959 resultados para Higher cutting conditions
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The silvopastoral system is a viable technological alternative to extensive cattle grazing, however, for it to be successful, forage grass genotypes adapted to reduced light need to be identified. The objective of this study was to select progenies of Panicum maximum tolerant to low light conditions for use in breeding programs and to study the genetic control and performance of some traits associated with shade tolerance. Six full-sib progenies were evaluated in full sun, 50% and 70% of light reduction in pots and subjected to cuttings. Progeny genotypic values (GV) increased with light reduction in relation to plant height (H) and specific leaf area (SLA). The traits total dry mass accumulation (DM) and leaf dry mass accumulation (LDM) had GV higher in 50% shade and intermediate in 70% shade. The GV of tiller number (TIL) and root dry mass accumulation (RDM) decreased with light reduction. The highest positive correlations were obtained for the traits H and RDM with SLA and DM; the highest negative correlations were between TIL and SLA and RDM, and H and LDM. The progenies showed higher tolerance to 50% light reduction and, among them, two stood out and will be used in breeding programs. It was also found that it is not necessary to evaluate some traits under all light conditions. All traits had high broad sense heritability and high genotypic correlation between progenies in all light intensities. There is genetic difference among the progenies regarding the response to different light intensities, which will allow selection for shade tolerance
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Nowadays, with the use of technology and the Internet, education is undergoing significant changes, contemplating new ways of teaching and learning. One of the widely methods of teaching used to promote knowledge, consists in the use of virtual environments available in various formats, taking as example the teaching-learning platforms, which are available online. The Internet access and use of Laptops have created the technological conditions for teachers and students can benefit from the diversity of online information, communication, collaboration and sharing with others. The integration of Internet services in the teaching practices can provide thematic, social and digital enrichment for the agents involved. In this paper we will talk about the advantages of LMS (Learning Management Systems) such as Moodle, to support the presential lectures in higher education. We also will analyse its implications for student support and online interaction, leading educational agents to a mixing of different learning environments, where they can combine face-to-face instruction with computer-mediated instruction, blended-learning, and increases the options for better quality and quantity of human interaction in a learning environment. We also will present some tools traditionally used in online assessment and that are part of the functionalities of Moodle. These tools can provide interesting alternatives to promote a more significant learning and contribute to the development of flexible and customized models of an evaluation which we want to be more efficient.
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Qualidade é a palavra de ordem pelo qual se regem todos os processos e intervenções da REFER (Rede Ferroviária Nacional). Com a evolução de requisitos exigidos pelo transporte em caminho de ferro, há que procurar sempre as últimas inovações, para que a circulação se faça sempre com maior segurança e comodidade, dando aos utilizadores deste tipo transporte uma qualidade extrema. Nos últimos anos esses requisitos tornaram-se cada vez mais exigentes, pois as condições de circulação aumentam tais como a prática de maiores velocidades, tonelagem e frequência das composições, o que leva a um maior rigor nos processos construtivos e conservativos das vias. A REFER, depois de grandes investimentos em novas infraestruturas ferroviárias, detém agora um decisivo e importante papel na resolução das problemáticas que emergem, apostando sempre em tecnologia de ponta para que possa desenvolver um trabalho de conservação que satisfaça todas as necessidades exigidas. Este trabalho desenvolver-se-á nesta ótica de conservação e manutenção, acompanhando todo um processo específico de ataque mecânico pesado, até à sua certificação. A análise dos vários processos caracterizará a exigência referida na manutenção, principalmente da via moderna, onde a fasquia de requisitos é mais elevada.
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OBJECTIVE To analyze the temporal evolution of the hospitalization of older adults due to ambulatory care sensitive conditions according to their structure, magnitude and causes. METHODS Cross-sectional study based on data from the Hospital Information System of the Brazilian Unified Health System and from the Primary Care Information System, referring to people aged 60 to 74 years living in the state of Rio de Janeiro, Souhteastern Brazil. The proportion and rate of hospitalizations due to ambulatory care sensitive conditions were calculated, both the global rate and, according to diagnoses, the most prevalent ones. The coverage of the Family Health Strategy and the number of medical consultations attended by older adults in primary care were estimated. To analyze the indicators’ impact on hospitalizations, a linear correlation test was used. RESULTS We found an intense reduction in hospitalizations due to ambulatory care sensitive conditions for all causes and age groups. Heart failure, cerebrovascular diseases and chronic obstructive pulmonary diseases concentrated 50.0% of the hospitalizations. Adults older than 69 years had a higher risk of hospitalization due to one of these causes. We observed a higher risk of hospitalization among men. A negative correlation was found between the hospitalizations and the indicators of access to primary care. CONCLUSIONS Primary healthcare in the state of Rio de Janeiro has been significantly impacting the hospital morbidity of the older population. Studies of hospitalizations due to ambulatory care sensitive conditions can aid the identification of the main causes that are sensitive to the intervention of the health services, in order to indicate which actions are more effective to reduce hospitalizations and to increase the population’s quality of life.
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Between 2000/01 and 2006/07, the approval rate of a Thermodynamics course in a Mechanical Engineer graduation was 25%. However, a careful analysis of the results showed that 41% of the students chosen not to attend or dropped out, missing the final examination. Thus, a continuous assessment methodology was developed, whose purpose was to reduce drop out, motivating students to attend this course, believing that what was observed was due, not to the incapacity to pass, but to the anticipation of the inevitability of failure by the students. If, on one hand, motivation is defined as a broad construct pertaining to the conditions and processes that account for the arousal, direction, magnitude, and maintenance of effort, on the other hand, assessment is one of the most powerful tools to change the will that students have to learn, motivating them to learn in a quicker and permanent way. Some of the practices that were implemented, included: promoting learning goal orientation rather than performance goal orientation; cultivating intrinsic interest in the subject and put less emphasis on grades but make grading criteria explicit; emphasizing teaching approaches that encourage collaboration among students and cater for a range of teaching styles; explaining the reasons for, and the implications of, tests; providing feedback to students about their performance in a form that is non-egoinvolving and non-judgemental and helping students to interpret it; broadening the range of information used in assessing the attainment of individual students. The continuous assessment methodology developed was applied in 2007/08 and 2008/09, having found an increase in the approval from 25% to 55% (30%), accompanied by a decrease of the drop out from 41% to 23,5% (17,5%). Flunking with a numerical grade lowered from 34,4% to 22,0% (12,4%). The perception by the students of the continuous assessment relevance was evaluated with a questionnaire. 70% of the students that failed the course respond that, nevertheless, didn’t repent having done the continuous assessment.
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The use of Laptops and the Internet has produced the technological conditions for instructors and students can take advantage from the diversity of online information, communication, collaboration and sharing with others. The integration of Internet services in the teaching practices can be responsible for thematic, social and digital improvement for the agents involved. There are many benefits when we use a Learning Management Systems (LMS) such as Moodle, to support the lectures in higher education. We also will consider its implications for student support and online interaction, leading educational agents to a collaborating of different learning environments, where they can combine face-to-face instruction with computer-mediated instruction, blended-learning, and increases the possibilities for better quality and quantity of human communication in a learning background. In general components of learning management systems contain synchronous and asynchronous communication tools, management features, and assessment utilities. These assessment utilities allow lecturers to systematize basic assessment tasks. Assessments can be straightaway delivered to the student, and upon conclusion, immediately returned with grades and detailed feedback. Therefore learning management systems can also be used for assessment purposes in Higher Education.
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The aim of this work was to assess the influence of meteorological conditions on the dispersion of particulate matter from an industrial zone into urban and suburban areas. The particulate matter concentration was related to the most important meteorological variables such as wind direction, velocity and frequency. A coal-fired power plant was considered to be the main emission source with two stacks of 225 m height. A middle point between the two stacks was taken as the centre of two concentric circles with 6 and 20 km radius delimiting the sampling area. About 40 sampling collectors were placed within this area. Meteorological data was obtained from a portable meteorological station placed at approximately 1.7 km to SE from the stacks. Additional data was obtained from the electrical company that runs the coal power plant. These data covers the years from 2006 to the present. A detailed statistical analysis was performed to identify the most frequent meteorological conditions concerning mainly wind speed and direction. This analysis revealed that the most frequent wind blows from Northwest and North and the strongest winds blow from Northwest. Particulate matter deposition was obtained in two sampling campaigns carried out in summer and in spring. For the first campaign the monthly average flux deposition was 1.90 g/m2 and for the second campaign this value was 0.79 g/m2. Wind dispersion occurred predominantly from North to South, away from the nearest residential area, located at about 6 km to Northwest from the stacks. Nevertheless, the higher deposition fluxes occurred in the NW/N and NE/E quadrants. This study was conducted considering only the contribution of particulate matter from coal combustion, however, others sources may be present as well, such as road traffic. Additional chemical analyses and microanalysis are needed to identify the source linkage to flux deposition levels.
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This article reports preliminary findings about Portuguese scientist women’s perceptions of gender issues in their institutions. Empirical data have been collected by means of an electronic open questionnaire sent to the AMONET (Portuguese Association of Women in Science) members. Basically, the study aims to examine the degree of satisfaction with their profession, the difficulties they meet in everyday professional life, and whether they feel or have felt gender discrimination in their institutions. Findings show that all respondents feel happy or very happy with their profession. However, discrimination is mentioned by a significant percentage, even if such discrimination assumes, quite often, an elusive way, suggesting that higher institutions still discriminate against women. Findings, articulated with literature, also lead to discussion about power and leadership, both in the hands of male academics, in the majority of the institutions, as well as the clarification of different perceptions of ambition both by women and man.
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Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Área de especialização: Intervenção cardiovascular
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Functionally graded composite materials can provide continuously varying properties, which distribution can vary according to a specific location within the composite. More frequently, functionally graded materials consider a through thickness variation law, which can be more or less smoother, possessing however an important characteristic which is the continuous properties variation profiles, which eliminate the abrupt stresses discontinuities found on laminated composites. This study aims to analyze the transient dynamic behavior of sandwich structures, having a metallic core and functionally graded outer layers. To this purpose, the properties of the particulate composite metal-ceramic outer layers, are estimated using Mod-Tanaka scheme and the dynamic analyses considers first order and higher order shear deformation theories implemented though kriging finite element method. The transient dynamic response of these structures is carried out through Bossak-Newmark method. The illustrative cases presented in this work, consider the influence of the shape functions interpolation domain, the properties through-thickness distribution, the influence of considering different materials, aspect ratios and boundary conditions. (C) 2014 Elsevier Ltd. All rights reserved.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Química e Bioquímica
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This study aimed to examine the differences in standing balance between individuals with Parkinson's disease (PD) and subjects without PD (control group), under single and dual-task conditions. A cross-sectional study was designed using a non-probabilistic sample of 110 individuals (50 participants with PD and 60 controls) aged 50 years old and over. The individuals with PD were in the early or middle stages of the disease (characterized by Hoehn and Yahr as stages 1-3). The standing balance was assessed by measuring the centre of pressure (CoP) displacement in single-task (eyes-open/eyes-closed) and dual-task (while performing two different verbal fluency tasks). No significant differences were found between the groups regarding sociodemographic variables. In general, the standing balance of the individuals with PD was worse than the controls, as the CoP displacement across tasks was significantly higher for the individuals with PD (p<0.01), both in anteroposterior and mediolateral directions. Moreover, there were significant differences in the CoP displacement based parameters between the conditions, mainly between the eyes-open condition and the remaining conditions. However, there was no significant interaction found between group and condition, which suggests that changes in the CoP displacement between tasks were not influenced by having PD. In conclusion, this study shows that, although individuals with PD had a worse overall standing balance than individuals without the disease, the impact of performing an additional task on the CoP displacement is similar for both groups.
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The opto-electronic properties of copper zinc tin sulfide can be tuned to achieve better cell efficiencies by controlled incorporation of selenium. In this paper we report the growth of Cu2ZnSn(S,Se)4 (CZTSSe) using a hybrid process involving the sequential evaporation of Zn and sputtering of the sulfide precursors of Cu and Sn, followed by a selenization step. Two approaches for selenization were followed, one using a tubular furnace and the other using a rapid thermal processor. The effects of annealing conditions on the morphological and structural properties of the films were investigated. Scanning electron microscopy and energy dispersive spectroscopy were employed to investigate the morphology and composition of the films. Structural analyses were done using X-ray diffraction (XRD) and Raman spectroscopy. Structural analyses revealed the formation of CZTSSe. This study shows that regardless of the selenization method a temperature above 450 °C is required for conversion of precursors to a compact CZTSSe layer. XRD and Raman analysis suggests that the films selenized in the tubular furnace are selenium rich whereas the samples selenized in the rapid thermal processor have higher sulfur content.
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This report describes the prevalence of anti-HAV antibodies in children from elementary school in the Municipality of Vila Velha, ES, Brazil. Anti-HAV antibodies were investigated by ELISA method in the serum of 606 children (four to fourteen years old) from three elementary schools, located in neighborhoods with varying household monthly income levels: São José School, 200 chidren, household income higher than US$700; São Torquato School, 273 children, US$200 to 300; and Cobi School, 133 children, less than US$200. From each children data on age, gender, skin color, sanitary conditions, frequency of contact with sea or river water and family history of hepatitis were recorded. Anti-HAV antibodies were present in 38.6% of all children, 9% in São José School, 49.1% in São Torquato School and 61.7% in Cobi School. Logistic regression analysis demonstrated a positive correlation of positive anti-HAV test with age, non white color of the skin, absence of sewage treatment and domestic water filter, and a past history of hepatitis. The prevalence of anti-HAV antibodies in school children in Vila Velha, ES, was lower than that observed in the same age group in North and Northeast Brazil and was significantly higher in children from families with low socioeconomic status. In addition the results indicate a changing epidemiologic pattern of hepatitis A in our country, with an increasing number of children and adolescents with high risk for HAV infection, mainly in high socioeconomic class. A consideration must be given to the feasibility of vaccination programs for children and adolescents in our country.
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Enhanced biological phosphorus removal (EBPR) is the most economic and sustainable option used in wastewater treatment plants (WWTPs) for phosphorus removal. In this process it is important to control the competition between polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), since EBPR deterioration or failure can be related with the proliferation of GAOs over PAOs. This thesis is focused on the effect of operational conditions (volatile fatty acid (VFA) composition, dissolved oxygen (DO) concentration and organic carbon loading) on PAO and GAO metabolism. The knowledge about the effect of these operational conditions on EBPR metabolism is very important, since they represent key factors that impact WWTPs performance and sustainability. Substrate competition between the anaerobic uptake of acetate and propionate (the main VFAs present in WWTPs) was shown in this work to be a relevant factor affecting PAO metabolism, and a metabolic model was developed that successfully describes this effect. Interestingly, the aerobic metabolism of PAOs was not affected by different VFA compositions, since the aerobic kinetic parameters for phosphorus uptake, polyhydroxyalkanoates (PHAs) degradation and glycogen production were relatively independent of acetate or propionate concentration. This is very relevant for WWTPs, since it will simplify the calibration procedure for metabolic models, facilitating their use for full-scale systems. The DO concentration and aerobic hydraulic retention time (HRT) affected the PAO-GAO competition, where low DO levels or lower aerobic HRT was more favourable for PAOs than GAOs. Indeed, the oxygen affinity coefficient was significantly higher for GAOs than PAOs, showing that PAOs were far superior at scavenging for the often limited oxygen levels in WWTPs. The operation of WWTPs with low aeration is of high importance for full-scale systems, since it decreases the energetic costs and can potentially improve WWTP sustainability. Extended periods of low organic carbon load, which are the most common conditions that exist in full-scale WWTPs, also had an impact on PAO and GAO activity. GAOs exhibited a substantially higher biomass decay rate as compared to PAOs under these conditions, which revealed a higher survival capacity for PAOs, representing an advantage for PAOs in EBPR processes. This superior survival capacity of PAOs under conditions more closely resembling a full-scale environment was linked with their ability to maintain a residual level of PHA reserves for longer than GAOs, providing them with an effective energy source for aerobic maintenance processes. Overall, this work shows that each of these key operational conditions play an important role in the PAO-GAO competition and should be considered in WWTP models in order to improve EBPR processes.