Automotive Powertrain Management

Given the diversity of phenomena that occur during operation of automotive powertrain and their strong impact on the environment, this paper presents a unified approach to these problems. This is a complex pattern study, composed of a mathematical model, a simulation done by inserting subroutines in the software package MATLAB 6.5 and a CATIA V5R16 environment modeling. By customizing the model obtained can define it completely stabilized operating modes of propulsion systems and their dynamic, economic and pollution parameters. This provides, even the design phase, definition of additional constructive and functional criteria against the current, to ensure stable and economic operation, in an area as extensive

Two Steps for an Environmental Friendly Propulsion Engine

A logical way to preserve the natural resources and lowering the pollution level is the improving of the thermal engine efficiency in order to reduce the fuel consumption. Considering the weight factor of the spark ignition engine in automotive market, the authors propose a combined solution to improve the performances of this thermal engine. First, in order to improving the combustion efficiency, we are trying to obtain a closer approach to the ideal constant volume combustion cycle, specific to the spark ignition engine, by developing a variable sequential ratio engine. Secondarily, by modifying the architecture of the compression ring, the theoretical model developed allows the determination of a new transversal profile of the compression ring in order to obtain better lubrication conditions, to lower friction ware and increase the mechanical efficiency. This theoretical and experimental study regards the both modification of these parameters in various situations, aiming at the optimization of this environmental friendly propulsion engine

Chin cup therapy for mandibular prognathism

The purpose of this work was to provide a comprehensive description of craniofacial alteration in the Class III patient in response to orthopedic chin cup treatment. Thirty patients with skeletal Class III malocclusion under treatment with the chin cup appliance, averaging 6 years of age at the start of treatment, were followed longitudinally for a 3-year period. This treatment sample was compared cephalometrically with an analogous untreated Class III sample.The following significant craniofacial alterations were noted in the sample that underwent orthopedic chin cup therapy: 1. 1. A retardation of vertical ramus growth.2. 2. A retardation of vertical development in the posterior aspect of the mandibular body.3. 3. A retardation of vertical development in the posterior maxilla.4. 4. A closure of the gonial angle.5. 5. A distal rotation of the mandibular complex.6. 6. A decreased amount of anteroposterior anterior cranial base growth.7. 7. A redirection of the predominantly horizontal mandibular growth pattern to a more vertical direction.8. 8. A reduction of the maxillomandibular malrelationship toward normative values.9. 9. A production of an Angle Class I dental relationship following the establishment of normal maxillomandibular relations.10. 10. A lack of detectable localized effect on the symphyseal region or incisor position as a direct result of chin cup placement and pressure.11. 11. Development of soft-tissue profile changes in harmony with underlying skeletal changes.While all of the listed alterations are important when analyzed separately, they gain increased importance when considered together. With orthopedic chin cup therapy, there is a change in craniofacial pattern leading to the observed resolution of the Angle skeletal Class III malocclusion. This study thus provides strong support for the use of the orthopedic-force chin cup appliance in the clinical management of young patients with skeletal mandibular prognathism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23012/1/0000581.pd

The physiological linkage between molar inclination and dental macrowear pattern

Objectives: Exact symmetry and perfect balance between opposite jaw halves, as well as between antagonistic teeth, is not frequently observed in natural masticatory systems. Research results show that asymmetry in our body, skull, and jaws is often related to genetic, epigenetic, environmental and individual ontogenetic factors. Our study aims to provide evidence for a significant link between masticatory asymmetry and occlusal contact between antagonist teeth by testing the hypothesis that tooth inclination is one of the mechanisms driving distribution of wear in masticatory phases in addition to dietary and cultural habits. Materials and Methods: The present work investigates the relationship between dental macrowear patterns and tooth inclinations on a sample of complete maxillary and mandibular 3D models of dental arches from 19 young and adult Yuendumu Aboriginal individuals. The analysis was carried out on first molars (M1) from all quadrants. Occlusal Fingerprint Analysis was used for the quantification of macrowear patterns, and 2D cross-sectional geometric analysis was carried out to investigate asymmetry in dental arches. Results: The asymmetry is highly variable on both arches, and it is associated with differences in the inclination of upper M1 crowns. Each molar has variable inclination (buccal/lingual) which influence tooth to tooth contact, producing greater or lesser variation in wear pattern. Interindividual variability of morphological variation of the occlusal relationship has to be considered in macrowear analysis. Discussion: Our results suggest that overall asymmetry in the masticatory apparatus in modern humans affects occlusal contact areas between antagonist teeth influencing macrowear and chewing efficiency during ontogeny