Bridge weigh-in-motion system and Structural Health Monitoring using fiber optic sensors

There have been over 3000 bridge weigh-in-motion (B-WIM) installations in 25 countries worldwide, this has led vast improvements in post processing of B-WIM systems since its introduction in the 1970’s. This paper introduces a new low-power B-WIM system using fibre optic sensors (FOS). The system consisted of a series of FOS which were attached to the soffit of an existing integral bridge with a single span of 19m. The site selection criteria and full installation process has been detailed in the paper. A method of calibration was adopted using live traffic at the bridge site and based on this calibration the accuracy of the system was determined.

Plateau:for tape

commissioned by Adventures in Motion Pictures (Matthew Bourne) for Dance Umbrella Festival< London

Migratory navigation in birds: new opportunities in an era of fast-developing tracking technology

Birds have remained the dominant model for studying the mechanisms of animal navigation for decades, with much of what has been discovered coming from laboratory studies or model systems. The miniaturisation of tracking technology in recent years now promises opportunities for studying navigation during migration itself (migratory navigation) on an unprecedented scale. Even if migration tracking studies are principally being designed for other purposes, we argue that attention to salient environmental variables during the design or analysis of a study may enable a host of navigational questions to be addressed, greatly enriching the field. We explore candidate variables in the form of a series of contrasts (e. g. land vs ocean or night vs day migration), which may vary naturally between migratory species, populations or even within the life span of a migrating individual. We discuss how these contrasts might help address questions of sensory mechanisms, spatiotemporal representational strategies and adaptive variation in navigational ability. We suggest that this comparative approach may help enrich our knowledge about the natural history of migratory navigation in birds.

Making geography mobile: using location aware technology to improve student performance in physical geography

With the increased availability of new technologies, geography educators are revisiting their pedagogical approaches to teaching and calling for opportunities to share local and international practices which will enhance the learning experience and improve students’ performance. This paper reports on the use of handheld mobile devices, fitted with GPS, by secondary (high) school pupils in geography. Two location-aware activities were completed over one academic year (one per semester) and pre-test and post-test scores for both topics revealed a statistically significant increase in pupils’ performance as measured by the standard national assessments. A learner centred educational approach was adopted with the first mobile learning activity being created by the teacher as an exemplar of effective mobile learning design. Pupils built on their experiences of using mobile learning when they were required to created their own location aware learning task for peer use. An analysis of the qualitative data from the pupils’ journals, group diaries and focus group interviews revealed the five pillars of learner centred education are addressed when using location aware technologies and the use of handheld mobile devices offered greater flexibility and autonomy to the pupils thus altering the level of power and control away from the teacher. Due to the relatively small number of participants in the study, the results are more informative than generalisable however in light of the growing interest in geo-spatial technologies in geography education, this paper offers encouragement and insight into the use of location aware technology in a compulsory school context

Developments in retrodirective array technology

There has been significant interest in retrodirective antennas, especially considering the wealth of applications that could be significantly enhanced, or created, by the use of such technology. There is enormous potential for retrodirective antennas where complicated automatic tracking systems would benefit from being replaced by much simpler systems. Retrodirective array technology offers one solution pathway since it can offer extremely fast tracking with relatively simple circuitry. Retrodirective or self-steering arrays are suited for low radio frequency (RF) power mobile terminal use particularly on or between un-stabilised vehicles. In this type of operational scenario, high degrees of relative movement are expected, and power consumption and weight of the antenna must be kept to a minimum. In this study, the authors give a brief historical review of basic retrodirective technology and elaborate on some recent developments at Queens University of Belfast associated with retrodirective antenna technology in relation to, two-way communications, ultrafast RADAR, microwave imaging, spatial power transmission, mitigation of multipath effects and spatial encryption.

Motion Management for Radical Radiotherapy in Non-small Cell Lung Cancer

Intrafraction tumour motion is an issue that is of increased interest in the era of image-guided radiotherapy. It is particularly relevant for non-small cell lung cancer, for which a number of recent developments are in use to aid with motion management in the delivery of radical radiotherapy. The ability to deliver hypofractionated ablative doses, such as in stereotactic radiotherapy, has been aided by improvements in the ability to analyse tumour motion and amend treatment delivery. In addition, accounting for tumour motion can enable dose escalation to occur by reducing the normal tissue being irradiated by virtue of a reduction in target volumes. Motion management for lung tumours incorporates five key components: imaging, breath-hold techniques, abdominal compression, respiratory tracking and respiratory gating. These will be described, together with the relevant benefits and associated complexities. Many studies have described improved dosimetric coverage and reduced normal tissue complication probability rates when using motion management techniques. Despite the widespread uptake of many of these techniques, there is a paucity of literature reporting improved outcome in overall survival and local control for patients whenever motion management techniques are used. This overview will review the extent of lung tumour motion, ways in which motion is detected and summarise the key methods used in motion management.

Multi-Level Wordline Driver for Low Power SRAMs in Nano-Scale CMOS Technology

In this paper, a multi-level wordline driver scheme is presented to improve SRAM read and write stability while lowering power consumption during hold operation. The proposed circuit applies a shaped wordline voltage pulse during read mode and a boosted wordline pulse during write mode. During read, the applied shaped pulse is tuned at nominal voltage for short period of time, whereas for the remaining access time, the wordline voltage is reduced to a lower level. This pulse results in improved read noise margin without any degradation in access time which is explained by examining the dynamic and nonlinear behavior of the SRAM cell. Furthermore, during hold mode, the wordline voltage starts from a negative value and reaches zero voltage, resulting in a lower leakage current compared to conventional SRAM. Our simulations using TSMC 65nm process show that the proposed wordline driver results in 2X improvement in static read noise margin while the write margin is improved by 3X. In addition, the total leakage of the proposed SRAM is reduced by 10% while the total power is improved by 12% in the worst case scenario of a single SRAM cell. The total area penalty is 10% for a 128Kb standard SRAM array.

Rapid detection of health-care-associated bloodstream infection in critical care using multipathogen real-time polymerase chain reaction technology: a diagnostic accuracy study and systematic review

Background: There is growing interest in the potential utility of real-time polymerase chain reaction (PCR) in diagnosing bloodstream infection by detecting pathogen deoxyribonucleic acid (DNA) in blood samples within a few hours. SeptiFast (Roche Diagnostics GmBH, Mannheim, Germany) is a multipathogen probe-based system targeting ribosomal DNA sequences of bacteria and fungi. It detects and identifies the commonest pathogens causing bloodstream infection. As background to this study, we report a systematic review of Phase III diagnostic accuracy studies of SeptiFast, which reveals uncertainty about its likely clinical utility based on widespread evidence of deficiencies in study design and reporting with a high risk of bias. 

Objective: Determine the accuracy of SeptiFast real-time PCR for the detection of health-care-associated bloodstream infection, against standard microbiological culture. 

Design: Prospective multicentre Phase III clinical diagnostic accuracy study using the standards for the reporting of diagnostic accuracy studies criteria. 

Setting: Critical care departments within NHS hospitals in the north-west of England. 

Participants: Adult patients requiring blood culture (BC) when developing new signs of systemic inflammation. 

Main outcome measures: SeptiFast real-time PCR results at species/genus level compared with microbiological culture in association with independent adjudication of infection. Metrics of diagnostic accuracy were derived including sensitivity, specificity, likelihood ratios and predictive values, with their 95% confidence intervals (CIs). Latent class analysis was used to explore the diagnostic performance of culture as a reference standard. 

Results: Of 1006 new patient episodes of systemic inflammation in 853 patients, 922 (92%) met the inclusion criteria and provided sufficient information for analysis. Index test assay failure occurred on 69 (7%) occasions. Adult patients had been exposed to a median of 8 days (interquartile range 4–16 days) of hospital care, had high levels of organ support activities and recent antibiotic exposure. SeptiFast real-time PCR, when compared with culture-proven bloodstream infection at species/genus level, had better specificity (85.8%, 95% CI 83.3% to 88.1%) than sensitivity (50%, 95% CI 39.1% to 60.8%). When compared with pooled diagnostic metrics derived from our systematic review, our clinical study revealed lower test accuracy of SeptiFast real-time PCR, mainly as a result of low diagnostic sensitivity. There was a low prevalence of BC-proven pathogens in these patients (9.2%, 95% CI 7.4% to 11.2%) such that the post-test probabilities of both a positive (26.3%, 95% CI 19.8% to 33.7%) and a negative SeptiFast test (5.6%, 95% CI 4.1% to 7.4%) indicate the potential limitations of this technology in the diagnosis of bloodstream infection. However, latent class analysis indicates that BC has a low sensitivity, questioning its relevance as a reference test in this setting. Using this analysis approach, the sensitivity of the SeptiFast test was low but also appeared significantly better than BC. Blood samples identified as positive by either culture or SeptiFast real-time PCR were associated with a high probability (> 95%) of infection, indicating higher diagnostic rule-in utility than was apparent using conventional analyses of diagnostic accuracy. 

Conclusion: SeptiFast real-time PCR on blood samples may have rapid rule-in utility for the diagnosis of health-care-associated bloodstream infection but the lack of sensitivity is a significant limiting factor. Innovations aimed at improved diagnostic sensitivity of real-time PCR in this setting are urgently required. Future work recommendations include technology developments to improve the efficiency of pathogen DNA extraction and the capacity to detect a much broader range of pathogens and drug resistance genes and the application of new statistical approaches able to more reliably assess test performance in situation where the reference standard (e.g. blood culture in the setting of high antimicrobial use) is prone to error.

Ethnography of technological competence in clinical midwifery practice

Background. Concept analysis has identified three domains in the competent use of birth technology â?? interpersonal skills, professional knowledge and clinical proficiency â?? and tentative criteria for birth technology competence. Aim. Fieldwork was undertaken to observe, confirm and explore pre-defined attributes of birth technology competence. Method. The Swartz-Barcott and Kim (2000) hybrid model of concept development was expanded to include an ethnographic observation of theory in action. Findings. Key attributes of birth technology competence found in â??real-worldâ?? midwifery practice were skills in using the machines, decision-making and traditional midwifery skills. Conclusions. The confusion surrounding the use of technology in midwifery practice needs to be addressed by both professionals and educationalists. Midwives should be taught to value traditional midwifery skills alongside those of machine skills. The identification of a model of appropriate technology use is needed in midwifery.

Polarization and Angular Correlation Studies of X-Rays Emitted in Relativistic Ion-Atom Collisions

Particle and photon polarization phenomena occurring in collisions of relativistic ions with matter have recently attracted particular interest. Investiga- tions of the emitted characteristic x-ray and radiative electron capture radiation has been found to be a versatile tool for probing our present understanding of the dynamics of particles in extreme electromagnetic ¯elds. Owing to the progress in x-ray detector technology, in addition, accurate measurements of the linear po- larization for hard x-ray photons as well as the determination of the polarization plane became possible. This new diagnostic tool enables one today to derive in- formation about the polarization of the ion beams from the photon polarization features of the radiative electron capture process.

Characterisation of fluidised bed granulation processes using in situ Raman spectroscopy

Previous work by the authors Walker et al. [2007b. Fluidised bed characterisation using Raman spectroscopy: applications to pharmaceutical processing. Chemical Engineering Science 62, 3832–3838] illustrated that Raman spectroscopy could be used to provide 3-D maps of the concentration and chemical structure of particles in motion in a fluidised bed, within a relatively short (120 s) time window. Moreover, we reported that the technique, as outlined, has the potential to give detailed in-situ information on how the structure and composition of granules/powders within the fluidised bed (dryer or granulator) vary with the position and evolve with time. In this study we extended the original work by shortening the time window of the Raman spectroscopic analysis to 10 s, which has allowed the in-situ real-time characterisation of a fluidised bed granulation process. Here we show an important new use of the technique which allows in-situ measurement of the composition of the material within the fluidised bed in three spatial dimensions and as a function of time. This is achieved by recording Raman spectra using a probe positioned within the fluidised bed on a long-travel x–y–z stage. In these experiments the absolute Raman intensity is used to provide a direct measure of the amount of any given material in the probed volume, i.e. a particle density. Particle density profiles have been calculated over the granulation time and show how the volume of the fluidised bed decreases with an increase mean granule size. The Raman spectroscopy analysis indicated that nucleation/coalescence in this co-melt fluidised hot melt granulation system occurred over a relatively short time frame (t<30 s). The Raman spectroscopic technique demonstrated accurate correlation with independent granulation experiments which provided particle size distribution analysis. The similarity of the data indicates that the Raman spectra accurately represent solids ratios within the bed, and thus the techniques quantitative capabilities for future use in the pharmaceutical industry.

Research on Ultimate Loading Carrying Capacities in Concrete Bridge Deck Slabs with Consideration of Compressive Membrane Action

In the investigation of real loading capacities in concrete bridge deck slabs,the study of this type of structure was carried out with consideration of compressive membrane action.A series of experimental test of steel-concrete bridge structures was developed with the analysis of influences from the varying of structural parameters on loading capacities,including reinforcement percentages,supporting beam sizes and concrete compressive strength.Through the study of the experimental results,it was found that the real structural loading capacities are larger than those predicted by current design methods.Therefore,based on the previous research,a prediction method for loading capacities of concrete bridge deck slabs was established with consideration of CMA,which was built based on the plastic ultimate analysis.In this method,the lateral restraint stiffness subjected by concrete bridge deck slabs was provided.The proposed theoretical model is capable of predicting the loading capacities of this type of structure accurately with comparison of results from several bridge deck experimental tests.

A survey of sewer rehabilitation in Malaysia: application of trenchless technologies

This work presents a review of applicable sewer rehabilitation options using trenchless technology in Malaysia. The typical problems faced in wastewater collection systems are analysed and factors that determine the selection method are outlined. This study also highlights the necessary steps to be taken prior to the rehabilitation work. The trenchless technology reviewed here comprises repair, renovation and replacement options. The cost-effectiveness of different rehabilitation methods was identified to assess the economic viability of various options in the Malaysian context. This study reveals that not all the trenchless technologies available in the market are suitable for use in Malaysia, mainly due to incompatibility of the rehabilitation materials used. Furthermore, as trenchless rehabilitation generally involves higher capital outlay than open-cut methods, the choice of rehabilitation method has to be made on a case-to-case basis.