Analysis of the small oscillations of a heavy barotropic gas filling an elastic body with negligible density

OMS-Vol. 3 (2019), Issue 1, pp. 331 – 342 Open Access Full-Text PDF
Hilal Essaouini, Pierre Capodanno
Abstract: In this work, we study the small oscillations of a system formed by an elastic container with negligible density and a heavy barotropic gas (or a compressible fluid) filling the container. By means of an auxiliary problem, that requires a careful mathematical study, we deduce the problem to a problem for a gas only. From its variational formulation, we prove that is a classical vibration problem.
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A new modified Adomian decomposition method for nonlinear partial differential equations

OMA-Vol. 3 (2019), Issue 2, pp. 81 – 90 Open Access Full-Text PDF
Djelloul Ziane, Rachid Belgacem, Ahmed Bokhari
Abstract: In literature, there are many methods for solving nonlinear partial differential equations. In this paper, we develop a new method by combining Adomian decomposition method and Shehu transform method for solving nonlinear partial differential equations. This method can be named as Shehu transform decomposition method (STDM). Some examples are solved to show that the STDM is easy to apply.
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Analytical solution of isotropic rectangular plates resting on Winkler and Pasternak foundations using Laplace transform and variation of iteration method

EASL-Vol. 2 (2019), Issue 4, pp. 6 – 20 Open Access Full-Text PDF
M. G. Sobamowo, O. M. Sadiq, S. A. Salawu
Abstract: Dynamic analysis of isotropic thin rectangular plate resting on two-parameter elastic foundations is investigated. The governing system is converted to system of nonlinear ordinary differential equation using Galerkin method of separation. The Ordinary differential equation is analyzed using hybrid method of Laplace transform and Variation of iteration Method. The accuracies of the analytical solutions obtained are verified with existing literature and confirmed in good agreement. Thereafter, the analytical solutions are used for parametric studies. From the results, it is observed that, increase in elastic foundation parameters increases the natural frequency. Increase in aspect ratios increases the natural frequency. It is expected that the present study will add value to the existing knowledge in the field of vibration.
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A comparative analysis of the travelling salesman problem: Exact and machine learning techniques

ODAM-Vol. 2 (2019), Issue 3, pp. 23 – 37 Open Access Full-Text PDF
Jeremiah Ishaya, Abdullahi Ibrahim, Nassirou Lo
Abstract: Given a set of locations or cities and the cost of travel between each location, the task is to find the optimal tour that will visit each locations exactly once and return to the starting location. We solved a routing problem with focus on Traveling Salesman Problem using two algorithms. The task of choosing the algorithm that gives optimal result is difficult to accomplish in practice. However, most of the traditional methods are computationally bulky and with the rise of machine learning algorithms, which gives a near optimal solution. This paper studied two methods: branch-and-cut and machine learning methods. In the machine learning method, we used neural networks and reinforcement learning with 2-opt to train a recurrent network that predict a distribution of different location permutations using the negative tour-length as the reward signal and policy gradient to optimize the parameters of recurrent network. The improved machine learning with 2-opt give near-optimal results on 2D Euclidean with upto 200 nodes.
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Software quality assurance of cryocooler drive electronics software used in spacecraft

EASL-Vol. 2 (2019), Issue 4, pp. 1 – 5 Open Access Full-Text PDF
Savitha A, Sudeesh B, PrakashaRao P J V K S
Abstract: Software plays an important role in the ISRO space mission. Reliability of this software is vital to achieve zero defects in space systems and services. There are varieties of software used in realization of spacecraft. Mainly it is categorized into onboard, mission and ground software. Evaluation of this software is the major activity for a software quality assurance person. Software quality engineer has to certify the software based on system level requirements, mission requirements and functional requirements. All the hardware and software interactions also have to be verified. Risk management is the key factor for effective software management. Software life cycle activities are carried out based on ISRO software process document. Following these standards and guidelines helps to find the defects in the earlier phase of software development life cycle. This paper mainly describes the software quality assurance activities carried out for control drive electronics unit used in GSAT spacecraft. SQA activities complied against the IEEE12207 standards (ISPD-2) at ISRO level. Pulse Tube Cryocoolers are active cryogenic devices used to generate cryogenic temperatures in the 50K-80K range in a single stage. Cryocooler drive electronics unit generates identical drive to both the compressors of pulse tube cryocooler.
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Wiener index of uniform hypergraphs induced by trees

ODAM-Vol. 2 (2019), Issue 3, pp. 19 – 22 Open Access Full-Text PDF
Andrey Alekseevich Dobrynin
Abstract: The Wiener index \(W(G)\) of a graph \(G\) is defined as the sum of distances between its vertices. A tree \(T\) generates \(r\)-uniform hypergraph \(H_{r,k}(T)\) by the following way: hyperedges of cardinality \(r\) correspond to edges of the tree and adjacent hyperedges have \(k\) vertices in common. A relation between quantities \(W(T)\) and \(W(H_{r,k}(T))\) is established.
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ASpin-NMR data reporting tool

OJC-Vol. 2 (2019), Issue 2, pp. 9 – 14 Open Access Full-Text PDF
Francesco Sinopoli, Alessandro Sinopoli
Abstract: Nuclear Magnetic Resonance spectroscopy, commonly referred as NMR spectroscopy, is a widely used technique for determining the structure of organic compounds and metallorganic complexes. The NMR characterization process can be done automatically by specific tools integrated into the main NMR dedicated software, however it is commonly subjected to user’s interpretation therefore it still remains a manual process. In relationship with the number of signals to interpret and the complexity of the spectrum, the user usually spends between ten minutes and one hour to manually generate an NMR report, which can be clearly affected by typos or format mismatches. Here we report an Excel sheet-based NMR data reporting tool which, thanks to ad hoc macros, generates as output a formatted NMR report, ready to be directly pasted into any manuscript. ASpin tool leaves to the users the full possibility to interpret the spectrum in this way they can gain more experience in the interpretation process, without giving up the time saving.
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Effects of shear deformation and rotary inertia on the dynamics of anisotropic plates traversed by moving concentrated load

OMS-Vol. 3 (2019), Issue 1, pp. 310 – 321 Open Access Full-Text PDF
Olorunsola Oriola Niyi, Yomi Monday Aiyesimi, Mohammed Jiya, Abdulhakeem Yusuf, Gbolahan Bolarin
Abstract: The effects of shear deformation and rotary inertia on the dynamics of anisotropic plates traversed by varying moving load resting on Vlasov foundation is investigated in this work. The problem is solved for concentrated loads with simply supported boundary conditions. An analytic solution based on the Galerkin’s method is used to reduce the fourth order partial differential equation into a system of coupled fourth order differential equation and a modification of the Struble’s technique and Laplace transforms are used to solve the resulting fourth order differential equation. Results obtained indicate that shear deformation and rotary inertia have significant effect on the dynamics of the anisotropic plate on the Vlasov foundation. Solutions are obtained for both the moving force and the moving mass problems. From the graphical results obtained, the amplitude of vibrations of the plate under moving mass is greater than that of the moving force and increasing the value of rotary inertia \({R_0}\) reduces the amplitude of vibration of the plate. increasing the mass ratio increases the amplitude of vibration of the plate.
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A mathematical model of the effects of ascorbic acid on the onset of neurodegenerative diseases

OMS-Vol. 3 (2019), Issue 1, pp. 300 – 309 Open Access Full-Text PDF
Anuraag Bukkuri
Abstract: Several neurodegenerative diseases such as Alzheimer’s Disease (AD), Huntington’s Disease (HD), Parkinson’s Disease (PD), and Amyotrophic Lateral Sclerosis (ALS) as well as ischemic strokes all show signs of excess oxidative stress due to increased production of reactive oxygen species (ROS). The author here posits here that ascorbic acid (AA), commonly known as Vitamin C, can help prevent such neurodegenerative disorders. The author proposes a mathematical model that captures the biochemical dynamics between AA, dehydroascorbic acid (DHA), and ROS in the brain and performs simulations under control and neurodegenerative disease situations. Then, a variety of treatments using AA and DHA were proposed and simulated to examine their efficacy.
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