Shaft Surface Finish Is an Important Part of the Sealing System

1968 ◽  
Vol 90 (2) ◽  
pp. 375-381 ◽  
Author(s):  
W. O. Heyn
Keyword(s):  
Abrasive Wear ◽  
Surface Finish ◽  
Poor Performance ◽  
Special Method ◽  
Plunge Grinding ◽  
System A ◽  
Shaft Seals ◽  
Shaft Surface ◽  
Selection Of

Current specifications for shaft finishes to be used with shaft seals are inadequate. Many finishes which meet these current specifications do not perform well in sealing applications because they can cause either leakage or abrasive wear of the seal lip. The practice of leaving the selection of the process to produce the finish up to the shaft manufacturer may lead to poor performance of the sealing system. A new shaft finish specification is proposed which specifies a process to obtain a satisfactory sealing surface. It has been found that machine lead can be generated by plunge grinding. Grinding procedures for avoiding machine lead during plunge grinding are listed. In order to be certain that machine lead is not present, the surface must be inspected for it. Therefore, a special method for checking for machine lead is recommended.

scholarly journals Sensitivity Based Selection of an Optimal Cable-Driven Parallel Robot Design for Rehabilitation Purposes

Robotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Ferdaws Ennaiem ◽  
Abdelbadiâ Chaker ◽  
Juan Sebastián Sandoval Arévalo ◽  
Med Amine Laribi ◽  
Sami Bennour ◽  
...  
Keyword(s):  
Pareto Front ◽  
Parallel Robot ◽  
Elastic Stiffness ◽  
Upper Limb Rehabilitation ◽  
Daily Life Activities ◽  
System A ◽  
The Monte Carlo Method ◽  
Genetic Algorithm Method ◽  
Limb Rehabilitation ◽  
Selection Of

This paper deals with the design of an optimal cable-driven parallel robot (CDPR) for upper limb rehabilitation. The robot’s prescribed workspace is identified with the help of an occupational therapist based on three selected daily life activities, which are tracked using a Qualisys motion capture system. A preliminary architecture of the robot is proposed based on the analysis of the tracked trajectories of all the activities. A multi-objective optimization process using the genetic algorithm method is then performed, where the cable tensions and the robot size are selected as the objective functions to be minimized. The cables tensions are bounded between two limits, where the lower limit ensures a positive tension in the cables at all times and the upper limit represents the maximum torque of the motor. A sensitivity analysis is then performed using the Monte Carlo method to yield the optimal design selected out of the non-dominated solutions, forming the obtained Pareto front. The robot with the highest robustness toward the disturbances is identified, and its dexterity and elastic stiffness are calculated to investigate its performance.

scholarly journals An Analytical Approach for the Selection of Technologies to be Integrated in a Plug&play Façade Unit: The RenoZEB Case Study

Proceedings ◽  
2021 ◽  
Vol 65 (1) ◽  
pp. 29
Author(s):  
Alessandro Pracucci ◽  
Sara Magnani ◽  
Laura Vandi ◽  
Oscar Casadei ◽  
Amaia Uriarte ◽  
...  
Keyword(s):  
Building Envelope ◽  
Design System ◽  
Decision Matrix ◽  
Design Guideline ◽  
Existing Building ◽  
Building Conditions ◽  
Zero Energy Building ◽  
System A ◽  
Selection Of

The nearly Zero Energy building (nZEB) renovation market is currently the key feature in the construction sector. RenoZEB aims to develop a systematic approach for retrofitting by assembling different technologies in a plug and play building envelope. This paper presents the methodology used to transform the RenoZEB concept in the design system. A multi-criteria decision matrix is used for the selection of the best façade technologies within the market while the analysis of the existing building conditions allows to develop a replicable approach for designing deep retrofitting intervention through a plug&play façade. The methodology appears to be a valuable support for the selection of technologies and allows to define a design guideline for the envelope.

Occupational Fatigue Risk Assessment and Management System: A Systematic Review and Bibliometric Analysis

2021 ◽  
Vol 65 (1) ◽  
pp. 482-483
Author(s):  
Mundhir Nasser Al Alawi ◽  
Suman Kanti Chowdhury
Keyword(s):  
Management System ◽  
Human Error ◽  
Poor Performance ◽  
Industrial Sector ◽  
Theoretical Frameworks ◽  
System A ◽  
Current State ◽  
Emerging Trends ◽  
Activity Types ◽  
Occupational Fatigue

An occupational fatigue risk management system (FRMS) framework can aid practitioners to reduce the fatigue-induced human error, poor performance, and the risk of injury in the industrial settings. However, the current state-of-knowledge on different theoretical frameworks of FRMS adopted in various occupational settings has not been systematically mapped in terms of risk factors, industrial sector types, activity types, and interventions. Therefore, this study aimed to review and characterize the previous literature on FRMS available in the ISI Web of Science (WoS) database and applied various bibliometric approaches to explore current state-of-knowledge, emerging trends and future directions. The data for the analyses were collected from the 68 articles published in 24 various journals between 2001 and 2021. The trend showed a rapid increase in FRMS research in the last seven years, especially in healthcare and aviation industries. Future studies should consider environmental stressors while designing a holistic framework of FRMS.

scholarly journals CB1 Activity Drives the Selection of Navigational Strategies: A Behavioral and c-Fos Immunoreactivity Study

2020 ◽  
Vol 21 (3) ◽  
pp. 1072
Author(s):  
Daniela Laricchiuta ◽  
Francesca Balsamo ◽  
Carlo Fabrizio ◽  
Anna Panuccio ◽  
Andrea Termine ◽  
...  
Keyword(s):  
Spatial Learning ◽  
Dorsal Striatum ◽  
Endocannabinoid System ◽  
Cognitive Map ◽  
Cb1 Receptors ◽  
Spatial Problem ◽  
System A ◽  
Hole Board ◽  
Selection Of

To promote efficient explorative behaviors, subjects adaptively select spatial navigational strategies based on landmarks or a cognitive map. The hippocampus works alone or in conjunction with the dorsal striatum, both representing the neuronal underpinnings of the navigational strategies organized on the basis of different systems of spatial coordinate integration. The high expression of cannabinoid type 1 (CB1) receptors in structures related to spatial learning—such as the hippocampus, dorsal striatum and amygdala—renders the endocannabinoid system a critical target to study the balance between landmark- and cognitive map-based navigational strategies. In the present study, mice treated with the CB1-inverse agonist/antagonist AM251 or vehicle were trained on a Circular Hole Board, a task that could be solved through either navigational strategy. At the end of the behavioral testing, c-Fos immunoreactivity was evaluated in specific nuclei of the hippocampus, dorsal striatum and amygdala. AM251 treatment impaired spatial learning and modified the pattern of the performed navigational strategies as well as the c-Fos immunoreactivity in the hippocampus, dorsal striatum and amygdala. The present findings shed light on the involvement of CB1 receptors as part of the selection system of the navigational strategies implemented to efficiently solve the spatial problem.

scholarly journals Analysis of alternative ventilation strategies for existing multi-family buildings using CONTAM simulation software

2020 ◽  
Vol 172 ◽  
pp. 09004
Author(s):  
Xinxiu Tian ◽  
Jamie Fine ◽  
Marianne Touchie
Keyword(s):  
Ventilation System ◽  
Poor Performance ◽  
Simulation Software ◽  
Base Case ◽  
Building Model ◽  
System A ◽  
Airflow Distribution ◽  
Air Ventilation ◽  
Ventilation Strategies ◽  
Post War

In many existing high-rise multi-family buildings, a pressurized corridor ventilation system is used to meet outdoor air ventilation requirements. However, this system often has poor performance, leading to under- or over- ventilation in different parts of a building. This study examines three ventilation strategies including: the base case, which is a traditional pressurized corridor ventilation system, a direct-to-suite ducted ventilation system, and a suite-based HRV ventilation system. A building model was constructed in CONTAM using features of a typical post-war multi-family building in Toronto, Canada. All three strategies were simulated using CONTAM under both summer and winter conditions. The resulting outdoor airflow delivery rates to the suites and corridor pressure differentials were compared to assess the effectiveness of each strategy. The results show that the suite-based HRV strategy is able to provide adequate ventilation airflow to individual suites in both summer and winter. In the traditional pressurized corridor system and the direct-to-suite ducting system, the airflows delivered to the suites located at the top of the building are higher than those delivered to the suites located at the bottom of the building. This uneven airflow distribution is more pronounced in winter when stack effect impacts the ventilation system more significantly.

Exploring the policy selection of the P2P VoD system: A simulation-based research

2014 ◽  
Vol 8 (3) ◽  
pp. 459-473 ◽  
Author(s):  
Ke Xu ◽  
Xin Liu ◽  
Zhen Ma ◽  
Yifeng Zhong ◽  
Wenlong Chen
Keyword(s):  
System A ◽  
Policy Selection ◽  
Simulation Based ◽  
Selection Of
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