9,014 research outputs found
Characterization of Fibrous Insulating Materials in their Application in Dynamic Insulation Technology
No full textPrevious studies dealing with dynamic insulation technology neglect the microscopic interaction between the solid matrix of
the porous material and the air flowing through the pore structure. The main goal of this work is to investigate this interaction,
and its effects on the heat transfer phenomena at macroscopic scale using the Volume Average Method. At first, the microscopic
geometry of two samples of rock wool is investigated through image analysis, leading to the evaluation of porosity and
granulometry. Then, the volume averaging technique is applied to the microstructure of fibrous materials. Thermal dispersion and
thermal tortuosity are introduced and evaluated through numerical simulations of simplified geometry in laminar and low-Pe
conditions, and two regression equations are defined
The Dual Air Vented Thermal Box: A Laboratory Apparatus to Test Air Permeable Building Envelope Technologies
No full textDynamic insulation technology has been investigated in detail in the context of a research program conducted by the Building
Physic group of the Department of Energy in the Politecnico di Milano. In order to assess the energy performance of this kind of
building envelope, either in steady-state or in dynamic conditions, a specific test apparatus has been designed and built.
It consists of two thermally controlled chambers, separated by a metal frame hosting the air-permeable wall sample, one fed
by a temperature controlled air flow, and the other discharged of the air flowing through the sample. The air flow is realized
through a close air loop between the two chambers. The temperature control is achieved with three parallel water circuits (two for
the boxes, one for the air loop) mixing cold (~11°C) and hot (~60°C) water. This work deals with the description of the whole
apparatus and its measurement and control system, along with the procedure of characterization and calibration of the
temperature control system in steady-state conditions
Studio di fattibilità sulla produzione di energia presso il complesso di edifici storici del Castello di Zena (PC). Parte I: produzione di energia da fonti rinnovabili
No full textIl parco edifici italiano conta al suo interno un gran numero di elementi di pregio storico. Il contenimento dei consumi energetici a livello nazionale passa necessariamente dalla riqualificazione di tale tipologia di fabbricati, anche mediante un uso oculato delle tecnologie impiantistiche attualmente disponibili.
Nel quadro dell’attività di studio e ricerca sul tema del recupero funzionale degli edifici storici (progetto S.O.C.R.A.T.E.S.), ci si è occupati dello studio di fattibilità sulla produzione di energia termica ed elettrica a partire principalmente da fonti rinnovabili presso il complesso del Castello di Zena, situano nel comune di Carpaneto Piacentino (PC).
L’analisi è partita dalla raccolta dei dati relativi agli edifici oggetto di studio (caratteristiche fisiche e geometriche delle soluzioni tecniche d’involucro e di partizione interna, destinazioni d’uso), immediatamente seguita dalla loro modellazione
numerica finalizzata alla simulazione del comportamento energetico in regime dinamico.
In seguito all’individuazione delle curve di carico termiche, frigorifere ed elettriche, sono state prese in esame alcune configurazioni impiantistiche che combinano in vario modo le seguenti tecnologie: cogenerazione, trigenerazione, solare termico, pannelli fotovoltaici, caldaie a biomassa e pompe di calore a ciclo invertibile a emungimento d’acqua di falda.
Sono state effettuate valutazioni di carattere economico e ambientale, volte a definire la migliore soluzione impiantistica, tra quelle proposte, in termini di rapporto costi/benefici.
Lo scopo di questo articolo è di descrivere gli edifici oggetto di analisi, le tipologie impiantistiche esaminate (con esclusione di quelle cogenerative e trigenerative, la cui trattazione è rimandata alla Parte II del presente articolo), le fasi degli studi svolti relativamente alle configurazioni con implementazione di impianti per lo sfruttamento dell’energia solare e, infine, riportare i risultati del progetto
Analytical modelling of Breathing Walls: experimental verification by means of the Dual Air Vented Thermal Box lab facility
No full textBreathing Walls are air permeable envelope components based on porous materials. In contra-flux operation air flows opposite to
conductive flux, while in pro-flux they have the same direction. The Breathing Wall behaves either as a ventilation heat exchanger
or as an active insulation.
In literature an analytical model describing steady state heat transfer across a Breathing Wall can be found. Since it lacks an
exhaustive experimental validation, a facility developed at the Energy Department of Politecnico of Milano was used to investigate
the thermo-physical behavior of a no-fines concrete based Breathing Wall in steady state Dirichlet conditions and contra-flux
operation
Reply to: Comment on "Repeated HyperArc radiosurgery for recurrent intracranial metastases and dosimetric analysis of recurrence pattern to account for diffuse dose effect on microscopical disease"
No full textEffect of pasteurization on in vitro α-glucosidase inhibitory activity of apple juice
No full textThe in vitro alpha-glucosidase inhibitory activity of raw, mildly (F-71.7(5) = 0.4 min, 5 Log reductions of Cryptosporidium parvum) and intensively (F-90(12) = 14.8 min, 2 Log reductions of Alicyclobacillus acidoterrestris) pasteurized apple juice was studied. Raw apple juice (23 mg(dw)/mL) caused 90% alpha-glucosidase inhibition. Analogous results were obtained for the mildly treated sample. The most intense treatment reduced by 35% the alpha-glucosidase inhibition. However, such a decrease was associated with an increase in the phenolic content, suggesting that alpha-glucosidase inhibition might not rely on these compounds, but depend on more complex mechanisms. Apple juice was combined with acarbose to investigate their interaction towards alpha-glucosidase inhibition. A synergistic behavior was observed for concentrations < 2 mg/mL. Increasing the concentration of the combined system (up to 9 mg/mL) produced an antagonistic effect, while a further increase (< 9 mg/mL) allowed approaching an addictive behavior
Experimental investigation of the steady state behaviour of Breathing Walls by means of a novel laboratory apparatus
No full textBreathing Walls are envelope components, based on porous materials, crossed by a natural or forced airflow. Since they behave both as recovery heat exchangers and active insulation, reducing the conductive heat flux, they represent a promising envelope technology, allowing to reduce energy consumption in buildings. From the modeling point of view, an analytical model can be found in literature, describing heat and mass transfer across Breathing Walls in steady state conditions. However, to the best of the authors' knowledge, the model lacks an exhaustive experimental validation. Therefore, in this paper, the novel laboratory apparatus named Dual Air Vented Thermal Box developed at Politecnico of Milano is presented. The apparatus is used to experimentally investigate the steady state behaviour of a 1 m2 Air Permeable Concrete sample, crossed by an airflow at different velocities up to 12 mm/s. The temperature profile inside the sample, measured in different positions, is compared with the model predictions. While in the central portion of the wall a very good agreement is found, the experimental results at the top and at the bottom of the wall suggest a non-uniform velocity field entering the sample. A qualitative confirmation of this hypothesis is provided by CFD simulations on the apparatus, clearly showing a mixed convection regime on both sides of the wall. The results lead to state the validity of the one-dimensional analytical model in literature, although a careful application should take into account adjusted boundary conditions, consisting in an airflow velocity possibly variable with height
La proiezione europea della nobiltà bolognese nel XVI secolo
No full textil lavoro indaga i modi in cui la nobiltà bolognese del XVI secolo stringe contatti col resto dell'Europa: presenze di stranieri in città, insegnamento all'estero, pellegrinaggi, servizio diplomatico, attività commerciali, emigrazione per motivi di dissenso religioso, carriere militari; si esaminano poi i legami clientelari che alcune famiglie stringono con le corti di Asburgo, Valois, Tudor e altri sovrani e il rafforzamento progressivo del servizio al Papa come via per ottenere contatti internazionali ed emergere nella società local
Andrea Bacová
No full textAndrea Bacová focuses on research and teaching in the field of residential architecture. Her work includes systematic research on residential buildings and their urban context. She actively participates in promoting Slovak architecture and is the author of several publications and exhibitions
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