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Renewable Energy Sources for Modern Agricultural Trends
Published in Saravanan Krishnan, J Bruce Ralphin Rose, N R Rajalakshmi, Narayanan Prasanth, Cloud IoT Systems for Smart Agricultural Engineering, 2022
S. Arulvel, T. Joshva Devadas, D. Dsilva Winfred Rufuss, M. Amutha Prabakar
A pressure sensor is a device for pressure measurement in gases or liquids. Pressure is an expression of the force required to stop a fluid from expanding and is usually stated in terms of force per unit area. A pressure sensor usually acts as a transducer; it generates a signal as a function of the pressure imposed. The water pressure level can be changed in the planted area to reduce or increase the pressure to help the system to get back to the default mode/condition.
Fundamentals
Published in Mike Tooley, Lloyd Dingle, Engineering Science, 2020
Outer space is a vacuum and is completely devoid of matter; consequently there is no pressure in this vacuum. Therefore, pressure measurement relative to a vacuum is absolute. For most practical purposes it is only necessary to know how pressure varies from the earth's atmospheric pressure. A pressure gauge is designed to read zero when subject to atmospheric pressure; therefore, if a gauge is connected to a pressure vessel it will only read gauge pressure. So, to convert gauge pressure to absolute pressure, atmospheric pressure must be added to it, i.e. Absolute pressure = gauge pressure + atmospheric pressure.
Electrolyzer systems
Published in Leonard W. Casson, James W. Bess, Conversion to On-Site Sodium Hypochlorite Generation, 2019
Leonard W. Casson, James W. Bess
Air-cooled DC rectifiers are sometimes supplied with a fan pressure switch as a substitute for a vane type air flow switch or a pitot tube. Pressure switches can only be installed in equipment having an internal baffle at the diodes or thyristors to assure sufficient pressure. This pressure is a differential pressure measurement referenced to atmospheric pressure. Experience has demonstrated the necessity for a spare differential pressure switch available on-site. These switches are measuring pressure differences of 1/4- to 3 / 4 -inch water column against atmospheric conditions, are in generally harsh environments, and are prone to develop sticky diaphragm failures over extended operating times. Cooling fan motors and oil or water circulation pump motors are always supplied with their own safety circuits in accordance with local code requirements.
Nondestructive monitoring of freeze drying and spray freeze drying endpoint by temperature-pressure method
Published in Drying Technology, 2023
Fan Zhang, Yanhua Li, Qing Xu, Ruifeng Liu, Zhilong Wang, Chi Ma
The drying chamber is connected to a rotary vane vacuum pump (2XZ-8C, Tanshi, China) through a cold trap, and a resistance vacuum gauge (ZDR-II, Zhenghua, China) is installed on the pipeline between the cold trap and the drying chamber to keep the room temperature and avoid temperature affecting pressure measurement. A PT100 temperature sensor is set at the bottom of the drying chamber to monitor the ambient temperature of materials. To facilitate material collection, pallets are placed at the bottom of the drying chamber during testing. An electric heater is arranged at the bottom of the drying chamber to provide sublimation heat, which can reach the preset temperature in about 40 min. The refrigerator uses absolute ethanol for cycle refrigeration, and the refrigeration temperature is −80 °C. After cooling the circulating air through the condenser, it cools the drying chamber. The refrigeration temperature, fan working intensity, and electric heater working intensity are controlled by a Programmable Logic Controller (PLC). Figure 2 shows the physical picture of the whole machine and each working system.
Structure clearance design in wind tunnel tests with implications for aerodynamic drag of high-speed trains
Published in International Journal of Rail Transportation, 2022
Zhixiang Huang, Hanjie Huang, Weiping Zeng, Li Chen, Renyu Zhu
In the preceding aerodynamic design stage of a train, in which aerodynamic drag is a critical parameter in that stage, numerical simulation and model tests are mainly applied to investigate aerodynamic drag on HSTs. Stationary model tests have the advantages of high measurement accuracy and easy flow parameter control and are very suitable methods for the static aerodynamic characteristics evaluation and drag reduction assessment of prototype HSTs. In static force or pressure measurement tests, large HST models are preferred. Different from automobile tests, the moving belt technique is not used in stationary model tests due to large model lengths and requirements for ballast and track simulations. In Europe and China, fixed floors are generally used to simulate the ground effect during wind tunnel test studies on HSTs [15].
Automatic control of a freeze-drying process: Detection of the end point of primary drying
Published in Drying Technology, 2022
Several ways are currently available for the detection of the end point of primary drying, and the most promising are studied and compared in this paper. These techniques include:The product temperature response;Calorimetric methods;Spectroscopy methods applied to the lyophilized product;Gravimetric measurement;Methods based on gas composition in the product chamber (e.g., the comparative pressure measurement, electronic moisture sensors, etc.);Monitoring of controlled leakage of inert gas;Monitoring of condenser performance;The Pressure Rise Test (PRT);the opening frequency of the shut-off valve on the vacuum pump inlet.