Detection of Spiral photons in Quantum Optics

We show that a new type of photon detector, sensitive to the gradients of electromagnetic fields, should be a useful tool to characterize the quantum properties of spatially-dependent optical fields. As a simple detector of such a kind, we propose using magnetic dipole or electric quadrupole transitions in atoms or molecules and apply it to the detection of spiral photons in Laguerre-Gauss (LG) beams. We show that LG beams are not true hollow beams, due to the presence of magnetic fields and gradients of electric fields on beam axis. This approach paves the way to an analysis at the quantum level of the spatial structure and angular momentum properties of singular light beams.Comment: 5 pages, 4 figure

An improved electronic circuit for tracing the I-V characteristics of photovoltaic modules and strings

This paper presents an improved electronic circuit for testing photovoltaic (PV) modules or strings by tracing their I-V and P-V characteristics. It consists of an electronic fast varying load based on a power MOSFET controlled by means of an innovative sweeping gate-source voltage in order to improve the tracing of the I-V characteristics on an oscilloscope. In order to prevent damage of data acquisition systems and mainly for use with high voltage PV strings, galvanic isolation is introduced for the sweeping signal as well as current and voltage measurements. In spite of this improved characteristics, the developed electronic circuit keeps the advantages of low cost and simplicity. Experimental results obtained with the electronic circuit are presented

Numerical solution of linear models in economics: The SP-DG model revisited

In general, complex and large dimensional models are needed to solve real economic problems. Due to these characteristics, there is either no analytical solution for them or they are not attainable. As a result, solutions can be only obtained through numerical methods. Thus, the growing importance of computers in Economics is not surprising. This paper focuses on an implementation of the SP-DG model, using Matlab,developed by the students as part of the Computational Economics course. We also discuss some of our teaching/learning experience within the course, given for the first time in the FEP Doctoral Programme in Economics.SP-DG Model, Output, Inflation, Numerical Simulation, Teaching of Economics

Supporting childbirth knowledge acquisition and decision-making through digital communication technology: the research design of an ongoing study following a mixed-method approach

This paper describes the research design of an ongoing study that overlaps three main fields: technology, health, and social science. This transdisciplinarity approach naturally brings challenges to the methodological plan, which this paper presents, and aims to guide the creation, validation and evaluation of a digital decision aid, and its comparison to a paper-based solution. Through the data collection from different natures, it is expected to be possible to understand the different sources, channels and formats of content that can contribute for childbirth knowledge acquisition; if communication can be facilitated between expectant parents, health care professionals, and childbirth educators; and ultimately, if the tool could provide a mean to create a document regarding birth preferences.publishe

An exploration of barriers to implement Lean in the emergency level of the Brazilian public healthcare system

The overarching aim of this thesis is to understand the barriers to implement lean in the emergency level of the Brazilian public healthcare system (UHS). As one of the BRICS countries, Brazil as a developing country has challenges in terms of education, infrastructure and healthcare. Thus, this research aims to bring lean into this context and investigate the constraints of a future lean implementation in the UHS. The UHS presents several operational and non-operational problems. These problems constrain the system and affect the patients. Lean is a well-known approach that has been applied around the world with special focus in developed countries. However, these initiatives have also experienced several barriers that act to inhibit the lean journey. Scholars and practitioners have investigated these barriers, however approaches that show the deeper causes, especially in healthcare, are still scarce. Thus, this brought an opportunity to carry out original research about the barriers that constrain the lean implementation in a different context. To achieve the aim of this thesis, a qualitative and inductive approach based on a single case study in the emergency level of the UHS was undertaken. This approach is supported with the interpretivist philosophical stance adopted by the researcher. To access the data, interviews and observations were carried out; these approaches were used in different ways in four different sources of data collection: one emergency care unit (ECU); one emergency department (ED); lean management consultants; and staff members from a lean private hospital. The data from these sources was triangulated and analysed using thematic analysis. The results show that there are two types of barriers that might constrain the lean implementation in the UHS. The first type of barrier is entitled ostensible, as they are well known within the literature. The other type of barrier is entitled underlying and they have a great influence of the stakeholders behaviour and UHS management style, which act as restraining forces against process improvement. Furthermore, these underlying barriers were identified as the real causes of the ostensible barriers. This research provides both theoretical and practical contributions. The theoretical contribution brings a new body of knowledge based on findings related to identification of the underlying barriers that constraint the lean implementation in the UHS; the contextual contribution was also addressed in this study as there is no research about lean barriers in this setting; finally the field of forces in healthcare (based on force field analysis (Lewin, 1951) was developed to understand the interplay between underlying barriers, restraining forces from stakeholders and UHS, and the creation of the ostensible barriers. The practical contribution provides support for lean practitioners and management consultants about the impact of the Brazilian public administration model in the lean journey, as well as the impact of the underlying barriers in the lean journey. Finally, a set of propositions was developed based on outcomes that emerged during the development of this research

Experimental evaluation of new one-chip solution for induction motor drives

The design of high performance induction motor drives is a complex task, and the every day compelling requirements in energy efficiency and performance assumes the motivation on finding a more integrated solution on implementing induction motor control. The main subjects of this paper are two: to discuss the IFOC one-chip solution and to explore the development of simple graphical applications in order to operate this control in a simple and effective way. Experimental results are presented to illustrate the main points of our paper