On an application of node MCU Esp8266 in opening and closing the laboratory door - online practice

This paper presents an application of ESP8266 node MCU in building a networked laboratory door opening and closing system (NLDOC system). The article mentions the function of the ESP8266 node MCU [1-3], and the Arduino application to serve as the basis for the development of an application that connects computers and smartphones [5-6], allowing to control the door latch of the practical labs remotely via Wi-Fi combined with security monitoring through the camera system [4].

The Impact of Rolling Stock Heterogeneity on Tram Stop Dwell Time

The prediction of stop dwell time is a major issue in travel speed modeling, i.e., in the definition of travel time for high-frequency and high-ridership rail public transport. This is due to the numerous influential factors associated with stop dwell time, variable both in space and time, such as passenger flow, vehicle and stop design characteristics, and traffic organization. To investigate the impact of the heterogeneity of tram vehicles on stop dwell time, a survey was conducted regarding the tram network of the City of Zagreb. The dwell time at three consecutive island stops served by three different tram vehicle types was analyzed. The stops are located near the city center, in a separate tram corridor, at the far side of signalized intersections. Dwell time was determined and evaluated through the statistical analysis of observed, measured, and video-recorded data. The results show that at stops with up to 200 passengers per hour, the dwell time is around 15 s. For volumes of 20 passengers or less per tram, the dwell time is mostly affected by the tram door opening mechanism and opening/closing time. As the passenger volumes become higher, the number of doors per vehicle becomes more significant.

Determinants of asthma in Ethiopia: age and sex matched case control study with special reference to household fuel exposure and housing characteristics

Background Asthma is a chronic inflammatory disorder characterized by airway obstruction and hyper-responsiveness. Studies suggest that household fuel exposure and housing characteristics are associated with air way related allergy. But there remains to be a considerable uncertainty about whether that reflects an association with asthma. This study endeavored to bridge the gap by identifying factors associated with asthma, with special reference to household fuel exposure and housing characteristics in selected public hospitals in Addis Ababa, Ethiopia. Methods We conducted a hospital-based matched case-control study. A total of 483 study participants were selected from two Ethiopian referral hospitals using a sequential sampling technique, with 161 cases and 322 controls. Standard questionnaire from the European Community Respiratory Health Survey II (ECRHS II) and the American Thoracic Society Division of Lung Disease (ATS-DLD-78) were used to collect household related data. Conditional logistic regression model was applied to identify the determinants of asthma. Both crude and adjusted odds ratios with 95% confidence interval (CI) were used to identify predictors of asthma. Results The response rate for both cases and controls was 99.17%. The odds of developing asthma was about four times higher among those who used agricultural residues for cooking (AOR: 3.81, 95% CI: 1.05, 13.79)., about five times higher among those who used wood for cooking (AOR: 4.95, 95% CI: 2.1, 11.69), nearly five times higher among those who had family history of asthma (AOR: 4.72, 95% CI: 1.54, 14.45), just over six times higher among those who smoke tobacco (AOR: 6.16, 95% CI: 1.31, 29.09) and over ten times higher among those who do not practice door opening, while cooking (AOR: 10.25, 95% CI: 3.97, 26.49). Conclusion Family history of asthma, tobacco smoking, use of solid fuels including, woods and agricultural residues were associated with development of asthma. To reduce the risk of asthma, people should practice door opening, while cooking, and must avoid using wood and agricultural residues for cooking and should also refrain from tobacco smoking.

SIMULATION OF DOOR MOVEMENT WITH A CLOSING MECHANISM

The work objective is to determine the parameters of the closing mechanism that provide the specified characteristics of the door movement. Research method: computer simulation of the movement of a door with a lock mechanism as a multi-mass dynamic system, taking into account the mechanical characteristics and contact interaction of the lock mechanism. Research results and novelty. Computer dynamic models of a door with a door closer and a door with a spring have been developed. The moments of the door opening force, the closing time of the door, the angular velocity of the door at the time of impact with the frame are considered as the criteria for the quality of the door closing mechanism. Formulas are obtained that determine the permissible values of stiffness and deformation of the door closer spring according to the specified moments of the door opening force. The movement of doors with a door closer and with a spring is compared. The parameters of the closing mechanism providing the specified characteristics of the door movement of the considered example are determined. It is shown that with the same values of the opening force moments, the speed of impact with the frame in the case of the door closer is less than the door with a spring. Conclusions: The developed computer dynamic models of a door with a door closer and a door with a spring make it possible to determine the characteristics of the door movement taking into account the inertial and mechanical characteristics of the door closer and spring mechanisms. The permissible values of stiffness and deformation of the door closer spring can be determined by the specified moments of the door opening force in two positions. It is established that the forces of air resistance and friction in the hinges of the door cannot create the moment of resistance necessary for smooth closing of the door without a strong impact on the frame with a limited closing time. The quality criteria that minimize the closing time and the speed of impact of the door with the frame are contradictory. The choice of optimal parameters of the door closing mechanism is possible if one of the criteria is replaced by a restriction. The developed formulas and computer models are recommended for use in the design of devices that restrict the movement of doors.

Vehicle Door Opening Control Model Based on a Fuzzy Inference System to Prevent Motorcycle–Vehicle Door Crashes

The goal of this research is to develop a fuzzy logic-based vehicle door control system to avoid motorcycle–vehicle door crash accidents. Accidents of this nature usually occur when the driver has parked the car, opens the door getting out of the car and collides with a motorcycle approaching from the rear, causing injury to the motorcyclist. In order to prevent such accidents, the fuzzy logic control system inputs the speed (MS) and safety distance (SD) of the motorcycle approaching from the rear, and then the fuzzy inference unit (FIU) calculates the clear output (Crisp) defuzzification Vehicle Door Opening Model (VDOM) value for the central locking system of the car, which can be used to trigger three modes, namely Danger Mode, Caution Mode and Warning Mode. In this study, the VDOM system is designed to trigger reasonable, reliable and consistent door control under different speeds of motorcycles coming from the rear and will be effectively applied to the door control of semi-automatic cars in the future.

Research on Dynamics Stiffness of Honeycomb Sandwich Structure Door

During the emergency opening of the aircraft door in the air, the door must experience a complex and harsh mechanical environment. In order to ensure the high reliability of the door, it must have sufficient dynamic stiffness. When using finite element software for static engineering analysis, the calculation results often have large deviations due to improper simplification of the motion links in the structure. Aiming at the characteristics of the honeycomb sandwich structure of a class of civil aircraft doors, a combination of topology optimization and dynamic analysis was adopted to take into account the door load and the door opening speed. The results of dynamic calculation show that when the door is opened in the air, the bending deformation during cruise is in compliance with the requirements, and the structural rigidity meets the functional requirements. The research results have important effects on the design and optimization of the stiffness performance of honeycomb sandwich doors.

Temporary Shoring System on Masonry Buildings After an Earthquake

Historical masonry structures that make up the cultural assets of a country constitute the identity of the society to which it belongs. For this reason, it should be protected and should be transferred from generation to generation. Earthquakes are threatening action to masonry structures. The force generated by the ground movement may cause shear cracks in masonry structures that may lead to fragmentation and even collapse of the structure. It is necessary to know the earthquake behaviour of masonry structures to be able to apply appropriate temporary shoring system after a damage caused by earthquake in order to prevent the future damages during aftershocks. Thus, the progress of the damages in the building is prevented and it is ensured to survive until detailed investigation or restoration. However, when the applied temporary shoring system designs were examined, the environmental conditions of the building were not taken into account in any guideline on immediate shoring. In this paper, temporary shoring system for 3 traditional houses of Bey District is designed for possible earthquake damages. This district has many registered civil architectures lined side by side along very narrow streets. Some masonry buildings were changed to reinforced concrete with multiple floors. This study includes the registration status of the buildings, their location, the number of floors to be supported, the heights between floors, the height of the forces that can be brought by the adjacent building elements, the width of the street where the facade to be supported, whether there is a window or door opening in the facade to be supported etc. If there are window or door openings, the distances of the opening to the corner points of the building and the distances between the two openings has to be recorded. According to these determinations, possible damages that may occur in the buildings are defined and a temporary shoring system is designed in accordance with the buildings and the surrounding conditions.

Research on reliable sealing technology of spacecraft rectangular hatch based on boundary control

In view of the large size of the sealing surface of the space large diameter rectangular cabin door, the large number of locking mechanisms and long service life, it is difficult to adjust the multi degree of freedom attitude in the assembly process, the complex assembly and adjustment of the mechanism, the synchronization accuracy is not easy to ensure, the consistency of the multi-point seal compression rate is high, and it is not easy to control. Based on the rotation law of the spatial linkage mechanism, the precise dimension chain control of the hatch is carried out, and the attitude of the multi degree of freedom linkage is adjusted to realize the synchronous compression of multiple compression units of the compression mechanism; Based on the minimum and maximum operating force as the boundary, through the sealing stress simulation, the “boundary control” coupling assembly and adjustment technology is proposed to optimize the sealing structure and realize rapid and efficient assembly. The results show that the vacuum leakage rate is still less than 2.5×10−3 PaL/s after 2000 door opening and closing tests and sealing compression ratio are better than 15%. The long-life test verifies the feasibility and effectiveness of this method, and forms a set of high reliable and long-life sealing assembly and adjustment method of space hatch, which provides technical guidance and reference for the subsequent assembly of similar space hatch mechanisms.

The Potential of Conversion of Sea Wave Energy to Electric Energy: The Performance of Central Sulawesi West Sea using Oscillating Water Column Technology

With seas area of 70% larger than land, Indonesia encourages the potential for marine energy as an alternative to renewable energy. One of the technologies developed to utilize ocean energy is the Oscillating Water Column (OWC). The OWC method can convert ocean wave energy by using an oscillation column directing wave energy through the OWC door opening to generate electricity. This study aims to determine the magnitude of the waves utilized in West Central Sulawesi’s seas region include Alindau beach, Marana beach, and Kaliburu beach. Based on wave forecasting using wind data for five years, the maximum wave height for five years is 0.20 m. Estimated power from the calculation results obtained a rate significant with an efficiency level of 11.97%. Alindau is a potential location to develop wave energy.