Acoustic Diagnostics of Electrical Origin Fault Modes with Readily Available Consumer-Grade Sensors

Acoustic diagnostics, traditionally associated with mechanical fault modes, can potentially solve a wider range of monitoring applications. Typically, fault modes are induced purposefully by the researcher through physical component damage whilst the system is shutdown. This paper presents low-cost real-time fault diagnostics of a previously unreported acute electrical origin fault that manifests sporadically during system operation with no triggering intervention. A suitability study into acoustic measurements from readily available consumer-grade sensors for low-cost real-time diagnostics of audible faults, and a brief overview of the theory and configuration of the wavelet packet transform (including optimal wavelet selection methods) and empirical mode decomposition processing algorithms is also included. The example electrical origin fault studied here is an unpredictable current instability arising with the PWM-controller of a BrushLess DC motor. Experimental trials positively detect 99.9 % of the 1160 resultant high-bandwidth torque transients using acoustic measurements from a USB microphone and a smartphone. While the use of acoustic techniques for detecting emerging electrical origin faults remains largely unexplored, the techniques demonstrated here can be readily adopted for the prevention of catastrophic failure of drive and power electronic components

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

Acoustic emission A brief introduction to some of its uses in the aero engine industry

SIGLELD:8019.3153(PNR--90172) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Identifying fatigue crack growth by AE analysis

SIGLELD:8019.3153(PNR--90075). / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Protein supplementation and growth enhancer strategies in successive years to maximise growth of Brahman cross steers grazing sown grass pastures on brigalow lands

A strategy comprising a winter/spring protein supplement, rumen modifier and hormonal growth promotant (Compudose 400) was used in either the first year (Tl), second year (T2), or in both years (T1+2) following weaning in Brahman cross steers as a means of increasing liveweight gain up to 2.5 years of age. T2 produced the heaviest final liveweight (544.7 kg) and highest overall liveweight gain (366.7 kg), but these were not significantly different from T1 (538.6 kg; 360.9 kg), or T1+2 (528.7 kg; 349.3 kg). However, final liveweight and overall liveweight gains of T1 and T2 but not T1+2 were significantly greater than for untreated (C) steers (504.9 kg; 325.2 kg, both P < 0.05). Regardless of the strategy imposed, liveweight and liveweight gain were enhanced, however final liveweights in each treatment were below the preferred minimum target liveweight (570-580 kg) for premium export markets. Treatment in both years gave no benefit over treatment in 1 year only. 19th Biennial Conference. 5-9 July 1992. LaTrobe University, Melbourne

Causes of rejection of beef bulls in breeding soundness evaluation

The objective of this study was to analyze the rates of rejection in the different steps of the breeding soundness evaluation of beef bulls in the state of Rio Grande do Sul, Brazil. The breeding soundness of 22,113 young and mature bulls of 14 beef breeds, participating in the Program of Reproductive Evaluation (PARTO) was evaluated in the experiment. Data concerning to the causes of rejection in the four steps of the breeding soundness evaluation (general physical examination, genital tract examination, semen evaluation and sexual behavior assessment) were analyzed by the Chi-square test and univariate regression analysis. According to year, general physical examination, genital tract examination and semen evaluation determined the rejection of 0.9% to 2.5%, 5.1% to 7.7%, 1.8% to 5.3%; and 4.2% to 6.7%, 7.3 to 9.3%, and 2.5% to 5.5% of young and mature bulls, respectively. Mature bulls presented higher chances of rejection than young bulls in the general physical examination in every year evaluated; as to the genital tract examination, their chances of rejection were higher in years I and II, but not in year III. In the semen evaluation, there was no difference between the ages assessed in any of the three years evaluated. Sexual behavior assessment accounted for the rejection of 1.9 to 6.0% of the young bulls and 2.9% to 3.9% of mature bulls, in accordance with the years evaluated; in years I and II, mature bulls presented higher rejection rates than young bulls. These results confirm the importance of performing all steps of the breeding soundness evaluation, including the sexual behavior assessment as a work routine, rather than an additional, optional stage of the evaluation, which should be carried out before the breeding season. The results indicate the relationship between bull age and rejection rate in the breeding soundness evaluation