164 research outputs found

    Valutazione del comportamento energetico dell'architettura storica. Analisi del metodo di calcolo dello stato di fatto energetico e proposte correttive.

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    A project of energetic redevelopment of a historic building starts from the preliminary assessment of its energy potential and residual performance, in order to tailor interventions and properly address the energy needs according to the characteristics of the building, without losing or jeopardizing its heritage and historic value. This approach is relatively new and specific industry regulations have not yet been developed. The absence of specific legislation means that a dedicated methodology for calculating the energy performance of historic buildings is not included in the best practices of intervention. Currently the energy performance of historic buildings, on which the whole intervention project is based, is calculated with the same tools developed for modern buildings. This research starts from the hypothesis that the two types of calculation available today (analytical standardized method and simplified method) present some limits of applicability, in particular if used for the evaluation of historical architecture, which has technical, geometric, and architectural characteristics that differ significantly from the ones of newer buildings. The use of non-specific instruments can lead to errors in the calculation of the residual energetic performance of buildings. This calculation error can consequently lead to choices of intervention that can be harmful to the conservation of the building, to final level of comfort of its interior, or to its resulting energy efficiency. This study, therefore, critically analyzes the current methods of calculating energy efficiency, with the aim of verifying their validity and limits of applicability by testing them on a sample of historic buildings. This analysis shows significant differences between the results obtained by the analytical method, taken as reference, and the calculations made with the simplified system. It identifies the need for evaluating the energy performance of historic architecture in a different way from that used for recent buildings. At the same time, the application of different methods of calculation to the case studies also highlights the inherent difficulty of finding, for buildings constructed in the past, the necessary data for correctly applying the standard analytical method, regarded so far as the only reliable system. These findings call for the refinement of the simplified method, more suitable to the calculation of the energy performance of historic buildings, and the development of a new instrumental method for the measurement of the energy characteristics of historic buildings, which can be used in parallel with the analytical calculation

    Geomorphic signal of active faulting at the northern edge of Lut Block. Insights on the kinematic scenario of Central Iran

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    Recent works documented Neogene to Quaternary dextral strike-slip tectonics along the Kuh-e-Sarhangi and Kuh-e-Faghan intraplate strike-slip faults at the northern edge of the Lut Block of Central Iran, previously thought to be dominated by sinistral strike-slip deformation. This work focuses on the evidence of Quaternary activity of one of these fault systems, in order to provide new spatio-temporal constraints on their role in the active regional kinematic scenario. Through geomorphological and structural investigation, integrated with Optically Stimulated Luminescence (OSL) dating of three generations of alluvial fans and fluvial terraces (at ~53, ~25 and ~6 ka), this study documents (i) the topographic inheritance of the long-term (Myr) punctuated history of fault nucleation, propagation, and exhumation along the northern edge of Lut Block; (ii) the tectonic control on drainage network evolution, pediment formation, fluvial terraces, and alluvial-fan architecture; (iii) the minimum Holocene age of Quaternary dextral strike-slip faulting; and (iv) the evidence of Late Quaternary fault-related uplift localized along the different fault strands. The documented spatial and temporal constraints on the active dextral strike-slip tectonics at the northern edge of Lut Block provided new insights on the kinematic model for active faulting in Central Iran, which has been reinterpreted in an escape tectonic scenario

    From the Dynamic Simulations Assessment of the Hygrothermal Behavior of Internal Insulation Systems for Historic Buildings towards the HeLLo Project

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    In the context of functional and performance rehabilitation of existing heritage, internal envelope thermal insulation is often an inevitable option towards improvement of historic buildings’ energy efficiency. Nonetheless, besides leading to the loss of useful floor area, this option may also lead to changes on the original hygrothermal behavior of such walls. Applied to a real case study, this paper presents the dynamic simulations assessment of a few thermal retrofitting materials, unveiling the significance of the proper choice of the materials in the software’s’ library (aiming at avoiding biased results) as well as reinforcing the importance of real in situ measurement for validation of such estimations, e.g. the HeLLo project

    Two timber construction models: tradition without innovation or innovation without tradition?

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    This paper evaluates the influence of timber construction on architectural design through a critical analysis and comparison between two environmental and building contexts that are culturally and geographically different from one another:  the experience of the former British colonies, represented by New Zealand, and the Mediterranean one, described by Italy. This comparison moves through the investigation on three themes: the cultural value of the construction process; the performance realm (environmental, energy and seismic ones as firsts); the design dimension. The contribution underlines divergences and similarities of the technological culture of design in two countries that share similar requirements regarding post-earthquake reconstruction

    Design and Construction of a New Metering Hot Box for the In Situ Hygrothermal Measurement in Dynamic Conditions of Historic Masonries

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    The main purpose of the HeLLo project is to contribute to data available on the literature on the real hygrothermal behavior of historic walls and the suitability of insulation technologies. Furthermore, it also aims at minimizing the energy simulation errors at the design phase and at improving their conservation features. In this framework, one of the preliminary activities of the study is the creation of a real in situ hot box to measure and analyze different insulation technologies applied to a real historic wall, to quantify the hygrothermal performance of a masonry building. Inside this box, ‘traditional’ experiments can be carried out: recording heat flux, surface temperature, and air temperatures, as well as relative humidity values through the use of a new sensing system (composed of thermocouples and temperature/relative humidity combined sensors). Within this paper, the process of development, construction, and validation of this new metering box is exhibited. The new hot box, specifically studied for historic case studies, when compared to other boxes, presents other advantages compared to previous examples, widely exemplified

    Applied Research of the Hygrothermal Behaviour of an Internally Insulated Historic Wall without Vapour Barrier: In Situ Measurements and Dynamic Simulations

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    The hygrothermal behaviour of an internally insulated historic wall is still hard to predict, mainly because the physical characteristics of the materials composing the historic wall are unknown. In this study, the hygrothermal assessment of an internally thermal insulated masonry wall of an historic palace located in Ferrara, in Italy, is shown. In situ non-destructive monitoring method is combined with a hygrothermal simulation tool, aiming to better analyse and discuss future refurbishment scenarios. In this context, the original U-value of the wall (not refurbished) is decreased from 1.44 W/m2K to 0.26 W/m2K (10 cm stone wool). Under the site specific conditions of this wall, not reached by the sun or rain, it was verified that even in the absence of vapour barrier, no frost damage is likely to occur and the condensation risk is very limited. Authors proposed further discussion based on simulation. The results showed that the introduction of a second gypsum board to the studied technology compensated such absence, while the reduction of the insulation material thickness provides a reduction of RH peaks in the interstitial area by 1%; this second solution proved to be more efficient, providing a 3% RH reduction and the avoidance of further thermal losses

    Applied Research of the Hygrothermal Behaviour of an Internally Insulated Historic Wall without Vapour Barrier: In Situ Measurements and Dynamic Simulations

    Get PDF
    The hygrothermal behaviour of an internally insulated historic wall is still hard to predict, mainly because the physical characteristics of the materials composing the historic wall are unknown. In this study, the hygrothermal assessment of an internally thermal insulated masonry wall of an historic palace located in Ferrara, in Italy, is shown. In situ non-destructive monitoring method is combined with a hygrothermal simulation tool, aiming to better analyse and discuss future refurbishment scenarios. In this context, the original U-value of the wall (not refurbished) is decreased from 1.44 W/m2K to 0.26 W/m2K (10 cm stone wool). Under the site specific conditions of this wall, not reached by the sun or rain, it was verified that even in the absence of vapour barrier, no frost damage is likely to occur and the condensation risk is very limited. Authors proposed further discussion based on simulation. The results showed that the introduction of a second gypsum board to the studied technology compensated such absence, while the reduction of the insulation material thickness provides a reduction of RH peaks in the interstitial area by 1%; this second solution proved to be more efficient, providing a 3% RH reduction and the avoidance of further thermal losses

    Spatio-temporal evolution of intraplate strike-slip faulting: the Neogene-Quaternary Kuh-e-Faghan Fault, Central Iran

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    Central Iran provides an ideal region to study the long-term morphotectonic response to the nucleation and propagation of intraplate faulting. In this study, a multidisciplinary approach that integrates structural and stratigraphic field investigations with apatite (U+Th)/He (AHe) thermochronometry is used to reconstruct the spatio-temporal evolution of the Kuh-e-Faghan Fault (KFF) in northeastern Central Iran. The KFF is a narrow, ca. 80 km long, deformation zone that consists of three main broadly left stepping, E-W trending, dextral fault strands that cut through the Mesozoic-Paleozoic substratum and the Neogene-Quaternary sedimentary cover. The AHe thermochronometry results indicate that the intra-fault blocks along the KFF experienced two major episodes of fault-related exhumation at ~18 Ma and ~4 Ma. The ~18 Ma faulting/exhumation episode is chiefly recorded by the structure and depositional architecture of the Neogene deposits along the KFF. A source-to-sink scenario can be reconstructed for this time frame, where topographic growth caused the synchronous erosion/exhumation of the pre-Neogene units and deposition of the eroded material in the surrounding fault-bounded continental depocenters. Successively, the KFF gradually entered a period of relative tectonic quiescence and, probably, of regional subsidence during which a thick pile of fine-grained onlapping sediments were deposited. This may have caused resetting of the He ages of apatite in the pre-Neogene and the basal Neogene successions. The ~4 Ma faulting episode caused the final exhumation of the fault system, resulting in the current fault zone and topography. The two fault-related exhumation episodes fit with the regional early Miocene collision-enhanced uplift/exhumation, and the late Miocene–early Pliocene widespread tectonic reorganization of the Iranian plateau. The reconstructed long term, spatially and temporally punctuated fault system evolution in intraplate Central Iran during Neogene-Quaternary times may reflect states of far-field stress changes at the collisional boundaries

    Salinomycin potentiates the cytotoxic effects of TRAIL on glioblastoma cell lines

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    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to exhibit therapeutic activity in cancer. However, many tumors remain resistant to treatment with TRAIL. Therefore, small molecules that potentiate the cytotoxic effects of TRAIL could be used for combinatorial therapy. Here we found that the ionophore antibiotic salinomycin acts in synergism with TRAIL, enhancing TRAIL-induced apoptosis in glioma cells. Treatment with low doses of salinomycin in combination with TRAIL augmented the activation of caspase-3 and increased TRAIL-R2 cell surface expression. TRAIL-R2 upmodulation was required for mediating the stimulatory effect of salinomycin on TRAIL-mediated apoptosis, since it was abrogated by siRNA-mediated TRAIL-R2 knockdown. Salinomycin in synergism with TRAIL exerts a marked anti-tumor effect in nude mice xenografted with human glioblastoma cells. Our results suggest that the combination of TRAIL and salinomycin may be a useful tool to overcome TRAIL resistance in glioma cells and may represent a potential drug for treatment of these tumors. Importantly, salinomycin+TRAIL were able to induce cell death of well-defined glioblastoma stem-like lines

    PDGF-B-driven gliomagenesis can occur in the absence of the proteoglycan NG2

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    <p>Abstract</p> <p>Background</p> <p>In the last years, the transmembrane proteoglycan NG2 has gained interest as a therapeutic target for the treatment of diverse tumor types, including gliomas, because increases of its expression correlate with dismal prognosis. NG2 has been shown to function as a co-receptor for PDGF ligands whose aberrant expression is common in gliomas. We have recently generated a glioma model based on the overexpression of PDGF-B in neural progenitors and here we investigated the possible relevance of NG2 during PDGF-driven gliomagenesis.</p> <p>Methods</p> <p>The survival curves of NG2-KO mice overexpressing PDGF-B were compared to controls by using a Log-rank test. The characteristics of tumors induced in NG2-KO were compared to those of tumors induced in wild type mice by immunostaining for different cell lineage markers and by transplantation assays in adult mice.</p> <p>Results</p> <p>We showed that the lack of NG2 does not appreciably affect any of the characterized steps of PDGF-driven brain tumorigenesis, such as oligodendrocyte progenitor cells (OPC) induction, the recruitment of bystander OPCs and the progression to full malignancy, which take place as in wild type animals.</p> <p>Conclusions</p> <p>Our analysis, using both NG2-KO mice and a miRNA based silencing approach, clearly demonstrates that NG2 is not required for PDGF-B to efficiently induce and maintain gliomas from neural progenitors. On the basis of the data obtained, we therefore suggest that the role of NG2 as a target molecule for glioma treatment should be carefully reconsidered.</p
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