Knowledge of risk factors and their effects is vital for successfully preventing and reducing child neglect. This study provides a meta-analytic update of research on risk factors for child neglect. ...A total of 315 effect sizes were extracted from 36 primary studies and classified into 24 risk domains. Effects of 15 risk domains were significant and ranged from small (r = .110) to large (r = .372) in magnitude. Most risks were found at the parental level, such as having a history of antisocial behavior/criminal offending (r = .372); having a history of mental/psychiatric problems (r = . 259); having mental/physical problems (r = .207); and experiences of abuse in own childhood (r = .182). The effect of mother-related risk factors was not significantly different from the effect of father-related risk factors. It is concluded that child neglect is determined by multiple risk domains and that especially parent-related risk factors are important in preventing and reducing child neglect. Implications of the results for clinical practice are discussed.
In recent years, three unique ReBCO-CORC CICC samples with six-around-one cable layout were developed as technology demonstrators at CERN in collaboration with Advanced Conductor Technologies. The ...tests of these conductors at low temperature in external magnetic field yielded very promising results, but also showed several issues requiring improvement. A new 2.8 m long CORC CICC has been prepared to replace a degraded sample. The voids between CORC strands in the new sample are filled with solder alloy to provide increased mechanical support to the strands, however, this yielded an additional set of new challenges. The conductor has a design critical current of 100 kA at 10 T and 4.5 K and is designed specifically for high-current bus-bars and large detector-type magnets. It therefore features a copper jacket and practical conduction cooling via a cooling line embedded in the jacket.
Circular interpretation of regression coefficients Cremers, Jolien; Mulder, Kees Tim; Klugkist, Irene
British journal of mathematical & statistical psychology,
February 2018, Volume:
71, Issue:
1
Journal Article
Peer reviewed
Open access
The interpretation of the effect of predictors in projected normal regression models is not straight‐forward. The main aim of this paper is to make this interpretation easier such that these models ...can be employed more readily by social scientific researchers. We introduce three new measures: the slope at the inflection point (bc), average slope (AS) and slope at mean (SAM) that help us assess the marginal effect of a predictor in a Bayesian projected normal regression model. The SAM or AS are preferably used in situations where the data for a specific predictor do not lie close to the inflection point of a circular regression curve. In this case bc is an unstable and extrapolated effect. In addition, we outline how the projected normal regression model allows us to distinguish between an effect on the mean and spread of a circular outcome variable. We call these types of effects location and accuracy effects, respectively. The performance of the three new measures and of the methods to distinguish between location and accuracy effects is investigated in a simulation study. We conclude that the new measures and methods to distinguish between accuracy and location effects work well in situations with a clear location effect. In situations where the location effect is not clearly distinguishable from an accuracy effect not all measures work equally well and we recommend the use of the SAM.
Clinical outcome of hyperthermia depends on the achieved target temperature, therefore target conformal heating is essential. Currently, invasive temperature probe measurements are the gold standard ...for temperature monitoring, however, they only provide limited sparse data. In contrast, magnetic resonance thermometry (MRT) provides unique capabilities to non-invasively measure the 3D-temperature. This study investigates MRT accuracy for MR-hyperthermia hybrid systems located at five European institutions while heating a centric or eccentric target in anthropomorphic phantoms with pelvic and spine structures. Scatter plots, root mean square error (RMSE) and Bland-Altman analysis were used to quantify accuracy of MRT compared to high resistance thermistor probe measurements. For all institutions, a linear relation between MRT and thermistor probes measurements was found with
(mean ± standard deviation) of 0.97 ± 0.03 and 0.97 ± 0.02, respectively for centric and eccentric heating targets. The RMSE was found to be 0.52 ± 0.31 °C and 0.30 ± 0.20 °C, respectively. The Bland-Altman evaluation showed a mean difference of 0.46 ± 0.20 °C and 0.13 ± 0.08 °C, respectively. This first multi-institutional evaluation of MR-hyperthermia hybrid systems indicates comparable device performance and good agreement between MRT and thermistor probes measurements. This forms the basis to standardize treatments in multi-institution studies of MR-guided hyperthermia and to elucidate thermal dose-effect relations.
An investigation is performed on the quench behavior of a conceptual 50-GJ 8-T high-temperature-superconductor-based solenoid. In this design, a 50-kA conductor-on-round-core cable-in-conduit ...conductor utilizing ReBCO technology is envisioned, operating at 40 K. Various properties such as resistivity, thermal conductivity, and heat capacity are very different at this temperature, which affects the quench behavior. It is found that the envisioned conductor is very stable with a minimum quench energy of about 2 kJ. However, the quench propagation velocity is typically about 20 mm/s, so that creating a wide-spread normal zone throughout the coil is very challenging. Moreover, an extraction voltage exceeding 20 kV would be required to ensure a hot-spot temperature below 100 K once a thermal runaway occurs. A novel concept dubbed "rapid quench transformation" is proposed whereby the superconducting conductor is co-wound with a normal conductor to achieve a high degree of inductive coupling. This geometry allows for a significant electric noise reduction, thus enabling low-threshold quench detection. The secondary circuit is connected in series with a stack of diodes, not allowing current transfer during regular operation, but very fast current transfer once a quench is detected. With this approach, the hot-spot temperature can be kept within 20 K of the cold mass temperature at all times, the hot-spot temperature is well below 100 K, and just under 80% of the stored energy can be extracted during a quench.
No-Insulation (NI) technology for HTS coils has been around for a decade and is a proven method to protect small pancake coils in case of a quench. Without turn-to-turn insulation, excess current can ...bypass a sudden resistive part, thereby possibly preventing damaging the conductor locally. Unfortunately, having a very low turn-to-turn insulation does not automatically translate into coil protection when the magnets are larger and their coil energy density reaches values in the order of tens of kJ/kg. During a quench of such magnets, the quench propagation behavior is often driven by electromagnetic diffusion due to inductive effects, rather than thermal diffusion. This may locally increase the current and energy density far above nominal values and thereby also increase the Lorentz force density locally on the conductor. In that case, a coil's mechanical and thermal limits become a much more stringent factor in the survival of such coils and thus force, stress and temperature management and the possible addition of an active quench protection system are a key component in their design. In this paper a new active quench protection concept is proposed for high-field HTS solenoids that comprise a stack of many NI pancake coils. This protection concept is based on a capacitor discharge into the NI magnet and offers a fast and homogeneous superconducting to normal state transition of the entire coil without the need for any additional internal components, which makes it a very robust protection system.
An open-source Finite Element Quench Simulator (FiQuS) is being developed as part of the STEAM framework following CERN's open science policy 1. The tool is based solely on open-source software and ...uses Python to generate geometries and meshes with Gmsh, and compute solutions with GetDP. FiQuS scripts have a modular structure in order to accommodate a broad range of geometries and simulation requirements with the main focus on superconducting accelerator magnets. The tool, at its advanced stage, will be capable of 1D, 2D, and 3D geometry generation of superconducting elements such as bus bars, multi-pole, solenoid, and canted-cos-theta (CCT) magnets. It already has the capability for parametrized mesh control and subsequent model generation of 2D multi-pole and 3D CCT magnets. It will be possible to perform either electromagnetic (EM), thermal (TH), or coupled EM-TH simulations for static or transient analysis. The focus is on aspects related to the powering and quench transients, enabling parametric analyses and co-simulations to support comprehensive quench protection studies. In this contribution, we lay the foundation of FiQuS by presenting its structure and three specific capabilities that represent the basis upon which the future modules will be built. These capabilities showcase the integration of FiQuS with software developed at CERN, at other national laboratories, and within the STEAM framework. The first capability is the integration with the STEAM framework, which enables cooperative simulations with the other tools of the framework, the automatization of multi-step studies, and the Single Source Of Truth (SSOT) practice through the centralization of model and material data. The second capability is the integration with the magnet design software ROXIE via a dedicated input files parser, which seamlessly integrates magnet design details around a single input file. Examples of magnetostatic solutions obtained in FiQuS are shown for the 2D cross-section of LHC magnets based on ROXIE input files. The third capability is the integration with the parametric analysis software Dakota developed by Sandia National Laboratories. An example is shown of multi-objective optimization of the model mesh to minimize the error of the computed magnetic field.
The next generation of Nb <inline-formula><tex-math notation="LaTeX">_{3}</tex-math></inline-formula> Sn accelerator magnets are pushed to higher magnetic fields, higher stored energy and higher ...energy density. This brings additional challenges when it comes to quench protection. At CERN, a fast quench protection system is under development that introduces normal zones directly in the coil's conductor by inductive heating. This system is called External coil Coupled Loss Induced Quench (E-CLIQ). The E-CLIQ device comprises many small copper coils that are strategically placed near the main coils. Once a quench is detected, a capacitor is discharged in to the E-CLIQ coils, resulting in the characteristic damped oscillating current of an RLC circuit. This results in a large, but local applied dB/dt on the conductor of the main magnet system, which locally heats it by induced interfilament and interstrand coupling loss. Such a system has the advantage of being fast by introducing normal zones in potentially less than 10 ms, it doesn't rely on heat flow through the insulation layers of the coil, as is the case with traditional quench heaters, and it is not electrically connected to the main circuit. In this paper, the E-CLIQ system is introduced, several first demonstrator coils are presented and the results of a first proof-of-concept test are shown.
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