bluuebunny/crossref_metadata_2025_split huggingface dataset:
Australian audit for the endoluminal repair of abdominal aortic aneurysm: The first 12 months
Authors: Boult Maggi , Babidge Wendy , Anderson John , Denton Michael , Fitridge Robert , Harris John , Lawrence‐Brown Michael , May James , Myers Kenneth , Maddern Guy 
Published: March 2003

Background: The Australian Safety and Efficacy Register for New Interventional Procedures – Surgical (ASERNIP‐S) was contracted by the Commonwealth Department of Health and Aged Care to audit the procedure of endoluminal repair of abdominal aortic aneurysm. The purpose of the audit was to examine the safety and efficacy of the endoluminal graft (ELG) and, where possible, compare it to the open procedure. The first 12 months of data collection has now been completed. An overview of these results and some of the problems associated with the establishment of this audit are given. Methods: The administrative infrastructure to support the audit is based at the ASERNIP‐S office in Adelaide. To achieve high compliance rates, regular contact was maintained with surgeons. A reference group of senior vascular surgeons was established to provide expert support to the audit. Results: By December 2000, ASERNIP‐S had collected data on approximately 85% of privately performed ELG procedures during the first year of the audit. The early mortality rate was 1.3% in the endoluminal group compared to 2.6% in the open group. The rate of procedural complications was 15% in both groups, but the percentage of systemic complications was higher following the open repair. Aneurysm size and the number of pre‐existing conditions had a statistically significant relationship to the variation in the number of complications for ELG patients. Conclusions: Good compliance has been obtained from vascular surgeons for submission of the operative data sets. ASERNIP‐S aims to follow this group of patients closely to assess the medium to long‐term durability of this procedure.
Ultrasound‐guided, high‐energy extracorporeal ­ shock‐wave treatment of symptomatic calcareous tendinopathy of the shoulder
Authors: Jakobeit Christian , Winiarski Barbara , Jakobeit Susanne , Welp Lars , Spelsberg Gerhard 
Published: March 2003

Background:  The objective of the present study was to test the effectiveness of ultrasound‐guided high‐energy extracorporeal shock‐wave treatment in symptomatic chronic calcareous tendinopathy of the shoulder rotator cuff, and to assess the morphology of the hydroxyapatite deposits before and after this treatment.Methods:  The study involved 80 patients who suffered from calcification of the rotator cuff. These patients were treated with an instrument with electromagnetic induction of shock‐waves (Doli‐Lithotripter, Dornier, Munich, Germany) under continuous ultrasound location of the treatment focus. The treatments were carried out in one to five sessions at an interval of 4−6 weeks. Each patient received a total of 1800 shock waves in each therapy. The flow density of the energy in the therapy focus was 0.08−0.42 mJ/mm2.Results:  Sixty‐eight patients (85%) attained complete freedom from symptoms or only had minimal residual symptoms when stressing their shoulder joint. The calcification suffered by 57 (71.2%) patients was completely resorbed after treatment and partially resorbed in 16 patients (20%). Complete resorption of the calcareous deposits led to freedom from symptoms. In all patients with amorphous calcareous deposits, there was complete resorption of the calcification. Mixed calcareous foci were eliminated in 64.7−77% of the cases, depending on the extent of amorphous structures. Complete resorption was achieved in 44.4% of patients where homogeneous calcareous deposits were >1 cm in size.Conclusion:  Shock‐wave treatment in periarthritis of the shoulder is a new and very effective method for symptomatic calcareous tendinopathy. Extracorporeal shock‐wave treatment has good prospects of success in any type of calcification. As a non‐invasive technique with a high success rate, shock‐wave treatment is an alternative to surgical operations in patients who remain symptomatic after exhaustive conservative treatment.
Elective resection and anastomosis for colorectal cancer: A prospective audit of mortality and morbidity 1976−1998
Authors: Killingback Mark , Barron Prudence , Dent Owen 
Published: March 2003

Background:  The purpose of this paper is to audit the morbidity and mortality for colorectal cancer after open elective resection and anastomosis by a single colorectal surgeon (MK), with reference to any differences between intraperitoneal (IPA) and extra­peritonealanastomoses (EPA).Methods:  The prospective documentation of postoperative complicationswas compiled by the surgeon, charge nurses and a research assistant (PB). The operations were performed in three hospitals between 1976 and 1998.Results:  Some 1392 consecutive patients were treated electively by 1418 resections with anastomosis. There were 23 postoperative deaths (1.6%). Significant adverse events, which were potentially avoidable, occurred in 10 (43.5%) of the patients who died. Themorbidity rate was 41.6%. Clinical anastomotic leaks occurred more frequently in EPA (27/581, 4.7%) than in IPA (2/827, 0.2%; P < 0.0001).Anastomotic leak caused the death of two patients (0.14%).Routine prophylactic anticoagulation did not decrease the incidenceof pulmonary embolism. Significant thrombophlebitis at the intravenous cannula site occurred in 54 patients (3.8%), wound infection in 29 (2.1%), and postural peripheral nerve injury in the upper limbs occurred in 11 patients (0.8%). Thirty‐eightpatients (2.7%) were returned to the operating theatre for 42 unscheduled operations.Conclusion:  Mortality associated with elective resection of colorectal cancer with anastomosis is principally related to age, cardio­vascular disease and avoidable adverse events. A wide range of complications may follow this type of surgery, especially after extra peritoneal operations. A classification of anastomotic leaks is suggested toassist in comparisons of this complication which remains a significant concern following extra peritoneal anastomoses.
Cholecystectomy for gall bladder dyskinesia: Symptom resolution and satisfaction in a rural surgical practice
Authors: Gall Carey Andrew , Chambers Kevin John 
Published: March 2003

Background:  Gall bladder dyskinesia describes a clinical entity with symptoms of biliary colic but without objective evidence of gallstones. Recent work has suggested laparoscopic cholecystectomy as an effective treatment although this approach has not gained widespread acceptance in Australia.Methods:  At the sole nuclear medicine facility in Mildura, Victoria, a retrospective search of patients with gallbladder ejection fractions ≤35% on CCK‐HIDA (cholecystokinin‐99mTc hepatoiminodiacetic acid) scanning over a 3‐year period from 1 January 1998 was undertaken. Twenty‐eight patients proceeded to cholecystectomy by the author and case notes were reviewed for symptoms, preoperative investigation, operation, pathology and complications. Telephone follow‐up was carried out assessing symptom response and overall satisfaction following operation.Results:  Follow up was achieved in 100% of patients with a mean duration of 18 months. Twenty‐five of 28 underwent chole­cystectomy by laparoscopic approach and there were no complications in the series. All gall bladders demonstrated an abnormality at histology. Overall, 79% of patients had some symptom improvement at follow‐up with 29% completely symptom free. Six patients (21%) were not improved following cholecystectomy. Overall satisfaction was high with a median 8/10.Conclusion:  Laparoscopic cholecystectomy is recommended for gallbladder dyskinesia diagnosed on CCK‐HIDA scanning, after other causes have been excluded and informed discussion regarding incomplete symptom resolution has been undertaken. Improvement without operation occurs only in the minority and is rarely complete. Cholecystectomy affords at least partial symptom relief in the majority with high levels of patient satisfaction.
Pancreatic abscess: 10 years experience
Authors: Srikanth G. , Sikora Sadiq S. , Baijal Sanjay S. , Ayyagiri Archana , Kumar Ashok , Saxena Rajan , Kapoor Vinay K. 
Published: March 2003

Background:  Secondary infections of pancreatic and peripancreatic necrosis account for most of the deaths following acute pancreatitis. These infections occur in the form of ‘infected pancreatic necrosis’ and ‘pancreatic abscess’. The latter is a rare complication of acute pancreatitis in comparison with the former.Methods:  Twenty‐one patients with pancreatic abscess were managed over a 10‐year period at a tertiary care centre in Northern India. The present report details the clinical profile, investigations performed and management strategy (surgery and intervention radiology) of these patients. The role of surgery and percutaneous catheter drainage (PCD) in the management of pancreatic abscess is discussed, with emphasis on the successful outcome seen in a properly selected group of patients managed by PCD.Results:  Of the 21 patients, 12 were managed by percutaneous intervention, nine were managed surgically (of these, two had a prior PCD) and two patients were managed conservatively. The overall mortality was 9.5% (2/21). Thus, percutaneous management was suitable for 57% patients, was successful in 83.3%, with a mortality of 8.3%. Surgical therapy alone was offered to 33% of patients, was successful in 85.7%, with a mortality of 14.2%. Complications were seen in four of the nine patients managed by percutaneous drainage alone and eight of the nine patients managed surgically.Conclusions:  Pancreatic abscess is a potentially lethal complication in patients recovering from acute pancreatitis. Early diagnosis and prompt intervention with careful selection of patients based on computed tomography imaging for surgical or percutaneous radio­logical management, is met with a successful outcome in a majority of patients. The roles of surgery and PCD are complementary.
AN EXPERIMENTAL INVESTIGATION OF THE GROWTH OF SMALL CORNER FATIGUE CRACKS IN ALUMINIUM 6061‐T651
Authors: Carlson  , Steadman  , Dancila  , Kardomateas  
Published: March 2003

Results of an experimental investigation of the fatigue growth of small corner cracks emanating from small flaws are presented. Growth‐arrest behaviour was observed, and increases in crack length during growth periods were of the order of the transverse grain size. For the test material, the corner crack front intersects, on average, only three–six grains in the small crack regime monitored, so only a small number of constrained, interior grains is encountered. It is suggested that the presence of partially constrained surface grains may contribute to the ‘anomalous’ growth behaviour which has been observed by a number of investigators.The crack growth histories of the test data presented exhibit considerable scatter. It is shown that a Student’s t‐test can be used to estimate confidence intervals in order to provide a measure of the observed scatter. The variation in confidence intervals in the transition from small to long fatigue crack growth is discussed.
A VIEW ON DUCTILE‐FRACTURE MODELLING
Authors: Thomason PF 
Published: March 2003

Theoretical models of ductile fracture are reviewed in terms of experimental results from metallurgical studies of ductile fracture in metals and alloys. It is shown that the plastic limit‐load model, which is based on a criterion of void coalescence by internal microscopic necking of the intervoid matrix, is fully consistent with scanning electron microscope (SEM) observations of both the ductile‐fracture surface and the microstructure immediately adjacent to the fracture surface. On the other hand, the dilational‐plastic models of ductile fracture, which are based on the dilational‐growth of spherical voids to some arbitrary critical void‐volume fraction, are inconsistent with the microstructural observations of ductile fracture. This inconsistency between the dilational‐plastic models and experimental results is shown to be the combined effect of neglecting the controlling influence of extensional void‐growth and the failure to incorporate a physically realistic criterion of void coalescence.The problems of modelling the ductile crack‐growth process by both analytical and numerical (finite element) studies, where problems of uniqueness of the plastic velocity field may occur, are also considered. The limitations of the finite‐element method in modelling void‐coalescence problems, where the equations of plasticity are of second‐order hyperbolic form, are also discussed.
Statistical analysis and reliability prediction with short fatigue crack data
Authors: Wilson S.P. , Taylor D. 
Published: March 2003

ABSTRACTThis paper proposes a probability model to describe the growth of short fatigue cracks. The model defines the length of each crack in a specimen as a random quantity, which is a function of randomly varying local properties of the material microstructure. Once the model has been described, the paper addresses two questions: first, statistical inference, i.e. the fitting of the model parameters to data on crack lengths; and secondly, predicting the future behaviour of observed cracks or cracks in a new specimen. By defining failure of a specimen to be the time at which the largest crack exceeds a certain length, the solution to the prediction problem can be used to calculate a probability that the specimen has failed at any future time.The probability model for crack lengths is called a population model, and the statistical inference uses the ideas of Bayesian statistics. Both these concepts are described. With a population model, the solution to statistical inference and prediction requires quite complicated Monte Carlo simulation techniques, which are also described.
Deformation behaviour at the tip of a physically short fatigue crack due to a single overload
Authors: Hammouda  , Ahmad  , Sherbini  , Sallam  
Published: March 2003

ABSTRACTA two‐dimensional elastic–plastic finite element analysis was utilized to investigate the transition behaviour of a physically short fatigue crack following the application of a single overload cycle. The deformation accommodated at the tip of a crack artificially advancing with a fully reversed load was considered. The development of the cyclic crack tip opening displacement was computed and then modelled to include the effects of the stress level of the base cycles, overload pattern and crack length at which the transient cycle was applied.The cyclic crack tip opening displacement was initially of a relatively high value. It decreased and then increased to match the behaviour under the base load cycles. The extent and location of both the minimum and matching points were dependent on the overload crack length and the stress compared with the material’s yield stress. In the case of the yield stress being exceeded by the overload, the minimum and the‐return‐to‐normality points are identical.A previously developed crack tip deformation parameter was invoked to predict relevant experimental fatigue growth rates of short cracks reported in the literature.
Modelling the effect of creep–fatigue interaction on crack growth
Authors: Grover  , Saxena  
Published: March 2003

AbstractTime‐dependent creep–fatigue crack growth (CFCG) is a major consideration in estimating the remaining life of elevated temperature components. Fracture mechanics approaches have proven useful in providing a framework for characterizing crack growth under service conditions, and in defining safe operating conditions and selecting inspection criteria and intervals. Experimental and analytical approaches have been developed to characterize crack growth under combined creep and fatigue loading conditions using (Ct )avgas the crack tip parameter. The analytical approaches that have been proposed to characterize CFCG are limited in their application because they do not completely account for the effect of creep–fatigue interactions in modelling crack tip deformation, and thus, accurately estimating the (Ct )avgvalue. A new creep‐reversal parameter,CR , is defined in this study to quantify the extent of creep–fatigue interaction at the crack tip, and is used in an analytical scheme, suitable for components, for calculating (Ct )avg . This approach does not rely on any simplifying assumptions regarding the extent of reinstatement ofCt , which is dependent on the amount of creep reversal due to cyclic plasticity, during the unloading part of a trapezoidal loading waveform cycle. The (Ct )avgvalues calculated by this approach compare well with the experimentally obtained values for compact type (CT) specimens, thus providing an experimental verification of the approach.
The fatigue limit and its elimination
Authors: Miller  , O’donnell  
Published: March 2003

The classical fatigue limit of ferrous metals is a consequence of testing materials at a constant range of cyclic stress and determining the cyclic stress range below which fatigue failures do not occur. This classical fatigue limit of a material is equated to the condition for which fatigue cracks can not propagate beyond microstructural barriers.This paper discusses the causes leading to the elimination of this fatigue limit, including the introduction of transitory cyclic‐dependent mechanisms and time‐dependent processes that will permit a previously non‐propagating crack to grow across the different threshold states expressed in terms of linear‐elastic fracture mechanics (LEFM), elastic–plastic fracture mechanics (EPFM) and microstructural fracture mechanics (MFM).These transitory mechanisms and processes include different loading and environmental conditions, which in a long‐life engineering plant (e.g. 30 years lifetime) can lead to apparently premature failures. Of greater concern is the creation of a new crack‐initiation zone, i.e. a transfer from a surface‐generated crack to an internal‐generated crack that eventually dominates the fatigue failure event.The impact of these conditions on the elimination of the classical fatigue limit necessitates changes in Design Codes of Practice, and such changes are discussed in relation to the extremely long‐lifetime regime (107 < Nf < 1012 cycles‐to‐failure) which is increasingly applicable to the modern day engineering plant.
Effects of a single tensile overload on fatigue crack growth in a 316L steel
Authors: Wheatley  , Hu  , Estrin  
Published: March 2003

ABSTRACTThe aim of this study was to investigate the effects of a single tensile overload on subsequent fatigue crack growth in a 316L stainless steel. Fatigue tests were conducted under the plane stress condition, and further supplemented with compliance measurements and field emission scanning electron microscopy (FESEM) observations. Effects of a tensile overload, e.g. initial acceleration and subsequent retardation of fatigue crack growth, were explained and quantified by FESEM and compliance measurements. The FESEM observations suggest that the initial crack growth acceleration stems from void and quasi‐cleavage fracture within the fatigue damage zone in the vicinity of the crack tip. Systematic compliance measurements taken during fatigue crack growth suggest that the overall crack growth retardation is related to strain hardening and residual compressive stress produced by the plastic deformation associated with the tensile overload.
Influence of pitting on the fatigue life of a turbine blade steel
Authors: Zhou  , Turnbull  
Published: March 2003

ABSTRACTThe role of pits as stress raisers and their influence on fatigue life has been investigated for a 12Cr turbine blade material. A particular feature of this work was the establishment of an electrochemical procedure for generating pits with ‘controlled’ pit depth and low density.Pits grown under laboratory conditions were partially spherical in shape and simulated, in general appearance, those observed in service. In terms of the threshold stress intensity factor, the results supported the concept of pits acting as effective cracks of the same depth, provided that a short crack model based on an effective crack length is used.
A low‐cycle fatigue life prediction model of ultrafine‐grained metals
Authors: DING H.‐Z. , MUGHRABI H. , HÖPPEL H. W. 
Published: March 2003

ABSTRACTA (high strain) low‐cycle fatigue (LCF) life prediction model of ultrafine‐grained (UFG) metals has been proposed. The microstructure of a UFG metal is treated as a two‐phase ‘composite’ consisting of the ‘soft’ matrix (all the grain interiors) and the ‘hard’ reinforcement (all the grain boundaries). The dislocation strengthening of the grain interiors is considered as the major strengthening mechanism in the case of UFG metals. The proposed model is based upon the assumption that there is a fatigue‐damaged zone ahead of the crack tip within which the actual degradation of the UFG metal takes place. In high‐strain LCF conditions, the fatigue‐damaged zone is described as the region in which the local cyclic stress level approaches the ultimate tensile strength of the UFG metal, with the plastic strain localization caused by a dislocation sliding‐off process within it. The fatigue crack growth rate is directly correlated to the range of the crack‐tip opening displacement. The empirical Coffin–Manson and Basquin relationships are derived theoretically and compared with experimental fatigue data obtained on UFG copper (99.99%) at room temperature under both strain and stress control. Good agreement is found between the model and the experimental data. It is remarkable that, although the model is essentially formulated for high strains (LCF), it is also found to be applicable at low strains in the high‐cycle fatigue (HCF) regime.
A quantitative model for predicting the morphology of surface initiated rolling contact fatigue cracks in back‐up roll steels
Authors: FROLISH M. F. , FLETCHER D. I. , BEYNON J. H. 
Published: March 2003

ABSTRACT A previously presented qualitative model for the rolling contact fatigue and spalling failure of back‐up rolls has been quantified in terms of crack lengths and growth directions. The morphologies of surface initiated fatigue cracks have been predicted using published data on the mode I and mode II thresholds in low carbon and roll steels, respectively, and the theoretical determination of the mode I and mode II stress intensity factors at the tips of the inclined surface cracks. The predictions have been validated by using the results of the metallographic examination of rolling contact fatigue cracks produced in test discs used in experimental simulations and the examination of spalled material from a back‐up roll.
On the fitting and extrapolation ofJ‐resistance data derived through the linear normalization technique
Authors: TARPANI J. R. , BOSE FILHO W. W. , SPINELLI D. 
Published: March 2003

ABSTRACTIn this paper, an assessment is made regarding the effects ofJ–Rcurve fitting and extrapolation methods in twoJ‐integral criteria – namely crack initiation,Ji, and tearing instability,J50– which were obtained through the linear normalization technique. Power‐law, logarithmic and linear fits were concurrently applied toJ–Δadata derived from sub‐sized compact tensile specimens machined from a nuclear grade steel and tested at 300 °C. Research results show that the logarithmicJ–Rfit is the most conservative approach within a broad range of elastic–plastic fracture resistance, compared to the conventional power‐law fit. On the other hand, the linear fitting method provided the most non‐conservativeJ‐predictions. The values ofJiandJ50have been successfully correlated with the net energy absorbed during Charpy impact testing of the materials.