Soil aggregation returns to a set point despite seasonal response to snow manipulation

Geoderma ◽  
2020 ◽  
Vol 357 ◽  
pp. 113954 ◽  
Author(s):  
Edward P. Boswell ◽  
Nick J. Balster ◽  
Alex W. Bajcz ◽  
Anita M. Thompson
2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Fina Supegina

Hydroponics is one of planting method that use water as a medium of plants growth, in this technique, mineral solution added into the water solvent, allowing the nutrient uptake process by the plants.  Farming by hydroponic method must pay attention to the following parameters namely, temperature, humidity, the level of water needs and nutrients and also the level of sunlight need for photosynthesis process.  This research used hydroponic technique in hydroponic growth room, and  there is a LED growth light as an alternate of sunlight, due to this room is closed without sunlight.  There are outputs displayed in monitoring system namely, temperature sensor, humidity sensor, ultrasound sensor to detect height of the plant and water level sensor to measured height of the water as a medium of the plant.  Results of measured sensor in hydroponic growth room explained as the following:  fan cooler worked when temperature , and humidity  .  Water pump worked when water level is less than 50% accordance set point.  Control on LED Growth Light and LED Bulb when LDR sensor reached set point > 500 in bright condition, and < 500 in dark condition respectively. The average of Time update/received data in thing speak web is 2.4 second. Keywords: Smart Control, Hydroponic, IoT, Monitoring


1980 ◽  
Vol 45 (11) ◽  
pp. 2903-2918 ◽  
Author(s):  
Josef Horák ◽  
Zina Valášková ◽  
František Jiráček

Algorithms have been presented, analyzed and experimentally tested to stabilize the reaction temperature at constant inlet temperature and composition of the feed by controlled dispensing of the catalyst. The information for the control element is the course of the reaction temperature. If the temperature of the reaction mixture is below the set point, the catalyst is being fed into the reactor at a constant rate. If the reaction temperature is higher the catalyst dispenser is blocked; dispensing of the catalyst is not resumed until the set point temperature has been reached again. The amount of catalyst added is a function of the duration of the switching cycle. The effect has been discussed of the form of this function on the course of the switching cycle. The results have been tested experimentally on a laboratory reactor controlled in an unstable steady state.


2021 ◽  
Vol 233 ◽  
pp. 110666
Author(s):  
Won Hee Kang ◽  
Yeobeom Yoon ◽  
Je Hyeon Lee ◽  
Kwan Woo Song ◽  
Young Tae Chae ◽  
...  
Keyword(s):  

2021 ◽  
Vol 27 (S1) ◽  
pp. 1148-1149
Author(s):  
Yuchen Zhang ◽  
Jiyoung Son ◽  
Qiaoyun Huang ◽  
Wenli Chen ◽  
Xiao-Ying Yu
Keyword(s):  

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 423
Author(s):  
Gun-Baek So

Although a controller is well-tuned for set-point tracking, it shows poor control results for load disturbance rejection and vice versa. In this paper, a modified two-degree-of-freedom (2-DOF) control framework to solve this problem is proposed, and an optimal tuning method for the pa-rameters of each proportional integral derivative (PID) controller is discussed. The unique feature of the proposed scheme is that a feedforward controller is embedded in the parallel control structure to improve set-point tracking performance. This feedforward controller and the standard PID con-troller are combined to create a new set-point weighted PID controller with a set-point weighting function. Therefore, in this study, two controllers are used: a set-point weighted PID controller for set-point tracking and a conventional PID controller for load disturbance rejection. The parameters included in the two controllers are tuned separately to improve set-point tracking and load dis-turbance rejection performances, respectively. Each controller is optimally tuned by genetic algo-rithm (GA) in terms of minimizing the IAE performance index, and what is special at this time is that it also tunes the set-point weighting parameter simultaneously. The simulation results performed on four virtual processes verify that the proposed method shows better performance in set-point tracking and load disturbance rejection than those of the other methods.


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