Friction factors for smooth pipe flow

Friction factor data from two recent pipe flow experiments are combined to provide a comprehensive picture of the friction factor variation for Reynolds numbers from 10 to 36,000,000

On the origin of the extremely different solubilities of polyethers in water

The solubilities of polyethers are surprisingly counter-intuitive. The best-known example is the difference between polyethylene glycol ([–CH2–CH2–O–]n) which is infinitely soluble, and polyoxymethylene ([–CH2–O–]n) which is completely insoluble in water, exactly the opposite of what one expects from the C/O ratios of these molecules. Similar anomalies exist for oligomeric and cyclic polyethers. To solve this apparent mystery, we use femtosecond vibrational and GHz dielectric spectroscopy with complementary ab initio calculations and molecular dynamics simulations. We find that the dynamics of water molecules solvating polyethers is fundamentally different depending on their C/O composition. The ab initio calculations and simulations show that this is not because of steric effects (as is commonly believed), but because the partial charge on the O atoms depends on the number of C atoms by which they are separated. Our results thus show that inductive effects can have a major impact on aqueous solubilities

Presurgical diagnosis of diffuse gliomas in adults:Post-WHO 2021 practical perspectives from radiologists in neuro-oncology units

The 2021 World Health Organization classification of CNS tumours was greeted with enthusiasm as well as an initial potential overwhelm. However, with time and experience, our understanding of its key aspects has notably improved. Using our collective expertise gained in neuro-oncology units in hospitals in different countries, we have compiled a practical guide for radiologists that clarifies the classification criteria for diffuse gliomas in adults. Its format is clear and concise to facilitate its incorporation into everyday clinical practice. The document includes a historical overview of the classifications and highlights the most important recent additions. It describes the main types in detail with an emphasis on their appearance on imaging. The authors also address the most debated issues in recent years. It will better prepare radiologists to conduct accurate presurgical diagnoses and collaborate effectively in clinical decision making, thus impacting decisions on treatment, prognosis, and overall patient care.</p

Neutron Radiation Damage In Silicon Transistors

In the investigation of base and collector current as a function of the emitter-to-base voltage, previous studies have shown that neutron-induced base current has components originating in the emitter space charge region as well as the neutral base region. This study shows that while the low injection level neutron-induced base current is dominated by the space charge component, the high injection behavior appears to be controlled by recombination in the neutral base region. Additional experiments performed in special tetrode transistors and van der Pauw-type samples indicate that changes in collector current are dominated by recombination in the neutral base, while changes in base doping and mobility have only a secondary effect. These conclusions are reached from experiments on transistors with a ring emitter, on tetrode-type test transistors, and on special Hall-effect devices, and by a detailed analysis of the emission crowding characteristics of a ring-dot geometry device. Copyright © 1968 by The Institute of Electrical and Electronics Engineers, Inc

Presurgical diagnosis of diffuse gliomas in adults:Post-WHO 2021 practical perspectives from radiologists in neuro-oncology units

The 2021 World Health Organization classification of CNS tumours was greeted with enthusiasm as well as an initial potential overwhelm. However, with time and experience, our understanding of its key aspects has notably improved. Using our collective expertise gained in neuro-oncology units in hospitals in different countries, we have compiled a practical guide for radiologists that clarifies the classification criteria for diffuse gliomas in adults. Its format is clear and concise to facilitate its incorporation into everyday clinical practice. The document includes a historical overview of the classifications and highlights the most important recent additions. It describes the main types in detail with an emphasis on their appearance on imaging. The authors also address the most debated issues in recent years. It will better prepare radiologists to conduct accurate presurgical diagnoses and collaborate effectively in clinical decision making, thus impacting decisions on treatment, prognosis, and overall patient care.</p

Effectiveness of Neuromotor Task Training for Children with Developmental Coordination Disorder: A Pilot Study

The aim of this pilot study was to evaluate the effectiveness of a Neuromotor Task Training (NTT), recently developed for the treatment of children with Developmental Coordination Disorder (DCD) by pediatric physical therapists in the Netherlands. NTT is a task-oriented treatment program based upon recent insights from motor control and motor learning research. Ten children with DCD (intervention group) were tested before and after 9 and 18 treatment sessions on the Movement ABC and a dysgraphia scale in order to measure the effectiveness of treatment on gross and fine motor skills in general and handwriting in particular. Five children (no-treatment control group) were tested twice with a time lag of nine weeks on the Movement ABC in order to measure spontaneous improvement. No improvement was measured for the children in the notreatment control group, whereas a significant improvement was found for children in the intervention group for both quality of handwriting and performance on the Movement ABC after 18 treatment sessions

Improving Predictions for Helium Emission Lines

We have combined the detailed He I recombination model of Smits with the collisional transitions of Sawey & Berrington in order to produce new accurate helium emissivities that include the effects of collisional excitation from both the 2 (3)S and 2 (1) S levels. We present a grid of emissivities for a range of temperature and densities along with analytical fits and error estimates. Fits accurate to within 1% are given for the emissivities of the brightest lines over a restricted range for estimates of primordial helium abundance. We characterize the analysis uncertainties associated with uncertainties in temperature, density, fitting functions, and input atomic data. We estimate that atomic data uncertainties alone may limit abundance estimates to an accuracy of 1.5%; systematic errors may be greater than this. This analysis uncertainty must be incorporated when attempting to make high accuracy estimates of the helium abundance. For example, in recent determinations of the primordial helium abundance, uncertainties in the input atomic data have been neglected.Comment: ApJ, accepte

A retrospective analysis of injury risk in physical education teacher education students between 2000-2014

To identify primary target groups for injury prevention in physical education teacher education (PETE) students, risk differences between subgroups by sex and curriculum years were compared in a retrospective cohort study (2000-2014). Injuries recorded by healthcare professionals at the medical facility of a Dutch PETE college were used to calculate overall, intra- and extracurricular injury prevalence per sex, curriculum years, and semesters and to compare these by logistic regression analyses. Of 1083 PETE students, 599 (55.3%) reported at least one injury during their curriculum (60.0% intracurricular). Female students had a higher risk for overall (OR 2.29, 95%CI 1.77-2.96) and for intracurricular injuries (OR 3.12, 95%CI 2.41-4.03), but not for extracurricular injuries. Compared to the freshman year, injury risk dropped during the consecutive years (OR 0.56, 95%CI 0.46-0.67; OR 0.33, 95%CI 0.27-0.41; OR 0.04, 95%CI 0.03-0.07, respectively). The first semesters of the freshman and second year showed higher injury prevalence compared to two out of three consecutive semesters (P < .006). Primary target groups for injury preventive measures are freshman and female PETE students. Factors contributing to the predominantly higher intracurricular injury risks, most notably in female students, need to be investigated in prospective cohort studies, regardless of sex

T-cell responses in oiled guillemots and swans in a rehabilitation setting

This article has been accepted for publication in the Archives of Environmental Contamination and Toxicology. The final version can be accessed from the link below.This article has been made available through the Brunel Open Access Publishing Fund.Aquatic birds are commonly affected by oil spills. Despite rehabilitation efforts, the majority of rehabilitated common guillemots (Uria aalge) do not survive, whereas mute swans (Cygnus olor) tend to have higher post-release survival. Polyaromatic hydrocarbons (PAHs) present in crude oil and diesel are immunotoxic in birds affecting cell-mediated responses to immunogens. Because it is a target of PAH toxicity, T-lymphocyte response to controlled mitogen administration (phytohemagglutinnin test) was investigated in a scoping study as a potentially useful minimally invasive in vivo test of cell-mediated immunity. The test was performed on 69 mute swans and 31 common guillemots stranded on the Norfolk and Lincolnshire coastline and inland waterways in England (UK)either due to injury or to contamination with crude or diesel oil. T-lymphocyte response was significantly decreased in swans with greater oil scores. T-lymphocyte responses were also decreased in guillemots, but this finding was not statistically significant