Versatile Confocal Raman Imaging Microscope Built from Off-the-Shelf Opto-Mechanical Components

Confocal Raman microscopic (CRM) imaging has evolved to become a key tool for spatially resolved, compositional analysis and imaging, down to the μm-scale, and nowadays one may choose between numerous commercial instruments. That notwithstanding, situations may arise which exclude the use of a commercial instrument, e.g., if the analysis involves toxic or radioactive samples/environments; one may not wish to render an expensive instrument unusable for other uses, due to contamination. Therefore, custom-designed CRM instrumentation—being adaptable to hazardous conditions and providing operational flexibility—may be beneficial. Here, we describe a CRM setup, which is constructed nearly in its entirety from off-the-shelf optomechanical and optical components. The original aim was to develop a CRM suitable for the investigation of samples exposed to tritium. For increased flexibility, the CRM system incorporates optical fiber coupling to both the Raman excitation laser and the spectrometer. Lateral raster scans and axial profiling of samples are facilitated by the use of a motorized xyz-translation assembly. Besides the description of the construction and alignment of the CRM system, we also provide (i) the experimental evaluation of system performance (such as, e.g., spatial resolution) and (ii) examples of Raman raster maps and axial profiles of selected thin-film samples (such as, e.g., graphene sheets)

Statistical Modelling of Computer Systems: A Review

This paper briefly reviews the data dependent statistical methods useful for computer systems modelling. The techniques are classified according to their applicability toward comparison, tuning and design of computer systems. A review of publications dealing with statistical modeling of computer systems is presented and a comprehensive bibliography is included to provide a useful source of reference toward the present and potential applications of statistical methods for computer system modelling

Thermo-acoustic performance of green roof substrates in dynamic hygrothermal conditions

Green roofs can be considered as effective and esthetically appreciated passive tools for energy saving systems in buildings. In particular, the effect of evapotranspiration and the large thermal inertia of such solutions, represent highly attractive properties to be implemented in advanced building envelope components. Although these properties are deeply influenced by external factors such as weather conditions, and greenery dynamics, the materials used in substrate and drainage layers are too commonly assumed as constant thermal insulation layers depending only on their physical properties and water content. In particular, common disaggregated materials used in internal layers of extensive green roofs, generally are characterized by a highly complex matrix, and consequently, such materials usually lack of realistic thermal-acoustic properties evaluation. The main objective of the study is to investigate the impact of water content on the thermo-acoustic performance of different disaggregated materials from green roofs substrates commonly used in Mediterranean climates. In particular, the TPS method was used to assess the effect of humidification and raining processes on the final performance of the considered samples. An extensive acoustic characterization was also developed, based on the acoustic transfer function method. Results show that raining processes can highly influence the thermal performance of such materials, which depending on their density, can even triple their thermal conductivity value and achieve twice the volumetric specific heat at ambient conditions. Furthermore, the acoustic characterization procedure showed that the biggest modification on the final acoustic absorption and insulation capability, i.e. about 20 dB when the 80 mm samples, was produced by increasing the water content of the system from 10% to 30% RH. On the contrary, the conditioning at 90% RH does not produce significant differences of the final acoustic behavior of the substrates. Keywords: green roofs, substrates, dynamicAcknowledgments are due to the “CIRIAF program for UNESCO” in the framework of the UNESCO Chair “Water Resources Management and Culture”. The research leading to these results has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No. 657466 (INPATH-TES). The work is also partially funded by COOL CRETE Project, under the framework of Call L. 598/94 Art. 11 – Industrial research and experimental development (Energy sector) supported by Luigi Metelli S.p.A., and by the Spanish governmentENE2015-64117-C5-1-R (MINECO/FEDER) in collaboration with the company Buresinnova S.A (Mercabarna Flor - Local n. 412 Ctra. Antiga de València, 1. 08830 Sant Boi de Llobregat. www.buresinnova.com). The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2017 SGR 1537). GREA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. Julià Coma would like to thank Ministerio de Economia y Competitividad de España for Grant Juan de la Cierva, FJCI-2016-30345

Lettuce Production under Mini-PV Modules Arranged in Patterned Designs

The growing need for clean energy and food production are favoring the use of underused spaces, such as rooftops. This study aims to demonstrate the compatibility of the use of rooftops both for the production of photovoltaic energy and for the production of food, despite the fact that both compete for the same resource, sunlight (rooftop agrivoltaic). In the experiment reported in this study, which was carried out in Almería (Spain) during the spring and summer of 2021, three shade treatments were tested for a lettuce crop, produced by photovoltaic modules with different arrangements: concentrated shade (CS), scattered shade (SS) and full sun (FS). This experiment was repeated in two seasons with high radiation levels and temperature. The results show that in these environmental conditions, the cultivation of plants that demand little sunlight, such as lettuce, is compatible with the shading produced by photovoltaic panels. In addition, it is shown that the same percentage of the area covered with shade (22%), but using mini-PV modules arranged in patterns, improves the productivity (fresh weight, dry matter, number of leaves, maximum length and dry matter of roots) of lettuce cultivation, both in spring and summerinfo:eu-repo/semantics/publishedVersio

A comparison of energy and thermal performance of rooftop greenhouses and green roofs in Mediterranean climate: A hygrothermal assessment in WuFi

In urban areas, a considerable proportion of energy demand is allocated to buildings. Since rooftops constitute one-fourth of all urban surfaces, an increasing amount of attention is paid to achieving the most efficient shapes and component designs compatible with every climate and urban context, for rooftops of varying sizes. In this study, three types of rooftop technologies, namely insulated, green roof, and rooftop greenhouse, are evaluated for energy and thermal performance using computer simulations. Water surface exposure, absorption, and intrusion are the three important factors in the calculation of hygrothermal models that impact energy consumption and building envelope performance; however, a few studies are specifically focused on providing realistic results in multi-dimensional hygrothermal models and the assessment of the impact of moisture in roofing solutions. This paper aims at evaluating the performance of three different roofing technologies through a two-dimensional hygrothermal simulation in software WUFI. To accomplish this, a precise localized microclimate model of a complex urban context on the scale of a neighborhood was employed to evaluate the cooling and heating loads of the buildings, the impact of the water content in the green roof on the thermal behavior of the roof surface, and the feasibility of designing a building with nearly zero cooling needs. A two-story building in the city center of Bologna, Italy is modelled. Simulation results have shown that during the cooling period, the performance of the designed rooftop greenhouse is the most effective by 50% reduction in cooling loads. Besides, the impact of moisture in green roofs has been detected as a negative factor for thermal and energy performance of the building in the Mediterranean climate. The results ultimately highlighted the capability of passively-designed rooftop greenhouses to create a building with nearly zero cooling needs

Resilience of green roofs to climate change

The successful management of cities growth rely in part on the maximization of the benefits delivered by the built environment while minimizing the environmental degradation. Circular and resourceful cites are the mainstream for climate change resilience. Green roofs, as a nature-based solution, contribute to climate change adaptation and mitigation through the provision of several ecosystem services. Value of green roofs can be achieved at the level of environmental (e.g., air quality enhancement, carbon sequestration, biodiversity promotion stormwater management, acoustic insulation, and noise reduction), social (e.g., esthetic integration, well-being and life quality, rooftop gardens), and economic (e.g., life span extension, energetic efficiency, energy production, real-state valorization, business development) spheres. Buildup green roof resilience maybe underpinned by the selection of efficient and sustainable components for its installation. This chapter aims at giving an overview on the role of green roofs resilience to climate change, highlighting the provision of services and the mitigation and adaption capacity.info:eu-repo/semantics/acceptedVersio

Photovoltaic-green roof energy communities can uphold the European Green Deal: Probabilistic cost-benefit analyses help discern economically convenient scenarios

The new roadmap of the European Union (EU), the European Green Deal, aims at tackling climate adaptation, energy, biodiversity, and pollution challenges. To contribute to such aim, the latest EU Renewable Energy Directive defines for the first time renewable energy communities. Among them, Photovoltaic-Green roof Energy Communities (PGECs) emerge as a potential option in urban areas. This paper investigates whether and under which conditions PGECs are capable to meet the objectives of the European Green Deal in an economically convenient manner. Since some conditions are context-specific, this research is showcased using a case study (Luxembourg). First, European legislation was reviewed to determine the suitable legal model for PGECs. Second, a systematic literature review helped identifying lifecycle costs and benefits of photovoltaic-green roofs and their value ranges. Third, a model for probabilistic social and private cost-benefit analyses was developed and tailored to Luxembourg. Lastly, Scenario Discovery was used to identify the ranges of input values leading to desirable net present values. Results show that PGECs can contribute to achieving multiple objectives of the European Green Deal in an economically convenient manner. From the societal perspective, PGECs are found to be economically convenient for any cost, benefit, and discount rate in the case study. From the private perspective, PGECs remain convenient in 62% of the scenarios, with green roofs’ installation cost and electricity generation benefit playing pivotal roles. This paper presents a rare combination of probabilistic cost-benefit analyses and scenario discovery, It supports policymakers designing incentive schemes for PGECs, and can be replicated in other countries

Urban surface uses for climate resilient and sustainable cities: A catalogue of solutions

Abstract In the current scenario of massive urbanization and global climate change, the urban surfaces and their characteristics have a key role, as they significantly influence the quality of life in urban areas, as well as their environmental conditions. To shed light on the role of urban surfaces in fostering climate resilient and sustainable cities, this paper proposes a catalogue of solutions for the urban surface use. The catalogue presents the main surface uses suitable for the built environment, and discusses the potential conflicts and synergies among them in the view of a multiple and integrated utilization of urban surfaces. Reviewing studies published in the last 15 years, this study aims to answer three major questions: (i) which solutions do exist, (ii) where can these be applied, and (iii) which benefits do they provide. The discussion demonstrates that the use of urban surfaces might lead the development of multiple opportunities for improving the existing urban environments and supporting not only environmental, but also social and economic resilience. Finally, it emphasizes the need for specific quantitative and qualitative approaches to address the multi-disciplinary challenges posed by the design and implementation of surface uses, and the evaluation of their contribution to site-specific objectives