365 research outputs found
The effect of urban obstructions in Mediterranean climates: built form typology, density and energy
No full textIn spite of the ever increasing unsustainable nature of the “conventional” city and its concurrent assertion as a human habitat par excellence, it is important to define intervention strategies that can improve the “metabolic” operation of built environments. If related to urban morphology, these take on more effective potentiality and are a guiding tool for more appropriate, more beneficial interventions. In the specific context of the Mediterranean compact city, the interaction between density, morphology and energy discussed here is one of the components required if not for the complex solution of the problem, then at least for reducing the environmental impact of urban models. The results here proposed of a comparative study carried out on various fabrics in the city of Barcelona, in search of parametric relations between density and energy-environmental behaviour. The said relations, we analyse the effects of urban obstructions: the basis of knowledge required for conscious built environment transformation, towards more efficient conditions
Phenotype description of a novel DFNA9/COCH mutation, I109T.
No full textItem does not contain fulltextOBJECTIVES: This is a report of the audiological and vestibular characteristics of a Dutch DFNA9 family with a novel mutation, I109T, in the LCCL domain of COCH. METHODS: From the family with the novel I109T COCH mutation, audiometric data were collected and analyzed longitudinally. Results were compared to those obtained in previously identified P51 S, G88E, and G87W COCH mutation carriers. Special attention was also given to a comparison of age-related features such as progressive hearing loss and vestibular impairment. RESULTS: A novel mutation (I109T) in COCH segregates with hearing impairment and vestibular dysfunction in the present family. Pure tone thresholds, phoneme recognition scores, and vestibular responses of the I109T mutation carriers were essentially similar to those previously established in P51S, G87W, and G88E mutation carriers. Deterioration of hearing in the I109T mutation carriers started at 43 years of age, and vestibular function deteriorated at least 7 years later. CONCLUSIONS: The phenotype associated with the novel COCH (I109T) mutation is largely similar to that associated with P51S and G88E mutation carriers. However, subtle differences in terms of onset age and rate of progression seem to exist
Which climate for each urban context? A preliminary comparative study on urban climate prediction and measurement in different districts in Rome and Barcelona
No full textThe research progress in building energy modeling and simulation has led to the widespread diffusion of more and more sophisticated software. By contrast, there aren't such effective results when it comes to the urban-scale climate modeling, whose geometric, morphological, material and anthropogenic features clearly distinguishes it from a rural context. The clearest effect of these differences is the Heat Island phenomenon.
Despite that, the weather files currently used for energy simulations practice refer to measurements gauged in out-of-town weather stations, as like airports, causing the results to be unreliable and inaccurate.
The aim of this study is to prove that, despite referring to the same region, latitude or city, quite different microclimates may occur depending on urban local features. To this purpose, temperature data available in urban weather stations located in Rome and Barcelona are inspected and compared to the rural reference station, in order to evaluate the difference of Heat Island intensity in different urban context. The experimental verification is then used to evaluate a recently developed method for generating urban weather files from a rural station, the Urban Weather Generator (UWG). The experimental verification shows a maximum intensity of Urban heat island in Barcelona in July, with a Dt of 4.7° C at 18:00 local time. In the case of Rome there is a maximum Dt of 5° C in August at 17:00 local time. The comparison between measured data and calculate data show that the reliability of the UWG calculation strongly depends on the location of the urban site within the city and on its features. The temperature discrepancies decrease when the urban site is located in a fairly central position and in a rather homogeneous urban fabric. There is a systematic error during the central hours of the day which suggests an underestimation of the effect of radiation and radiative trapping
Vertical corneal striae in families with autosomal dominant hearing loss: DFNA9/COCH.
No full textContains fulltext :
53024.pdf (Publisher’s version ) (Closed access)PURPOSE: Investigation of a possible association between vertical corneal striae and mutations in the COCH gene, observed in four DFNA9 families with autosomal dominant hearing loss and vestibular dysfunction. DESIGN: Prospective case series. METHODS: Ophthalmologic examinations with photography of the cornea after instillation of fluorescein were performed in 98 family members with 61 mutation carriers of four DFNA9 families at the Radboud University Nijmegen Medical Centre. Families 1 and 2 harbor the Pro51Ser mutation, and families 3 and 4 harbor the Gly88Glu and the Gly87Trp mutation, respectively. Statistical analysis was performed to find an association between the vertical corneal striae and the COCH mutation for each family and to test whether the four families were different in this respect. RESULTS: The vertical corneal striae were exclusively visible after instillation of fluorescein. They caused minor problems, as dry eye symptoms, and were not present in the general Dutch ophthalmologic population. The striae were present from an age of 47 years in 32 individuals, of whom 27 individuals had a COCH mutation. Statistical analysis on the striae and the COCH mutations showed a significant association in families 1, 2, and 3 (P = .0006), but not in family 4 (P = .63). CONCLUSIONS: Data analysis demonstrated a significant association between vertical corneal striae and the Pro51Ser and Gly88Glu mutations in the COCH gene in DFNA9 families 1, 2, and 3 with cochleovestibular dysfunction. Our findings suggest that the vertical corneal striae and cochleovestibular dysfunction may be caused by the same COCH mutations
Resilienza urbana ai disastri. Il ruolo del patrimonio costruito. Urban disaster resilience. The role of the built heritage
No full textIl concetto di Resilienza, inizialmente introdotto nella letteratura scientifica in ambito ecologico come un modo per comprendere le dinamiche non lineari osservate negli ecosistemi, si è evoluto seguendo percorsi generalmente indipendenti in varie discipline ed è ad oggi strettamente legato al Disaster Risk Reduction (DRR).
L’impatto di disastri naturali e tecnologici risulta potenzialmente maggiore sulle aree urbane, dove l’elevata densità abitativa incrementa la gravità delle ripercussioni socio-economiche dovute all’interruzione dei servizi essenziali. Nel contesto delle città occorre pertanto potenziare le caratteristiche di resilienza, in modo da incrementare le capacità del sistema di assorbire i disturbi e di cambiare, riorganizzare e conservare le strutture di base ed i servizi essenziali a fronte di eventi calamitosi. Il settore delle costruzioni è tradizionalmente associato alle fasi di ricostruzione. Tuttavia, ad oggi vi è una crescente consapevolezza di come i diversi professionisti operanti sull’ambiente costruito abbiano un ruolo cruciale anche nell’anticipare, valutare e preparare la reazione e il recupero post disastro.
Il patrimonio costruito riveste infatti un ruolo sempre più importante nella definizione e nell’incremento della resilienza urbana ai disastri. In particolare, le città storiche italiane rappresentano un significativo esempio di organismo urbano capace di evolversi ed adattarsi agli eventi sismici che hanno caratterizzato la storia del paese.
Il lavoro di ricerca si concentra sulla definizione del ruolo del patrimonio costruito nella costituzione della resilienza urbana, analizzando la stretta correlazione tra tecnica costruttiva muraria, morfologia e vulnerabilità sismica del costruito storico nel sistema urbano. L’obiettivo della ricerca è quello di costruire indirizzi e strategie per integrare il concetto di resilienza urbana nella logica quotidiana della gestione del territorio, che ormai deve affrontare le tematiche di rischio e sicurezza come dato di input fondamentale, superando i limiti degli specialismi chiamati in causa a fronte di danni ormai manifesti.
In particolare, l’approccio proposto è mirato ad integrare la fase di pianificazione preventiva, dimostrando che è possibile avviare ex-ante opportuni processi di conoscenza e analisi sull’ambiente costruito, utili a fronteggiare quello che viene definito “rischio residuale” e ad indirizzare le scelte decisionali e progettuali dei professionisti coinvolti nella ricostruzione post-disastro.
Dall’analisi delle ricostruzioni dell’ultimo secolo in Italia e dei piani di ricostruzione finora elaborati è possibile identificare alcuni elementi fondamentali che costituiscono una base conoscitiva condivisa su cui strutturare la pianificazione preventiva.
L’insediamento urbano è vulnerabile in quanto sistema, pertanto vi è bisogno di un approccio multiscalare per definire strategie e indirizzi da seguire nelle fasi denominate convenzionalmente prevenzione e ricostruzione. Da questo punto di vista, pianificare include stabilire un ordine di priorità col quale si svolgeranno le attività. Attraverso l’analisi su casi studio di centri storici italiani, la metodologia proposta individua strategie di preparazione alla crisi mettendo a sistema il dato materiale del costruito (analisi di vulnerabilità, caratteri del costruito e fasi evolutive degli aggregati), con analisi di tipo urbanistico/sistemico, attraverso un approccio matriciale volto all’individuazione di priorità di intervento nella città storica. I casi studio scelti sono le città storiche di Rieti (Lazio) e San Gemini (TR – Umbria, entrambe collocate in una zona con pericolosità sismica medio alta (zona 2) e rappresentative di una percentuale significativa dei comuni italiani in quanto a dimensione e popolazione insediata.
I risultati della ricerca evidenziano come i caratteri morfologici dei tessuti urbani ed i caratteri di aggregazione assumano una rilevanza sulle prestazioni del costruito, e come in un’ottica di gestione del territorio tali apporti vadano approfonditi ed integrati nelle attuali valutazioni della vulnerabilità sismica. L’analisi sul dato materiale del patrimonio costruito ha permesso di evidenziare e comprendere il rapporto esistente tra le modificazioni avvenute sull’edificato e la relativa vulnerabilità sismica, contribuendo ad accrescere la conoscenza della configurazione attuale della città storica. Inoltre, la verifica tramite modellazione meccanica con il software 3Muri di due parametri osservazionali e tipologici della valutazione speditiva utilizzata nell’analisi di vulnerabilità, ha permesso la validazione e la descrizione quantitativa degli apporti geometrici sugli aggregati storici.
Più generale il lavoro di ricerca mira a contribuire all’implementazione di un corpo di conoscenza relativo al comportamento del costruito in aggregato delle città storiche, che rappresenti una base scientifica su cui fondare principi e linee guida di intervento per il miglioramento delle performance del costruito esistente, ponendosi nell’ottica, di una ragionata modalità di azione sull’edificato in aggregato che non può interessarsi solo del singolo intervento edilizio prescindendo dal contesto costruito in cui si inserisce.The concept of Resilience, initially introduced in the scientific literature in the context of ecology as a way to understand the nonlinear dynamics observed in ecosystems, has evolved following independent paths in various disciplines and is today closely related to Disaster Risk Reduction (DRR).
The impact of natural and technological disasters is potentially greater in urban areas, where the high population density increases the seriousness of the socio-economic consequences due to the interruption of essential services. In the city context it is therefore necessary to strengthen the resilience characteristics, in order to increase the system capacity to absorb disturbance and change, reorganize and preserve basic structures and essential services to cope with natural disasters. The construction industry is traditionally associated with the reconstruction phase. However, today there is a growing awareness of how different professionals of the built environment play a crucial role in anticipating, evaluating and preparing response and post-disaster recovery.The built heritage holds in fact an increasingly important role in defining and increasing the urban disasters resilience. In particular, the historical Italian cities are a significant example of urban organism, able to evolve and adapt to the seismic events that have characterized the history of the country.The research work focuses on defining the role of the built heritage in the constitution of urban resilience by analyzing the correlation between masonry construction technique, morphology and seismic vulnerability of historical buildings in the urban system. The goal of the research is to provide indications and strategies to integrate the concept of urban resilience in daily logic of Land Management, which nowadays must address the issues of risk and safety as a matter of fundamental input, overcoming the limits of disciplinary specialization called in to face the damage already manifest.
In particular, the proposed approach is aimed to integrate the phase of preventive planning, demonstrating that it is possible to develop ex-ante appropriate knowledge processes and analysis on the built environment, useful to face so- called “residual risk” and to address decision-making and design choices of the professionals involved in post-disaster reconstruction.From the analysis of the reconstructions processes carried out in the last century in Italy and the reconstruction plans developed so far, it is possible to identify some key elements that constitute a shared knowledge base for preventive planning.
The settlement is vulnerable as a system, so there is need for a multi-scale approach to develop strategies and guidelines for both the “prevention” and “reconstruction” phases. From this point of view, to plan entails establishing an order of priority in which activities will take place. Through the analysis of case studies of Italian historical centers, the proposed methodology identifies preparedness strategies to the crisis by systematizing analysis on the material data of the built heritage (vulnerability analysis, character of construction and evolutionary phases of the aggregates), with urban analysis, through a matrix approach aimed at identifying priorities for action in the historic city. The chosen case studies are the historic cities of Rieti (Lazio) and San Gemini (TR – Umbria), both located in an area with upper-middle seismic hazard (zone 2) and representing a significant proportion of Italian municipalities in terms of size and population.
The research results show how the morphological features of the urban fabric and the aggregation characteristics assume significant influence on the performance of the built heritage, and how these contributions must be deepened and integrated into the current evaluation of seismic vulnerability, with a view to Land Management. The analysis on the data of the built heritage material has allowed to highlight and understand the relationship between the changes that took place on the built environment and the relative seismic vulnerability, increasing the knowledge of the current configuration of the historic city. In addition, the simulations performed with the mechanical model 3Muri, allowed the validation of two observational and typological parameters of the expeditious assessment tool used in the analysis of vulnerability. The results confirmed the relevance of geometric features of the historical aggregates on the seismic behavior.
Overall, the research work aims to contribute to the implementation of the body of knowledge on the behavior of aggregated construction of the historic cities, representing a scientific basis to support the principles and guidelines of intervention for improving the performance of existing buildings, aware that action on built heritage cannot operate only on individual buildings out of their own context.
HOW ENVIRONMENTAL CONDITIONS AND ENERGY ISSUES SHAPE THE CITIES
No full textIn a time of transformation and discussion on energy issues, the one-to-one relationship between city and energy sources of supply prompts to go over city morphology according to new renewable energy sources and technologies. The urgency of this action is motivated by the current energy-intensive condition of our settlements, accused to be the “black holes” (F. Butera, 2008) in global energy consumption accounting for more than 75% of total amount and 85% of polluting emissions. A figure doomed to grow, according to United Nation evaluations, due to the continuous process of world metropolitanization which will lead more than 80% of world population to choose urban living. Thanks to the evidences in the history of the cities, it is possible to demonstrate as urban form is tightly reliant on energy source typology and its availability on territory and, mainly, as it changes as a consequence of their development and decline. The relationships between Coketown and coke, vertical-city and electricity or horizontal-city (sprawl) and oil, give us a clear example.
The obliged transition toward new renewable sources makes us wonder on future settlement morphology, especially on possibility to use the urban design as ideal tool to reach new urban models.
More specifically, in which direction goes the historic debate on contemporary cities evolving, in this age of climate change and sustainability? What about incorporation of renewable energies and, in particular, exploitation of solar energy in urban settlements?
To date, researches mainly focus on urban density, while less attention has been paid to the form that means to the “physical qualities” of the spatial structure of the city; actually, the organization of the urban fabric in its 3 dimensions is strictly related to the potential gains of solar energy and therefore to the individual, technical and social use of the sun.
By studying an existing urban sample, this work aims at investigating the extent to which the morphological features of the fabric can affect the collection of solar radiation on the buildings envelope and public spaces, in order to define general guidelines aiding architects already in the early phases of masterplan and urban design.
In the specific study case of Eixample district by I. Cerdà in Barcelona (Spain) the attention is focused on the network orientation and on the height to width ratio, which are analysed in order to evaluate and compare the influence of obstructions and the distribution of solar flux.
This study is developed by applying a simplified comparative methodology supported by HELIODON 2, a simulation software that has not a realistic and diagnostic aim, but allows fast interaction between solar radiation and design process. Through this work, we intend to propose a more “architectural” approach as well as to provide a new methodological and operational tool for solar analysis and at urban scale
Dalla riqualificazione energetica al recupero sostenibile. Un metodo di analisi energetica dei tessuti della città compatta
No full textA dispetto della sempre maggiore “insostenibilità” della città odierna, recenti statistiche ne hanno confermato il crescente potere attrattivo; una circostanza che vede il continente europeo presentare un’assoluta prevalenza del costruito esistente sul nuovo. Per tentare di raggiungere quel complesso stato di equilibrio, che in molti fanno ricadere sotto il nome di sostenibilità, appare dunque necessario confrontarsi con il patrimonio edilizio dei tessuti storici, piuttosto che realizzarne di nuovi ad alta efficienza. Si presentano qui i risultati di uno studio comparativo condotto su diversi tessuti urbani alla ricerca di relazioni tra densità urbana e performance energetiche. Tale metodologia può rappresentare una base di conoscenza che conduca a trasformazioni consapevoli verso condizioni a maggiore efficienza
Clinical characteristics of a Dutch DFNA9 family with a novel COCH mutation, G87W.
No full textThe present study aims to report audiological and vestibular characteristics of a Dutch DFNA9 family with a novel mutation, G87W, in the LCCL domain of COCH. From the family with the novel G87W COCH mutation audiometric data were collected and analyzed longitudinally. Results were compared with those obtained in previously identified P51S COCH mutation carriers (n = 74) and with those obtained in G88E mutation carriers. Special attention was also given to a comparison of age-related features, such as progressive hearing loss and vestibular impairment. A novel mutation (G87W) in COCH is indicative of hearing impairment and vestibular dysfunction in the present family. Pure-tone thresholds, phoneme recognition scores, and vestibular responses of the G87W mutation carriers were essentially similar to those previously established in the P51S and G88E mutation carriers. Deterioration of hearing and vestibular function in the G87W mutation carriers started at the age of 43 years. Remarkably, similar to G88E mutation carriers, the proportion of patients over 40 years of age who developed complete vestibular areflexia was significantly lower for the G87W mutation carriers than for the P51S mutation carriers. In conclusion, the phenotype associated with the novel COCH (G87W) mutation is largely similar to that associated with the P51S and G88E mutation carriers. However, subtle differences in terms of onset age and rate of progression seem to exist
Reactivity of Palladium(II) Complexes Containing the Orthometalated C,C-Chelating Ligand <i>C</i><sub>6</sub>H<sub>4</sub>-2-PPh<sub>2</sub><i>C</i>(H)COCH<sub>2</sub>PPh<sub>3</sub> toward Deprotonating Reagents
No full textThe dinuclear complex [Pd(μ-Cl)(C6H4-2-PPh2C(H)COCH2PPh3)]2(ClO4)2 reacts with Hg(OOCCH3)2 (1:1 molar
ratio, CH2Cl2, room temperature) giving the trinuclear derivative [Pd2Hg(μ-Cl)2(C6H4-2-PPh2C(H)COC(H)PPh3)2](ClO4)2 (1). The X-ray structure of 1 has been determined: C78H62Cl4HgO10P4Pd2, monoclinic, I2/a, a = 20.205(3)
Å, b = 11.7529(9) Å, c = 30.905(3) Å, β = 90.333(10)°, V = 7339.0(14) Å3, Z = 4. The structure shows two
Pd atoms bridged by two Cl atoms and also shows weak Pd−Hg contacts. Both orthometalated ylide groups
[C6H4-2-PPh2C(H)COC(H)(PPh3)]- in 1 act as C,C,C-tridentate ligands, coordinated to the palladium center through
the arylic carbon atom and the ylidic carbon atom adjacent to the PPh2 group and to the mercury center through
the ylidic carbon atom adjacent to the PPh3 group. The reaction of [Pd(μ-Cl)(C6H4-2-PPh2C(H)COCH2PPh3)]2(ClO4)2 with (acac)AuPPh3 (acac = acetylacetonate; 1:2 molar ratio) affords [Pd(C6H4-2-PPh2C(H)COCH2PPh3)(acac-O,O‘)](ClO4) (2) by transmetalation of the acac group. Further treatment of 2 with (acac)AuPPh3 gives the
dinuclear derivative [Pd(C6H4-2-PPh2C(H)COCH(AuPPh3)(PPh3))(acac-O,O‘)](ClO4) (3) in which the orthometalated ylide fragment acts as a C,C,C-tridentate ligand. The reaction of [Pd(C6H4-2-PPh2C(H)COCH2PPh3)Cl(PPh3)](ClO4) with NBu4OH (1:1 molar ratio) affords [Pd(C6H4-2-PPh2C(H)COCHPPh3)Cl(PPh3)] as a mixture
of the cis and trans isomers (4a/4b), while the reaction of the same cationic precursor [Pd(C6H4-2-PPh2C(H)COCH2PPh3)Cl(PPh3)](ClO4) with (acac)AuPPh3 results in the formation of [Pd(C6H4-2-PPh2C(H)COCH(AuPPh3)(PPh3))Cl(PPh3)](ClO4) (5). The reaction of [Pd(C6H4-2-PPh2C(H)COCH2PPh3)(L−L)](ClO4)2 (L−L = dppe, phen) with
Na[N(SiMe3)2] (dppe = 1,2-bis(diphenylphosphino)ethane and phen = 1,10-phenanthroline; 1:1 molar ratio, THF,
room temperature) results in the formation of the cationic species [Pd(C6H4-2-PPh2C(H)COCHPPh3)(L−L)](ClO4) (L−L = dppe (6), phen (7)), which contain a free ylidic fragment. Complex 6 reacts with ClAu(tht) (tht
= tetrahydrothiophene; 1:1 molar ratio) giving [Pd(C6H4-2-PPh2C(H)COCH(AuCl)(PPh3))(dppe)](ClO4) (8), while
[Pd(C6H4-2-PPh2C(H)COCH2PPh3)(phen)](ClO4)2 reacts with (acac)AuPPh3 (1:1 molar ratio) affording [Pd(C6H4-2-PPh2C(H)COCH(AuPPh3)(PPh3))(phen)](ClO4)2 (9)
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