509 research outputs found
Experimental evaluation of ultrasonic oscillating temperature sensors (UOTS) under cyclically changing temperatures
In contrast to most conventional temperature sensors, which need to come to thermal equilibrium with the medium of interest to report its temperature, UOTS interrogate
the medium based on the propagation speed of ultrasound, and
will return temperature data that are “averaged” for the
complete ultrasound pathway. It has been demonstrated that
UOTS can provide consistent high-resolution temperature
readings under steadily decreasing temperatures using
inexpensive ultrasonic transducers and low cost electronic
instrumentation
Experimental setup of continuous ultrasonic monitoring for corrosion assessment
The paper is devoted to the ultrasonic monitoring of accelerated corrosion. In order to achieve non-uniform corrosion (high surface roughness), passivation was applied to the corroding surface. A dedicated electronic multiplexed four channel front end was developed in order to feed the amplified waveforms from several transducers to the recording instrument. The experiment was conducted using two 5 MHz and two 10 MHz ultrasonic transducers all operating in the pulse echo mode. The transducers were excited in turn using gated bursts, and the received echoes were multiplexed and amplified before being digitized by a high accuracy ultrasonic instrument. Application of adaptive cross correlation to the recorded data allowed continuous thickness estimation of the non-uniformly corroded surface whilst cross correlation method gave unsatisfactory results
Embedded supervisory control and output reporting for the oscillating ultrasonic temperature sensors
Ultrasonic temperature sensors can potentially outperform conven-tional sensors because they are capable of very fast sensing across the complete ultrasound pathway, whilst conventional sensors only sense temperature at a single point and have substantial thermal inertia. We report recent develop-ments in electronic instrumentation for oscillating ultrasonic temperature sen-sors with the aim of achieving high accuracy and low scatter at a low cost
Accurate heat loss evaluation of water-cooled electric motors using a differential ultrasonic calorimeter
Measuring thermal losses of electric motors are important for their design optimization and correct pricing after manufacture. This measurement can be conducted by measuring the temperature difference of the motor coolant (commonly water) between the coolant's inlet and outlet. High speed of measurement facilitates testing various load scenarios and manufacture throughput; high measurement accuracy and resolution enables correct conclusions on efficiency of various design alterations and price bracketing of manufactured pieces.
Ultrasonic temperature sensors can fast sense temperature with high resolution and accuracy across the complete ultrasonic pathway. Conventional high resolution ultrasonic sensors are expensive; however, oscillating ultrasonic temperature sensors can be implemented using mass produced transducers and electronic parts which cost a fraction of the price of conventional high resolution ultrasonic measurement equipment.
The presented ongoing research focuses on development of a differential ultrasonic oscillating temperature sensor for evaluation of power losses in electrical motors. Computer simulations, electronic and firmware design, and experimental results are presented and discussed
Cross-cultural perspectives of LGBTQ psychology from five different countries: current state and recommendations
Lesbian, gay, bisexual, transgender and queer or questioning psychology (LGBTQ psychology) is a branch of psychology that promotes inclusiveness in theory and practice across the science of psychology, affirming the lives of people with different sexual orientations and forms of gender expression in a non-heterosexist and non-genderist perspective. This article highlights the historical development of LGBTQ psychology in the context of different realities for LGBTQ people in five different countries (Russia, Greece, Colombia, South Africa and the province of Quebec, Canada). Key experts on LGBTQ concerns report distinctive challenges they have faced when promoting LGBTQ rights and developing LGBTQ psychology (e.g., the pathologization and criminalization of sexual diversity, neglect on the part of authorities, and rejection from religious groups). Human and mental health sciences have played an important role in the blossoming of LGBTQ psychology. Cross-cultural narratives show that the recognition of lesbian and gay rights comes before the recognition of the rights of bi, trans, queer and questioning people. Various forms of homonegativity and transphobia still coexist even in countries that have established protections and rights recognition for LGBTQ people. We provide 15 strategies to help psychological organizations and psychologists around the world promote the development of LGBTQ psychology
Physical and mathematical modelling of pitting corrosion
The study of corrosion (especially pitting corrosion) is complicated by the highly random nature and slow rates of the natural corrosion process. We present an experimental setup for enabling accelerated corrosion, procedures for its use to accelerate physical modelling of pitting corrosion, and results of associated mathematical modelling
Additional Shear Wall Values for Light Weight Steel Framing (draft)
AlSI sponsored research at Santa Clara University (Serrette, 1996) led to the development of shear values for plywood, oriented strand board (OSB), and gypswn wallboard (GWB) sheathed light weight steel framed wall assemblies. The scope of the 1996 work was, however, limited to plywood, OSB. and GWB on 0.033 in. (20 gauge) framing. To provide a wider range of design options and clarify some of the values from the 1996 test program. a new test program was initialed. The new program included the following wall assemblies: flat strap X-braced walls. steel sheathed walls, high aspect ratio walls, and walls framed with 0.054 in. and 0.043 in. (16 gauge and 18 gauge, respectively} studs. As in the I 996 test program, the new assemblies were tested under static and cyclic loading. For each wall assembly configuration tested in the current program, the applied load, lateral displacement (at the top plate), slip, uplift, and mode of failure were monitored and recorded. Based on the test results, maximum loads (and corresponding displacements) were interpreted for design
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Effect of medical school attended on the chances of successfully embarking on a clinical-academic career in the UK.
PURPOSE OF THE STUDY: This study aimed to investigate whether, in the UK, medical school attended influences the propensity to apply to and be successful in obtaining an offer from the Academic Foundation Programme (AFP), thus taking the first step to embarking on a clinical-academic career. STUDY DESIGN: A retrospective observational study was performed. Using the UK Foundation Programme's yearly statistical report data, mean application rates to, and mean offer rates from the AFP were calculated by medical school, between the years 2017-2019. Mean application and mean offer rates were subsequently correlated with metrics of medical school academic performance and research focus. RESULTS: Mean application rates to the AFP were higher in medical schools that had a mandatory intercalated degree as part of the undergraduate medical curriculum (mean=33.99%, SD=13.93 vs mean=19.44%, SD=6.88, p<0.001), lower numerical rank in the Times Higher Education 2019 World Rankings (correlation with higher numerical rank, r=-0.50, p=0.004), and lower numerical rank in the Research Excellence Framework 2014 UK rankings (correlation with higher numerical rank, r=-0.37, p=0.004). Mean offer rates from the AFP were not correlated with any metric of medical school academic performance or research focus. CONCLUSIONS: Students attending a medical school with greater academic performance and research focus are more likely to apply and subsequently embark on a clinical-academic career. However, students wishing to embark a clinical-academic career from any medical school have an equal chance of success
Virtual classroom proficiency-based progression for robotic surgery training (VROBOT): a randomised, prospective, cross-over, effectiveness study
Robotic surgery training has lacked evidence-based standardisation. We aimed to determine the effectiveness of adjunctive interactive virtual classroom training (VCT) in concordance with the self-directed Fundamentals of Robotic Surgery (FRS) curriculum. The virtual classroom is comprised of a studio with multiple audio-visual inputs to which participants can connect remotely via the BARCO weConnect platform. Eleven novice surgical trainees were randomly allocated to two training groups (A and B). In week 1, both groups completed a robotic skills induction. In week 2, Group A received training with the FRS curriculum and adjunctive VCT; Group B only received access to the FRS curriculum. In week 3, the groups received the alternate intervention. The primary outcome was measured using the validated robotic-objective structured assessment of technical skills (R-OSAT) at the end of week 2 (time-point 1) and 3 (time-point 2). All participants completed the training curriculum and were included in the final analyses. At time-point 1, Group A achieved a statistically significant greater mean proficiency score compared to Group B (44.80 vs 35.33 points, p = 0.006). At time-point 2, there was no significant difference in mean proficiency score in Group A from time-point 1. In contrast, Group B, who received further adjunctive VCT showed significant improvement in mean proficiency by 9.67 points from time-point 1 (95% CI 5.18-14.15, p = 0.003). VCT is an effective, accessible training adjunct to self-directed robotic skills training. With the steep learning curve in robotic surgery training, VCT offers interactive, expert-led learning and can increase training effectiveness and accessibility
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A flavin-based extracellular electron transfer mechanism in diverse Gram-positive bacteria.
Extracellular electron transfer (EET) describes microbial bioelectrochemical processes in which electrons are transferred from the cytosol to the exterior of the cell1. Mineral-respiring bacteria use elaborate haem-based electron transfer mechanisms2-4 but the existence and mechanistic basis of other EETs remain largely unknown. Here we show that the food-borne pathogen Listeria monocytogenes uses a distinctive flavin-based EET mechanism to deliver electrons to iron or an electrode. By performing a forward genetic screen to identify L. monocytogenes mutants with diminished extracellular ferric iron reductase activity, we identified an eight-gene locus that is responsible for EET. This locus encodes a specialized NADH dehydrogenase that segregates EET from aerobic respiration by channelling electrons to a discrete membrane-localized quinone pool. Other proteins facilitate the assembly of an abundant extracellular flavoprotein that, in conjunction with free-molecule flavin shuttles, mediates electron transfer to extracellular acceptors. This system thus establishes a simple electron conduit that is compatible with the single-membrane structure of the Gram-positive cell. Activation of EET supports growth on non-fermentable carbon sources, and an EET mutant exhibited a competitive defect within the mouse gastrointestinal tract. Orthologues of the genes responsible for EET are present in hundreds of species across the Firmicutes phylum, including multiple pathogens and commensal members of the intestinal microbiota, and correlate with EET activity in assayed strains. These findings suggest a greater prevalence of EET-based growth capabilities and establish a previously underappreciated relevance for electrogenic bacteria across diverse environments, including host-associated microbial communities and infectious disease
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