Innovative Design of Fire Training Simulator

This project outlines the innovative design of a fire detections training simulator. Fire protection systems are updated and changed rapidly as technology grows; training and guidelines for inspectors and safety professionals are crucial for the development of these systems. This project\u27s purpose is to design a fire inspection simulator to enhance awareness of and training fire safety professionals in the workplace. This interactive system uses specific devices that are not only cost effective but are widely accepted and used in multiple industries. OSHA 1910 Subpart L and NFPA 101 were used with NFPA 72 to inform the design of this system. The training provided will allow instructors and safety professionals an opportunity to review current fire protection devices as well as keep up to date with the most used fire protection devices in manufacturing. The outcome is to have proficient trainees with a basic understanding of how systems are implemented, designed, and maintained. By creating this innovative training system, we will have a tool up to date in the modern era that can be used by safety professionals for years to come. Our system can guarantee that trained individuals will be able to improve their knowledge and refine the skills required to operate the various kinds of alarm system that they may encounter in the workplace

Validated prediction of weld residual stresses in austenitic steel pipe girth welds before and after thermal ageing, part 1: Mock-up manufacture, residual stress measurements, and materials characterisation

A series of engineering-scale multi-pass pipe girth weld mock-ups were manufactured using conventional manual metal arc techniques from Esshete 1250 austenitic steel. They were characterised in detail, in order to provide validation benchmarks for finite element prediction of weld residual stresses. The fabrication sequence comprised initial solution heat treatment and quenching, manufacture of five closely spaced girth welds in a single assembly, and then separation into five individual weldments. Detailed welding records were kept, to allow subsequent calibration of weld heat source models. Residual stresses were measured using diverse methods (incremental deep hole drilling and the contour method), in both the as-welded condition and after thermal ageing at 650 °C. The measurements showed good agreement, providing reliable validation targets for predicted residual stresses in both states. Detailed mechanical property characterisation was performed on both parent material and weld metal, comprising monotonic and isothermal cyclic testing over a range of temperatures from ambient up to 1000 °C. The test data were used to derive a range of Lemaitre-Chaboche mixed isotropic-kinematic model parameter sets for use in finite element simulation. These welds and their supporting characterisation comprise a reliable benchmark for weld residual stress simulation in an engineering-scale weldment

Revision total knee arthroplasty in the young patient: is there trouble on the horizon?

BACKGROUND: The volume of total knee arthroplasties, including revisions, in young patients is expected to rise. The objective of this study was to compare the reasons for revision and re-revision total knee arthroplasties between younger and older patients, to determine the survivorship of revision total knee arthroplasties, and to identify risk factors associated with failure of revision in patients fifty years of age or younger. METHODS: Perioperative data were collected for all total knee arthroplasty revisions performed from August 1999 to December 2009. A cohort of eighty-four patients who were fifty years of age or younger and a cohort of eighty-four patients who were sixty to seventy years of age were matched for the date of surgery, sex, and body mass index (BMI). The etiology of failure of the index total knee arthroplasty and all subsequent revision total knee arthroplasties was determined. Kaplan-Meier survival curves were used to evaluate the timing of the primary failure and the survivorship of revision knee procedures. Finally, multivariate Cox regression was used to calculate risk ratios for the influence of age, sex, BMI, and the reason for the initial revision on survival of the revision total knee arthroplasty. RESULTS: The most common reason for the initial revision was aseptic loosening (27%; 95% confidence interval [CI] = 19% to 38%) in the younger cohort and infection (30%; 95% CI = 21% to 40%) in the older cohort. Of the twenty-five second revisions in younger patients, 32% (95% CI = 17% to 52%) were for infection, whereas 50% (95% CI = 32% to 68%) of the twenty-six second revisions in the older cohort were for infection. Cumulative six-year survival rates were 71.0% (95% CI = 60.7% to 83.0%) and 66.1% (95% CI = 54.5% to 80.2%) for revisions in the younger and older cohorts, respectively. Infection and a BMI of ≥40 kg/m2 posed the greatest risk of failure of revision procedures, with risk ratios of 2.731 (p = 0.006) and 2.934 (p = 0.009), respectively. CONCLUSIONS: The survivorship of knee revisions in younger patients is a cause of concern, and the higher rates of aseptic failure in these patients may be related to unique demands that they place on the reconstruction. Improvement in implant fixation and treatment of infection when these patients undergo revision total knee arthroplasty is needed. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence

A prospective analysis of glove perforation in primary and revision total hip and total knee arthroplasty.

Literature in regard to glove perforation rates in revision total joint arthroplasty (TJA) is scarce. Our purpose was to determine the incidence of perforation in revision TJA. Gloves from all scrubbed personnel were tested based on the American Society for Testing and Materials. A total of 3863 gloves were collected from 58 primary and 36 revision arthroplasty cases. Surgeons had a 3.7% outer-glove perforation rate in primary TJA compared with 8.9% in revision TJA. When both gloves were perforated, the outer-glove perforation was recognized intraoperatively 100% of the time, and the inner-glove perforation was noted only 19% of the time. The surgeon has the highest rate of glove perforation. Outer-glove perforations should prompt careful inspection of the inner glove

Peri-Operative Urodynamic Assessment has Poor Predictive Value for Developing Post-Operative Urinary Retention

Introduction: Post-operative urinary retention (POUR) following primary total joint arthroplasty (TJA) has a reported prevalence up to 35%. Risk factors for developing POUR have traditionally included surrogate markers such as the presence or absence of urologic disease. However, dynamic measurement of the renal system with post-void residual volumes (PVR) has not been investigated as a tool for assessing POUR risk. Methods: All male TJA patients underwent an pre-operative screen for POUR, including PVR measurements, patient-derived subjective urinary retention scores, and assessment of urologic disease. This was combined with a post-operative monitoring and catheterization protocol developed in partnership with a Urologist. Patient records were retrospectively reviewed and assessed whether pre-operative PVR cutoffs or urinary retention scores were associated with developing POUR. Proportions were evaluated with the chi square test, while continuous variables were evaluated by logistic regression analysis. Receiver-operator characteristic (ROC) curves were utilized to determine the efficacy of using urodynamic variables as a predictor of developing POUR. Results: Two hundred and fifty-two (252) male patients were reviewed who had a mean age of 64.9 years and mean BMI 30.8 kg/m2. The overall rate of POUR was 5.2%; the rate of protocol-driven catheterization was higher (19.8%). Patient urinary retentions scores were not associated with the risk of POUR. Elevated pre-operative PVR (\u3e10 cc) alone and in combination with a history of urologic disease was significantly associated with POUR (p \u3c 0.001 and p = 0.001, respectively). However, both had low positive-predictive values (10.5 and 18.2%, respectively), despite high negative predictive values (99.2 and 97.9%, respectively). Utilization of PVR resulted in moderate sensitivity (91.6%) and low specificity (72.1%) with an AUC of 0.694. Discussion: Urodynamic measurements and patient urinary retention scores, as part of institutional pre-operative screening, have limited value in determining risk of POUR. False-positive rates of up to ~90% were observed with correspondingly low specificity. The authors call into question the utility of obtaining these measurements pre-operatively, particularly as they have no modifiable impact on institutional post-operative catheterization protocol

Characteristics and Antibiotic Use Associated With Short-Term Risk of Clostridium difficile Infection Among Hospitalized Patients

Objectives—Polymerase chain reaction (PCR) has been shown to have an excellent sensitivity and specificity for the detection of Clostridium difficile infection (CDI). Little is known about risk factors for CDI within 14 days of an initial negative test. We sought to determine the characteristics among hospitalized patients associated with risk of short-term acquisition of CDI. Methods—A case-control study was conducted. Cases were patients who converted from PCR negative to positive within 14 days. Each case was matched with three controls. Conditional logistic regression was used to estimate the association between patient characteristics and CDI. Results—Of the 30 patients in our study who had a positive PCR within 14 days of a first negative PCR (cases), 15 (50%) occurred within 7 days of the initial test. Cases had a higher proportion of intravenous vancomycin use in the previous 8 weeks (odds ratio [OR], 3.38; 95% confidence interval [CI], 1.34-8.49) and were less likely to have recent antiviral agent use (OR, 0.30; 95% CI, 0.11-0.83) compared with controls. Conclusions—In hospitalized patients, treatment with intravenous vancomycin within the prior 8 weeks of a first negative PCR test for C difficile is a risk factor for short-term risk for hospital-acquired CDI. Repeat testing guidelines for C difficile PCR should take into consideration patients who may be at high risk for short-term acquisition of CDI