Search results for "Variable"

Heterogeneous structures studied by an interphase elasto-plastic damaging model

2013

Heterogeneous materials present a mechanical response strongly dependent on the static and kinematic phenomena occurring in the constituents and at their joints. At the mesoscopic level the interaction between the units is simulated by mean of apposite mechanical devices such as the zero thickness interface model where contact tractions and displacement discontinuities are the primary static and kinematic variables respectively. In heterogeneous materials the response also depends on joint internal stresses. The introduction of internal stresses brings to the interphase model or an enhancement of the classical zero-thickness interface. With the term 'interphase' we shall mean a layer separa…

A non-linear Ritz method for progressive failure analysis of variable angle tow composite laminates

2022

A Ritz formulation for non-linear analysis of damage initiation and evolution in variable angle tow composite plates under progressive loading is presented. The model is built on a few key items. It assumes first order shear deformation theory kinematics and non-liner strains in the von Karman sense. The constitutive relationships are formulated in the framework of continuum damage mechanics at the ply level, so that each laminate layer can experience in-plane damage initiation and evolution, then reflected in material softening and loss of local stiffness. A Ritz polynomial expansion of the primary variables and the minimization of the total potential energy provide the discrete solution e…

The Mediating Role of Orthorexia in the Relationship between Physical Activity and Fear of COVID-19 among University Students in Poland

2021

Previous research showed that the COVID-19 pandemic has a significant impact on the wellbeing and lifestyle of populations worldwide, including eating and physical activity (PA) patterns. The present study aims to examine the mediating effect of orthorexia on the relationship between PA and fear of COVID-19. A sample of 473 university students from Poland of a mean age of 22 years (M = 22.04, SD = 2.90, 47% of women) participated in the cross-sectional online survey study. Continuous variables were measured using the Fear of COVID-19 Scale (FCV-19S) and the Test of Orthorexia Nervosa (TON-17), while categorical variables divided participants into the physically active and inactive group reg…

Efecto de supresión y mediación en el contexto de la intervención psicosocial: Diferencias, similitudes y ejemplos

2013

ResumenEl presente trabajo compara el efecto mediador y el supresor de una tercera variable. Ambos efectos parcelan la varianza de la variable dependiente (Y). La mediación es la reducción, tras introducir una tercera variable (Z) en el modelo, de la proporción de varianza explicada directamente por la variable independiente (X) en la variable criterio (Y) y la supresión es el incremento de la proporción de varianza explicada directamente por la independiente en la variable criterio, al incluir la tercera variable en el modelo. Se analizan las características y diferencias de cada efecto y se examina en qué situaciones se produce uno u otro. Cada situación, compuesta de tres variables corre…

2018

In recent decades, the massification and diversification of higher education have generated new challenges for the guidance of university students. The present study focuses on students’ experience...

The Magdalenian harpoons from the Iberian Mediterranean, based on pieces from Cova de les Cendres (Teulada-Moraira, Valencian region)

2012

Abstract Harpoons are one of the most characteristic implements of the Upper Magdalenian. However, morphologic differences in barbs and bases mark different regional traditions. This paper gives an account of the main features of harpoons in the Iberian Mediterranean, based on findings from Cova de les Cendres, and compares them with those found in other areas in Western Europe. The specificities of Mediterranean harpoons (a single range of barbs, variable length and number of barbs, and lack of hafting devices on the base) are considered in discussion of their potential functions and possible hafting systems.

Scale effects on plot runoff and soil erosion in a mediterranean environment

2017

Explaining scale effects for runoff and erosion improves our understanding of hydrological and erosion processes. In this investigation, plot-scale effects on event runoff per unit area, Qe, sediment concentration, Ce, and soil loss per unit area, SLe, were checked at the Sparacia (Italy) site. Similar information on the scale effects was obtained with different dependent variables, i.e., individual values of Qe, Ce, and SLe for each plot or the mean of their replicated values, and scale indicators, i.e., plot length, l, or plot area, A. The most common result, occurring for 57 to 62% of the events depending on the considered variable, was the lack of any scale effect. When scale effects we…

Riesz fractional integrals and complex fractional moments for the probabilistic characterization of random variables

2012

Abstract The aim of this paper is the probabilistic representation of the probability density function (PDF) or the characteristic function (CF) in terms of fractional moments of complex order. It is shown that such complex moments are related to Riesz and complementary Riesz integrals at the origin. By invoking the inverse Mellin transform theorem, the PDF or the CF is exactly evaluated in integral form in terms of complex fractional moments. Discretization leads to the conclusion that with few fractional moments the whole PDF or CF may be restored. Application to the pathological case of an α -stable random variable is discussed in detail, showing the impressive capability to characterize…

Un enfoque alternativo para la medicion del riesgo de interes en el ámbito de la renta variable

2002

Roman.Ferrer@uv.es El presente trabajo se plantea como objetivo primordial la derivación de una fórmula teórica de validez general para la duración de las acciones que supere las principales limitaciones de las tradicionales medidas de la duración obtenidas en el ámbito del Modelo del Descuento de Dividendos (DDM) en su versión simplificada de crecimiento constante. Con tal fin, se presta una atención preferente a las posibles interrelaciones existentes entre la tasa de crecimiento de los dividendos de las acciones y los tipos de interés nominales. En esencia, la medida de la duración generada con este enfoque alternativo se caracteriza básicamente por la incorporación de un factor de ajust…

Insights into archaeological human sample microbiome using 16S rRNA gene sequencing

2017

Human body is inhabited by a vast number of microorganisms, collectively known as human microbiome, and there is a tremendous interest in evolutionary changes of human microbial ecology, diversity and function. The field of paleomicrobiology – study of ancient human microbiome – is powered by modern techniques of Next Generation Sequencing (NGS), which allows extracting microbial genomic data directly from archaeological sample of interest. One of the major techniques is 16S rRNA gene sequencing, by which certain 16S rRNA gene hypervariable regions are being amplified and sequenced. However, some limitations of this method exist including taxonomic precision and efficacy of different region…