Journal of Engineering and Thermal Sciences
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Simões Network 2 (SN2): A special model for special needing
Get PDFFunctional Orthopedics appliances must follow strict rules of construction and respect the correct indications, to achieve the proposed goals. The approach must be individualized for each patient according to each needing. Dr Wilma Alexandre Simões created a network of appliances, with no similarity with other appliances created by other authors. Her appliances respect rigid scientific fundamentals and provide for the clinician special tools for solving different types of occlusopathies. Here we present some rules, developed, and scientifically supported by the authors, in order to optimize the use of one of Simões Network called SN2
Bruxism and masticatory pattern: an understudied relationship
Get PDFBruxism as a pathophysiological entity, both day and night bruxism, has been the subject of innumerable investigations. Among the probable causes that have been raised are biochemical alterations in the central and/or peripheral nervous system, which can be seen reflected in an alteration of the rhythmic movements of the masticatory musculature of the stomatognathic system. On the other hand, chewing is recognized as one of the main functions of the stomatognathic system, responsible for maxillofacial growth and determining a rhythm in the movements of the masticatory musculature, depending in turn on a functional demand of the individual, in other words, the type of food consumed and the way to process it in the mouth. Objective: To determine the existence of a relationship between bruxism and the type of masticatory pattern installed in the patient. Methodology: Functional examinations and application of Fonseca questionnaires and bruxism self-report were performed in 27 adult patients, without distinction of sex, who have been diagnosed with possible and probable bruxism. Results: 100 % of the sample of subjects diagnosed with bruxism presented an altered masticatory pattern. Conclusions: The high correlation found in the sample between bruxism and masticatory pattern suggests that it is vital for the success of a bruxism treatment or a DTM to consider the way of processing food, by educating the patient with Masticatory Orientation. Based on the above, it proposes to conduct a study to evaluate the efficiency of a functional treatment for future Bruxism therapies
Treatment of vertical problems with jaw functional orthopedics based on scientific evidence. Part 2: deep bite
Get PDFThe vertical problems of the stomatognathic system that alter the overbite, either by increasing in the deep bite (DB) or decreasing in the anterior open bite (AOB), are among the great challenges of the dentofacial corrections in the treatment and the retention and stability protocols. In this paper the state of art of DB treatment with Jaw Functional Orthopedics (JFO) will be discussed. JFO has a unique diagnostic tool for changes in vertical growth of the face, the Articular Compass, developed by Simões. Individuals with hypodivergence and DB are, usually, difficult to treat and more difficult to stabilize the obtained results. Since 1950-decade Planas advocate that the Equiplan – a metal accessory used in functional orthopedic appliances (FOA) is efficient in deep bite treatment by levelling the occlusal plane. Promising results are found with a P = 0,00, but in aweak evidence study design based on the scientific evidence pyramid. Much of the discussion of incisor intrusion or molar extrusion to treat DB seems to be solved with the use of Equiplan, but it still has no scientific evidence, only clinical evidence. In conclusion Randomized Clinical Trials are needed to investigate the efficiency and Modus Operandi of JFO to treat DB
Bifurcation analysis of fractional duffing system based on improved short memory principle method
Get PDFIn this paper, the dynamic characteristics of fractional Duffing system are analyzed and studied by using the improved short memory principle method. This method has small amount of calculation and high precision, and can effectively improve the problem of large amount of calculation caused by the memory of fractional order. The influence of frequency change on the dynamic performance of the fractional Duffing system is studied using nonlinear dynamic analysis methods, such as Phase Portrait, Poincare Map and Bifurcation Diagram. Moreover, the dynamic behaviour of the fractional Duffing system when the fractional order and excitation amplitude changes are investigated. The analysis shows that when the excitation frequency changes from 0.43 to 1.22, the bifurcation diagram contains four periodic and three chaotic motion regions. Periodic motion windows are found in the three chaotic motion regions. It is confirmed that the frequency and amplitude of the external excitation and the fractional order of damping have a greater impact on system dynamics. Thus, attention shall be paid to the design and analysis of system dynamics
Prediction of operation vibration state of coal mine mechatronics equipment based on data mining
Get PDFIn order to explore the prediction of the operation vibration state of coal mine mechatronics equipment, the author proposes a method based on data mining in response to the problems of large amount of data in the operating state of coal mine electromechanical equipment, low data utilization, and slow speed of single-machine massive data mining, using Map Reduce technology, a dual Map Reduce mining prediction framework is proposed, establish a data mining prediction model for the running state of dual Map Reduce, using MapReduce1 to extract features of monitoring data, use MapReduce2 to predict and analyze feature data. Finally, by building the Hadoop platform, reveal the relationship between Hadoop cluster nodes and parallel processing speed, the efficiency of the data mining prediction framework is verified: Perform an experimental comparative analysis of the single prediction model and the proposed AGB combined prediction model, the prediction accuracy of the AGB combined prediction model is verified
Optimal design and analysis of inner hole positioning mechanism based on MATLAB
Get PDFTaking the copper conductor vertical barrel as the research object, the process flow principle of the packaging system of the copper conductor vertical barrel is described, the mechanism that meets the positioning of the inner hole is proposed. The transmission and kinematics characteristics of the mechanism under different rod sizes are analyzed. The optimal size of the kinematic parameters of the mechanism is solved using the MATLAB optimization toolbox, the size of each member is determined for further determine the specifications and dimensions of the original moving parts to provide a basis for the selection of the original moving parts
Influence of barrier effect on barrier sheet pile wharf
Get PDFThis study aims to investigate the barrier effect of front wall-soil-barrier interactions in barrier sheet pile wharf structures. Berth 32 of the Jingtang Port was taken as the prototype structure, and the prototype observation experiment, centrifugal model test, and numerical calculation analysis were performed to study the influence of the length of the barrier pile, the spacing D between wall piles, and the net spacing L of the barrier pile on the barrier effect. The results show that, to maximize the barrier effect, the ratio N of the pile length of the full barrier pile to the depth of the front wall should be between 1.0 and 1.1. To maximize the barrier effect, the top elevation of the semi-barrier pile should not be excessively low. When the bottom elevation is fixed, the ratio of the length of the semi-barrier pile to the depth of the front wall is approximately N= 0.7. The change in the wall pile spacing D has a considerable impact on the barrier effect. Moreover, D has a logarithmic relationship to the horizontal displacement of the front wall. When D exceeds 3 m, the change in the barrier effect can be ignored. The part of the earth pressure shared by the sea and land sides of the barrier pile to the soil between the barrier pile and the barrier pile has a logarithmic relationship to the net spacing L of the barrier pile. The smaller the L, the better the barrier effect. When L exceeds 2 m, the earth pressure shared by the two parts tends to be average, and the barrier effect can be ignored
Study of torque pulsation control of switched reluctance motor by auto-disturbance rejection control
Get PDFThe switched reluctance motor drives the rotor based on the principle of minimum reluctance, which is structurally simpler, but the doubly salient structure of the stator and rotor leads to severe torque pulsation. This paper briefly introduces the switched reluctance motor and the auto-disturbance rejection controller for suppressing the torque pulsation of the switched reluctance motor. Then, the auto-disturbance rejection controller was simulated in the MATLAB software, and it was compared with the direct torque control strategy. The results showed that the switched reluctance motor installed with the self-reluctance controller reached the set rotational speed faster, with a smoother torque change; when the set speed changed abruptly, it was adjusted to the new rotational speed faster, with a smooth and stable torque change; when the load torque changed abruptly, it was adjusted to the new torque smoother and faster, and the adjustment to the rotational speed was also faster
Simulation analysis on seismic dynamic response of pile supported tunnels in deep backfill area of soil-rock mixture
Get PDFTo reveal the seismic dynamic response of the pile-supported tunnel group in the soil-rock mixture deep backfill region, a three-dimensional finite element model was established based on the engineering conditions of the subway section and three tunnels with close access lines. Subsequently, the seismic dynamic response of the tunnel lining structure was studied. The results show that: Under the action of seismic, the soil-rock mixture stratum presents nonlinear characteristics with shear failure and plastic deformation. In addition, the acceleration and earth pressure of the soil-rock mixture stratum is in a “saturated” state; The seismic dynamic response of the three tunnels influences each other. The bending moments in the X and Y directions of the tunnel lining cross-section are distributed in “X” and inverted “V” shapes, respectively. Meanwhile, the tensile stress and shear stress are distributed in an “X” shape; Under the action of seismic, the main failure form of tunnel lining is tension shear failure, and the most vulnerable position is the left and right arch foot, followed by the left and right arch shoulder; The bending moment of the pile body changes nonlinearly in the height direction. The most significant bending moment value appears at the top 1/5 of the pile length and the junction of different strata. Furthermore, the most significant horizontal displacement of the lining structure occurs at the tunnel vault
Damage localization in beams based on the analysis of modal parameters
Get PDFThis paper presents a two-step method for damage localization in beams by combining natural frequencies and mode shapes. The general locations of the damage are first identified from an indicator developed using relative natural frequency change (RNFC) curves and the values of RNFCs. A curvature-mode-shape-based method is then utilized to determine the specific location of the damage in the second step. The proposed two-step method is verified by detecting damage in a simulated simply-supported beam. The identified damage location agrees well with the actual damage location. A strategy for fast and accurate damage localization based on general localization using natural frequencies and specific localization using mode shapes is the main novelty of the paper