Piezoelectricity and ferroelectricity in amino acid glycine

Bioorganic ferroelectrics and piezoelectrics are becoming increasingly important in view of their intrinsic compatibility with biological environment and biofunctionality combined with strong piezoelectric effect and switchable polarization at room temperature. Here we study piezoelectricity and ferroelectricity in the smallest amino acid glycine, representing a broad class of non-centrosymmetric amino acids. Glycine is one of the basic and important elements in biology, as it serves as a building block for proteins. Three polymorphic forms with different physical properties are possible in glycine (α, β and γ), Of special interest for various applications are non-centrosymmetric polymorphs: β-glycine and γ-glycine. The most useful β-polymorph being ferroelectric took much less attention than the other due to its instability under ambient conditions. In this work, we could grow stable microcrystals of β-glycine by the evaporation of aqueous solution on a (111)Pt/Ti/SiO2/Si substrate as a template. The effects of the solution concentration and Pt-assisted nucleation on the crystal growth and phase evolution were characterized by X-ray diffraction analysis and Raman spectroscopy. In addition, spin-coating technique was used for the fabrication of highly aligned nano-islands of β-glycine with regular orientation of the crystallographic axes relative the underlying substrate (Pt). Further we study both as-grown and tip-induced domain structures and polarization switching in the β-glycine molecular systems by Piezoresponse Force Microscopy (PFM) and compare the results with molecular modeling and computer simulations. We show that β-glycine is indeed a room-temperature ferroelectric and polarization can be switched by applying a bias to non-polar cuts via a conducting tip of atomic force microscope (AFM). Dynamics of these in-plane domains is studied as a function of applied voltage and pulse duration. The domain shape is dictated by both internal and external polarization screening mediated by defects and topographic features. Thermodynamic theory is applied to explain the domain propagation induced by the AFM tip. Our findings suggest that β-glycine is a uniaxial ferroelectric with the properties controlled by the charged domain walls which in turn can be manipulated by external bias. Besides, nonlinear optical properties of β-glycine were investigated by a second harmonic generation (SHG) method. SHG method confirmed that the 2-fold symmetry is preserved in as-grown crystals, thus reflecting the expected P21 symmetry of the β-phase. Spontaneous polarization direction is found to be parallel to the monoclinic [010] axis and directed along the crystal length. These data are confirmed by computational molecular modeling. Optical measurements revealed also relatively high values of the nonlinear optical susceptibility (50% greater than in the z-cut quartz). The potential of using stable β-glycine crystals in various applications are discussed in this work.

As bibliotecas escolares e a literacia da informação : um projeto numa turma de 2º ciclo

Trabalho de projeto de mestrado, Educação (Especialidade em Educação e Tecnologias Digitais), Universidade de Lisboa, Instituto de Educação, 2014

Uma avaliação do processo de constituição e desenvolvimento de um observatório num agrupamento de escolas

Dissertação de mestrado, Ciências da Educação (Avaliação em Educação), Universidade de Lisboa, Instituto de Educação, 2014

Identifying and explaining framing strategies of low carbon lifestyle movement organisations

Over the last decade we have seen the growth and development of low carbon lifestyle movement organisations, which seek to encourage members of the public to reduce their personal energy use and carbon emissions. As a first step to assess the transformational potential of such organisations, this paper examines the ways in which they frame their activities. This reveals an important challenge they face: in addressing the broader public, do they promote ‘transformative’ behaviours or do they limit themselves to encouraging ‘easy changes’ to maintain their appeal? We find evidence that many organisations within this movement avoid ‘transformative’ frames. The main reasons for this are organisers’ perceptions that transformational frames lack resonance with broader audiences, as well as wider cultural contexts that caution against behavioural intervention. The analysis draws on interviews with key actors in the low carbon lifestyle movement and combines insights from the literatures on collective action framing and lifestyle movements.

Gold, power, protest: Digital and social media and protests against large-scale mining projects in Colombia

Colombia’s Internet connectivity has increased immensely. Colombia has also ‘opened for business’, leading to an influx of extractive projects to which social movements object heavily. Studies on the role of digital media in political mobilisation in developing countries are still scarce. Using surveys, interviews, and reviews of literature, policy papers, website and social media content, this study examines the role of digital and social media in social movement organisations and asks how increased digital connectivity can help spread knowledge and mobilise mining protests. Results show that the use of new media in Colombia is hindered by socioeconomic constraints, fear of oppression, the constraints of keyboard activism and strong hierarchical power structures within social movements. Hence, effects on political mobilisation are still limited. Social media do not spontaneously produce non-hierarchical knowledge structures. Attention to both internal and external knowledge sharing is therefore conditional to optimising digital and social media use.

A generic model for integration of Quality, Environment and Safety Management Systems

Purpose – The purpose of this paper is to propose a generic model of Integrated Management System of Quality, Environment and Safety (IMS-QES) that can be adapted and progressively to assimilate various Management Systems, of which highlights: ISO 9001 for Quality; ISO 14001 for Environment; OHSAS 18001 for Occupational Health and Safety. Design/methodology/approach – The model was designed in the real environment of a Portuguese Organization and 160 employees were surveyed. The rate response was equal to 86 percent. The conceived model was implemented in a first phase for the integration of Quality, Environment and Safety Management Systems. Findings – Among the main findings of the survey the paper highlights: the elimination of conflicts between individual systems with resources optimization; creation of added value to the business by eliminating several types of wastes; the integrated management of sustainability components in a global market; the improvement of partnerships with suppliers of goods and services; reducing the number of internal and external audits. Originality/value – This case study is one of the first Portuguese empirical researches about IMS-QES and the paper believes that it can be useful in the creation of a Portuguese guideline for integration, namely the Quality Management Systems; Environmental Management Systems and Occupational Health and Safety Management Systems among others.

Chaînes opératoires and resource-exploitation strategies in chimpanzee (Pan troglodytes) nut cracking

Journal of Human Evolution, V. 55, pp. 148-163

Identidade visual corporativa enquanto recurso estratégico na competitividade entre organizações em Portugal

Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Publicidade e Marketing.

Business continuity management at Banif: Defining and selecting recovery strategies

This project aims to delineate recovery strategies for a Portuguese Bank, as a way to increase its preparedness towards unexpected disruptive events, thus avoiding an operational crisis escalation. For this purpose, Business Continuity material was studied, a risk assessment performed, a business impact analysis executed and new strategic framework for selecting strategies adopted. In the end, a set of recovery strategies were chosen that better represented the Bank’s appetite for risk, and recommendations given for future improvements.

Carry and trend-following strategies

Recent research has shown that carry and trend strategies when combined lead to significant risk-adjusted returns that can be very attractive to investors, at a low cost with small and positive skewness. This study proposes to combine both carry and trend-following, considering a data set of ten years (09/2005-09/2015), within a portfolio composed by three major asset classes: currencies, commodities and equity indices. Following a futures-based methodology, the obtained results show that, indeed, the strategy results inevitably in higher returns and greater sharpe ratios for every asset class in study. This outcome results from the fact that trend proved to provide a significant hedge to the downside risk that carry is exposed to.

Static and dynamic shoulder stabilizer adaptations in javelin throwers: A preliminary study

BACKGROUND: Adaptations to Internal (IR) and external (ER) rotator shoulder muscles improving overhead throwing kinematics could lead to muscular strength imbalances and be considered an intrinsic risk factor for shoulder injury, as well as modified shoulder range of motion (RoM). OBJECTIVE: To establish profiles of internal and external rotation RoM and isokinetic IR and ER strength in adolescent- and national-level javelin throwers. METHODS: Fourteen healthy subjects were included in this preliminary cross-sectional study, 7 javelin throwers (JTG) and 7 nonathletes (CG). Passive internal and external rotation RoM were measured at 90 degrees of shoulder abduction. Isokinetic strength of dominant and non-dominant IR and ER was evaluated during concentric (60, 120 and 240 degrees/s) and eccentric (60 degrees/s) contractions by Con-Trex (R) dynamometer with the subject in a seated position with 45 degrees of shoulder abduction in the scapular plane. RESULTS: We reported significantly lower internal rotation and significantly higher external rotation RoM in JTG than in CG. Concentric and eccentric IR and ER strength were significantly higher for the dominant shoulder side in JTG (P < 0.05), without significant differences in ER/IR ratios. CONCLUSIONS: The main finding of this preliminary study confirmed static and dynamic shoulder stabilizer adaptations due to javelin throw practice in a population of adolescent- and national-level javelin throwers.

An investigation into the physical and psychological stress factors that elementary teachers experience : recommendations to boards and personal calming strategies /

The prlmaiy objective of this study was to Identify and describe the physical and psychological stress factors that elementary school teachers experience and how teachers cope with stress. A secondary objective was to offer boards and teachers potential coping strategies counteracting stress and the effects of stress. The sample consisted of 120 elementaiy teachers from southern Ontario. Ten elementaiy schools were randomly chosen. The Teacher Stress Inventory questionnaire (Flmian, 1989) was used. Data were analyzed using a variety of statistics. Test norms and interpretations were performed based on standard results obtained from the author of the questionnaire (Flmian, 1988). Overall, the results indicated that work-related stressors were the main factor for teacher stress. This Included such factors as caseload/class is too big, too much administrative paperwork, and having little time to prepare lessons. Implications for further research and practical suggestions for further reseairch are discussed. Also a variety of recommendations to boards and for individual use are discussed. Some recommendations are having counselling available for teachers, workshops on how to handle stress, and learning how to breathe and using calm visualization.

Transition into the teaching profession: induction and mentoring issues surrounding secondary music teachers /

The purpose of this study was to investigate the issues surrounding the transition into the teaching profession by specifically focusing on teacher induction and mentoring issues while explicitly addressing matters of concern by secondary music teachers in a large suburban school board in southern Ontario. Participants included beginning teachers with fewer than 5 years of teaching, mid career teachers with between 6 and 15 years of instruction, and experienced teachers with more than 16 years of practice. The ' processes of mentoring and inducting new teachers within the board were examined, along with their relationships between proteges, mentors, and administrators. Further, internal and external programs specifically designed and implemented for newer music teachers were scrutinized and discussed. An analysis of key documents and literature on the subject was performed, and data were collected through 16 personal interviews. The findings suggest that although the necessity of mentoring and induction processes has begun to be recognized, there exists a fundamental relationship between mentoring and induction and the effect of the professional attachments to mentoring; the institutional and administrative supports that are enabled; and essential processes and practices between mentors and proteges. Together these three arms combine to support successfiil induction and mentoring initiatives that will help ease the transition into teaching.

Preoperative education and its influence on perception of recovery for clients awaiting total hip and total knee replacement surgery /

The puqjose of this study was to examine the manner in which an inviting approach to a preoperative teaching and learning educational experience influenced the perception and subsequent recovery of clients who were awaiting total hip and total knee replacement surgery. An in-depth review of the internal and external factors that shape client perceptions was undertaken in this study. In addition, this study also explored whether or not the Prehab Program was preparing clients physically, socially, and psychologically for surgery. Data for this qualitative case study research were collected through preoperative interviews with 4 participants awaiting total hip replacement surgery and 1 participant awaiting total knee replacement surgery. Four postoperative interviews were conducted with the participants who had received total hip replacement surgery. The occupational therapist and physical therapist who were the coleaders of the Prehab Program at the time of this study were also interviewed. The results of this study suggest that while individuals may receive similar educational experiences, their perceptions of the manner in which they benefited from these experiences varied. This is illustrated in the research findings, which concluded that while clients benefited physically from the inviting approach used during the practical teaching session, not all clients perceived the psychological benefits of this practice session, especially clients with preexisting high levels of anxiety. In addition to increasing the understanding of the internal as well as external factors that influence the perceptions of clients, this study has also served as an opportunity for reflection on practice for the Prehab therapists and other healthcare educators.

A Study of role conflict, role ambiguity, locus of control, job satisfaction and participation in decision making among front-line vocational service workers for mentally retarded adults

This study was an investigation of individual and organizational factors, as perceived by front-line vocational service workers from Adult Rehabilitation Centres (ARC Industries) for mentally retarded adults. The specific variables which were measured included role conflict/role ambiguity (role factors), internal/external locus of control (individual differences), job satisfaction with work and supervision (job attitudes) and participation in deci~ion making (organizational factor). The exploration of these constructs was conducted by means of self-report questionnaires which were completed by sixty-nine out of a total of ninety front-line employees. The surveys were distributed in booklet form to nine distinct rehabilitation facilities from St. Catharines, West Lincoln, Greater Niagara, Port Colborne, WeIland, Fort Erie, Hamilton, Guelph and Brantford. The survey data was evaluated by the statisti.cal Package for the Social Sciences (SPSS) which used the Pearson Product Moment Correlation procedure and a compar~son of means test. A comparison of correlation coefficients test was also conducted. This statistical procedure was calculated mathematically. The results obtained from the statistical evaluation confirmed the prediction that self-reported measures of participation in decision making and satisfaction (work and supervision) would be negatively correlated with role conflict and role ambiguity. As well, the speculation that perceived satisfaction (work and supervision) would be positively correlated with participation in decision making was empirically supported. Internal and external locus of control did not contribute to a significant difference in r~sponses to role perceptions (conflict and ambiguity) , satisfaction (work and supervision) or the correlational relationship between participation in decision making and satisfaction (work and supervision). Overall, the findings from this study substantiated the importance of examining employee perceptions in the workplace and the interrelationships among individual and organizational variables. This research was considered a contribution to the general area of occupational stress and to the study of individuals in work organizations.