Computational evaluation of hydraulic system behaviour with entrapped air under rapid pressurization

The pressurization of hydraulic systems containing entrapped air is considered a critical condition for the infrastructure's security due to transient pressure variations often occurred. The objective of the present study is the computational evaluation of trends observed in variation of maximum surge pressure resulting from rapid pressurizations. The comparison of the results with those obtained in previous studies is also undertaken. A brief state of art in this domain is presented. This research work is applied to an experimental system having entrapped air in the top of a vertical pipe section. The evaluation is developed through the elastic model based on the method of characteristics, considering a moving liquid boundary, with the results being compared with those achieved with the rigid liquid column model.

Computational evaluation of hydraulic system behaviour with entrapped air under rapid pressurization

The pressurization of hydraulic systems containing entrapped air is considered a critical condition for the infrastructure's security due to transient pressure variations often occurred. The objective of the present study is the computational evaluation of trends observed in variation of maximum surge pressure resulting from rapid pressurizations. The comparison of the results with those obtained in previous studies is also undertaken. A brief state of art in this domain is presented. This research work is applied to an experimental system having entrapped air in the top of a vertical pipe section. The evaluation is developed through the elastic model based on the method of characteristics, considering a moving liquid boundary, with the results being compared with those achieved with the rigid liquid column model.

Phex: a computational tool for plate heat exchanges design problems

This paper presents a computational tool (PHEx) developed in Excel VBA for solving sizing and rating design problems involving Chevron type plate heat exchangers (PHE) with 1-pass-1-pass configuration. The rating methodology procedure used in the program is outlined, and a case study is presented with the purpose to show how the program can be used to develop sensitivity analysis to several dimensional parameters of PHE and to observe their effect on transferred heat and pressure drop.

In journalism, we are all men: material voices in the production of gender meanings

This study uses qualitative data to examine how male and female professionals in newsrooms experience and vocalize gender both in their lifeworlds and in media production in general. The research was based on semi-structured interviews with 18 Portuguese journalists. The responses were analysed through phenomenological and feminist lenses and indicated the issues men and women considered salient or negligible within our realms of inquiry. The study used the lived experience of the media professionals to identify two clusters of meaning that help explain how material practices and norms in journalism are lived and understood in the newsroom: gender views in journalism and gender differences in day-to-day professional life. Overall, the findings confirm that organizational factors and the traditional gender system play important roles in journalists’ attitudes and perceptions about the role of gender in their work. The results are significant because they show how gender is simultaneously embodied and denied by both female and male journalists in a process of phenomenological “typification” and adoption of a “natural attitude” towards the gender system that may prevent the disclosure of new possibilities and understandings of the objective social world and of our gender relations.