55 research outputs found
Geology and wines of Pachino - Portopalo area : preliminary outlines
This research, still in a developmental
phase, analyses geological peculiarities and the relation-
ships between them and the vineyards typical to the
Pachino-Portopalo area.
The actual knowledge does not yet allow the drawing of tourist routes from which a geo-tourist would be
able to join together Geosites and Oenosites. This will
be one of the main topics of future research, oriented
to produce substantial contributions to the sustainable
development of this area.peer-reviewe
Formulation of a Basic Constitutive Model for Fine - Grained Soils Using the Hypoplastic Framework
A hypoplastic approach to constitutive modelling was developed by Kolymbas 1996 considering a non-linear tensor function in the form of strain and stress rate. However, the implicit formulation of the hypoplastic model with indirect material parameters severely limits its applicability to real-world geotechnical problems. In many cases, the numerical analysis of geotechnical problems relies on simple elastoplastic constitutive models that cannot model a wide range of soil response aspects. One promising paradigm of constitutive modelling in geotechnics is hypoplasticity, but many of the hypoplastic models belong to advanced models. In the article, we present the simple hypoplastic model as an alternative to the widely used Mohr Coulomb elastoplastic model
The chain tower in Kyrenia’s harbour, Cyprus
[EN] In the Middle Ages a chain suspended between two towers defended the entrance of Kyrenia’s little
harbour, like the chain across the Golden Horn in Constantinople. William de Oldenburg, who visited
Cyprus in 1211 during the reign of King Hugh I, referred to Kyrenia as “a small town well-fortified,
which has a castle with walls and towers”. He perceived the chain tower as part of Kyrenia’s fortification system in that time. The Byzantines had already fortified the city, but in the thirteenth century, during the Longobard war, before the siege of the city, Frederick II’s party, under the direction of Captain
Philippo Genardo, improved the defences of the city. The chain tower is still visible today in the north
side of the old Kyrenia harbour. It consists of an 8,15 m diameter cylindrical tower and a 1,5 m diameter pillar on top of it. The tower was supporting a chain attached on the other side to another structure.
The fortifications on the north side terminated against the harbour in a square tower or bastion holding
the chain to be raised and lowered by means of a windlass. The paper includes the digital photogrammetric survey of the chain tower using a structure from motion software, the historical research and the
comparison with other coeval harbour defence constructions of the eastern Mediterranean.Camiz, A.; Griffo, M.; Baydur, S.; Valletta, E. (2020). The chain tower in Kyrenia’s harbour, Cyprus. Editorial Universitat Politècnica de València. 1085-1092. https://doi.org/10.4995/FORTMED2020.2020.11459OCS1085109
The so-called “beach-tower” of Kyrenia city walls, Cyprus
[EN] The so-called “beach-tower” is the smallest of the three remaining towers belonging to the Kyrenia’s
medieval enceinte. Semi-circular in plan, with circa 6 m of diameter, the tower is today partially obliterated by the medieval urban tissue and is visible only from one side. Built during the twelfth-thirteenth
centuries, this harbour overlooking tower is raised on a pedestal in the north-west inner corner of the
city walled enclosure. The tower shows on the outside two windows that might belong to a later phase,
being too wide as defensive openings, and includes fragments of the adjoining city walls that ran to the
east, towards the castle and to the west towards the beach city gate. Kyrenia city’s walled defensive system was dismantled by the Venetians when the use of gunpowder cannon became prevalent, however,
traces and records still remain enshrined in the medieval constructions. The paper, following the historical research, attempts to date the construction of this tower, and by examining the fortification remains
with a digital survey, applies the comparison with other coeval examples together with the comparative
analysis of the different masonry types.Camiz, A.; Griffo, M.; Valletta, E.; Khafizou, A. (2020). The so-called “beach-tower” of Kyrenia city walls, Cyprus. Editorial Universitat Politècnica de València. 1093-1100. https://doi.org/10.4995/FORTMED2020.2020.11425OCS1093110
Definition of a new multi-level early warning procedure for landslide risk management
The identification of potentially critical events involving unstable slopes is a major aspect in the field of natural hazards risk mitigation and management. In this framework, Early Warning Systems (EWS) exploiting advanced technologies represent an efficient approach to decrease the risk generated by landslide phenomena, allowing to reduce the possibility of damages and losses of human lives. EWS effectiveness has increased significantly in recent years, thanks to relevant advances in sensing technologies and data processing. In particular, the introduction of innovative monitoring instrumentation featuring automatic procedures and increased performances in terms of sampling rate and accuracy has permitted to develop EWS characterised by a near-real time approach. Among the several aspects involved in the development of a reliable Early Warning System, one of the most important is the ability to minimize the dissemination of false alarms, which should be avoided or identified in advance. The approach proposed in this study represents a new procedure aimed to assess the hazard level posed by a potentially critical event, previously identified by analysing displacement monitoring data. The process is implemented in a near-real time EWS and defines a total of five different hazard levels, on the basis of the results provided by two different models, namely an accelerating trend identification criterion and a failure forecasting model based on the Inverse Velocity Method (IVM). In particular, the forecasting analysis is performed only if the dataset elaborated by the onset-of-acceleration model highlights a potentially critical behaviour, which represents a first alert level. Following levels are determined by different conditions imposed on three parameters featured by the failure forecasting model, i.e. dataset dimension, coefficient of determination R-squared, and number of sensors displaying an accelerating trend. As these criteria get fulfilled, it is assumed that the monitored phenomenon is gradually evolving towards a more critical condition, thus reaching an increasing alert level depending on the analysis results. According to this classification, it is possible to set up for each single threshold a dedicated warning message, which could be automatically issued to authorities responsible of monitoring activities, in order to provide an adequate dissemination of information concerning the ongoing event. Moreover, the proposed procedure allows to customize the alert approach, giving the possibility to issue warning messages only if a certain Level is reached during the analysis
application of innovative monitoring tools for safety and alert procedures in road tunnels
Abstract Tunnels and underground structures are one of the most important components of road and railway networks, especially near urban areas. For this reason, it is particularly important to identify potentially hazardous conditions in order to guarantee the structure's durability and practicability. This paper presents a case study where a seismic event severely damaged a road tunnel located in Central Italy, impairing its accessibility and leading to its closure for safety reasons. Following the damage assessment, and given the importance of this specific structure, it was decided to perform a series of renovation works aimed to restore the tunnel's operability. In this context, an innovative automatic monitoring device, able to measure the structure deformation, was installed in a critical section of the road tunnel. This instrument, called Cir Array, is specifically designed for near-real time monitoring of convergence phenomena and localized deformations inside underground structures, obtaining accurate and reliable results during their operational phase. The instrumentation provided useful information about the structure's conditions, playing a major role into assessing the tunnel's accessibility and safety during the renovation works. Moreover, thanks to its automated and high frequency sampling process, it will allow the implementation of dedicated warning procedures related to the passage of the vehicles inside the tunnel
Resonant and crossover phenomena in a multiband superconductor tuning the chemical potential near a band edge
Resonances in the superconducting properties, in a regime of crossover from
BCS to mixed Bose-Fermi superconductivity, are investigated in a two-band
superconductor where the chemical potential is tuned near the band edge of the
second mini-band generated by quantum confinement effects. The shape resonances
at T=0 in the superconducting gaps (belonging to the class of Feshbach-like
resonances) is manifested by interference effects in the superconducting gap at
the first large Fermi surface when the chemical potential is in the proximity
of the band edge of the second mini-band. The case of a superlattice of quantum
wells is considered and the amplification of the superperconducting gaps at the
3D-2D Fermi surface topological transition is clearly shown. The results are
found to be in good agreement with available experimental data on a
superlattice of honeycomb boron layers intercalated by Al and Mg spacer layers.Comment: 13 pages, 9 image
Thymol-functionalized hyaluronic acid as promising preservative biomaterial for the Inhibition of Candida albicans biofilm formation
Hyaluronic acid (HA) is a naturally occurring biopolymer that has been employed for a plethora of medicinal applications. Nevertheless, as HA is a natural polysaccharide, it can be a substrate able to promote microbial growth and proliferation. Biopolymer–drug conjugates have gained attention over the years to overcome drawbacks of each single component. Within this context, thymol (Thy), a phenolic compound occurring in essential oils (EOs) extracted from Thymus and Origanum, has been largely studied for its antimycotic applications. However, it is characterized by a low water solubility and moderate cytotoxicity. Herein, we report an innovative HA–thymol conjugate (HA-Thy) biomaterial to circumvent the drawbacks of free thymol use by providing the polymer conjugate with the beneficial properties of both components. Preliminary biological tests evidenced the decrease of thymol cytotoxicity for the HA-Thy conjugate, paired with a promising antibiofilm formation activity against Candida albicans, similar to pure thymol, highlighting its potential application as a preservative biomaterial in formulations
Infective Endocarditis: A Focus on Oral Microbiota
Infective endocarditis (IE) is an inflammatory disease usually caused by bacteria entering the bloodstream and settling in the heart lining valves or blood vessels. Despite modern antimicrobial and surgical treatments, IE continues to cause substantial morbidity and mortality. Thus, primary prevention and enhanced diagnosis remain the most important strategies to fight this disease. In this regard, it is worth noting that for over 50 years, oral microbiota has been considered one of the significant risk factors for IE. Indeed, among the disparate recommendations from the American heart association and the European Society of Cardiology, there are good oral hygiene and prophylaxis for high-risk patients undergoing dental procedures. Thus, significant interest has grown in the role of oral microbiota and it continues to be a subject of research interest, especially if we consider that antimicrobial treatments can generate drug-resistant mutant bacteria, becoming a severe social problem. This review will describe the current knowledge about the relationship between oral microbiota, dental procedures, and IE. Further, it will discuss current methods used to prevent IE cases that originate from oral pathogens and how these should be focused on improving oral hygiene, which remains the significant persuasible way to prevent bacteremia and systemic disorders
GROUND TEMPERATURE MONITORING FOR A COAXIAL GEOTHERMAL HEAT EXCHANGERS FIELD: PRACTICAL ASPECTS AND MAIN ISSUES FROM THE FIRST YEAR OF MEASUREMENTS
Plitka, potpovršinska, temperatura (na dubinama plićim od 50 m) nije konstantna, niti u prostoru, niti vremenu. Takve promjene posljedica su utjecaja toplinskih „pulseva” različitoga podrijetla poput Sunčeva, geotermalnoga ili ljudskoga. Točna procjena temperature ključni je čimbenik kod planiranja energetskih sustava temeljenih na plitkoj geotermalnoj energiji. U takvim projektima, temeljenim na izmjenjivačima topline u plitkim bušotinama, potpovršinska je temperatura promjenjivija, što utječe na iznos pridobivanja topline, tj. utiskivanja fluida. Praćenje takvih promjena važno je stoga kod svih projekata toplinskih izmjenjivača vezanih uz plitka geotermalna ležišta. U radu je prikazan praktičan oblik toga, ali i glavni problemi koje je moguće susresti tijekom instaliranja, testiranja ili uporabe potrebne geotermalne opreme. Dan je primjer polja u kojemu je smješteno osam koaksijalnih izmjenjivača topline, 30 metara dugačkih te povezanih s prototipom uređaja dvostruke toplinske crpke (zračne i dubinske).Ground temperature at shallow depth (< 50 m) is not stable, nor in space, neither in time, and its behaviour is the result of superimposition of effects of heat pulses of different origin: solar, geothermal and anthropic. The correct assessment of ground temperature is a crucial point when designing a shallow geothermal energy system. In geothermal closed loop projects, more the borehole heat exchangers are short, more the contribution of the ground temperature variability on the heat exchange is prominent. Monitoring ground temperature can be very useful to correctly understand the behaviour of a shallow geothermal reservoir subjected to heat extraction and/or injection by a ground source heat pump system. The present work illustrates the practical aspects and main issues occurred in the installation, testing and working phases of a monitoring system realised to record ground temperature in a geothermal application. The case study is a field of eight coaxial borehole heat exchangers, 30 m long, connected to a novel prototype of dual source (air and ground) heat pump
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