349 research outputs found
Prevenção da formação de hidratos em gasodutos submarinos
Ao longo do processo de transporte do gás natural em gasodutos submarinos atĂ© as Unidades de Processamento, a indĂşstria petrolĂfera pode enfrentar diversos problemas, dentre eles, a formação de hidratos. O ambiente submarino possui condições propicias de pressĂŁo (alta) e temperatura (baixa) para que estas estruturas sĂłlidas se formem. Os hidratos sĂŁo problemas crĂticos para a garantia de escoamento, pois podem causar entupimento das tubulações, prisĂŁo e problemas de acionamento em equipamentos, podem comprometer a produtividade das operações, aumentar custos de produção e consumo de energia, alĂ©m de gerar danos aos equipamentos e as estruturas, comprometendo a segurança das atividades e em casos mais extremos, causando a paralisação completa da produção. Por isso, faz-se necessário adotar medidas de controle, planejamento e monitoramento das condições termodinâmicas as quais o gás natural está sendo transportado. Neste trabalho sĂŁo simuladas as condições prĂłximas das reais enfrentadas durante o transporte do gás natural produzido na Unidade de Produção de PetrĂłleo e Gás Natural FPSO Cidade de VitĂłria atĂ© a Unidade de Tratamento de Gás de Cacimbas. Para verificar as propriedades de fluxo do sistema, a temperatura e a pressĂŁo de formação dos hidratos, e dimensionar de forma otimizada o uso de mĂ©todos quĂmicos (inibidores) e mĂ©todos tĂ©rmicos (aquecedores) de prevenção será utilizado o software HYSYS. Os resultados obtidos comprovam a eficiĂŞncia do inibidor termodinâmico metanol na prevenção da formação do hidrato e as vazões necessárias para realizar este controle. AlĂ©m disso, indica-se a quantidade de energia necessária para que um aquecedor elĂ©trico forneça calor suficiente Ă tubulação para prevenir a formação de hidratos, mostrando que este mĂ©todo tĂ©rmico pode substituir a injeção do metanol, porĂ©m Ă© necessário avaliar o requisito energĂ©tico, que pode ser elevado.
Palavras-chave: transporte de gás natural; escoamento transiente; hidrato; inibidores de hidrato
Skid Resistance of Pavement Marking Materials Volume 1
DOT-FH-11-9443The skid resistance of typical pavement marking materials is determined. A data base of full-scale locked-wheel skid resistance is presented for typical traffic paints of various formulations, hot spray and extruded thermoplastics, cold preformed plastics, temporary tapes, and some two-part systems. A variety of pavement surface types including dense and open graded asphalt and portland cement concrete are used in the study. In Volume I texture data are presented for field applications and for laboratory samples. Equations are developed for predicting skid resistance from texture measurements. The effects of glass beads, weathering, and polishing are examined in laboratory and field experiments. Based on a simulation, guidelines are developed for the maximum acceptable differential skid resistance between a pavement and the marking materials on it. Both two-and four-wheel vehicles are treated. Volume II of this report contains a complete listing of the data compiled in this project and is available in limited quantities to interested researchers. A summary of all the data which was utilized in the formation of the conclusions are included in tables of Volume I
Anti-Allergic Cromones Inhibit Histamine and Eicosanoid Release from Activated Human and Murine Mast Cells by Releasing Annexin A1
PMCID: PMC3601088This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Time-dynamic effects on the global temperature when harvesting logging residues for bioenergy
The climate mitigation potential of using logging residues (tree tops and branches) for bioenergy has been debated. In this study, a time-dependent life cycle assessment (LCA) was performed using a single-stand perspective. Three forest stands located in different Swedish climate zones were studied in order to assess the global temperature change when using logging residues for producing district heating. These systems were compared with two fossil reference systems in which the logging residues were assumed to remain in the forest to decompose over time, while coal or natural gas was used for energy. The results showed that replacing coal with logging residues gave a direct climate benefit from a single-stand perspective, while replacing natural gas gave a delayed climate benefit of around 8-12 years depending on climate zone. A sensitivity analysis showed that the time was strongly dependent on the assumptions for extraction and combustion of natural gas. The LCA showed that from a single-stand perspective, harvesting logging residues for bioenergy in the south of Sweden would give the highest temperature change mitigation potential per energy unit. However, the differences between the three climate zones studied per energy unit were relatively small. On a hectare basis, the southern forest stand would generate more biomass compared to the central and northern locations, which thereby could replace more fossil fuel and give larger climate benefits
Airfield pavement deterioration assessment using stress-dependent neural network models
Chinese students in a UK business school: hearing the student voice in reflective teaching and learning practice.
This paper presents the outcomes of a study carried out in 2001-2002 with nine postgraduate students from China, enrolled on taught master's programmes in a UK university business school. The aims of the research were to explore the development of the students' orientations to learning during their year of study in the UK, and to explore how the researcher's interactions with the study group contributed to her professional reflections and influenced her academic practice. The main conclusions of the project were that participants' underlying approaches to learning did not change substantially over the year, owing to the culturally implicit nature of UK academic conventions and that they experienced high levels of emotional isolation and loneliness, which affected their academic confidence
Improving financial capability: the mediating role of financial behaviour
This paper investigates the collective impact of financial literacy and inclusion on individuals’ financial capability focusing on the mediating role of financial behaviour. The research is conducted on an individual-level survey. The relationships were examined by using PLS-SEM. Financial capability can be improved by increasing individuals’ financial knowledge, financial behaviour and promoting their inclusion in financial services. Furthermore, the indirect effect of financial knowledge and attitude on financial capability is found to be significant, highlighting the importance of financial behaviour. The results assist policymakers and industry leaders in understanding the most influential factors on financial capability in the context of a post-communist transition country. This enables them to design policies and services aimed at equipping citizens with knowledge and skills to make best use of their financial resources. © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Internal Grant Agency of FaME TBU [IGA/FaME/2019/002
Writing Toward Readers\u27 Better Health: A Case Study Examining the Development of Online Health Information
Each year, more people search the Internet for health information. Through a case study conducted at a prominent health information company, I will show that technical communicators are well suited to contribute to the development of online health information. Like other technical communicators, online health information developers must make rhetorical choices based on audience needs, function within specific social contexts, and work through challenges of writing, editing, and project management
What Affects Social Attention? Social Presence, Eye Contact and Autistic Traits
Social understanding is facilitated by effectively attending to other people and the subtle social cues they generate. In order to more fully appreciate the nature of social attention and what drives people to attend to social aspects of the world, one must investigate the factors that influence social attention. This is especially important when attempting to create models of disordered social attention, e.g. a model of social attention in autism. Here we analysed participants' viewing behaviour during one-to-one social interactions with an experimenter. Interactions were conducted either live or via video (social presence manipulation). The participant was asked and then required to answer questions. Experimenter eye-contact was either direct or averted. Additionally, the influence of participant self-reported autistic traits was also investigated. We found that regardless of whether the interaction was conducted live or via a video, participants frequently looked at the experimenter's face, and they did this more often when being asked a question than when answering. Critical differences in social attention between the live and video interactions were also observed. Modifications of experimenter eye contact influenced participants' eye movements in the live interaction only; and increased autistic traits were associated with less looking at the experimenter for video interactions only. We conclude that analysing patterns of eye-movements in response to strictly controlled video stimuli and natural real-world stimuli furthers the field's understanding of the factors that influence social attention
- …