7 resultados para Second preimage resistance

em Aston University Research Archive


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Two experiments examined the extent to which attitudes changed following majority and minority influence are resistant to counter-persuasion. In both experiments participants' attitudes were measured after being exposed to two messages, delayed in time, which argued opposite positions (initial message and counter-message). In the first experiment, attitudes following minority endorsement of the initial message were more resistant to a second counter-message only when the initial message contained strong versus weak arguments. Attitudes changed following majority influence did not resist the second counter-message and returned to their pre-test level. Experiment 2 varied whether memory was warned (i.e., message recipients expected to recall the message) or not, to manipulate message processing. When memory was warned, which should increase message processing, attitudes changed following both majority and minority influence resisted the second counter-message. The results support the view that minority influence instigates systematic processing of its arguments, leading to attitudes that resist counter-persuasion. Attitudes formed following majority influence yield to counter-persuasion unless there is a secondary task that encourages message processing.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Three experiments examined the extent to which attitudes following majority and minority influence are resistant to counter-persuasion. In Experiment 1, participants’ attitudes were measured after being exposed to two messages which argued opposite positions (initial pro-attitudinal message and subsequent, counter-attitudinal counter-message). Attitudes following minority endorsement of the initial message were more resistant to a (second) counter-message than attitudes following majority endorsement of the initial message. Experiment 2 replicated this finding when the message direction was reversed (counter-attitudinal initial message and pro-attitudinal counter-message) and showed that the level of message elaboration mediated the amount of attitude resistance. Experiment 3 included conditions where participants received only the counter-message and showed that minority-source participants had resisted the second message (counter-message) rather than being influenced by it. These results show that minority influence induces systematic processing of its arguments which leads to attitudes which are resistant to counter-persuasion.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The object of this thesis is to develop a method for calculating the losses developed in steel conductors of circular cross-section and at temperatures below 100oC, by the direct passage of a sinusoidally alternating current. Three cases are considered. 1. Isolated solid or tubular conductor. 2. Concentric arrangement of tube and solid return conductor. 3. Concentric arrangement of two tubes. These cases find applications in process temperature maintenance of pipelines, resistance heating of bars and design of bus-bars. The problems associated with the non-linearity of steel are examined. Resistance heating of bars and methods of surface heating of pipelines are briefly described. Magnetic-linear solutions based on Maxwell's equations are critically examined and conditions under which various formulae apply investigated. The conditions under which a tube is electrically equivalent to a solid conductor and to a semi-infinite plate are derived. Existing solutions for the calculation of losses in isolated steel conductors of circular cross-section are reviewed, evaluated and compared. Two methods of solution are developed for the three cases considered. The first is based on the magnetic-linear solutions and offers an alternative to the available methods which are not universal. The second solution extends the existing B/H step-function approximation method to small diameter conductors and to tubes in isolation or in a concentric arrangement. A comprehensive experimental investigation is presented for cases 1 and 2 above which confirms the validity of the proposed methods of solution. These are further supported by experimental results reported in the literature. Good agreement is obtained between measured and calculated loss values for surface field strengths beyond the linear part of the d.c. magnetisation characteristic. It is also shown that there is a difference in the electrical behaviour of a small diameter conductor or thin tube under resistance or induction heating conditions.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Metakaolin (MK), a calcined clay, was included as a partial cement replacement material, at up to 20% by weight of binder, in cement pastes and concrete, and its influence on the resistance to chloride ingress investigated. Reductions in effective chloride diffusion coefficients through hardened cement paste were obtained for binary blends and by combining OPC, MK and a second cement replacement material of pulverised fuel ash or ground granulated blast furnace slag. Steady state oxygen diffusion measurements through hardened cement pastes measured using an electrochemical cell showed that the interaction between charged species and the pore surfaces is a major factor in determining chloride diffusion rate. Rheology of the binder, particularly at high MK replacement levels, was found to have a dramatic influence on the diffusion performance of cement pastes. It was concluded that plasticising admixtures are essential for adequate dispersion of MK in cement pastes. Chloride concentration profile analysis of the concrete cylinders, exposed to sodium chloride solution for one year, was employed to obtain apparent chloride diffusion coefficients for concrete specimens. MK was found to reduce the depth of chloride penetration into concrete when compared with that of unblended mixes. Corrosion rate and corrosion potential measurements were taken on steel bars embedded in concrete exposed to a saline environment under conditions of cyclic wetting and drying. The initiation time for corrosion was found to be significantly longer for MK blended mixes than for plain OPC systems. The aggregate-paste interfacial zone of MK blended systems was investigated by steady state diffusion of chloride ions through mortar containing glass beads as model aggregate. For the model aggregate specimens tested the work confirmed the hypothesis that properties of the bulk paste are the controlling factors in ionic diffusion through mortar.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This thesis examines the involvement of the French Freemason movement in the Resistance during the Occupation of France by the Germans 1939-1945, its relationship with the Vichy government and the effect the 'Nouvelle Révolution' had on the lives of individual Masons. To set the scene and to put the role of Freemasonry into perspective in the life of France and the French political system, the origins of French Freemasonry are examined and explained. The main French Masonic obediences are discussed and the differences between them emphasised. The particular attributes of a Freemason are described and the ideals and ethos of the Order is discussed. From its earliest days, Freemasonry has often been persecuted by the Roman Catholic Church or by extreme Right-wing movements. The history of this persecution is reviewed and the reasons for its persistence noted, with especial emphasis on the treatment of Freemasons under the fascist regimes of Italy and Germany. The fate of Freemasonry in countries under German control is also briefly examined. With the occupation of France by the Germans, the differences and similarities of the treatment of French and German Freemasons are discussed. The processes and legislation of this ban are closely examined and the part played by the Vichy government in the persecution of French Freemasonry is discussed. The effects of this persecution and the consequences for individuals are examined and the Freemason's role in the emerging Resistance movement is reviewed. The contribution of many lodges to the Resistance movement is examined and the sacrifice of many Freemasons for their ideals is emphasised.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Multidrug resistance protein 1 (MRP1/ABCC1) is an ATP-dependent polytopic membrane protein that transports many anticancer drugs and organic anions. Its transport mechanism is multifaceted, especially with respect to the participation of GSH. For example, vincristine is cotransported with GSH, estrone sulfate transport is stimulated by GSH, or MRP1 can transport GSH alone, and this can be stimulated by compounds such as verapamil or apigenin. Thus, the interactions between GSH and MRP1 are mechanistically complex. To examine the similarities and differences among the various GSH-associated mechanisms of MRP1 transport, we have measured first the effect of GSH and several GSH-associated substrates/modulators on the binding and hydrolysis of ATP by MRP1 using 8-azidoadenosine-5'-[(32)P]-triphosphate ([(32)P]azidoATP) analogs, and second the initial binding of GSH and GSH-associated substrates/modulators to MRP1. We observed that GSH or its nonreducing derivative S-methylGSH (S-mGSH), but none of the GSH-associated substrate/modulators, caused a significant increase in [gamma-(32)P]azidoATP labeling of MRP1. Moreover, GSH and S-mGSH decreased levels of orthovanadate-induced trapping of [alpha-(32)P]azidoADP. [alpha-(32)P]azidoADP.Vi trapping was also decreased by estone sulfate, whereas vincristine, verapamil, and apigenin had no apparent effects on nucleotide interactions with MRP1. Furthermore, estrone sulfate and S-mGSH enhanced the effect of each other 15- and 10-fold, respectively. Second, although GSH binding increased the apparent affinity of MRP1 for all GSH-associated substrates/modulators tested, only estrone sulfate had a reciprocal effect on the apparent affinity of MRP1 for GSH. Overall, these results indicate significant mechanistic differences between MRP1-mediated transport of GSH and the ability of GSH to modulate MRP1 transport.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This chapter investigates the conflicting demands faced by web designers in the development of social e-atmospherics that aim to encourage e-value creation, thus strengthening and prolonging market planning strategies. While recent studies have shown that significant shifts are occurring concerning the importance of users’ generated content by way of social e-communication tools (e.g. blogs), these trends are also creating expectations that social and cultural cues ought to become a greater part of e-atmospherics and e-business strategies. Yet, there is growing evidence that organizations are resisting such efforts, fearing that they will lose control of their e-marketing strategy. This chapter contributes to the theory and literature on online cross-cultural understanding and the impact website designers (meso-level) can have on improving the sustainability of e-business planning, departing from recent studies that focus mainly on firms’ e-business plans (macro-level) or final consumers (micro-level). A second contribution is made with respect to online behavior regarding the advancement of technologies that facilitate the development and shaping of new social e-atmospherics that affect users’ behavior and long term e-business strategies through the avoidance of traditional, formal decision making processes and marketing strategy mechanisms implemented by firms. These issues have been highlighted in the literature on the co-production and co-creation of value, which few organizations have thus far integrated in their strategic and pragmatic e-business plans. Drawing upon fifteen online interviews with web designers in the USA, as key non-institutional actors at the meso-level who are developing what future websites will be like, this chapter analyzes ways in which identifying points of resistance and conflicting demands can lead to engagement with the debate over the online co-creation of value and more sustainable future e-business planning. A number of points of resistance to the inclusion of more e-social atmospherics are identified, and the implications for web designers’ roles and web design planning are discussed along with the limitations of the study and potential future research for e-business studies.