scholarly journals Investigation of Characteristics of a Novel Torque Motor Based on an Annulus Air Gap

Machines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 131
Author(s):  
Bin Meng ◽  
Mingzhu Dai ◽  
Chenhang Zhu ◽  
Hao Xu ◽  
Wenang Jia ◽  
...  
Keyword(s):  
Negative Feedback ◽  
Gap Analysis ◽  
Back Propagation ◽  
Feedback Mechanism ◽  
Air Gap ◽  
Spiral Groove ◽  
Negative Feedback Mechanism ◽  
Output Torque ◽  
Orthogonal Tests ◽  
Torque Angle

Although a two-dimensional (2D) valve has excellent performance, the processing of its spiral groove has a high cost and is time-consuming. This paper proposes a novel torque motor based on an annulus air gap (TMAAG) to replace the negative feedback function of the spiral groove to reduce the machining difficulty. In order to study the torque change law of the TMAAG, the air gap permeance was analyzed, and then a qualitative analytical model was established. Orthogonal tests were carried out to initially select the crucial parameters, which were further optimized through a back propagation (BP) neural network and genetic algorithm. The prototype of TMAAG was machined, and a special experimental platform was built, and experiment results are similar to the simulation values, which verifies the accuracy of the air gap analysis and qualitative model. For torque-angle characteristics, the output torque increases with both current and rotation angle and reaches about 0.754 N·m with 2 A and 1.5°. While for torque-displacement characteristics, due to the negative feedback mechanism, the output torque decreases with increasing armature displacement, which is about 0.084 N·m with 2 A and 1 mm. The research validates the unique negative feedback mechanism of the TMAAG and indicates that it can be potentially used as an electro-mechanical converter of a 2D valve.

Activation of the Na+/K+-ATPase by insulin and glucose as a putative negative feedback mechanism in pancreatic beta-cells

2008 ◽  
Vol 457 (6) ◽  
pp. 1351-1360 ◽  
Author(s):  
M. Düfer ◽  
D. Haspel ◽  
P. Krippeit-Drews ◽  
L. Aguilar-Bryan ◽  
J. Bryan ◽  
...  
Keyword(s):  
Beta Cells ◽  
Negative Feedback ◽  
Pancreatic Beta Cells ◽  
Feedback Mechanism ◽  
Negative Feedback Mechanism

scholarly journals Negative feedback in ants: crowding results in less trail pheromone deposition

2013 ◽  
Vol 10 (81) ◽  
pp. 20121009 ◽  
Author(s):  
Tomer J. Czaczkes ◽  
Christoph Grüter ◽  
Francis L. W. Ratnieks
Keyword(s):  
Negative Feedback ◽  
Trail Pheromone ◽  
Distribution Networks ◽  
Feedback Mechanism ◽  
Lasius Niger ◽  
Feedback Signal ◽  
Control Mechanisms ◽  
Negative Feedback Mechanism ◽  
Self Organized ◽  
Fold Reduction

Crowding in human transport networks reduces efficiency. Efficiency can be increased by appropriate control mechanisms, which are often imposed externally. Ant colonies also have distribution networks to feeding sites outside the nest and can experience crowding. However, ants do not have external controllers or leaders. Here, we report a self-organized negative feedback mechanism, based on local information, which downregulates the production of recruitment signals in crowded parts of a network by Lasius niger ants. We controlled crowding by manipulating trail width and the number of ants on a trail, and observed a 5.6-fold reduction in the number of ants depositing trail pheromone from least to most crowded conditions. We also simulated crowding by placing glass beads covered in nest-mate cuticular hydrocarbons on the trail. After 10 bead encounters over 20 cm, forager ants were 45 per cent less likely to deposit pheromone. The mechanism of negative feedback reported here is unusual in that it acts by downregulating the production of a positive feedback signal, rather than by direct inhibition or the production of an inhibitory signal.

scholarly journals RGS4 is a negative feedback mechanism of Angiotensin II‐mediated aldosterone production in human adrenal cells

2006 ◽  
Vol 20 (4) ◽  
Author(s):  
Damian G Romero ◽  
Maria W Plonczynski ◽  
Licy L Yanes ◽  
Tanganika R Washington ◽  
Gina Covington ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Negative Feedback ◽  
Feedback Mechanism ◽  
Adrenal Cells ◽  
Negative Feedback Mechanism ◽  
Aldosterone Production

Intrinsic and extrinsic mechanisms contribute to maintain the JAK/STAT pathway aberrantly activated in T-type large granular lymphocyte leukemia

Blood ◽  
2013 ◽  
Vol 121 (19) ◽  
pp. 3843-3854 ◽  
Author(s):  
Antonella Teramo ◽  
Cristina Gattazzo ◽  
Francesca Passeri ◽  
Albana Lico ◽  
Giulia Tasca ◽  
...  
Keyword(s):  
Negative Feedback ◽  
Feedback Mechanism ◽  
Large Granular Lymphocyte ◽  
Large Granular Lymphocyte Leukemia ◽  
Negative Feedback Mechanism ◽  
Key Points ◽  
Stat Pathway

Key PointsIn T-LGLL, autologous LGL-depleted PBMCs release high levels of IL-6 contributing to the constitutive STAT3 activation in leukemic LGL. Leukemic LGLs show SOCS3 down-modulation, which is responsible for lack of the negative feedback mechanism controlling STAT3 activation.

scholarly journals Studies on the Physiological Role of Hypothalamic TRH on the Negative Feedback Mechanism of the Pituitary-Thyroid Axis

1979 ◽  
Vol 55 (6) ◽  
pp. 776-786
Author(s):  
Masatomo MORI ◽  
Kihachi OHSHIMA ◽  
Sakae MARUTA ◽  
Hitoshi FUKUDA ◽  
Yohnosuke SHIMOMURA ◽  
...  
Keyword(s):  
Negative Feedback ◽  
Physiological Role ◽  
Feedback Mechanism ◽  
Negative Feedback Mechanism ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis

scholarly journals A Repressor of GATA-Mediated Negative Feedback Mechanism of T Cell Activation

2003 ◽  
Vol 172 (1) ◽  
pp. 170-177 ◽  
Author(s):  
Shi-Chuen Miaw ◽  
Bok Yun Kang ◽  
Ian Alexander White ◽  
I-Cheng Ho
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Negative Feedback ◽  
Cell Activation ◽  
Feedback Mechanism ◽  
Negative Feedback Mechanism

A new negative feedback mechanism for balancing Tibet uplift-driven CO2 drop: Evidence from Paleogene chemical weathering records in the northern Tibetan Plateau

2020 ◽  
Author(s):  
Xiaomin Fang ◽  
Albert Galy ◽  
Yibo Yang ◽  
Weilin Zhang ◽  
Chengcheng Ye ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Carbon Cycle ◽  
Negative Feedback ◽  
Feedback Mechanism ◽  
Global Temperature ◽  
Silicate Weathering ◽  
Negative Feedback Mechanism ◽  
Northern Tibetan Plateau ◽  
Organic Carbon Burial ◽  
Global Cooling

<p>The CO<sub>2</sub> degassing by plate tectonic process has long been thought to be balanced by weathering of silicate rocks on continents, keeping the Earth a relative stable global carbon cycle and temperature suitable for life creation, survival and evolution. The uplift of the Tibetan Plateau (TP) is hypothesized to enhance erosion and silicate weathering and organic carbon burial, thus cool the global temperature. However, the imbalance resulting from accelerated CO<sub>2</sub> consumption by uplift of the TP and a relatively stable CO<sub>2</sub> input from volcanic degassing during the Cenozoic should have depleted atmospheric CO<sub>2</sub> within a few million years; therefore, a negative feedback mechanism must have stabilised the carbon cycle. Here, we present the first almost complete Paleogene silicate weathering intensity (SWI) records from continental rocks in the northern TP, based on detailed volcanic ash and paleomagnetic dating of two continuous Cenozoic sections in the Xining and Qaidam Basin in NW China. They show that the Paleogene silicate weathering in this tectonically inactive area was modulated by global temperature. These findings suggest that Paleogene global cooling was also strongly influenced by the temperature feedback mechanism that regulated silicate weathering rates and hydrological cycles and maintained a nearly stable carbon cycle. It acted as a negative feedback through decreasing CO<sub>2</sub> consumption resulting from the lower SWI and the kinetic limitations in tectonically inactive areas that followed the global cooling. This means that the enhanced erosion and silicate weathering by the uplift of the south and central Tibetan Plateau, thus accelerated CO<sub>2</sub> consumption, must be compensated by reducing CO<sub>2</sub> consumption of the rest vast continents through their reduced silicate weathering from cooling.</p>

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