Maintenance, Reliability and Condition Monitoring
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Plagiocephaly and malocclusion
Get PDFThe term plagiocephaly means oblique head. Most skull deformities are a result of intrapartum or utero molding but can be caused by congenital torticollis and after birth due to persistent head position of newborns staying in one head position for a long time and abusive use of strollers, car seats, car seats, swings. Its prevalence is growing fast, in 30 years it passes from 1 in each 300 babies in early nineties to 16 to 48 % in 2020. The aim of this paper is bringing the light to some serious conditions of treatment protocols in individuals with plagiocephaly. The skull deformity causes facial asymmetry that are not treatable by orthopedic or orthodontic intra or extra oral appliances, nor orthognathic surgery. Well, despite the fact that the patient or the tutors have to be notified of the facial asymmetry that persists, functional limitations will be presented. In more than 30 years of clinical experience treating these patients it was never sought the 4 first permanent molars and the 4 canines in the same Angle’s Class. In one side can be seen Class 1, but on the other it will be finding class 2 or class 3, the case reported exemplifies it, and the worst, mastication guidance will have to be very carefully done since, in most cases if it is tried to adjust the inferior and superior dental midline the vertical asymmetry of the occlusal plane (minimum vertical dimension) will worsen. Really there is no unique treatment protocol and it has to be considered case by case. It is time to deepen the knowledge in this area since the prevalence is growing. Based on the case reported, non-treated plagiocephaly can bring serious limitations to malocclusion treatment results. Further studies are necessary to a better understanding of the situation plagiocephaly versus malocclusion
Case report – mesioclusion treated with Bimler C períod of 12 months
Get PDFThis study aims to present a clinical case and assess the efficacy of the Bimler C Elastic Modeler, a functional orthopedic appliance, in the early treatment of a patient diagnosed with mesiocclusion (mandibular prognathism) based on Bimler and McNamara Cephalometrics. Additionally, we aim to delineate the observed positive changes in facial expression during the course of treatment with this functional orthopedic appliance. The female patient, aged six years and nine months, manifested atypical swallowing, respiratory challenges, and allergic conditions such as rhinitis. Comprehensive examination further revealed facial asymmetry and a smile with lip asymmetry. Intra-oral examination exposed a rightward deviation of the mandible, crossbite, open bite, and mesiocclusion. The proposed intervention encompassed the application of the Bimler Elastic Modeler (BEM) functional orthopedic appliance. The documented treatment duration spanned 12 months, with ongoing monitoring every 2 or 3 months. The treatment, utilizing the BEM functional orthopedic appliance, coupled with exercises and adjustments, improved mandibular and tongue posture, enhancing overall chewing balance. The appliance effectively repositioned the mandible to a more balanced position approaching normocclusion, achieving this without causing pain or discomfort and without the necessity for elastic or constant forces. Given the crucial role of facial expression muscles in these activities, a pronounced enhancement in facial harmony was observed. These affirmative outcomes significantly contributed to heightened patient engagement throughout the treatment process and a concomitant enhancement in patient self-esteem, attributable to the documented aesthetic and functional ameliorations
Neuroclusal rehabilitation with planas direct tracks in the treatment of anterior crossbite – literature review
Get PDFPlanas direct tracks (PDTs) are an alternative treatment based on neuro occlusal rehabilitation (NOR) of various occlusal changes in the primary dentition and in the beginning of mixed dentition. Anterior crossbite is a very common malocclusion during this period. The aim of the present work was to report on Planas direct tracks through a literature review based on neuro-occlusal rehabilitation as a therapy for anterior crossbite (ACB). The search for articles was performed in the databases SciELO (Scientific Electronic Library Online), MEDLINE (National Library of Medicine-USA) and Google Scholar. After searching for articles, 12 studies were listed, however, after evaluating the inclusion and exclusion criteria, only 5 articles remained. The articles found proved to be effective in resolving cases with PDTs based on NOR. PDTs were more suitable for the treatment of anterior crossbite in the primary dentition. The inclination of the tracks was variable, both in the anterior and posterior regions, between 20° and 45° degrees. Three case reports in primary dentition observed ACB correction after 30 days with PDT. As a result, two case reports reported that the treatment of ACB was resolved after 45 days with the effects of clockwise rotation of the mandible and its retropositioning. Another effect observed was the uncrossing of the anterior teeth, presenting an uncrossing of the bite and improvements in facial and postural symmetry. The NOR-based PDT for the case reports presented promoted the resolution of ACB malocclusion, promoting the correction of jaw posture, and in turn, improving the facial and postural symmetry of the mandible
Checking the manufacturing of Simões Network 10 – SN10 through surface electromyography (sEMG) – case report study
Get PDFUse of functional orthopedic appliances (FOA) in the treatment of malocclusion and Temporomandibular Disorders (TMD) has been proved to be effective but there is still questions to be answered like the muscular action of the referred appliances. The aim of this study is checking through a proven protocol of surface electromyography (sEMG) to study muscular action of FOA to check to check if it is correctly manufactured. The appliance studied is a Simões Network 10 – SN10 to treat Class II malocclusion of retrognathia. The sEMG was collected 1 patients with class II malocclusion with retrognathia who belong to a 164 volunteers with malocclusion, in two times T1 before installation of the FOA in mouth, T2 15 minutes after the FOA installation in the mouth. sEMG data of bilateral masseter, bilateral temporal and bilateral suprahyoid muscles using conditioner signals module from Lynx Electronics Ltda with 8 channels, model EMG1000; software AqDAnalysis 4,18 from Lynx Electronics Ltda.; Software Lynx BioInspector 1,8r; passive surface electrodes (Ag/AgCl) from Noraxon Dual Electrodes (USA); dischargeable reference electrodes Kendall Meditrace (Ag/AgCl) – Canada were used for the sEMG measurements. Frequency calibration was 2000 Hz, with 2048 sample by channel and time 1,024 seconds, and filters regulation was 20 Hz and 1000 Hz. With the FOA in the mouth all measurements improved with a more simetrical sEMG in T2 in rest and isometric contraction measurements. The protocol used to check the manufacturing of functional orthopedic appliances using surface EMG proved to be a valid tool in this case report study. Further investigations are needed to confirm this protocol and check if the same happens with other types of functional orthopedics appliances
An improved semi-supervised prototype network for few-shot fault diagnosis
Get PDFThe collection of labeled data for transient mechanical faults is limited in practical engineering scenarios. However, the completeness of sample determines quality for feature information, which is extracted by deep learning network. Therefore, to obtain more effective information with limited data, this paper proposes an improved semi-supervised prototype network (ISSPN) that can be used for fault diagnosis. Firstly, a meta-learning strategy is used to divide the sample data. Then, a standard Euclidean distance metric is used to improve the SSPN, which maps the samples to the feature space and generates prototypes. Furthermore, the original prototypes are refined with the help of unlabeled data to produce better prototypes. Finally, the classifier clusters the various faults. The effectiveness of the proposed method is verified through experiments. The experimental results show that the proposed method can do a better job of classifying different faults
1D manipulator with vibration impact drive, based on which it is possible to create orthogonal manipulators and robots of any dimension
Get PDFManipulator of the investigated type may move according to a straight line. It has an advantage in the fact that by choosing geometrical parameters of the manipulator it is possible to achieve its effective operation. This is presented by using analytical and graphical methods. The performed research shows that manipulators with vibration impact drives have some positive qualities. In their structure it is not necessary to include the self-stopping mechanism. In the conservative case of the system static position of equilibrium of the impact pair can be with negative, zero or positive tightening. In the case of zero tightening eigenfrequency and period of the system does not depend on the quantity of motion of impact excitation. In the case of harmonic forced excitation resonant motions take place in the vicinity of the eigenfrequency of the conservative system with zero tightening. Analytical – numerical calculations contribute to the creation of manipulators and robots with vibration impact drives
Modal analysis and optimization design of ultra-high acceleration platform rail frame
Get PDFThe ultra-high acceleration macro and micro motion platform has the advantages of high positioning accuracy and small error, and the key mechanism rail frame of the ultra-high acceleration macro and micro motion platform is optimized based on modal analysis to achieve the performance optimization of the platform. SolidWorks software was used to build the rail frame model, and ANSYS Workbench software was used to carry out modal analysis, topology optimization and response surface optimization, etc., so as to reduce the quality of the rail frame as much as possible under the premise of maintaining the stability of the first-order natural frequency. The results show that the optimization of the response surface meets the expected goal, the first-order natural frequency of the guide rail frame increases by 0.7 %, the mass decreases from 6.165 kg to 5.592 kg, and the change rate is 9.2 %, which achieves the purpose of lightweight
A study into the fluid power control characteristics of a hydrostatic transmission for mobile machinery
Get PDFIn response to improve the quality and level of hydrostatic transmission (HST) products for modern mobile machineries, the closed-loop transfer functions of a HST are established by mathematical modeling, a comprehensive testing equipment is developed employing a proportional relief valve for automatic program loading and fuzzy-PID oil temperature control, the testing equipment is capable of conducting various performance tests for various models of HST integrated pump-motor products, including factory and type tests, especially continuous impact and endurance performance tests under high temperature and high-speed conditions. Comprehensive performance test of the above test sample is carried out using the developed equipment, that the test results agree well with the previous simulation results verifies the correctness of the established theoretical analysis model. The obtained theory and equipment from this work provide theoretical and experimental technical support for improving design and development of high-end fluid components for modern mobile machinery HST
Self-synchronisation of vibration exciters of a biharmonic vibration drive
Get PDFThe paper considers the practical possibility of self-synchronisation of two biharmonic unbalanced vibration exciters mounted on a solid body with plane oscillations. The problem is solved by the method of direct separation of motions. The equations for slow processes of establishing synchronous modes of rotation of the exciters are obtained; expressions for vibration torque; the vibration coupling coefficient and the condition for the existence of an synphase mode of motion. It is shown that the latter condition is relatively “soft”. An expression for the vibration torque is obtained for the case of “stuck” velocity of a biharmonic exciter in the resonance zone of a vibration machine. Recommendations for selecting the parameters of the vibration drive are given. The analytical conclusions are confirmed by computer modelling
Gas parameter characteristics in Reflux Flotation Cell
Get PDFFlotation is a primary method for separating fine particles, and the growing demand for processing these particles has driven recent research efforts towards developing and designing more efficient flotation devices. Among these, the Reflux Flotation Cell (RFC) stands out as an innovative solution specifically tailored for fine particle flotation. Gas parameters are crucial factors influencing flotation and are essential indicators for evaluating flotation equipment. This study primarily investigates the gas characteristics within the RFC, including bubble size, gas holdup, and bubble surface area flux. The experimental results indicate that bubble diameters range from 0.4 to 0.8 mm, gas holdup ranges from 30 % to 50 %, and bubble surface area flux ranges from 120 to 400 s-1. These findings demonstrate that the RFC provides an optimal gas environment, conducive to effective mineral flotation