260 research outputs found
nZVI mobility and transport: laboratory test and numerical model
Zerovalent iron nanoparticles (nZVI) are becoming one of the most widely recommended nanomaterials for soil and groundwater remediation. However, when nZVI are injected in the groundwater flow, the behavior (mobility, dispersion, distribution) is practically unknown. This fact generally results in the use of enormous quantities of them at the field scale. The uncertainties are on the effective volumes reached from the plume of nZVI because their tendency to aggregate and their weight can cause their settling and deposition. So, the mobility of nanoparticles is a real issue, which can often lead to inefficient or expensive soil remediation. Furthermore, there is another aspect that must be considered: the fate of these nZVI in the groundwater and their possible impact on the subsoil environment. All these considerations have led us to propose an application of nZVI simulating the permeation technique through a laboratory experience, finalized to have a better, or even simpler description of their real behavior when injected in a flow in the subsoil. A two-dimensional laboratory-scale tank was used to study the dispersion and transport of nZVI. A nZVI solution, with a concentration equal to 4.54 g/L, was injected into glass beads, utilized as porous medium. The laboratory experiment included a digital camera to acquire the images. The images were then used for calibrating a numerical model. The results of the mass balance confirm the validity of the proposed numerical model, obtaining values of velocity (5.41 x 10(-3) m/s) and mass (1.9 g) of the nZVI of the same order of those from the experimental tests. Several information were inferred from both experimental and numerical tests. Both demonstrate that nZVI plume does not behave as a solute dissolved in water, but as a mass showing its own mobility ruled mainly from the buoyancy force. A simple simulation of a tracer input and a nZVI plume are compared to evidence the large differences between their evolution in time and space. This means that commercial numerical models, if not corrected, cannot furnish a real forecast of the volume of influence of the injected nZVI. Further deductions can be found from the images and confirmed by means the numerical model where the detachment effect is much smaller than the attachment one (ratio k(d)/k(a) = 0.001). From what is reported, it is worthwhile to pay attention on the localization of the contaminants source/plume to reach an effective treatment and it is important to go further in the improvement of solution for the limiting the nanoparticles aggregation phenomenon
Augmented-reality within computer assisted orthopaedic surgery workflows: a proof of concept study
The integration of augmented-reality (AR) in medical robotics has been shown to reduce cognitive burden and improve information management in the typically cluttered environment of computer-assisted surgery. A key benefit of such systems is the ability to generate a composite view of medical-informatics and the real environment, streamlining the pathway for delivering patient-specific data. Consequently, AR was integrated within an orthopaedic setting by designing a system that captured and replicated the user- interface of a commercially available surgical robot onto a commercial head mounted see through display. Thus, a clinician could simultaneously view the operating-site and real- time informatics when carrying out an assisted patellofemoral-arthroplasty (PFA). The system was tested with 10 surgeons to examine its usability and impact on procedure- completion times when conducting simulated PFA on sawbone models. A statistically insignificant mean increase in procedure completion-time (+23.7s, p=0.240) was found, and the results of a post-operative qualitative-evaluation indicated a strongly positive consensus on the system, with a large majority of subjects agreeing the system provided value to the procedure without incurring noticeable physical discomfort. Overall, this study provides an encouraging insight into the high levels of engagement AR has with a clinical audience as well as its ability to enhance future generations of medical robotics
Surface doping in T6/ PDI-8CN2 Heterostructures investigated by transport and photoemission measurements
In this paper, we discuss the surface doping in sexithiophene (T6) organic
field-effect transistors by PDI-8CN2. We show that an accumulation
heterojunction is formed at the interface between the organic semiconductors
and that the consequent band bending in T6 caused by PDI-8CN2 deposition can be
addressed as the cause of the surface doping in T6 transistors. Several
evidences of this phenomenon have been furnished both by electrical transport
and photoemission measurements, namely the increase in the conductivity, the
shift of the threshold voltage and the shift of the T6 HOMO peak towards higher
binding energies.Comment: 5 pages, 5 figure
The Emerging Trends of Renewable Energy Communities’ Development in Italy
Increasing concerns over climate change and energy poverty have triggered the transition toward a decentralized energy system through the widespread adoption of renewable energy technologies. Although this transition was led, over past decades, mainly by major investors and large industrial players, citizens and local authorities are increasingly playing an active role in delivering clean energy investments. In particular, the current European Renewable Energy Directive introduced Renewable Energy Communities (RECs), which allow citizens to collectively organize their participation in the energy market, leading to a more distributed renewable energy system and new forms of sustainable, collaborative, and democratic economies. RECs currently under implementation show differences among European countries due to the different national contexts. A literature review exploring the peculiar Italian regulatory framework on RECs and its recent evolution has been carried out to identify available national and regional financial support mechanisms, barriers, and emerging trends in the diffusion of RECs across the country. The paper reviews and describes three main approaches that emerged in the development of RECs in Italy, discussing their strengths,
and limitations. In addition, it provides a brief comparison of the regulatory framework in different European countries, highlighting the distinctive features of the Italian experience. Although the development of RECs in Italy involved a combination of both public and private initiatives, the leading role of local authorities as promoters and aggregators of RECs is evident. This role helps preserve the social impact of RECs but might slow down their implementation due to bureaucratic issues often linked to public procedures and procurement processes, as well as the lack of sufficient
expertise within local authorities
Surgical management of gynecomastia: Experience of a general surgery center
Aim. Gynecomastia is a common finding in male population of all ages. The aim of our study was to present our experience and goals in surgical treatment of gynecomastia. Patients and Methods. Clinical records of patients affected by gynecomastia referred to our Department of Surgery between September 2008 and January 2015 were analyzed. 50 patients were included in this study. Results. Gynecomastia was monolateral in 12 patients (24%) and bilateral in 38 (76%); idiopathic in 41 patients (82%) and secondary in 9 (18%). 39 patients (78%) underwent surgical operation under general anaesthesia, 11 (22%) under local anaesthesia. 3 patients (6%) presented recurrent disease. Webster technique was performed in 28 patients (56%), Davidson technique in 16 patients (32%); in 2 patients (4%) Pitanguy technique was performed and in 4 patients (8%) a mixed surgical technique was performed. Mean surgical time was 80.72±35.14 minutes, median postoperative stay was 1.46±0.88 days. 2 patients (4%) operated using Davidson technique developed a hematoma, 1 patient (2%) operated with the same technique developed hypertrophic scar. Conclusions. Several surgical techniques are described for surgical correction of gynecomastia. If performed by skilled general surgeons surgical treatment of gynecomastia is safe and permits to reach satisfactory aesthetic results
UBEM's archetypes improvement via data-driven occupant-related schedules randomly distributed and their impact assessment
In Urban Building Energy Models (UBEMs), buildings are usually modelled via archetypes describing occupants’
behaviour via fixed schedules. This research (i) creates data-driven schedules for electric use and occupancy from
smart meter readings randomly distributed in the model to improve residential archetypes, (ii) assesses the
impact of these schedules on UBEMs’ energy results at different temporal resolutions and spatial scales. The
novel assessment procedure exploits integrated heat maps based on coefficients of variation of the root means
square error (CVRMSE). The outcomes show that differences in energy needs, with randomized schedules, range
based on temporal and spatial aggregation. Yearly, for the entire neighbourhood, heating and cooling energy
needs, and electric uses are estimated -2%, +1%, and +18% compared to the base case. The outputs show that,
when simulations are focused on the entire district, fixed schedules can be enough to describe energy patterns.
However, if the simulation is focused on small groups of buildings (e.g., 5 or fewer), randomising the schedules
can create variability in the model in terms of electric use and occupancy among buildings characterized by the
same archetype. The followed methodology can be exploited also with larger databases and eventually verified
with also other types of data
Doubling the Mechanical Properties of Spider Silk by C60 Supersonic Molecular Beam Epitaxy
Spider silk is one of the most fascinating natural materials, owing to its outstanding mechanical properties. In fact, it is able to combine usually self-excluding properties, like strength and toughness that synthetic fibers fail to replicate. Here, we report a method to further enhance the already excellent mechanical properties of spider's silk, producing nanocomposite fibers where the matrix of spider silk is reinforced with C60 molecules. These are deposited by Supersonic Molecular Beam Epitaxy (SuMBE) and are able to efficiently interact with silk, as evidenced by XPS analysis. As a consequence, upon proper adjustment of the fullerene kinetic energy, the treated fibers show improved strength, Young's modulus and toughness
Manipulation of inverted and direct opals by a focused ion beam scanning electron microscope (FIB SEM)
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Is Eriophyes mali Nalepa present in Italy?
In the last few years, blistering symptoms were observed on apple plants in commercial orchards. Blisters are commonly found on apple leaves as well as on small fruits. This symptom is compatible with that described for apple blister mites belonging to the genus Eriophyes (Eriophyidae). To assess the identity of the etiological agent, leaf blisters and buds of symptomatic apple and, as a control, pear plants were examined under the dissection microscope and eriophyoid mites were collected. Specimens were examined using both molecular and morphological approaches. The analysis of sequences confirmed that eriophyoid mites collected from symptomatic apple and pear plants are genetically different. Our analyses highlight a complex scenario inside the genus Eriophyes that is worth to be studied in more detai
Genome-scaled phylogeny of Saccharomyces cerevisiae from spontaneous must fermentations
Modern winemakers commonly inoculate selected S. cerevisiae strains in must to obtain controlled fermentations and reproducible products. However, wine has been produced for thousands of years using spontaneous fermentations from wild strains, a practice that is experiencing a revival among small wine producers. Despite the widespread usage of such strains in the past, there is much to know about their ecology, evolution and functional potential. For example, the reciprocal affinities of these strains within the S. cerevisiae phylogeny have yet to be discovered, as well as the degree of their biodiversity and their impact on wine terroir. To fill this knowledge gap, we aim at characterising at strain level the S. cerevisiae present in spontaneously fermented musts sampled across Italy. We set up a protocol based on polyphenols-removing prewashes, followed by whole-genome shotgun sequencing at a depth of 5Gb of DNA per sample. We performed both an assembly-free analysis to reconstruct the strain-level phylogeny of S. cerevisiae strains using the species-specific-marker based StrainPhlAn, and the reconstruction of Metagenome-Assembled Genomes of these strains for downstream functional analyses. To plan conservation acts in a scenario of continuous climate change, we aim at isolating and maintaining strains of interest. We will present preliminary results from the analysis of spontaneous musts sampled at different fermenting stages
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