Spalling in rolling element bearing is a common localized defect generated during the operation of bearing due to rolling fatigue. Size estimation of such localized defect can be helpful in determining severity of the fault. This further can be used as an input for predicting the remaining useful life of the bearing. The popular approach for estimating the size (in terms of width) of spall is to trace the entry and exit events of rolling element while interacting with the fault. The time estimated between entry and exit of rolling element from pit like spall can be converted to the geometric estimation is the fault size from vibration signature. The present approach demonstrates the use of Singular Spectrum Analysis (SSA) to accomplish the task. The vibration signals generated from the interaction of rolling element with the localized fault is a hybrid signal consisting of low frequency stepped response generated while the rolling element enters the fault and is superimposed on to the high frequency impact generated during the reentry of the rolling element in to the raceway from the spall. The signal information is enhanced via preprocessing the signal with Total Variance Regularization (TVR) filtration. The informative signal, which is extracted from the row temporal signal via SSA, aids in the accurate identification of entry and exit events. The proposed method integrating TVR with SSA for faut size estimation is validated using simulated signals and experimental signals from independent resources. The result shows strong agreement with the accuracy level of size estimation.

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INTRODUCTION:Intestinal obstruction is frequently encountered in differential diagnosis of patients presenting with a acute abdomen. Even with an early diagnosis bowel obstruction still represent some of the most difficult problems that surgeons face with regard to optimal timing of therapy and appropriate management in different type of bowel obstruction. AIMS AND OBJECTIVES:To study the various modes of presentation, importance of early diagnosis and management of patients , the incidence of different complications during treatment and their management in tertiary care centre of urban population. MATERIALS AND METHODS:This study was conducted for a period of 2 years with patients admitted from 01/ 07/ 2017 up to 30/06/ 2019 with a sample size of 50 patients in L.G. hospital, Ahmedabad .Present study was prospective, observational, cross-sectional study. OBSERVATIONS AND DISCUSSION:Out of 50 patients, 70% were males and 30% were females, more commonly in young patients (11-20 yrs age). Most common presenting cause of intestinal obstruction is subacute intestinal obstruction which is 20 % and these cases were managed conservatively. Conservative approach was helpful in 38% of cases due to their early presentation and subacute type of obstruction most commonly. Primarily operative approach after initial resuscitation were 32% of total cases with indications like acute presentation with tenderness, abnormal peristalsis like absent or hyperperistalsis, fever, irreducible or palpable lump, ultrasonography finding of peritonitis etc. Most common complication encountered was wound infection 35% of operated cases. Mortality was 4 % occurrence in present study. CONCLUSION: Of the 50 cases of intestinal obstruction in our study adhesions and bands are the common cause to produce intestinal obstruction. Koch's abdomen is also increasingly encountered in etiology of intestinal obstruction as stricture and it is related to poor socioeconomic status of study population in present study. Hernia related obstruction were higher in early twentieth century but decreasing nowadays. It suggests that planned hernia repair can avoid this complication. With better understanding of etiology due to advanced diagnostic ailments mortality rate is decreasing.