An Investigation into the Effects of Classroom Acoustics on Teachers’ Voices

The acoustic design of classrooms has traditionally focused on pupils hearing the teacher. There is a need for guidance on the consideration of voice ergonomics for teachers in classroom design. This project undertook measurements of teachers’ voices in classrooms with different acoustic properties to examine possible relationships between voice parameters and classroom acoustics. The mean voice level measured was classified as ‘loud’ (based on guidance values) and the participants spoke for a large proportion of the day (average 21%). Those teaching in rooms with higher unoccupied noise levels spoke with a higher sound level. There was a significant, moderate, positive correlation between voice levels in female participants and the unoccupied noise levels in the same region of the noise spectrum as the fundamental frequency of the female voice. There were signs of a similar relationship for male participants. This indicated that the control of low frequency noise levels and reverberation times (not currently covered by schools guidance documents in England) may be important in reducing voice levels and the associated vocal risks. An online survey was also undertaken which gathered 153 responses and included questions on voice problems, voice training, classroom acoustics and general health. The respondents reported a number of interesting findings. 66% reported having experienced voice problems, with many continuing to work despite these problems. A relatively small proportion of respondents had received voice training (41%), and many reported shouting or raising their voice. There were greater rates of reported voice problems in teachers of young children and those teaching in open plan classrooms. Subjectively the main acoustic issues for teachers were inadequate internal sound insulation and excessive reverberation. External noise intrusion was not reported as significant

Surface Subsidence Over Deep Solution Mined Storage Cavern Field

Ten years observation by GDF on Tersanne solution-mined gas storage field, offers the opportunity for a mechanical interpretation of the surface subsidence. According to the geological context, the rockmass was modellised by a two-layered medium with highly contrasted mechanical behavior: a soft elastic clay cover, and a viscous salt mass. Given the field uncertainties, mostly related to the cover layer, and the three- dimensional nature of the problem, indirect methods were used to obtain bounds for the surface subsidence evolution and a parametric study was performed. Comparison with data of the field allows to determine likely rock mass parameters, put forward some typical mechanical response, and give some insight on the trends of the subsidence phenomena

Does consciousness exist independently of present time and present time independently of consciousness

International audienceWhile some are currently debating whether time may or may not be an illusion, others keep devoting their time to the science of consciousness. Time as such may be seen as a physical or a subjective variable, and the limitations in our capacity of perceiving and analyzing temporal order and change in physical events definitely constrain our understanding of consciousness which, in return, constrains our conceptual under-standing of time. Temporal codes generated in the brain have been considered as the key to insight into neural function and, ultimately, as potential neural substrates of consciousness itself. On the basis of cur-rent evidence and opinion from neuroscience and philosophy, we consider the interrelation between con-sciousness and time in the light of Hegel and Heidegger's concepts of Sein (Being) and Zeit (Time). We suggest that consciousness can be defined in terms of a succession of psychological moments where we realize that we exist in, and are part of, a present moment in time. This definition places all other percep-tual or sensorial processes which may characterize phenomenal experience at a different level of analysis and centers the debate around consciousness on the fundamental identity link between awareness of the Ich (I) and awareness of what Heidegger termed Ursprüngliche Zeit (original time). We argue that human consciousness has evolved from the ability to be aware of, to remember, and to predict temporal order and change in nature, and that the limits of this capacity are determined by limits in the functional plasticity of resonant brain mechanisms. Although the conscious state of the Self is the ultimate expression of this evolution, it is devoid of any adaptive function as such

Une mesure de la perméabilité et du fluage d'une caverne dans le sel

Rock mass properties diff er significanùy from those measured on sam pies in the laboratory. A test has been performed on a deep brine-fi.lled ca vern, with the objective of measuring the equilibrium pressure reached when the ca vern was closed. Such an equilibrium is reached when salt mass creep, which leads to cavern shrinkage, balances brine permeation through the ca vern wall. A K = 2·10-19 m 2 value of the average in situ intrinsic permeability has been deduced from the test; it is significantly higher than the intrinsic permeability measured in a weil or in the laboratory. This result supports ca vern abandonment scenarios in which the risk of natural fracturation due to high brine pressures is alleviated.Les propriétés d'un massif rocheux sont en général différentes de celles mesurées au laboratoire sur un échantillon. On a cherché la pression d'équilibre à laquelle se stabilise la saumure contenue dans une cavité souterraine profonde fermée. Cet équilibre résulte de l'action du fluage du massif, qui tend à refermer la cavité, et de la perméation de la saumure à travers les parois de la cavité. On déduit de la valeur d'équilibre mesurée une perméabilité intrinsèque moyenne de l'ordre de $K = 2·10^{-19}\text{m}^2$, sensiblement plus forte que les valeurs estimées antérieurement sur des échantillons ou dans un puits. Ce résultat permet de construire un scénario du comportement de la caverne après abandon, qui exclut le risque de fracturation naturelle

Island invasives: scaling up to meet the challenge

Management and eradication techniques for invasive alien birds remain in their infancy compared to invasive mammal control methods, and there are still relatively few examples of successful avian eradications. Since 2011, five separate eradication programmes for invasive birds have been conducted on three islands by the Seychelles Islands Foundation (SIF). Target species were prioritised according to their threat level to the native biodiversity of the UNESCO World Heritage Sites of the Seychelles, Aldabra Atoll and Vallée de Mai, which SIF is responsible for managing and protecting. Red-whiskered bulbuls (Pycnonotus jocosus) and Madagascar fodies (Foudia madagascariensis) occurred on Assumption, the closest island to Aldabra, which, at the time, had no known introduced bird species. The growing population of ring-necked parakeets (Psittacula krameri) on Mahé posed a threat to endemic Seychelles black parrots (Coracopsis barklyi) on Praslin where the Vallée de Mai forms their core breeding habitat. In 2012, red-whiskered bulbuls and Madagascar fodies were detected on Aldabra, so an additional eradication was started. All eradications used a combination of mist-netting and shooting. The intensive part of each eradication lasted three years or less. On Assumption, 5,279 red-whiskered bulbuls and 3,291 Madagascar fodies were culled; on Mahé, 545 parakeets were culled; and on Aldabra 262 Madagascar fodies and one red-whiskered bulbul were culled. Each programme underwent 1–2 years of follow-up monitoring before eradication was confirmed, and four of the five eradications have been successful so far. None of these species had previously been eradicated in large numbers from other islands so the successes substantially advance this field of invasive species management. The challenges and insights of these eradications also provide unique learning opportunities for other invasive avian eradications

Collisional kinetics of non-uniform electric field, low-pressure, direct-current discharges in H2_{2}

A model of the collisional kinetics of energetic hydrogen atoms, molecules, and ions in pure H$_2$ discharges is used to predict H$_\alpha$ emission profiles and spatial distributions of emission from the cathode regions of low-pressure, weakly-ionized discharges for comparison with a wide variety of experiments. Positive and negative ion energy distributions are also predicted. The model developed for spatially uniform electric fields and current densities less than $10^{-3}$ A/m$^2$ is extended to non-uniform electric fields, current densities of $10^{3}$ A/m$^2$, and electric field to gas density ratios $E/N = 1.3$ MTd at 0.002 to 5 Torr pressure. (1 Td = $10^{-21}$ V m$^2$ and 1 Torr = 133 Pa) The observed far-wing Doppler broadening and spatial distribution of the H$_\alpha$ emission is consistent with reactions among H$^+$, H$_2^+$, H$_3^+$, and H$^-H$ ions, fast H atoms, and fast H$_2$ molecules, and with reflection, excitation, and attachment to fast H atoms at surfaces. The H$_\alpha$ excitation and H$^-$ formation occur principally by collisions of fast H, fast H$_2$, and H$^+$ with H$_2$. Simplifications include using a one-dimensional geometry, a multi-beam transport model, and the average cathode-fall electric field. The H$_\alpha$ emission is linear with current density over eight orders of magnitude. The calculated ion energy distributions agree satisfactorily with experiment for H$_2^+$ and H$_3^+$, but are only in qualitative agreement for H$^+$ and H$^-$. The experiments successfully modeled range from short-gap, parallel-plane glow discharges to beam-like, electrostatic-confinement discharges.Comment: Submitted to Plasmas Sources Science and Technology 8/18/201

Research and dissemination 2019:Aalborg University

AAU fik ny forskningsportal i 2019. Vbn.aau.dk trækker data fra Pure som hidtil, men formidlingen af forskning fra AAU har fået flere facetter. Det er ikke længere blot publikationer, aktiviteter og presseklip, der vises, men også impact, udstyr, priser, bevillinger og datasæt. Og så er der ikke kun vægt på ”Output” – også ”Outcome” er blevet en del af visningen, idet SoMe metrikker og citationer vises for publikationer. Profilering af AAU, institutter, forskningsgrupper og den enkelte forsker har dermed fået en platform med flere muligheder end hidtil.VBN Årsplakaten viser dig highlights fra året der gik!AAU have a new research portal from 2019. Vbn.aau.dk pulls data from Pure as so it used to be, but the dissemination of research from AAU has gained several new facets. It is no longer just publications, activities and press clippings that are displayed, but also impact, equipment, prices, grants and data sets. And not only is there an emphasis on "output" - "outcome" has also become part of the portal, with SoMe metrics and citations appearing for publications. Profile pages for AAU, institutes, research groups and the individual researcher has thus been given a platform with more opportunities than before.The VBN Annual Poster shows you highlights from the past year