Behaviour of concrete filled stainless steel elliptical hollow sections

This paper presents the behaviour and design of axially loaded concrete filled stainless steel elliptical hollow sections. The experimental investigation was conducted using normal and high strength concrete of 30 and 100 MPa. The current study is based on stub column tests and is therefore limited to cross-section capacity. Based on the existing design guidance in Eurocode 4 for composite columns, the proposed design equations use the continuous strength method to determine the strength of the stainless steel material. It is found to provide the most accurate and consistent prediction of the axial capacity of the composite concrete filled stainless steel elliptical hollow sections due largely to the more precise assessment of the contribution of the stainless steel tube to the composite resistance

Royal Wedding: A Mod(ern) Twist

The Royal Wedding dress was designed within a 20 piece conceptual apparel line, of which three garments were constructed. The garment was designed in response to the concept of modern royalty (Prince William and Kate Middleton) being wed in a time of heightened moral and social values, harkening those of mid-century America. Therefore, the garment toes the line between tradition and modernity with a rebellious nod towards 1960’s mod stylings

Benthic oxygen exchange in a live coralline algal bed and an adjacent sandy habitat: an eddy covariance study

Coralline algal (maerl) beds are widespread, slow-growing, structurally complex perennial habitats that support high biodiversity, yet are significantly understudied compared to seagrass beds or kelp forests. We present the first eddy covariance (EC) study on a live maerl bed, assessing the community benthic gross primary productivity (GPP), respiration (R), and net ecosystem metabolism (NEM) derived from diel EC time series collected during 5 seasonal measurement campaigns in temperate Loch Sween, Scotland. Measurements were also carried out at an adjacent (~20 m distant) permeable sandy habitat. The O2 exchange rate was highly dynamic, driven by light availability and the ambient tidally-driven flow velocity. Linear relationships between the EC O2 fluxes and available light indicate that the benthic phototrophic communities were lightlimited. Compensation irradiance (Ec) varied seasonally and was typically ~1.8-fold lower at the maerl bed compared to the sand. Substantial GPP was evident at both sites; however, the maerl bed and the sand habitat were net heterotrophic during each sampling campaign. Additional inputs of ~4 and ~7 mol m-2 yr-1 of carbon at the maerl bed and sand site, respectively, were required to sustain the benthic O2 demand. Thus, the 2 benthic habitats efficiently entrap organic carbon and are sinks of organic material in the coastal zone. Parallel deployment of 0.1 m2 benthic chambers during nighttime revealed O2 uptake rates that varied by up to ~8-fold between replicate chambers (from -0.4 to -3.0 mmol O2 m-2 h-1; n = 4). However, despite extensive O2 flux variability on meter horizontal scales, mean rates of O2 uptake as resolved in parallel by chambers and EC were typically within 20% of one another

Automated hippocampal segmentation in patients with epilepsy: Available free online

Hippocampal sclerosis, a common cause of refractory focal epilepsy, requires hippocampal volumetry for accurate diagnosis and surgical planning. Manual segmentation is time-consuming and subject to interrater/intrarater variability. Automated algorithms perform poorly in patients with temporal lobe epilepsy. We validate and make freely available online a novel automated method

Assessment of the feasibility of an ultra-low power, wireless digital patch for the continuous ambulatory monitoring of vital signs.

BACKGROUND AND OBJECTIVES: Vital signs are usually recorded at 4–8 h intervals in hospital patients, and deterioration between measurements can have serious consequences. The primary study objective was to assess agreement between a new ultra-low power, wireless and wearable surveillance system for continuous ambulatory monitoring of vital signs and a widely used clinical vital signs monitor. The secondary objective was to examine the system's ability to automatically identify and reject invalid physiological data. SETTING: Single hospital centre. PARTICIPANTS: Heart and respiratory rate were recorded over 2 h in 20 patients undergoing elective surgery and a second group of 41 patients with comorbid conditions, in the general ward. OUTCOME MEASURES: Primary outcome measures were limits of agreement and bias. The secondary outcome measure was proportion of data rejected. RESULTS: The digital patch provided reliable heart rate values in the majority of patients (about 80%) with normal sinus rhythm, and in the presence of abnormal ECG recordings (excluding aperiodic arrhythmias such as atrial fibrillation). The mean difference between systems was less than ±1 bpm in all patient groups studied. Although respiratory data were more frequently rejected as invalid because of the high sensitivity of impedance pneumography to motion artefacts, valid rates were reported for 50% of recordings with a mean difference of less than ±1 brpm compared with the bedside monitor. Correlation between systems was statistically significant (p<0.0001) for heart and respiratory rate, apart from respiratory rate in patients with atrial fibrillation (p=0.02). CONCLUSIONS: Overall agreement between digital patch and clinical monitor was satisfactory, as was the efficacy of the system for automatic rejection of invalid data. Wireless monitoring technologies, such as the one tested, may offer clinical value when implemented as part of wider hospital systems that integrate and support existing clinical protocols and workflows

The Effects of Professional Learning Communities on Student Achievement

The purpose of this study was to examine data from the Early Childhood Longitudinal Study: Kindergarten Class of 1998-99 (ECLS-K) report, identify questions and statements that correlate to the dimensions of professional learning communities (PLCs), and determine the effect PLCs have on student achievement based on the ECLS-K data. In addition, the rationale for doing this research was to measure growth in student achievement over time. A multilevel growth model was used for this research. Univariate analysis was conducted in order to reveal frequencies and percentages associated with teacher responses. Bivariate analysis was applied in order to determine the inter-correlations between the fourteen variables. Once the inter-correlations were determined from the bivariate analysis, principal component analysis was applied in order to reveal the theoretical relationship between the variables. Through the use of principal components a set of correlated variables is transformed into a set of structure coefficient: support and collaborative. Finally, a multilevel growth model was used in order to determine the effect that each variable within the support and collaborative structure coefficients had on student achievement over time. This study revealed a number of variables within the ECLS-K report that correspond to the dimensions of PLCs have a statistically significant effect on student achievement in math and reading over time. This study demonstrated that support and collaborative variables within PLCs have a positive effect on both math and reading IRT achievement from 3rd grade to 5th grade

Operational and Technical Updates to the Object Reentry Survival Analysis Tool

The Object Reentry Survival Analysis Tool (ORSAT) has been used in the NASA Orbital Debris Program Office for over 25 years to estimate risk due to uncontrolled reentry of spacecraft and rocket bodies. Development over the last 3 years has included: a major change to the treatment of carbon fiber- and glass fiber-reinforced plastics (CFRP and GFRP, respectively); an updated atmospheric model; a new model for computing casualty area around an impacting debris object; and a newly-implemented scheme to determine the breakup altitude of a reentry object. Software also was written to automatically perform parameter sweeps in ORSAT to allow for uncertainty quantification and sensitivity analysis for components with borderline demisability. These updates have improved the speed and fidelity of the reentry analysis performed using ORSAT, and have allowed for improved engineering understanding by estimating the uncertainty for each components survivability. A statistical model for initial conditions captures the latitude bias in population density, a large improvement over the previous inclination-based latitude-averaged models. A sample spacecraft has been analyzed with standard techniques using ORSAT 6.2.1 and again using all the updated models; we will demonstrate the variation in the total debris casualty area and overall expectation of casualty

The effect of hydrothermal alteration on the mechanical behaviour of rockmass

The Xantho case study aims to quantify the influence that hydrothermal alteration type and intensity has on the mechanical behaviour of the Xantho rockmass at the Gossan Hill volcanogenic massive sulfide (VMS) Zn-Cu-Pb underground mine. Classifying fracture frequency domains in drill core by the type and intensity of the secondary hydrothermal alteration assemblage, the Xantho case study displays a quantifiable distinction between the mechanical behaviour of the chlorite altered and silica altered intact rocks and rockmass. Supplementary classification of altered fracture domains by lithology and geological setting show how the different material properties and gross textural character of the stratified volcanoclastic sediments and massive igneous intrusions influence the development of fractures in a predictable manner. Characterisation and quantification of the rockmass using the geological strength index provides three significant rockmass quality populations that highlight the importance of alteration type on the condition of the discontinuity and draws a distinction between volcanoclastic sediments and igneous intrusions. Numerical modelling of the chlorite and silica rockmass using the Hoek-Brown failure criterion displays marked behaviour near an underground excavation and coupled with the location of strong core disking, illustrate the role that hydrothermal alteration may have in distributing far-field stress

An Experimental and Theoretical Investigation of the Effects of Supply Air Conditions on Computational Efficiency in Data Centers Employing Aisle Containment

Aisle containment is increasingly common in data centres, and is widely believed to improve efficiency and effectiveness of cooling. Investigations into the impacts of aisle containment on the behavior and power consumption of cooling infrastructure and servers have been limited. Nor has the impact of supply air conditions on these factors been extensively investigated. This work uses measurements of bypass in a test data centre and observations on server behavior in a wind tunnel, in conjunction with a system model, to investigate the efficiency with which computations can be undertaken in an aisle contained data centre, and how this is impacted by supply air conditions