Measuring shell resonances of spherical acoustic resonators

International audienceCoupling between gas and shell is a concern in the experiment used at LNE-CNAM to determine the Boltzmann constant kB by an acoustic method. As the walls of real resonators are not perfectly ridig, some perturbations occur in the frequency range of the acoustic resonances measured within helium gas contained in the caivity. As a contribution for a better understanding of the phenomenon, we have built an experiment to measure the shell modes of the spherical resonators in use in our laboratory. We report here a work in progress to assess these modes using a hammer blow method together with modal analysis. The study is carried out with air-filled, copper-walled, half-litre quasi-spherical resonator in the frequency range from 1 Hz to 20 kHz. Our results show that the shell modes expand into multiple resonances of similar modal shape, including the "breathing" mode. We confirm the observations reported in other works [4,6] of shell perturbations at other frequencies than the breathing frequency

Physician Time Management

Introduction: Time management is an essential skill set for physicians. The importance of time management is not routinely emphasized in undergraduate or graduate medical education curricula, often resulting in the development of poor time-management practices early in training. Improving time-management practices may lead to decreased stress, increased productivity, and improved well-being for physicians. Methods: This interactive workshop targeted trainees and junior faculty. It aimed to highlight common physician knowledge gaps with respect to cognitive limitations and to teach effective time-management strategies. It also aimed to educate learners about how time management may increase physician career satisfaction. The workshop included a detailed presentation with structured resources to reinforce skill development. Results: This workshop was given four times to 54 residents in two different training paradigms. Evaluations were based on a 4-point Likert scale (1 = Strongly Disagree, 4 = Strongly Agree). Overall, participants indicated that the workshop addressed an educational need (M = 3.72) and would recommend this workshop to a colleague (M = 3.83). Follow-up survey results at 4 months indicated that most workshop participants had noticed some degree of improved productivity and well-being, that only a small minority had not incorporated new elements of time management into routine practices. Discussion: This workshop offers an effective way to teach time-management strategies to physicians. Our results imply that this workshop meets an early career physician need by addressing a necessary skill set. Effective time-management skills may promote physician career sustainability

Determination of the Boltzmann constant k from the speed of sound in helium gas at the triple point of water

partially_open6The Boltzmann constant k has been determined from a measurement of the speed of sound in helium gas in a quasi-spherical resonator (volume 0.5 l) maintained at a temperature close to the triple point of water (273.16 K). The acoustic velocity c is deduced from measured acoustic resonance frequencies and the dimensions of the quasi-sphere, the latter being obtained via simultaneous microwave resonance. Values of c are extrapolated to the zero pressure limit of ideal gas behaviour. We find J⋅K−1, a result consistent with previous measurements in our group and elsewhere. The value for k, which has a relative standard uncertainty of 1.02 ppm, lies 0.02 ppm below that of the CODATA 2010 adjustment.mixedPitre, L; Risegari, L; Sparasci, F; Plimmer, M D; Himbert, M E; Giuliano Albo, P APitre, L; Risegari, L; Sparasci, F; Plimmer, M D; Himbert, M E; Giuliano Albo, P

Toward the realization of a primary low-pressure standard using a superconducting microwave resonator

We describe a primary gas pressure standard based on the measurement of the refractive index of helium gas using a microwave resonant cavity in the range between 500 Pa and 20 kPa. To operate in this range, the sensitivity of the microwave refractive gas manometer (MRGM) to low-pressure variations is substantially enhanced by a niobium coating of the resonator surface, which becomes superconducting at temperatures below 9 K, allowing one to achieve a frequency resolution of about 0.3 Hz at 5.2 GHz, corresponding to a pressure resolution below 3 mPa at 20 Pa. The determination of helium pressure requires precise thermometry but is favored by the remarkable accuracy achieved by ab initio calculations of the thermodynamic and electromagnetic properties of the gas. The overall standard uncertainty of the MRGM is estimated to be of the order of 0.04%, corresponding to 0.2 Pa at 500 and 8.1 Pa at 20 kPa, with major contributions from thermometry and the repeatability of microwave frequency measurements. A direct comparison of the pressures realized by the MRGM with the reference provided by a traceable quartz transducer shows relative pressure differences between 0.025% at 20 kPa and -1.4% at 500 Pa. (c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

Quality assurance and assessment frameworks of biosystems engineering studies

Regulatory instruments at the national level to ensure high quality are crucial to achieve and maintain a regional hub of higher education in Malta. While The Malta Qualifications Council and the National Commission for Higher Education are established and operational, the legal framework to set up a quality assurance agency and a quality assurance and licensing framework is in place, but the legislations is still awaiting approval. The University of Malta has set up internal quality assurance structures, The Programme Validation Committee monitors, reviews and recommends programmes for approval by Senate, The formation of the INSTITUTE OF EARTH SYSTEMS will facilitate the means through which a Bio Systems Engineering course could be offered, Furthermore the recent establishment of a Maltese Chamber of Agrologists could in theory eventually take up the role to grant professional accreditation,peer-reviewe

Functional classification of proteins based on projection of amino acid sequences: application for prediction of protein kinase substrates

<p>Abstract</p> <p>Background</p> <p>The knowledge about proteins with specific interaction capacity to the protein partners is very important for the modeling of cell signaling networks. However, the experimentally-derived data are sufficiently not complete for the reconstruction of signaling pathways. This problem can be solved by the network enrichment with predicted protein interactions. The previously published <it>in silico </it>method PAAS was applied for prediction of interactions between protein kinases and their substrates.</p> <p>Results</p> <p>We used the method for recognition of the protein classes defined by the interaction with the same protein partners. 1021 protein kinase substrates classified by 45 kinases were extracted from the Phospho.ELM database and used as a training set. The reasonable accuracy of prediction calculated by leave-one-out cross validation procedure was observed in the majority of kinase-specificity classes. The random multiple splitting of the studied set onto the test and training set had also led to satisfactory results. The kinase substrate specificity for 186 proteins extracted from TRANSPATH^®database was predicted by PAAS method. Several kinase-substrate interactions described in this database were correctly predicted. Using the previously developed ExPlain™ system for the reconstruction of signal transduction pathways, we showed that addition of the newly predicted interactions enabled us to find the possible path between signal trigger, TNF-alpha, and its target genes in the cell.</p> <p>Conclusions</p> <p>It was shown that the predictions of protein kinase substrates by PAAS were suitable for the enrichment of signaling pathway networks and identification of the novel signaling pathways. The on-line version of PAAS for prediction of protein kinase substrates is freely available at <url>http://www.ibmc.msk.ru/PAAS/</url>.</p