1,721,485 research outputs found
Spanish sources concerning the 1693 earthquake in Sicily
No full textWhen the great 1693 earthquake occurred, Sicily was a viceroyalty of Spain. In order to find primary and direct
sources, the Archivo General de Simancas has to be investigated. Due to the lack of extensive and adequate
catalogues it is difficult search amongst the millions of documents filed there. The author located
among numerous bundles of papers of different Sections. a total of 238 manuscripts (with 850 pages) and
4 printed edicts related to the 1693 earthquake. All the gathered information offers good prospects of true
knowledge on many aspects related to the seismic catastrophe: perception area. number of victims, ruin of
towns, list of aftershocks. reconstruction. health and public order problems, and all those problems that surround
a great historic earthquake (economic, political, social and religious).JCR Journalope
Spanish sources concerning the 1693 earthquake in Sicily
No full textWhen the great 1693 earthquake occurred, Sicily was a viceroyalty of Spain. In order to find primary and direct sources, the Archivo General de Simancas has to be investigated. Due to the lack of extensive and adequate catalogues it is difficult search amongst the millions of documents filed there. The author located among numerous bundles of papers of different Sections. a total of 238 manuscripts (with 850 pages) and 4 printed edicts related to the 1693 earthquake. All the gathered information offers good prospects of true knowledge on many aspects related to the seismic catastrophe: perception area. number of victims, ruin of towns, list of aftershocks. reconstruction. health and public order problems, and all those problems that surround a great historic earthquake (economic, political, social and religious)
Predictors for anastomotic leak, postoperative complications, and mortality after right colectomy for cancer. Results from an international snapshot audit
No full textBACKGROUND: A right hemicolectomy is among the most commonly performed operations for colon cancer, but modern high-quality, multination data addressing the morbidity and mortality rates are lacking. OBJECTIVE: This study reports the morbidity and mortality rates for right-sided colon cancer and identifies predictors for unfavorable short-term outcome after right hemicolectomy. DESIGN: This was a snapshot observational prospective study. SETTING: The study was conducted as a multicenter international study. PATIENTS: The 2015 European Society of Coloproctology snapshot study was a prospective multicenter international series that included all patients undergoing elective or emergency right hemicolectomy or ileocecal resection over a 2-month period in early 2015. This is a subanalysis of the colon cancer cohort of patients. MAIN OUTCOME MEASURES: Predictors for anastomotic leak and 30-day postoperative morbidity and mortality were assessed using multivariable mixed-effect logistic regression models after variables selection with the Lasso method. RESULTS: Of the 2515 included patients, an anastomosis was performed in 97.2% (n = 2444), handsewn in 38.5% (n = 940) and stapled in 61.5% (n = 1504) cases. The overall anastomotic leak rate was 7.4% (180/2444), 30-day morbidity was 38.0% (n = 956), and mortality was 2.6% (n = 66). Patients with anastomotic leak had a significantly increased mortality rate (10.6% vs 1.6% no-leak patients; p > 0.001). At multivariable analysis the following variables were associated with anastomotic leak: longer duration of surgery (OR = 1.007 per min; p = 0.0037), open approach (OR = 1.9; p = 0.0037), and stapled anastomosis (OR = 1.5; p = 0.041). LIMITATIONS: This is an observational study, and therefore selection bias could be present. For this reason, a multivariable logistic regression model was performed, trying to correct possible confounding factors. CONCLUSIONS: Anastomotic leak after oncologic right hemicolectomy is a frequent complication, and it is associated with increased mortality. The key contributing surgical factors for anastomotic leak were anastomotic technique, surgical approach, and duration of surgery
Blanda, Laos, Cerillae : guida archeologica dell'alto Tirreno cosentino / Emanuele Greco, Gioacchino Francesco La Torre
No full textCorrection to: The Italian version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR)
Full text linkThe family name of author Francesco La Torre was incorrect in the published article. The correct family name should read as La Torre F
Evaluation of mechanical performance of cement–bitumen-treated materials through laboratory and in-situ testing
No full textNowadays, cold recycling is considered as a common road construction/maintenance technique
and no longer as an alternative technique to the traditional ones. The difficulties in
simulating the production and construction processes in laboratory have led researchers to
practise full-scale testing of mixtures. This paper presents a comprehensive evaluation of the
mechanical performance of a cement–bitumen-treated materials (CBTMs) containing 80% of
reclaimed asphalt. After a preliminary mix design, the mixture was produced in a mix plant
and laid down on two trial sections with different layer thicknesses (15 and 20 cm) over a
homogeneous subgrade. The mixture was sampled before laying, compacted and characterised
through indirect tensile test and indirect tensile stiffness modulus test. The same tests were carried
out on cores taken from the trial sections. Light weight deflectometer and falling weight
deflectometer surveys were performed on the trial sections to evaluate the performances of the
CBTMs
Gas flow in miniaturized nozzles for micro-thrusters
No full textA new satellite philosophy, developed during the last two decades, suggests to make satellites smaller and lighter rather than bigger and heavier. In other words, large (?m3), single system satellites are being replaced by ?eets of small (?dm3), so-called micro-satellites. Future developmentsmay result in swarms ofmicro satellites ?ying through space in formation. Together they would perform the same tasks as a single large satellite, but with great savings in costs, increased simplicity, less vulnerability, and better replicability. As part of this new generation of (micro-)satellites, in order to provide highly precise station keeping, altitude control or long duration low thrust acceleration, new propulsion systems with thrusts in the ¹N to mN range need to be developed. One of the simplest forms ofmicro propulsion systems is a cold gas thruster: here, the energy stored in a pressurized gas is converted into kinetic energy through an expansion. The ef?ciency of such devices is strongly geometry and size dependent. Moreover, due to their small dimensions, combined with the low exhaust pressures in space, these systems behave differently than conventional large scale nozzles. Whereas experimental studies of micro propulsion systems are time consuming, dif?cult to perform with suf?cient accuracy, and require expensive experimental setups, numerical computer simulations can be a powerful tool of investigation. This thesis deals with the use and, where needed, the optimum combination of different numerical simulation models for the computational design of micro-thrusters, aimed at optimizing their performance and understanding the physics of the ?ow in such systems. In the ?rst phase of this work, we developed and used models for the design and optimization of micro thrusters providing a thrust in the mN range, as being developed for the actual state-of-the-art in micro propulsion system design. It was shown that conventional continuum Computational Fluid Dynamics can be used to study the gas ?ow and pressure distribution in such these micro-nozzles. Computationally predicted thrusts were in good agreement with experimental data. For mN thruster micro nozzles, in deviation from conventional large (kN-MN) thruster nozzles, viscous effects cannot be neglected due to the largely increased surface-to-volume ratio. As a result, ef?ciency loss due to developing viscous boundary layers, as well as surface roughness, are two main areas of concern in micro nozzles. Viscous losses were found to lead to an ef?ciency decrease of about 10%. Wall roughness added an extra 10% in ef?ciency loss. The increased boundary layer thickness reduced the effective cross sectional area of the divergent part of the nozzle. As a consequence it was found that, for optimum performance, micro nozzles should have a larger divergent angle than common in large scale nozzles. When the dimensions of micro-nozzles are further reduced, towards thrusts in the order of ¹N’s, the gas in the nozzle, particularly in its divergent part, becomes rare?ed. Under these conditions continuum based Computational Fluid Dynamics no longer provides an accurate description of ?ows and pressures, and non-continuum models should be used instead. Direct Simulation Monte Carlo was selected as the simulation method of choice for these conditions, because of its favorable combination of accuracy, ?exibility and computational costs compared to other available methods. Nevertheless, DSMC simulations are extremely more expensive than CFD simulations, particularly for weakly rare?ed gases. A possible solution lies in the application of a hybrid CFD/DSMC approach, where CFD is applied in those regions where rarefaction is not important, and DSMC is used in those regions where rarefaction needs to be accounted for. One of the main challenges faced in the second phase of this project was therefore in the consistent and ef?cient coupling of DSMC and CFD, making use of an existing general purpose CFD code and an existing general purpose DSMC code. The general idea was to apply continuum CFD in the upstream, high pressure convergent part of the nozzle, and use the CFD results as boundary condition for DSMC simulations in the downstream, low pressure divergent part of the nozzle. A detailed analysis of the numerical accuracy and computational costs of such a hybrid approach was carried out by comparing the results to those of, extremely costly, full DSMC simulations. Both accuracy and computational costswere found to critically depend on the chosen location of the interface between the CFD and DSMC regions, at which data is transferred from the ?rst to the latter. Rather than locating this interface at the throat, as is common in literature, we provide a simple recipe for the a priori determination of the optimal interface location. In this way, we were able to ?nd an optimum combination between accuracy and costs, leading to results that deviate less than 2% from full DSMC simulations at typically 5-25% of the computational costs of full DSMC. Finally, combining the three computational approachesmentioned above,we were able to produce master curves for the performance of micro nozzles as a function of the gas-wall collision accommodation coef?cient, over a wide range of nominal thrusts from O(10N) down to O(0.1¹N). For thrusts larger than 1mN, ef?ciencies larger than 90% were found, independent of the accommodation coef?cient. For smaller thrusts, the ef?ciency becomes strongly dependent on the accommodation coef?cient, i.e. on the nature of gas-wall collisions, and drops to 50% for thrusters in the ¹Nrangewith accommodation coef?cients equal to one. By reducing this accommodation coef?cient to a value below 0.5, which may be achieved by a proper selection of nozzle wall material and nozzle fabrication technique in combination with the proper choice of gas, this ef?ciency may be increased up to 70-80%. This thesis has resulted in: (i) design rules for micro thruster nozzles, (ii) computation methods that can be used in their design and evaluation, and (iii) in master ef?ciency curves that relate their nominal thrust and material properties to their thruster ef?ciency.Multi-Scale PhysicsApplied Science
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