Browse Topic: Humidity
Whether it’s the meeting room of an office building, the exhibition room of a museum or the waiting area of a government office, many people gather in such places, and quickly the air becomes thick. This is partly due to the increased humidity. Ventilation systems are commonly used in office and administrative buildings to dehumidify rooms and ensure a comfortable atmosphere. Mechanical dehumidification works reliably, but it costs energy and — depending on the electricity used — has a negative climate impact.
Engineers from Australia and China have invented a sponge-like device that captures water from thin air and then releases it in a cup using the sun’s energy, even in low humidity where other technologies such as fog harvesting and radiative cooling have struggled.
Researchers have created a 98-milligram sensor system — about one tenth the weight of a jellybean or less than one-hundredth of an ounce — that can ride aboard a small drone or an insect, such as a moth, until it gets to its destination. Then, when a researcher sends a Bluetooth command, the sensor is released from its perch and can fall up to 72 feet — from about the sixth floor of a building — and land without breaking. Once on the ground, the sensor can collect data, such as temperature or humidity, for almost three years.
Low-cost jelly-like materials, developed by researchers at the University of Cambridge, can sense strain, temperature, and humidity. And unlike earlier self-healing robots, they can also partially repair themselves at room temperature.
As automotive technology advances, the need for comprehensive environmental awareness becomes increasingly critical for vehicle safety and efficiency. This study introduces a novel integrated wind, weather, and motion sensor designed for moving objects, with a focus on automotive applications. The sensor’s potential to enhance vehicle performance by providing real-time data on local atmospheric conditions is investigated. The research employs a combination of sensor design, vehicle integration, and field-testing methodologies. Findings prove the sensor’s capability to accurately capture dynamic environmental parameters, including wind speed and direction, temperature, and humidity. The integration of this sensor system shows promise in improving vehicle stability, optimizing fuel efficiency through adaptive aerodynamics, and enhancing the performance of autonomous driving systems. Furthermore, the study explores the potential of this technology in contributing to connected vehicle ecosystems and smart traffic management. The integration of such advanced sensing capabilities represents a significant step towards safer, more efficient, and environmentally responsive automotive systems.
The purpose of air conditioning (AC) duct packing is multifaceted, serving to prevent condensation, eliminate rattle noise, and provide thermal insulation. A critical aspect of duct packing is its adhesive quality, which is essential for maintaining the longevity and effectiveness of the packing's functions. Indeed, the challenge of achieving adequate adhesivity on AC ducting parts is significant due to the harsh operating conditions to which these components are subjected. The high temperatures and presence of condensation within the AC system can severely compromise the adhesive's ability to maintain a strong bond. Moreover, the materials used for these parts, such as HDPE, often have low surface energy, which further hinders the formation of a durable adhesive bond. The failure of the adhesive under these conditions can lead to delamination of the duct packing, which can result in customer inconvenience due to rattling noises, potential electrical failures if condensed water contacts electrical components beneath the ducting, or loss of thermal energy, thereby reducing the AC system's thermal efficiency. This paper primarily focuses on developing an experimental methodology to identify the most appropriate adhesive for use in ducting applications. This involves a detailed examination of various adhesive types and designing suitable experiments to evaluate the adhesive bond's resilience, particularly when applied to HDPE blow-molded ducts. The methodology aims to ascertain the conditions under which the adhesive bond fails, ensuring that the selected adhesive can maintain its integrity under the rigors of operational stress and environmental factors. Additional insights gained from the study highlight the influence of surface roughness, resting time, and exposure to extreme temperatures on the lamination quality of duct packing. These findings are crucial for manufacturers to consider when selecting adhesives for AC duct systems, ensuring that the chosen solutions are robust enough to withstand the demanding conditions of automotive environments and maintain the integrity and functionality of the duct packing over time.
Moisture adsorption and compression deformation behaviors of Semimet and Non-Asbestos Organic brake pads were studied and compared for the pads cured at 120, 180 and 240 0C. The 2 types of pads were very similar in moisture adsorption behavior despite significant differences in composition. After being subjected to humidity and repeated compression to 160 bars, they all deform via the poroviscoelastoplastic mechanism, become harder to compress, and do not fully recover the original thickness after the pressure is released for 24 hours. In the case of the Semimet pads, the highest deformation occurs with the 240 °C-cure pads. In the case of the NAO pads, the highest deformation occurs with the 120 0C-cure pads. In addition, the effect of pad cure temperatures and moisture adsorption on low-speed friction was investigated. As pad properties change all the time in storage and in service because of continuously changing humidity, brake temperature and pressure, one must question any approach trying to relate unused virgin pad properties to brake friction and noise in service, including any attempt to model or simulate brake friction and noise using virgin pad properties.
Corrosion occurs in diverse environments mainly on metallic parts. Helicopters are made of a huge percentage of metallic parts and need to have several maintenance steps to guarantee its functioning and its durability. The military helicopters are flying in different kinds of environment, which cover large spectrum of severity of the atmospheric corrosion [1]. In maritime conditions, the most influencing factor is the Time of Wetness, which is a direct result Relative Humidity and Salt loading. The main material used for aircraft and that is suffering from corrosion is aluminium. There are plenty of data to follow the corrosion as a function of the environmental conditions, mainly on the sensitivity with sodium chloride, Relative Humidity, film thickness, etc... [2][3]. The maintenance efficiency on helicopters is dependent on the environmental severity. The U.S. armed forces estimate $10.2 billion in corrosion costs for their aviation and missile fleets during 2016 [4] [5] [6]. The aim of the present analysis consists of defining the Condition Based Maintenance related to corrosion risk to better apply a maintenance program when it is really needed.
Focused on the permanent magnet synchronous motor (PMSM) used in electric, this paper proposes an online insulation testing method based on voltage injection under high-temperature and high-humidity conditions. The effect of constant humidity and temperature on the insulation performance has been also studied. Firstly, the high-voltage insulation structure and principle of PMSM are analyzed, while an electrical insulation testing method considered constant humidity and temperature is proposed. Finally, a temperature and humidity experimental cycling test is carried out on a certain prototype PMSM, taking heat conduction and radiation models, water vapor, and partial discharge into account. The results show that the electrical insulation performance of the motor under constant humidity and temperature operation environment exhibits a decreasing trend. This study can provide theoretical and practical references for the reliable durability design of PMSM.
In the last decades there have been many temporary engine failures, engine-related events and erroneous airspeed indication measurements that occurred by a phenomenon known as Ice Crystal Icing (ICI). This type of icing mainly occurs in high altitudes close to tropical convection in areas with a high concentration of ice crystals. Direct measurements or in-situ pilot observations of ICI that could be used as a warning to other air-traffic are rare to nearly non-existent. To detect those dangerous high Ice Water Content (IWC) areas with already existing airborne measurement instruments, Lufthansa analyzed observed Total Air Temperature (TAT) anomalies and used a self-developed search algorithm, depicting those TAT anomalies that are related to ice crystal icing events. To optimize the flight route for dispatchers several hours before the flight, e.g. for long distance flights through the intertropical convergence zone (ITCZ), reliable forecasts to identify hazardous high IWC regions are necessary. For this purpose, detected TAT anomalies were used as training data to find correlations in between these and the DWD’s ICON (ICOsahedral Non-hydrostatic) model output. The combination of obtained frequency distributions of model cloud ice water content, base and top of moist convection and specific humidity by a fuzzy logic leads to a model-based prototype to forecast areas with high IWC in a simple manner. To show the high potential of the prototype’s procedure, an ICI event as observed during the CIRRUS-HL (Cirrus in High Latitudes) flight campaign in 2021 serves as good validation case. Here we show first promising, as it is still under development.
Considerable amounts of water accumulate in aircraft fuel tanks due to condensation of vapor during flight or directly during fueling with contaminated kerosene. This can result in a misreading of the fuel meters. In certain aircraft types, ice blocks resulting from the low temperatures at high altitude flights or in winter time can even interfere with the nozzles of the fuel supply pipes from the tanks to the engines. Therefore, as part of the maintenance operations, water has to be drained in certain intervals ensuring that no remaining ice is present. In the absence of an established method for determining residual ice blocks inside, the aircraft operator has to wait long enough, in some cases too long, to start the draining procedure, leading potentially to an unnecessary long ground time. A promising technology to determine melting ice uses acoustic signals generated and emitted during ice melting. With acoustic emissions, mainly situated in the ultrasonic frequency range, a very high number of events can be recorded to characterize stress relaxation processes that occur during conversions from ice to water. In the present paper, in addition to the case of the fuel tank, the icing of a fuselage panel is also considered. The results obtained provide evidence that it is possible to determine the moment when all ice has melted. However, it is not possible to give exact figures on the amount of ice remaining or melted, which is not a limitation in practice.
This method is used to define the immunity of electric and electronic apparatus and equipment (products) to radiated electromagnetic (EM) energy. This method is based on injecting the calibrated radio frequency currents (voltages) into external conductors and/or internal circuits of the product under test, measuring the strength of the EM field generated by this product and evaluating its immunity to the external EM field on the basis of the data obtained. The method can be utilized only when it is physically possible to connect the injector to the conductors and/or circuits mentioned before. The method allows: Evaluating immunity of the product under test to external EM fields of the strength equal to a normalized one; Calculating the level of external EM field strength at which the given (including maximum permissible) induced currents or voltages are generated in the equipment under test, or solving the “opposite” task; Finding potentially “weak” points of the product design (housing, shield, etc.), through which EM energy can enter inside the product. The method capabilities mentioned above define the sphere of its application: Measurements of electronic product immunity to external EM fields at different conditions (polygons, laboratories, in-situ) as an alternative to direct test methods; Operating instruments for a designer working out the product of a given immunity to external EM fields. This method can’t be directly applied to evaluate the immunity of the equipment under test to the pulse electromagnetic fields. But it can be used to get the initial data necessary to solve this task.
A typical modern automobile compressor-driven air conditioner, about powerful enough to cool a house, may not be needed even in very hot, humid climates if we combine insights from comfort theory with innovations in comfort delivery, photonics, and superefficient thermal and air-handling devices. Recent advances can successively minimize unwanted heat gain into the passenger cabin, cool people’s bodies rather than the vehicle, deliver highly effective radiant cooling, passively reject extracted heat to the sky, and, if needed, move air very efficiently and quietly to expand the human comfort range. Together these proven innovations may give automotive occupants excellent hot-weather comfort without refrigerative air conditioning. This substitution could improve climate protection and electric-vehicle range, cut the automobile’s weight and cost, avoid climate and ozone harm from refrigerants, reduce noise and air pollution, make autos more energy-efficient, and save the United States gasoline costing many billions of dollars per year. Prompt experimental tests of such integrative designs are warranted.
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