Journal of Mechanical Engineering, Automation and Control Systems
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Simulation analysis of force and fatigue life of circular wheel of crawler vehicle
No full textDuring loading and driving, the wheels bear the vertical load from the body mass and the excitation load generated by uneven road surface on the one hand, and bear the driving torque on the other hand. The load-bearing methods of wheels are generally divided into bottom load-bearing and top load-bearing. This paper describes the structural characteristics of the track system of the articulated track vehicle and the interaction relationship between the main components of the track system. Finite element calculation is carried out based on ANSYS software to obtain the stress distribution of each key component under various loading methods. It can be seen from the results that all key components of the track system can meet the strength and rigidity requirements; although there are also areas with large local stress, they are all within the safe range, which is mainly caused by stress concentration. Safe life is obtained through fatigue analysis
Triangular state stress and deformation analysis of deformable tracked wheel
No full textThe Variable Morphology Wheel-Track Mechanism (VMWTM) is an innovative mobile platform design designed to overcome the limitations of traditional track and wheel designs in different terrains and mission requirements. Based on the importance of the crawler wheel in the tracked vehicle, the vehicle transmission shaft transmits the power and torque of the power source to the crawler chassis, so the overall working performance of the vehicle depends to a certain extent on the performance of the crawler wheel. In-depth and detailed research on the structure of the track wheel module is an important issue in the current vehicle design and manufacturing work. Based on the relevant theories and technologies of the finite element method, this paper conducts in-depth analysis and design. Taking the whole crawler wheel mechanism and the key components as the analysis object, the basic research method is the finite element method. The working principle of the crawler wheel is analyzed, and the load calculation, stress characteristics and structural strength of the key components of the triangular crawler wheel module are deeply explored according to the technical requirements and actual working conditions
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
A precise localization algorithm for unmanned aerial vehicles integrating visual-internal odometry and cartographer
Get PDFAccurate positioning in space is an important foundation for ensuring the stability of autonomous flight and successful mapping and navigation of unmanned aerial vehicles (UAVs). At present, the SLAM algorithm based on the Cartographer algorithm for real-time positioning and mapping is widely used in fields such as robot navigation and autonomous driving. However, in the context of UAV applications, this algorithm has a high dependence on the amount of point cloud information in the surrounding environment, and cannot achieve precise positioning in open spaces with insufficient lighting and fewer feature points, resulting in significant mapping errors. In order to solve the problem of low positioning estimation accuracy in the Cartographer algorithm in above environment, this paper proposes a precise positioning algorithm for UAVs that integrates VIO and Cartographer. This algorithm can continuously output more accurate position estimation information during UAV flight, compensating for the problem of inaccurate position estimation caused by partial feature loss or coordinate system drift in point clouds. In addition, this algorithm ensures navigation obstacle avoidance in narrow spaces by improving positioning accuracy and mapping accuracy, making it more applicable in the field of UAVs. Finally, the effectiveness of the proposed positioning algorithm was verified through experimental analysis of the Cartographer dataset and practical testing of UAVs in real scenarios
Effect of aging process on precipitated phase and properties of mechanical extruded aluminum alloy
Get PDFAs the industrial sector develops, the performance requirements for aluminum alloys are also constantly improving. The study explores how aging and rolling treatment affect aluminum alloys' precipitates and mechanical properties by controlling the parameters of aging process and rolling deformation variables. 7N01 aluminum alloy was selected as the experimental object, and the samples were treated with non-aging, natural aging, artificial aging, and rolling deformation. How aging processes and rolling deforming affected alloys’ mechanical properties was evaluated through performance testing (mechanical and tensile testing) and material fiber characterization methods (advanced electronic instruments). These results confirmed that the combination of three aging pre-treatments + R20 % + 120 °C re-aging could significantly improve the hardness of aluminum alloys and maintain high ductility. As the deformation decreased, the time for the sample to reach the hardness peak was shorter and the hardness was higher. The 20 % deformation sample’s strength was better than the 80 % deformation sample’s. This confirmed that appropriate aging process and deformation combinations could improve the strength and hardness of aluminum alloys. These results have certain guiding significance for optimizing the aging process of mechanical extruded aluminum alloys and provide reference for the study of related alloy properties
Advances of 3D printing in oral oncology: personalized technologies for patients – a narrative review
Get PDFThis study presents a narrative review of the literature that focuses on the substantial relevance and practical application of additive manufacturing and 3D printing in the context of oncology patients in the dental field. To address innovative technologies for diagnosis and treatment, this review underscores the progressive role of 3D printing in the creation of customized models for rehabilitation, surgical planning, prosthetics, examinations, and even tissue engineering. We analyzed five articles focused on the following categories: applications, benefits, and challenges associated with additive manufacturing; 3D printing; head and neck cancer; as well as assistive technology in the context of improving the effectiveness of treatments for people with this type of neoplasm. Oropharyngeal squamous cell carcinoma stood out as the most cited neoplasm for the use of 3D printing. 3D printing has played a significant role in transforming oral cancer treatment by providing customized solutions and enhancing outcomes: custom implants and prosthetics, patient-specific radiotherapy accessories, dose modulation devices, and improved preoperative planning. Additionally, 3D printing enables the production of complex medical devices in a single process, reducing steps and potentially costs. This also opens doors to creating more affordable solutions and extends the reach of personalized treatment to a greater number of patients. Continuous advancements in research and development of additive manufacturing and 3D printing technologies demonstrate significant potential for optimizing treatments and improving outcomes for patients with head and neck cancer
Natural resources can help reducing cardiovascular risk: randomized controlled study
Get PDFCardiovascular diseases are the leading cause of death globally accounting for 32 % of all global deaths. Addressing modifiable risk factors, including hypertension and stress, remains paramount in the prevention of CVD. This study aimed to assess the impact of the balneotherapy on blood pressure, heart rate, electrocardiogram parameters, utilization of antihypertensive medications, and stress levels. Methodology. Multicenter randomized controlled single-blind parallel group trial was made in 6 Lithuania resort centers. 373 participants with the stress level > 3 (10, VAS) randomly divided into 6 groups in two clusters for receiving a 6- or 11-day complex treatment using natural resources – mineral waters, peloids, salt, nature therapy; follow-up period was 6 months. The BP, HR, ECG, stress level and other parameters were analyzed in 131 participants who passed a full course of investigation. Results. The significant reduction of systolic blood pressure after treatment (7.8 mmHg) and during 6 months (7.3 mmHg) together with diastolic 5.5 after 6 month and heart rate (4 b/min) was achieved in 11-day ambulatory balneotherapy group. Increase in the activity of the parasympathetic nervous system was observed, which is reflected by an increase in the duration of the ECG indicators. The stress level decreased by up to 43%, and stress management improved by up to 41% following inpatient treatment. Conclusion. Therapy using natural resources could stand for additional cardiovascular disease prevention and management method in integrative therapy
Reading Gokturkish text with the Yolo object detection algorithm
Get PDFThis study has important scientific, cultural and economic contributions. From a scientific point of view, the decipherment of Gokturkish texts is of critical importance for research on Turkish culture, history and language. This study will enable historians and researchers to analyze these documents more quickly and effectively. Culturally, the reading of Gokturkish texts will help us gain a deeper understanding of Turkish culture and history. For linguists and cultural researchers, understanding these texts can offer new perspectives on the richness and cultural heritage of the past. From an economic point of view, this thesis argues that computer-assisted reading technology can contribute to a faster and more efficient reading and understanding of Gokturkish texts, making it easier to analyze the documents. This in turn frees up more time and resources for researchers and cultural experts, allowing them to focus on future work
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
The impact of occlusal plane rehabilitation on the face of a patient with traumatic peripheral facial paralysis by Timpanic jugular tumor – case report
Get PDFThe musculature of the face is innervated by cranial nerves, each with a motor, sensory and/or both function. The Facial nerve (FN) is responsible for the motor innervation of the muscles of the face. Some branches of the trigeminal nerve are responsible for the sensory part of the facial muscles and other branches act on the motor part of the chewing muscles. Traumatic Facial Paralysis (TFP) is the one where there was section or traction or compression or ischemia of the FN, in surgery for tumor resection or trauma in general. In this case occurs the nerve’s section in one surgery. Facial Paralysis (FP) can be evaluated subjectively through the House and Brackmann classification scale (HB) [1]. It is considered a chronic FP when it persists for a period longer than 6 months and leaves sequelae, such as synkinesis, contractures and lack of complete innervation of some nerve branches. Some patients who evolve with chronic FP may also evolve with alteration of the occlusal plane. The occlusal plane is the meeting point between the antagonist teeth, plane that is in the final stop of the masticatory cycle. The rehabilitation of this plan is performed according to the needs of each patient, in this case was made through implant prostheses