541 research outputs found
Aligning City Forest Management by Engaging Community Partners in New York City
New York City contains 10,000 acres of forested natural areas, 8.5 million residents, and dozens of organizations dedicated to improving the condition of natural areas. The New York City Department of Parks and Recreation (NYC Parks) manages the majority 7,300-acres of natural area forests through hands-on work and contracts overseen by the Division of Forestry, Horticulture and Natural Resources. Additional capacity to manage and steward NYC Parks’ forest resources is created through nurturing community organizations by the non-profit Natural Areas Conservancy (NAC). Here I discuss how NAC’s Conservancy Engagement Program is aligning forest management under NYC’s forest management plan to care for the forest
Designing assistive technology for getting more independence for blind people when performing everyday tasks: an auditory-based tool as a case study
Everyday activities and tasks should in theory be easily carried by everyone, including the blind. Information and Communication Technology (ICT) has been widely used for supporting solutions. However, the solutions can be problematic for the visually impaired since familiarity with digital devices is often required. Or, indeed the procedure can be perceived as fiddly or impractical particularly for repetitive tasks due to the number/type of steps required to complete the task. This paper introduces a simple audio-based tool aimed at supporting visually-impaired people in the seemingly simple activity of checking whether the light in a room is on or off. It is an example of potential low tech devices that can be designed without the need for specific skills or knowledge by the user, and that functions in a practical way. In this context, we discuss the main issues and considerations for totally blind users in identifying whether a light is switched on. The proposed prototype is based on a simple circuit and a form of auditory feedback which informs the user whether they are switching on or off the light. Two prototypes have been designed and built for two different kinds of installation. For the subsequent second prototype, three different versions are proposed to provide a blind person with further support in easily identifying the light status at home. The new design includes enhanced auditory feedback and modifications to the dimensions. The evaluation conducted by involving various groups of end-users revealed the usefulness of the proposed tool. In addition, a survey conducted with 100 visually-impaired people reported the limitations and difficulties encountered by the blind in using existing devices. Moreover, the study revealed the interest from 94% of the participants for a potential (new) basic tool integrable with the existing lighting system. This study gives a contribution in the ambient intelligence field by (1) showing how an auditory-based tool can be used to support totally blind people to check the lights in an autonomous and relatively simple way; (2) proposing an idea that can be exploited in other application cases that use light feedback; and (3) proposing seven potential recommendations for designing assistive technology tools and common everyday devices, based on information gathered from the online survey
Group Field Theories and Phase Transitions: Revisiting the Problem of Spacetime Emergence
With the present paper I maintain that the group field theory (GFT) approach to quantum gravity can help us clarify and distinguish the problems of spacetime emergence from the questions about the nature of the quanta of space. I will show that the mechanism of phase transition suggests a form of indifference between scales (or phases) and that such an indifference allows us to black-box questions about the nature of the ontology of the fundamental levels of the theory. I consider the GFT approach to quantum gravity which derives spacetime as an emergent property from abstract non-geometrical tetrahedra through a processes of phase transition. Because the physical interpretation of the tetrahedra is problematic in view of their (non)-spatiotemporal nature, I will apply the considerations about phase transitions to GFT and conclude that the fundamental ontology of the theory and the mechanism of spacetime emergence can and should be treated separately
Post-test simulations for the NACIE-UP benchmark by STH codes
This paper illustrates the results obtained in the last phase of the NACIE-UP benchmark activity foreseen inside the EU SESAME Project. The purpose of this research activity, performed by system thermal–hydraulic (STH) codes, is finalized to the improvement, development and validation of existing STH codes for Heavy Liquid Metal (HLM) systems. All the participants improved their modelling of the NACIE-UP facility, respect to the initial blind simulation phase, adopting the actual experimental boundary conditions and reducing as much as possible sources of uncertainty in their numerical model. Four different STH codes were employed by the participants to the benchmark to model the NACIE-UP facility, namely: CATHARE for ENEA, ATHLET for GRS, RELAP5-3D© for the “Sapienza” University of Rome and RELAP5/Mod3.3(modified) for the University of Pisa. Three reference tests foreseen in the NACIE-UP benchmark and carried out at ENEA Brasimone Research Centre were analysed from four participants. The data from the post-test analyses, performed independently by the participant using different STH codes, were compared together and with the available experimental results and critically discussed
Experimental characterization of leak detection systems in HLM pool using LIFUS5/Mod3 facility
In the framework of the European Union MAXSIMA project, the safety of the steam generator (SG) adopted in the primary loop of the Heavy Liquid Metal Fast Reactor has been studied investigating the consequences and damage propagation of a SG tube rupture event and characterizing leak rates from typical cracks. Instrumentation able to promptly detect the presence of a crack in the SG tubes may be used to prevent its further propagation, which would lead to a full rupture of the tube. Application of the leak-before-break concept is relevant for improving the safety of a reactor system and decreasing the probability of a pipe break event. In this framework, a new experimental campaign (Test Series C) has been carried out in the LIFUS5/Mod3 facility, installed at ENEA Centro Ricerche Brasimone, in order to characterize and to correlate the leak rate through typical cracks occurring in the pressurized tubes with signals detected by proper transducers. Test C1.3_60 was executed injecting water at about 20 bars and 200°C into lead-bismuth eutectic alloy. The injection was performed through a laser microholed plate 60 μm in diameter. Analysis of the thermohydraulic data permitted characterization of the leakage through typical cracks that can occur in the pressurized tubes of the SG. Analysis of the data acquired by microphones and accelerometers highlighted that it is possible to correlate the signals to the leakage and the rate of release
Experimental and RELAP5-3D results on IELLLO (Integrated European Lead Lithium LOop) operation
The experimental facility IELLLO (Integrated European Lead Lithium LOop) was designed and installed at the ENEA Brasimone Research Centre to support the design of the HCLL TBM (Helium Cooled Lithium Lead Test Blanket Module).This work presents the results of the experimental campaign carried out within the framework of F4E-FPA-372 and which had three main objectives. First, to produce new experimental data for flowing LLE (Lead-Lithium Eutectic) for an analysis of the loop and the characterization of its main components. Then, to evaluate performances of commercial instrumentation as available instrumentation is not designed for use in LLE. Lastly, to use the data for validation of the model developed with the system code RELAP5-3D. The data collected could prove helpful to analyze the behavior of the LLE loop of ITER and DEMO in accidental conditions.The results show that the regenerative countercurrent heat exchanger has an efficiency ranging from 70 to 85%, mainly depending on the LLE mass flow rate. It was verified that the air cooler has the capability to keep the cold part of the loop at 623. K, even in the most demanding situation (700. rpm and maximum temperature of the hot part). The instrumentation tested showed good accuracy, with the exception of the turbine flow meter. Nevertheless, specific limitations in the upper operative temperatures were found for the LLE direct contact pressure transducer. RELAP5-3D simulations fit very well the associated experimental results achieved
Experimental and Numerical Results of LIFUS5/Mod3 Series E Test on In-Box LOCA Transient for WCLL-BB
The in-box LOCA (Loss of Coolant Accident) represents a major safety concern to be addressed in the design of the WCLL-BB (water-cooled lead-lithium breeding blanket). Research activities are ongoing to master the phenomena and processes that occur during the postulated accident, to enhance the predictive capability and reliability of numerical tools, and to validate computer models, codes, and procedures for their applications. Following these objectives, ENEA designed and built the new separate effects test facility LIFUS5/Mod3. Two experimental campaigns (Series D and Series E) were executed by injecting water at high pressure into a pool of PbLi in WCLL-BB-relevant parameter ranges. The obtained experimental data were used to check the capabilities of the RELAP5 system code to reproduce the pressure transient of a water system, to validate the chemical model of PbLi/water reactions implemented in the modified version of SIMMER codes for fusion application, to investigate the dynamic effects of energy release on the structures, and to provide relevant feedback for the follow-up experimental campaigns. This work presents the experimental data and the numerical simulations of Test E4.1. The results of the test are presented and critically discussed. The code simulations highlight that SIMMER code is able to reproduce the phenomena connected to PbLi/water interaction, and the relevant test parameters are in agreement with the acquired experimental signals. Moreover, the results obtained by the first approach to SIMMER-RELAP5 code-coupling demonstrate its capability of and strength for predicting the transient scenario in complex geometries, considering multiple physical phenomena and minimizing the computational cost
HLMC Fuel Pin Bundle characterization in CIRCE-ICE pool facility
Abstract. This work, carried out at the DICI of Pisa University, in collaboration with ENEA Brasimone R.C., deals with the analysis and a preliminary discussion of the experimental tests performed in the Integral Circulation Experiment (ICE) configuration of the Circulation Eutectic (CIRCE) facility aiming to investigate the heat transfer in fuel rod bundle. The facility test section basically consists of an electrical bundle (FPS) made up of 37 pins arranged in a hexagonal wrapped lattice with a pitch to diameter ratio of 1.8. Along the FPS active length, two sections were instrumented to monitor the heat transfer coefficient along the bundle as well as the cladding temperatures at different ranks of the sub-channels. In particular, forced circulation condition tests were performed imposing a temperature difference through the FPS and a LBE mass flow rate through the FPS. Nusselt number in the sub-channels was calculated as function of the Peclet number and obtained results were compared to Nusselt numbers computed from correlations available in Heavy Liquid Metals (HLM) literature. Results shown that the Nu is slightly lower in the middle section (section 1) if compared with the ones into the upper section (section 3), and that behaviour is probably due to the turbulence of the flow which seems to be fully developed only in the upper part of the fuel pin bundle. Anyway the Nu number, calculated as function of the Pe number in the range Pe~1500Ă·3000 (forced circulation condition), matches well the numerical correlation available for HLM fuel pin bundle, (i.e. Ushakov and Mikityuk)
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