541 research outputs found
From Computational Fluid Dynamics to Structure Interpretation via Neural Networks: An Application to Flow and Transport in Porous Media
The modeling of flow and transport in porous media is of the utmost importance in many chemical engineering applications, including catalytic reactors, batteries, and CO2 storage. The aim of this study is to test the use of fully connected (FCNN) and convolutional neural networks (CNN) for the prediction of crucial properties in porous media systems: The permeability and the filtration rate. The data-driven models are trained on a dataset of computational fluid dynamics (CFD) simulations. To this end, the porous media geometries are created in silico by a discrete element method, and a rigorous setup of the CFD simulations is presented. The models trained have as input both geometrical and operating conditions features so that they could find application in multiscale modeling, optimization problems, and in-line control. The average error on the prediction of the permeability is lower than 2.5%, and that on the prediction of the filtration rate is lower than 5% in all the neural networks models. These results are achieved with at least a dataset of ~ 100 CFD simulations
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An analysis of commercial real estate returns: an anatomy of smoothing in asset and index returns
In this article, we investigate the commonly used autoregressive filter method of adjusting appraisal-based real estate returns to correct for the perceived biases induced in the appraisal process. Many articles have been written on appraisal smoothing but remarkably few have considered the relationship between smoothing at the individual property level and the amount of persistence in the aggregate appraisal-based index. To investigate this issue we analyze a large sample of appraisal data at the individual property level from the Investment Property Databank. We find that commonly used unsmoothing estimates at the index level overstate the extent of smoothing that takes place at the individual property level. There is also strong support for an ARFIMA representation of appraisal returns at the index level and an ARMA model at the individual property level
Validation of landslide hazard assessment by means of GPS monitoring technique ? a case study in the Dolomites (Eastern Alps, Italy)
International audienceIn the last years a research project aimed at the assessment of the landslide hazard and susceptibility in the high Cordevole river basin (Eastern Dolomites, Italy) have been carried out. The hazard map was made adopting the Swiss Confederation semi-deterministic approach that takes into account parameters such as velocity, geometry and frequency of landslides. Usually these parameters are collected by means of geological and morphological surveys, historical archive researches, aerophotogrammetric analysis etc. In this framework however the dynamics of an instable slope can be difficult to determine. This work aims at illustrating some progress in landslide hazard assessment using a modified version of the Swiss Confederation semi-deterministic approach in which the values of some parameters have been refined in order to accomplish more reliable results in hazard assessment. A validation of the accuracy of these new values, using GPS and inclinometric measurements, has been carried out on a test site located inside the high Cordevole river basin
Unimpaired Neuropsychological Performance and Enhanced Memory Recall in Patients with Sbma: A Large Sample Comparative Study.
Peculiar cognitive profile of patients with SBMA has been described by fragmented literature. Our retrospective study reports the neuropsychological evaluations of a large cohort of patients in order to contribute towards the understanding of this field. We consider 64 neuropsychological evaluations assessing mnesic, linguistic and executive functions collected from 2013 to 2015 in patients attending at Motor Neuron Disease Centre of University of Padova. The battery consisted in: Digit Span forwards and backwards, Prose Memory test, Phonemic Verbal fluency and Trail making tests. ANCOVA statistics were employed to compare tests scores results with those obtained from a sample of healthy control subjects. Multiple linear regressions were used to study the effect on cognitive performance of CAG-repeat expansion, the degree of androgen insensitivity and their interaction to cognitive performance. Statistical analyses did not reveal altered scores in any neuropsychological tests among those adopted. Interestingly, patients performed significantly better in the Prose Memory test's score. No relevant associations were found with genetic, hormonal or clinical patients' profile. Results inconsistent with previous studies have been interpreted according to the phenomenon of somatic mosaicism. We suggest a testosterone-related and the mood state-dependant perspectives as two possible interpretations of the enhanced performances in the Prose Memory test. Further studies employing more datailed tests batteries are encouraged
Fiber opticsensors for precursory acoustic signals detection in rockfall events
Two fiber optic sensors (FOSs) for detection of precursory acoustic emissions in rockfall events are addressed and experimentally characterized. Both sensors are based on interferometric schemes, with the first one consisting of a fiber coil used as sensing element and the second one exploiting a micro-machined cantilever carved on the top of a ferrule. Preliminary comparisons with standard piezo-electric transducers shows the viability of such FOSs for acoustic emission monitoring in rock masses
Site investigation and modelling at "La Maina" landslide (Carnian Alps, Italy)
International audienceThe Sauris reservoir is a hydroelectric basin closed downstream by a 136 m high, double arc concrete dam. The dam is firmly anchored to a consistent rock (Dolomia dello Schlern), but the Lower Triassic clayey formations, cropping out especially in the lower part of the slopes, have made the whole catchment basin increasingly prone to landslides. In recent years, the "La Maina landslide" has opened up several joints over a surface of about 100 000 m2, displacing about 1 500 000 m3 of material. Particular attention is now being given to the evolution of the instability area, as the reservoir is located at the foot of the landslide. Under the commission of the Regional Authority for Civil Protection a numerical modelling simulation in a pseudo-time condition of the slope was developed, in order to understand the risk for transport infrastructures, for some houses and for the reservoir and to take urgent mesaures to stabilize the slope. A monitoring system consisting of four inclinometers, three wire extensometers and ten GPS bench-mark pillars was immediately set up to check on surface and deep displacements. The data collected and the geological and geomorphological evidences was used to carry out a numerical simulation. The reliability of the results was checked by comparing the model with the morphological evidence of the movement. The mitigation measures were designed and realised following the indications provided by the model
Conservative treatment for hypervascularised placental polyp with secondary haemoperitoneum: A case report
Objective: We describe the first case to our knowledge of hypervascularised placental polyp (HPP) presenting with acute pelvic pain and hemoperitoneum. Case Report: A 33 years-old woman with a history of medical abortion three months earlier came to our attention complaining acute pelvic pain and vaginal bleeding. Transvaginal (TV) and transabdominal (TA) ultrasound (US) demonstrated a highly vascular intrauterine lesion and intra-abdominal free fluid consistent with a diagnosis of haemoperitoneum. Emergency laparoscopy yielded no intra-abdominal bleeding and was followed by bilateral selective embolization of the uterine arteries due to persistent vaginal bleeding. Hysteroscopy and pathology findings were consistent with a final diagnosis of HPP. Conclusion: HPP may occur months or years after pregnancy or abortion and the clinical picture of abnormal vaginal bleeding associated with acute abdominal pain and haemoperitoneum should warrant to consider HPP among the differential diagnosis. Clinical and imaging findings need to be considered when planning the conservative management of HPP. Our experience suggests that uterine artery embolization is a safe and effective for the conservative treatment of highly vascularized HPP. (www. actabiomedica.it)
Landslide hazard evaluation by means of several monitoring techniques, including an acoustic emission sensor
At Passo della Morte in the Italian Eastern Alps a geomorphological survey has identified potential instability of the valley side slope that could result in a debris/rock avalanche, which would threaten the Tagliamento River. A nationally important road passes through a tunnel 130 m long behind the potentially unstable slope. The stratum comprises a sequence of Limestone layers, dipping in the slope direction towards the river. Although currently there is no clear evidence of movement, the geological setting indicates a predisposition to instability that could involve a large landslide and extremely fast deformations can be foreseen. To appraise the physical characteristics of the rock mass and to provide an early warning of instability, monitoring instrumentation has been installed and monitored since late 2010. Extensometers, MEMS, TDR cables, a ver-tical inclinometer, a seismic station to monitor Limestone rock mass deformation generated micro-tremors and an acoustic emission (AE) monitoring system have been installed. The instruments are connected to real-time recording and transmitting units. The paper describes the geological setting and associated potential modes of instability. It details the design of the instrument installations and presents results obtained to date. In particular, the novel acoustic emission monitoring approach is described including sensor design, method of operation and comparison of the measured AE response with the deformation measurements and detected micro-tremor trends. Initial results indicate a strong response of the acoustic sensors to rainfall events. No sig-nificant rock mass deformations have been detected at depth within the slope to date, although a surface ex-tensometer has shown widening of a bedding tension crack. Upgrading of the instrumentation system is ongo-ing and it is planned to continue monitoring for the foreseeable future
In Vivo Evaluation Of Complex Biogenic Silver Nanoparticle And Enoxaparin In Wound Healing
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The burns treatment is difficult, uncomfortable for the patient, and expensive for health system. Due to antimicrobial properties of silver nanoparticles (AgNP), these particles can avoid bacterial infection in wound and accelerate the wound healing. Furthermore, the complexation of AgNP with enoxaparin (low molecular weight heparin) may improve the healing process of lesions due to anti-inflammatory and angiogenic activity of enoxaparin (Enox). The aim of this study was evaluated the activity and toxicity of biogenic AgNP and AgNP complexed with Enox in in vivo burn wound model. AgNP was produced by biosynthesis method using Fusarium oxysporum. AgNP (20-40 nm) exhibited high stability due to protein capping around the particles that was confirmed by TEM, fluorescence spectroscopy, and FTIR. The wound contraction in in vivo model, after 28 days of treatment, was 55, 89, 91, and 95% for control, Enox, AgNP, and AgNP-Enox groups, respectively. No clear toxic effects in the biochemistry and hematological parameters were verified in all treated groups. However, in the AgNP-Enox group, a statistically significant increase in the urea levels was observed indicating increased proteolysis due to inflammation process. The results demonstrated that the complex AgNP-Enox is interesting for wound healing decreasing the time of lesions healing.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
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