Aplicação de agentes remineralizantes sobre o esmalte clareado: eficácia contra o manchamento por café

The aim of this study was to evaluate the influence of remineralizing agents on the susceptibility of enamel cleared by the coffee pigmentation during office bleaching. Fifty bovine incisors were selected and randomly assigned into 5 groups (n = 10) on the basis of remineralizing agents: G1 gel hydrogen peroxide to 35% (control group); G2, hydrogen peroxide gel and a 35% gel 2% neutral fluorine; G3, hydrogen peroxide gel and a 35% nanostructured calcium phosphate gel, G4, hydrogen peroxide gel and a 35% casein fosfoptídia-phosphate and amorphous calcium folder; G5 hydrogen peroxide gel to 35% without mineralizing agent. All groups exception G1 (control group) were subjected to pigmentation soluble coffee according to the manufacturer's guidelines. The samples were immersed in coffee at temperature of 55° C, 1 time a day for 4 minutes. Color changes were performed by Easyshade spectrophotometer at CIE Lab method before and after 3 whitening sessions. Data were analyzed by analysis of variance ANOVA. The results showed statistically significant differences between the remineralizing substances for the parameters L *, a *, b * ΔE (p <0.0001). The L * values for the group G5, and the b * for G2 and G5 groups differed from the control group. After the 3rd whitening session, Fluor's group (G2) and that without mineralizing agent (G5) showed ΔE values less than the control group that did not undergo pigmentation. It was concluded that only the nanoclusters remineralizing agents Phosphopeptides Casein-Amorphous Calcium Phosphate and Calcium Amorphous phosphate were able to reduce the coffee interference whitening efficacy of hydrogen peroxide.

Avaliação da atividade antimicrobiana das defensinas recombinantes de ervilha (drr230a) e café (cd1) produzidas em Pichia pastoris

The inefficiency of chemical pesticides to control phytopathogenic fungi in agriculture and the frequent incidence of human diseases caused by bacteria which are resistant to antibiotics lead to the search for alternative antimicrobial compounds. In this context, plant defensins are a promising tool for the control of both plant and human pathogenic agents. Plant defensins are cationic peptides of about 50 amino acid residues, rich in cysteine and whose tridimensional structure is considerably conserved among different plant species. These antimicrobial molecules represent an important innate component from plant defense response against pathogens and are expressed in various plant tissues, such as leaves, tubers, flowers, pods and seeds. The present work aimed at the evaluation of the antimicrobial activity of two plant defensins against different phytopathogenic fungi and pathogenic bacteria to humans. The defensin Drr230a, whose gene was isolated from pea (Pisum sativum), and the defensin CD1,whose gene was identified within coffee (Coffea arabica) transcriptome, were subcloned in yeast expression vector and expressed in Pichia pastoris. The gene cd1 was subcloned as two different recombinant forms: CD1tC, containing a six-histidine sequence (6xHis) at the peptide C-terminal region and CD1tN, containing 6xHis coding sequence at the N-terminal region. In the case of the defensin Drr230a, the 6xHis coding sequence was inserted only at the N-terminal region. Assays of the antimicrobial activity of the purified recombinant proteins rDrr230a and rCD1 against Phakopsora pachyrhizi, causal agent of soybean Asian rust, were performed to analyze the in vitro spore germination inhibition and disease severity caused by the fungus in planta. Both recombinant defensins were able to inhibit P. pachyrhizi uredospore germination, with no difference between the antimicrobial action of either CD1tC or CD1tN. Moreover, rDrr230a and rCD1 drastically reduced severity of soybean Asian rust, as demonstrated by in planta assays. In spite of the fact that rCD1 was not able to inhibit proliferation of the human pathogenic bacteria Staplylococcus aureus and Klebsiella pneumoniae, rCD1 was able to inhibit growth of the phytopathogenic fungus Fusarium tucumaniae, that causes soybean sudden death syndrome. The obtained results show that these plant defensins are useful candidates to be used in plant genetic engineering programs to control agriculture impacting fungal diseases.

Uso de correntropia na generalização de funções cicloestacionárias e aplicações para a extração de características de sinais modulados

Information extraction is a frequent and relevant problem in digital signal processing. In the past few years, different methods have been utilized for the parameterization of signals and the achievement of efficient descriptors. When the signals possess statistical cyclostationary properties, the Cyclic Autocorrelation Function (CAF) and the Spectral Cyclic Density (SCD) can be used to extract second-order cyclostationary information. However, second-order cyclostationary information is poor in nongaussian signals, as the cyclostationary analysis in this case should comprise higher-order statistical information. This paper proposes a new mathematical tool for the higher-order cyclostationary analysis based on the correntropy function. Specifically, the cyclostationary analysis is revisited focusing on the information theory, while the Cyclic Correntropy Function (CCF) and Cyclic Correntropy Spectral Density (CCSD) are also defined. Besides, it is analytically proven that the CCF contains information regarding second- and higher-order cyclostationary moments, being a generalization of the CAF. The performance of the aforementioned new functions in the extraction of higher-order cyclostationary characteristics is analyzed in a wireless communication system where nongaussian noise exists.

Influência da pressão e da vazão de concentrado sobre o desempenho de ultrafiltração no pós-tratamento de esgotos

Despite the numerous advantages resulting from the use of membrane filters technology, intrinsic limitations fouling process become relevant to its applicability. The control of operating conditions is an important tool to mitigate fouling and achieve good levels of efficiency. In this sense, the objective of this study was to investigate the effect of transmembrane pressure and concentrate flow in the performance of ultrafiltration, applied to the post-treatment of domestic sewage. The process was evaluated and optimized by varying the pressure (0.5 and 1.5 bar) and the concentrate flow (300 and 600 L/h), using a 22 factorial design, in order to investigate the effects on the permeate flow and quality of effluents generated at each operating condition. We evaluated the following quality indicators for permeate: pH, electrical conductivity, total suspended solids, turbidity, calcium and Chemical Oxygen Demand (COD). In all tests, we observed marked reduction in the permeate flux at the early stages, followed by a slow decline that lasted until it reaches a relatively constant level, around 120 minutes of filtration. The increased pressure resulted in a higher initial permeate flux, but the decrease of the flow with time is greater for tests at higher pressure, indicating a more pronounced fouling process. On the other hand, increasing the concentrate flow resulted in a slower decline in permeate flux with the filtration time. Regarding the quality of permeate, the transmembrane pressure of 0,5 bar was the one that allowed better results, and was statistically confirmed through the two-way ANOVA test with repeated measures, significant effect of pressure on the turbidity of the permeate. The concentrate flow, in turn, showed no significant influence on any of the quality parameters. Thus, we conclude that, from an economic and environmental point of view, it is more interesting to operate ultrafiltration membrane system with a lower concentrate flow associated with a low transmembrane pressure, since under these conditions will produce less waste, and the permeate will present lower concentrations of the analyzed constituent, especially lower turbidity.

Análise do uso do Portal de Periódicos da CAPES na perspectiva de mestres e doutores formados pelo Programa de Pós-graduação em Administração da UFRN

The Brazilian CAPES Journal Portal aims to provide Information in Science and Technology (IST) for academic users. Thus, it is considered a relevant instrument for post-graduation dynamics and the country´s Science and Technology (S&T) development. Despite its importance, there are still few studies that focus on the policy analysis and efficiency of these resources. This research aims to fill in this gap once it proposes an analysis of the use of the CAPES Journal Portal done on behalf of the master´s and doctoral alumni of the Post Graduate Program in Management (PPGA) at the Federal University of Rio Grande do Norte (UFRN). The operationalization of the research´s main objective was possible through the specific objectives: characterize graduate profile as CAPES Journal Portal users b) identify motivation for the use of CAPES Journal Portal c) detect graduate satisfaction degree in information seeking done at CAPES Journal Portal d) verify graduate satisfaction regarding the use of the CAPES Journal Portal e) verify the use of the information that is obtained by graduates in the development of their academic activities. The research is of descriptive nature employing a mixed methodological strategy in which quantitative approach predominates. Data collection was done through a web survey questionnaire. Quantitative data analysis was made possible through the use of a statistical method. As for qualitative analysis, there was use of the Brenda Dervin´s sense-making approach as well as content analysis in open ended questions. The research samples were composed by 90 graduate students who had defended their dissertation/thesis in the PPGA program at UFRN in the time span of 2010-2013. This represented by 88% of this population. As for user profile, the analysis has made evident that there are no quantitative differences related to gender. There is predominance of male graduates that were aged 26 to 30 years old. As for female graduates, the great majority were 31 o 35 years old. Most graduates had Master´s degree scholarship in order to support their study. It was also seen that the great majority claim to use the Portal during their post graduation studies. The main reasons responsible for non use was: preference for the use of other data bases and lack of knowledge regarding the Portal. It was observed that the most used information resources were theses and dissertations. Data also indicate preference for complete text. Those who have used the Portal also claimed to have used other electronic information fonts in order to fulfill their information needs. The information fonts that were researched outside in the Portal were monographs, dissertations and thesis. Scielo was the most used information font. Results reveal that access and use of the Portal has been done in a regular manner during post graduation studies. But on the other hand, graduates also make use of other electronic information fonts in order to meet their information needs. The study also confirmed the important mission performed by the Portal regarding Brazilian scientific communication production. This was seen even though users have reported the need for improvement in some aspects such as: periodic training in order to promote, encourage and teach more effective use of the portal; investment aiming the expansion of Social Sciences Collection in the Portal as well as the need to implement continuous evaluation process related to user satisfaction in regarding the services provided.

"Ombro a ombro com os mais fracos": a inserção de João Café Filho nos espaços do trabalhador na cidade do Natal 1922 - 1937

The purpose of this thesis is to analyze how João Café Filho constituted a discourse of advocate of the labor movement and workers in different sociability spaces. It is intended to understand, on one hand, how political relations were established between different categories of workers and the ‘middle classes’ and, on the other hand, how places were instituted to house the meeting of these relations. It a ims to understand the insertion of Café Filho in union activities in the urban world. It demonstrates specificities of the political culture in Natal emphasizing the dispute between a city politically ruled by a still reigning rural paternalistic mentality and the rise of a new way to experience the urban conflicts which appeared. Temporally, the work is delimited between 1922 (proclaimed by Café Filho himself as the initial period of his political action) and 1937 (when he broke up with Vargas and went into exile in Argentina). The research was constituted by three main document types: several published newspapers between the decades of 1920 and 1930 in the cities of Natal, Recife, São Paulo, Porto Alegre and Rio de Janeiro; the autobiographical memoirs written by Café Filho himself and memoirs of other people who lived in his time. The main pillars that have supported the work were: the concepts of society and individuals (ELIAS, 1994; 1995), political cultures (BERSTEIN, 1998) and theater of the memory (GOMES, 2004); the sociability spaces category (CERTEAU, 1994; MALATIAN, 2001; RIOX, 1996); the biography notion (DOSSE, 2009; LORIGA, 2011). We demonstrated that Café Filho acted in some sociability spaces as: the Jornal do Norte, the Federação Regional do Trabalho and the Partido Democrático Nacional. In such spaces, Café Filho, gradually, become an important leader of workers and, at the same time, linked to national entities led to the opposition that fight against the power established in the Brazilian First Republic. In Café Filho’s interpretation, workers were individuals who needed to fight against the political structures prevailing at that time because the poor living conditions and the low representativeness of this group were caused by the way the political system in the First Republic was structured. After the 1930 Movement, the 3 de Outubro Club, the Jornal and the Labor Federation of Natal were constituted in spaces where the cafeista critical discourse about the government was changed: workers should follow the official syndicalism and defend the 1930 Movement which put Vargas in the presidency of the Republic.

Degradação de paracetamol empregando tecnologia oxidativa avançada baseada em fotocatálise heterogênea usando irradiação artificial e solar

In this work, the oxidation and mineralization of paracetamol, based in an advanced oxidative process promoted by heterogeneous photocatalysis, was evaluated. The action of two photocatalysts (titanium dioxide, and a composite based on the association between titanium dioxide and zinc phthalocyanine dye) was studied. First of all, experiments in laboratory scale were performed using as radiation font a 400 W high pressure mercury lamp. The mineralization of paracetamol, promoted by both photocatalysts, was evaluated working with 4L of solution containing 10 mg L-1 of paracetamol and 100 mg L-1 of photocatalyst. To find the best experimental conditions, the influence of hydrogen peroxide concentration and pH was evaluated for the reactions. The best results for the reactions in laboratory scale was obtained using 33,00 mg L-1 of hydrogen peroxide in natural pH (6,80). Under these conditions, 100% oxidation was reached in just 40 minutes of reaction using TiO2 P25, while the mineralization was 78%. Using the composite, the mineralization was 63% in 2 hours of reaction and a oxidation of almost 100% was reached after 60 minutes. A CPC reactor (compound parabolic concentrator) was employed in the expanded work scale, using the sun as irradiation source. In this case the experiments were performed using 50 L of aqueous solution containing 10 mg L-1 of paracetamol and 100 mg L-1 of photocatalyst. The assays were done at pH 3,00 and natural pH (6,80). The used concentration of hydrogen peroxide was 33,00 mg L-1, adopted after laboratory scale studies. The reaction at pH 3,00 shows to be more advantageous, since under natural pH (6,80), the use of deionized water was necessary to prepare the solutions, probably because the deleterious action of carbonate ions, known hydroxyl radical scavengers. Using solar irradiation, the reaction mediated by the composite was more efficient when compared with the assays under laboratory scale since the composite presents the advantage of promoting a better use of visible radiation. Under these conditions, the mineralization increased from 40% to 56% under pH 3,00. At natural pH the oxidation occurred more slowly and the mineralization decreased from 56% to 50%. Thus, the use of pH 3,00 will be more interesting in real scale applications, even if it is necessary the pH correction before the discard of the treated effluent to the environment.

Empreendedorismo tecnológico como opção da segunda carreira: pós-aposentadoria

Institutos de Ciência e Tecnologia são organizações que constroem grandes acervos de conhecimento de ponta, combinando conhecimento explicito e tácito decorrente da formação do pesquisador. Há potencial para que o empregado, em fase de aposentadoria, defina um novo curso de carreira, com foco na aplicação dos saberes de alto valor agregado. Este artigo se insere nesta categoria, descrevendo as estratégias oriundas dessas Instituições como uma oportunidade do empreendedorismo como opção de segunda carreira para os empregados que estão se aposentando e saindo da Instituição. Trata-se de uma pesquisa de natureza quantitativa, do tipo exploratório. Com o intuito de contribuir na política de recursos humanos, estimulando os programas de intraempreendedorismo e preparando os empregados para o empreendedorismo como uma opção de segunda carreira, uma das estratégias corporativa das instituições de pesquisa aplicada à transferência de tecnologia.

Experiências de Combate e a sua Relação com a Sintomatologia Associada à Perturbação Pós-Stress Traumático em Veteranos da Guerra Colonial Portuguesa

Objectivos: O presente estudo avaliou a relação entre diversos aspectos objectivos e subjectivos inerentes às experiências de combate/guerra e sintomatologia associada à Perturbação Pós-Stress Traumático. Os instrumentos de auto-resposta utilizados na colheita dos dados foram analisados quanto às suas principais propriedades psicométricas. Métodos: A amostra foi composta por 105 combatentes da Guerra Colonial Portuguesa. Foram utilizados os seguintes instrumentos de avaliação: um questionário sóciodemográfico de auto-resposta para a caracterização da amostra, o Posttraumatic Stress Disorder Checklist (para militares), o Peritraumatic Dissociative Experiences Questionnaire, o Questionário de Experiências de Combate e duas escalas do Deployment Risk and Resilience Inventory, nomeadamente a Difficult Livings and Working Environment Scale e a Perceived Threat Scale. Resultados: O estudo das qualidades psicométricas dos instrumentos apresenta uma consistência interna superior a .86 e uma estabilidade temporal superior a .79. A análise factorial do Peritraumatic Dissociative Experiences Questionnaire apresenta bons valores na medida de Kaiser-Meyer-Olkin e no teste de esfericidade de Bartlett. Na rotação de Varimax é extraído um factor, predizendo a sua unidimensionalidade, que explica cerca de 70% da variância total do questionário. Os resultados relativos à validade divergentediscriminante indicam, por si só, que esta se apresenta de forma clara entre os instrumentos estudados (PCL-M, PDEQ, DLWES e PTS) no subgrupo com PTSD, com excepção da verificada entre o PCL-M e o PDEQ.. Quanto à validade de critério, constatam-se diferenças entre os subgrupos com e sem PTSD. Através do método da regressão linear múltipla, duas das seis variáveis têm, isoladamente, um peso preditivo significativo para a PTSD, nomeadamente a frequência de exposição a situações típicas e objectivas de combate/ guerra e os desconfortos diários durante a(s) comissão(ões). Ao considerarmos as variáveis no seu conjunto, aquelas que mais contribuem são a dissociação peritraumática e os desconfortos diários durante a(s) comissão(ões). Conclusão: Constata-se que os factores peritraumáticos em estudo desempenham um importante papel no desenvolvimento da sintomatologia inerente à PTSD. /

Construção das capacidades organizacionais de tecnologia da informação no contexto dos sistemas institucionais integrados de gestão da UFRN

The IT capability is a organizational ability to perform activities of this role more effectively and an important mechanism in creating value. Its building process (stages of creation and development) occurs through management initiatives for improvement in the performance of their activities, using human resources and IT assets complementary responsible for the evolution of their organizational routines. This research deals with the IT capabilities related to SIG (integrated institutional management systems), built and deployed in UFRN (Universidade Federal do Rio Grande do Norte) to realization and control of administrative, academic and human resources activities. Since 2009, through cooperative agreements with federal and educational institutions of direct administration, UFRN has supported the implementation of these systems, currently involving more than 30 institutions. The present study aims to understand how IT capabilities, relevant in the design, implementation and dissemination of SIG, were built over time. This is a single case study of qualitative and longitudinal nature, performed by capturing, coding and analysis from secondary data and from semi-structured interviews conducted primarily with members of Superintenência de Informática, organizational unit responsible for SIG systems in UFRN. As a result, the technical, of internal relationship and external cooperation capabilities were identified as relevant in the successful trajectory of SIG systems, which have evolved in different ways. The technical capacity, initiated in 2004, toured the stages of creation and development until it reached the stage of stability in 2013, due to technological limits. Regarding the internal relationship capability, begun in 2006, it toured the stages of creation and development, having extended its scope of activities in 2009, being in development since then. Unlike the standard life cycle observed in the literature, the external cooperation capability was initiated by an intensity of initiatives and developments in the routines in 2009, which were decreasing to cease in 2013 in order to stabilize the technological infrastructure already created for cooperative institutions. It was still identified the start of cooperation in 2009 as an important event selection, responsible for changing or creating trajectories of evolution in all three capacities. The most frequent improvements initiatives were of organizational nature and the internal planning activity has been transformed over the routines of the three capabilities. Important resources and complementary assets have been identified as important for the realization of initiatives, such as human resources technical knowledge to the technical capabilities and external cooperation, and business knowledge, for all of them, as well as IT assets: the iproject application for control of development processes, and the document repository wiki. All these resources and complementary assets grew along the capacities, demonstrating its strategic value to SINFO/UFRN

A influência do processo de terceirização de tecnologia da informação na utilização dos modelos de contratação de serviços: um estudo de casos múltiplos

The change in the economic world and the emergence of Internet as a tool for communication and integration among the markets have forced organizations to adopt a different structure, process-oriented with a focus on information management. Thus, information technology has gained prominence in the organizational context, increasing its complexity and range of services provided by this function. Moreover, outsourcing has become an important model for flexible corporate structure, helping organizations to achieve better results when carrying out their activities and processes and be more competitive. To make the IT outsourcing, it is necessary to follow certain steps that range from strategic assessment to the management of outsourced service. Such steps can influence the form of contracting services, varying the types of service providers and contractors. Thus, the study aimed to identify how this IT outsourcing process influences the use of models for contracting services. For this, a study was conducted in multiple cases study involving two companies in Rio Grande do Norte State, specifically the health sector. Data collection was carried out with the CIOs of the companies surveyed through semi-structured interviews. According to the results obtained, it was found that the outsourcing process more structured influences the use of a more advanced contracting model. However, there are features found in these steps carrying more clearly this influence, as the goals pursued by outsourcing, the criteria used in selecting the supplier, a contract negotiation, how to transition services and the use of methods management, but can vary depending on the level of maturity in the relationship of the companies examined. Moreover, it was found that the use of contracting model may also influence how it is developed the IT outsourcing process, requiring or not its more formalized and organization

Aspectos do gerenciamento de riscos de tecnologia da informação nas empresas: um estudo de caso múltiplos

The information technology - IT- benefits have been more perceived during the last decades. Both IT and business managers are dealing with subjects like governance, IT-Business alignment, information security and others on their top priorities. Talking about governance, specifically, managers are facing it with a technical approach, that gives emphasis on protection against invasions, antivirus systems, access controls and others technical issues. The IT risk management, commonly, is faced under this approach, that means, has its importance reduced and delegated to IT Departments. On the last two decades, a new IT risk management perspective raised, bringing an holistic view of IT risk to the organization. According to this new perspective, the strategies formulation process should take into account the IT risks. With the growing of IT dependence on most of organizations, the necessity of a better comprehension about the subject becomes more clear. This work shows a study in three public organizations of the Pernambuco State that investigates how those organizations manage their IT risks. Structured interviews were made with IT managers, and later, analyzed and compared with conceptual categories found in the literature. The results shows that the IT risks culture and IT governance are weakly understood and implemented on those organizations, where there are not such an IT risk methodology formally defined, neither executed. In addition, most of practices suggested in the literature were found, even without an alignment with an IT risks management process

Práticas de governança de tecnologia da informação: um estudo de caso em empresas de telecomunicações do Rio Grande do Norte

This study aims to understand the general model of governance of information technology adopted by telecommunication companies operating in Rio Grande do Norte. The research methodology used involved a theoretical and empirical approach prepared, involving two case studies on companies in the telecommunications industry working in the state of Rio Grande do Norte. The study covered the area of IT organizations, through interviews with managers responsible for the area of Telecommunications / IT. To study in accordance with the approach and address the problem of research, this study was based on qualitative criteria, which enabled the understanding of how companies adopt the governance of information technology. In conclusion, it was found that the governance practices of information technology employees are incipient, but that meet the needs of business and that they intend to implement in specific areas and use other practices of IT governance

Coevolução e as práticas isomórficas de gestão: um estudo sobre os processos de mudanças institucionais no Instituto Federal de Educação, Ciência e Tecnologia do RN

The Federal Institution for Education, Science and Technology, in its historical path, has been living different changes. The transformations occurred along the way have been determined by coercive forces from the institutional environment, which has became more and more broad and complex throughout the time, obtaining diverse characteristics and new elements such as non institutional factors1 which started to contribute with the other changes. In this context, this work aims to study the isomorphic practices of the managers in the institutional changes process of the IFRN in 1998 and 2008, as of a theoretical coevolutionary perspective (CHILD; RODRIGUES; LEWIN; CARROL; VOLBERDA, 2003). This theory brings a new point of view for the organization analysis to the organizational studies, since it offers a non deterministic and non linear lection of the evolution process, which means, a coevolution. Thus, the organizations and their institutional and non institutional environment auto evolve, auto organize and auto reproduce. Therefore, the institutional and non institutional factors of the macro environment keep a continuous interdependence relationship with the organizations. For the means of this study, it is important to understand that is impossible to comprehend the object, the isomorphic practices, without considering that the previous institutional changes and its evolutions, its continuations and discontinuations, important in the coevolution process. As such, to call upon the institutional historical track is a fundamental aspect to materialize this study, for the recursive movement is indeed present in the coevolution. Another important point to make this research effective is that it is not possible to abdicate from the hologramatic view2 of this study, which considers the object, the isomorphic practices, part of the whole and this whole is also in the parts, therefore it is impossible to comprehend the object of study outside the context where it belongs. With this, as of the objective previously proposed, it is necessary to describe the characteristics of coevolution of the institutional changes related in 1998 and 2008; analyze the dynamic of the isomorphic mechanisms in its respective institutional change process; and describe the lessons learned which the isomorphic practices left to the IFRN, regarding its benefits and difficulties. All these transformations happened through coercive forces3 of the institutional environment. As of the Nineties, these forces became stronger, the environment became broader and more complex, with the emergency of new environmental factors. This study proposed to study the managing process and its practices, related to the micro environment, although it is required to articulate these actions, the demands and requirements from the macro environment. To make this research effective, semi structured interviews have been conducted with the managers who participated in both institutional change processes. In the results analysis, it has been possible to verify the particularity of each change, the one from 1998 with a strong normative action of the managers against coercive forces from the government for the search of recognition and the institutional legitimation and the one in 2008, which has been characterized by the normative action by managers in agreement with the coercive forces from the government, in favor of the government policy for the technological professional education. However, the results analysis it is possible to notice the evidence of a belonging feeling from the interviewed managers

Fatores que influenciam a intenção de compra online: aplicação de um modelo adaptado de aceitação da tecnologia para o comércio eletrônico

This research aims to understand the factors that influence intention to online purchase of consumers, and to identify between these factors those that influence the users and the nonusers of electronic commerce. Thus, it is an applied, exploratory and descriptive research, developed in a quantitative model. Data collection was done through a questionnaire administered to a sample of 194 graduate students from the Centre for Applied Social Sciences of UFRN and data analysis was performed using descriptive statistics, confirmatory factorial analysis and simple and multiple linear regression analysis. The results of descriptive statistics revealed that respondents in general and users of electronic commerce have positive perceptions of ease of use, usefulness and social influence about buying online, and intend to make purchases on Internet over the next six months. As for the non-users of electronic commerce, they do not trust the Internet to transact business, have negative perceptions of risk and social influence over purchasing online, and does not intend to make purchases on Internet over the next six months. Through confirmatory factorial analysis six factors were set up: behavioral intention, perceived ease of use, perceived usefulness, perceived risk, trust and social influence. Through multiple regression analysis, was observed that all these factors influence online purchase intentions of respondents in general, that only the social influence does not influence the intention to continue buying on the Internet from users of electronic commerce, and that only trust and social influence affect the intention to purchase online from non-users of electronic commerce. Through simple regression analysis, was found that trust influences perceptions of ease of use, usefulness and risk of respondents in general and users of electronic commerce, and that trust does not influence the perceptions of risk of non-users of electronic commerce. Finally, it was also found that the perceived ease of use influences perceived usefulness of the three groups. Given this scenario, it was concluded that it is extremely important that organizations that work with online sales know the factors that influence consumers purchasing intentions in order to gain space in their market