Volume 21 – Issue 3

In this paper, we give construction of quantum codes over F_q from cyclic codes over the F_q+uF_q+vF_q+wF_q+uvF_q, where u^2=u,v^2=v,w^2=w,uv=vu,uw=wu=vw=wv=0, q=p^m and p is an odd prime. We determine the parameters of quantum error correcting codes which constructed from cyclic codes over the F_q+uF_q+vF_q+wF_q+uvF_q. Finally, we give some examples of quantum codes.

We define the generalized (k, r) – Gauss Pell numbers by using the definition of a distance between numbers. Then we examine their properties and give some important identities for these numbers. In addition, we present the generating functions for these numbers and the sum of the terms of the generalized (k,r)- Gauss Pell numbers.

In this article, firstly, we have described new generalizations of generalized k-Horadam sequence and we named the generalizations as another generalized k-Horadam sequence {〖H^’〗_(k,n) }_(n∈N), a different generalized k-Horadam sequence {q_k,n} and an altered generalized k-Horadam sequence {Q_k,n}, respectively. Then, we have studied properties of these new generalizations and we have obtained generating function and extended Binet formula for each generalization. Also, we have introduced a power sequence for an altered generalized Horadam sequence in order to be used in different applications like number theory, cryptography, coding theory and engineering.

Statistical convergence is an active area, and it appears in a wide variety of topics. However, it has not been studied extensively in Riesz spaces. There are a few studies about the statistical convergence on Riesz spaces, but they only focus on the relationship between statistical and order convergences of sequences in Riesz spaces. In this paper, we introduce the notion of (V,λ)-order summable by using the concept of λ-statistical monotone and the λ-statistical order convergent sequences in Riesz spaces. Moreover, we give some relations between (V,λ)-order summable and λ-statistical order convergence.

The aim of the paper is to study the tangent bundle of Norden manifolds endowed with the complete lift of quarter-symmetric metric connection. Firstly, the complete lift of quarter-symmetric metric connection is obtained on tangent bundle of almost Norden manifold. Under the condition of integrability of structure, the almost Norden manifold endowed with the quarter-symmetric metric connection is shown to be Norden manifold.

In this paper, we compare the methods of estimation for one parameter lifetime distribution, which is a special case of inverse Gompertz distribution. We discuss five different estimation methods such as maximum likelihood method, least-squares method, weighted least-squares method, the method of Anderson-Darling, and the method of Crámer–von Mises. It is evaluated the performances of these estimators via Monte Carlo simulations according to the bias and mean-squared error. Furthermore, two real data applications are performed.

In this study, we define a new type of Pell and Pell-Lucas numbers which are called biGaussian Pell and biGaussian Pell-Lucas numbers. We also give the relationship between negabiGaussian Pell and Pell-Lucas numbers and bicomplex Pell and Pell-Lucas numbers. Moreover, we obtain the Binet’s formula, generating function, d’Ocagne’s identity, Catalan’s identity, Cassini’s identity and some sums formulas for these new type numbers. Some algebraic proporties of biGaussian Pell and Pell-Lucas numbers which are connected between biGaussian numbers and Pell and Pell-Lucas numbers are investigated. Moreover, we give the matrix representation of biGaussian Pell and Pell-Lucas numbers.

In this paper, we study Smarandache P_1B curves of biharmonic new type constant P_2-slope curves according to type-2 Bishop frame in the Sol space. Type-2 Bishop equations of Smarandache P_1B curves are obtained in terms of base curve’s type-2 Bishop invariants. Subsequently, we express some interesting relations.

Nano JD closed sets, a new class of Nano generalized closed sets in Nano topological spaces, relies on the g-interior and g closure operators. This paper aims to interpret and investigate its extension and connection with other existing concepts.

In this paper, the Adomian Decomposition Method (ADM) is employed in solving second order ordinary differential equation. Numerical algorithm was developed. The decomposition method provides a solution as an infinite series in which terms can easily be determined. It is observed that the method is practically suited for initial value problems. The method is effective and easy to implement. The results were presented in both tabular and graphical forms.

In this study, a matrix-collocation method is developed numerically to solve the linear Fredholm-Volterra-type functional integral and integro-differential equations. The linear functional integro-differential equations are considered under initial conditions. The mentioned type problems often appear in various branches of science and engineering such as physics, biology, mechanics, electronics. The method essentially is a collocation method based on the Lagrange polynomials and matrix operations. By using presented method, the problem is reduced to a system of linear algebraic equations. The solution of this system gives the coefficients of assumed solution. An error analysis based on the residual function is studied. Some examples are solved to demonstrate the accuracy and efficiency of the method.

In this study, the Serret-Frenet frame and derivative formulas were obtained for all intermediate points of the rational Bezier curves with the algorithm method, and much more general results were computed from the previous studies. In addition, the center and radius of the osculator circle and sphere were calculated.

In this paper, we discuss the existence and uniqueness of solutions for the coupled system of Phi-Caputo fractional differential equations. An illustrative example is included to show the applicability of our results.

There are a lot of structures in tangent and cotangent bundle. One of them is the Hsu – (4,2) structure have been defined and studied by Yano, Hough and Chen [1] and the complete and horizontal lifts of Hsu – (4,2) structure extended in M^n to cotangent bundle by R. Nivas and M. Saxena [2]. Hsu-structure had been defined firstly by Prof Mishra [3]. This paper consists of two main sections. In the first part, we find the integrability conditions by calculating Nijenhuis tensors of the complete and horizontal lifts of Hsu – (4,2) structure. Later, we get the results of Tachibana operators applied to vector and covector fields according to the complete and horizontal lifts of Hsu – (4,2) structure and the conditions of almost holomorfic vector fields in cotangent bundle T^* (M^n ). Finally, we have studied the purity conditions of Sasakian metric with respect to the lifts of Hsu – (4,2) structure. In the second part, all results obtained in the first section were investigated according to the complete and horizontal lifts of the Hsu – (4,2) structure in tangent bundle T^* (M^n ).

A basic goal of this paper is to calculate, Weyl curvature of R-flat (Ricci-flat) spray of isotropic curvature and a locally projectively R-flat (Ricci-flat) spray, which is a projective invariance. Besides, the equivalents of E ̅-curvature and H-curvature that are closely related to the mean Berwald curvature have been found for a locally projectively R-flat spray of isotropic curvature.

The stucco window in this study is kept in the stores of the Museum of Islamic Art in Cairo, Egypt, and bears the number 454/7. This window has been exposed to many damage factors, the most important of which is the fire that broke out in the museum in 2006 AD, in addition to the effect of the water that was used to extinguish the fire. This research aims to study the components of the window (stucco – glass – wood) and identify the transformations resulting from the effect of fire using optical microscopy, scanning electron microscopy coupled with EDX, X-ray diffraction, and infrared spectroscopy. In addition, the microbiological damage resulting from the moisture that saturates the plaster and wood was investigated.

The present paper is focused on the microclimatic investigation and weather-climatic phenomena matrix assessment, which can be generated for heritage objectives at different spatial and temporal resolutions, correlated with physicochemical analysis of the particulate matter (PM_2.5-10). In the literature the importance of atmospheric PM monitoring in the proximity of monuments is not yet sufficiently highlighted. In this respect, the microclimatic investigation of the Tropaeum Traiani Monument (Adamclisi, Romania) was performed to assess the suitability of a closed environment, located outdoors, according to the conservation requirements of heritage materials. The monitoring campaigns (four seasons, e.g., from summer of the year 2018 to spring of the year 2019) were carried out by non-invasive measuring equipment. The collected data were used to investigate the hygrothermal and chemical behavior inside and outside of Tropaeum Traiani Monument, built in 109, to assess the risks on the oldest structural material. Principal component analysis (PCA) was performed by IBM SPSS Statistics software to assess the similarities between the microclimatic parameters.

Thermoplastic polymeric materials used in the case of friction couplings with sliding movement such as guides, bearings, linear bearings, must have good tribological properties related to friction and wear. Indication of these characteristics is a convenient means for faster characterization of the tribological behavior of any pair of materials when operating conditions are changed. The paper presents a comparative study of the friction characteristics for two thermoplastic polymeric materials (Relamid B-10-FC and Turcit B Slydway) that slide on a metal surface in dry or oil-lubricated environments. The evolution of the coefficient of friction for a non-compliant and a conforming contact under different operating and lubrication conditions was analyzed. The experimental research was done on a stand of pin on disk tribological tests illustrating graphically the evolution of the coefficient of friction with the load, speed and time for different surface roughness. The values of the normal experimental forces used to act on the pin were: F_n1=0.5N, F_n2=1N, F_n3=5N, F_n4=10N. The rotational speed of the disc can be changed using a variable speed drive. Experimental sliding speeds were: v_1=0.02m/s,v_2=0.04m/s,v_3=0.06m/s și v_4=0.08m/s. The temperature and humidity of the experimental conditions were as well 18°…22° and 60…70%. Each experiment was evaluated for a period of 30 min. The results of this research can be used to design high-performance mechanical systems to improve the various mechanical processes in which friction phenomena occur.

The paper develops a model based on the finite element analysis of the crack initiation and propagation in the generation IV structural materials due to the liquid metal embrittlement (LME) phenomenon. The stress-strain experimental curves obtained at 400 ºC by testing in the liquid lead and air were converted as the Ramberg – Osgood constitutive equations by proposing a new method to obtain the strain hardening coefficient. To estimate the accuracy of prediction are used the residual and standardised residual in the context of regression analysis. Further, a model based on the Gurson–Tvergaard-Needleman approach (GTN) was set up to evaluate the crack initiation and propagation under the LME conditions. An application of the developed micro-mechanical model that predicts the crack initiation and propagation in the Compact –Tension (CT) specimen due to LME is performed. The model is practical in the structural integrity activities framework of the structural materials that will be used in the ALFRED demonstrator, which will be build-up at RATEN ICN, Romania.

The development of industrial automation has implicitly led to the improvement of electric drive systems, especially since such installations are the most common form of conversion of electricity into mechanical energy. The electric drive can be defined and studied only if we consider the whole assembly of which it is part, such as the automation of a technological production process. This paper describes the design and practical implementation of a laboratory stand with a teaching feature. The designed stand is a study support for various applications used in the industrial area, offering the possibility of experimentation on programming and parameterization of frequency converters in the laboratory of “Electrical machines and drives” of the Faculty of Electrical Engineering, Electronics and Information Technology at the University of Valahia from Targoviste.

A new analytical method for the evaluation of heat capacities of semiconductors (GeS, GeSe, GeTe, and SnS) has been proposed using the Einstein-Debye approximation. These formulae differ from the Debye model representations and they involve a combination of the Einstein and Debye approximations. The proposed method allows developing an increasing accuracy for the determination of the temperature dependent heat capacities of semiconductors GeS, GeSe, GeTe and SnS. The approach suggested in this study for calculation of heat capacities is very well suitable to determine other thermodynamical properties of materials. The temperature dependence of heat capacities of GeS, GeSe, GeTe and SnS semiconductors has been evaluated and shows a good agreement with literature at different temperature ranges.

In this paper, we formulate the steady hydromagnetic lid-driven cavity problem in a stream function-vorticity form for weakly electrically conducting Newtonian and non-Newtonian liquids. Then we solve them by using the concept of pseudo time derivative. The classical benchmark results of the Newtonian liquid are recovered as a limiting case and the inhibiting influence of the magnetic field on the Newtonian and non-Newtonian liquids’ flow field is clearly depicted through graphs. We also show certain aspects of the flow for the first time in tables.