Methodic for evaluating the performance of a continuous welded track according to the criterion of compliance of the actual rail fastening temperature with the standardized value

Problem of safety evaluation of continuous welded track operation is considered. A comparative analysis of the current assessment methods is carried out and a method is proposed for identifying dangerous track sections according to the criterion of compliance of the actual rail fastening temperature with the standardized one. Under the actual fxing temperature in the article, the temperature of the rail is taken at which, as a result of its thermal expansion or contraction, a zero value of the longitudinal force is formed in it. A method is presented for calculating the actual temperature of rail fastening using the dependence of the natural frequency of rail vibrations on the applied longitudinal force, which was obtained by the computational method using the fnite element model of the track section created by the authors by means of modal calculations for various values of the longitudinal force applied to the rail. Its verifcation was carried out using experimental data obtained as a result of testing at a specialized stand. The method of tests carried out on the stand and section of the continuous track of the Ozerskaya branch of the Moscow Railway is described, which consists in determining the natural frequency of the first mode of rail vibration at different values of the longitudinal force, and in the case of field tests at different values of the rail temperature. The calculation of the actual temperature of rail fastening is given on the example of a section of a continuous-welded track of the Ozerskaya branch of the Moscow railway. It was found that the temperature of rail fastening on the investigated section corresponds to the normative for the given region.

Correlation analysis of Land Surface Temperature (LST) measurement using DJI Mavic Enterprise Dual Thermal and Landsat 8 Satellite Imagery (case study: Surabaya City)

Landsat 8 Satellite Imagery (Landsat Data Continuity Mission, LDCM) is a satellite product made by Orbital Science Corporation, which launched with The Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) instruments as the latest features. One of the Thermal Infrared Sensor (TIRS) instruments is called Band 10, that provide temperature information on the earth’s surface. As many research conduct the temperature comparison between satellite imagery analysis and land cover temperature has been come with positive correlation for both of the variable. As to prove the temperature relationship, it is necessary to validate the actual temperature values on the earth’s surface by conduct the temperature survey in the area using the temperature measurement tools. One of the tools is DJI Mavic Enterprise Dual Thermal camera as the camera that capable to take samples data of particular objects categories that included urban areas, waters, vegetation, open land, settlements, and industrial factories. Using the satellite imagery’s temperature data and the land cover temperature data survey, comparing and accuration assessment are needed to see how close the value of both variable. The data processing carried out that both of the data have a positive correlation as the relationship, which have a Pearson correlation value of 0.892 and sig. (2-tailed) at the number 0.000000068. This correlation value showed that the relationship between both data is acceptable as the both data can represent each other to conduct any research. However, as the satellite imagery contains 29,85% of cloud cover, the temperature obtained lower in the Landsat 8 satellite image rather than the actual temperature on the earth’s surface.

Feedback Analysis and Prevention & Control Strategy of the Real Causes of the Gallery Cracks in Super-High Arch Dam

Gallery cracks occur commonly in concrete dams, but their cracking mechanism has yet to be effectively revealed. In this paper, the actual temperature, stress change history and cracking process of a gallery area were uncovered, based on the safety monitoring data of cracks in a super-high arch dam. In addition, the basic development and change laws, as well as the corresponding cracking mechanism, were analyzed, and the real causes and influential factors of cracks at the site were revealed, which will provide a reference for the prevention of cracks in similar projects in the future.

Establishment and Verification of a Thermal Calculation Model Considering Internal Heat Transfer of Accumulated Water in Permafrost Regions

Water accumulation in permafrost regions causes a heavy thermal impact on the frozen layer, thereby leading to its degeneration. First, based on the real heat transfer process, this study proposes relevant hypotheses and governing equations for heat calculation models involving completely melted water, ice-bearing water, water–soil interface, and soil under water. The models consider the water surface as a thermal boundary on account of the natural buoyancy convection mechanism in water and the phase transition process. Second, this study verifies the accuracy of the calculation models regarding the measured water and permafrost temperatures. The four seasonal vertical temperature changes in the water according to this model are found to be consistent with the actual temperature-change trend, and the permafrost temperature under water is also consistent with the actual temperature field. This study thus provides theoretical support for the thermal impact analysis of water in permafrost regions.

Temperature coverage simulation of horizontal cylinder type coffee roasting machine

This study aims to simulate the temperature distribution of coffee roasting machines and study the profile of coffee beans roasted using a horizontal cylinder-type roaster. The coffee used in this study is arabica. The simulation method for the temperature estimation in the coffee roasting process uses the Solidworks Flow Simulation 2016 software, while the actual temperature measurement using a thermocouple is simulated with the Surfer software version 16. Furthermore, each stage of the coffee roasting process has been carried out, including the weight of the material, the roasting temperature, and the bulk density. The final step is to observe the profile of the roasted coffee beans at every minute of treatment. The study results indicate a difference between the approximate temperature simulation (top 176.85°C, bottom 191.97°C) and the actual temperature measured results (upper 214°C, bottom 220°C). The weight of the material (coffee green bean), the roasting temperature, and the bulk density during the test experienced regular movements from the beginning to the end of the treatment. The profile of roasted coffee beans shows a darker color movement along with the longer roasting time used. The profile of the roasted coffee beans will be beneficial in determining at which level of roasting you want (light, medium, medium-dark, dark).

Design and Implementation of Multiband Noncontact Temperature-Measuring Microwave Radiometer

In this paper, a multiband noncontact temperature-measuring microwave radiometer system is developed. The system can passively receive the microwave signal of the core temperature field of the human body without removing the clothes of the measured person. In order to accurately measure the actual temperature of multilayer tissue in human core temperature field, four frequency bands of 4–6 GHz, 8–12 GHz, 12–16 GHz, and 14–18 GHz were selected for multifrequency design according to the internal tissue depth model of human body and the relationship between skin depth and electromagnetic frequency. Used to measure the actual temperature of human epidermis, dermis, and subcutaneous tissue, a small and highly directional multiband angular horn antenna was designed for the radiometer front end. After the error analysis of the full-power microwave radiometer, a novel hardware architecture of the microwave interferometric temperature-measuring radiometer is proposed, and it is proven that the novel interferometric microwave radiometer has less error uncertainty through theoretical deduction. The experimental results show that the maximum detection sensitivity of the novel interferometric microwave temperature-measuring radiometer is 215 mV/dBm, and the temperature sensitivity is 0.047 K/mV. Compared with the scheme of the full-power radiometer, the detection sensitivity is increased 7.45-fold, and the temperature sensitivity is increased 13.89-fold.

Numerical Integration of Weight Loss Curves for Kinetic Analysis

Research abounds in the literature on kinetic analyses using thermogravimetric (TG) runs. Many of these studies use approximations of integral or derivative forms of the kinetic law and all of them use programmed temperatures. In the present work, a numerical integration procedure was discussed and applied to different examples. We focused on materials presenting a single decomposition curve as well as other materials with more complex processes. Different examples were explored, and the methodology was applied to a number of wastes such as coffee husks, polystyrene and polyethylene. In all cases, the actual temperature measured by thermocouples close to the sample is used, and several runs are fitted using the same kinetic parameters, giving robustness to the results.

Numerical Integration of Weight Loss Curves for Kinetic Analysis

Research abounds in the literature on kinetic analyses using thermogravimetric (TG) runs. Many of these studies use approximations of integral or derivative forms of the kinetic law and all of them use programmed temperature, not the actual temperature measured by thermocouples close to the sample. In addition, it is common to conduct a single run in order to perform the calculation. Nevertheless, many authors consider that numerical methods should be used to analyse the kinetics of decomposition. In such cases, the actual temperature is used and, generally, several runs are fitted using the same kinetic parameters, giving robustness to the results. In the present work, a numerical integration procedure was discussed and applied to different examples. We focused on materials presenting a single decomposition curve as well as other materials with more complex processes. Different examples were explored, and the methodology was applied to a number of wastes such as coffee husks, polystyrene and polyethylene.