Breaking the Rayleigh-Plateau instability limit using thermocavitation within a droplet

We report on the generation of liquid columns that extend far beyond the traditional Rayleigh-Plateau instability onset. The columns are driven by the acoustic pressure wave emitted after bubble collapse. A high-speed video imaging device, which records images at a rate of up to 105 fps, was employed to follow their dynamics. These bubbles, commonly termed thermocavitation bubbles, are generated by focusing a midpower (275 mW) continuous wavelength laser into a highly absorbing liquid droplet. A simple model of the propagation of the pressure wavefront emitted after the bubble collapse shows that focusing the pressure wave at the liquid-air interface drives the evolution of the liquid columns. Control over the aspect ratio of the liquid column is realized by adjusting the cavitation bubble's size, beam focus position, and droplet volume. © 2013 by Begell House, Inc

Controllable direction of liquid jets generated by thermocavitation within a droplet.

A high-velocity fluid stream ejected from an orifice or nozzle is a common mechanism to produce liquid jets in inkjet printers or to produce sprays among other applications. In the present research, we show the generation of liquid jets of controllable direction produced within a sessile water droplet by thermocavitation. The jets are driven by an acoustic shock wave emitted by the collapse of a hemispherical vapor bubble at the liquid-solid/substrate interface. The generated shock wave is reflected at the liquid-air interface due to acoustic impedance mismatch generating multiple reflections inside the droplet. During each reflection, a force is exerted on the interface driving the jets. Depending on the position of the generation of the bubble within the droplet, the mechanical energy of the shock wave is focused on different regions at the liquid-air interface, ejecting cylindrical liquid jets at different angles. The ejected jet angle dependence is explained by a simple ray tracing model of the propagation of the acoustic shock wave inside the droplet

A European perspective on nosocomial urinary tract infections II. Report on incidence, clinical characteristics and outcome (ESGINI–04 study)

ObjectivesTo estimate the incidence of nosocomially acquired urinary tract infections (NAUTI) in Europe and provide information on the clinical characteristics, underlying conditions, etiology, management and outcome of patients.Materials and methodsWe collected clinical information from NAUTI patients with a microbiology report on the named study day.ResultsA total of 141 hospitals from 25 European countries participated in the study. Written institutional bladder catheter guidelines were in place in 90.3% of EU hospitals and 55% of non-EU hospitals (P <0.05). The total number of new NAUTI episodes on the day of the study was 298, representing an incidence of 3.55 episodes/1000 patient-days and an estimated prevalence of 10.65/1000. The five most commonly isolated micro-organisms were Escherichia coli, Enterococcus sp., Candida sp., Klebsiella sp. and Pseudomonas aeruginosa. Patients from non-EU countries were younger, with more severe underlying diseases with a higher incidence of obstructive uropathy/lithiasis. Overall, 22.8% of patients had no ‘classic’ UTI-predisposing factors. Catheter-associated UTI (CAUTI) was present in 187 patients (62.8%). A closed drainage system was used in only 78.5% of catheterised patients. The indication for bladder catheterisation was not considered adequate in 7.6% of cases and continuation of bladder catheterisation was considered unnecessary in 31.3%. Opening of the closed drainage system was the most frequent major error in catheter management (16.8%). Antimicrobial treatment was not considered adequate in 19.8% of all cases.ConclusionsThe incidence of NAUTI in a large European population is 3.55/1000 patient-days. There is clearly room for improvement in the area of bladder catheterisation, catheter care and medical management of NAUTI. We recommend that European authorities draw up and implement practical and specific guidelines to reduce the incidence of this infection

Mindfulness and other simple neuroscience-based proposals to promote the learning performance and mental health of students during the COVID-19 pandemic

The COVID-19 pandemic has had a negative impact on education. The restrictions imposed have undoubtedly led to impairment of the psychological well-being of both teachers and students, and of the way they experience interpersonal relationships. As reported previously in the literature, adverse effects such as loneliness, anxiety, and stress have resulted in a decrease in the cognitive performance of school and higher education students. Therefore, the objective of this work is to present a general overview of the reported adverse effects of the COVID-19 pandemic which may potentially influence the learning performance of students. Some neuroscientific findings related to memory and cognition, such as neuroplasticity and long-term potentiation, are also shown. We also discuss the positive effects of the practice of mindfulness, as well as other simple recommendations based on neuroscientific findings such as restful sleep, physical activity, and nutrition, which can act on memory and cognition. Finally, we propose some practical recommendations on how to achieve The COVID-19 pandemic has had a negative impact on education. The restrictions imposed have undoubtedly led to impairment of the psychological well-being of both teachers and students, and of the way they experience interpersonal relationships. As reported previously in the literature, adverse effects such as loneliness, anxiety, and stress have resulted in a decrease in the cognitive performance of school and higher education students. Therefore, the objective of this work is to present a general overview of the reported adverse effects of the COVID-19 pandemic which may potentially influence the learning performance of students. Some neuroscientific findings related to memory and cognition, such as neuroplasticity and long-term potentiation, are also shown. We also discuss the positive effects of the practice of mindfulness, as well as other simple recommendations based on neuroscientific findings such as restful sleep, physical activity, and nutrition, which can act on memory and cognition. Finally, we propose some practical recommendations on how to achieve more effective student learning in the context of the pandemic. The aim of this review is to provide some assistance in this changing and uncertain situation in which we all find ourselves, and we hope that some of the information could serve as a starting point for hypotheses to be tested in educational research and their association with neuroscience.This research was funded by the Dirección de Investigación-Universidad de La Frontera (DI20-1003) and Project Covid (73) Process number: 23006.002357/2020-20—Universidade Federal do ABC. In addition, this work was partially funded by FEDER funds through the Operational Competitiveness Program—COMPETE and by National Funds through Fundação para a Ciência e Tecnologia (FCT)—under the projects PTDC/CTM-TEX/28295/2017 and UID/CTM/00264/2019

Setting conclitions, Petrology ancl Geochemistry of calc-alkaline rhyolites, stephanian-permian, in the iberian chains

[Resumen] Se exponen los caracteres del emplazamiento, la composición petrológica y geoquímica de unos sills riolíticos que, con afinidad calco-alcalina, se emplazaron, bajo un ambiente sin-colisional, en diversos sectores de la Cadena Ibérica. Estas riolitas representan un origen crustal, con baja tasa de fusión, previo a un magmatismo calco-alcalino de origen subcrustal.[Abstract] The setting characters, the petrological and geochemical composition are exposed for sorne rhyolitic sills, with calc-alkaline affinity, which were set, in a syncollisional environment, in several areas of the Iberian Chains. These rhyolites represent a crustal origin, with a low degree of fussion, previous to a calc-alkaline magmatism of subcrustal origino

Design of Science Orbits About Planetary Satellites: Application to Europa

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76381/1/AIAA-19464-587.pd

An Experience in Integrated Knowledge about Manufacturing Technologies for Students of the Grades of Industrial Engineering

AbstractIn the development of the specific skills in the field of industrial engineering, the transversality of the contents of each area of knowledge must be considered. This paper shows how the integration of the contents of different areas (such as materials, manufacturing, design, etc.) is performed in order to allow students to enhance their transversal skills. For this, a specific product is proposed as “learning object”. The analysis, to be made by the students, includes all the aspects regarding technical and economic feasibility, and manufacturing optimization of the product. The article also shows the analysis of the work environment and the established methodology by an interdisciplinary group of university teachers from different areas: materials, manufacturing and design who have contributed with their knowledge in the specific problem

Serendipitous discovery of RR Lyrae stars in the Leo V ultra-faint galaxy

During the analysis of RR Lyrae stars discovered in the High cadence Transient Survey (HiTS) taken with the Dark Energy Camera at the 4-m telescope at Cerro Tololo Inter-American Observatory, we found a group of three very distant, fundamental mode pulsator RR Lyrae (type ab). The location of these stars agrees with them belonging to the Leo V ultra-faint satellite galaxy, for which no variable stars have been reported to date. The heliocentric distance derived for Leo V based on these stars is 173 +/- 5 kpc. The pulsational properties (amplitudes and periods) of these stars locate them within the locus of the Oosterhoff II group, similar to most other ultra-faint galaxies with known RR Lyrae stars. This serendipitous discovery shows that distant RR Lyrae stars may be used to search for unknown faint stellar systems in the outskirts of the Milky Way.Comment: Accepted in ApJ Letter

Novel effects of strains in graphene and other two dimensional materials

The analysis of the electronic properties of strained or lattice deformed graphene combines ideas from classical condensed matter physics, soft matter, and geometrical aspects of quantum field theory (QFT) in curved spaces. Recent theoretical and experimental work shows the influence of strains in many properties of graphene not considered before, such as electronic transport, spin-orbit coupling, the formation of Moir\'e patterns, optics, ... There is also significant evidence of anharmonic effects, which can modify the structural properties of graphene. These phenomena are not restricted to graphene, and they are being intensively studied in other two dimensional materials, such as the metallic dichalcogenides. We review here recent developments related to the role of strains in the structural and electronic properties of graphene and other two dimensional compounds.Comment: 75 pages, 15 figures, review articl

Impact of the COVID-19 pandemic on older adults mental health services: A mixed methods study

Objectives: The COVID-19 pandemic has had a significant impact on older adults mental health care. Our study aimed to explore staff perspectives on key challenges and innovations in order to help inform the delivery of older adults mental health care in subsequent waves of the pandemic. // Methods: A mixed methods online questionnaire developed by National Institute for Health Research Mental Health Policy Research Unit was used to gather staff perspectives on their challenges at work, problems faced by service users and their carers, and sources of help and support. Descriptive statistics were used for quantitative analysis and descriptive content analysis for qualitative analysis. // Results: 158 participants, working in either community or inpatient settings, and from a range of professional disciplines, were included. For inpatient staff, a significant challenge was infection control. In the community, staff identified a lack of access to physical and social care as well as reduced contact with friends and families as being challenges for patients. Remote working was seen as a positive innovation along with COVID-19 related guidance from various sources and peer support. // Conclusion: Our study, with a focus on staff and patient well-being, helps to inform service development for future waves of the pandemic. We discuss measures to improve infection control in inpatient settings, the role of voluntary organisations in supporting socially isolated community patients, the need for better integration of physical and mental health services at an organisational level, and the importance of training staff to support patients and their families with end of life planning