Scientific Research and Essays

  • Design and Implementation of an Eye-Controlled Self-Driving Wheelchair

    The purpose of this paper is to develop a mechatronic system, the Eye-Controlled Self-Driving Wheelchair (ECSDW), that can help paralyzed, handicapped or any peoples who have an injury in their upper part of the body to be easily and successfully navigate autonomously from one position to another within indoor environments while avoiding obstacles dynamically. This research aims to present a unique approach which can be achieved inexpensively and has the eye-controlled additional property with robust autonomous assistive navigation when compared to a commercial existing wheelchair. The proposed ECSDW system platform is capable of localization and mapping, as well as robust obstacle avoidance, using only a commodity RGB-D sensor and wheel odometry. The development of the proposed ECSDW system was firstly carried by simulating the navigation of the wheelchair using Gazebo and Rviz running in ROS. Secondly, the hardware was assembled and built and the ROS nodes were implemented using Python programming language. Finally, the GUI was designed and implemented for a custom map so that, the disabled user can stare to a specific location using the GUI, with the help of eye-tracker sensor, which accepts directed eye signals and direct the wheelchair to navigate to the desired position autonomously.

  • Effects of Radiation and Heat Generation on Magnetohydrodynamic Free Convection Flow along a Horizontal Cylinder with Conduction

    In this paper, the flow characteristics and the heat transfer process due to natural convection and conduction along a horizontal cylinder in presence of radiation, magnetic and heat generation effects are examined. The effects of radiation, magnetic and heat generation on electrically conducting fluid in natural convective flow along a non-linear system of partial differential equations is reduced to local non-similar horizontal cylinder with conduction have been studied in this paper. The governing boundary layer equations for this phenomenon are transformed into a non-dimensional form and the resulting partial differential forms by adopting appropriate suitable transformations. The transformed boundary layer equations are then solved numerically by using the implicit finite difference method. Numerical results of the velocity profiles and temperature distribution, coefficient of local skin friction and local rate of heat transfer distribution for the Prandtl number, radiation, magnetic and heat generation parameters are presented graphically. Detailed discussion is given for the effects of the aforementioned parameters. Significant effect is found in heat transfer distribution for Prandtl number and radiation parameter. The thermal boundary layer thickness of Prandtl number is clearer than radiation parameter. Important effect is found in heat transfer distribution in Heat Generation effect. An excellent graph is found in magnetic effect for heat transfer profile, which is as like as a spiral situation.

  • Research status and development direction of controlling factors of graphite mineralization in coal measures

    Coal-measure graphite mineralization control is affected by many factors. In order to explore the ore-forming control factors and influence mechanism, the paper comprehensively analyzes the influence and mechanism of each factor from five aspects of coal rock composition, coal grade, temperature, pressure and mineralizer, combined with geological examples. The results show that in the process of graphite mineralization in coal measures, the components of coal and rock have the ability of graphitization, but the higher the degree of metamorphism of coal as carbon source, the higher the degree of graphitization of products, the higher the ore-forming temperature, and the higher the degree of graphitization. The development of tectonic movement promotes the graphitization, but the degree of graphitization is different and complicated due to the stress dissipation. Different minerals in coal have different effects on graphite mineralization in coal measures, and its mechanism needs to be further explored. Finally, it is pointed out that the research direction of coal series graphite lies in the different graphitization mechanism of the same rank coal and the different influence mechanism of different minerals in coal.

  • Analysis of Solvent Effect on Formation Constants and Speciation of Cobalt(II), Copper(II) and Lead(II) Complexes of L-Methionine and Uracil

    The analysis of coordination of chelating agents to metal ions in the formation of complexes under different experimental conditions provide information on the effects of the conditions on the extent of the coordination of the ligands to the metal ions for potential applications in bioinorganic and environmental Inorganic Chemistry. The effect of solvent on the coordination of L-methionine (primary ligand) and uracil (secondary ligand) to Co(II), Cu(II) and Pb(II) ions in the formation of binary and ternary complexes have been potentiometrically investigated in water and 40% (v/v) ethanol- water media at 27 °C and ionic strength of 0.02 mol dm–3was maintained by using NaNO3. The proton-ligand stability constants and formation constants of the binary and ternary systems were established under the experimental conditions. The formation constants of the ternary complexes were numerically compared with the corresponding binary complexes in terms of Δ log K and percentage relative stabilization (%RS). Speciation of the metal ions, binary and ternary complexes as a function of pH in the solutions was investigated by using HYSS program. The ligands were observed to form more stable ternary complexes than binary complexes. The proton-ligand stability constants the ligands and the formation constants of the metal complexes were found to be higher in 40% (v/v) ethanol-water than water. The distribution of the species revealed a decrease in the metal ion concentrations with increase in the concentrations of the binary and ternary as pH increased. The chelating agents interacted strongly with the metal ions and showed different selectivity towards the metals ions. These properties can be exploited in combating metal poisoning, separating the metals and expounding the bioinorganic chemistry of the metal ions and the ligands.

  • BURNOUT SYNDROME AMONG MEDICAL STUDENTS: AN INTEGRATIVE REVIEW

    Introduction: Burnout Syndrome is conceptualized as a result of chronic stress in the workplace, characterized as a psychological syndrome composed of emotional exhaustion, depersonalization and reduced personal fulfillment. The prevalence of this syndrome in medical students is quite expressive, and the more the student is exposed to the academic cycle, the greater the risk of developing an anxiety disorder, especially Burnout Syndrome. Objectives: To analyze in the literature the correlation between Anxiety Disorders, Burnout Syndrome and Medical Students. Methodology: The research took place in the CAPES, PubMed and VHL Regional Portal. The terms “burnout”, “anxiety disorders” and “medical students” were considered as descriptors. Articles published between 2014 and 2019 were included. Results: Of the 69 articles found, only six were included in the review. Evidence was found that there is an association relationship between medical study and student mental exhaustion. It was also relating the time of exposure to the course with a higher prevalence of mental disorders. Relaxation techniques have shown a decline in Burnout’s cognitive and emotional stress and anxiety. Conclusion: Burnout Syndrome is a reality among medical students. However, despite the importance of the theme, the literature on this correlation is incipient. There is a need for further investigations into strategies that aim to reduce the incidence, and consequently the prevalence of this syndrome, favoring the mental health of college students and the training of good health professionals.

  • Maintenance of Bullet Train Based on Mathematical Planning and Workshop Scheduling

    Nowadays, bullet train service stations often suffer from the phenomenon of low operating efficiency due to the unreasonable arrangement of bullet trains that stay in service stations for too long. In order to solve this problem, based on the information of bullet train arrival in two periods of a bullet train service station, this paper comprehensively considered the input source, queuing rules and overhaul intensity of the train service system, determined the objective function and multiple constraint conditions, and established the 0-1 programming model and Uncorrelated Parallel Machine Optimization Model. The model established in this paper can relieve the load pressure of bullet train service station to a great extent, improve the operation efficiency of the service station under the condition of ensuring the maintenance quality of bullet train, and provide theoretical basis for realizing the shortest maintenance time of bullet train service station.

  • ABUSIVE USE OF DRUGS CONTROLLED BY THE USERS OF FAMILY HEALTH STRATEGY THE USERS OF THE IPAUMIRIM FAMILY HEALTH STRATEGY – CEARÁ

    Introduction Benzodiazepines (BZD) are drugs that act directly on the central nervous system, altering cognitive and psychomotor aspects. In Brazil, it is the third class of most prescribed drugs, being used by approximately 4% of the population. The restricted, rational and short-term use of benzodiazepines is not observed on a large scale by professionals who attend the Ipaumirim Family Health Strategy, due to the high number of people who just want the revenue renewal. General Objective: To develop an action plan to promote the reduction of drug abuse controlled by users of the Ipaumirim Family Health Strategy – CE. Methodology: This is an intervention project that consists of an action proposal to face a real problem. The interventions were performed at the Basic Health Unit of Ipaumirim – CE, from June 18 to August 16, 2018 with evaluation every three months, with 36 users. Identification was performed through medical records, interviews in routine consultations. Results: the lack of information from users was clear, resulting in changes in actions involving primary care to alternative treatments such as physical activity, food reeducation and psychotherapy, stimulating actions such as the booklet, an organizational basis, since it does not have the horus system. Conclusion: the study effectively allowed the development of a new health promotion strategy.

  • Experimental Study on the Performance of on-site Mixed Emulsion Explosives and Rock Impedance Matching

    The proportion of on-site mixed emulsion explosives in mining is getting higher and higher, in order to better use the explosive performance of mixed explosives to improve energy utilization. Based on the wave impedance theory, the wave impedance of mixed explosives is changed to make rocks The wave impedances are matched to achieve the purpose of improving the blasting effect and reducing the bulk rate. After field test, increasing the sensitizer content within a certain range is beneficial to the improvement of explosive performance. When the explosive sensitizer content is 1.15%, the best matching coefficient of mixed explosive and rock impedance is 2.51, the rock after blasting is large. The block rate is reduced and the rock crushing effect is better. After this matching test, it is shown that it is feasible to improve the blasting performance by adjusting the explosive performance of the explosive by the optimal wave impedance coefficient according to the hardness of the rock, which can provide reference for the peers.

  • Numerical simulation of propeller jet field based on Star-ccm+

    During the ship’s voyage, the propeller jet affects the movement of silt at the bottom of the bed. To research the influence of the bottom boundary on the propeller jet field, this paper takes the standard propeller DTRC4119 propeller as the research object and uses the CFD software Star-ccm+ to carry out a numerical simulation of the propeller jet under uniform flow. The flow velocity distribution of the jet under four operating conditions is mainly analyzed, including the axial velocity, tangential velocity and radial velocity of the jet. The results show that the distance between the propeller and the boundary does not affect the magnitude and distribution of the velocity on the initial plane but affects the shape of the axial velocity and the velocity on the central axis in the development zone; The closer to the bottom boundary, the greater the disturbance of tangential velocity and radial velocity, the peak value of tangential velocity will be affected and changed from central symmetry of velocity to unanimous trend earlier. The radial velocity contributes less to the overall velocity and can be ignored

  • Development of a workpiece transfer machine based on a gas-electric hybrid system

    To solve the problem of transferring the workpiece to the next process, design a gas-electric hybrid workpiece transfer machine. The mechanical structure of workpiece transfer in automatic production line is discussed. The transfer of workpiece can be realized by pulse motor, pneumatic system is used to clamp and lift the workpiece,and design this system, analyze the principle of pneumatic system and design the PLC circuit. The results show that the designed device has the characteristics of simple structure, operability and practicability.