Flat plate and turbine vane film-cooling performance with laid-back fan-shaped holes

Shaped holes are considered as an effective solution to enhance gas turbine film-cooling performance, as they allow to increase the coolant mass-flux, while limiting the detrimental lift-off phenomena. A great amount of work has been carried out in past years on basic flat plate configurations while a reduced number of experimental works deals with a quantitative assessment of the influence of curvature and vane pressure gradient. In the present work PSP (Pressure Sensitive Paint) technique is used to detail the adiabatic effectiveness generated by axial shaped holes with high value of Area Ratio close to 7, in three different configurations with the same 1:1 scale: first of all, a flat plate configuration is examined; after that, the film-cooled pressure and suction sides of a turbine vane model are investigated. Tests were performed varying the blowing ratio and imposing a density ratio of 2.5 . The experimental results are finally compared to the predictions of two different correlations, developed for flat plate configurations

Effect of Rotation and Hole Arrangement in Cold Bridge-Type Impingement Cooling Systems

Experimental activity has been performed to study different impingement cooling schemes in static and rotating conditions. Geometry replicates a leading-edge cold bridge system, including a radial supply channel and five rows of film-cooling and showerhead holes. Two impingement geometries have been studied, with different numbers of holes and diameters but with equal overall passage area. Reynolds numbers up to 13,800 and rotation numbers up to 0.002 have been investigated (based on an equivalent slot width). Tests have been performed using a novel implementation of transient heat transfer technique, which allows correct replication of the sign of buoyancy forces by flowing ambient temperature air into a preheated test article. Results show that complex interactions occur between the different features of the system, with a particularly strong effect of jet supply condition. Rotation further interacts with these phenomena, generally leading to a slight decrease in heat transfer

Effusion Cooling Plates for Combustor Liners: Experimental and Numerical Investigations on the Effect of Density Ratio

AbstractEffusion cooling represents the state-of-the-art of liner cooling technology for modern combustors. The present paper describes experimental tests aiming at evaluating the cooling performance of a multi-perforated plate in real engine representative fluid- dynamic conditions. Adiabatic effectiveness maps were obtained following the mass transfer analogy by the use of Pressure Sensitive Paint. In addition, a CFD campaign was performed in order to benchmark the reliability in estimating the cooling performance of effusion cooling liners. In order to include anisotropic diffusion effects, the k − ω SST turbulence model was corrected considering a tensorial definition of the eddy viscosity with an algebraic correction to dope its stream-span components

Prospettive e potenzialità della digitalizzazione del settore forestale in Italia

Information and Communication Technologies (ICT) play a key role for improving the implementation of sustainable forest management at local, regional, and global level. The ICT potential to easily exploit a wider and more up-to-date set of information on the economic, environmental, and so- cial value of forests is of relevant help for the daily work of technicians, land owners, and companies in boosting the efficiency and effectiveness of forest management. The concept of “Precision Forestry” (PF) was developed from the early 2000s, as a branch of precision farming or precision agriculture. PF includes the use of ICT, remote and proximal sensing technologies, and other devices to coordinate and control several processes on a spatial scale (“Precision”) for monitoring, planning, and managing forest resources (“Forestry”). The aim of this monography is to collect and describe some of the most important PF experiences applied or potential- ly useful for the Italian forestry sector. It may represent a reference guide for the stakeholders, such as forest owners, professional technicians, public administrators, and policy makers. The book includes eleven chapters reviewing the main tech- nological tools available in the Italian context and the most recent advances of ICT in forestry, also focusing on the strengths and weaknesses of their practical implementation. The opportunities and challenges of implementing PF meth- ods, practices and technologies are also discussed. In the first two chapters the precision forestry concept and its historical development are introduced. In the third chap- ter some basic elements of ICT, GIS, Global Navigation Satellite Systems (GNSS), remote/proximal sensing, and related technologies which are essential for a better compre- hension of PF applications are recalled. In chapter 4 recent advances in large scale forest inventories with a focus on mapping and on the spatial estimation of forest variables integrating field surveys and multisource re- motely sensed data are described. Current advancements in the acquisition of field information including Terrestrial La- ser Scanning (TLS), new digital dendrometers, tree-talkers, terrestrial cameras, and APP for portable devices such as smartphones or tablets for dendrometric tree measures and new citizen science applications to support quantitative and qualitative spatial estimation of forest variables over large areas (i.e., forest health, fuel types) are also presented. The chapter ends up with the description of some experiences in the implementation of Forest Information Systems in Italy to provide a simple open-access to such new generation of spatial forest information. In chapter 5 PF tools, instruments, and technologies to sup- port sustainable forest management are illustrated. APPs developed to acquire field plots data to simulate manage- ment operations, the application of photogrammetric tech- nologies from Unmanned Aerial Vehicles and TLS data for monitoring with high-spatial scale forest monitoring and for acquiring indicators at single tree level are presented. A de- tailed description of new user-friendly tools for forest roadplanning, design and construction, as well as forest opera- tion planning is also included. Precision forest tree farming (with particular reference to poplar cultivation), useful to promote and increase the prof- itability and sustainability of forest plantations within the Italian context is described in chapter 6. The innovation and enhancement within the supply chain of wood plantations (from planting to harvesting, including monitoring and identification of stress) by soil proximal sensing techniques, Early Warning Systems, and specific software are highlight- ed. Considering the even higher market demands, promoted by the large-scale planting programs for climate changes mit- igation and the demands for propagation material for en- vironmental recovery, innovative techniques and methods supported by ICT in the forest nursery sector are described in chapter 7. In chapter 8 available technologies related to precision har- vesting are analyzed and described taking into consideration the wood chain efficiency, by means of improved commu- nications between the owner/buyer and operators as well as among machineries used in forest operations, health and safety of forest operators, environmental impacts mitigation and recovery, and operators training. Advanced communi- cation systems and sensors for the exchange of data and information between machines, machine-equipments and/or machine-operators, teleoperations and automation are also described. Chapters 9 and 10 are related to wood products traceabil- ity, timber quality assessment as well as the technologies for the optimization of wood transformation processes. The concepts of wood product traceability and tracing, togeth- er with latest digital technologies for the identification and tracking of the logs (i.e., fingerprinting and RFID), are de- tailly reported. Chapter 11 is finally dedicated to the relationship between the EU policy framework and the digitalization process in both agricultural and forestry sectors. The book summarizes, under a proactive and homogeneous framework, PF methods, tools and technologies in relation with the digital transition of the Italian forestry sectors. The authors hope this book will be useful for improving the implementation of sustainable forest management practic- es at all levels in Italy, providing a comprehensive review useful for policy makers, technicians, forestry owners and students

A Qualitative Exploration of the Use of Contraband Cell Phones in Secured Facilities

Offenders accepting contraband cell phones in secured facilities violate state corrections law, and the possession of these cell phones is a form of risk taking behavior. When offenders continue this risky behavior, it affects their decision making in other domains where they are challenging authorities; and may impact the length of their incarceration. This qualitative phenomenological study examined the lived experience of ex-offenders who had contraband cell phones in secured correctional facilities in order to better understand their reasons for taking risks with contraband cell phones. The theoretical foundation for this study was Trimpop\u27s risk-homeostasis and risk-motivation theories that suggest an individual\u27s behaviors adapt to negotiate between perceived risk and desired risk in order to achieve satisfaction. The research question explored beliefs and perceptions of ex-offenders who chose to accept the risk of using contraband cell phones during their time in secured facilities. Data were collected anonymously through recorded telephone interviews with 8 male adult ex-offenders and analyzed using thematic content analysis. Findings indicated participants felt empowered by possession of cell phones in prison, and it was an acceptable risk to stay connected to family out of concern for loved ones. The study contributes to social change by providing those justice system administrators, and prison managers responsible for prison cell phone policies with more detailed information about the motivations and perspectives of offenders in respect to using contraband cell phones while imprisoned in secured facilities

Cultural Geography in Brazil and its diffusion: from 1990 to 2022

A Geografia Cultural enquanto sub-campo da ciência geográfica conjuga pesquisadores que vêm apresentando contribuições importantes ao estudo da espacialidade da cultura na Geografia Humana. Neste contexto, a tese objetiva compreender o impacto e consequente difusão de seu percurso ao longo de trinta anos no intuito de apontar contribuições para o pensamento geográfico brasileiro. O aporte metodológico da abordagem contextual de Berdoulay (2013) ancorou a pesquisa pelo exercício de revisão e discussão de sua historiografia ao compararmos diferentes perspectivas geográficas sobre cultura, tendo sido entrevistas e respostas de questionário utilizadas para respaldar narrativas relacionadas aos fatores que influenciaram o desdobramento desta perspectiva de estudo geográfico. A investigação se deu por meio de análise da produção científica sobre abordagens culturais na Geografia brasileira, principalmente as relacionadas com a Geografia Cultural, como dissertações de mestrado, teses de doutorado, artigos em periódicos, tendo também sido verificados grupos e linhas de pesquisa e ementas de disciplinas nos âmbitos da graduação e pós-graduação, além do mapeamento de sua ocorrência em universidades e centros de pesquisas no Brasil. Destacamos enquanto resultado o panorama teórico-metodológico da Geografia Cultural de 1990 a 2020, que à guisa de conclusão indica um trajeto percorrido na forma de tríade, marcado pela influência de uma tradição teórica, uma tendência no tratamento da cultura e o ecletismo metodológicoCultural Geography, as a sub-field of geographic science, brings together researchers who have been presenting important contributions to the study of the spatiality of culture in Human Geography. In this context, the thesis aims to understand the impact and consequent diffusion of its path over thirty years in order to point out contributions to Brazilian geographic thought. The methodological contribution of the contextual approach of Berdoulay (2013) anchored the research through the exercise of review and discussion of his historiography when comparing different geographical perspectives on culture, with interviews and questionnaire responses used to support narratives related to the factors that influenced the unfolding of this geographic study perspective. The investigation was carried out through the analysis of scientific production on cultural approaches in Brazilian Geography, mainly those related to Cultural Geography, such as master\'s dissertations, doctoral theses, articles in periodicals, groups and lines of research and menus disciplines offered in the graduate and undergraduate fields, in addition to mapping their occurrence in universities and research centers in Brazil. As a result, we highlight the theoretical-methodological panorama of Cultural Geography from 1990 to 2020, which, by way of conclusion, indicates a path traveled in the form of a triad, marked by the influence of a theoretical tradition, a trend in the treatment of culture and methodological eclecticis