169,888 research outputs found
Measuring thermal properties with the parallel wire method: a comparison of mathematical models
No full textDesign and Performance of a Micro-Rectenna Focal Plane Array for Thermal Energy Harvesting
No full textIn this paper, we present the design and experimental implementation of a thermal energy harvesting device. Each energy-harvesting unit cell functions as an individual micro-rectenna and, collectively, as a focal plane array (FPA). The FPA is fabricated out of a two-dimensional electron gas (2DEG) in GaAs/AlGaAs quantum well using electron beam lithography (EBL) and photolithography methods, and consists of micro-rectenna unit cells arranged on a square lattice of 11 by 11 elements. The micro-rectenna, consisting of a high-speed diode (self-switching diode) and a broadband bowtie antenna, can convert thermal radiation into dc electric power (Y. Pan, C. V. Powell, A. M. Song and C. Balocco, Applied Physics Letter, 105, 253901, 2014)
Novel low-cost ultra-high-speed diodes for electromagnetic energy harvesting
No full textThis work presents the fabrication of novel high-frequency low-cost metal-insulator-metal (MIM) diodes with the dielectric (insulating) layer formed using a chemical approach at low temperature, rather than using the more aggressive techniques typical of the semiconductor industry. This device is a useful component in a wide range of applications, including radio frequency identification (RFID), high frequency detectors and mixers, and electromagnetic energy harvesting as in (Y. Pan, C. V. Powell, A. M. Song, and C. Balocco, “Micro Rectennas: Brownian Ratchets for Thermal-Energy Harvesting”, Appl. Phys. Lett. 105, 253901, 2014)
An integrated approach to the preventive conservation of Cultural Heritage: indoor biological environmental monitoring.
No full textIn cultural-heritage-related indoor environments, biological particles represent a hazard not only to artefacts, but also to operators and visitors. Biological environmental monitoring is essential to assess any potential risk to the integrity of cultural objects and human health. We propose an integrated approach to the study of biological pollution in indoor environments, such as museums, libraries and archives, based on a methodological model for measuring microbial air and surface contamination, as well as allergens. The proposed approach relies on the analysis of 1) airborne microorganisms with active and passive methods; 2) surfaces of artefacts with non-destructive and non-invasive techniques based on nitrocellulose membrane filters; 3) fungal spores with a spore trap (Hirst type) and microscope; 4) surface and airborne allergens with immunoenzymatic assays; 5) airborne particles, with a laser particle counter; and 6) indoor microclimatic conditions, with a data logger monitoring air temperature, relative humidity, air velocity and mean radiant temperature, all combined with infrared measurements of surface temperatures. The Computational Fluid Dynamics (CFD) application for transient simulations, integrated with experimental data and applied to three dimensional models of the studied environment, is used to assess the indoor microclimate conditions. CFD plays an important role in the prediction of damage and risk, as it helps evaluate the efficiency, adequacy and reliability of ventilation systems. The CFD application can also provide critical indications for air quality control and energy saving, and can help establish maintenance criteria. Thanks to a grant by Cariparma Foundation, the proposed approach has been applied at the Palatina Library in Parma. For air microbial monitoring, a DUO-SAS 360 was used to measure the concentration of microorganisms in the air, expressed as CFU/m3 (colony forming units per cubic metre), while settle plates were used to measure the rate at which airborne microorganisms settle on surfaces (Index of Microbial Air contamination, IMA). For surface contamination, two parameters were measured using nitrocellulose membranes: the Microbial Buildup (MB, the total number of microorganisms accumulated on a surface in an unknown period of time prior to the sampling) and the Hourly Microbial Fallout (HMF, the number of microorganisms that settle on a specific surface during one hour). A spore trap sampler (VPPS 1000) was also used for direct detection at the microscope of fungal spores, both viable and nonviable, and to measure the temporal distribution of the particulate. The results obtained represent a contribution towards the definition of standardized biological environmental contamination assessment methods that will help researchers define levels and environmental classes of biological contamination. This integrated biological (air and surfaces) and microclimatic approach represents a starting point to study the environment-artefact-man system and can lead to a better understanding and prevention of biological risks both to cultural materials and to the health of operators and visitors
A fuzzy framework assessing corporate resource management for the mobile content industry
No full textThe assessment of a company's strategic endowment of resources, competencies and capabilities (R&C&Cs) and the identification of core R&C&Cs are key issues in strategy and technology management, though these processes suffer from the lack of consolidated models and methods to support their operationalization. This study proposes a Fuzzy Assessment Framework to evaluate the core status of a company's R&C&Cs, thus orienting resource management towards the actual sources of competitive advantage. The research process leverages multiple case study and fuzzy set theory to gather and analyze data from a set of twenty-six technology companies operating in the mobile content industry. The resulting Fuzzy Assessment Framework supports the concrete evaluation and management of resources and shows significant properties (i.e. accuracy, comprehensiveness, insight) thanks to the use of fuzzy measurements and Fuzzy Likert scales
The evaluation of solar energy potential and energy needs for heating and lighting using LIDAR data: Applications on two real built-up areas
No full textUsing exergy to analyze the sustainability of an urban area
No full textThe extended exergy analysis method, taking into account the mean life time cycle of building, has been applied to evaluate
the sustainability of an urban area. The impact of the emissions due to the life cycle of the buildings has been evaluated. Two
thermodynamic indexes, gI and gII showing, respectively, the first and second law efficiency of buildings, have been proposed
as thermodynamic indexes. The applied methodology provides a single thermodynamics environmental criterion for the
selection of technological alternatives, strategies and designs that produce lower environmental impacts connected to higher
exergy indexes gII
Sustainable urban block design through passive architecture: A tool that uses urban geometry optimization to compute energy savings
No full text3,5 diiodothyronine increases insulin-like growth factor binding protein-4 mRNA level in cultured hepatocytes
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