Energy refurbishment planning of Italian school buildings using data-driven predictive models

In the current practice, the design of energy refurbishment interventions for existing buildings is typically addressed by performing time-consuming software-based numerical simulations. However, this approach may be not suitable for preliminary assessment studies, especially when large building portfolios are involved. Therefore, this research work aims at developing simplified data-driven predictive models to estimate the energy consumption of existing school buildings in Italy and support the decision-making process in energy refurbishment intervention planning at a large scale. To accomplish this, an extensive database is assembled through comprehensive on-site surveys of school buildings in Southern Italy. For each school, a Building Information Modelling (BIM) model is developed and validated considering real energy consumption data. These BIM models serve in the design of suitable energy refurbishment interventions. Moreover, a comprehensive parametric investigation based on refined energy analyses is carried out to significantly improve and integrate the dataset. To derive the predictive models, firstly the most relevant parameters for energy consumption are identified by performing sensitivity analyses. Based on these findings, predictive models are generated through a multiple linear regression method. The suggested models provide an estimation of the energy consumption of the “as-built” configuration, as well as the costs and benefits of alternative energy refurbishment scenarios. The reliability of the proposed simplified relationships is substantiated through a statistical analysis of the main error indices. Results highlight that the building's shape factor (i.e., the ratio between the building's envelope area and its volume) and the area-weighted average of the thermal properties of the building envelope significantly affect both the energy consumption of school buildings and the achievable savings through retrofitting interventions. Finally, a framework for the preliminary design of energy refurbishment of buildings, based on the implementation of the herein developed predictive model, is proposed and illustrated through a worked example application. Worth noting that, while the proposed approach is currently limited to school buildings, the methodology can conceptually be extended to any building typology, provided that suitable data on energy consumption are available

Modelling strategies for the numerical simulation of the behaviour of corroded rc columns under cyclic loads

Rebars corrosion phenomena can modify the structural behaviour of reinforced concrete (RC) members and consequently the seismic performance of RC structures. Since many existing RC structures are affected by this phenomenon, the influence of the reinforcement corrosion on the seismic performance is still under examination, especially when the corrosive attack is localized in the dissipative areas of the plastic hinges. In this work, the effect of localized corrosion is numerically investigated, through the adoption of a suitable finite element model, object of validation with the outcomes of an experimental campaign carried out in the Laboratory of the University of Rome “Tor Vergata”, on un‐corroded and corroded RC columns subjected to axial load and cyclic horizontal actions. Particular attention has been paid to the definition of the three-dimensional model and to the modelling of the corroded rebars and their corrosion morphology. Indeed, different modelling strategies are proposed with the aim to properly simulate the cyclic behaviour of the corroded columns. The main results show how more refined strategies taking into account the morphological aspects of the corrosion phenomenon produce a better fit with the experimental results for both Damage Control and Life Safety limit states performance

Experimental evaluation of the corrosion influence on the structural response of Gerber half-joints

The assessment of the Gerber half-joints (or saddles), widespread in the infrastructure heritage of different countries, is nowadays a topical problem since they are often affected by chloride corrosion phenomena due to their positioning under the deck joint. In this paper, the influence of steel rebar corrosion on the experimental response of Gerber half-joints is experimentally analysed and discussed. In particular, four elements were cast in Laboratory of University of Rome “Tor Vergata” two of which subjected to accelerated corrosion, and then tested up to failure. The specimens were designed with typical strut and tie models, with the aim of achieving different failure modes governed by the concrete crush or by the tensile rebar breaking. Particular care was devoted to the corrosion process, in order to simulate decay scenarios typical of these structures. The experimental outcomes, expressed in terms of load–displacement curves, crack patterns and failure mechanisms show that also medium-slight degree of pitting corrosion can cause great reductions in capacity and ductility of the saddles, modifying, in addition, their failure mechanism. Finally, from the experimental outcomes, the sensitivity of these peculiar structures, not only to the corrosion amount, but also to its spatial distribution among the different steel rebars, and its morphology (pitting or uniform corrosion) is clearly underlined. As a consequence, the necessity to accurately and properly account for the corrosion phenomenon in the structural assessment is remarked

Assessing life-cycle seismic fragility of corroding reinforced concrete bridges through dynamic Bayesian networks

Bridge structures are exposed to several chronic and abrupt stressors, among which the combined effects of corrosion and earthquakes pose a major threat to their long-term safety. Probabilistic risk assessment frameworks that quantify and propagate uncertainties inherent to these phenomena are necessary to mitigate this threat. This paper proposes a dynamic Bayesian network for state-dependent seismic fragility functions, capturing corrosion and seismic effects over time. Markovian transitions among deterioration states for different bridge components are developed, combining chloride diffusion and corrosion propagation models with non-stationary Gamma processes. State-dependent fragility curves are derived based on non-linear dynamic time-history analyses given possible degradation configurations of the structure, accounting for uncertainties in material, geometry, and deterioration parameters. Record-to-record variability is captured using synthetic ground motions. Results on a 4-span Gerber bridge showcase the suitability of the framework for describing life-cycle fragility, and its capacity for embedding in advanced algorithmic decision-making workflows is discussed.Architectural Technolog

Effects of the administration of miconazole by different routes on the biomarkers of the "steroidal module" of the Athlete Biological Passport.

This article reports the results obtained from the investigation of the influence of miconazole administration on the physiological fluctuation of the markers of the steroid profile included in the "steroidal module" of the Athlete Biological Passport. Urines collected from male Caucasian subjects before, during, and after either systemic (i.e., oral and buccal) or topical (i.e., dermal) treatment with miconazole were analyzed according to validated procedures based on gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) (to determine the markers of the steroid profile) or liquid chromatography coupled to MS/MS (LC-MS/MS) (to determine miconazole urinary levels). The results indicate that only after systemic administration, the markers of the steroid profile were significantly altered. After oral and buccal administration, we have registered (i) a significant increase of the 5α-androstane-3α,17β-diol/5β-androstane-3α,17β-diol ratio and (ii) a significant decrease of the concentration of androsterone, etiocholanolone, 5β-androstane-3α,17β-diol, and 5α-androstane-3α,17β-diol and of the androsterone/etiocholanolone, androsterone/testosterone, and 5α-androstane-3α,17β-diol/epitestosterone ratios. Limited effects were instead measured after dermal intake. Indeed, the levels of miconazole after systemic administration were in the range of 0.1-12.5 μg/ml, whereas after dermal administration were below the limit of quantification (50 ng/ml). Significant alteration started to be registered at concentrations of miconazole higher than 0.5 μg/ml. These findings were primarily explained by the ability of miconazole in altering the kinetic/efficacy of deglucuronidation of the endogenous steroids by the enzyme β-glucuronidase during the sample preparation process. The increase of both incubation time and amount of β-glucuronidase was demonstrated to be effective countermeasures in the presence of miconazole to reduce the risk of uncorrected interpretation of the results

Detection of 5α-reductase inhibitors by UPLC–MS/MS: Application to the definition of the excretion profile of dutasteride in urine

An analytical procedure based on ultra-performance liquid chromatography-mass spectrometry was developed to screen and to confirm dutasteride and its metabolites in human urine. Sample preparation included an enzymatic hydrolysis followed by solid-phase extraction using the strong cation exchange cartridges OASIS® MCX. The chromatographic separation was carried out on C18 column, employing as mobile phases ultra purified water and acetonitrile, both containing 0.1% formic acid. Detection was achieved using a triple quadrupole as a mass spectrometric analyzer, with positive ion electrospray ionization and multiple reaction monitoring as acquisition mode. The analytical procedure developed was validated according to ISO 17025 and World Anti-Doping Agency guidelines. The extraction efficiency was estimated to be greater than 75% for both dutasteride and its hydroxylated metabolites. Detection capability was determined in the range of 0.1–0.4 ng/mL. Specificity and repeatability of the relative retention times (CV% < 0.5) and of the relative abundances of the characteristic ion transitions selected (CV% < 10) were confirmed to be fit for purpose to ensure the unambiguous identification of dutasteride and its metabolites in human urine. The developed method was used to characterize the urinary excretion profile of dutasteride after both chronic and acute administration of therapeutic doses. After chronic administration, dutasteride and its hydroxylated metabolites were easily detected and confirmed. After acute administration, instead, only the two hydroxylated metabolites were detected for 3–4 days

Application of solid-phase microextraction to antidoping analysis: Determination of stimulants, narcotics, and other classes of substances excreted free in urine

This paper describes the application of solid-phase microextraction (SPME) with subsequent injection in a gas chromatograph\u2013mass spectrometer (GC\u2013MS) (electron impact, full scan) for the screening analysis of stimulants and narcotics in urine. Several d i fferent kinds of fibers were preliminarily tested and comparatively evaluated considering the influence on the overall analytical performance of the method; other experimental parameters; and, primarily among them, the volume of urine, the pH value, and the time of adsorbtion. The optimal experimental conditions have been recorded using 0.5 mL of urine with the pH value adjusted to 10 with carbonate buffer, and in which is immersed a polydimethylsiloxane/divinylbenzene fiber, with a sampling time of 30 min; the fiber is then directly desorbed in the injection port of the GC\u2013MS equipment. All the analytes show a good linearity (R2 > 0.99 for most substances) and a good reproducibility at the concentration corresponding to the minimum performance requirement limit or at the cut-off value fixed by the World AntiDoping Agency (CV% < 11). The limit of detection of the method is 50 ng/mL for the majority of the substances investigated. Imidazole-based drugs (e.g., naphazoline) and local anesthetics can also be included in this screening method. Whenever necessary, confirmation analyses may also be performed by following the same pre-chromatographic procedure. Integrating the SPME process and the GC\u2013MS analysis with a dedicated autosampler that combines the microextraction and injection capacities maximizes the overall analytical capacity of a single GC\u2013MS system and reduces the human labor necessary for and the environmental impact of screening for stimulants and narcotics excreted free in urine