmed the formation of graphene oxide also through this process. This graphene oxide can further be used for future applications in wastewater treatment and biomedical applications.

Synthesis, spectral evaluation and pharmacological screening of some sulfa drugs

OJC-Vol. 2 (2019), Issue 1, pp. 1 – 10 Open Access Full-Text PDF

Aziz-Ur-Rehman, Muhammad Athar Abbasi, Sabahat Zahra Siddiqui, Shahid Rasool, Sadia Jabeen, Amar Masood Joyia, Asma Salah-Ud-Din Gondal

Abstract: Sulfonamides are considered to be biologically active and an important class of pharmaceutical compounds. These constitute an important class of antimicrobials, antidiabetics, anticancer and diuretics. These were the first chemotherapeutic drugs introduced to the world but their rapidly developed resistance decreased their use. In the present work, N-(2/4-substitutedphenyl)-4-(substituted)benzenesulfonamide (3a-d) and N-(tetrahydrofuran-2-ylmethyl)-4-methylbenzenesulfonamide 3e were synthesized by the reaction of substituted aniline (1a-c) and tetrahydrofuran-2-ylmethanamine (1d) with substituted benzenesulfonyl chloride (2a-d) using 10% aqueous \(Na_{2}CO_{3}\) solution as a reaction medium. In the second step, the synthesized molecules 3a-e were allowed to react different alkyl/aralkyl halides (4a-j) to synthesize the target N-substituted compounds, 5a-z,aa,bb, using lithium hydride as an activator and N,N-dimethylformamide (DMF) as a reaction medium. All the synthesized compounds were characterized by using spectral techniques such as \(^{1}\)H-NMR, IR and EI-MS; and further examined for their anti-bacterial activities.

Uniform well-posedness and stability for fractional Navier-Stokes equations with Coriolis force in critical Fourier-Besov-Morrey spaces

OMA-Vol. 3 (2019), Issue 1, pp. 70 – 89 Open Access Full-Text PDF

Azzeddine El Baraka, Mohamed Toumlilin

Abstract: In this paper, we study the Cauchy problem of the fractional Navier-Stokes equations with Coriolis force in critical Fourier-Besov-Morrey spaces. By using the Fourier localization argument and the Littlewood-Paley theory, we get a local well-posedness results and global well-posedness results with small initial data belonging to the critical Fourier-Besov-Morrey spaces. Moreover; we prove that the corresponding global solution decays to zero as time goes to infinity, and we give the stability result for global solutions.

The smallest sum-connectivity index on trees with \(n\) vertices and \(k\) pendant vertices

ODAM-Vol. 2 (2019), Issue 2, pp. 23-30 Open Access Full-Text PDF

Yuedan Yao

Abstract: For a given connected graph \(G\) and a real number \(\alpha\), denote by \(d(u)\) the degree of vertex \(u\) of \(G\), and denote by \(\chi_{\alpha}(G)=\sum_{uv\in E(G)} \big(d(u)+d(v)\big)^{\alpha}\) the general sum-connectivity index of \(G\). In the present note, we determine the smallest general sum-connectivity index of trees (resp., chemical trees) together with corresponding extremal trees among all trees (resp., chemical trees) with \(n\) vertices and \(k\) pendant vertices for \(0<\alpha<1.\)

Cyclic-antimagic construction of ladders

EASL-Vol. 2 (2019), Issue 2, pp. 43-47 Open Access Full-Text PDF

Muhammad Awais Umar

Abstract: A simple graph \(G=(V,E)\) admits an \(H\)-covering if every edge in the edge set \(E(G)\) belongs to at least one subgraph of \(G\) isomorphic to a given graph \(H\). A graph \(G\) having an \(H\)-covering is called \((a,d)-H\)-antimagic if the function \(h:V(G)\cup E(G) \to \{1,2,\dots, |V(G)|+|E(G)| \}\) defines a bijective map such that, for all subgraphs \(H’\) of \(G\) isomorphic to \(H\), the sums of labels of all vertices and edges belonging to \(H’\) constitute an arithmetic progression with the initial term \(a\) and the common difference \(d.\) Such a graph is named as super \((a,d)-H\)-antimagic if \(h(V(G))= \{ 1,2,3,\dots,|V(G)|\}\). For \(d=0\), the super \((a,d)-H\)-antimagic graph is called \(H\)-supermagic. In the present paper, we study the existence of super \((a,d)\)-cycle-antimagic labelings of ladder graphs for certain differences \(d\).

Effect of filler on solid insulator surface and tracking length in high voltage systems

EASL-Vol. 2 (2019), Issue 2, pp. 37-42 Open Access Full-Text PDF

Irfanullah Khan, Muhammad Ahtasham Abid, Zahid Ullah, Arooj Rashid

Abstract: This paper presents the effect of different fillers on tracking length of electrical insulators. Insulator samples were prepared using polyester resin-c and were tested according to ASTM D2302. A standard test known as “Inclined plane test” is used to test the insulators after the application of high stresses. Track length of each sample is measured using a Polari scope. Track length of filler added insulators is compared to the insulator without filler and a significant change was noted among them.

Multilinear fractional integral with rough kernel on variable exponent Morrey-Herz spaces

OMS-Vol. 3 (2019), Issue 1, pp. 167-183 Open Access Full-Text PDF

Afif Abdalmonem, Omer Abdalrhman, Shuangping Tao

Abstract: In this article, we study a class of the multilinear fractional integral with rough kernel on Morrey-Herz space with \(p(\cdot), q(\cdot), \alpha(\cdot).\) By using the properties of the variable exponent spaces, the boundedness of the multilinear fractional integral operator is obtained on variable nonhomogeneous Morrey-Herz spaces \({MK}_{q(\cdot),p(\cdot)}^{\alpha(\cdot),\lambda}(\mathbb{R}^{n}).\)

First analytic solution for the oscillatory flow of a Maxwell’s fluid with annulus

OMS-Vol. 3 (2019), Issue 1, pp. 159-166 Open Access Full-Text PDF

Chaudry Masood Khalique, Rabia Safdar, Madeeha Tahir

Abstract: The major purpose of this article is to discuss the oscillatory flow of an incompressible viscous Maxwell fluids (IVMF) between two infinite coaxial of circular pipes. In the case when time \(t=0\) the inner pipe is lying at rest where as at \(t>0\) the inner pipe of the annulus starts to oscillate along the common axis of the pipes. The analytical solutions of the problem are obtained via integral transformation technique which is beneficial for time dependent problems. Moreover, the derived solutions are given under the series form of the generalized \(G\) functions satisfying all the imposed auxiliary conditions whereas, the solutions for ordinary Maxwell and Newtonian fluids appear as the limiting case of the present obtained results. We include graphical comparison between Maxwell and Newtonian fluid, and we also explored the effects of different physical parameters on the fluid motion.

Positive solutions for nonlinear Caputo-Hadamard fractional differential equations with integral boundary conditions

OMA-Vol. 3 (2019), Issue 1, pp. 61-69 Open Access Full-Text PDF

Abdelouaheb Ardjouni, Ahcene Djoudi

Abstract: We study the existence and uniqueness of positive solutions of the nonlinear fractional differential equation with integral boundary conditions \(\mathfrak{D}_{1}^{\alpha }x\left( t\right) =f\left( t,x\left( t\right) \right) ,\;\;\; 1<t\leq e, x\left( 1\right) =\lambda \int_{1}^{e}x\left( s\right) ds+d,\) where \(\mathfrak{D}_{1}^{\alpha }\) is the Caputo-Hadamard fractional derivative of order \(0<\alpha \leq 1\). In the process we convert the given fractional differential equation into an equivalent integral equation. Then we construct an appropriate mapping and employ the Schauder fixed point theorem and the method of upper and lower solutions to show the existence of a positive solution of this equation. We also use the Banach fixed point theorem to show the existence of a unique positive solution. Finally, an example is given to illustrate our results.

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