920 research outputs found
Weak value amplification: a view from quantum estimation theory that highlights what it is and what isn't
Weak value amplification (WVA) is a concept that has been extensively used in
a myriad of applications with the aim of rendering measurable tiny changes of a
variable of interest. In spite of this, there is still an on-going debate about
its true nature and whether is really needed for achieving high sensitivity.
Here we aim at solving the puzzle, using some basic concepts from quantum
estimation theory, highlighting what the use of the WVA concept can offer and
what it can not. While WVA cannot be used to go beyond some fundamental
sensitivity limits that arise from considering the full nature of the quantum
states, WVA can notwithstanding enhance the sensitivity of real detection
schemes that are limited by many other things apart from the quantum nature of
the states involved, i.e. technical noise. Importantly, it can do that in a
straightforward and easily accessible manner.Comment: 2 pages, 5 figure
Low-pay higher pay and job satisfaction within the European Union: empirical evidence from fourteen countries
We examine differences in job satisfaction between low- and higher-paid workers within the European Union (EU). To do so The European Community Household Panel Data covering the period 1994-2001 is used. Then we test for differences in reported job satisfaction between low- and higher-paid workers. We also explain the existence of differences in the determinants of job satisfaction between these two types of workers and across countries. Our results indicate that low paid workers report a lower level of job satisfaction when compared with their higher paid counterparts in most countries, except in the UK. This supports the idea that low-wage employment in these countries mainly comprises low quality. The results also indicate that gap in average job satisfaction between low- and higher-paid workers is markedly wider in the Southern European countries than in the rest of EU. Finally, there are significant differences in the determinants of job satisfaction across countries. It seems then that a homogeneous policy may be inappropriate to increase satisfaction, and hence labour productivity, in the EU as a whole. Hence, an improvement of the quality of the jobs in the EU may require different policies. In particular, in some countries such as the United Kingdom removing low employment, namely through regulation, may worsen the workersâ well-being, although in other cases such a policy may lead to a totally different outcome.Job satisfaction,job quality,low-wage employment
Low-pay higher pay and job satisfaction within the European Union empirical evidence from fourteen countries.
We examine differences in job satisfaction between low-and higher-paid workers within the European Union (EU). to do so The European Community Houlshold Panel Data covering the period 1994-2001 is used. Then we test for differences in reported job satisfaction between these two types of workers and across countries. Our results inducate that low paid workers report a lower level of job satisfaction when compared with their higher paid counterparts in most countries, except in the UK. This supports the idea that low-wage employment in these countries mainly comprises low quality. The results also indicate that gap in average job satisfaction between low-and higher-paid workers is markedly wider in the Southern European countries than in the rest of EU. Finally, there are significant differences in the determinants of job satisfaction across countries. It seems then that a homeogeneous policy may be inapporopriate to increase satisfaction, and hence labour productivity, in the EU as a whole. Hence, lan imporovement of the quality of the jobs in the EU may require different policies. In particular, in some countries such as the United Kingdome removing low employment, namely through regulation, may worsen the workers' well-being. although in other cases such a policy may lead to a totally different outcome
COVID-19 Infection among Nursing Students in Spain: The Risk Perception, Perceived Risk Factors, Coping Style, Preventive Knowledge of the Disease and Sense of Coherence as Psychological Predictor Variables: A Cross Sectional Survey
The exploration of patterns of health beliefs about COVID-19 among nursing students may be beneficial to identify behaviors, attitudes and knowledge about contagion risk. We sought to analyze the variables of risk perception, perceived risk factors, coping style, sense of coherence and knowledge of preventive measures as possible predictors of having suffered from COVID-19. Participants were nursing students from 13 universities in Spain. Sociodemographic and health variables were collected. To test the independent variables, the Perception Risk Coping Knowledge (PRCK-COVID-19) scale was created and validated because there was no specific survey for young people adapted to the pandemic situation of COVID-19. It was validated with adequate psychometric properties. A total of 1562 students (87.5% female, mean age 21.5 +/- 5.7 years) responded. The high perception of the risk of contagion, the high level of knowledge and a coping style focused on the situation were notable. Significant differences by gender were found in the coping styles, problem-focused, avoidance and knowledge scales, with women scoring higher in all categories. The multiple regression analysis was significant (F = 3.68; p < 0.001). The predictor variables were the coping styles subscale search for support and the intrinsic and extrinsic perceived risk factors. Our model predicts that nursing students with a social support-based coping style are at a higher risk of becoming infected with COVID-19, based on their own health belief model
IniciaciĂłn deportiva en EducaciĂłn Primaria
Los cambios producidos en las metodologĂas de enseñanza-aprendizaje en EducaciĂłn fĂsica han traĂdo que el alumno tome mayor protagonismo en su aprendizaje.
El dar al alumno el conocimiento y oportunidad de conocer mĂĄs opciones de prĂĄctica de ejercicio fĂsico ayudarĂĄ a la autonomĂa y empoderamiento de Ă©ste a la hora de elegir su prĂĄctica de actividad fĂsica. Para ello se debe conocer los tipos de deportes que se pueden practicar (individuales, de equipo, oposiciĂłn, etc.) y cĂłmo se puede iniciar al alumnado en estos deportes, siempre teniendo en cuenta los valores Ă©ticos. Es parte importante usar diferentes tipos de modelos de enseñanza para asĂ ir implicando al alumno en una mayor independencia en su aprendizaje. En este trabajo se muestra una propuesta de intervenciĂłn, concretamente una unidad didĂĄctica sobre la iniciaciĂłn deportiva en un deporte en particular: hockey, con el objetivo de que el alumno conozca y aprenda sobre dicho deporte, y sobre todo adquiera conocimientos para la iniciaciĂłn deportiva y pueda reflejarlos en cualquier deporte que quiera practicar fuera del horario escolar.Grado en EducaciĂłn Primari
Mejora de la competitividad del sistema portuario español mediante la optimizaciĂłn del servicio de manipulaciĂłn de mercancĂas
Los servicios portuarios son responsables de la mayor parte del coste que se produce en el paso de la mercancĂa por un puerto, particularmente el servicio de manipulaciĂłn de mercancĂas. La prestaciĂłn de Ă©stos de forma fiable y eficiente resulta clave en un sector en el que existe una gran opacidad. Con el estudio realizado se dota a la AdministraciĂłn responsable, la Autoridad Portuaria, de una herramienta que le ayude a objetivar la toma de decisiones tanto a la hora de otorgar las preceptivas licencias como durante el periodo de prestaciĂłn del servicio. AdemĂĄs se proponen una serie de medidas cuya aplicaciĂłn mejorarĂa las condiciones de prestaciĂłn del servicio asĂ como una reducciĂłn de costes al paso de la mercancĂa por el puerto.
Port services are responsible for most of the cost for the passing of goods through the port, especially the cargo handling service. Reliability and efficiency in the provision of them are key in a sector where there is a high opacity. With this study, we provide the responsible Administration, the Port Authority, with a tool that will help to objectify the decision making process, both at the time of granting the required licenses and during the period of the service provision. Also, proposes a number of measures whose implementation would improve the conditions of the service delivery and will reduce the total cost of transporting goods through the port
Modeling the external flow of a novel HorseShoe receiver and the evaluation of thermal performance
The linear receiver of a Parabolic Trough Collector is the most critical element in the entire system. The Universal Vacuum Air Collector concept is the most extended type of receiver in both experimental and industrial facilities. Besides their considerable cost, their efficiency usually drops as operation time passes. This is mainly due to a partial loss of vacuum in the evacuated annulus between the absorber and the glass cover. An alternative design called HorseShoe receiver is proposed in this work, whose main goal is to maintain the thermal performance throughout its entire lifespan. This innovative receiver is indicated for low-to-medium temperature ranges, which is particularly suitable for solar heat for industrial processes. It consists of a horseshoe-like cavity absorber having its upper border insulated. In addition, two main advantages can be taken by using two symmetric lenses as glass cover: reconcentrate solar radiation into the cavity (improvement of the intercept factor) and protect stratification conditions (reduction of thermal losses). A transient numerical model with customized boundary conditions has been implemented to evaluate both thermal performance and temperature difference in the absorber domain, which is critical for the thermal stress conditions. For that purpose and as a key contribution, not only the Heat Transfer Fluid (HTF) temperature but also the heat transfer coefficient in the duct are set. In particular, HTF temperature ranges from 80 °C to 220 °C and the inner heat transfer coefficient from 600 W/(mK) to 1800 W/(mK). Results show that numerical thermal performance is above 96%, which is mainly due to the reduction of thermal radiation losses, where the absorber active surface emittance is . (...)Second (corresponding) author J.J. Serrano-Aguilera acknowledges the support provided by Junta de AndalucĂa (Government of Andalusia) and Universidad de MĂĄlaga for the source of funding for the HERTERSOL project (UMA18-FEDERJA-195), as well as to Ministerio de Ciencia, InnovaciĂłn Universidades (Spain) by means of the postdoc position: Ref No. FJCI-2017-32403 (Juan de la Cierva-FormaciĂłn Postdoc Grant). Third author acknowledges the support of Universidad de MĂĄlaga, Spain through the Project WALICON, 2021. Authors also acknowledge funding for open access charge: Universidad de MĂĄlaga / CBUA
Parabolic trough collectors. Fundamentals of heat transfer applied to solar thermal energy.
Solar thermal energy has undergone major development in recent years. The most
widely used technologies are central receiver solar towers and parabolic trough collectors (PTC)[1]. The latter technology has great advantages due to its higher optical
and thermal efficiency, but, despite being a well-proven technique, it presents certain
problems inherent to the manufacturing and durability of some critical elements in
the system. They are generally composed of an absorber tube surrounded by a glass
cover and in the intermediate space, a vacuum is created to minimize thermal losses
by convection[2]. The absorber tube is located at the focal line of a parabolic mirror
that concentrates sunâs rays. To predict the thermal behavior of this type of system,
ray-tracing techniques are used to determine the thermal load and accurate correlations are also needed to calculate the convective heat transfer. Also, the original design
shows some problems such as the selective coating applied on the absorber surface,
whose thermal performance decays with time. Besides, the metal-glass welding are
also a significant weak spot, which due to the thermal expansion can cause the partial
or total loss of the vacuum in the aforementioned annulus. In this work we present the
results of the modeling of this type of systems in different working configurations, as
well as a new design proposal to improve the thermal transfer in this type of systems.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Global stability map of the flow in a horizontal concentric cylinder forced by natural convection.
There are a large number of studies in the literature on natural convection in the annulus between horizontal concentric cylinders. However, not many publications dealing with global stability analysis in this kind of flow have been published. For a fixed diameter ratio L/Di = (Ro â Ri)/2Ri, being Ri and Ro the inner and outer cylinder radii respectively, and assuming Boussinesq approximation, the solution only depends on Prandtl (P r âĄ Îœ/α) and Rayleigh (Ra ⥠g ÎČ L3 (Ti â To)/(Îœ α)) numbers.
A spectral collocation code has been developed to solve the problem by means of Chebyshev and Fourier differentiation matrices for L/Di = 0.8 and it has been validated with classical experimental results. Steady solutions have been sought within the range P r â [1eâ2, 1] and Ra â [1e-2, 5e6]. As a result, a steady solution Pr-Ra map (consisting of 149 x 75 points) has been traced, where the different families of similar solutions found are detailed, mainly characterized by presenting single or
multiple plumes. In addition, two main double-solution regions have been found
The Role of e-Tutor Competencies in Postgraduate e-Learning Courses: Spotlight on Emotion Management
[EN] The role of e-learning in the existing and challenging educational era is crucial. However, it is necessary to overcome some drawbacks such as feelings of isolation and a lack of emotional contact. In this sense, emotion management is a key driver of student satisfaction in e-learning, which is significantly related to students' motivation, learning, cognitive strategies, self-regulation, and personality antecedents in the classroom. This article examines an online postgraduate course in financial statements auditing, describing the resources used by the e-tutor to conduct affective tutorials, reduce students' feelings of isolation, increase student involvement, and achieve success in e-learning. The results of a survey administered to 125 students over the period 2015 to 2020 indicate that students who receive emotional support have higher levels of satisfaction with the course in terms of all satisfaction indicators. In addition, female e-learning students are more satisfied with intensive e-tutor monitoring overall but are less gratified by non-face-to-face e-tools. Our study responds to the calls in the 2021-2027 Digital Education Action Plan to improve and reset education and training for the digital ageBustos-Contell, E.; Porcuna-Enguix, L.; Serrano-Madrid, J.; Labatut-Serer, G. (2021). The Role of e-Tutor Competencies in Postgraduate e-Learning Courses: Spotlight on Emotion Management. Sustainability. 13(17):1-13. https://doi.org/10.3390/su13179716S113131
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