SOUTHERN JOURNAL OF SCIENCES

Background: MQ-series gas sensors belong to the metal oxide semiconductor (MOS) family of sensors that can sense the presence of many gases. These sensors find their application in gas alarm systems as key components. While necessary sensor circuit output voltage value for alarm point in a stand-alone gas alarm system is desirable, but what exact combination of the sensor circuit parameters is required? Hitherto, the determination of these circuit parameters has not been given much attention in the research community. Aim: the purpose of this work is to explore a structured graphical approach of determination of MQ series gas sensor circuit parameters for a stand-alone gas alarm system that yields desired sensor circuit output voltage value for the alarm point; the main objective of the study was to develop mathematical model equations that relate the: (i) sensor resistance (RS) with the gas concentration (x) and the sensor resistance at standard calibration concentration of the sensor base gas in the clean air (Ro) and (ii) sensor circuit output voltage (VRL), load resistance (RL) and sensor resistance (RS). It is expected from the model equations developed that graphical correlations of the sensor circuits parameters will be generated. Using these graphs for a particular case of an MQ-4 gas sensor under the influence of LPG, the parameters that yield desired sensor circuit output voltage of 2V for 1000 ppm of LPG alarm point will be determined. Methods: Model equations were developed for the sensor dynamics, and based on these model equations, graphs for the determination of required sensor parameters were plotted for a case of MQ-4 gas sensor response to LPG. Results and Discussion: The results yielded optimal values for R_O,R_S and R_L of 20 kΩ, 30 kΩ and 20 kΩ respectively, for alarm settings of 1000 ppm and a desired sensor circuit output voltage of 2 V. Based on determined parameters, the calibration equation for determination of best concentration value for a given value of emulated LPG concentration was developed. Using the method proposed in this study makes the process of determining the MQ-series gas sensor circuit parameters less cumbersome as their value can easily be obtained from the resulting graphs. Conclusions: a structured graphical approach for determination of MQ-series gas sensor circuit parameters for alarm points in a stand-alone gas alarm system showed that using MQ-4 gas sensor and LPG as the target gas, and for a sensor circuit output voltage of 2 V for alarm point at 1000 ppm of LPG, the corresponding value of R_O, R_S and R_L obtained were 20 kΩ, 30 kΩ, and 20 kΩ respectively. Hence, a structured graphical approach is suitable for determining MQ series gas sensor circuit parameters for a stand-alone gas alarm system under the influence of its associated gases.

An indicator of the health of the human body in the state of the oral mucosa. Mechanical and chemical factors constantly influence it. At the first stage of the study, a comparative analysis of the frequency of various forms of traumatic injuries of the oral mucosa was carried out. The distribution of patients into groups was also carried out, depending on the medicinal product used. Then clinical examinations were carried out. After that, the therapy of traumatic erosive and ulcerative lesions of the oral mucosa began. The developed method for treating traumatic lesions of the oral mucosa with medicine based on phytoecdysteroids provides for eliminating the traumatic factor, applying ointment based on phytoecdysteroids to the dried out focus twice a day. The use of phyto-ointment leads to complete repair of traumatic erosive and ulcerative lesions of the oral mucosa on average by the eighth day from the start of treatment; a similar effect with the use of "Solcoseryl dental adhesive paste" is achieved by the tenth day, and the gel "Cholisal Dental" - at a later date, which is confirmed in this study. The most significant positive effect on the level of quality of life associated with the effectiveness of treatment of traumatic erosive and ulcerative lesions of the oral mucosa in comparison with the dental “Solcoseryl dental adhesive paste” and the gel “Cholisal Dental” is exerted by phyto-ointment, where a decrease in the total points was recorded. When conducting routine examinations of patients, it is necessary to pay attention to the oral mucosa damage. Moreover, in treating traumatic injuries of the oral mucosa, it is recommended to use phytoointment, which contains phytoecdysteroids.

Background: The interview was conducted with Professor Paulo Wilton da Luz Câmara, who serves as an associate professor at the University of Vassouras, general coordinator of postgraduate lato sensu programs, and deputy coordinator of the Master's in Environmental Sciences. The Professor has extensive academic and corporate experience. Objectives: The main objectives were to understand the importance of corporate experience in the role of a professor and researcher, discuss the evolution of public entrepreneurship policies in Brazil, understand the role of incubators, explore research on renewable energies in the defense sector, and learn about planned innovations for postgraduate programs. Methods: The interview was conducted in a semi-structured format with open-ended questions. The audio was transcribed for subsequent analysis and content structuring. Results: Corporate experience significantly influences academic performance. There has been relative improvement in public entrepreneurship policies, but the involved bodies lack specific knowledge. Incubators are necessary tools to foster entrepreneurship and innovation. The main challenges in renewable energy research for defense are awareness and organizational policy. Planned innovations for postgraduate programs include connecting education levels, shared management, and an open committee. Discussion: The Professor highlights the importance of practical corporate experience in enriching academic performance, noting advances in entrepreneurship policies while emphasizing the need for more specific knowledge. Incubators are seen as essential to fostering entrepreneurship and innovation. In the field of renewable energy applied to defense, challenges are related to awareness and organizational policy. Conclusion: The interview underscores the relevance of practical corporate experience in enriching academic performance and the need to improve entrepreneurship policies. Incubators are fundamental to fostering entrepreneurship and innovation. Research on renewable energies in defense faces challenges of awareness and organizational policy. Planned innovations for postgraduate programs aim for greater integration and participation.