1,720,960 research outputs found
Applicazione di cementi fotocatalitici nelle opere di ingegneria civile
No full textNell’ambito della realizzazione di opere di ingegneria civile, quali edifici, reti
stradali in un contesto di tessuto connettivo urbano e non, l’impiego di cementi
fotocatalitici si colloca nel contesto attuale in cui è necessario coniugare
esigenze di valorizzazione del patrimonio esistente e di nuova edificazione con
le problematiche derivanti dall’inquinamento e di durabilità anche estetica.
Attraverso il processo fotocatalitico si è in grado di ridurre le concentrazioni di
inquinanti fotochimici in aria, mantenere le superfici pulite, bianche nonché
attive nella cattura e nello smaltimento di composti sotto forma di sali dilavati.
Di qui la scelta di abbinare alle consuete caratteristiche di impiego di un
cemento tradizionale le proprietà derivanti dal processo ossidativo
fotocatalitico, nel sincretistico approccio dell’impiego di cementi additivati con
TiO2.
Le possibili applicazioni comprendono numerose opere di ingegneria civile. Le
realizzazioni su cui si è indagato hanno coinvolto la messa a punto, dapprima, di
miscele di calcestruzzo drenante con cemento fotocatalitico, con aggregati
naturali e/o riciclati, per pavimentazioni stradali e la realizzazione di provini per
lo studio in laboratorio di fotocatalisi. Si è quindi proceduto a studiare
applicazioni in campo prova di calcestruzzo drenante e calcestruzzo drenante
fotocatalitico, di materiali fotocatalitici, tra cui un rasante e pitture, per
l’applicazione su superfici in ambiente outdoor ed indoor, quali su pareti di una
galleria stradale, di prodotti fotocatalitici per la applicazione a freddo su
pavimentazione, in particolare, di tipo autostradale.
Per quanto concerne la messa a punto delle miscele, il calcestruzzo drenante è
stato oggetto di studio in laboratorio calcestruzzi per il raggiungimento di
adeguate proprietà meccaniche ed idrauliche di permeabilità, nonché sono
state analizzate le proprietà in termini di abbattimento di inquinanti organici ed
inorganici, attraverso prove in modalità plug-flow, seguendo la attuale
normativa italiana aggiungendo tuttavia prove realizzate in modalità batch,
proponendo un modello per la caratterizzazione dei materiali e dei campioni
provenienti da opere realizzate con cementi fotocatalitici attraverso parametri
cinetici e di adsorbimento. Sono stati condotti studi sull’analisi per immagini,
approfondendo le indagini tramite scansioni in 2D e 3D, dimostrandone l’utilità
di impiego.
Relativamente agli studi su grande scala, sono state progettate e verificate
metodologie di lavoro atte a monitorare, isolare, indagare i parametri ritenuti
fondamentali nello studio di applicazioni di questo tipo. Si presentano i risultati
di realizzazioni e monitoraggio relativi ad una pavimentazione realizzata in
calcestruzzo drenante fotocatalitico, rivestimenti per gallerie, applicazione di
prodotti su pavimentazione autostradale
Removal of volatile organic compounds by advanced oxidation process: Performance of a plasma induced oxidation.
No full textPHOTOCHEMICAL POTENTIAL OF TITANIA PAINTING AT A HIGHWAY TUNNEL PORTAL. COMPARISON WITH THE CONDITIONS MEASURED ON SITE
No full textThe aim of this study is to evaluate the photoactivity of a commercial TiO2 coating at a highway tunnel, illuminated by UV-A lamps
Performance of a plasma induced oxidation on the removal of indoor volatile organic compounds
Get PDFThere is much interest in developing new technologies in order to improve indoor air quality. In this study non-thermal plasma (DC negative corona discharge) was explored as an innovative process for indoor air purification. Lab-scale test for Volatile Organic Compounds (VOCs) removal in an enclosed chamber, including a first-stage electrostatic precipitator (ESP) and UVA lamp, were executed for simultaneous removal of gaseous and particulate contaminants. Measurements of the temporal variation of the VOC concentration were employed for evaluating the rate removal. The ozone generation rate was noticeably decreased when the UVA lamp was operating. It is believed that additional studies are needed in the area of ozone enhanced oxidation with the aim to identify reaction products, allowing a better understanding of the degradation pathway of VOC in a non-thermal plasma
Photocatalytic action of water-based TiO2 paint inside a highway tunnel
No full textEuropean Symposium on Photocatalysis. CITE' MONDIALE
BORDEAUX - FRANC
Durability of NO Oxidation Effectiveness of Pavement Surfaces Treated with Photocatalytic Titanium Dioxide
Get PDFNowadays, photocatalysis has demonstrated to be a reliable solution in order to purify the atmosphere from the pollutants originated by vehicular traffic. Owing to the primary importance of this problem, the potential of innovative photocatalytic techniques, dealing with the immobilization of titanium dioxide TiO2 on the surface of the asphalt pavement, has been investigated. In particular, three different products, two bituminous emulsions and a cement mortar, were applied on the right lane and on the emergency lane of a highway section in Italy. The effectiveness of the photocatalytic treatments and its evolution with time were evaluated on cores taken after 1, 17, 46, 88, 218, and 527 days from the application of the products. Two tests were carried out on the cores: The NO degradation was evaluated through continuous flow tests, and the size of the treated areas was quantified by means of digital image analysis methods. The research showed interesting results, as all the techniques, in particular the bituminous emulsion-based products, proved to have a good effectiveness in air de-polluting, even if a decay of performance was noted, depending of traffic and weather conditions
Airborne Pollutant inside a Highway Tunnel Coated with a Photocatalytic Mortar
No full textAir pollution measurements were carried out at the Cavallo highway tunnel in Ancona, Italy. The tunnel is used daily by an average of 20,000 vehicles, of which 25% are gasoline fueled passenger cars, 25% diesel cars, and 50% trucks. Tunnel air concentrations of carbon dioxide, carbon monoxide, volatiles organic compounds (VOC), aromatic hydrocarbons and Nitrogen Oxides (NOx) are presented. An integrated sampling-analysis strategy has been implemented in order to get evidence on photocatalytic processes involved inside a highway tunnel freshly coated with mortar containing photocatalytic TiO2. In situ measurements, rather than laboratory material testing, has offered an efficient way for evaluating the occurrence of photocatalytic reactions, in spite of the presence of many conflicting meteorological and traffic parameters. The CO2 level inside the tunnel after the photocatalytic mortar treatment resulted initially 22% lower than before treatment but it reduced to a 14% within 6 months. The consistent decreases of acetates, nitrites, and sulphates, together with the sensible increase of oxalates observed on carbon adsorbing panels, point to the occurrence of oxidative reactions occurring inside the coated tunnel. Further study is required to elucidate the effect of NOx adsorption, in order to be able to make predictions of the time-dependence on the de-polluting effect, or how the mortar is influenced by the relative humidity, as well as its composition and exposure history
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
