Experimental study on transmission performance of harmonic drive under multifactor interaction

2019 ◽  
Vol 20 (6) ◽  
pp. 614
Author(s):  
Guangwu Zhou ◽  
Zhenhua Zhang ◽  
Hua Zhang
Keyword(s):  
Working Conditions ◽  
High Performance ◽  
Interaction Analysis ◽  
Space Environment ◽  
Mechanism Analysis ◽  
Harmonic Drive ◽  
Analysis Method ◽  
Transmission Performance ◽  
Traditional Performance ◽  
Starting Torque

In space environment and complex working conditions, the harmonic drive is prone to performance degradation. The traditional performance analysis method cannot reveal the interaction among the factors. In this paper, a mathematical model of multifactor interaction analysis is built to analyze transmission performance of efficiency, stiffness, and starting torque in various temperature, vacuum, speed and torque. And the high performance gear transmission platform is independently designed and developed. The experimental research and mechanism analysis are carried out on the starting torque, stiffness and efficiency of the harmonic drive. Research shows that the multifactor interaction has an important impact on the transmission performance of harmonic drive. The approach provides some guidance for the application of harmonic drive in space.

Development of Simultaneous Analysis Method for Multi-Compounds Content of New Shilajit Using HPLC-UV and the Cognitive Enhancing Effect: Mongolian Shilajit

2021 ◽  
Vol 16 (7) ◽  
pp. 1934578X2110304
Author(s):  
SukJin Lee ◽  
HyeSung Ryu ◽  
WanKyunn Whang
Keyword(s):  
Quality Control ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
High Resolution Mass Spectrometry ◽  
Radical Scavenging ◽  
Original Material ◽  
Analysis Method ◽  
Quality Control Standard ◽  
Quantitative Hplc Analysis

Shilajit has a longstanding use as an anti-aging and memory enhancing drug. It is known to have excellent anti-bacterial effects and is believed to be effective for cognitive enhancement, but is difficult to standardize because of the lack of quality control standards. This study, for the first time, proposes a quality control standard using a simultaneous analytical method for the drug’s multi-compound content using high-performance liquid chromatography-ultraviolet detection (HPLC-UV) as an aid for the internationalization of Mongolian Shilajit. Phenolic compounds 1-6 were isolated from Mongolian Shilajit extract using bioassay-guided isolation, and the isolated compounds were evaluated for cognitive-related anti-Alzheimer’s disease (AD) activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), β-site amyloid precursor protein-cleaving enzyme 1 (BACE1), and advanced glycation end-product (AGE) formation assays. The isolated compounds showed good effects for each activity. In addition, the isolated compounds were successfully quantified using a validated quantitative HPLC analysis method. As a result, the isolated compounds were suggested as standard marker compounds for Mongolian Shilajit. Also, we proved that the original material of Mongolian Shilajit is a lichen named Xanthoparmelia somloensis (Gyel.) Hale using HPLC-UV, ultra-high-performance liquid chromatography-electrospray ionization/hybrid linear trap-quadruple-orbitrap-high-resolution mass spectrometry (UHPLC-ESI/LTQ-HRMS).

scholarly journals Kynurenine pathway in post-mortem prefrontal cortex and cerebellum in schizophrenia: relationship with monoamines and symptomatology

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Amira Ben Afia ◽  
Èlia Vila ◽  
Karina S. MacDowell ◽  
Aida Ormazabal ◽  
Juan C. Leza ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
High Performance ◽  
Interaction Analysis ◽  
Kynurenine Pathway ◽  
Psychotic Symptoms ◽  
Post Mortem ◽  
Control Subjects ◽  
Network Interaction ◽  
Hydroxyindoleacetic Acid ◽  
Cortical Circuit

Abstract Background The cortico-cerebellar-thalamic-cortical circuit has been implicated in the emergence of psychotic symptoms in schizophrenia (SZ). The kynurenine pathway (KP) has been linked to alterations in glutamatergic and monoaminergic neurotransmission and to SZ symptomatology through the production of the metabolites quinolinic acid (QA) and kynurenic acid (KYNA). Methods This work describes alterations in KP in the post-mortem prefrontal cortex (PFC) and cerebellum (CB) of 15 chronic SZ patients and 14 control subjects in PFC and 13 control subjects in CB using immunoblot for protein levels and ELISA for interleukins and QA and KYNA determinations. Monoamine metabolites were analysed by high-performance liquid chromatography and SZ symptomatology was assessed by Positive and Negative Syndrome Scale (PANSS). The association of KP with inflammatory mediators, monoamine metabolism and SZ symptomatology was explored. Results In the PFC, the presence of the anti-inflammatory cytokine IL-10 together with IDO2 and KATII enzymes decreased in SZ, while TDO and KMO enzyme expression increased. A network interaction analysis showed that in the PFC IL-10 was coupled to the QA branch of the kynurenine pathway (TDO-KMO-QA), whereas IL-10 associated with KMO in CB. KYNA in the CB inversely correlated with negative and general PANSS psychopathology. Although there were no changes in monoamine metabolite content in the PFC in SZ, a network interaction analysis showed associations between dopamine and methoxyhydroxyphenylglycol degradation metabolite. Direct correlations were found between general PANSS psychopathology and the serotonin degradation metabolite, 5-hydroxyindoleacetic acid. Interestingly, KYNA in the CB inversely correlated with 5-hydroxyindoleacetic acid in the PFC. Conclusions Thus, this work found alterations in KP in two brain areas belonging to the cortico-cerebellar-thalamic-cortical circuit associated with SZ symptomatology, with a possible impact across areas in 5-HT degradation.

scholarly journals Refined Vehicle-Bridge Interaction Analysis Using Incompatible Solid Finite Element for Evaluating Stresses and Impact Factors

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Qing Xie ◽  
Wanshui Han ◽  
Yangguang Yuan
Keyword(s):  
Finite Element ◽  
Computational Efficiency ◽  
Interaction Analysis ◽  
Computational Cost ◽  
Point Contact ◽  
Time History ◽  
Analysis Method ◽  
Heavy Vehicles ◽  
Solid Element ◽  
Bridge Responses

The vehicle-bridge interaction can induce bridge vibration and consequently fatigue, durability deterioration, local damage, and even collapse of bridge structure. In this paper, a solid vehicle-bridge interaction (VBI) analysis method is developed to provide refined analysis on the bridge responses including displacement and local stress under vehicle loads. The incompatible solid finite element (FE) is introduced to model the bridge, where the element shear locking is alleviated by incompatible displacement modes without sacrificing the computational efficiency. Benchmark example shows the incompatible solid element has superior computational efficiency compared to the conventional solid element. By virtue of the mass-spring-damper vehicle model, the interaction between vehicle and bridge is simulated with point-to-point contact assumption and the coupled dynamic equations are solved via nonlinear iteration. A case study on a simply supported T-girder bridge is conducted to validate the developed solid VBI analysis method and then the dynamic impact factor (DIF) of the bridge is evaluated based on the computed stress results and compared to code values. Results show that the solid VBI analysis method yields more accurate time-history bridge responses including displacement and stress under moving vehicles than the grillage method despite higher computational cost. Particularly, it can simulate realistic stress distribution and concentration along any concerned sections as well as in local components, which can provide detail information on the bridge behavior under dynamic loads. On the other hand, the DIF based on the computed stress result generally agrees well with the code values except for heavy vehicles where the stress-based DIF is slightly higher than the value in Chinese code while lower than that of AASHTO, suggesting the value specified by Chinese code may underestimate the DIF of heavy vehicles in certain circumstances to which more attention should be paid.

scholarly journals Study on Three-Dimensional Analysis Method of Radiation Dose of GEO Satellite

2019 ◽  
Vol 288 ◽  
pp. 02010
Author(s):  
Chunsheng Xu ◽  
Yang Zhang ◽  
Hui Liu ◽  
Yong Yang ◽  
Yongquan Xia
Keyword(s):  
Radiation Dose ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Space Environment ◽  
Analysis Method ◽  
Reliability Design ◽  
Satellite Design ◽  
Geo Satellite ◽  
Depth Analysis ◽  
D Model

GEO satellite in orbit is greatly affected by the total radiation dose of space environment. In order to meet the requirements of satellite reliability design, radiation dose analysis is an important work in the process of satellite design. Previous radiation dose analysis is based on one-dimensional dose-depth analysis, or three-dimensional analysis, but over-simplified 3-D model may cause the analysis results deviated different from the reality. This paper presents a three-dimensional radiation dose analysis method based on the actual 3-D model of satellite. This method could analyze radiation dose with actual models, which could be automatically simplified according to needs. It could automatically extract the attribute information in the model and calculate the radiation dose value in each subspace

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