Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: This thesis is about the design, simulation and measuring of ultra wide band antennas for use in the Square Kilometre Array (SKA). The SKA is a radio astronomy project with one of the aims of detecting hydrogen particles in deep space. Several thousand antennas over a wide band of frequencies are needed to receive the radiation from these particles. This motivates the need for a low-cost ultra wide band antenna with the focus on the low frequency part of the SKA. In this thesis we present two design strategies: The first design strategy is for a printed LPDA on a substrate and design curves are generated. A scale model was built and measurements did not correlate with simulation results. This is due to manufacturing tolerances and assembly of the pyramidal structure. The second design strategy is for a full scale zig-zag antenna and design curves were also generated. The aim here is to produce a low-cost prototype by using brazing rods for the wire structure and mount it on a wooden frame. A full scale model was built and measurements on the roof produced much interference for the radiation pattern, but the reflection coefficient was good. We suggest doing measurements in an interference free environment in order to achieve the needed results. To conclude we suggest using the zig-zag antenna for the SKA. Some issues do however need more attention as the transformer has some losses, the cross polarisation is probably not good enough and the beamwidth does not reach the specification. We demonstrated a low cost prototype and there is the possibility of low-cost large scale manufacturing but this needs to be addressed. This has however not been analysed as many factors for large scale manufacturing are very difficult to predict beforehand and lies outside the scope of this thesis. / AFRIKAANSE OPSOMMING: Hierdie tesis gaan oor die ontwerp, simulasie en opmeting van ultrawyebandantennas vir gebruik in die SKA ("Square Kilometre Array"). Die SKA is ’n radioastronomie projek met die doel om waterstof partikels op te spoor in die ruimte. Duisende antennas wat oor ’n wye band van frekwensies strek is nodig om die energie van die partikels op te vang. Hieruit is daar ’n aanvraag vir lae-koste ultrawyebandantennas met die fokus op die lae frekwensie deel van die SKA. In hierdie tesis word twee ontwerpstrategieë voorgestel: Die eerste ontwerpstrategie is vir ’n gedrukte logaritmies periodiese dipool reeks (LPDR) op ’n substraat tesame met ontwerpskurwes wat gegenereer word. ’n Skaal model is gebou en die gemete resultate stem nie ooreen met die simulasie nie. Dit kan toegeskryf word aan vervaardigingstoleransies en die aanmekaar sit van die piramide struktuur. Die tweede ontwerpstrategie is vir ’n vol skaal sigsag ("zig-zag") antenna met ontwerpskurwes wat ook gegenereer word. Die doel is om ’n lae-koste prototipe te bou deur sweissoldeerdraad te gebruik vir die draadstruktuur en dan op ’n hout raam te plaas. ’n Vol skaal model is gebou en metings op die dak het baie interferensie veroorsaak vir die stralingsveld, maar tog was die weerkaatskoëffisient goed. Ons stel voor om die metings te herhaal in ’n steuringvrye omgewing om sodoende die korrekte resultate te verkry. Om af te sluit stel ons voor om die sigsag antenna vir die SKA te gebruik. Sekere kwessies soos die transformator wat verlieserig is, die kruispolarisasie wat moontlik nie goed genoeg is nie en die bundelwydte wat nie die spesifikasie haal nie moet nog aandag geniet. Ons het ’n lae-koste prototipe gedemonstreer en daar is die moontlikheid om dit op grootskaalse vervaardiging ook goedkoop te doen, maar dit moet nog uigesorteer word. Dit was wel nie geanaliseer nie, siende dat vele faktore ’n rol speel by grootskaalse vervaardiging wat uiters moeilik is om voor die tyd te voorspel en buite die omvang van die tesis lê.

Thesis (MScFor)--Stellenbosch University 2001. / ENGLISH ABSTRACT: Ackerman PA. 2001. An Investigation into the Shorthaul Transport of Pulpwood in South Africa. M.Sc. in Forestry thesis. University of Stellenbosch. 178 pp Shorthaul transport also known as secondary intermediate transport (SIT), a unique feature of pulpwood transport in South Africa, is an additional transport phase within traditional secondary transport. SIT originates at a roadside landing or depot and terminates at another depot, rail siding or merchandising area (not the final destination). The reason for the addition of SIT into the transport chain is identified as the steady decline of forest road conditions to the extent that highway vehicles are unable to reach roadside landings, necessitating the use of intermediate storage sites, from where the timber is once again loaded and transported to final destination. An industry survey established that the decline of forest road conditions are related to excessively high road densities, insufficient funding for road maintenance/upgrading and the lack of understanding by landowners of the importance of maintaining forest road infrastructure. Total funding, by pulpwood companies on roads have shown an increase of R18.55 million from 1997 to 2000, however, subsequent surveys have indicated, that despite this increase in funding, the forest road conditions continue deteriorating. Of the total annual pulpwood intake of 9.39 million tonnes for 1998, 3.7 million tonnes are subject to SIT. Of this 3.7 million tonnes, 2.5 million tonnes are transported from stump to depot and 1.2 million tonnes are transported from landing to depot. The survey identified the agricultural tractor and semi-trailer as the most favoured transport system between stump or landing and depot, responsible for transporting 2.22 million tonnes annually. For 1998, manual loading and three wheel log loaders accounted for the loading of 0.6 and 2.1 million tonnes respectively of the 3.7 million tonnes subject to SIT. This survey information, assisted by newly developed terminology, was used to develop transport scenarios for the economic analysis of total cost of the different transport phases. A network analysis model and pixel-based geographic information system (GIS) were combined to analyse the various transport scenarios within three study areas in the KwaZulu/Natal Midlands, employing SIT on poor, high-density road networks. The simple pixel-based GIS contained information on the forest road network, surface cover and slopes. The results of the economic analysis highlighted the need for the reduction of road network density and for the improvement of the remaining network. This would eliminate the need for extended primary transport and allow the use of highway vehicles transporting from the compartment roadside to and past plantation exits. Results show an average annual cost penalty to the industry, by maintaining SIT, to be R43.25 million or R8.24/m3 . By not employing SIT the industry will potentially save R4.60 for every tonne of the 9.4 million tonnes consumed by the pulpwood processing plants during 1998. Key words: Network analysis. Pixel-based GIS. Timber transport. Secondary transport. Secondary intermediate transport. Secondary terminal transport. Extended primary transport. Primary transport. Dirichlet tessellations. Shorthaul. Note: Throughout this document a full stop (.) is used as a decimal separator. / AFRIKAANSE OPSOMMING: Ackerman PA. 2001.'n Ondersoek na die kortafstand vervoer van pulphout in Suid- Afrika. MSc in Bosbou tesis. Universiteit van Stellenbosch. 178 pp. sekondere intermediere vervoer (SIV), 'n addisionele vervoer-fase binne tradisionele sekondere houtvervoer, is 'n unieke kenmerk van pulphout vervoer in Suid-Afrika. SIV begin op pad, by 'n spesifieke vak of depot en eindig by 'n ander depot, syspoor of verwerkingsgebied (nie die finale bestemming nie). Aangesien die toestand van bospaaie toenemend verswak en omdat swaarpadvervoer nie langer vakke kan bereik nie, word vervoerkontrakteurs al hoe meer gedwing om van depots gebruik te maak waarheen hout deur middel van SIV vervoer moet word. Die hout word dan weer daar gelaai en na 'n verwerkingsfabriek vervoer deur middel van swaarpadvervoer. 'n Landwye opname het getoon dat die swak toestand van bospaaie toegeskryf kan word aan oormatige paddigthede, onvoldoende befondsing vir die instandhouding/ opgradering van paaie en 'n gebrek aan begrip vir die belangrikheid van die onderhoud van pad infrastruktuu r. Die totale kostes aan padverbeterings en opgraderings in die pulphout bedryf, het van 1997 tot 2000 met R18.55 miljoen toegeneem. Verdere opnames toon egter dat ten spyte van hierdie verhoging in befondsing, die toestand van bospaaie steeds onbevredigend is. Van die totale jaarlikse pulphout inname van 9.39 miljoen ton gedurende 1998, word 3.7 miljoen ton aan SIV blootgestel. Van die volume word 2.5 en 1.2 miljoen ton onderskeidelik vanaf die stomp en pad na depots vervoer. Die opname het ook landboutrekkers met leunwaens ge·identifiseer as die gewildste houtvervoer middel tussen die stomp/pad en depots. Hande-arbeid en driewielbloklaaiers is op hulle beurt verantwoordelik vir die laai van onderskeidelik 0.6 en 2.1 miljoen ton pulphout wat deur middel van SIV vervoer word. Inligting uit die opname ondersteun deur nuutgeskepte vakterminologie, is gebruik om verskillende vervoersisteme vir die ekonomiese analise van totale koste van die verskillende vervoerfases te bereken. 'n Netwerk analise model en pixel gebaseerde GIS is in kombinasie gebruik om verskillende vervoer scenarios in drie areas in Kwa-Zulu Natal te ontleed, wat gebruik maak van SIV op swak bospaaie met hoenetwerkdigthede. Die eenvoudige pixel-gebaseerde GIS het inligting weergegee oor bospadnetwerke, oppervlakbedekking en hellings. Die behoefte aan die vermindering van paddigtheid en die verbetering van bospaaie as sulks, is deur die resultate van die ekonomiese ontleding na vore gebring. Dit sal die behoefte vir uitgebreide primers vervoer uitskakel en die gebruik van tradisionele swaar padvoertuie moontlik maak. Die resultate van hierdie opname toon dat die bedryf addisioneel gemiddeld R43.25 miljoen/jaar of R8.24/m3 betaal vir die 3.7 miljoen ton wat onderhewig is aan SIV. Vir die totale 9.4 miljoen m3 het SIV die maatskappye gedurende 1998 R4.60 meer gekos vir elke m3 wat vervoer was. Sleutelwoorde: Netwerkanalise. Houtvervoer. Sekondere vervoer. sekondere intermediere verveer. Sekondere terminale vervoer. VerJengde prirnere vervoer. Kortafstand vervoer. Pixel-gebaseerde GIS Nota: In hierdie document word deurgans 'n punt (.) gebruik om desimale van heelgetalle te skei.

Past focus in the panel gravity literature has been on multidimensional fixed effects specifications in an effort to accommodate heterogeneity. After introducing fixed effects for each origin- destination dyad and time-period speciffic effects, we find evidence of cross-sectional dependence in flows. We propose a simultaneous dependence gravity model that allows for network dependence in flows, along with computationally efficient MCMC estimation methods that produce a Monte Carlo integration estimate of log-marginal likelihood useful for model comparison. Application of the model to a panel of trade flows points to network spillover effects, suggesting the presence of network dependence and biased estimates from conventional trade flow specifications. / Series: Working Papers in Regional Science

The objective of this project is to link the statistical theory used in the ecological sciences with an actual project that was developed for the South African National Parks Scientific Services. It investigates the changes that have occurred in the herbaceous and woody structure due to the closure of artificial waterpoints; including the impacts that elephants and other herbivores have on the vegetation of the Kruger National Park. This project was designed in conjunction with South African National Parks (SANP) Scientific Services and it is a registered project with this department. The results of this project will be submitted to Scientific Services in accordance with the terms and conditions of a SANP research project. A major concern within the KNP is the declining numbers of rare antelope and numerous projects have been developed to investigate possible ways of halting this decline and thus protecting the heterogeneity of the Kruger National Park. Three different datasets were investigated, covering three aspects of vegetation structure and composition within the KNP. The first investigated the changes that have occurred since the N'washitsumbe enclosure in the Far Northern KNP was fenced off from the rest of the park. The results show that over the 40 years since the enclosure was built, changes have occurred which have resulted in a significant difference in the abundance of Increaser 2 and Decreaser grass species between the inside and the outside of the enclosure. Increaser 2 and Decreaser categories are the result of a grass species classification depending on whether the species thrives or is depressed by heavy grazing. The difference in grass species composition and structure between the inside and the outside of the enclosure indicates that the grazing animals within the KNP have influenced the grass composition in a way that favours the dominant animals. This has resulted in a declining roan antelope population - one of the species that is considered as a 'rare antelope'. Many artificial waterpoints (boreholes and dams) have also been closed throughout the KNP in the hope of resulting in a change in vegetation structure and composition in favour of the roan. Veld condition assessment data for 87 boreholes throughout the Park was analyzed to determine whether the veld in the vicinity is beginning to change towards a more Decreaser dominated sward which would favour the roan. The results were analyzed for the different regions of the Park; and they indicate that changes are becoming evident; however, the results are not particularly conclusive, yet. The majority of the boreholes were closed between 1994 and 1998 which means that not a lot of data were available to be analyzed. A similar study conducted in another 10 years time might reveal more meaningful results. However the results are moving in the direction hoped for by the management of the KNP. The results show that the grass composition has a higher proportion of Decreaser grasses since the closure of the waterpoints, and the grass biomass around these areas has also improved. The results were analyzed on an individual basis; and then on a regional basis as the minimal data meant that the individual analyses did not provide any significant results. A third study was then done on the impact that the rapidly increasing elephant population on the vegetation within the Riparian zone along three rivers in the Far Northern region of the KNP. The riparian zone is an important part of the landscape, in terms of providing food for many animals as well as shade. The elephant population has increased substantially since the termination of the culling program and this means that the feeding requirements of the population has increased which could result in severe damage upon the vegetation, as elephants can be very destructive feeders. The results show surprising differences between the three years of data that were analyzed; however the results indicate that the elephants are targeting specific height ranges of trees when feeding; however they do not seem to consistently target specific tree species. This is positive for the diversity of the Riparian zone as this region is very important both ecologically and aesthetically for the tourists who visit the Park.

A seqüência mesozóica da bacia de Ucayali é a maior produtora de gás e condensado do Peru. A área do trabalho, denominada Grande Camisea, fica na parte sul da bacia e, na atualidade, pertence à companhia Plupetrol Peru Corporation. Neste trabalho, foi aplicado um método de interpretação de perfis de indução em um poço petrolífero no sector San Martin do campo Camisea (QuickLook Interpretation method). O objetivo consiste na caracterização do reservatório de San Martín utilizando um método de interpretação rápida de perfis elétricos e, assim, fornecer uma visão geral no entendimento de parâmetros de poços e reservatórios, de zonas produtivas e suas características petrofísicas de porosidade e de saturação do óleo. Para validar a interpretação, foram utilizadas a descrição geológica de testemunhos e amostras de calha, descrição e informação do sistema petrolífero do campo e a geologia regional da zona de interesse da bacia. Desta forma, foi possível apresentar uma comparação entre os valores obtidos através dos métodos detalhados executados pela Pluspetrol e o método rápido de interpretação aplicado aqui, assim como o desvio entre ambos os resultados. / The Mesozoic sequence of the Ucayali basin is the main producer of gas and condensate of Peru. The work area is called Gran Camisea, located in the south part of the basin, and, in the present time, belongs to the company Plupetrol Peru Corporation. In this work, a well log interpretation method was used in a gas well in San Martin area, part of the Camisea field. The goal is the characterization of the reservoir of San Martín using a Quick Look log interpretation method, and thus to supply a general view in the understanding of well and reservoirs parameters, productive zones and its petrophysics characteristics of porosity and saturation. To validate the interpretation, besides using the geologic description of well cores and cutting sampling, it was used the description and information of the petroleum system of Camisea gas field and its regional geology. It was possible to present a comparison between Pluspetrol values, obtained through detailed methods, and those from the Quick Look log interpretation method used here, as well as an analysis of convergence between both results.

O periódico eletrônico ganha cada vez mais credibilidade no campo da informação científica, e muitas são as iniciativas para a criação de novos periódicos. Contudo, apesar desse crescimento em número, são poucos os estudos que abordam a busca e o uso de informação realizados nas versões eletrônicas destes produtos, assim como o internauta que os acessa. A análise de logs é um método que objetiva identificar as ações dos usuários de um site através da investigação dos arquivos de logs do servidor web. Esse tipo de análise pode auxiliar no levantamento de informações sobre a utilização de um periódico eletrônico, mas poucas foram as pesquisas brasileiras que adotaram este método. Dessa forma, torna-se necessário também avaliar esse método aplicado ao estudo de periódicos. O foco da pesquisa é analisar o comportamento de busca e uso da informação em periódicos científicos eletrônicos por meio da análise de logs da revista Psicologia: reflexão e crítica. Esse trabalho objetiva também levantar as diferentes formas de acesso ao periódico, verificar o número de acessos e sua distribuição pelo território nacional, verificar a freqüência de uso do periódico, verificar os tipos de internauta a visitar o periódico, levantar os padrões de comportamento de busca e uso possíveis. As bases teóricas para essa pesquisa são os conceitos de comportamento de busca e uso da informação, periódico científico eletrônico e visibilidade. A metodologia utilizada é a análise de logs fornecidos pela Scientific Electronic Library Online (SciELO), para a obtenção de dados quantitativos, e entrevistas, para a obtenção de dados qualitativos. Por meio da metodologia aplicada chegou-se a um panorama geral da busca e uso do periódico, onde foram determinadas a freqüência de visitação, quem utiliza, quais suas ações no periódico e a origem desses internautas. Constatou-se também a existência de oito padrões de comportamento informacional, que são as seqüências de ações com maior probabilidade de serem realizadas pelos usuários do periódico. / The electronic journals are increasingly gaining more credibility in the information science field, and there are many initiatives for the creation of new journals. However, despite this growth in quantity, there are only a few studies on the information search and use performed in the electronic version of these products, as well as the user who access them. The log analysis is a method which aims to identify the actions of the users of a site through the investigation of the web server’s log files. This type of analysis can help in obtaining information regarding the use of an electronic journal, but there are only a few Brazilian studies which adopted this method. Hence, it is also necessary to evaluate this methodology applied to the journals study. The focus of this research is to analyze the information search and use behavior in scientific electronic journals through the logs analysis of the journal Psicologia: reflexão e crítica. This work also aims to identify the different forms of accessing the journal, to verify the access number and its distribution in the national territory, to verify the frequency of use of the journal, to verify the types of users that visit the journal, and to identify the patterns of the possible information search and use behavior. The theoretic basis for this research are the concepts of information search and use behavior, scientific electronic journal and visibility. The used methodology is the analysis of the logs provided by the Scientific Electronic Library Online (SciELO), for gathering the quantitative data, and interviews, for gathering the qualitative data. Through the applied methodology we have reached a general view of information search and use behavior in the journal, and in this occasion it was determined the visiting frequency, who uses it, what were his/her actions in the journal and the origin of there users. It was also identified the existence of eight patterns of informational behavior, which are the sequences of actions with the biggest probability of being performed by the users of the journal.

Os folhelhos pretos devonianos da Formação Barreirinha caracterizamse pela alta radioatividade na porção basal, grande extensão areal, espessura e profundidade de soterramento variável que vão de exposição na superfície até mais de 3000 m. Eles são as principais rochas geradoras do sistema petrolífero convencional da Bacia do Amazonas, e recentemente foram consideradas como promissores plays de gás não convencional. Folhelhos são geralmente caracterizados por uma matriz fechada, que faz com que sejam relativamente impermeáveis em relação ao fluxo de gás, a menos que ocorram fraturas, e dependendo das suas características geológicas e geoquímicas podem funcionar com um Sistema Petrolífero autossuficiente, atuando tanto como rocha fonte, quanto como reservatório de gás (reservatório Shale Gas). Assim, o gás natural termogênico ou biogênico gerado pode ser armazenado em folhelhos ricos em matéria orgânica na forma livre, adsorvida, ou em estado dissolvido. Em contraste com os sistemas petrolíferos convencionais, reservatórios Shale Gas, possuem mecanismos de aprisionamento e armazenamento únicos, sendo necessária a utilização de técnicas de avaliações específicas. No entanto, folhelhos prolíficos geralmente podem ser reconhecidos a partir de alguns parâmetros básicos: arquitetura geológica e sedimentar, propriedades geoquímicas e petrofísicas e composição mineralógica. Tendo em vista a carência de pesquisas de caráter descritivo, com cunho exploratório dos folhelhos geradores da Formação Barreirinha, esta dissertação tem como objetivo introduzir uma metodologia de identificação de intervalos de folhelho gerador com potencial para reservatório Shale Gas. Começando com uma investigação regional sobre o contexto geológico e sedimentar, seguido de uma avaliação abrangente enfocando as características geoquímicas, petrofísicas e litofácies dos folhelhos a partir da integração de parâmetros obtidos de perfis geofísicos de poço, análises geoquímicas e aplicação dos conceitos de Estratigrafia de Sequencia. / The Devonian black shale of Barreirinha formation is characterized by high radioactivity in the basal portion, large areal extension, thickness and depth of burial variable which ranges from exposure to surface to depth greater than 3000 m. This formation contains the main source rocks of conventional petroleum system of the Amazonas Basin, and recently were considered promising unconventional gas plays. Shales are generally characterized by a closed die, which makes them relatively impervious for gas flow unless fracturing occur, and depending on their geological and geochemical characteristics they might behave as a selfcontained Petroleum System, acting as both source rock and as a gas reservoir (Shale gas reservoir). Thus, the thermogenic or biogenic gas generated can be stored in shale rich in organic matter in free form, adsorbed or dissolved state. In contrast to conventional petroleum systems, Shale Gas reservoirs, have trapping mechanisms and unique storage, requiring the use of specific assessment techniques. However, prolific shale can usually be recognized based on some basic parameters: geological and sedimentary architecture, geochemical and petrophysical properties and mineralogical composition. Given the lack of descriptive research, about the exploration potential of the Barreirinha formations shale, this dissertation aims to introduce a methodology of identification of intervals that could be potential shale gas reservoirs. Starting with a regional research about the geological and sedimentary context, followed by a comprehensive review focusing on the geochemical characteristics, petrophysical and lithofacies based on the integration of the parameters obtained by well log, geochemical analysis and application of Sequence Stratigraphy concepts.

A seqüência mesozóica da bacia de Ucayali é a maior produtora de gás e condensado do Peru. A área do trabalho, denominada Grande Camisea, fica na parte sul da bacia e, na atualidade, pertence à companhia Plupetrol Peru Corporation. Neste trabalho, foi aplicado um método de interpretação de perfis de indução em um poço petrolífero no sector San Martin do campo Camisea (QuickLook Interpretation method). O objetivo consiste na caracterização do reservatório de San Martín utilizando um método de interpretação rápida de perfis elétricos e, assim, fornecer uma visão geral no entendimento de parâmetros de poços e reservatórios, de zonas produtivas e suas características petrofísicas de porosidade e de saturação do óleo. Para validar a interpretação, foram utilizadas a descrição geológica de testemunhos e amostras de calha, descrição e informação do sistema petrolífero do campo e a geologia regional da zona de interesse da bacia. Desta forma, foi possível apresentar uma comparação entre os valores obtidos através dos métodos detalhados executados pela Pluspetrol e o método rápido de interpretação aplicado aqui, assim como o desvio entre ambos os resultados. / The Mesozoic sequence of the Ucayali basin is the main producer of gas and condensate of Peru. The work area is called Gran Camisea, located in the south part of the basin, and, in the present time, belongs to the company Plupetrol Peru Corporation. In this work, a well log interpretation method was used in a gas well in San Martin area, part of the Camisea field. The goal is the characterization of the reservoir of San Martín using a Quick Look log interpretation method, and thus to supply a general view in the understanding of well and reservoirs parameters, productive zones and its petrophysics characteristics of porosity and saturation. To validate the interpretation, besides using the geologic description of well cores and cutting sampling, it was used the description and information of the petroleum system of Camisea gas field and its regional geology. It was possible to present a comparison between Pluspetrol values, obtained through detailed methods, and those from the Quick Look log interpretation method used here, as well as an analysis of convergence between both results.

O periódico eletrônico ganha cada vez mais credibilidade no campo da informação científica, e muitas são as iniciativas para a criação de novos periódicos. Contudo, apesar desse crescimento em número, são poucos os estudos que abordam a busca e o uso de informação realizados nas versões eletrônicas destes produtos, assim como o internauta que os acessa. A análise de logs é um método que objetiva identificar as ações dos usuários de um site através da investigação dos arquivos de logs do servidor web. Esse tipo de análise pode auxiliar no levantamento de informações sobre a utilização de um periódico eletrônico, mas poucas foram as pesquisas brasileiras que adotaram este método. Dessa forma, torna-se necessário também avaliar esse método aplicado ao estudo de periódicos. O foco da pesquisa é analisar o comportamento de busca e uso da informação em periódicos científicos eletrônicos por meio da análise de logs da revista Psicologia: reflexão e crítica. Esse trabalho objetiva também levantar as diferentes formas de acesso ao periódico, verificar o número de acessos e sua distribuição pelo território nacional, verificar a freqüência de uso do periódico, verificar os tipos de internauta a visitar o periódico, levantar os padrões de comportamento de busca e uso possíveis. As bases teóricas para essa pesquisa são os conceitos de comportamento de busca e uso da informação, periódico científico eletrônico e visibilidade. A metodologia utilizada é a análise de logs fornecidos pela Scientific Electronic Library Online (SciELO), para a obtenção de dados quantitativos, e entrevistas, para a obtenção de dados qualitativos. Por meio da metodologia aplicada chegou-se a um panorama geral da busca e uso do periódico, onde foram determinadas a freqüência de visitação, quem utiliza, quais suas ações no periódico e a origem desses internautas. Constatou-se também a existência de oito padrões de comportamento informacional, que são as seqüências de ações com maior probabilidade de serem realizadas pelos usuários do periódico. / The electronic journals are increasingly gaining more credibility in the information science field, and there are many initiatives for the creation of new journals. However, despite this growth in quantity, there are only a few studies on the information search and use performed in the electronic version of these products, as well as the user who access them. The log analysis is a method which aims to identify the actions of the users of a site through the investigation of the web server’s log files. This type of analysis can help in obtaining information regarding the use of an electronic journal, but there are only a few Brazilian studies which adopted this method. Hence, it is also necessary to evaluate this methodology applied to the journals study. The focus of this research is to analyze the information search and use behavior in scientific electronic journals through the logs analysis of the journal Psicologia: reflexão e crítica. This work also aims to identify the different forms of accessing the journal, to verify the access number and its distribution in the national territory, to verify the frequency of use of the journal, to verify the types of users that visit the journal, and to identify the patterns of the possible information search and use behavior. The theoretic basis for this research are the concepts of information search and use behavior, scientific electronic journal and visibility. The used methodology is the analysis of the logs provided by the Scientific Electronic Library Online (SciELO), for gathering the quantitative data, and interviews, for gathering the qualitative data. Through the applied methodology we have reached a general view of information search and use behavior in the journal, and in this occasion it was determined the visiting frequency, who uses it, what were his/her actions in the journal and the origin of there users. It was also identified the existence of eight patterns of informational behavior, which are the sequences of actions with the biggest probability of being performed by the users of the journal.

Made available in DSpace on 2014-06-11T19:24:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-14Bitstream added on 2014-06-13T20:52:20Z : No. of bitstreams: 1 coneglian_a_me_botfca.pdf: 1568717 bytes, checksum: b555fef630db17c6e5cf9fb9b9c28035 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O presente estudo teve como objetivo determinar um modelo matematico para estimar o tempo de aquecimento de toras de Eucalyptus grandis em vapor e agua quente e a implicacao dos tratamentos termicos sobre a qualidade e rendimento na producao de laminas. Para tanto, foram utilizadas toras com diametros de 25 . 30 cm, 30 . 35 cm, 35 . 40 cm, procedentes do Horto Florestal de Aguas de Santa Barbara-SP. Estas toras foram submetidas a dois (2) tipos de tratamento termico a uma temperatura de 85o C, sendo que no primeiro as toras foram vaporizadas e no segundo as toras foram aquecidas em agua quente. Em ambos os tratamentos termicos a madeira foi aquecida ate que o rolo-resto (50mm) atingisse 80o C. Para o monitoramento da temperatura e tempo de aquecimento, foi inserido um termopar no roloresto, os dados foram coletados por um equipamento datalogger CR10, minuto a minuto ate que atingisse a temperatura desejada. Apos o periodo de aquecimento, as toras foram laminadas em um torno laminador, guilhotinadas, numeradas e separadas, para avaliar o efeito dos tratamentos termicos sobre a qualidade das laminas em diferentes classes de diametros. Cada lamina foi medida na direcao tangencial e radial antes da secagem ao ar livre e posteriormente a mesma. Isso ocorreu tanto com as laminas provenientes das toras do tratamento termico com agua quente como das toras vaporizadas. O modelo matematico logistico inverso obtido para estimar o tempo de aquecimento das toras tanto em agua quente quanto para vapor, levando em consideracao as tres classes de diametro e a profundidade do rolo-resto... / The aim of this study was to determine a mathematical model to estimate the heating time for Eucalyptus grandis logs, in vapor and thermal hot water and the implication of thermal treatments on the sheet production quality and yield. In order to do so, logs with a diameter of 25 . 30 cm, 30 . 35 cm e 35 . 40 were used, coming from Horto Florestal, Aguas de Santa Barbara, Sao Paulo. The logs were submitted to two (2) types of thermal treatment at a temperature of 85 o C. In the first treatment, the logs were vaporized and in the second one they were heated in hot water. In both thermal treatments, the wood was heated until the rollrest reached 80 oC. For the temperature and heating time monitoring a thermo pair was filled in the roll-rest. A CR10 equipment datalogger was used for collecting the data every minute until the desired temperature was reached. After the heating period, the logs were laminated by the laminating lathe, guillotined, numbered and separated, to evaluate the effect of the thermal treatments on the sheet quality in different diameter classes. Each sheet was measured in the tangential and radial directions before the outdoors drying and then to the same. The same thing happened both for the sheets coming from the hot water thermal treatment logs as for the vaporized logs. The converse mathematical logistic model obtained to estimate the heating time of the logs, in hot water and vapor, considering the three diameter classes and the roll-rest depth with 50mm radius, was the following one... (Complete abstract, click electronic access below)