Health monitoring of short-and medium-spen bridges using an improved modal strain energy method

Increasing the importance and use of infrastructures such as bridges, demands more effective structural health monitoring (SHM) systems. SHM has well addressed the damage detection issues through several methods such as modal strain energy (MSE). Many of the available MSE methods either have been validated for limited type of structures such as beams or their performance is not satisfactory. Therefore, it requires a further improvement and validation of them for different types of structures. In this study, an MSE method was mathematically improved to precisely quantify the structural damage at an early stage of formation. Initially, the MSE equation was accurately formulated considering the damaged stiffness and then it was used for derivation of a more accurate sensitivity matrix. Verification of the improved method was done through two plane structures: a steel truss bridge and a concrete frame bridge models that demonstrate the framework of a short- and medium-span of bridge samples. Two damage scenarios including single- and multiple-damage were considered to occur in each structure. Then, for each structure, both intact and damaged, modal analysis was performed using STRAND7. Effects of up to 5 per cent noise were also comprised. The simulated mode shapes and natural frequencies derived were then imported to a MATLAB code. The results indicate that the improved method converges fast and performs well in agreement with numerical assumptions with few computational cycles. In presence of some noise level, it performs quite well too. The findings of this study can be numerically extended to 2D infrastructures particularly short- and medium-span bridges to detect the damage and quantify it more accurately. The method is capable of providing a proper SHM that facilitates timely maintenance of bridges to minimise the possible loss of lives and properties.

Soil moisture monitoring at the field scale using neutron probe

Measurement of the moisture variation in soils is required for geotechnical design and research because soil properties and behavior can vary as moisture content changes. The neutron probe, which was developed more than 40 years ago, is commonly used to monitor soil moisture variation in the field. This study reports a full-scale field monitoring of soil moisture using a neutron moisture probe for a period of more than 2 years in the Melbourne (Australia) region. On the basis of soil types available in the Melbourne region, 23 sites were chosen for moisture monitoring down to a depth of 1500 mm. The field calibration method was used to develop correlations relating the volumetric moisture content and neutron counts. Observed results showed that the deepest “wetting front” during the wet season was limited to the top 800 to 1000 mm of soil whilst the top soil layer down to about 550mmresponded almost immediately to the rainfall events. At greater depths (550 to 800mmand below 800 mm), the moisture variations were relatively low and displayed predominantly periodic fluctuations. This periodic nature was captured with Fourier analysis to develop a cyclic moisture model on the basis of an analytical solution of a one-dimensional moisture flow equation for homogeneous soils. It is argued that the model developed can be used to predict the soil moisture variations as applicable to buried structures such as pipes.

Monitoring phase behavior of sub- and supercritical CO2 confined in porous fractal silica with 85% porosity

Phase behavior of CO2 confined in porous fractal silica with volume fraction of SiO2 φs = 0.15 was investigated using small-angle neutron scattering (SANS) and ultrasmall-angle neutron scattering (USANS) techniques. The range of fluid densities (0<(FCO2)bulk<0.977 g/cm3) and temperatures (T=22 °C, 35 and 60 °C) corresponded to gaseous, liquid, near critical and supercritical conditions of the bulk fluid. The results revealed formation of a dense adsorbed phase in small pores with sizes D<40 A° at all temperatures. At low pressure (P <55 bar, (FCO2)bulk <0.2 g/cm3) the average fluid density in pores may exceed the density of bulk fluid by a factor up to 6.5 at T=22 °C. This “enrichment factor” gradually decreases with temperature, however significant fluid densification in small pores still exists at temperature T=60°C, i.e., far above the liquid-gas critical temperature of bulk CO2 (TC=31.1 °C). Larger pores are only partially filled with liquid-like adsorbed layer which coexists with unadsorbed fluid in the pore core. With increasing pressure, all pores become uniformly filled with the fluid, showing no measurable enrichment or depletion of the porous matrix with CO2.

On-line scale monitoring device

Developments in evaporator cleaning have accelerated in the past 10 years as a result of an extended period of research into scale formation and scale composition. Chemical cleaning still provides the most cost effective method of cleaning the evaporators. The paper describes a system that was designed to obtain on-line samples of evaporator scale negating the need to open up hot evaporator vessels for scale collection. This system was successfully implemented in a number of evaporators at a sugar mill. This paper also describes a recent experience in a sugar factory in which the cleaning procedure was slightly modified, resulting in effective removal of intractable scale.

On-line scale monitoring device

Developments in evaporator cleaning have accelerated in the past 10 years as a result of an extended period of research into scale formation and scale composition. Chemical cleaning still provides the most cost effective method of cleaning the evaporators. The paper describes a system that was designed to obtain on-line samples of evaporator scale negating the need to open up hot evaporator vessels for scale collection. This system was successfully implemented in a number of evaporators at a sugar mill. This paper also describes a recent experience in a sugar factory in which the cleaning procedure was slightly modified resulting in effective removal of intractable scale.

A prospective model of care for breast cancer rehabilitation : bone health and arthralgias

Musculoskeletal health can be compromised by breast cancer treatment. In particular, bone loss and arthralgias are prevalent side effects experienced by women treated with chemotherapy and/or adjuvant endocrine therapy. Bone loss leads to osteoporosis and related fractures, while arthralgias threaten quality of life and compliance to treatment. Because the processes that lead to these musculoskeletal problems are initiated when treatment begins, early identification of women who may be at higher risk of developing problems, routine monitoring of bone density and pain at certain stages of treatment, and prudent application of therapeutic interventions are key to preventing and/or minimizing musculoskeletal sequelae. Exercise may be a particularly suitable intervention strategy because of its potential to address a number of impairments; it may slow bone loss, appears to reduce joint pain in noncancer conditions, and improves other breast cancer outcomes. Research efforts continue in the areas of etiology, measurement, and treatment of bone loss and arthralgias. The purpose of this review is to provide an overview of the current knowledge on the management and treatment of bone loss and arthralgias in breast cancer survivors and to present a framework for rehabilitation care to preserve musculoskeletal health in women treated for breast cancer.

Simultaneous magnetic resonance imaging and consolidation measurement of articular cartilage

Magnetic resonance imaging (MRI) offers the opportunity to study biological tissues and processes in a non-disruptive manner. The technique shows promise for the study of the load-bearing performance (consolidation) of articular cartilage and changes in articular cartilage accompanying osteoarthritis. Consolidation of articular cartilage involves the recording of two transient characteristics: the change over time of strain and the hydrostatic excess pore pressure (HEPP). MRI study of cartilage consolidation under mechanical load is limited by difficulties in measuring the HEPP in the presence of the strong magnetic fields associated with the MRI technique. Here we describe the use of MRI to image and characterize bovine articular cartilage deforming under load in an MRI compatible consolidometer while monitoring pressure with a Fabry-Perot interferometer-based fiber-optic pressure transducer.

Medical science and the law

Advances in medical science have presented both law and bioethics with some of the most fascinating questions of our time. As science continues to forge ahead into new frontiers, in fields such as reproductive technology, human genetics, cloning technologies, and stem cell research, questions have arisen over the role for law in regulating this new terrain. The speed with which medical science has advanced, and continues to advance, can make it difficult to formulate appropriate regulatory responses. The rapid pace of scientific change and the increasing complexity of the science can present hurdles and barriers to the engagement of the public with science and the legal and ethical issues raised by it.

Alternate healing and medicine : the roles of naturopathy, homeopathy, osteopathy, chiropractic and medical practice in the health system

This thesis is concerned with understanding the roles of four alternate healing systems and medical practice in the community's health behaviour. The four alternate systems are naturopathy, homoeopathy, osteopathy and chiropractic. The research reported developed from work supported by the Committee of Inquiry into Chiropractic, Osteopathy, Homoeopathy and Naturopathy conducted under the chairmanship of Professor E. C. Webb set up by the Australian Government in 1975. The study concentrates on the factors which influence individual clients in their decisions to consult healers for treatment. An underlying assumption is that an analysis of the processes that effect such decisions will lead to further knowledge of the community's attitudes towards the functions of alternate healing and medicine. A review of the historical backgrounds and current status of the four alternate healing systems leads to the conclusion that they differ in a variety of areas. These areas include treatment modalities, historical backgrounds, occupational development and rapprochement with medicine. Homoeopathy, osteopathy and chiropractic emerged as distinct approaches to healing late in the nineteenth century. Naturopathy tends to be a philosophy or style of life as much as a health system in its own right. Their relationships with medicine also vary; osteopathy and naturopathy receive some acceptance, some homoeopaths are tolerated, whilst chiropractic is ostracised and vilified. A common paradigm of treatment underlies all four alternate approaches to healing. They all eschew the use of synthetic pharmaceuticals and invasive treatments and accept an indigenous theory of disease and a belief in the vis medicatrix naturae or the healing power of nature. An inevitable concomitant of this paradigm is that they believe that healing and health must be self-engendered. They rest within the client and his or her actions, not within the hands, skills or power of the healer. It is these characteristics combined with the alternate healers ' claims to espouse a similar scientific rationale for their approaches, and their functioning as parallel healers to medicine, that establishes their special relationship with medicine. This relationship become s more problematic in the face of medicine's hegemony and claim to unique legitimacy as the community's sole healing system. The interaction between these systems and medical practice can be gauged through articles related to the four alternate healing systems that have appeared in the medical literature. Interest has been cyclical but appears to have markedly increased in the past two decades. In this period it has included exploratory and descriptive writing; concern with controlling and/or eradicating the healers; desire to protect an ignorant and vulnerable public and. finally understanding and exploration of what the alternate healers might have to offer. At the same time, the public or institutionalized role has been one of denial and suppression through ostracism and legal constraints. In spite of medicine's position the alternate healing systems have found growing community acceptance so that it is problematical and probably unacceptable now to consider their use as a 'deviant ' health action. Increasing interest in the characteristics of clients has provided a consensus that they are similar to the adult population and are more likely to suffer from musculoskeletal and chronic illnesses. They are no more likely to be neurotic or gullible than the general community, but probably more practical and more oriented towards an active involvement in the healing process. The impact of these issues is explored, through comparing the strategies taken into account when choosing a treatment. These include attending one of the alternate healers exclusively for a condition; attending an alternate healer and a medical practitioner for the same problem; attending a medical practitioner solely or not consulting any healer. Respondents from surveys of alternate healer clients and the general community were classified according to their use of these four strategies, and the influences on their decisions at different stages of the treatment decision making process were compared.

Bluetooth and Wi-Fi MAC address based crowd data collection and monitoring : benefits, challenges and enhancement

This paper firstly presents the benefits and critical challenges on the use of Bluetooth and Wi-Fi for crowd data collection and monitoring. The major challenges include antenna characteristics, environment’s complexity and scanning features. Wi-Fi and Bluetooth are compared in this paper in terms of architecture, discovery time, popularity of use and signal strength. Type of antennas used and the environment’s complexity such as trees for outdoor and partitions for indoor spaces highly affect the scanning range. The aforementioned challenges are empirically evaluated by “real” experiments using Bluetooth and Wi-Fi Scanners. The issues related to the antenna characteristics are also highlighted by experimenting with different antenna types. Novel scanning approaches including Overlapped Zones and Single Point Multi-Range detection methods will be then presented and verified by real-world tests. These novel techniques will be applied for location identification of the MAC IDs captured that can extract more information about people movement dynamics.

Securing medical devices Part A : what’s available for endotracheal tubes?

Oral endotracheal tubes (ETTs) and nasogastric tubes (NGT) are common devices used in adult intensive care and numerous options exist for safe and comfortable securement of these devices. The aim of this project was to identify the available range of ETT and NGT securement devices in Australia as a resource for clinicians seeking to explore options for tube stabilisation. This article reports part A of this project: ETT securement options. Part B will report NGT device fixation options. Securing ETTs to ensure a patent airway with minimal ETT movement, promotion of patient comfort and absence of adverse events such as ETT dislodgement, unplanned extubation and device-related injury1, are essential critical care nursing actions. The ETT requires a fixation method that is robust yet does not traumatise or injure the mucosal tissues of the mouth and soft tissue of the lips.2,3 Choice of a securement apparatus is often determined by product availability in our units or hospitals but is also driven by evidence-based practice and clinician preference. Trying to put this information together can be difficult and time-consuming for the bedside clinician...

Securing medical devices Part B : what’s available for nasogastric tubes?

This article is the second part of a two-part series examining securement options for commonly used therapeutic devices in the adult intensive care unit. Part A focused on endotracheal device securement.1 This article addresses nasogastric tube (NGT) securement options and with the aim of identifying the available range of NGT securement devices in Australia as a resource for clinicians seeking to explore options for tube stabilisation. Nasogastric feeding or gastric decompression tubes are commonly inserted via the nostril/nares. The National Pressure Ulcer Advisory Panel (NPUAP) 2011 position statement on mucosal pressure injuries, highlighted that mucosal tissues are vulnerable to pressure from devices.2 Securing of these devices sometimes leads to pressure-related injury to the internal mucosa due to difficulty visualising the mucosa and failure to reposition the nasogastric tube to relieve the pressure in a particular area.3 The nasal orifice is much smaller than the oral cavity and regular tube position changes are vital to minimise the risk of mucosal damage and ulcer development.

Using objective physical activity measures with youth : How many days of monitoring are needed?

Purpose The purpose of this study was to establish the minimal number of days of monitoring required for accelerometers to assess usual physical activity in children. Methods A total of 381 students (189 M, 192 F) wore a CSA 7164 uniaxial accelerometer for seven consecutive days. To examine age-related trends students were grouped as follows: Group I: grades 1-3 (N = 92); Group II: grades 4-6 (N = 98); Group III: grades 7-9 (N = 97); Group IV: grades 10-12 (N = 94). Average daily time spent in moderate-to-vigorous physical activity (MVPA) was calculated from minute-by-minute activity counts using the regression equation developed by Freedson et al. (1997). Results Compared with adolescents in grades 7 to 12, children in grades 1 to 6 exhibited less day-to-day variability in MVPA behavior. Spearman-Brown analysts indicated that between 4 and 5 d of monitoring would be necessary to a achieve a reliability of 0.80 in children, and between 8 and 9 d of monitoring would be necessary to achieve a reliability of 0.80 in adolescents. Within all grade levels, the 7-d monitoring protocol produced acceptable estimates of daily participation in MVPA (R = 0.76 (0.71-0.81) to 0.87 (0.84-0.90)). Compared with weekdays, children exhibited significantly higher levels of MVPA on weekends, whereas adolescents exhibited significantly lower levels of MVPA on weekends. Principal components analysis revealed two distinct time components for MVPA during the day for children (early morning, rest of the day), and three distinct time components for MVPA during the day for adolescents (morning, afternoon, early evening). Conclusions These results indicate that a 7-d monitoring protocol provides reliable estimates of usual physical activity behavior in children and adolescents and accounts for potentially important differences in weekend versus weekday activity behavior as well as differences in activity patterns within a given day.

Advances in population surveillance for physical activity and sedentary behavior : reliability and validity of time use surveys

Many countries conduct regular national time use surveys, some of which date back as far as the 1960s. Time use surveys potentially provide more detailed and accurate national estimates of the prevalence of sedentary and physical activity behavior than more traditional self-report surveillance systems. In this study, the authors determined the reliability and validity of time use surveys for assessing sedentary and physical activity behavior. In 2006 and 2007, participants (n = 134) were recruited from work sites in the Australian state of New South Wales. Participants completed a 2-day time use diary twice, 7 days apart, and wore an accelerometer. The 2 diaries were compared for test-retest reliability, and comparison with the accelerometer determined concurrent validity. Participants with similar activity patterns during the 2 diary periods showed reliability intraclass correlations of 0.74 and 0.73 for nonoccupational sedentary behavior and moderate/vigorous physical activity, respectively. Comparison of the diary with the accelerometer showed Spearman correlations of 0.57-0.59 and 0.45-0.69 for nonoccupational sedentary behavior and moderate/vigorous physical activity, respectively. Time use surveys appear to be more valid for population surveillance of nonoccupational sedentary behavior and health-enhancing physical activity than more traditional surveillance systems. National time use surveys could be used to retrospectively study nonoccupational sedentary and physical activity behavior over the past 5 decades.