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Reactions to decisions are shaped by both outcome and procedural fairness. Moreover, outcome and procedural fairness interact to influence beliefs and behaviors. However, different types of “process/outcome” interaction effects have emerged. Many studies have shown that people react particularly negatively when they receive unfair or unfavorable outcomes accompanied by unfair procedures (the “low-low” interactive pattern). However, others find that people react especially positively when they receive fair or favorable outcomes accompanied by fair procedures (the “high-high” interactive pattern). We propose that trust in decision-making authorities dictates the form of the process/outcome interaction. Across three studies, when trust was high, the “low-low” interactive pattern emerged. When trust was low, the “high-high” interactive pattern emerged. The findings suggest that when people’s experience of outcome and procedural fairness diverged from how they expected to be treated, they reacted in the direction of their experiences; otherwise, their reactions were consistent with their expectations.

Recent research has shown that ethical behavior can be influenced by features of the immediate environment such as the presence of a cheater or the characteristics of a room. We suggest ethical behavior is similarly shaped by a more diffuse and enduring situational feature: the state of the economy. Building on work showing that prosperity fuels overconfidence, risk-taking, and greed, we argue that ethical behavior improves when the economy falters. Five studies spanning diverse populations and different types of misconduct find support for this hypothesis. During prosperous economic times, companies were more likely to submit regulatory filings that would later be restated for fraud (Study 1), academics were more likely to publish papers that later would be retracted (Study 2), Major League Baseball pitchers were more likely to try to harm opposing batters (Study 3), and students were more likely to steal, damage property, shoplift, and submit plagiarized work (Studies 4 and 5). While a large body of research has shown that proximal situational variables can influence ethical impulses, our findings suggest that more diffuse macroeconomic factors can similarly shape unethical behavior.

here has been a great advance in the grinding process by the development of dressing, lubri-refrigeration and other methods. Nevertheless, all of these advances were gained only for continuous cutting; in other words, the ground workpiece profile remains unchanged. Hence, it becomes necessary to study grinding process using intermittent cutting (grooved workpiece – discontinuous cutting), as little or no knowledge and studies have been developed for this purpose, since there is nothing found in formal literature, except for grooved grinding wheels. During the grinding process, heat generated in the cutting zone is extremely high. Therefore, plenty of cutting fluids are essential to cool not only the workpiece but also the grinding wheel, improving the grinding process. In this paper, grinding trials were performed using a conventional aluminum oxide grinding wheel, testing samples made of AISI 4340 steel quenched and tempered with 2, 6, and 12 grooves. The cylindrical plunge grinding was performed by rotating the workpiece on the grinding wheel. This plunge movement was made at three different speeds. From the obtained results, it can be observed that roughness tended to increase for testing sample with the same number of grooves, as rotation speed increased. Roundness error also tended to increase as the speed rotation process got higher for testing the sample with the same number of grooves. Grinding wheel wear enhanced as rotation speed and number of grooves increased. Power consumed by the grinding machine was inversely proportional to the number of grooves. Subsuperficial microhardness had no significant change. Micrographs reveal an optimal machining operation as there was no significant damage on the machined surface.

We examine whether prosperous economic times have both immediate and lasting implications for corporate misconduct among CEOs. Drawing on research suggesting that prosperous times are associated with excessive risk-taking, overconfidence, and more opportunities to cheat, we first propose that CEOs will be more likely to engage in corporate misconduct during good economic times. Next, we propose that CEOs who begin their careers in prosperous times will be more likely to engage in self-serving corporate misconduct later in their careers. We tested these hypotheses by assembling a large dataset of American CEOs and following their stock option reporting patterns between 1996 and 2005. We found that in good economic times, CEOs were more likely to backdate their stock options grants. Moreover, CEOs who began their careers in prosperous times were more likely to backdate stock option grants later in their careers. These findings suggest that the state of the economy can influence current ethical behavior and leave a lasting imprint on the moral proclivities of new workforce entrants.

Made available in DSpace on 2018-11-26T17:15:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-09-01 Monitoring the grinding of ceramics using the vibration signal has been presented as an alternative for the diagnosis of the workpiece surface. This paper has the objective of studying the vibration signal through spectral analysis in order to monitor the grinding process, and looking for the best parameters that could be related to the surface integrity in the finished workpieces of ceramics. Thus, grinding tests were carried out on alumina ceramic specimens in different depths of cut. The workpieces were evaluated after grinding process by measuring the surface roughness Ra and confocal microscopy. For monitoring was used an accelerometer and vibration signal was collected by an oscilloscope. Digital signal processing techniques were performed, identifying a range of frequencies between 800 Hz and 2 kHz that best correlate with the condition of the machined ceramic. There was a correlation between the vibration and the integrity of the ceramics workpiece after grinding process. Moreover, the increase of the vibration is directly proportional to the surface roughness each cutting depth used. It follows that the vibration can be used to monitor the grinding of ceramics due to their relationship with the condition of the workpieces. UNESP, Fac Engn Bauru, Dept Elect Engn, Bauru, SP, Brazil UNESP, Fac Engn Bauru, Dept Engn Mecan, Bauru, SP, Brazil UNESP, Fac Engn Bauru, Dept Elect Engn, Bauru, SP, Brazil UNESP, Fac Engn Bauru, Dept Engn Mecan, Bauru, SP, Brazil

Nos processos de retificação, a utilização de fluidos de corte é uma maneira de implementar a qualidade final do processo, pois os fluidos têm como finalidade a lubrificação na área de contato entre a peça e ferramenta e a refrigeração das superfícies, assim evitando danificações na superfície da peça. Com isso, a utilização de fluidos de corte tem sido constantemente estudada, visando diminuir a utilização deste, pois a utilização de fluidos de corte tem seus problemas. O custo do produto final aumenta consideravelmente com o uso de fluidos de corte no processo de retificação, além de que os fluidos de corte são substâncias tóxicas e nocivas tanto às pessoas quanto ao meio ambiente. Portanto, indústrias, universidades e centros de pesquisas são levados a pesquisar métodos alternativos menos prejudiciais ao meio ambiente. Dentre as alternativas surge a técnica da mínima quantidade de lubrificante (MQL), que também tem suas desvantagens, como por exemplo, a formação de um borra de óleo na superfície de corte do rebolo, o que gera uma rugosidade maior na peça. Porém, visando minimizar o problema da formação da borra de óleo podem ser usados jatos de ar comprimido incidindo na superfície de corte do rebolo, com o objetivo de limpar a mesma. Este estudo será feito através da análise da avaliação das variáveis de saída do processo de retificação externa, como o comportamento da rugosidade superficial e dos desvios de circularidade. Através dos resultados obtidos pretende-se estudar a técnica do MQL, visando melhorá-la através da limpeza da superfície de corte do rebolo com jatos de ar comprimido. In grinding, the use of cutting fluids aims to improve the final quality of the process, because their purpose is to lubricate the contact area between workpiece and tool and the surface cooling, thus avoiding damages on the machined part. Therefore, this subject has been constantly studied, in order to diminish the amounts applied, due to some problems it may cause. The cost of the final product enhances considerably with the application of cutting fluids; they are environmentally hazardous substances, and the cause of many illnesses to the people involved. In this case, industries, universities and research centers are prompted to research alternative methods which are less harmful to the environment. Between these arises the minimum quantity lubricant (MQL) technique, however having also its disadvantages, like the formation of a grout on wheel surface, which generates higher surface roughness on the workpiece. Aiming to minimize the problems concerning this grout, compressed air jets can be applied in order to clean the abrasive tool, which is the subject of the present work. This study aims to analyze some output variables of the external plunge grinding as surface roughness and roundness errors. Using the obtained results, it is intended to study MQL technique, aiming its improvement through the surface cleaning of the grinding wheel by compressed air jets.

Nas últimas duas décadas, as cerâmicas avançadas têm sido exaustivamente utilizadas em aplicações na indústria devido às suas propriedades de elevada resistência ao desgaste e dureza. Entretanto, ainda se tem um alto custo agregado ao acabamento da peça. Esse acabamento geralmente é feito pelo processo de retificação, único processo economicamente viável que produz superfícies de elevada qualidade e precisão geométrica. Nesse contexto, as empresas vêm buscando a otimização no processo de retificação como, por exemplo, a redução do fluxo de fluido de corte utilizado, o que também visa atender exigências mundiais de preservação ambiental. Desta forma, este projeto pretendeu explorar a técnica da Mínima Quantidade de Lubrificação (MQL) na retificação cilíndrica externa de mergulho em cerâmicas com rebolos diamantados. Foram utilizados dois métodos de refrigeração: o convencional e o MQL, com três avanços de corte para cada caso. Foram usados um bocal convencional e um bocal para o MQL, tendo este um uniformizador de saída do jato. Foram analisadas como variáveis de saída: a emissão acústica, relação G, aspecto da superfície via microscopia eletrônica de varredura (MEV), rugosidade e circularidade. Assim, embora a refrigeração convencional ainda apresente os melhores resultados em comparação com a refrigeração com MQL, esta última pode atender os requisitos necessários para diversas aplicações, em especial quando utilizadas baixas espessuras equivalentes de corte (h eq). Além disso, a técnica de MQL possui a vantagem de gerar um menor impacto ambiental em comparação com a lubrificação convencional, devido ao uso mínimo de fluido de corte cujo descarte é cada vez mais regulamentado e custoso. Advanced ceramics have been extensively used in applications in industry in the last two decades because of their properties of high resistance to wear and hardness. Nevertheless, the finishing process highly increases the cost of pieces and components. The finishing process is, in most cases, grinding, the only viable process that produces high quality surfaces and guarantees geometric precision. In this context, companies are seeking to optimize the grinding process by, for example, reducing the usage and flow of cutting fluid, which also helps to achieve global environmental preservation requirements. Thus this project sought to exploit the technique of Minimum Quantity of Lubrication of the external cylindrical grinding in ceramics with diamond wheels. The project used two methods of cooling, the conventional and MQL, with three feed velocity in each case. We used a conventional nozzle, a mouthpiece for the MQL the latter having a uniform output of the jet. Variables were analyzed as the output acoustic emission, G relationship, surface condition by scanning electron microscopy (SEM), roughness and circularity. Even though the conventional cooling still achieves better results in some aspects, in comparison with the MQL method, the latest is able to attend the requirements for many applications, especially with lower feed velocities. Furthermore, the MQL method brings environmental benefits, due to its lower consumption, and thus disposal, of cutting fluids.

O sucesso da cerâmica estrutural na maioria das aplicações depende não somente das propriedades do material e do projeto da peça, mas também da qualidade do produto usinado. Um dos fatores citados como obstáculo à ampla utilização de componentes cerâmicos é a sua falta de confiabilidade, em função da grande dispersão dos valores de resistência mecânica provocada por defeitos que podem ter origem no processo de retificação. A retificação de cerâmica, assim como a de aços e superligas, é realizada normalmente com abundância de fluidos de corte. A utilização destes resulta em problemas ecológicos, fisiológicos e econômicos. Desde a última década, a opinião pública, o mercado, as leis e regulamentos têm pressionado as indústrias para considerar os riscos ambientais na manufatura. Com o propósito de avaliar alternativas ao método convencional de lubri-refrigeração, foi estudada a viabilidade da técnica de refrigeração otimizada, onde o fluido de corte é aplicado à mesma velocidade periférica do rebolo, penetrando na região de corte com menos turbulência. Também foi analisada a técnica da Mínima Quantidade de Lubrificação (MQL), na qual o grande volume de fluido de corte é substituído por um jato de ar contendo uma quantidade ínfima de lubrificante. Os métodos foram comparados através da análise da força tangencial de corte, rugosidade e relação G. Concluiu-se ainda que a técnica de MQL mostrou-se inviável na retificação de cerâmica nas condições propostas e que os resultados com a lubri-refrigeração otimizada não permitiram afirmar que esta resultou em melhores valores de rugosidade e relação G quando comparada com à técnica convencional. The success of structural ceramics in most applications depends not only on the materials properties and component design, but also the quality of machined products. One factor usually mentioned as a barrier to the wide use of ceramics is the lack of reliability of ceramic components, because the variability on the mechanical strength caused by defects that can be impaired in the grinding process. The grinding of ceramics, as much as with steel grinding is performed generally with excess of cutting fluids (coolants). The use of coolants results in serious ecological, physiological and economic issues. Since last decade the public opinion, the market, the laws and regulations have pushed the industries to consider the environmental risks in the manufacturing process. Then, in order to evaluate alternatives to the conventional method of cooling and lubrication, it was studied the viability of the optimized technique, where the cutting fluid is applied to the same peripherical speed of the wheel, penetrating in the cutting zone with less turbulence. Also, it was verified the technique of Minimum Quantity of Lubricant (MQL), where a large amount of cutting fluid is replaced by an air compressed flow containing a small quantity of lubricant. The methods were compared through performance analysis of cutting forces, roughness and wheel (G ratio). As a conclusion is that MQL is not viable in ceramics grinding with the working conditions proposed. The results obtained with optimized technique are insufficient to state this technique presents better roughness and G-ratio values when compared to conventional method.

Made available in DSpace on 2013-08-12T19:01:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-01-01 Made available in DSpace on 2013-09-30T18:10:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:27:25Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T13:27:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-01-01 The world tendency is the increase of the productivity and the production of pieces more and more sophisticated, with high degree of geometric and dimensional tolerances, with good surface finish and low cost. Rectification is responsible for the final finish in the machining process of a material. However, damages generated in this production phase affect all the resources used in the previous processes. Great part of the problems happennig in the rectification process is due to the enormous temperature generated in this activity because of the machining conditions. The dive speed, which is directly related to the productivity, is considered responsible for the damages that occur during rectification, limiting its values to those that do not cause such damages. In this work, through the variation of the dive speed in the process of cylindrical grinding of type ABNT D6 steel, rationalizing the application of two cutting fluids and using a CBN (cubic boron nitrate) abrasive wheel with vitrified blond, the influence of the dive speed on the surface damages of hardened steels was evaluated. The results allowed to say that the dive speed, associated to an efficient cooling and lubrication, didn't provoke thermal damages (including heated zones, cracks and tension stresses) to the material. Residual stresses and the roughness of rectified materials presented a correlation with the machining conditions. The work concluded that it is possible to increase the productivity without provoking damages in the rectified components. Univ Estadual Paulista, UNESP, Dept Eng Mecan, BR-17033360 Bauru, SP, Brazil Univ Estadual Paulista, UNESP, Dept Eng Mecan, BR-17033360 Bauru, SP, Brazil

Por meio de um trabalho multidisciplinar entre Engenheiros e Dentistas, foram estudados oito diferentes tipos de grãos abrasivos de diamantes para a fabricação de pontas adiamantadas e/ou rebolos de pequeno diâmetro. Verificou-se qual o grão mais adequado para ser empregado nas pontas, as quais são utilizadas em equipamentos que possuem um pequeno torque disponível. Uma metodologia de experimentação para avaliação da capacidade de corte destas ferramentas foi desenvolvida, utilizando-se o vidro como material a ser desgastado. Como resultados, observou-se que a estrutura e a friabilidade do grão de diamante afetam diretamente a capacidade de corte das pontas adiamantadas. Desta forma, o melhor tipo de diamante foi aquele que apresentou, ao mesmo tempo, as melhores condições de remoção de material e o menor preço. This paper presents a multi-area research involving Dentists and Engineers, in which eight different types of diamond abrasive grains, which are used in dental burs (small diameter grinding wheels) were tested. The most appropriated grain to be used in burs was evaluated. These burs are used in dental equipment characterized by low torque and low spindle rotation. A test methodology was developed in order to evaluate the cutting capacity of these burs, using glass as a machining material. The results show that it was possible to verify that the grain structure and friability were the properties that affect the cutting capacity. Consequently, the best diamond grain is the one that presented, simultaneously, the best material removal conditions and the lowest price.

O presente trabalho apresenta uma metodologia confiável e de execução rápida para a avaliação do desgaste abrasivo entre as cerâmicas Duceram e Vita nas resinas compostas Z-100 e Charisma. Estes materiais são amplamente utilizados nos consultórios e clínicas dentais para restaurações funcionais e estéticas dos dentes. Para avaliar o desgaste abrasivo entre os materiais, um disco dinâmico revestido com porcelana foi utilizado sobre um disco estático revestido com resina. Os resultados indicaram que a cerâmica Vita apresenta desgaste inferior a Duceram nas resinas analisadas. This work presents a fast and trustworthy methodology for the evaluation of the abrasive wear between the ceramics Duceram and Vita and the composites resins Z-100 and Charisma. These materials are widely used in dental clinics to restoration of function and aesthetics of the teeth. To evaluate the abrasive wear between the materials, a dynamic disk covered with ceramic was used contrary to a static disk covered with resin. The results showed that Vita presents an inferior wear against Duceram in the resins tested.

The aim of this research is to evaluate the influence of grinding and cutting conditions on surfaces of advanced ceramics ground with diamond grinding wheels containing a binding resin bond. The quality surface was analyzed by Scanning Electron Microscopy (SEM). O objetivo desta pesquisa é a avaliação da influência das condições de usinagem na superfície gerada de cerâmicas avançadas retificadas com rebolo diamantado com ligante resinóide. A qualidade superficial foi analisada utilizando-se a Microscopia Eletrônica de Varredura (MEV)

Grinding is a finish process of parts that require high precision and tight dimensional tolerance, which owe high value-added. As the grinding process takes place, the cutting surface of the grinding wheel undergoes wear and then its cutting capacity is reduced. On the other hand, the dressing operation is responsible for restoring the cutting surface of the grinding wheel and, therefore, plays a key role in the grinding process. This work aims at obtaining acoustic images of the grinding wheel surface to identify its conditions during the dressing operation. Experimental tests were conducted with a single-point diamond dresser in a surface grinding machine, which was equipped with an oxide aluminum grinding wheel in which specific marks were intentionally made on its surface to simulate damages for identification. An acoustic emission sensor was fixed to the dresser holder and the signal were acquired at 5 MHz. The signal spectrum was investigated and a frequency band was carefully selected, which represented the conditions of grinding wheel surface. The root mean square values were then computed from the raw signal with and without filtering for several integration periods, and the acoustic images obtained. The results show that the proposed technique is efficient to identify the damage on the wheel surface during the dressing operation as well as its location.

Alternative techniques such as impedance-based lead zirconate titanate (PZT) transducers has emerged as an innovative approach for manufacturing monitoring process, because its flexibility of using low-cost piezoelectric diaphragms and its simple methodology in terms of apparatus by using the electromechanical impedance (EMI). In addition, this technique has been under several improvements due to the advance of artificial intelligent systems. On this point, the use of fuzzy logic systems has been reported in literature as an attractive combination to improve the process performance. Therefore, this study proposes an approach to detect damage in multi-point dresser based on EMI technique incorporating a fuzzy logic system. To this end, a fuzzy model is built considering the information obtained from representative damage indices corresponding to the different damage cases that are generated at the dresser. At the end, authors expected that the dressing operation can be optimized, preventing the operation from being performed with worn or damaged dressers and ensuring quality standards and precision to the grinding process, which have a high benefit to the manufacturing chain.