Mathematics
Chemistry
Physics
Mathematics
In this study, during the 1-parameter closed homothetic motion, the Holditch-Type Theorems are presented for the polar moments of inertia of the closed orbit curves of three non-collinear points.
In this study, we obtained some new post quantum-Hermite-Hadamard inequalities for differentiable convex function with critical point by using generalized (p, q)- Hermite-Hadamard Inequality. The perseverance of this article is to establish different results on the left-hand side of (p,q)-Hermite-Hadamard inequality for differentiable convex function along with critical point. Special cases were obtained for different (p, q)-Hermite Hadamard inequalies with the critical point c for some special values of q
The study suggests a class of product estimators for estimating the population mean of variable under investigation in simple random sampling without replacement (SRSWOR) scheme when secondary information on standard deviation, mean deviation, and quartile deviation is available. The expression for Bias and Mean Square Error (MSE) has been derived. A comparison is made both theoretically and numerically with other existing product estimators. It is concluded that compared to other product type estimators, suggested class of estimators estimate the population mean more efficiently.
In this paper, we apply an efficient method called the Homotopy perturbation transform method (HPTM) to solve systems of nonlinear fractional partial differential equations. The HPTM can easily be applied to many problems and is capable of reducing the size of computational work.
In this paper, we have proposed a new modified symmetric SOR method for numerical solutions of linear augmented system. We have also discussed the convergence criteria of this method along with optimal parameters. We will see that the new modified method has a higher rate of convergence with the help of an example. We are also presenting a comparison table with the other existing methods. All the computational work has been performed by MATLAB 2020R.
In this paper, the involute-evolute curve concept has been defined according to two type modified orthogonal frames at non-zero points of curvature and torsion in the Euclidean space E^3, respectively. Later, the characteristic theorems related to the distance between the corresponding points of these curves have been given. Besides, the relations have been found between the curvatures and also torsions of the two type the involute-evolute modified orthogonal pairs.
In this study, the first order nonlinear Volterra type integro-differential equations are used in order to identify approximate solutions concerning Euler polynomials of a matrix method based on collocation points. This method converts the mentioned nonlinear integro-differential equation into the matrix equation with the utilization of Euler polynomials along with collocation points. The matrix equation is a system of nonlinear algebraic equations with the unknown Euler coefficients. Additionally, this approach provides analytic solutions, if the exact solutions are polynomials. Furthermore, some illustrative examples are presented with the aid of an error estimation by using the Mean-Value Theorem and residual functions. The obtained results show that the developed method is efficient and simple enough to be applied. And also, convergence of the solutions of the problems were examined. In order to obtain the matrix equations and solutions for the selected problems, code was developed in MATLAB.
In real world physical applications purpose, it is complicated to acquire an exact solution of fuzzy differential equations due to complexities in fuzzy arithmetic and therefore creating the need for the use of reliable and efficient techniques in the solution of fuzzy differential equations. The purpose of this research paper is to utilize the reliable analytic approach of homotopy perturbation Sumudu transform method for better understanding of systems of non-linear fuzzy integro-differential equations, while using the concept of fuzzy parameter in certain dynamical problems to remove the hurdles faced in numerical approach. These mathematical models are of great interest in engineering and physics. Some numerical examples are also given to demonstrate the efficiency and superiority of the method, followed by graphical representation of the comparison of exact and approximated solution by using Maple 2017.
Unemployment is a serious problem for all over the world. It is a crucial task to endeavor with the unemployment for the welfare of the world. Once, the potential factors should be known to accomplish this task. The aim of this study is to investigate the determinants of the unemployment rates using fractional regression models for the 35 OECD (Organization for Economic Co-operation and Development) countries over the periods 2000-2017. We determined the factor affecting the unemployment rate by the fractional regression model using GMMbgw and GMMpre estimators for panel data. The empirical results revealed the significant determinants of unemployment as the result of the fractional regression models. Finally, we observe that saving rates, the growth rate of import and export are expressive on the unemployment rates.
In this present work we derived integral transforms such as Euler transform, Laplace transform, and Whittaker transform of K_4-function. The results are given in generalized Wright function. Some special cases of the main result are also presented here with new and interesting results. We further extended integral transforms derived here in terms of Gauss Hypergeometric function.
The exponential probability inequalities have been important tools in probability and statistics. In this paper, we prove a new tail probability inequality for the distri-butions of sums of conditionally linearly negative quadrant dependent (F-LNQD , in short) random variables, and obtain a result dealing with conditionally complete con-vergence of first-order autoregressive processes with identically distributed (F-LNQD) innovations.
The aim of this study is to investigate and interpret the geometric properties of the harmonic evolute surfaces of the tubular surfaces in Euclidean 3-space. For this purpose, the harmonic evolute surface is defined by considering the definitions and theorems for the tubular surface constructed in the Euclidean 3-space. The characterizations of the s and ψ parameter curves of the harmonic evolute surface obtained are examined, and then parameter curves of the tubular surface and harmonic evolute surface are compared. Finally, the harmonic evolute surface of a tubular surface is given an example and the graphics of these surfaces are drawn.
In this paper, we will recover the new generating functions of some products of Tribonacci Lucas numbers and orthogonal polynomials. The technic used her is based on the theory of the so called symmetric functions.
In the present paper, a numerical method is proposed to solve the time fractional Newel-Whitead-Segel equation subject to initial condition. This method is based d on the unification of conformable Sumudu transform (CST) and Adomian decomposition method (ADM), and then it is used to find the analytical solutions of linear-nonlinear fractional PDE’s. The test examples are given for illustration.
The main purpose of this research is to inquire the new solitary wave solution of the coupled time-fractional models to validate the influence and proficiency of the planned variational iteration method (VIM) using conformable derivative definition. Applications to four demanding nonlinear problems like Hirota-Satsuma coupled KdV equations, modified Boussinesq (MB) equation, approximate long wave (ALW) equation and Drinfeld-Sokolov-Wilson (DSW) equation demonstrate the efficiency and the robustness of the method. An analysis of the consequences with effects of relevant parameters and comparison with the exact solution presented with the help of graphs tables and gives the further understanding of numerical results by others. The convergence of the method is illustrated numerical and their physical significance is discussed.
Modeling and mathematical simulation are used in every field. To obtain improvement of relationship with customers is also used modeling. Relational marketing is not a choice, is a demand. The customers, which are emotionally related with the organization, will have more trust into it and will develop a strong commitment and a sustainable relationship, if the organization is more involved in keeping a positive and strong relationship with its customers and determine their value. The goal of this study is to bring in discussion the role and the importance of relationship with customers based on sustainable communication, customers being the main source of profit and value on long term for any company. To obtain this, was implemented a model of simulation and strategic communication, analysed through the prism of customers’ 360 degrees. Data were gathered from 100 customers and the results showed a strog relationship based on communication with its customers and the important role of employees in this relationship; the new technologies used in relationship with the customers, according to the literature, have a crucial role in attracting, retaining and growing the number of customers, but this study shows that is used at a very reduced level in the analysed organization. Mathematical simulation played an important role in discovering the right way through the maze of the new products and information present into the analysed supermarket based on continuous communication and relationship.
Chemistry
The use of pesticides is a common practice in modern agriculture. To increase and to ensure the security in people nutrition, two comparative chromatographic methods (GC-MS and HPLC-DAD) for fungicide residues detection and monitoring in some fruits and vegetables were tested. Some vegetables, eggplants, cucumbers, red potatoes, white potatoes, red peppers and fruits, plums, apples, lemons, grapes, clementines, were analyzed for fungicide residues quantification. The presence of Tebuconazole, Boscalid, Iprodione and Imazalil was followed and quantified in the tested samples. These analyses are important for environment and end-consumers protection. Generaly, both techniques are very sensitive and selective for the analysis of pesticides at low concentrations. GC-MS presents better linearity characteristics for Tebuconazole and Imazalil, but HPLC-DAD was the most rapid method. The tested products do not contain large fungicides quantities.
Oxicam derivatives play an important role in the treatment of pain and inflammation. The mechanism of action of these compounds consists in the inhibition of cyclooxygenase (COX) and the blockade of isoform 1 of this enzyme (COX-1) is considered to generate adverse effects. The aim of this paper is to establish which of the atoms in the oxicams molecules are responsible for their inhibitory activities, using electronegativity as fingerprint descriptor. Using this descriptor and molecular docking programs, the atoms in the molecule that have a greater contribution to COX-1 inhibition have been identified. In the case of the studied molecules, the oxygen atoms and the nitrogen atoms are highlighted. The oxygen atoms participate in the interaction as electron acceptors through U-MO molecular levels (74.1%) and the nitrogen atoms participate in the interaction both as a nucleophilic center through the molecular state of HOMO (13.7%) and as an electrophilic center through the molecular state of LUMO (13.2%). In the case of three out of four of the studied compounds, the 4-hydroxyl group of the thiazine ring participates in the interaction with COX-1. The results are also supported by the 2D and 3Ddiagrams of the applied docking method.
The present study was conducted to assess the carcinogenic and non-carcinogenic health risks of PAHs contamination in roasted plantain collected from three different locations within Osogbo metropolis, Nigeria. The PAHs were extracted using Soxhlet extraction technique with n-hexane and dichloromethane (3:1) as the extracting solvent. A column, packed with silica gel, was used for clean-up process and the levels of the targeted PAHs were determined by a gas chromatograph–flame ionization detector (GC-FID). The result revealed that the concentrations of total PAHs detected in the roasted samples at location A, B, C were 3.958 μg/kg, 3.654 μg/kg and 3.217 μg/kg. The HMW carcinogenic PAHs constitute about 32% of the total PAHs in the roasted plantain samples where benzo(a)pyrene, which is a marker for carcinogenicity, was found to be 9%. Comparing these results with the regulatory limits, all the analyzed roasted plantain samples were found below the maximum residual limit (MRL) of 5 μg/kg, but the calculated carcinogenic risk (CR) presented value greater than 1×10^-4, signifying health risk associated with the consumption of the roasted plantain. The major source of the PAHs using diagnostic ratios (Fla/Pyr and Ph/Ant) showed that the charcoal used in roasting is a major contributing factor to the high levels of PAHs detected in the roasted plantain samples.
A polyphenolic extract of Robinia pseudoacacia L. flowers was prepared using a hydro-ethanolic extraction phase. The chemical analysis of the extract consisted in the assessment of the total polyphenolic content (Folin-Ciocalteu method) and the flavonoid fingerprint of the extract determined by high-performance thin-layer chromatography (HPTLC). Two methods ferric reducing antioxidant power (FRAP) and radical scavenging activity with DPPH were used to measure the antioxidant activity of the extract. The cytotoxic and antitumor effects were evaluated on two cell lines: palatal mesenchymal stem cells (pMSCs) and epithelial cells derived from human cervical adenocarcinoma (HeLa (ATTC® CCL-2™)). The chemical content of Robinia pseudoacacia L. flowers extract reveals the presence of apigenin-7-glucoside and rutin. Results indicated high antioxidant activity with both methods (FRAP and DPPH). No cytotoxic effects of the extract were observed on the pMSCs cell line. The extract induced significant necrosis and apoptosis of the HeLa cells, proving an antitumor effect in vitro. The data confirm the antioxidant and antitumor effects of the polyphenols and the therapeutic potential of Robinia pseudoacaia flowers extract. In the last years, the therapeutic effect of the compounds from Robinia pseudoacacia flowers is less discussed; even the traditional medicine mentions them as helpful medicinal means. The present paper points out the correlation between Robinia pseudoacacia flowers polyphenolic compounds and their chemical and biological effects.
The dye-sensitized solar cells (DSSC) and thin-layer heterojunctional solar cells have attracted much attention as an alternative to relatively expensive silicon-based solar cells. Among the various photosensitizers used to build these cells, porphyrins have proven to be outstanding candidates due to their strong absorption in the visible region and have established basic and peripheral modification methods to adjust their geometry and electronic structures. Due to the improved spectral properties, the electronic spectra of these materials have been extensively studied. In this paper, the information obtained using both ultraviolet-visible (UV-VIS) and Fourier Transform Infrared (FTIR) spectroscopy have been used to evaluate the use of Pd-TPP (palladium-5,10,15,20-tetraphenyl porphyrin) as sensitizer dye on different glass substrate coated with transparent conducting oxides. The electrical characterization and quantum efficiency results, related with Pd-TPP-sensitized heterojunctional supramolecular solar cells, are also highlighted.
Physics
In the present work, two dimensional flow of a hyperbolic tangent fluid with chemical reaction and viscous dissipation near a stagnation point is discussed numerically. The analysis is performed in the presence of magnetic field. The governing partial differential equations are converted into non-linear ordinary differential equations by using appropriate transformation. The resulting higher order non-linear ordinary differential equations are discretized by finite difference method and then solved by SOR (Successive over Relaxation parameter) method. The impact of the relevant parameters is scrutinized by plotting graphs and discussed in details. The main conclusion is that the large value of magnetic field parameter and wiessenberg numbers decrease the streamwise and normal velocity while increase the temperature distribution. Also higher value of the Eckert number Ec results in increases in temperature profile.
We study the effect of Gaussian filter on the point spread function (psf) for a single hexagonal aperture for diffraction limit system and by inserting a coma aberration (w31=0.25 and 0.5). Also we derived the point spread function for a single hexagonal aperture and when there is a Gaussian filter with different values in width used. the different values of coma aberration was study ,we notice a decrease in intensity and secondary peaks of psf . The pulse to noise ratio increases with the width of the Gaussian filter increases.
This article represents an experiment for a portable open-source ECG monitoring system, purposed for isolated immunosuppressed patients, with heart conditions. At the current stage of development, the proposed experimental MCT (Mobile Cardiac Telemetry) system can be wirelessly used in conjunction with a smart phone and a real-time graph streaming application, through the BLE (Bluetooth Low Energy) module of an IoT embedded platform. At the moment, the system is intended for autonomous low power consumption and short wireless proximity range suited for close monitoring of patients by themselves at home, or by the medical staff in the isolated hospital ward rooms or mobile isolation containters.