Introduction : Obstructive Sleep Apnea (OSA) represents the complete or partial obstruction of the airway. Clinically OSA manifests as sleepiness during the day, heavy snoring, and waking up during the night due to lack of air. Obesity, gender and orthodontic anomalies are listed in the literature as the etiologic factor of OSA. Aim : This study aimed to find the correlation in the analyzed studies between OSA and orthodontic anomalies in non-obese adults. Material and methods : The electronic search of the database was performed (PubMed and Google Scholar) to find relevant articles that correlate orthodontic anomalies with OSA. Keywords included: obstructive sleep apnea, orthodontic anomalies, cephalometric analysis, impact, association, body mass index, obesity, adults, non-obesity. Included criteria: non-obesity, a study published from 1999-2019, a study in English, full text. Results : Two hundred papers included keywords. The number of papers that included the full set criteria was nine. These nine papers were analyzed in detail. Conclusion : Analyzed articles showed that there is a correlation between Obstructive sleep apnea (OSA) and orthodontics malocclusion in non-obese adults. by time of publication of articles, availability of research, a language in which they were published, and data relevance.

Based on previous research on energy efficiency of the buildings, particularly their cooling load capabilities we will develop a collection of machine learning methods for detecting buildings with best cooling load capabilities. This collection will study the influence of 8 input variables (relative compactness, surface area, wall area, roof area, overall height, orientation, glazing area, glazing area distribution) on one output parameter, that is cooling load of buildings. The results of this study support the practicability of using machine-learning software to estimate building parameters as a convenient and accurate approach, as long as the methods chosen are well suited for the type of data in question.

We develop a thermodynamically consistent continuum damage micromechanics model for the compressive failure of flax fiber composites. We used a micromechanics-based constitutive model reported recently [1]. It describes the microstructure of a unidirectional composite and captures the material behavior of the fiber and matrix constituents, respectively. The description has been formulated in the reference configuration (i.e. the undeformed state of the composite) and is therefore independent of fiber rotations that may appear during the deformation of the composite. A hyperelastic finite deformation plasticity with power law hardening [3] mimics the compressive elastic-plastic stress-strain response of the fiber (reported in [2]) and the matrix. The model has been extended to account for fiber damage, resulting in a thermodynamically consistent continuum damage micromechanics model. Our results indicate that fiber damage plays an utmost role in the compressive failure of flax fiber composites – it is a major determinant of the material’s compressive stress-strain response. X-ray Computed Tomography and Scanning Electron Microscopy show that fiber damage can be attributed to intra-fiber splitting and elementary fiber crushing.

Paper materials are natural composite materials where fibers are almost randomly distributed in a fiber network. Mechanical properties of fiber networks are known to be strongly controlled by fiberfiber interactions and single fiber properties. A fiber network is often modeled as a beam network where beam-to-beam interactions are treated as cohesive zones and single beams stretch indefinitely without breaking. The latter assumption is not physically correct and leads to an overprediction of the mechanical response of the beam network. In this work, we present a computational modeling framework for simulating beam failures and thereby closing the gap to physically based micromechanical modeling of paper and packaging products. Modeling beam failure is a challenging engineering problem. At the onset of failure, the tangent stiffness tensor projected in a direction normal to the surface of discontinuity (commonly referred to as the localization tensor) is singular, i.e. we have a bifurcation point and the problem is ill-posed. Another implication of ill-posedness for the numerical simulation after a spatial discretization is a pathological mesh dependency of the computed result. We use the ED-FEM where a failure process zone (FPZ) is introduced into a multi-scale continuum mechanics formulation (i.e. the material is split into a small scale and a large scale defining the FPZ and the bulk material, respectively), making the computed result mesh independent. The multi-scale nature of the ED-FEM enables an operator splitting implementation method as opposed to carrying out the computations of the nodal displacement vector and the displacement discontinuity vector simultaneously with the global loop where the global stiffness matrix would be singular at the onset of failure. We show that fiber failures and fiber-fiber bond failures can contribute to the observed elastoplastic stress-strain response of paper.