Distributed fiber optic sensors for monitoring reinforced concrete piles using Brillouin scattering

In this paper we report on advances made in the installation and use of distributed fiber optic sensors to monitor reinforced concrete piles subjected to static load tests. Eight concrete test piles, at three construction sites in London, have recently been instrumented with embedded DFOS. The Brillouin optical time domain reflectometry (BOTDR) technique was used to measure the changes in internal strain and temperature of the piles, during concrete curing and during load testing. These data were used to assess the quality of the pile and derive the load capacity parameters to be used in the foundation design of tall buildings which are to be erected on these sites. The measurements obtained from the DFOS system agreed well with the measurements taken simultaneously using conventional point sensors embedded in the piles. Whereas the conventional sensors only provided measurements at a small number of locations within the piles, the DFOS system made it possible to record the complete strain / temperature profiles along the length of the piles.The authors would like to acknowledge the contribution of (listed in alphabetical order): Hyungjoon Seo, Jason Shardelow, Peter Knott, Yi Rui and Zili Li from CSIC; Duncan Nicholson, Landi Proctor, Stuart Pennington and Vivien Kwan from Ove Arup & Partners Ltd.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by SPIE

Distributed fibre optic sensors for measuring strain and temperature of cast-in-situ concrete test piles

In this paper we present the use of distributed fibre optic sensor (DFOS) technology to measure the temperature and strain of reinforced concrete test piles during construction and during static load tests. Eight test piles were recently instrumented with DFOS, on three construction sites in London, by the Cambridge Centre for Smart Infrastructure and Construction (CSIC), in collaboration with Ove Arup & Partners Ltd. The concrete curing temperature profiles of the piles were used to detect the presence of significant defects in the piles. The load test strain profiles along the length of the piles were used to determine the load capacity of the piles and estimate the design parameters of the various soil strata, as well as the internal relative displacement of the piles under various loads. Being distributed in nature, DFOS give a much more detailed picture of the performance of a test pile, as compared to traditional embedded point sensors, such as vibrating wire strain gauges and extensometers. This is demonstrated with a sample of data obtained from one of the instrumented test piles.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by ICE Publishing

Search for a-Cluster States in the Giant Resonance Region

Supported by the National Science Foundation and Indiana Universit

Complex Relationship of Body Mass Index with Mortality in Patients with Critical Limb Ischemia Undergoing Endovascular Treatment

ObjectiveTo investigate the relationship between body mass index (BMI) and long-term outcomes of patients with CLI after endovascular treatment (EVT).DesignRetrospective multicenter study.Subjects1088 consecutive patients (1306 limbs, mean age 72 ± 10 years) with CLI who underwent EVT for isolated infrapopliteal artery lesions were evaluated. These subjects were identified in the J-BEAT III registry.MethodsThe patients were divided into groups based on BMI <18.5 kg/m2 (underweight, n = 188; 219 limbs), 18.5 to 24.9 kg/m2 (normal weight, n = 718; 868 limbs), and >25.0 kg/m2 (overweight/obese, n = 182; 219 limbs). The endpoints were overall survival and freedom from major adverse limb events (MALE).ResultsThe median follow up period was 1.5 years (range: 1 month–8.7 years). The 3 year overall survival rates were 33.3%, 61.2%, and 69.8% in underweight, normal, and overweight/obese patients, respectively. The survival rate was significantly lower in underweight patients and significantly higher in overweight/obese patients compared with patients of normal weight (both p < .0001). The 3 year rates of freedom from MALE did not differ significantly among the three groups (36.4%, 45.4%, and 52.3%, respectively, p = .32). Age, BMI <18.5 kg/m2, heart failure, aortic valve stenosis, renal failure, triglyceride levels, serum albumin <3.0 g/dL, anticoagulant treatment, non-ambulatory status, and Rutherford 6 classification all were significantly associated with overall survival.ConclusionsBMI has a complex correlation with mortality in patients with CLI after EVT for isolated infrapopliteal artery lesions. Underweight patients with CLI have an extremely poor prognosis. Such patients have many other factors associated with mortality, but low BMI was identified as an independent predictor of a poor prognosis in patients with CLI. Similarly, normal weight patients had a small but significant increase in mortality compared with overweight/obese patients

Analysis of ILM Logic Operations via van der Pol Phase Planes

AbstractLogic operations that have previously been numerically demonstrated using intrinsic localized modes (ILMs) in a driven nonlinear 1-D lattice are analyzed using van der Pol phase planes. The time dependent application of a vibrational impurity mode either can produce or destroy an ILM. The appearance or absence of the resulting ILM can be understood via trajectories in the phase plane controlled by the evolving attractors associated with the time dependent impurity mode. Switching between the two possible branches depends on the phase of the amplitude modulation when the impurity mode is removed

Relational power is the new currency of hybrid work

This is the author accepted manuscript. The final version is available from Massachusetts Institute of Technology via the link in this record Traditionally, hierarchies have helped formalize the power structures embedded in different roles within an organization. In a virtual context, the formal hierarchical structure is often less visible than it is in face-to-face environments. In the absence of physical markers of rank and hierarchy, such as office locations, parking spaces, desk labels, badges worn, and so on, managers need to rely on other bases of power to continue to influence and manage employees in technology-mediated settings. Although studies have examined virtual work practices through video-based applications like Zoom and Microsoft Teams, less attention has been paid to text-based platforms such as Slack, Huddle, Ryver, and Flock, among others. Forecasts predict that the market for these collaborative platforms will reach $50.7 billion by 2025. As a result, manager-employee interactions over such platforms are expected to become even more prevalent. We conducted a conceptual study to establish the nature of team relationships in a virtual setting. To empirically ground our findings in how manager-employee relationships are sustained, we analyzed interviews with 64 managers as well as the interactions of nearly 1,200 members of a Fortune 500 multinational firm on the Google+ for Business platform. We found that relational needs play a key role in sustaining manager-employee relationships in virtual environments. The term relational needs refers to the drivers of social exchange between managers and employees. These drivers may include information, task-specific resources, recognition, leadership, and many other factors. Meeting these needs between managers and employees is not necessarily dependent on hierarchical power. Our research revealed that to be successful in the new world of work, managers cannot depend only on hierarchical position as the basis for providing leadership. They must also recognize the role of relational power in hybrid work

Comparative simulation study of colloidal gels and glasses

Using computer simulations, we identify the mechanisms causing aggregation and structural arrest of colloidal suspensions interacting with a short-ranged attraction at moderate and high densities. Two different non-ergodicity transitions are observed. As the density is increased, a glass transition takes place, driven by excluded volume effects. In contrast, at moderate densities, gelation is approached as the strength of the attraction increases. At high density and interaction strength, both transitions merge, and a logarithmic decay in the correlation function is observed. All of these features are correctly predicted by mode coupling theory

Classification of tumours

Tumours are classified according to the most differentiated cells with the exception of carcinomas where a few tumour cells show neuroendocrine differentiation. In this case these cells are regarded as redifferentiated tumour cells, and the tumour is not classified as neuroendocrine. However, it is now clear that normal neuroendocrine cells can divide, and that continuous stimulation of such cells results in tumour formation, which during time becomes increasingly malignant. To understand tumourigenesis, it is of utmost importance to recognize the cell of origin of the tumour since knowledge of the growth regulation of that cell may give information about development and thus possible prevention and prophylaxis of the tumour. It may also have implications for the treatment. The successful treatment of gastrointestinal stromal tumours by a tyrosine kinase inhibitor is an example of the importance of a correct cellular classification of a tumour. In the future tumours should not just be classified as for instance adenocarcinomas of an organ, but more precisely as a carcinoma originating from a certain cell type of that organ

BCAA catabolism in brown fat controls energy homeostasis through SLC25A44.

Branched-chain amino acid (BCAA; valine, leucine and isoleucine) supplementation is often beneficial to energy expenditure; however, increased circulating&nbsp;levels of BCAA are linked to obesity and diabetes. The mechanisms of this paradox remain unclear. Here we report that, on cold exposure, brown adipose tissue (BAT) actively utilizes BCAA in the mitochondria for thermogenesis and promotes systemic BCAA clearance in mice and humans. In turn, a BAT-specific defect in BCAA catabolism attenuates systemic BCAA clearance, BAT fuel oxidation and thermogenesis, leading to diet-induced obesity and glucose intolerance. Mechanistically, active BCAA catabolism in BAT is mediated by SLC25A44, which transports BCAAs into mitochondria. Our results suggest that BAT serves as a key metabolic filter that controls BCAA clearance via SLC25A44, thereby contributing to the improvement of metabolic health