Fluid statics of a self-gravitating perfect-gas isothermal sphere

We open the paper with introductory considerations describing the motivations of our long-term research plan targeting gravitomagnetism, illustrating the fluid-dynamics numerical test case selected for that purpose, that is, a perfect-gas sphere contained in a solid shell located in empty space sufficiently away from other masses, and defining the main objective of this study: the determination of the gravitofluid-static field required as initial field ($t=0$) in forthcoming fluid-dynamics calculations. The determination of the gravitofluid-static field requires the solution of the isothermal-sphere Lane-Emden equation. We do not follow the habitual approach of the literature based on the prescription of the central density as boundary condition; we impose the gravitational field at the solid-shell internal wall. As the discourse develops, we point out differences and similarities between the literature's and our approach. We show that the nondimensional formulation of the problem hinges on a unique physical characteristic number that we call gravitational number because it gauges the self-gravity effects on the gas' fluid statics. We illustrate and discuss numerical results; some peculiarities, such as gravitational-number upper bound and multiple solutions, lead us to investigate the thermodynamics of the physical system, particularly entropy and energy, and preliminarily explore whether or not thermodynamic-stability reasons could provide justification for either selection or exclusion of multiple solutions. We close the paper with a summary of the present study in which we draw conclusions and describe future work.Comment: 32 pages, 26 figure

Human and social capital in rural areas

This thematic issue of Studies in Agricultural Economics is composed of papers that examine human and social capital in rural development. The idea behind this choice of topic is to get a picture of the kind of research currently being undertaken in this field, how this research covers the important issue of rural development, in a world where there is “a shift toward a service orientated and knowledge-based economy based on individuals creativity in using accessible information to benefit and create values for themselves and others” (Salenbacher, 2015, p46), where there are “changes brought by technology, connectivity” (ibid. p.44), and an added challenge: climate change. Luthans et al. (2004) also underline that “The rising recognition of human resources as a competitive advantage in today’s global economy, human capital and, more recently, social capital are being touted in both theory, research, and practice” (p.45). There are many different definitions of human and social capitals, concepts that are sometimes hard to measure but essential to success. Human capital is most often described by indicators such as age, gender, education and health, but there are other factors such as experience, different skills, knowledge and ideas which determine this capital. According to the World Economic Forum (2016), the top ten skills needed in 2020 will be: complex problem solving, critical thinking, creativity, people management, coordinating with others, emotional intelligence, judgement and decision making, service orientation, negotiation and cognitive flexibility. Social capital is defined as three strongly connected elements: trust, keeping norms and social relations built on transparency

Rate of complications due to neuromuscular scoliosis spine surgery in a 30-years consecutive series

PURPOSE: The aim of this study was to evaluate the rate of intraoperative and postoperative complications in a large series of patients affected by neuromuscular scoliosis. METHODS: It was a monocentric retrospective study. In this study have been considered complications those events that significantly affected the course of treatment, such as getting the hospital stay longer, or requiring a subsequent surgical procedure, or corrupting the final result of the treatment. RESULTS: Of the 358 patients affected by neuromuscular scoliosis treated from January 1985 to December 2010, 185 that met the inclusion criteria were included in the study. There were recorded 66 complications in 55/185 patients. Of that 66 complications, 54 complications occurred in 46/120 patients with Luque's instrumentation, while only 12 complications occurred in 9/65 patients with hybrid instrumentation and this difference was statistically significant (p 0.05). CONCLUSIONS: The surgical treatment in neuromuscular scoliosis is burdened by a large number of complications. An accurate knowledge of possible complications is mandatory to prepare strategies due to prevent adverse events. A difference in definitions could completely change results in good or bad as well as in our same series the adverse events amounted at almost 30% of cases, but complications that due to complete failure would amount at 9.19% of patients. KEYWORDS: Complications; Neuromuscular scoliosis; Scoliosis; Scoliosis surgery PMID: 28314995 DOI: 10.1007/s00586-017-5034-6 Share on FacebookShare on TwitterShare on Google

Chest pain caused by multiple exostoses of the ribs: A case report and a review of literature

Abstract The aim of this paper is to report an exceptional case of multiple internal exostoses of the ribs in a young patient affected by multiple hereditary exostoses (MHE) coming to our observation for chest pain as the only symptom of an intra-thoracic localization. A 16 years old patient with familiar history of MHE came to our observation complaining a left-sided chest pain. This pain had increased in the last months with no correlation to a traumatic event. The computed tomography (CT) scan revealed the presence of three exostoses located on the left third, fourth and sixth ribs, all protruding into the thoracic cavity, directly in contact with visceral pleura. Moreover, the apex of the one located on the sixth rib revealed to be only 12 mm away from pericardium. Patient underwent video-assisted thoracoscopy with an additional 4-cm mini toracotomy approach. At the last 1-year followup, patient was very satisfied and no signs of recurrence or major complication had occured. In conclusion, chest pain could be the only symptom of an intra-thoracic exostoses localization, possibly leading to serious complications. Thoracic localization in MHE must be suspected when patients complain chest pain. A chest CT scan is indicated to confirm exostoses and to clarify relationship with surrounding structures. Video-assisted thoracoscopic surgery can be considered a valuable option for exostoses removal, alone or in addiction to a mini-thoracotomy approach, in order to reduce thoracotomy morbidity

CALPHAD formalism for Portland clinker: thermodynamic models and databases

International audienceThe so-called CALPHAD method is widely used in metallurgy to predict phase diagrams of multi-component systems. The application of the method to oxide systems is much more recent, because of the difficulty of modelling the ionic liquid phase. Since the 1980s, several models have been proposed by various communities. Thermodynamic databases for oxides are available and still under development. The purpose of this article is to discuss the distinct approaches of the method for the calculation of multi-component systems for Portland cement elaboration. The article gives a state of the art of the most recent experimental data and the various calculations for the CaO-Al2O3-SiO2 phase diagram. A literature review of the three binary sub-systems leads to main conclusions: (i) discrepancies are found in the literature for the selected experimental data, (ii) the phase diagram data in the reference books are not complete and up to date and (iii) the two-sublattices model and the modified quasichemical model can be equally used for the modelling of the aluminates liquid. The predictive feature of the CALPHAD method is illustrated using the CaO-Al2O3-SiO2 system with the two-sublattices model: extrapolated (predicted) and fully-assessed phase diagrams are compared in the clinkering zone of interest. The recent application of the predictive method for the calculations of high-order systems (taking into account Fe2O3, SO3, CaF2, P2O5) shows that the databases developed with the two-sublattices model and the modified quasichemical model are no longer equivalent

SU-8 Guiding Layer for Love Wave Devices

SU-8 is a technologically important photoresist used extensively for the fabrication of microfluidics and MEMS, allowing high aspect ratio structures to be produced. In this work we report the use of SU-8 as a Love wave sensor guiding layer which allows the possibility of integrating a guiding layer with flow cell during fabrication. Devices were fabricated on ST-cut quartz substrates with a single-single finger design such that a surface skimming bulk wave (SSBW) at 97.4 MHz was excited. SU-8 polymer layers were successively built up by spin coating and spectra recorded at each stage; showing a frequency decrease with increasing guiding layer thickness. The insertion loss and frequency dependence as a function of guiding layer thickness was investigated over the first Love wave mode. Mass loading sensitivity of the resultant Love wave devices was investigated by deposition of multiple gold layers. Liquid sensing using these devices was also demonstrated; water-glycerol mixtures were used to demonstrate sensing of density-viscosity and the physical adsorption and removal of protein was also assessed using albumin and fibrinogen as model proteins

Domestic Animals of the Early Roman Period at Tell Hesban

Authored section of Heshbon Expedition report

In situ reactive capping for PAH-contaminated marine sediments: experimental investigations and numerical simulations

The distribution of contaminants in water bodies is a very complex topic due to several origins of pollution, with major concerns for human health and the environment. Several coastal-marine areas coexist with large industrial and port settlements that have led, over time, to compromise the whole marine ecosystem. In this context, the investigation of remediation strategies has given rise to great scientific and public concern throughout the world. The present thesis aims at evaluating the effectiveness of in situ reactive capping (ISC) technology and at investigating the best reactive material to reduce propagation of pollutants from marine sediments contaminated by polycyclic aromatic hydrocarbons (PAHs). Experimental activities were based on lab-scale batch column tests and aimed at assessing the performance of two reactive materials: • AquaGate®+5% of Powdered Activated Carbon (AG PAC), made of composite particles coated with bentonite and PAC; • Organophilic Clay Reactive Core Mat (OC RCM), a thin permeable composite mat with a layer of organophilic clay encapsulated between two geotextiles. The experimental activity has been carried out on contaminated marine sediments sampled from the Mar Piccolo of Taranto, Southern Italy, considered as a case study. The Mar Piccolo is a strongly anthropized environment, as a final receptor of a series of pollutants coming from all urban, industrial, and agricultural activities, municipal wastewater treatment plants, and other anthropic activities, especially due to its natural hydrogeological network conformation. A control column with no cap was also tested to investigate how pollutants behave and move through the sediment layer. After a first characterization, PAH concentrations in water were measured after 5, 10, and 20 days, while sediments were sampled after 20 days, at the end of the experiment. Benzo[a]pyrene, pyrene, and anthracene were chosen as target PAHs to be monitored as they were the most abundant pollutants in the sample. In the second step, a predictive model of the distribution of concentrations, in sediments and overlying water, was developed in order to evaluate the long-term effectiveness of the ISC intervention. A model was set up in COMSOL Multiphysics® where the physical-chemical properties measured during the experimental tests were considered as input values of the model. The basic equation describing the contaminant transport in one-dimensional porous media, over the time, was considered. The PAH fate and transport, through the multi-layered model to the upper water column, was predicted by considering the phenomena of diffusion, advection, and desorption in the sediments for all scenarios, and by adding the adsorption process in the two amendments tested, AG PAC and OC RCM. The design objective for the cap was to keep breakthrough concentrations of pollutants below the toxicity targets. The model was validated with the experimental values from the first phase. The results demonstrated a good effectiveness of both AG PAC and OC RCM for PAH contamination treatment over the time. The best performance, in terms of higher contamination reduction in the water column, was given by AquaGate®+5% PAC for the cases of benzo[a]pyrene and pyrene. Part of the experimental activities were funded in the framework of the Cooperation Agreement between the Special Commissioner of the Italian Government for urgent measures of remediation and environmental requalification of the Taranto area (south Italy) and the Polytechnic University of Bari