Acquisition, classification, and analysis of seismic data are crucial tasks in volcano monitoring. The large number of seismic signals that are continuously acquired during the first monitoring stage ...poses a huge challenge for the human experts that must classify and analyze them. Several automatic classification systems have been proposed in the literature to alleviate such an overwhelming workload, each one characterized by different levels of accuracy, computational complexity, and interpretability. Considering this last perspective, which represents one of the recent key issues in geoscience, it is possible to find many accurate methods (in terms of classification accuracy) which however represent black boxes, not permitting a clear interpretation. On the other hand, there are other approaches, such as those based on support vector machines (SVM), random forests (RF), and K-nearest neighbor (KNN), which permit the interpretation of results, rules, and models at different levels. Among these last techniques, KNN approaches for volcanic signal classification typically do not achieve the satisfactory classification results obtained with RF and SVM. One possible reason is that in this context, the KNN rule has usually been applied in its basic version, not exploiting the different advanced KNN variants that have been introduced in recent years. This paper takes one step along this direction, investigating the suitability of a number of advanced versions of the KNN rule for the problem of classifying seismic-volcanic signals. The usefulness of these rules, in comparison with the original KNN rule as well as other interpretable classifiers, is evaluated within a real-world scenario involving a five-class dataset of seismic signals acquired at the Nevado del Ruiz volcano, Colombia. The results show that the classification accuracy of basic KNN is largely improved by these advanced variants, even surpassing that obtained with other classifiers like RF and SVM.
Odontogenic orbital abscess is a rare but well-documented complication of sinusitis and infections spreading from dental apical lesion. We report a case of orbital abscess with periorbital ...cellulitis, in a 35-year-old man with positive recent dental history of a periapical dental infection arising from the second upper left premolar spread into maxillary sinus. The patient has shown facial edema, ocular pain, ophthalmoplegia, proptosis, and initial visual symptoms. A surgical intervention to drain the abscess and a revision of the dental lesion and maxillary sinus were required. A review of literature is also reported focusing on etiology and treatment options dealing with odontogenic orbital abscess and cellulitis.
Antenatal stress is linked to fetal risks that increase the chances of neonatal complications and reduction of child cognitive ability. Therefore, we aimed to evaluate if maternal stress affects ...fetal, neonatal or child development. The following databases were searched: MEDLINE (1966 to May 2016), Embase (1980 to May 2016), LILACS (1982 to May 2016) and CENTRAL (1972 to May 2016). Observational studies published in English and Portuguese were included whether there was any relationship between fetal and neonatal outcome, such as birth weight, preterm labor, child development with pregnant women that were subjected to any stress type during at least one month of follow-up. Two independent reviewers screened eligible articles, extracted data and assessed the risk of bias. Thus, 8 cohort studies with about 8,271 pregnant women and 1,081,151 children proved eligible. Results suggested a significant association between antenatal stress exposure and increasing rates of low birth weight (Odds ratio (OR) 1.68 95% Confidential Interval (CI) 1.19, 2.38). However, there was no statistically significance difference between non-exposed and exposed groups related to preterm labor (OR 1.98 95% CI 0.91 to 4.31; I2 = 68%, p = 0.04). Although, results were inconsistent with primary analysis suggesting a significant association between antenatal stress exposure and the occurrence of higher rates of preterm birth (OR 1.42 95% CI 1.05 to 1.91; I2 = 68%, p = 0.04) in the sensitivity analysis. Furthermore, the current review has suggested that stress perceived during antenatal negatively influences fetal life and child development. Yet, further studies are necessary with adequate sample size and longer follow-up time to confirm our findings.
Engaging with a scene of the iconic movie Smoke (by Wayne Wang, 1995) in which a rephotographic project is sensitively elicited, this paper addresses the technique of repeat photography to contribute ...to methodological debates that have arisen within the nascent 'Mobility and Humanities' subfield. Through a humanistic perspective, the paper reviews and expands the nexus between mobility, photography and the urban by comparing the technique with three methodological issues: the blurring of supposed binaries, such as traditional/innovative, static/moving and fast/slow; the possibility of grasping the mobilities of the world in a post-human vein; and the opportunity to also consider techniques as sites for reflection. To address these issues, the paper draws from philosophies of movement, post-phenomenological and object-oriented stances and visual and urban cultural geographies. With reference to the urban realm, this paper proposes three perspectives on rephotography, namely (1) rephotography as a practice of slow and rhythmic attunement with circumstantial spacetimes moving backwards and forwards; (2) rephotography as a visual ontography that displaces the human and opens up space for the apprehension of the agency and mobility of things; and (3) rephotography as a continual process of activation of moving gazes on cities and their imaginaries.
•Condensation heat transfer is studied inside a mini microfin tube.•Heat transfer coefficients and frictional pressure drops are obtained from the experimental measurements.•Experimental heat ...transfer coefficients and frictional pressure drops are compared against values predicted by empirical correlations.
This paper shows experimental results about R1234yf condensation inside a microfin tube with an inner diameter at the fin tip of 3.4 mm. R1234yf is a new environmentally friendly refrigerant, with a Global Warming Potential lower than 1, therefore it matches the new environmental laws. Experimental tests are carried out for mass velocities from 100 to 1000 kg m−2 s−1, vapor qualities from 0.95 to 0.2, at saturation temperature of 30 °C and 40 °C. The experimental results show that heat transfer coefficient increases when both mass velocity and vapor quality increase. Frictional pressure gradient increases with mass velocity at constant vapor quality, whereas at constant mass velocity it increases with vapor quality up to a maximum, after which it slightly decreases. The experimental heat transfer coefficient and pressure drop are also compared against the values predicted by empirical correlations available in the open literature.
To assess agreement among ophthalmology residents and a glaucoma expert in the evaluation of cross-sectional glaucomatous optic nerve head characteristics using stereoscopic photographs.
Twenty ...stereo photographs were analyzed by ophthalmology residents just after completion of their first (First-Year Group) or third (Third-Year Group) year of residency and by a glaucoma expert. The agreement was assessed using the kappa statistic (κ) and limits of agreement.
Agreement among resident groups and the expert ranged from poor to moderate. Agreement between Third Years and the expert seems to be better than that between First Years and the expert, especially in the evaluation of "nasal cupping", "barring circumlinear vessel," "notching", and "retinal nerve fiber layer defect" criteria. However, no improvement was seen in the agreement with the expert regarding glaucomatous optic neuropathy, which was 64% (κ=0.19) for First Years and 63% (κ=0.20) for Third Years.
Agreement between residents and the expert was poor to moderate and similar when comparing both groups. This may suggest that the residents learn how to identify glaucoma signals during the first year of training, and the results of this study may facilitate the creation of targeted teaching tools in residency training.
•Condensation heat transfer is studied inside a 2.4 mm ID mini microfin tube.•Heat transfer coefficients and frictional pressure drops are obtained from the experimental measurements.•Experimental ...heat transfer coefficients and frictional pressure drops are compared against values predicted by empirical correlations.
This paper explores the possible use of R1234yf and R1234ze(E) during condensation inside a microfin tube with an inner diameter at the fin tip of 2.4 mm as replacement of R134a. Having thermodynamic properties close to those of R134a, R1234yf and R1234ze(E) are some of its possible replacements for air conditioning and refrigeration systems. Experimental tests were carried out for mass velocities from 300 to 1000 kg m−2 s−1, vapor qualities from 0.95 to 0.2, at saturation temperatures of 30 °C and 40 °C. From the experimental measurements, it has been possible to calculate the heat transfer coefficient and to measure the frictional pressure drop. Globally speaking, R1234ze(E) shows heat transfer coefficients similar to those of R134a, whereas R1234yf shows slightly lower values. R1234ze(E) frictional pressure drops are some 30% higher than those of R134a, whereas R1234yf shows values similar to R134a. The experimental results of heat transfer coefficient and frictional pressure drop were also compared against values predicted by empirical correlations.
This paper investigates the heat transfer performance of two 20 PPI (pores per linear inch) aluminum foams with constant porosity (around 0.93) and different foam core height (20 mm and 40 mm). The ...aluminum foams are cellular structure materials that present a stochastic interconnected pores distribution mostly uniform in size and shape. Most commercially available metal foams are based on aluminum, copper, nickel and metal alloys. Metal foams have considerable applications in multifunctional heat exchangers, cryogenics, combustion chambers, cladding on buildings, strain isolation, petroleum reservoirs, compact heat exchangers for airborne equipment, air cooled condensers and compact heat sinks for power electronics. The experimental measurements of the heat transfer coefficient and pressure drop have been carried out in a test apparatus built at Dipartimento di Fisica Tecnica of the Università di Padova. The foam core height effects on the heat transfer performance have been studied imposing three constant specific heat fluxes at the bottom of the samples: 25.0, 32.5 and 40.0 kW m−2 and varying the frontal air velocity between 2.0 and 5.0 m s−1. The experimental heat transfer coefficients and pressure gradients have been compared against the predictions obtained from two models recently suggested by present authors.
► Foam height effects on the heat transfer performance of 20 PPI foams are investigated. ► Heat transfer coefficients and pressure drops during air flow are presented. ► Two models suggested by the authors are compared with present experimental data.
IntroductionThe epidemiological surveillance of mesothelioma incidence is a crucial key for investigating the occupational and environmental sources of asbestos exposure. The median age at diagnosis ...is generally high, according to the long latency of the disease. The purposes of this study are to analyse the incidence of mesothelioma in young people and to evaluate the modalities of asbestos exposure.MethodsIncident malignant mesothelioma (MM) cases in the period 1993–2018 were retrieved from Italian national mesothelioma registry and analysed for gender, incidence period, morphology and exposure. Age-standardised rates have been calculated and the multiple correspondence analysis has been performed. The association between age and asbestos exposure has been tested by χ2 test.ResultsFrom 1993 to 2018, 30 828 incident MM cases have been collected and 1278 (4.1%) presented diagnosis at early age (≤50 years). There is a substantial association between age at diagnosis and the type of asbestos exposure and a significantly lower frequency of cases with occupational exposure to asbestos (497 cases vs 701 expected) in young people has been documented. Paraoccupational and environmental exposure to asbestos have been found more frequent in young MM cases (85 and 93 observed cases vs 52 and 44 expected cases, respectively).ConclusionsMesothelioma incidence surveillance at population level and the anamnestic individual research of asbestos exposure is a fundamental tool for monitoring asbestos exposure health effects, supporting the exposure risks prevention policies. Clusters of mesothelioma incident cases in young people are a significant signal of a potential non-occupational exposure to asbestos.
Pressure drop during air flow in aluminum foams Mancin, Simone; Zilio, Claudio; Cavallini, Alberto ...
International journal of heat and mass transfer,
07/2010, Volume:
53, Issue:
15
Journal Article
Peer reviewed
This paper aims at investigating experimentally the pressure drop during air flow in six different aluminum open-cell foam samples with different number of pores per inch (PPI) and different porosity ...under a wide range of air mass flow rate. Three imposed heat fluxes are considered for each foam sample. The collected pressure drop data are analysed with reference to models available in the literature. A new simple pressure drop model, based on present data, has then been developed. The consistency of the proposed model is finally checked by comparison to data available in the literature from different laboratories.
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