Experimental Study and Analysis on Incipient Stage of Cavitation Erosion

2007 ◽  
Author(s):  
Jiadao Wang ◽  
Shihan Liu ◽  
Li Qin ◽  
Darong Chen
Keyword(s):  
Experimental Study ◽  
Wear Debris ◽  
Cavitation Erosion ◽  
Rotating Disk ◽  
Mechanical Action ◽  
Incipient Stage ◽  
Micro Particles ◽  
Analysis Technique ◽  
The One ◽  
Wear Debris Analysis

Cavitation erosion has been studied for over one hundred years, but its mechanism is still uncertain. It has been found in this research that the existence of micro particles is an important factor to induce cavitation erosion. Experiments in rotating disk equipment were performed, and there is no obvious damage on sample after 5 minutes test in deionzed water, while the one tested in deionzed water with 500nm particles is eroded. Wear debris analysis technique was applied to study the particulates formed in the experiments, and results showed that many debris several micro-meters in size were yielded, which agreed with the scale of the cavitation pits on the sample. It was demonstrated that the mechanical action induces the cavitation erosion.

Image based portable wear debris analysis tool

2015 ◽  
Vol 67 (4) ◽  
pp. 389-398 ◽  
Author(s):  
Muhammad Ali Khan ◽  
Ahmed Farooq Cheema ◽  
Sohaib Zia Khan ◽  
Shafiq-ur-Rehman Qureshi
Keyword(s):  
Real Time ◽  
Wear Debris ◽  
Machine Component ◽  
Analysis Tool ◽  
Content Type ◽  
Real Time Analysis ◽  
Distribution Shape ◽  
Basic Features ◽  
Health Diagnosis ◽  
Wear Debris Analysis

Purpose – The purpose of this paper is to show the development of an image processing-based portable equipment for an automatic wear debris analysis. It can analyze both the qualitative and quantitative features of machine wear debris: size, quantity, size distribution, shape, surface texture and material composition via color. Design/methodology/approach – It comprises hardware and software components which can take debris in near real-time from a machine oil sump and process it for features diagnosis. This processing provides the information of the basic features on the user screen which can further be used for machine component health diagnosis. Findings – The developed system has the capacity to replace the existing off-line methods due to its cost effectiveness and simplicity in operation. The system is able to analyze debris basic quantitative and qualitative features greater than 50 micron and less than 300 micron. Originality/value – Wear debris basic features analysis tool is developed and discussed. The portable and near real-time analysis offered by the discussed work can be more technically effective as compared to the existing off-line and online techniques.

Study on Fuzzy Cluster in the Model for Rapid Identification of NC Processing

2012 ◽  
Vol 522 ◽  
pp. 673-676
Author(s):  
Xi Li ◽  
Dan Feng Feng
Keyword(s):  
Experimental Study ◽  
Intelligent Control ◽  
Likelihood Function ◽  
Rapid Identification ◽  
Fuzzy Cluster ◽  
Identification Algorithm ◽  
Signal Identification ◽  
Dynamic Identification ◽  
The One ◽  
S Model

In this paper, a application of signal identification by using fuzzy cluster is studied Based on the one order T-S model, an algorithm for online establishment the nonlinear model between the servo current and cutting force is presented by fuzzy likelihood function to derive fuzzy cluster. Finally, the experimental study has been given. The result showed that it can be regarded as a good dynamic identification algorithm for intelligent control of NC processing.

Analysis of the Behaviour of Rolling Bearings in Contaminated Oil Using Some Condition Monitoring Techniques

2006 ◽  
Vol 220 (5) ◽  
pp. 447-453 ◽  
Author(s):  
T Akagaki ◽  
M Nakamura ◽  
T Monzen ◽  
M Kawabata
Keyword(s):  
Vibration Analysis ◽  
Wear Debris ◽  
Friction And Wear ◽  
Rolling Bearing ◽  
Rolling Bearings ◽  
Deep Groove ◽  
Deep Groove Ball Bearing ◽  
Observation Results ◽  
Wear Debris Analysis ◽  
Worn Surfaces

Friction and wear behaviours of rolling bearing in contaminated oil containing white-fused alumina particles were studied. The friction and wear processes were monitored using wear debris analysis, such as ferrography and spectrometric oil analysis program, and vibration analysis. Test bearing was a deep groove ball bearing (6002P5); Wear debris and worn surfaces of the bearing components were observed with a scanning electron microscope (SEM). It was found that the friction coefficient in the contaminated oil became lower by about 0.001 than that in the new oil for the large contaminants. The results of wear debris analysis showed that the large contaminants caused the high wear rate in the bearing. Three types of wear debris were commonly observed: thread-like debris, cutting chip debris, and plate-like debris. On the basis of the SEM observation results of the worn surfaces, wear mechanisms of these wear debris were discussed. The results of vibration analysis showed that the probability density function of vibration waveform was normal distribution in both the new and contaminated oils. In the contaminated oil, it changed depending on the contaminant size and the runtime, i.e. the progress of wear in the bearing. The result of wear debris analysis was related to that of vibration analysis and discussed.

Divergent theories, converging evidence: The constructional semantics of competing future constructions

2018 ◽  
Vol 6 (1) ◽  
pp. 91-114
Author(s):  
Stefan Hartmann
Keyword(s):  
Experimental Study ◽  
The Other ◽  
Temporal Distance ◽  
Corpus Study ◽  
Distant Future ◽  
Other Hand ◽  
Future Events ◽  
The One ◽  
Near Future ◽  
Lines Of Evidence

Abstract This paper investigates the alternation between two competing German future constructions, the werden + Infinitive construction and the futurate present, from a usage-based perspective. Two lines of evidence are combined: On the one hand, a pilot corpus study indicates that werden + Infinitive is more likely to be used for referring to distant-future events than to near-future events. However, syntactic factors seem to be at least as decisive as semantic ones for speakers’ choice between the two constructions. On the other hand, an experimental study taps into language users’ interpretation of sentences framed in one of the two constructions. It can be shown that the grammatical framing does not significantly affect participants’ estimates of the temporal distance of the events to which the stimuli sentences refer. This suggests that the meaning differences between the two constructions be more nuanced, e.g. pertaining to discourse-pragmatic functions.

scholarly journals An Improved Method for Discerning Broken Rotor Bar Fault and Load Oscillation in Induction Motors

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3130 ◽  
Author(s):  
Liling Sun ◽  
Boqiang Xu
Keyword(s):  
Spectral Analysis ◽  
Theoretical Basis ◽  
Induction Motors ◽  
The Other ◽  
Improved Method ◽  
Broken Rotor Bar ◽  
Signal Parameters ◽  
Analysis Technique ◽  
Novel Strategy ◽  
The One

A few methods for discerning broken rotor bar (BRB) fault and load oscillation in induction motors have been reported in the literature. However, they all perhaps inevitably fail in adverse cases in which these two phenomena are simultaneously present. To tackle this problem, an improved method for discerning BRB fault and load oscillation is proposed in this paper based on the following work. On the one hand, the theoretical basis is analytically extended to include such an adverse case, yielding some important findings on the spectra of the instantaneous reactive and active powers. A novel strategy is thus outlined to correctly discern BRB fault and load oscillation even when simultaneously present. On the other hand, Estimation of Signal Parameters via Rotational Invariance Technique (ESPRIT) is adopted as the spectral analysis technique to deal with the instantaneous reactive and active powers, yielding a certain improvement compared to the existing methods, adopting Fast Fourier Transform (FFT). Simulation and experimental results demonstrate that the proposed method can correctly discern BRB fault and load oscillation even when simultaneously present.

scholarly journals Edukasi Kesehatan Mengenai Praktik Cuci Tangan pada Guru sebagai Upaya Pencegahan Covid-19

2021 ◽  
Vol 6 (2) ◽  
pp. 894-902
Author(s):  
Bertakalswa Hermawati ◽  
Oktia Woro Kasmini Handayani ◽  
Dyah Sukendra Mahendrasari ◽  
Farah Azizah Mukti ◽  
Aprilia Wijayanti
Keyword(s):  
Experimental Study ◽  
Check List ◽  
Rank Tests ◽  
Purposive Sampling ◽  
Quasi Experimental ◽  
The One

Kasus Covid-19 semakin meningkat namun praktik mencuci tangan dengan benar belum diterapkan sebagai upaya pencegahan. Tujuan penelitian ini adalah untuk meningkatkan praktik mencuci tangan pada guru anak usia dini. Penelitian ini menggunakan pendekatan kualitatif dan kuantitatif dengan  a quasi‑experimental study dan The One-Group Pretest-Posttest Design. Pengambilan sampel secara purposif (Purposive Sampling) yakni 15 guru di taman kanak-kanak di kelurahan Petompon, kota Semarang, Jawa Tengah, Indonesia. Instrumen penelitian ini adalah observasi dengan check list prosedur mencuci tangan sebelum dan sesudah intervensi. Metode yang digunakan adalah ceramah, diskusi, demonstrasi dan simulasi serta menggunakan media promosi yakni film dan leaflet. Data dianalisa dengan Wilcoxon Rank tests. Hasil penelitian membuktikan ada peningkatan praktik mencuci tangan secara signifikan setelah diberikan intervensi dibandingkan sebelum diberikan intervensi (p=0.001 0.05). Metode dan media promosi kesehatan efektif meningkatkan praktik cuci tangan pada guru anak usia dini

scholarly journals METODE MENGAJAR DAN MOTIVASI TERHADAP HASIL BELAJAR KETERAMPILAN SERVIS FLATTENIS LAPANGAN(STUDI EKSPERIMEN PADA MAHASISWA FIK UNM MAKASSAR)

2020 ◽  
Vol 12 (1) ◽  
pp. 21
Author(s):  
Hasbunallah AS ◽  
Ahmad Rum Bismar
Keyword(s):  
Experimental Study ◽  
Learning Outcomes ◽  
Teaching Methods ◽  
Design Method ◽  
Learning Motivation ◽  
High Learning ◽  
Significance Level ◽  
Analysis Technique ◽  
Lower Effect ◽  
Academic Year

The aim of this experimental study was todetermine the effect of all teaching methods, part, mixed and motivation result learning toward of flat service skill courts tennis. Learning motivation is divided into two parts, namely high andlow.This research was conducted at Faculty of Sport ScienceState University of Macassar,the academic year 2014/2015. Experimental using factorial design method 2x3. The sample consisted of 60 students were divided into 6 groups, each consisting of 10 students. Data analysis technique is a two-way analysis of variance (ANOVA) followed by Tukey's test at a significance level of α= 0.05. The results of this study indicate that ( (1) overall teaching methods higher effect of the part teacing methods on learning outcomes flat tennis service skills (2) overall teaching methods lower effect of the part teacing methods on learning outcomes flat tennis service skills, (3) overall teaching methods lower effect of the part teacing methods on learning outcomes flat tennis service skills,(4) there is interaction between the overall teaching methods, part teaching methods and combined teaching methods and learning motivation outcomes flat tennis service skills,(5) overall teaching methods higher effect of the part teacing methods on learning outcomes flat tennis service skillsusing a high learning motivation, (6) overall teaching methods lower effect of the part teacing methods on learning outcomes flat tennis service skillsusing a high learning motivation, (7) part teaching methods lower effect of the combined teacing methods on learning outcomes flat tennis service skillsusing a high learning motivation, (8) overall teaching methods higher effect of the part teacing methods on learning outcomes flat tennis service skillsusing a low learning motivation, (9) overall teaching methods lower effect of the part teacing methods on learning outcomes flat tennis service skillsusing a low learning motivation, (10) part teaching methods lower effect of the combined teacing methods on learning outcomes flat tennis service skillsusing a low learning motivation.

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