Effects of operating conditions on cavitation induction of spiral groove liquid-film seal (SG-LFS)

2020 ◽  
Vol 72 (10) ◽  
pp. 1267-1275
Author(s):  
Zhentao Li ◽  
Xiaoli Yin ◽  
Jixiang Yue ◽  
Fuyu Liu ◽  
Muming Hao ◽  
...  
Keyword(s):  
Liquid Film ◽  
Relative Density ◽  
Peer Review ◽  
Design Methodology ◽  
Operating Conditions ◽  
Spiral Groove ◽  
Content Type ◽  
Relaxation Scheme ◽  
Cavitation Pressure ◽  
Lubricant Viscosity

Purpose The purpose of this paper is to study the effects of operating conditions including process coefficient, lubricant viscosity and cavitation pressure on the cavitation of spiral groove liquid-film seal (SG-LFS). Design/methodology/approach A mathematical model of SG-LFS is established based on the JFO boundary and a relative density is introduced. The universal governing equation after a coordinate transformation is discretized by the FVM method and solved by the Gauss-Seidel relaxation scheme. Findings The results indicate that the two-dimensional size of cavitation and cavitation degree are affected significantly by the process coefficient and lubricant viscosity but the effect of cavitation pressure can be ignored. Originality/value The effect mechanisms of operating conditions on the cavitation of SG-LFS are studied by the JFO boundary and cavitation degree characterized by a relative density. The results presented are helpful to perfect and deeply understand the cavitation mechanism of liquid-film seal. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0083/

Wisconsin Assistive Technology Initiative framework for supporting assistive technology decision-making in Singapore schools: perspectives of in-service educators

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Meng Ee Wong ◽  
YingMin Lee
Keyword(s):  
Decision Making ◽  
Assistive Technology ◽  
Peer Review ◽  
Design Methodology ◽  
Resource Constraints ◽  
Written Feedback ◽  
Technology Initiative ◽  
Content Type ◽  
Trial Experience ◽  
Practical Implications

PurposeThis study explored in-service educators' experience of using the Wisconsin Assistive Technology Initiative (WATI) for assistive technology (AT) decision-making within Singapore schools.Design/methodology/approachThe study adopted a qualitative design. Eight educators across both mainstream and special education schools were introduced to the WATI framework which they subsequently employed as a trial experience for a student under their care. Written feedback gathered from participants was analysed to identify common issues and themes regarding the use of the WATI framework for AT decision-making.FindingsThe comprehensive consideration of a broad scope of different factors, provision of a structured process for AT decision-making, as well as a common language for use by different stakeholders emerged as key benefits of implementing the WATI. Challenges encountered include administrative struggles in gathering different stakeholders together, time and resource constraints and difficulties in loaning AT devices for trial use.Practical implicationsBased on educators' feedback, recommendations to facilitate the adoption of the WATI for AT decision-making within Singapore schools are discussed and considered. This study also highlights the need for greater AT instruction within both preservice and in-service teacher preparation programmes in Singapore.Originality/valueSchools in Singapore currently rarely adopt any frameworks in place to guide educators through a systematic process of AT consideration. It is anticipated that this study will spearhead and drive the adoption of systematic frameworks such as the WATI for better AT decision-making within Singapore schools.Peer reviewThe peer review history for this article is available at: https://publons.com/publon 10.1108/JET-03-2021-0015

What makes peer review helpfulness evaluation in online review communities? An empirical research based on persuasion effect

2020 ◽  
Vol 44 (6) ◽  
pp. 1267-1286
Author(s):  
Yani Wang ◽  
Jun Wang ◽  
Tang Yao ◽  
Ming Li
Keyword(s):  
Peer Review ◽  
Design Methodology ◽  
Evaluation Research ◽  
Econometric Models ◽  
Online Review ◽  
Content Type ◽  
Review Helpfulness ◽  
New Perspective ◽  
The Relationship

PurposeThe purpose of this paper is to examine the mechanism of how peer review helpfulness evaluation in online review communities is established, drawing upon the internalization and identification routes of persuasion effect.Design/methodology/approachBased on book reviews selected from Douban.com (a prestigious review community in China), this study used econometric models to investigate the effects of both reviews and reviewers’ characteristics on peer review helpfulness evaluation in review communities.FindingsReview internalization is more persuasive than reviewers’ identification in peer evaluations, in terms of both short and long reviews. Reviews with extreme negative ratings tend to obtain higher level of helpfulness evaluation than those with positive or moderate ratings. The influence of reviewers’ characteristics is a significant cue in helping consumers to establish the trust perception in the context of short reviews, while its function diminishes in the context of long reviews, thus suggesting the importance of reviewers’ identification for short reviews in review communities.Social implicationsThe findings will enhance current understanding of peer review review helpfulness evaluation in online review communities and help practitioners administrate community reviews intelligently, help members write better reviews and customers in their product browsing experience.Originality/valueFirst, this study enriches review evaluation research in review communities by demonstrating the importance of internalization and identification lens of persuasion effect when explaining review helpfulness; second, this study helps to confirm the existing findings that reviews with extreme negative ratings are more helpful than those with moderate or positive ratings in review communities; third, this study proposes a new perspective pertaining to the relationship between reviewers’ identification and helpfulness evaluation.

The X-bar control chart with restriction of the capability indices

2017 ◽  
Vol 34 (1) ◽  
pp. 38-52 ◽  
Author(s):  
Pedro Carlos Oprime ◽  
Glauco Henrique de Sousa Mendes
Keyword(s):  
Phase I ◽  
Control Chart ◽  
Design Methodology ◽  
Simulation Method ◽  
Operating Conditions ◽  
Suggested Approach ◽  
Content Type ◽  
Capability Index ◽  
Simulation Techniques ◽  
Capability Indices

Purpose The purpose of this paper is to find the configuration of the number (m) and size (n) of the sample in Phase I that would make it possible to detect the out-of-control (OOC) state of the process with the smallest number of samples and ensure a capability index (Cpk) that would meet the customer’s requirements. Design/methodology/approach The suggested approach addresses this problem using simulation techniques and design of experiments (DOE). The simulation techniques made it possible to reproduce the normal operating conditions of the process. The DOE was used to construct a predictive model for control chart performance and thus to determine combinations of m and n in Phase I that would meet the capability objectives of the process. A numerical example and a simulation study were conducted to illustrate the proposed method. Findings Using simulation techniques and DOE, the authors can find the number (m) and size (n) of the sample in Phase I that would make it possible to detect the OOC state of the process with the smallest number of samples and ensure a Cpk that would meet the customer’s requirements. Originality/value In the real situations of many companies, choosing the numbers and sizes of samples (m and n) in Phases I and II is a crucial decision in relation to implementing a control chart. The paper shows that the simulation method and use of linear regression are effective alternatives because they are better known and more easily applied in industrial settings. Therefore, the need for alternatives to the X control chart comes into play.

Kinematic investigation and fatigue life analysis of angular contact ball bearing in wide speed range based on raceway friction

2020 ◽  
Vol 72 (7) ◽  
pp. 845-850
Author(s):  
Yue Liu
Keyword(s):  
Fatigue Life ◽  
Peer Review ◽  
High Speed ◽  
Ball Bearing ◽  
Operating Conditions ◽  
Angular Contact Ball Bearing ◽  
Content Type ◽  
Speed Range ◽  
Uniform Model ◽  
Wide Speed Range

Purpose The purpose of this paper is to clarify the relationship between fatigue life and kinematics of angular contact ball bearing. It proposes a new modeling method of spin to roll ratio based on raceway friction, which is more accurate than the traditional raceway control theory. Design/methodology/approach The uniform model of spin to roll ratio based on raceway friction in a wide speed range is proposed using quasi-statics method, which considers centrifugal force, gyroscopic moment, friction force of raceway and other influencing factors. The accuracy is considerably improved compared with the static model without increasing too much computation. Findings A uniform model for spin to roll ratio of angular contact ball bearing based on raceway friction is established, and quite different relationships between fatigue life and speed under two operating conditions are found. Research limitations/implications The conclusion of this paper is based on the bearing basic fatigue life calculation theory provided by ISO/TS 16281; however, the accuracy of theory needs to be further verified. Practical implications This paper provides guidance for applying angular contact ball bearing, especially at a high speed. Originality/value This paper reveals the changing trend of fatigue life of angular contact ball bearing with the speed under different loads. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0030

Research on optimization of spindle bearing preload based on the efficiency coefficient method

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pingping He ◽  
Feng Gao ◽  
Yan Li ◽  
Wenwu Wu ◽  
Dongya Zhang
Keyword(s):  
Peer Review ◽  
Temperature Rise ◽  
Operating Conditions ◽  
Axial Stiffness ◽  
Efficiency Coefficient ◽  
Content Type ◽  
Mechanical Coupling ◽  
Spindle Bearing ◽  
Bearing Preload ◽  
Coefficient Method

Purpose The purpose of this paper is to research on optimization of spindle bearing preload based on efficiency coefficient method and provide theoretical guidance for variable preload of intelligent spindle. Design/methodology/approach Based on an established thermo-mechanical coupling model of angular contact ball bearing with fix-position preload, temperature rise and axial stiffness of the bearing at different speeds and preload are analyzed, and life of the bearing is estimated by the improved L-P theory. The bearing temperature rise, axial stiffness and life data are standardized, and the preload is optimized by the efficiency coefficient method according to the requirements of operating conditions. Findings The optimized preload meets comprehensive requirements of the bearing temperature rise, axial stiffness and life under different operating conditions. Originality/value In the past studies, it is rarely reported that temperature rise, stiffness and life of the bearing under thermo-mechanical coupling effect are used as objective functions to optimize preload at different speeds. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0205/

Information activities as serious leisure within the fanfiction community

2017 ◽  
Vol 73 (5) ◽  
pp. 843-857 ◽  
Author(s):  
Heather Hill ◽  
Jen J.L. Pecoskie
Keyword(s):  
Peer Review ◽  
Design Methodology ◽  
Information Science ◽  
Library And Information Science ◽  
Serious Leisure ◽  
Significant Information ◽  
Cultural Products ◽  
Content Type ◽  
Digital Heritage ◽  
Practical Implications

Purpose Fanfiction communities are actively engaged in creating cultural products. These large online communities have created and developed conventions that guide their solutions to gathering and presenting their work. The purpose of this paper is to investigate those conventions looking for evidence of information-related pursuits as serious leisure (SL) (Stebbins, 2007). Design/methodology/approach A diverse collection of fanfiction publishing platforms, blogs, and associated websites were subject to a qualitative inductive analysis (Lincoln and Guba, 1985). Platforms included both generalist sites like Archive of Our Own and more focused sites such as Teen Wolf Fic Finder. Findings Findings show significant information-related activities around collecting, wayfinding, and organizing. Collecting centers on platform policies focused on scope. Wayfinding relates to peer review as well as various reference-like work including reader’s advisory, reference questioning, and the creation of pathfinders. Organizing looks to the unique organizational schema created and used by the fanfiction communities. Research limitations/implications The authors explore implications of these activities in reference to the fanfiction community and the library and information science (LIS) discipline. The fanfiction community is shifting out of an ephemeral existence and into one of a more permanent digital heritage. Fanfiction is an SL pursuit that also has much to offer for consideration to the LIS discipline. Practical implications With respect to the wayfinding and organizing conventions of fanfiction communities, these activities provide librarianship with the opportunity to consider traditional activities in new ways. Originality/value Fanfiction is a little studied phenomenon in SL and in LIS. This research provides connections to both areas.

An improved degraded adhesion model for wheel–rail under braking conditions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wenliang Zhu ◽  
Wenjian Zhu ◽  
Shubin Zheng ◽  
Na Wu
Keyword(s):  
Peer Review ◽  
Design Methodology ◽  
Content Type ◽  
Emergency Braking ◽  
Rail Vehicles ◽  
Time Simulation ◽  
Adhesion Model ◽  
Braking Force ◽  
Degraded Adhesion ◽  
Adhesion Condition

Purpose The purpose of this paper is to develop an improved adhesion model to better reproduce the low adhesion condition of the anti-skid control for rail vehicles under braking condition. Design/methodology/approach In view of the low adhesion characteristics for rail vehicles under braking conditions, the Polach adhesion model was improved based on the sliding power and sliding energy. The wheel–rail low adhesion model suitable for braking condition was given. The analysis of braking anti-skid control under emergency braking condition was carried out through the co-simulation, and compared with the test data; the effectiveness and practicability of the improved low adhesion model were verified. Findings The results showed that the improved adhesion model is simple and efficient and the parameters involved are less, and it can be directly applied to the real-time simulation of anti-skid control in the process of train braking. Originality/value This paper can provide a theoretical reference for the reasons of change and improvement of adhesion between wheel and rail caused by the adjustment of braking force under anti-skid control, which can fulfill a need to the study of sliding energy on the contact surface, the removal effect of pollutants on the wheel–rail surface and the improvement and recovery of adhesion caused. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0244/

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