scholarly journals Computer Simulation/Prediction of Wear in Mechanical Components

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Saad M. S. Mukras
Keyword(s):  
Computer Simulation ◽  
Piston Ring ◽  
State Of The Art ◽  
Contact Analysis ◽  
Cam Follower ◽  
Recent Developments ◽  
Cylinder Piston ◽  
Mechanical Components ◽  
Research Studies

In this paper, a state of the art on computer simulation and prediction of wear in mechanical components is reviewed. Past and recent developments as well as approaches employed in the simulation and prediction of wear are reviewed. In particular, the wear models, contact analysis schemes, and wear evolution prediction procedures as well as their application to the mechanical components (including cam-follower, gears, bearings, and cylinder/piston/piston ring wear) are reviewed. Recommendations and suggestions on possible directions for further research studies are also presented.

Some Recent Developments in Sewage Sludge Pumping

1988 ◽  
Vol 20 (4-5) ◽  
pp. 227-236
Author(s):  
J. H. Lohmann ◽  
W. F. Garber
Keyword(s):  
Sewage Sludge ◽  
Treatment Plant ◽  
Rheological Characteristics ◽  
Volatile Content ◽  
Collection System ◽  
Positive Displacement ◽  
Low Viscosity ◽  
Recent Developments ◽  
Cylinder Piston ◽  
Pumping Equipment

The pumping of sewage sludge solids is reviewed in terms of handling high and low viscosity materials with solids concentrations varying from about 4 % to perhaps 50 %. Knowledge of rheological characteristics including thixotropy is necessary in designing pumping systems with sludge solids percentages, volatile content, particle size, abrasives content and temperatures being variables which could change pump types found suitable from facility to facility. The characteristics of a sewage collection system is also important in determining pumping parameters needed in a treatment plant. Solids handling equipment from other industries have made significant contributions to sewage solids pumping in recent years. Included are moyno-type progressing cavity screw-centrifugal, recessed impeller rotation piston positive displacement, and two cylinder piston S-transfer positive displacement pumps. Pumping equipment used in the F.R.G. and in Southern California in the U.S.A. is remarkably similar. These types of pumps offer the possibility of designing optimum solids dewatering and transfer systems.

scholarly journals Recent Developments in Coatings, Gratings, and Reflective Components

1984 ◽  
Vol 79 ◽  
pp. 607-616
Author(s):  
R. R. Shannon
Keyword(s):  
State Of The Art ◽  
New Technology ◽  
The State ◽  
Current Technology ◽  
Large Size ◽  
Incoming Radiation ◽  
Recent Developments ◽  
Electronic Sensors ◽  
Large Primary ◽  
Telescope System

The requirements on gratings and coatings for astronomical use differ from the general industrial requirements primarily in the scale of the components to be fabricated. Telescopes have large primary mirrors which require large coating plants to handle the components. Dispersive elements are driven by the requirement to be efficient in the presence of large working apertures, and usually optimize to large size in order to efficiently use the incoming radiation. Beyond this, there is a “new” technology of direct electronic sensors that places specific limits upon the image scale that can be used at the output of a telescope system, whether direct imagery or spectrally divided imagery is to be examined. This paper will examine the state of the art in these areas and suggest some actions and decisions that will be required in order to apply current technology to the predicted range of large new telescopes.

Rewiew of Fracture and Fatigue in Ceramic Matrix Composites

2000 ◽  
Vol 53 (6) ◽  
pp. 147-174 ◽  
Author(s):  
Victor Birman ◽  
Larry W. Byrd
Keyword(s):  
High Temperature ◽  
State Of The Art ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Review Article ◽  
Successful Implementation ◽  
Matrix Composites ◽  
Recent Developments ◽  
Hostile Environments

A review of recent developments and state-of-the-art in research and understanding of damage and fatigue of ceramic matrix composites is presented. Both laminated as well as woven configurations are considered. The work on the effects of high temperature on fracture and fatigue of ceramic matrix composites is emphasized, because these materials are usually designed to operate in hostile environments. Based on a detailed discussion of the mechanisms of failure, the problems that have to be addressed for a successful implementation of ceramic matrix composites in design and practical operational structures are outlined. This review article includes 317 references.

A Single Technically Consistent Design Formula for the Thickness of Cylindrical Sections Under Internal Pressure

2006 ◽  
Vol 129 (1) ◽  
pp. 211-215 ◽  
Author(s):  
John D. Fishburn
Keyword(s):  
Experimental Data ◽  
Internal Pressure ◽  
State Of The Art ◽  
Original Data ◽  
Pressure Vessels ◽  
Time Dependent ◽  
Design Codes ◽  
Recent Developments ◽  
Current Design ◽  
Single Formula

Within the current design codes for boilers, piping, and pressure vessels, there are many different equations for the thickness of a cylindrical section under internal pressure. A reassessment of these various formulations, using the original data, is described together with more recent developments in the state of the art. A single formula, which can be demonstrated to retain the same design margin in both the time-dependent and time-independent regimes, is shown to give the best correlation with the experimental data and is proposed for consideration for inclusion in the design codes.

Website traffic measurement and rankings: competitive intelligence tools examination

2018 ◽  
Vol 14 (4) ◽  
pp. 423-437 ◽  
Author(s):  
David Prantl ◽  
Martin Prantl
Keyword(s):  
Design Methodology ◽  
State Of The Art ◽  
Competitive Intelligence ◽  
Data Sets ◽  
Traffic Data ◽  
Content Type ◽  
Traffic Measurement ◽  
Data Estimation ◽  
Research Studies

PurposeThe purpose of this paper is to examine and verify the competitive intelligence tools Alexa and SimilarWeb, which are broadly used for website traffic data estimation. Tested tools belong to the state of the art in this area.Design/methodology/approachThe authors use quantitative approach. Research was conducted on a sample of Czech websites for which there are accurate traffic data values, against which the other data sets (less accurate) provided by Alexa and SimilarWeb will be compared.FindingsThe results show that neither tool can accurately determine the ranking of websites on the internet. However, it is possible to approximately determine the significance of a particular website. These results are useful for another research studies which use data from Alexa or SimilarWeb. Moreover, the results show that it is still not possible to accurately estimate website traffic of any website in the world.Research limitations/implicationsThe limitation of the research lies in the fact that it was conducted solely in the Czech market.Originality/valueSignificant amount of research studies use data sets provided by Alexa and SimilarWeb. However, none of these research studies focus on the quality of the website traffic data acquired by Alexa or SimilarWeb, nor do any of them refer to other studies that would deal with this issue. Furthermore, authors describe approaches to measuring website traffic and based on the analysis, the possible usability of these methods is discussed.

scholarly journals The origins of pottery in East Asia: updated analysis (the 2015 state-of-the-art)

2015 ◽  
Vol 42 ◽  
Author(s):  
Yaroslav Kuzmin
Keyword(s):  
East Asia ◽  
South China ◽  
State Of The Art ◽  
Russian Far East ◽  
Critical Evaluation ◽  
Far East ◽  
Transbaikal Region ◽  
Recent Developments ◽  
Japanese Islands ◽  
The Russian Far East

Recent developments related to the emergence of pottery in East Asia and neighbouring regions are presented. According to a critical evaluation of the existing evidence, the oldest centres with pottery in East Asia are situated in South China (dated to c. 18 000 calBP), the Japanese Islands (c. 16 700 calBP), and the Russian Far East (c. 15 900 calBP). It is most likely that pottery-making appeared in these regions independently of each other. In Siberia, the earliest pottery now known isfrom the Transbaikal region (dated to c. 14 000 calBP). However, it did not influence the more westerly parts of Siberia in terms of the origin and spread of pottery-making.

Status of Centrifugal Impeller Internal Aerodynamics—Part II: Experiments and Influence of Viscosity

1980 ◽  
Vol 102 (3) ◽  
pp. 738-746 ◽  
Author(s):  
D. Adler
Keyword(s):  
Viscous Flow ◽  
Experimental Work ◽  
State Of The Art ◽  
Centrifugal Impeller ◽  
Future Research ◽  
Research Topics ◽  
Flow Problems ◽  
Recent Developments ◽  
Internal Aerodynamics ◽  
The Subject

Recent developments in internal viscous aerodynamics of centrifugal impellers and related flows are critically reviewed. The overall picture which emerges provides the reader with a state-of-the-art perspective on the subject. Gaps in understanding are identified to stimulate future research. Topics included in this review are: experimental work carried out in the last decade, the structure of turbulence in curved rotating passages and solution of viscous flow problems in impellers.

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