Shrinkage and restrained shrinkage cracking of self-compacting concrete compared to conventionally vibrated concrete

Self-compacting concrete (SCC) used in Switzerland contains about 80l/m3 more volume of paste than conventionally vibrated concrete (CVC). Consequently, there are some systematic differences in the properties of the hardened concrete. Normally, shrinkage of SCC is higher than shrinkage of CVC. Therefore, risk of cracking in case of restrained deformations can be increased for SCC. In this study shrinkage of thirteen different SCC mixtures using volume of paste, water content, type of binder, grain size distribution or content of shrinkage reducing admixture (SRA) as variables was compared with shrinkage of three different CVC mixtures with constant volume of paste but variable w/b. Furthermore, the risk of cracking of the different SCC- and CVC-mixtures in restrained conditions was studied under constant and varying curing conditions. The results show that shrinkage is mainly depending on volume of paste. Due to the higher volume of paste, SCC displayed higher shrinkage than CVC. Adding an SRA was the only measure to reduce shrinkage of SCC to values of CVC. Restrained shrinkage cracking is depending on shrinkage rate, mechanical properties and drying velocity. For slow shrinkage stress development, cracking risk of SCC can be lower compared to CVC despite the higher shrinkage rat

Growth of Single Unit-Cell Superconducting La2−x_{2-x}Srx_xCuO4_{4} Films

We have developed an approach to grow high quality ultrathin films of La$_{2-x}$Sr$_x$CuO$_{4}$ with molecular beam epitaxy, by adding a homoepitaxial buffer layer in order to minimize the degradation of the film structure at the interface. The advantage of this method is to enable a further reduction of the minimal thickness of a superconducting La$_{1.9}$Sr$_{0.1}$CuO$_{4}$ film. The main result of our work is that a single unit cell (only two copper oxide planes) grown on a SrLaAlO$_4$ substrate exhibits a superconducting transition at 12.5 K (zero resistance) and an in-plane magnetic penetration depth $\lambda_{ab}(0)$ = 535 nm.Comment: to be published in "Solid State Electonics" special issue, conference proceedings of the 9th Workshop on Oxide Electronics, St-Pete Beach, FL, 20-23 november 2002 : 12 pages 4 figures in preprint versio

Barbados

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Spin-Correlation Coefficients and Phase-Shift Analysis for p+3^3He Elastic Scattering

Angular Distributions for the target spin-dependent observables A$_{0y}$, A$_{xx}$, and A$_{yy}$ have been measured using polarized proton beams at several energies between 2 and 6 MeV and a spin-exchange optical pumping polarized $^3$He target. These measurements have been included in a global phase-shift analysis following that of George and Knutson, who reported two best-fit phase-shift solutions to the previous global p+$^3$He elastic scattering database below 12 MeV. These new measurements, along with measurements of cross-section and beam-analyzing power made over a similar energy range by Fisher \textit{et al.}, allowed a single, unique solution to be obtained. The new measurements and phase-shifts are compared with theoretical calculations using realistic nucleon-nucleon potential models.Comment: Submitted to Phys. Rev.

The role of age and digital competence on the use of online health and social care services : A cross-sectional population-based survey

Objective Online health and social care services are getting widespread which increases the risk that less advantaged groups may not be able to access these services resulting in digital exclusion. We examined the combined effects of age and digital competence on the use of online health and social care services. Methods We used a large representative population-based sample of 4495 respondents from Finland. Paper-based self-assessment questionnaire with an online response option was mailed to participants. The associations were analyzed using survey weighted logistic regression, exploring potential non-linear effects of age and controlling for potential sex differences. Results Higher age, starting from around the age of 60 was associated with a lower likelihood of using online services for receiving test results, renewing prescriptions and scheduling appointments. Good digital competence was able to hinder the age-related decline in online services use, but only up to around the age of 80. Conclusions Our results suggest that older adults are at risk of digital exclusion, and not even good digital competence alleviates this risk among the oldest. We suggest that health and social care providers should consider older users' needs and abilities more thoroughly and offer easy to use online services. More digital support and training possibilities should be provided for older people. It is equally important that face-to-face and telephone services will be continued to be provided for those older people who are not able to use online services even when supported.Peer reviewe

Sussex by the sea: a descriptive analysis of dialect variation in the South East of England based on English Dialect App data

Dialects in the South East of England are very often perceived as one homogenous mass, without much regional variation. Rosewarne introduced the notion of Estuary English and defined it as ‘variety of modified regional speech [ . . . ] a mixture of non-regional and local south-eastern English pronunciation and intonation’ (Rosewarne, 1984). However, studies such as Przedlacka (2001) and Torgersen & Kerswill (2004) have shown that, at least on the phonetic level, distinct varieties exist. Nevertheless, very few studies have investigated language use in the South East and even fewer in the county of Sussex. It is often claimed that there is no distinct Sussex dialect (Coates, 2010: 29). Even in the earliest works describing the dialect of the area (Wright, 1903) there are suggestions that it cannot be distinguished from Hampshire in the west and Kent in the east

Demonstration of Machine Learning-Based Model-Independent Stabilization of Source Properties in Synchrotron Light Sources.

Synchrotron light sources, arguably among the most powerful tools of modern scientific discovery, are presently undergoing a major transformation to provide orders of magnitude higher brightness and transverse coherence enabling the most demanding experiments. In these experiments, overall source stability will soon be limited by achievable levels of electron beam size stability, presently on the order of several microns, which is still 1-2 orders of magnitude larger than already demonstrated stability of source position and current. Until now source size stabilization has been achieved through corrections based on a combination of static predetermined physics models and lengthy calibration measurements, periodically repeated to counteract drift in the accelerator and instrumentation. We now demonstrate for the first time how the application of machine learning allows for a physics- and model-independent stabilization of source size relying only on previously existing instrumentation. Such feed-forward correction based on a neural network that can be continuously online retrained achieves source size stability as low as 0.2  μm (0.4%) rms, which results in overall source stability approaching the subpercent noise floor of the most sensitive experiments

Use of electronic patient records and encrypted email patient communication among Swiss chiropractors: a population-based cross-sectional study

BACKGROUND The implementation of electronic health information technologies is a key target for healthcare quality improvement. Among Swiss chiropractors, reliable data on the use of electronic heath information technologies and distribution of the health workforce was lacking. OBJECTIVES To estimate the prevalence of electronic patient record (EPR) and encrypted email communication use among Swiss chiropractors and describe the geographic distribution of chiropractors in Switzerland. METHODS Population-based cross-sectional study of all active practising members of the Swiss Chiropractic Association (ChiroSuisse) between 3 December 2019 and 31 January 2020. We asked about clinician and practice characteristics, EPR use for clinical record keeping, use of encrypted email for patient communication, and information on EPR and encrypted email communication products used. Multivariable logistic regression analyses assessed the associations between clinician and practice characteristics and (1) EPR use, and (2) encrypted email use. RESULTS Among 286 eligible Swiss chiropractors (193 [68%] men; mean age, 51.4 [SD, 11.2] years), 217 (76%) completed the survey (140 [65%] men; mean age 50.7 [11.2] years). Among respondents, 47% (95% confidence interval [CI], 40-54%) reported using an EPR in their practice, while 60% (95% CI, 54-67%) endorsed using encrypted email technology. Chiropractors aged ≥ 60 (versus those ≤ 39) years were 74% less likely to use an EPR system (OR 0.26, 95% CI 0.08 to 0.77), while clinicians from practices with 4 or more chiropractors (versus those from solo practices) were over 5 times more likely to report EPR use (OR 5.6, 2.1 to 16.5). Findings for factors associated with encrypted email use were similar. The density of chiropractors in Switzerland was 3.3 per 100,000 inhabitants. CONCLUSIONS As of January 2020, 286 duly licensed chiropractors were available to provide musculoskeletal healthcare in Switzerland - just under 50% of responding Swiss chiropractors used an EPR system in clinical practice, while 60% used encrypted email technology. Better implementation of EPR and electronic health information technologies in Swiss chiropractic practice is possible and encouraged for the purpose of musculoskeletal healthcare quality improvement

Longitudinal phase space manipulation in energy recovering linac-driven free-electron lasers

Energy recovering an electron beam after it has participated in a free-electron laser (FEL) interaction can be quite challenging because of the substantial FEL-induced energy spread and the energy anti-damping that occurs during deceleration. In the Jefferson Lab infrared FEL driver-accelerator, such an energy recovery scheme was implemented by properly matching the longitudinal phase space throughout the recirculation transport by employing the so-called energy compression scheme. In the present paper,after presenting a single-particle dynamics approach of the method used to energy-recover the electron beam, we report on experimental validation of the method obtained by measurements of the so-called "compression efficiency" and "momentum compaction" lattice transfer maps at different locations in the recirculation transport line. We also compare these measurements with numerical tracking simulations.Comment: 31 pages, 13 figures, submitted to Phys. Rev. Special Topics A&