591 research outputs found
Analysis of a single-mode waveguide at sub-terahertz frequencies as a communication channel
We study experimentally the transmission of an electromagnetic waveguide in the frequency range from 160 to 300 GHz. Photo-mixing is used to excite and detect the fundamental TE10 mode in a rectangular waveguide with two orders-of-magnitude lower impedance. The large impedance mismatch leads to a strong frequency dependence of the transmission, which we measure with a high-dynamic range of up to 80 dB and with high frequency-resolution. The modified transmission function is directly related to the information rate of the waveguide, which we estimate to be about 1 bit per photon. We suggest that the results are applicable to a Josephson junction employed as a single-photon source and coupled to a superconducting waveguide to achieve a simple on-demand narrow-bandwidth free-space number-state quantum channel
Efficiency of the Wilks and IPF Formulas at Comparing Maximal Strength Regardless of Bodyweight through Analysis of the Open Powerlifting Database
International Journal of Exercise Science 13(4): 567-582, 2020. The purpose of this study was to measure the efficiency of the Wilks and International Powerlifting Federation (IPF) Formulas at comparing powerlifting performance (total) between weight classes of the same sex (men and women) and division (classic and equipped) in order to determine the champion of champions. The Open Powerlifting database was downloaded (June 21st, 2019), filtered (Python) and analyzed (IBM SPSS). Single factor ANOVA revealed that the total (kg) was able to compare 3 out of the 98 weight class comparison possibilities (3.1%), the total ratio was able to compare 5 of the 98 weight class comparison possibilities (5.1%), the Wilks Formula was able to compare 53 of the 98 weight class comparison possibilities (54.1%) and that the IPF formula was able to compare 51 of the 98 weight class comparison possibilities (52%). Making the Wilks slightly more efficient than the IPF Formula (54.1% \u3e 52%) at determining the champion of champions. Results also show that the IPF Formula is more efficient at comparing women’s weight classes and that the Wilks Formula is more efficient at comparing men’s weight classes, for both divisions. Results could not validate the IPF’s decision to replace the Wilks by the IPF Formula. Subjects’ performances (kg, ratio, % of the event on the total, Wilks and IPF points) presented for each weight class per sex and division coming from a total of 26,472 open powerlifters could be utilized by practitioners. Further research should be directed towards updating the constants of both formulas
TreeToReads - a pipeline for simulating raw reads from phylogenies.
BackgroundUsing phylogenomic analysis tools for tracking pathogens has become standard practice in academia, public health agencies, and large industries. Using the same raw read genomic data as input, there are several different approaches being used to infer phylogenetic tree. These include many different SNP pipelines, wgMLST approaches, k-mer algorithms, whole genome alignment and others; each of these has advantages and disadvantages, some have been extensively validated, some are faster, some have higher resolution. A few of these analysis approaches are well-integrated into the regulatory process of US Federal agencies (e.g. the FDA's SNP pipeline for tracking foodborne pathogens). However, despite extensive validation on benchmark datasets and comparison with other pipelines, we lack methods for fully exploring the effects of multiple parameter values in each pipeline that can potentially have an effect on whether the correct phylogenetic tree is recovered.ResultsTo resolve this problem, we offer a program, TreeToReads, which can generate raw read data from mutated genomes simulated under a known phylogeny. This simulation pipeline allows direct comparisons of simulated and observed data in a controlled environment. At each step of these simulations, researchers can vary parameters of interest (e.g., input tree topology, amount of sequence divergence, rate of indels, read coverage, distance of reference genome, etc) to assess the effects of various parameter values on correctly calling SNPs and reconstructing an accurate tree.ConclusionsSuch critical assessments of the accuracy and robustness of analytical pipelines are essential to progress in both research and applied settings
Performance and Wake Analysis of a Darrieus Wind Turbine on the Roof of a Building using CFD
In order to reduce greenhouse gas emissions and counter climate change, efforts have been made towards the development of technologies in the field of renewable energies. Wind turbines emerged has a result of these efforts. A significant amount of research has been made to increase their power producing capabilities. The concept of positioning micro-scale wind turbines on the roof of buildings is currently being studied due to the possible benefits of onsite power generation. The research detailed in this thesis concentrates on the performance and wake analysis of a Darrieus wind turbine, with a Troposkien shape, located above the roof of a cubic building at two different positions and operating under different wind flow conditions. The results presented are obtained from 3D unsteady Computational Fluid Dynamics (CFD) simulations and the applied methodology is validated by comparing coefficient of power (Cp) data from validation cases with a Cp – λ curve acquired experimentally by Sheldahl. The first position considered is above the center upstream edge of the building, whereas the second one is located above one of the upstream building roof’s corners at a lower height. An atmospheric boundary layer is enforced at the inlet of the domain with a selected desired velocity pointing at the center of the rotor. Cp values from the roof-mounted simulations are computed using various tip speed ratios and three different wind directions. Furthermore, the rotor’s wakes in each scenario are measured and their behaviors are discussed. It is found that at a tip speed ratio of 5, the turbine’s Cp can be increased from 0.318 to 0.549 by positioning it above the building’s corner. Analysis of the rotor wake’s structure at this location also revealed that because the wake mixes with the surrounding accelerated flow, it is shorter than when operating in a freestream
Jeunes et syndicalisme : une intégration réussie? Analyse comparative de deux organisations syndicales du Québec
Cette recherche dresse un portrait de la situation de la relève syndicale au Québec et des tentatives des organisations syndicales pour stimuler la participation de leurs membres de moins de 30 ans. Elle brosse d’abord un aperçu des habitudes sociales, des valeurs et des caractéristiques en emploi des jeunes. Elle nuance et recadre ensuite la problématique des jeunes en ce qui concerne l’identité collective qu’ils partagent instinctivement et les modalités de socialisation à l’interne façonnant leur participation. Cette recherche remet en question la fenêtre de recrutement estimée où les jeunes seraient en mesure d’entâmer leur participation dans les structures syndicales. Au demeurant, elle décrit l’ampleur des innovations syndicales destinées à stimuler la participation des jeunes et démystifie le mandat de l’une d’elle, les comités jeunes, qui peuvent agir à la fois comme porte-parole de leur organisation, comme la voix des jeunes membres et comme pépinière de la relève syndicale.
Les données empiriques utilisées pour ce mémoire proviennent d’une vingtaine de groupes de discussion et de huit entretiens semi-dirigés (n=228), tenus dans deux organisations syndicales d’importance au Québec, disposant d’un comité jeunes et organisés par les chercheures d’un projet de recherche plus vaste sur la participation syndicale des jeunes.
Nos résultats démontrent en premier lieu une identité collective construite autour de la précarité et des injustices perçues par les nouveaux travailleurs. L’âge ne serait pas significatif dans la construction de l’identité des jeunes qui semblent en phase de conquérir leur identité. En second lieu, le cadre strict de plusieurs modalités de socialisation avait un effet inhibiteur sur la participation, favorisait des relations d’échanges instrumentales et ne tenait pas compte de la sensibilité de cette nouvelle génération pour les interactions réciproques avec leurs représentants syndicaux. Nous avons aussi observé une utilisation limitée des nouvelles technologies, qui présentent des potentialités intéressantes en matière de transfert des connaissances de surcroît. Par ailleurs, nos résultats à l’égard de l’identité collective observée et de la durée du processus de socialisation soulèvent des questionnements sur la pertinence même des structures jeunes dans leurs paramètres actuels. Le parcours d’un jeune vers la militance syndicale apparaît plus tardif qu’escompté. Plus encore, la problématique jeunes met en lumière les tensions intrinsèques au mouvement syndical quant à la libre négociation sociale des intérêts défendus et du consensus interne nécessaire à leur légitimité.This research addresses the situation of Québec’s trade unions’ youth and the trade unions’ attempts to stimulate the participation of those under 30 years old. It also helps to describe social habits, values and characteristics at work of young workers. Then it qualifies and reframes the youth issue in terms of their shared identity and the socialization mechanisms shaping their participation. This research brings into question the actual recruitment window when young members could start participating into their unions. Finally, it describes some trade unions’ strategies to stimulate youth’s participation and clarifies one of the, the youth committees, who not only have the mandate to act as the unions’ spokesperson, but also as the youth’s voice from the inside and as a school for the trade unions’ next generation of members.
The chosen qualitative methodology comes from twenty focus groups and eight semi-structured interviews (n=228) held in two notorious trade unions in Québec which had youth committees and organized by the researchers of a larger research project on youth’s participation.
Our results show a collective identity built around precariousness and perceived unfair treatments by the newest workers. We found that age was not a significant factor in building collective identity and young members were still battling to express their own collective identity. Besides, it shows how the rigid frame of many socialization mechanisms had inhibiting effects on participation, positionned members in an instrumental relationship with their trade union and did not take into account this generation’s sensitivity for reciprocal interactions with their union representatives. We also observed weak engagement coming from trade unions towards new technologies, which seemed a great opportunity for knowledge transfer regarding the new generations of workers. In addition, our results about the observed collective identity and the actual duration of the socialization process bring into question the relevance of youth structures within their actual parameters. The journey of a young member towards union activism seemed to take more time than estimated. Moreover, the youth issue highlights inherent tensions to the labour movement’s social negotiation of the defended interests and the consensus needed for their legitimacy
Efficient design of rectifying antennas for low power detection
ISSN : 0149-645X E-ISBN : 978-1-61284-756-6 Print ISBN: 978-1-61284-754-2 INSPEC Accession Number: 12240657International audienceThis article is dedicated to the design of rectifying antenna for wireless energy transfer at 2.45 GHz and low input power (−10 dBm). Specific design guidelines must be respected to optimize the structure. Different rectifying circuits have been studied and their performances have been evaluated. The effects of the antenna impedance have been investigated to improve the performances. Two test-circuits have been manufactured and measured to validate the interest of a global design approach
Characterization of microflora in Latin-style cheeses by next-generation sequencing technology
Background
Cheese contamination can occur at numerous stages in the manufacturing process including the use of improperly pasteurized or raw milk. Of concern is the potential contamination by Listeria monocytogenes and other pathogenic bacteria that find the high moisture levels and moderate pH of popular Latin-style cheeses like queso fresco a hospitable environment. In the investigation of a foodborne outbreak, samples typically undergo enrichment in broth for 24 hours followed by selective agar plating to isolate bacterial colonies for confirmatory testing. The broth enrichment step may also enable background microflora to proliferate, which can confound subsequent analysis if not inhibited by effective broth or agar additives. We used 16S rRNA gene sequencing to provide a preliminary survey of bacterial species associated with three brands of Latin-style cheeses after 24-hour broth enrichment. Results
Brand A showed a greater diversity than the other two cheese brands (Brands B and C) at nearly every taxonomic level except phylum. Brand B showed the least diversity and was dominated by a single bacterial taxon, Exiguobacterium, not previously reported in cheese. This genus was also found in Brand C, although Lactococcus was prominent, an expected finding since this bacteria belongs to the group of lactic acid bacteria (LAB) commonly found in fermented foods. Conclusions
The contrasting diversity observed in Latin-style cheese was surprising, demonstrating that despite similarity of cheese type, raw materials and cheese making conditions appear to play a critical role in the microflora composition of the final product. The high bacterial diversity associated with Brand A suggests it may have been prepared with raw materials of high bacterial diversity or influenced by the ecology of the processing environment. Additionally, the presence ofExiguobacterium in high proportions (96%) in Brand B and, to a lesser extent, Brand C (46%), may have been influenced by the enrichment process. This study is the first to define Latin-style cheese microflora using Next-Generation Sequencing. These valuable preliminary data will direct selective tailoring of agar formulations to improve culture-based detection of pathogens in Latin-style cheese
Ultrafast quantitative ultrasound and shear wave elastography imaging of in vivo duck fatty livers
Multi-parametric ultrasound imaging is a
promising tool for quantification of nonalcoholic fatty
liver disease. In this work, a protocol of plane wave
quantitative ultrasound (QUS) and shear wave
elastography imaging (SWEI), quasi-simultaneously
acquired, dedicated to quantification of liver steatosis
on in vivo fatty duck liver is presented. Shear wave
velocity was estimated to classify stiffness in duck liver
tissue. QUS consisted of local attenuation coefficient
slope estimated with Spectral Log Difference method,
and coherent-to-diffuse signal ratio computed from
homodyned-K parametric maps. After 9 days of feeding,
US attenuation reached a maximum and coherent-todiffuse signal ratio reached a minimum. Coupled
together, QUS and SWEI promise a strong potential in
steatosis monitoring of fatty liver tissue, in ducks or
humans
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