The role of personal resources in the JD-R model within a student-university context

“A research project submitted in partial fulfilment of the requirements for the degree of MA by Coursework and Research in the field of Industrial/Organisational Psychology in the Faculty of Humanities, University of the Witwatersrand, Johannesburg, 15 March 2016.”Student well-being has become an increasing concern for universities both locally and internationally, with an increased interest in the prevention of academic burnout and the promotion of academic engagement due to their respective negative and positive influence on students. Accordingly, the Job Demands-Resource (JD-R) model was developed as a theoretical framework, incorporating environmental characteristics that predict symptoms of engagement and burnout in individuals. A major criticism of the JD-R model is its lack of consideration for the impact of personal resources on individual well-being. Emanating from this concern, the current study used the Conservation of Resources (COR) theory to empirically investigate whether the personal resource of Psychological Capital (PsyCap) interacted within the health impairment and motivation processes of the JD-R model. More specifically, it examined whether PsyCap mediated the relationship between demands/resources and burnout/engagement within a South African university environment. Few studies have attempted to integrate personal resources into the JD-R model, and no known studies have applied this integration within a student-university context. This provides a unique and novel context for application, warranting further research. Research participants either accessed an online questionnaire via a web link made available to them on the university’s student portal, or a hard copy version of the questionnaire was distributed during lecture time. The questionnaire included a self-developed demographic questionnaire, an adapted version of the Student Stress Scale (Da Coste Leite & Israel, 2011), an adapted version of the Factors of Academic Facilitators Scale (Salanova, Schaufeli, Martinez, & Breso, 2010), the Maslach Burnout Inventory-Student Scale (Schaufeli, Salanova, Gonzalez-Roma, & Bakker, 2002), the Utrecht Work Engagement Scale-Student (Schaufeli, Salanova, et al., 2002), and the Psychological Capital Questionnaire (Luthans Avolio, Avey, & Norman, 2007; Luthans, Youssef, & Avolio, 2007). The final sample (N=331) consisted of both full-time and part-time undergraduate students in their first, second or third year of study at the University of the Witwatersrand, Johannesburg, South Africa.” “Results of the current study demonstrated that PsyCap mediated the relationship between academic obstacles and academic engagement, as well as, the relationship between academic facilitators and academic engagement. It also demonstrated, however, that PsyCap was not significantly related to academic burnout, and therefore was not a mediator in the relationship between academic obstacles/facilitators and academic burnout. Furthermore, results indicated that direct, positive relationships between academic obstacles and academic burnout; academic facilitators and PsyCap; and PsyCap and academic engagement existed, while a direct, negative relationship between academic obstacles and PsyCap existed. These findings were supported with previous research and literature. In addition, the current study also produced some non-hypothesised, but not unexpected, findings. Firstly, academic burnout and engagement was found to be moderately and negatively related, and secondly, engagement appeared to mediate the relationship between PsyCap and academic burnout. Additionally, an indirect, positive and weak relationship was found to exist between academic obstacles and burnout, while an indirect, negative and weak relationship was found between academic facilitators and academic burnout”. In conclusion, the current findings provide support for JD-R and COR theoretical assumptions, as well as the significant role personal resources play in the JD-R model in predicting student well-being.MT201

Factorization method for solving nonlocal boundary value problems in Banach space

This article deals with the factorization and solution of nonlocal boundary value problems in a Banach space of the abstract form B1 u = A u - S Φ( u )- G Ψ(A0 u) = f, u ∈ D (B1) , where A, A0 are linear abstract operators, S, G are vectors of functions, Φ, Ψ are vectors of linear bounded functionals, and u, f are functions. It is shown that the operator B1 under certain conditions can be factorized into a product of two simpler lower order operators as B 1 = BB0. Then the solvability and the unique solution of the equation B1 u = f easily follow from the solvability conditions and the unique solutions of the equations Bv = f and B0 u = v. The universal technique proposed here is essentially different from other factorization methods in the respect that it involves decomposition of both the equation and boundary conditions and delivers the solution in closed form. The method is implemented to solve ordinary and partial Fredholm integro-differential equations

Factorization method for solving nonlocal boundary value problems in Banach space

This article deals with the factorization and solution of nonlocal boundary value problems in a Banach space of the abstract form B1u = Au − SΦ(u) − GΨ(A0u) = f, u ∈ D(B1),where A, A0 are linear abstract operators, S, G are vectors of functions, Φ, Ψ are vectors of linear bounded functionals, and u, f are functions. It is shown that the operator B1 under certain conditions can be factorized into a product of two simpler lower order operators as B1 = BB0. Then the solvability and the unique solution of the equation B1u = f easily follow from the solvability conditions and the unique solutions of the equations Bv = f and B0u = v. The universal technique proposed here is essentially different from other factorization methods in the respect that it involves decomposition of both the equation and boundary conditions and delivers the solution in closed form. The method is implemented to solve ordinary and partial Fredholm integro-differential equations

A higher order control volume based finite element method to prodict the deformation of heterogeneous materials

Materials with obvious internal structure can exhibit behaviour, under loading, that cannot be described by classical elasticity. It is therefore important to develop computational tools incorporating appropriate constitutive theories that can capture their unconventional behaviour. One such theory is micropolar elasticity. This paper presents a linear strain control volume finite element formulation incorporating micropolar elasticity. Verification results from a micropolar element patch test as well as convergence results for a stress concentration problem are included. The element will be shown to pass the patch test and also exhibit accuracy that is at least equivalent to its finite element counterpart

Buckling and vibration analysis of laminated composite plate/shell structures via a smoothed quadrilateral flat shell element with in-plane rotations

This paper presents buckling and free vibration analysis of composite plate/shell structures of various shapes, modulus ratios, span-to-thickness ratios, boundary conditions and lay-up sequences via a novel smoothed quadrilateral flat element. The element is developed by incorporating a strain smoothing technique into a flat shell approach. As a result, the evaluation of membrane, bending and geometric stiffness matrices are based on integration along the boundary of smoothing elements, which leads to accurate numerical solutions even with badly-shaped elements. Numerical examples and comparison with other existing solutions show that the present element is efficient, accurate and free of locking

Multisurface plasticity for Cosserat materials: plate element implementation and validation

International audienceThe macroscopic behaviour of materials is affected by their inner micro-structure. Elementary considerations based on the arrangement, and the physical and mechanical features of the micro-structure may lead to the formulation of elastoplastic constitutive laws, involving hardening/softening mechanisms and non-associative properties. In order to model the non-linear behaviour of micro-structured materials, the classical theory of time-independent multisurface plasticity is herein extended to Cosserat continua. The account for plastic relative strains and curvatures is made by means of a robust quadratic-convergent projection algorithm, specifically formulated for non-associative and hardening/softening plasticity. Some important limitations of the classical implementation of the algorithm for multisurface plasticity prevent its application for any plastic surfaces and loading conditions. These limitations are addressed in this paper, and a robust solution strategy based on the Singular Value Decomposition technique is proposed. The projection algorithm is then implemented into a finite element formulation for Cosserat continua. A specific finite element is considered, developed for micropolar plates. The element is validated through illustrative examples and applications, showing able performance

Multiscale analysis of materials with anisotropic microstructure as micropolar continua

Multiscale procedures are often adopted for the continuum modeling of materials composed of a specific micro-structure. Generally, in mechanics of materials only two-scales are linked. In this work the original (fine) micro-scale description, thought as a composite material made of matrix and fibers/particles/crystals which can interact among them, and a scale-dependent continuum (coarse) macro-scale are linked via an energy equivalence criterion. In particular the multiscale strategy is proposed for deriving the constitutive relations of anisotropic composites with periodic microstructure and allows us to reduce the typically high computational cost of fully microscopic numerical analyses. At the microscopic level the material is described as a lattice system while at the macroscopic level the continuum is a micropolar continuum, whose material particles are endowed with orientation besides position. The derived constitutive relations account for shape, texture and orientation of inclusions as well as internal scale parameters, which account for size effects even in the elastic regime in the presence of geometrical and/or load singularities. Applications of this procedure concern polycrystals, wherein an important descriptor of the underlying microstructure gives the orientation of the crystal lattice of each grain, fiber reinforced composites, as well as masonry-like materials. In order to investigate the effects of micropolar constants in the presence of material non central symmetries, some numerical finite element simulations, with elements specifically formulated for micropolar media, are presented. The performed simulations, which extend several parametric analyses earlier performed [1], involve two-dimensional media, in the linear framework, subjected to compression loads distributed in a small portion of the medium

A unified formulation of analytical and numerical methods for solving linear fredholm integral equations

This article is concerned with the construction of approximate analytic solutions to linear Fredholm integral equations of the second kind with general continuous kernels. A unified treatment of some classes of analytical and numerical classical methods, such as the Direct Computational Method (DCM), the Degenerate Kernel Methods (DKM), the Quadrature Methods (QM) and the Projection Methods (PM), is proposed. The problem is formulated as an abstract equation in a Banach space and a solution formula is derived. Then, several approximating schemes are discussed. In all cases, the method yields an explicit, albeit approximate, solution. Several examples are solved to illustrate the performance of the technique. © 2021 by the author. Licensee MDPI, Basel, Switzerland

Approximate Solution of Fredholm Integral and Integro-Differential Equations with Non-Separable Kernels

This chapter deals with the approximate solution of Fredholm integral equations and a type of integro-differential equations having non-separable kernels, as they appear in many applications. The procedure proposed consists of firstly approximating the non-separable kernel by a finite partial sum of a power series and then constructing the solution of the degenerate equation explicitly by a direct matrix method. The method, which is easily programmable in a computer algebra system, is explained and tested by solving several examples from the literature. © 2022, Springer Nature Switzerland AG

Factorization and Solution of Linear and Nonlinear Second Order Differential Equations with Variable Coefficients and Mixed Conditions

This chapter deals with the factorization and solution of initial and boundary value problems for a class of linear and nonlinear second order differential equations with variable coefficients subject to mixed conditions. The technique for nonlinear differential equations is based on their decomposition into linear components of the same or lower order and the factorization of the associated second order linear differential operators. The implementation and efficiency of the procedure is shown by solving several examples. © 2021, Springer Nature Switzerland AG