Search results for "Automotive Engineering."

Insufficient control of heart rate in stable coronary artery disease patients in Latvia

2014

Background and objective:\ud Heart rate (HR) ≥70 beats per minute (bpm) increases cardiovascular risk in coronary artery disease (CAD) patients. The objective of the analysis is to characterize HR as well as other clinical parameters in outpatients with stable CAD in Latvia.<p></p>\ud \ud Materials and methods:\ud CLARIFY is an ongoing international registry of outpatients with established CAD. Latvian data regarding 120 patients enrolled in CLARIFY and collected at baseline visit during 2009–2010 were analyzed.<p></p>\ud \ud Results:\ud The mean HR was 67.7 ± 9.5 and 66.9 ± 10.7 bpm when measured by pulse palpation and electrocardiography, respectively. HR &#8…

The comparison of knee osteoarthritis treatment with single-dose bone marrow-derived mononuclear cells vs. hyaluronic acid injections

2017

Objective: The aim of this study was to compare treatment methods of the knee joint degenerative osteoarthritis, using autologous bone marrow-derived mononuclear cells and hyaluronic acid injections and observe prevalence of adverse effects in both groups. Materials and methods: A prospective randomized controlled clinical trial was carried out. The analysis of pain and changes in osteoarthritis symptoms after a single intra-articular bone marrow-derived mononuclear cell injection into the knee joint in the Kellgren– Lawrence stage II–III osteoarthritis during the 12-month period were performed. The results were compared with the control group treated routinely by hyaluronic acid injections…

Angels carrying crowns on the images of martyrs. Origin of the iconographic type

2013

Este artículo pretende explicar el origen de las imágenes de los ángeles portando coronas a los mártires, señalando para ello la relación de las coronas con los mártires desde la época paleocristiana, cómo éstas empezaron a ser portadas por ángeles, y los diferentes tipos de coronas que pueden portar según las distintas épocas. This article tries to explain the origin of the images of angels carrying crowns to the martyrs; to this end, it points out the relationship of the crowns with the martyrs from Early Christian period, the way these crowns began to be carried by angels, and the different types of crowns they could carry depending on different periods.

NOX reduction and efficiency improvements by means of the Double Fuel HCCI combustion of natural gas–gasoline mixtures

2016

Abstract Homogeneous Charge Compression Ignition (HCCI) and Double Fuel (DF) combustion represent two innovative processes sharing a strong potential for pollutant emissions and fuel consumption reduction. HCCI regards the auto-ignition of a homogeneous premixed charge of air and fuel, featuring very low NOX emissions and good efficiency. Double Fuel (DF) instead indicates the simultaneous combustion of gasoline and natural gas (or gasoline and LPG), premixed with air by the port injection of both fuels within same engine cycle. Since fuel mixtures enhances the HCCI performances widening the range of possible operating conditions, the authors tested the HCCI combustion process using natural…

The Experimental Validation of a New Thermodynamic Method for TDC Determination

2007

In-cylinder pressure analysis is becoming more and more important both for research and development purpose and for control and diagnosis of internal combustion engines; directly measured by means of a combustion chamber pressure transducers or evaluated by analysing instantaneous engine speed [1,2,3,4], incylinder pressure allows the evaluation of indicated mean effective pressure (IMEP), combustion heat release, combustion phase, friction pressure, etc...It is well known to internal combustion engine researchers that for a right evaluation of these quantities the exact determination of Top Dead Centre (TDC) is of vital importance: a 1° error on TDC determination can lead to evaluation err…

Impact behaviour of flax/epoxy composite plates

2015

This paper presents an experimental investigation of the impact behaviour of flax/epoxy composite plates submitted to low-velocity transverse impact. Low energy drop-weight impact tests have been performed on two types of quasi-isotropic flax/epoxy composites, rectangularly shaped with edges lengths of 142 mm × 94 mm and 2.85 mm thick. Residual properties have been assessed by compression after impact tests. A detailed description of damage development, especially the increase of the rear face crack with respect to the impact energy is given by the microscopic observation. The influence of impact damage on the residual strength is described. A loss of 15%–30% in compression resistance was n…

Optimization and analysis of processes with moving materials subjected to fatigue fracture and instability

2013

We study systems of traveling continuum modeling the web as a thin elastic plate of brittle material, traveling between a system of supports at a constant velocity, and subjected to bending, in-plane tension and small initial cracks. We study crack growth under cyclic in-plane tension and transverse buckling of the web analytically. We seek optimal in-plane tension that maximizes a performance vector function consisting of the number of cycles before fracture, the critical velocity and process effectiveness. The present way of applying optimization in the studies of fracture and stability is new and affords an analytical tool for process analysis. peerReviewed

Electromagnetic-thermal analysis of a hybrid switched-reluctance motor

2002

Salkowski curves revisited: A family of curves with constant curvature and non-constant torsion

2009

In the paper [Salkowski, E., 1909. Zur Transformation von Raumkurven, Mathematische Annalen 66 (4), 517-557] published one century ago, a family of curves with constant curvature but non-constant torsion was defined. We characterize them as space curves with constant curvature and whose normal vector makes a constant angle with a fixed line. The relation between these curves and rational curves with double Pythagorean hodograph is studied. A method to construct closed curves, including knotted curves, of constant curvature and continuous torsion using pieces of Salkowski curves is outlined.

Explicit polynomial solutions of fourth order linear elliptic Partial Differential Equations for boundary based smooth surface generation

2011

We present an explicit polynomial solution method for surface generation. In this case the surface in question is characterized by some boundary configuration whereby the resulting surface conforms to a fourth order linear elliptic Partial Differential Equation, the Euler–Lagrange equation of a quadratic functional defined by a norm. In particular, the paper deals with surfaces generated as explicit Bézier polynomial solutions for the chosen Partial Differential Equation. To present the explicit solution methodologies adopted here we divide the Partial Differential Equations into two groups namely the orthogonal and the non-orthogonal cases. In order to demonstrate our methodology we discus…