Gear drives are widely used in various fields and applications due to their properties and capacity. Their versatility, durability, and ability to transmit high torques as well as precision and ...reliability make them extremely useful in many fields of technology. They are widely used in industrial and energy machinery, vehicle drive systems, aerospace, medical devices, and many other areas. Gears can be manufactured using many technologies. This work focuses mainly on machining with particular emphasis on high-performance new technologies. The process of mathematical modeling of the gear and the machined profile is strongly related to CNC machining technologies. A robust correlation of systems supporting the design and modeling of sliding gears needed for the manufacturing process is presented in the article. It is very important to properly assess gears with correct manufacturing in accordance with a specific standard. The article presents an analysis of available methods for controlling gears using coordinate measurement techniques. Gear machining methods were assessed in terms of the technologies used as well as their productivity and manufacturing tolerance.
In recent decades, the background level of electromagnetic fields (EMFs) has increased extremely. One of the decisive factors influencing this increase is the increase in the quality, volume, and ...speed of voice and data services of mobile operators. This paper deals with the protection of the internal environment from the negative effects of EMFs through elements made of metal materials that absorb this radiation. For the purposes of this research, a series of measurements were carried out on individual days of the week and hours during the day. The results of the measurements were evaluated by the ANOVA method. The aim was to obtain a summary overview of the effects of electromagnetic fields and propose measures for their elimination in the interior. Therefore, measurements of electromagnetic fields were also carried out using shielding elements made of various metal materials, and a comparison of their shielding efficiency was subsequently made. Applications of shading blinds with the highest shading efficiency were recommended to increase safety, protect people's health from its effects, and prevent electromagnetic fields.
In modern society, humans spend most of their time in the indoor environment (home, work, school...). This indoor lifestyle constantly poses challenges to our physical and mental health by affecting ...our hormone levels and circadian rhythm. This article deals with the possible connection between human and working environment factors and the emergence of health problems in connection with work. Using statistical methods, the dependence between the six characteristics (age, length of employment, visual demand of the work task, satisfaction with lighting conditions, and shift work) and occurrence of health-related problems and discomfort (i.e., eye discomfort, headache, eye fatigue, and seasonal affective disorder symptoms) was examined. The paper also deals with the evaluation of lighting conditions in the workshop using the lighting design software DIALux evo 9.2. Using this software, two lighting variants were modeled. The first simulated variant included lighting parameters according to the currently used luminaries and the second variant contained more efficient LED luminaries.
This paper focuses on evaluating lighting conditions in a university classroom used for day and evening classes. The evaluation was made with regard to the legislation requirements for evening ...classes and adult education. The practical part of this paper consists of illumination measuring and simulation. A RadioLux 111 luxmeter was used to measure the illumination during the absence of daylight, which often occurs, especially in winter during the later hours. The simulation was performed in the DIALux EVO 10.1 and ReluxDesktop lighting design software. In both software, a 3D model of the classroom was created to represent its actual state. The results of the measurement and both simulations were compared with each other and with the requirements of the legislation. The requirements for evening classes have not been met in all three cases; therefore, the lighting simulation tools were used to improve the lighting system design concerning its energy efficiency and costs. This paper points out the benefits of using freely available computer software in the process of the calculation and improvement of lighting systems.
During the process of designing and implementing a working environment, there is a need to guarantee adequate conditions for future workers' health and well-being. This article addresses the ...classification of employees characterized by several basic input variables (gender, age, class of work). The investigated variable was the health of employees. This article aims to create a prediction classification model using the classification tree, which can be used to classify new cases into appropriate classes as accurately as possible. Objective measurements of microclimatic parameters were performed by the Testo 435 instrument. The subjective evaluation was performed by a questionnaire survey formed from the training group of 80 respondents and independently verified by the test group of 80 more respondents. The result confusion matrix shows that the number of correctly classified respondents was 69 from a total of 80 respondents. The overall accuracy was A C = 0.863 , which means that the likelihood that respondents are properly classified in the correct health class is 86.3%. Based on the model obtained using the classification tree, we can classify respondents into the relevant class for their state of health. The respondent is classified into the class of work for which particular health and working conditions are most likely.
The continuous development of production processes is currently observed in the fourth industrial revolution, where the key place is the digital transformation of production is known as Industry 4.0. ...The main technologies in the context of Industry 4.0 consist Cyber-Physical Systems (CPS) and Internet of Things (IoT), which create the capabili-ties needed for smart factories. Implementation of CPS solutions result in new possibilities creation – mainly in areas such as remote diagnosis, remote services, remote control, condition monitoring, etc. In this paper, authors indicated the im-portance of Cyber-Physical Systems in the process of the Industry 4.0 and the Smart Manufacturing development. Firstly, the basic information about Cyber-Physical Production Systems were outlined. Then, the alternative definitions and different authors view of the problem were discussed. Secondly, the conceptual model of Cybernetic Physical Production System was presented. Moreover, the case study of proposed solution implementation in the real manufacturing process was presented. The key stage of the verification concerned the obtained data analysis and results discussion.
Currently, there are various complex models that are used to predict the thermal load, or thermal comfort of the employee with different scales for evaluating the feeling of warmth or of cold, with ...the help of which it is possible not only to speed up the evaluation of the thermal load but also to make it more precise. With the help of thermal manikins, it is possible to simulate human reactions to heat and humidity conditions. The article deals with the possibilities of using thermal manikins as a useful aid in measuring heat exchange between the environment and the human body, testing thermal stress, etc. These tools will then be available for use by the industry to develop more efficient thermal comfort systems.
Traditionally EMSs are implemented across all operations at a facility simultaneously. This way of implementation works well for industry and smaller businesses and offices where operations are ...easily delineated and there is a simple chain of command structure in place. The University is able to implement the EMS strategy similarly. Environmental Management System is an integrated organized set of policies and procedures under which the University can remain compliant with applicable environmental regulations, and in addition, manage and lessen our impacts on the environment, thereby improving the University's overall environmental performance. The University's EMS will require continual evaluation of the University's activities to ensure the University is doing as much as possible to reduce its impact on the environment and to remain environmentally compliant. This paper describes present situation and approach of universities to implementation of EMSs in Slovakia and into university management in abroad. The main principles and key requirements of the organisation management in accordance with the sustainable development are not only safety and quality managing of all activities in organisation in both manufacturing and services (education) but also environmental appropriate access.
The in vitro cytotoxicity of both the multiwalled carbon nanotubes (MWCNT) in suspension with culture medium and the tetracalcium phosphate/monetite cement with addition of 0.8 wt% of MWCNTs on ...fibroblasts and osteoblasts were studied. The cytotoxicity was evaluated by MTS test (formazan) and live/dead staining. No cytotoxicity of MWCNT extract was measured contrary to about 60% reduction in proliferation of fibroblasts in MWCNT suspension as compared with negative control. The several contact cytotoxicity of MWCNT composite cement surfaces on seeded cells was demonstrated by MTS test and live/dead staining of damaged fibroblasts and dead osteoblasts after 72 h of culture. The detailed microstructure analysis showed a significant refinement of the surface texture due to the formation of thin needle-like hydroxyapatite particles on MWCNTs and this effect could be responsible for cytotoxicity of composites.
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