From the Past to the Future of Landfill Engineering Through Case Histories

The advances in landfill engineering are outlined based on a number of case histories illustrating past problems, hydraulic performance of clay liners, diffusive transport through liners, hydraulic containment and clogging of leachate collection systems. The importance of conventional geotechnical considerations (e.g. stability) will also be highlighted with reference to a number of cases. Finally, the recent advances in landfill operations are illustrated with respect to a modern landfill. It is concluded that, provided all key failure mechanisms are considered in the design, construction and operation of the facility, modern landfills should provide environmental protection both today and well into the future

Orthoptic Home Visits for Stroke Survivors: Results from a UK Professional Practice Survey.

AimOrthoptists are perhaps the only allied health profession without a standard home visits service in the UK, although it could arguably be of benefit to many orthoptic patients. The aim of this survey was to identify whether home visits are being offered, or have the potential to be offered, within the orthoptic profession.MethodA survey of the orthoptic professional body (BIOS) for the UK and Ireland was developed and data collected between January and March 2016. Descriptive analysis was used to report the quantitative findings. A thematic analysis approach was undertaken for the written responses within the free-text boxes of the survey.Results461 BIOS members responded to the survey (response rate of 30.7%). Ten hospital sites (3.7%) reported offering home visits, and 444 members (96.3%) reported that they do not offer home visits, with little desire or perceived need for such a service. Only certain patients reportedly meet requirements for an orthoptic home visit, including those unable to attend the hospital due to poor health, transport issues, reduced cognition, stroke and learning difficulties. Implementation barriers were reported including staff safety, assessment quality and cost.ConclusionHome visits are infrequently conducted within the orthoptic profession. However, where offered, certain patient groups were suggested to benefit from this service when they cannot attend hospital and thus, home visits could present a viable means of providing equitable visual care. Future research is required to explore orthoptic home visits compared to other forms of rehabilitation, and address concerns from the orthoptic professional body

Visual Impairment Screening Assessment (VISA) tool: pilot validation

Objective To report and evaluate a new Vision Impairment Screening Assessment (VISA) tool intended for use by the stroke team to improve identification of visual impairment in stroke survivors. Design Prospective case cohort comparative study. Setting Stroke units at two secondary care hospitals and one tertiary centre. Participants 116 stroke survivors were screened, 62 by naïve and 54 by non-naïve screeners. Main outcome measures Both the VISA screening tool and the comprehensive specialist vision assessment measured case history, visual acuity, eye alignment, eye movements, visual field and visual inattention. Results Full completion of VISA tool and specialist vision assessment was achieved for 89 stroke survivors. Missing data for one or more sections typically related to patient’s inability to complete the assessment. Sensitivity and specificity of the VISA screening tool were 90.24% and 85.29%, respectively; the positive and negative predictive values were 93.67% and 78.36%, respectively. Overall agreement was significant; k=0.736. Lowest agreement was found for screening of eye movement and visual inattention deficits. Conclusions This early validation of the VISA screening tool shows promise in improving detection accuracy for clinicians involved in stroke care who are not specialists in vision problems and lack formal eye training, with potential to lead to more prompt referral with fewer false positives and negatives. Pilot validation indicates acceptability of the VISA tool for screening of visual impairment in stroke survivors. Sensitivity and specificity were high indicating the potential accuracy of the VISA tool for screening purposes. Results of this study have guided the revision of the VISA screening tool ahead of full clinical validation

Performance investigation of a high-field active magnetic regenerator

Regenerative magnetic cycles are of interest for small-scale, high-efficiency cryogen liquefiers; however, commercially relevant performance has yet to be demonstrated. To develop improved engineering prototypes, an efficient modeling tool is required to screen the multi-parameter design space. In this work, we describe an active magnetic regenerative refrigerator prototype using a high-field superconducting magnet that produces a 100 K temperature span. Using the experimental data, a semi-analytic AMR element model is validated and enhanced system performance is simulated using liquid propane as a heat transfer fluid. In addition, the regenerator composition and fluid flow are simultaneously optimized using a differential evolution algorithm. Simulation results indicate that a natural gas liquefier with a 160 K temperature span and a second-law efficiency exceeding 20% is achievable

Multi-Center Traffic Management Advisor Operational Field Test Results

The Multi-Center Traffic Management Advisor (McTMA) is a research prototype system which seeks to bring time-based metering into the mainstream of air traffic control (ATC) operations. Time-based metering is an efficient alternative to traditional air traffic management techniques such as distance-based spacing (miles-in-trail spacing) and managed arrival reservoirs (airborne holding). While time-based metering has demonstrated significant benefit in terms of arrival throughput and arrival delay, its use to date has been limited to arrival operations at just nine airports nationally. Wide-scale adoption of time-based metering has been hampered, in part, by the limited scalability of metering automation. In order to realize the full spectrum of efficiency benefits possible with time-based metering, a much more modular, scalable time-based metering capability is required. With its distributed metering architecture, multi-center TMA offers such a capability