bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the dwell angle of split injection in a single-cylinder optical diesel engine
Authors: Díez Á , Zhao H 
Published: April 2010

This study investigates the effects of split-injection strategies with high levels of exhaust gas recirculation on the combustion performance and emissions in a single-cylinder direct-injection optical diesel engine. The engine is equipped with high-pressure common-rail fuel injection and designed to provide optical access through the piston window and side windows. The experiments were carried out at a relatively high engine speed of 2000r/min for an optical engine and in-cylinder conditions matched to a multiple-cylinder engine through boost and intake charge heating. High-speed combustion imaging, two-colour temperature, and soot concentration measurements were carried out in conjunction with in-cylinder pressure and heat release analysis and exhaust emissions. The results at two dwell angles and different injection timings are presented and analysed in this paper. The effects of the dwell angle and fuel injection timings on fuel air mixing, combustion, soot formation, and emission are identified and discussed.
Numerical and experimental research of stall inception on subsonic axial-flow compressor rotor
Authors: Lu J-L , Chu W , Peng K 
Published: April 2010

Three-dimensional flow simulation and blade tip high-response static pressure measurements were performed on an isolated subsonic compressor rotor to gain more insight into the stall inception mechanism of the compressors. The Navier—Stokes solver, EURANUS, was used for computation. The steady-state flow solution was achieved at the convergence of a four-stage explicit Runge—Kutta integration scheme. The time-dependent calculation was implemented in the implicit dual time stepping scheme, which allowed for the solution of a steady-state problem at each physical time step. The high-response static pressure was measured using five Kulite sensors installed on the casing. The data acquisition frequency was 100 kHz. The recorded data were later analysed using wavelet analysis method. Correlating the simulation result and the measurement result, it was shown that as the compressor was approaching the near stall (NS) condition, the tip leakage vortex dissipation and shedding became violent. The shedding or dissipated flow structures would consequently scatter around the blade tip passage, which formed the initial onset of stall disturbances. These scattered vortexes would finally lead to compressor stall as they hit and merge with each other into low-frequency disturbance of significant size and energy. A stall pre-alarming method based on the monitoring of the low-frequency spectrum power at the NS condition was also suggested by this study.
Fourier transform infrared and ultraviolet-visible investigation of swift heavy 100 MeV Ag-ion- and 75 MeV oxygen-ion-irradiated polyvinylidene fluoride thin films
Authors: Rana D S , Chaturvedi D K , Quamara J K 
Published: April 2010

Polyvinylidene fluoride (PVDF) polymer films (9, 12, and 20 μm) were irradiated with 100 MeV Ag ion (fluence: 1.875×1011 ions/cm2) and 75 MeV oxygen ion (fluences: 5.625×1011 and 5.675×1012 ions/cm2) using the PELLETRON facility at the Inter University Accelerator Centre, New Delhi, to study swift heavy ion (SHI) irradiation effects in thin films. The change in chemical, optical, and structural properties was analysed by comparing Fourier transform infrared (FTIR) and ultraviolet (UV)-visible spectra of pristine and irradiated films. The FTIR spectra show no major change in characteristic bands on irradiation, except that some weak bands appear because of the evolution of volatile species, unsaturated bond formation, decomposition of the free radicals, and subsequent cross-linking. The spectra of the irradiated films show some broadening and a decrease in intensity in characteristic bands when compared with the pristine samples. The FTIR results indicate that the overall chemical structure of PVDF is stable under SHI irradiation. The UV-visible absorption spectra of irradiated samples reveal hyperchromic shift, bathochromic shift, and hypsochromic shift. The spectra also estimate the direct optical band gap around 3.6 eV. The band gap decreases on irradiation, and the decrease is dependent on ion beam and fluence rate. The present study opens up the scope for the applicability of SHI-irradiated PVDF thin films as microsensors and actuators.
An assessment of steering drift during braking: A comparison between finite-element and rigid body analyses
Authors: Mirza N , Hussain K , Day A J , Klaps J 
Published: April 2010

A vehicle that deviates laterally from its intended path of travel when the brakes are applied is considered to demonstrate ‘instability’ in the form of an unexpected and undesirable response to the driver input. Even where the magnitude of lateral displacement of the vehicle is small (i.e. ‘drift’ rather than ‘pull’) such a condition would be considered unacceptable by manufacturers and customers. Steering ‘drift’ during braking can be caused by several factors, some of which relate to vehicle design and others to external influences such as road conditions. The study presented here examines the causes and effects of steering drift during straight-line braking. A comparative analysis is made between two types of vehicle model: one built with rigid suspension components and the other with flexible components. In both the cases, the vehicle behaviour is simulated during braking in a straight line, and responses including lateral acceleration, yaw rate, and lateral displacement of the vehicle are predicted and analysed under fixed steering control. Suspension/steering geometry characteristics, namely toe steer and caster angle, have been studied to understand how the effect of variations in these parameters differs in models with rigid or flexi-ble components drift during straight-line braking. Results from both vehicle models show that differences between rigid and flexible components can affect the predicted steering drift propensity. The differences between the two models have emphasized the importance of using flexible (compliant) components in vehicle handling simulations to achieve better correlation between prediction and experiment.
A quasi-static state examination of handle forces and translational acceleration at impending planar motion for the four-caster manually manoeuvred vehicle
Authors: Abraham B B , Johnson G R 
Published: April 2010

Motion resistance, handle forces, and translational acceleration of a four-caster manually manoeuvred vehicle (FMV) are examined at impending planar motion. FMV-wheel angular acceleration directions occur in polygon regions of the FMV-body translational acceleration. The mass centre force and torque, which balance motion resistance, using a Coulomb model, are non-linear and discontinuous functions of FMV-body acceleration. The transformation from mass centre force and torque to a dynamically equivalent handle-force measure is examined. A reference manoeuvre with a single set of caster orientations shows that FMV-body translational acceleration has a substantial effect on handle-force measure variation: an almost three-fold variation exists. The reference manoeuvre analysis is repeated with a representative sample of all caster orientations. The mean handle-force measure for this sample also shows a substantial handle-force measure variation, e.g. relatively high handle forces occur when the translational acceleration is directed as the impending change of FMV heading. This effect is independent of motion resistance values. As the handle forces required to balance motion resistance vary substantially depending on FMV-body translational acceleration, spatial constraints may have a substantial effect on handle forces. A relationship between handle forces and spatial constraints indicates that architectural planning has health and safety implications for the FMV operator.
Negotiating care: patient tactics at an urban South African hospital
Authors: Schneider Helen , le Marcis Frederic , Grard Julien , Penn-Kekana Loveday , Blaauw Duane , Fassin Didier 
Published: April 2010

Objectives: To examine the various ways in which patients sought to influence the care they received in the admission and adult medical services of a large urban, academic hospital in South Africa. These included the steps taken by patients to increase their access to services and improve their experience of care. Methods: Part of a qualitative study of rationing behaviour, the methods combined, observations, interviews and a survey. Results: Patient's actions were oriented to two main goals: obtaining care and preserving their sense of self and dignity. These actions shaped patients’ pathways in five key ways: meeting the entry criteria for admission; presenting as a cooperative, expert patient; mobilizing social networks among health care staff; making use of complaints mechanisms; and deploying narratives of resistance. Conclusions: Patients made tactical use of small spaces at the margins of the health care system. Although, with some exceptions, they had limited impact on the care received in the hospital, they highlight patients as active players and point to the ways in which patient agency can be strengthened in the light of the shift towards chronic disease care and greater patient involvement in care.
Scrub typhus: an unrecognized threat in South India – clinical profile and predictors of mortality
Authors: Chrispal Anugrah , Boorugu Harikishan , Gopinath Kango Gopal , Prakash John Antony Jude , Chandy Sara , Abraham O C , Abraham Asha Mary , Thomas Kurien 
Published: April 2010

Summary Scrub typhus is an important cause of acute undifferentiated febrile illnesses in the Indian subcontinent. Delay in diagnosis and in the initiation of appropriate treatment can result in severe complications such as acute respiratory distress syndrome (ARDS), septic shock and multisystem organ failure culminating in death. We conducted a prospective, observational study to delineate the clinical profile and predictors of mortality in scrub typhus in adults admitted to the medical wards of a tertiary care, referral hospital in South India over a one-year period. The case fatality rate in this study was 12.2%. Metabolic acidosis (odds ratio [OR] 6.1), ARDS (OR 3.6), altered sensorium (OR 3.6) and shock (OR 3.1) were independent predictors of mortality. It appears that scrub typhus has four possible overlapping clinical presentations: mild disease; respiratory predominant disease; central nervous system predominant disease (meningoencephalitis); or sepsis syndrome. Given the telltale presence of an eschar (evident in 45.5%), the characteristic clinical profile and the dramatic therapeutic response to a cheap, yet effective, drug such as doxycycline, medical practitioners in the region should have ample opportunity to reach an early diagnosis and initiate treatment which could, potentially, reduce the mortality and morbidity associated with scrub typhus.
One-stage tubeless antegrade ureteric stenting: a safe and cost-effective option?
Authors: Chitale Sudhanshu , Raja Vaiyapuri , Hussain Nabeel , Saada Janak , Girling Simon , Irving Stuart , Cockburn JF 
Published: April 2010

INTRODUCTIONAntegrade insertion of ureteric stent has become an established mode of management of upper tract obstruction secondary to ureteric pathology. It is conventionally performed as a two-stage procedure for various reasons but, more recently, a one-stage approach has been adopted.PATIENTS AND METHODSWe discuss our experience of primary one-stage insertion of antegrade ureteric stent as a safe and cost-effective option for the management of these difficult cases in this retrospective observational case cohort study of patients referred to a radiology department for decompression of obstructed upper tracts. Data were retrieved from case notes and a radiology database for patients undergoing one-stage and two-stage antegrade stenting. It was followed by telephone survey of regional centres about the prevalent local practice for antegrade stenting. Outcome measures like hospital stay, procedural costs, requirement of analgesia/antimicrobials and complication rates were compared for the two approaches.RESULTSa one-stage approach was found to be suitable in most cases with many advantages over the two-stage approach with comparable or better outcomes at lower costs. Some of the limitations of the study were retrospective data collection, more than one radiologist performing stenting procedures and non-availability of interventional radiologist falsely raising the incidence of two-stage procedures.CONCLUSIONSIn the absence of any clinical contra-indications and subject to availability of an interventional radiologist’s support, one-stage antegrade stenting could easily be adopted as a routine approach for the management of benign or malignant ureteric obstruction.
Understanding of intra-operative tourniquets amongst orthopaedic surgeons and theatre staff – a questionnaire study
Authors: Sadri Amir , Braithwaite Ian J , Abdul-Jabar Hani B , Sarraf Khaled M 
Published: April 2010

INTRODUCTION Pneumatic tourniquets are used frequently in orthopaedic theatres to provide a bloodless field whilst operating on the extremities. Their use has given rise to complications and preventable damage due to over-pressurisation and prolonged application. We designed a questionnaire to assess the knowledge on tourniquet use among operating department assistants (ODAs) and specialist registrars (SpRs) in orthopaedic surgery. SUBJECTS AND METHODS A questionnaire was constructed using set guidelines from the Association of periOperative Registered Nurses (AORN) for recommended practice of tourniquet application. This was distributed to orthopaedic registrars with varying levels of experience and ODAs from five different NHS hospitals. The unpaired, two tailed t-test was used to test for statistical significance of results. RESULTS A total of 54 completed questionnaires were collected for analysis. The study population included 29 orthopaedic SpRs and 25 ODAs. The mean score for the orthopaedic SpRs as a group was 41.3% (SD 6.85; range, 29.0–54.8%). The mean score for the ODAs was 46.7% (SD 9.64; range, 23.3–62.9%) with a P-value of 0.024. CONCLUSIONS Most surgeons are taught how to use pneumatic tourniquets by their senior colleagues as no formal teaching is given. Most of the complications are infrequent and preventable. However, their consequences can be devastating to the patient with medicolegal implications. Our results show suboptimal knowledge of tourniquets and their use among SpRs and ODAs. This study highlights the need for amendments in training to improve the knowledge and awareness of medical practitioners on the application and use of tourniquets to prevent adverse events and improve patient safety.
Treating the boxer's fracture in Wales: a postal survey
Authors: Jones Rhidian , Burdett Sadie , Jefferies Matthew , Guha Abhijit R 
Published: April 2010

INTRODUCTION There is no standardised treatment for fifth metacarpal neck fractures. Treatment of this common fracture can vary from immediate mobilisation to immobilisation in a plaster cast for 3 weeks. There is no literature identifying current practice amongst surgeons. SUBJECTS AND METHODS This survey's aim was to reveal current practice in Wales by means of a postal questionnaire sent to all Welsh orthopaedic consultants. RESULTS The questionnaire had a 60% response rate. Results demonstrated varied opinion regarding the degree of displacement warranting reduction. Overall, 10% of surgeons reduce the fracture at 30° of displacement, 29% at 40°, 18% at 50° and 20% at 60° of displacement. The treatment was also very varied. Most surgeons preferred to treat these fractures with neighbour strapping (43%,) while others preferred plaster immobilisation (39%) or immediate mobilisation (10%.) Only 22% of surgeons discharge these patients back to the community after their first visit to out-patients while 13% offer two follow-up appointments. CONCLUSIONS The treatment being offered for this common fracture in Wales is inconsistent. There is a need to develop evidence- based best practice guidelines which should standardise the treatment of this common injury. Perhaps, a large multicentre outcome study may enable this to be drawn up in the future.
Assessing the adequacy of procedure-specific consent forms in orthopaedic surgery against current methods of operative consent
Authors: Barritt Andrew W , Clark Laura , Teoh Victoria , Cohen Adam MM , Gibb Paul A 
Published: April 2010

INTRODUCTION This is an audit of patient understanding following their consent for orthopaedic procedures and uses information on new Orthoconsent forms endorsed by the British Orthopaedic Association as the set standard. The objectives were to: (i) assess whether patients& understanding of knee arthroscopy (KA) and total knee replacement (TKR) at the point of confirming their consent reaches the set standard; and (ii) to ascertain whether issuing procedure-specific Orthoconsent forms to patients can improve this understanding. SUBJECTS AND METHODS This was a prospective audit using questionnaires consisting of 26 (for KA) or 35 (for TKR) questions based on the appropriate Orthoconsent form in a department of orthopaedic surgery within a UK hospital. Participants were 100 patients undergoing KA and 60 patients undergoing TKR between February and July 2008. Participants were identified from sequential operating lists and all had capacity to give consent. During the first audit cycle, consent was discussed with the patient and documented on standard yellow NHS Trust approved generic consent forms. During the second audit cycle, patients were additionally supplied with the appropriate procedure-specific consent form downloaded from < www.orthoconsent.com > which they were required to read at home and sign on the morning of surgery. RESULTS Knee arthroscopy patients consented with only the standard yellow forms scored an average of 56.7%, rising to 80.5% with use of Orthoconsent forms. Similarly, total knee replacement patients& averages rose from 57.6% to 81.6%. CONCLUSIONS Providing patients with an Orthoconsent form significantly improves knowledge of their planned procedure as well as constituting a more robust means of information provision and consent documentation.
Prospective evaluation of a selective approach to cholangiography for suspected common bile duct stones
Authors: Horwood James , Akbar Fayaz , Davis Katherine , Morgan Richard 
Published: April 2010

INTRODUCTION Common bile duct (CBD) stones can cause serious morbidity or mortality, and evidence for them should be sought in all patients with symptomatic gallstones undergoing cholecystectomy. Routine intra-operative cholangiography (IOC) involves a large commitment of time and resources, so a policy of selective cholangiography was adopted. This study prospectively evaluated the policy of selective cholangiography for patients suspected of having choledocholithiasis, and aimed to identify the factors most likely to predict the presence of CBD stones positively. PATIENTS AND METHODS Data from 501 consecutive patients undergoing laparoscopic cholecystectomy (LC) for symptomatic gallstones, of whom 166 underwent IOC for suspected CBD stones, were prospectively collected. Suspicion of choledocholithiasis was based upon: (i) deranged liver function tests (past or present); (ii) history of jaundice (past or present) or acute pancreatitis; (iii) a dilated CBD or demonstration of CBD stones on imaging; or (iv) a combination of these factors. Patient demographics, intra-operative findings, complications and clinical outcomes were recorded. RESULTS Sixty-four cholangiograms were positive (39%). All indications for cholangiogram yielded positive results. Current jaundice yielded the highest positive predictive value (PPV; 86%). A dilated CBD on pre-operative imaging gave a PPV of 45% for CBD calculi; a history of pancreatitis produced a 26% PPV for CBD calculi. Patients with the presence of several factors suggestive of CBD stones yielded higher numbers of positive cholangiograms. Of the 64 patients having a laparoscopic common bile duct exploration (LCBDE), four (6%) required endoscopic retrograde cholangiopancreatography (ERCP) for retained stones (94% successful surgical clearance of the common bile duct) and one (2%) for a bile leak. Of the 335 patients undergoing LC alone, three (0.9%) re-presented with a retained stone, requiring intervention. There were 12 (7%) requiring conversion to open operation. CONCLUSIONS A selective policy for intra-operative cholangiography yields acceptably high positive results. Pre-operatively, asymptomatic bile duct stones rarely present following LC; thus, routine imaging of the biliary tree for occult calculi can safely be avoided. Therefore, a rationing approach to the use of intra-operative imaging based on the pre-operative indicators presented in this paper, successfully identifies those patients with bile duct stones requiring exploration. Laparoscopic bile duct exploration, performed by an experienced laparoscopic surgeon, is a safe and effective method of clearing the bile duct of calculi, with minimal complications, avoiding the necessity for an additional intervention and prolonged hospital stay.
Evaluation of the introduction of a standardised protocol for the staging and follow-up of colorectal cancer on resection rates for liver metastases
Authors: Tiernan J , Briggs CD , Irving GRB , Swinscoe MT , Peterson M , Cameron IC 
Published: April 2010

INTRODUCTION In 2004, an audit in our unit demonstrated wide variation in liver resection rates for colorectal cancer (CRC) metastases within the cancer network. Subsequently, a network-wide CT-based follow-up and referral policy was introduced for all patients. A second audit was performed to assess the impact of the guidelines on liver resection rates. SUBJECTS AND METHODS Analysis of prospective liver resection database between 1997 and 2004 and after the introduction of standardised guidelines between January 2005 and April 2008. RESULTS A total of 362 patients underwent liver resection for CRC metastases between 1997 and 2008, 237 prior to the introduction of the referral guidelines and 125 after. Liver resection rates according to referring hospital varied from 0.92 to 2.32 per 100,000 population before guidelines were introduced. After 2005, resection rates from the four district hospitals standardised (1.68–1.84 per 100,000 population), but the central unit rate (Sheffield) remained significantly higher (2.67 per 100,000 population). No significant difference in 1-year disease-free survival between patients from Sheffield and the outlying hospitals was found (P = 0.553). CONCLUSIONS Introduction of a referral protocol standardised resection rates from the four district hospitals, but these remain lower compared to the specialist centre. The wide-spread adoption of a policy to discuss all patients with liver metastases at an advanced disease multidisciplinary team meeting, in the presence of hepatobiliary specialists, may further increase resection rates across the UK.