Computer simulations of copper and gold nanowires and single-wall nanowires

Copper and gold nanowires under tension evolve to form linear atomic chains (LACs), and the study and understanding of this evolution is an important subject for the development of nanocontacts. Here we study the differences and similarities between copper and gold nanowires (NWs) under stress along the [111] crystallographic direction until their rupture using tight-binding molecular dynamics. In both metals, the first significant rearrangement occurs due to one inside atom that goes to the NW` surface. In an attempt to better understand this effect, for both metals we also consider hollow NW`s where the inside atoms were excluded after the initial relaxation to create single-wall NW`s (SWNWs). The dynamical evolution of these SWNWs provides insight on the formation of the constriction that evolves to form LACs. Studying the calculated forces supported by the NW`s we show that SWNWs can sustain larger forces before the first major rearrangement in the copper and gold when compared to the original NW`s.

Is the unfolding of the group discussion off-pattern? Improving coordination support in educational forums using mobile devices

A forum is a valuable tool to foster reflection in an in-depth discussion; however, it forces the course mediator to continually pay close attention in order to coordinate learners` activities. Moreover, monitoring a forum is time consuming given that it is impossible to know in advance when new messages are going to be posted. Additionally, a forum may be inactive for a long period and suddenly receive a burst of messages forcing forum mediators to frequently log on in order to know how the discussion is unfolding to intervene whenever it is necessary. Mediators also need to deal with a large amount of messages to identify off-pattern situations. This work presents a piece of action research that investigates how to improve coordination support in a forum using mobile devices for mitigating mediator`s difficulties in following the status of a forum. Based on summarized information extracted from message meta-data, mediators consult visual information summaries on PDAs and receive textual notifications in their mobile phone. This investigation revealed that mediators used the mobile-based coordination support to keep informed on what is taking place within the forum without the need to log on their desktop computer. (C) 2009 Elsevier Ltd. All rights reserved.

Ethanol electro-oxidation on carbon-supported Pt-Ru, Pt-Rh and Pt-Ru-Rh nanoparticles

This work investigates the effects of carbon-supported Pt, Pt-Ru, Pt-Rh and Pt-Ru-Rh alloy electrocatalysts oil the yields of CO2 and acetic acid as electro-oxidation products of ethanol. Electronic and structural features of these metal alloys were studied by in situ X-ray absorption spectroscopy (XAS). The electrochemical activity was investigated by polarization experiments and the reaction intermediates and products were analyzed by in situ Fourier Transform Infra-Red Spectroscopy (FTIR). Electrochemical stripping of CO. which is one of the adsorbed intermediates, presented a faster oxidation kinetics on the Pt-Ru electrocatalyst, and similar rates of reaction on Pt-Rh and Pt. The electrochemical current of ethanol oxidation showed a higher value and the onset potential was less positive oil Pt-Ru. However, in situ FTIR spectra evidenced that the CO2/acetic acid ratio is higher for the materials with Rh, mainly at lower potentials. These results indicate that the Ru atoms act mainly by providing oxygenated species for the oxidation of ethanol intermediates, and point out ail important role of Rh on the C-C bond dissociation. (C) 2007 Elsevier Ltd. All rights reserved.

On Occurrence Of Plagiarism In Published Computer Science Thesis Reports At Swedish Universities

In recent years, it has been observed that software clones and plagiarism are becoming an increased threat for one?s creativity. Clones are the results of copying and using other?s work. According to the Merriam – Webster dictionary, “A clone is one that appears to be a copy of an original form”. It is synonym to duplicate. Clones lead to redundancy of codes, but not all redundant code is a clone.On basis of this background knowledge ,in order to safeguard one?s idea and to avoid intentional code duplication for pretending other?s work as if their owns, software clone detection should be emphasized more. The objective of this paper is to review the methods for clone detection and to apply those methods for finding the extent of plagiarism occurrence among the Swedish Universities in Master level computer science department and to analyze the results.The rest part of the paper, discuss about software plagiarism detection which employs data analysis technique and then statistical analysis of the results.Plagiarism is an act of stealing and passing off the idea?s and words of another person?s as one?s own. Using data analysis technique, samples(Master level computer Science thesis report) were taken from various Swedish universities and processed in Ephorus anti plagiarism software detection. Ephorus gives the percentage of plagiarism for each thesis document, from this results statistical analysis were carried out using Minitab Software.The results gives a very low percentage of Plagiarism extent among the Swedish universities, which concludes that Plagiarism is not a threat to Sweden?s standard of education in computer science.This paper is based on data analysis, intelligence techniques, EPHORUS software plagiarism detection tool and MINITAB statistical software analysis.

Effects of computer reminders on complications of peripheral venous catheters and nurses' adherence to a guideline in paediatric care : a cluster randomised study

BACKGROUND: Reminder systems in electronic patient records (EPR) have proven to affect both health care professionals' behaviour and patient outcomes. The aim of this cluster randomised trial was to investigate the effects of implementing a clinical practice guideline (CPG) for peripheral venous catheters (PVCs) in paediatric care in the format of reminders integrated in the EPRs, on PVC-related complications, and on registered nurses' (RNs') self-reported adherence to the guideline. An additional aim was to study the relationship between contextual factors and the outcomes of the intervention. METHODS: The study involved 12 inpatient units at a paediatric university hospital. The reminders included choice of PVC, hygiene, maintenance, and daily inspection of PVC site. Primary outcome was documented signs and symptoms of PVC-related complications at removal, retrieved from the EPR. Secondary outcome was RNs' adherence to a PVC guideline, collected through a questionnaire that also included RNs' perceived work context, as measured by the Alberta Context Tool. Units were allocated into two strata, based on occurrence of PVCs. A blinded simple draw of lots from each stratum randomised six units to the control and intervention groups, respectively. Units were not blinded. The intervention group included 626 PVCs at baseline and 618 post-intervention and the control group 724 PVCs at baseline and 674 post-intervention. RNs included at baseline were 212 (65.4 %) and 208 (71.5 %) post-intervention. RESULTS: No significant effect was found for the computer reminders on PVC-related complications nor on RNs' adherence to the guideline recommendations. The complication rate at baseline and post-intervention was 40.6 % (95 % confidence interval (CI) 36.7-44.5) and 41.9 % (95 % CI 38.0-45.8), for the intervention group and 40.3 % (95 % CI 36.8-44.0) and 46.9 % (95 % CI 43.1-50.7) for the control. In general, RNs' self-rated work context varied from moderately low to moderately high, indicating that conditions for a successful implementation to occur were less optimal. CONCLUSIONS: The reminders might have benefitted from being accompanied by a tailored intervention that targeted specific barriers, such as the low frequency of recorded reasons for removal, the low adherence to daily inspection of PVC sites, and the lack of regular feedback to the RNs. TRIAL REGISTRATION: Current Controlled Trials ISRCTN44819426.

O modelo de integração econômico e social nas cooperativas agropecuárias do Paraná

Analisar o modelo de integração das cooperativas de produtores agropecuários no estado do Paraná foi o propósito deste estudo. Foram estudadas as características, os fatores que dificultam e as ações que facilitam a integração entre cooperados e suas cooperativas e destas entre si. As cooperativas têm características distintas dos outros atores do mercado, nos seus objetivos, na forma de gestão, na formação do capital e na sua identificação com a comunidade onde atuam. O desenvolvimento das cooperativas agropecuárias no Paraná é resultante dos Projetos Integrados de Cooperativismo (PICs), implementados a partir de 1972. O modelo previa cooperativas singulares, cada qual com sua área de ação, com o objetivo de proporcionar assistência técnica, creditícia e apoio logístico aos produtores associados, e centrais cooperativas, por região, para industrialização e comercialização da produção. Os resultados proporcionados pelos projetos integrados são evidentes, pois, quase 60% da produção agropecuária atual provém das cooperativas em todo o estado. Porém, ao longo do tempo, em razão do crescimento desigual das cooperativas, surgiram disputas por área de ação entre cooperativas e conflitos de interesses em relação às centrais que comprometeram o modelo de integração idealizado. Pesquisa de campo realizada para este estudo, mostra que 75% das pessoas que compõem o público interno das cooperativas – cooperados, dirigentes e funcionários, concordam que há concorrência entre cooperativas no Paraná. Trata-se de tema polêmico porém relevante para o desenvolvimento do cooperativismo paranaense, que concorre com grandes conglomerados econômicos nacionais e internacionais. A superação do dilema da integração constitui importante desafio às organizações cooperativas. Esta dissertação utiliza metodologia de análise de conteúdo, descrita por VERGARA (2007, p. 15) para extrair da bibliografia e da pesquisa de campo os resultados almejados. Com base na Teoria da Delimitação dos Sistemas Sociais, concebida por Guerreiro Ramos (1981), conclui-se que as cooperativas agropecuárias paranaenses são organizações de interesse econômico que apresentam características isonômicas de gestão. A maioria dos fatores que dificultam a integração nas cooperativas é originada de atitudes internas de cooperados e dirigentes, tais como: individualismo, falta de conhecimento sobre as cooperativas e falta de interesse em participar da cooperativa. Entre as ações que poderiam contribuir para a integração foi citada a necessidade de se constituir novo modelo de integração, apoiado por programas de educação, comunicação e capitalização em volumes compatíveis com as demandas dos projetos das cooperativas, tanto aos cooperados quanto para projetos integrados entre cooperativas.

tCAD: a 3D modeling application on a depth enhanced tabletop computer

Tabletop computers featuring multi-touch input and object tracking are a common platform for research on Tangible User Interfaces (also known as Tangible Interaction). However, such systems are confined to sensing activity on the tabletop surface, disregarding the rich and relatively unexplored interaction canvas above the tabletop. This dissertation contributes with tCAD, a 3D modeling tool combining fiducial marker tracking, finger tracking and depth sensing in a single system. This dissertation presents the technical details of how these features were integrated, attesting to its viability through the design, development and early evaluation of the tCAD application. A key aspect of this work is a description of the interaction techniques enabled by merging tracked objects with direct user input on and above a table surface.

Predicting and breaking sedentary behaviour at work

This thesis aimed at designing and developing a system that can a) infer individuals’ need for a break from sedentary behaviour in the workplace, and b) persuade them to take a break through the use of different techniques from persuasive psychology. We postulated three variables, namely, individuals’ posture, stress levels and involvement in their computer mediated activity. We developed and field-studied a system that could infer these using a web camera and a key presses and mouse clicks log. We found that the system could predict posture from viewing depth and stress from the movement detected. We then created a general formula that predicts individuals’ need for a break using only the posture and stress predictors. Once the first objective was set, we built and field-studied a system that used three ways to communicate a recommendation for a break to a user: implicit, just-in time and ambient feedback. The implicit feedback was operationalized through changes in the users’ computer wallpaper that provided subtle visual cues. The just-in time feedback employed prompting at the bottom right side of the user’s screen. In addition, we implemented an intuitive behind-screen interaction technique where people can snooze a notification using simple gestures. The ambient feedback mechanism employed an origami sculpture sitting on the user’s desk. This prototype was continuously reflecting the user’s posture and performed rhythmic movements when to recommend breaks. A field study demonstrated the overall success of the system, with 69% of the break recommendations received by users were accepted. The study further revealed the strengths and weaknesses of the three persuasive mechanisms.

Exploring the dimensions of eco-feedback in the wild

Worldwide reports about energy usage have noted the importance of the domestic energy consumption sector in the worldwide scenario. This fact motivated and supported the birth and spread of the so-called eco-feedback devices. Such devices provide information about individual or group energy consumption behavior with the goal of reducing the impact in the environment. Motivated by the body of work which questions the long term effectiveness of eco-feedback systems, this thesis focus on evaluating in-the-wild the long term usage of eco-feedback systems. We have conducted five long term studies with different eco-feedback systems designed to evaluate different dimensions in the design of eco-feedback plus two more focused short term studies aimed at studying concrete approaches. Our summary reports on the fact that the there is a novelty effect associated with ecofeedback systems in which the usage of these devices declines significantly after a month. We did not found evidence that the novelty effect is related to location or the type of information represented, nor that the decrease in the eco-feedback usage could lead to the consumption relapsing to values previous to the introduction of the eco-feedback. Our work has also generated other contributions related to the positioning of the feedback, using metaphors for representing the consumption and presenting information about the source of the energy in the feedback.

Do lixo à solidariedade : avanços e perspectivas na busca de uma nova realidade

The dissertating study about the solidarity economy has the objective to analyze the four unions responsible for the selective municipal garbage collection in Natal. It aims at verifying the consolidation of these unions as solidarity economic undertakings, revealing which progresses they have made, as well as the social and economic insertion of the garbage collectors and their process of conquering citizenship. The referred four unions had been founded and are constituted, in their majority, by collectors coming from the Cidade Nova lixão (big garbage). As it was closed in August 2004, they decided to make a union in order to collecting garbage. As what concerns the methodic and theoretic proceedings, our research has been developed with a critical perspective and a qualitative approach without discarding and quantitative one. The central analytical categories of this paper are: association, work, social exclusion and citizenship. Our research has had three articulated axis which aim was to apprehend the subject, disclosing it. The exposition of the investigative results is subdivided in four chapters. The first one approaches the main aspects of the crisis of the capital and its reflexes in the world of work. Here we deal with the question the structural unemployment coming as a result of the present economic model, the mains changes verified in the Brazilian work market, as well as levels of unemployment affecting the work market in Natal s metropolitan region. The second chapter treats of the origin, concept and revival in Brazil concerning the tradition of thought and cooperative economic organization, which has recovered the central elements of the associative thought and is nowadays studied in Latin America under the name of solidarity economy. The third chapter deals with embodiment of the collectors unions, its history, appearing and development of each union. The fourth chapter presents the relative dimensions of the analysis categories supported in the reports of institutional actors as well as the perception collectors have about the recyclable stuffs, the way they face the daily life and so on, what brings about the contradictions present in their reality. The final comments sum up the main trends and particularities of the unions researched under the light of the solidarity economy and disclose the real perspectives of social and economic insertion of these collectors and the process they follow to conquest social recognition

Um ambiente de suporte ao trabalho cooperativo com aplicação à telemedicina

This dissertation presents a cooperative virtual multimedia enviroment for employing on time medical Field, using a TCP/IP computer network. The Virtual Diagnosis Room environment make it possible to perform cooperative tasks using classical image processing. Synchronous and assynchronous text conversation (chat) and content markup, in order to produce remote cooperative diagnosis. The dissertation also describes the tool in detail and its functions, that enables the interaction among users, along with implementation detals, contributions and weakness of this work

Estudo de manejo de águas pluviais urbanas na cidade Natal-Rio Grande do Norte

Urban stormwater can be considered as potential water resources as well as problems for the proper functioning of the manifold activities of the city, resulting from inappropriate use and occupation of the soil, usually due to poor planning of the occupation of the development areas, with little care for the environmental aspects of the drainage of surface runoff. As a basic premise, we must seek mechanisms to preserve the natural flow in all stages of development of an urban area, preserving the soil infiltration capacity in the scale of the urban area, comprising the mechanisms of natural drainage, and noting preserving natural areas of dynamic water courses, both in the main channel and in the secondary. They are challenges for a sustainable urban development in a harmonious coexistence of modern developmental, which are consistent with the authoritative economic environmental and social quality. Integrated studies involving the quantity and quality of rainwater are absolutely necessary to achieve understanding and obtaining appropriate technologies, involving both aspects of the drainage problems and aspects of use of water when subjected to an adequate management of surface runoff , for example, the accumulation of these reservoirs in detention with the possibility of use for other purposes. The purpose of this study aims to develop a computer model, adjusted to prevailing conditions of an experimental urban watershed in order to enable the implementation of management practices for water resources, hydrological simulations of quantity and, in a preliminary way, the quality of stormwater that flow to a pond located at the downstream end of the basin. To this end, we used in parallel with the distributed model SWMM data raised the basin with the highest possible resolution to allow the simulation of diffuse loads, heterogeneous characteristics of the basin both in terms of hydrological and hydraulic parameters on the use and occupation soil. The parallel work should improve the degree of understanding of the phenomena simulated in the basin as well as the activity of the calibration models, and this is supported by monitoring data acquired during the duration of the project MAPLU (Urban Stormwater Management) belonging to the network PROSAB (Research Program in Basic Sanitation) in the years 2006 to 2008