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Search Results: 1 - 10 of 4078 matches for " Federico; Mercado "
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El patrimonio arqueológico frente a las obras de trazado lineal: Caso gasoducto y CTCC Salta Termoandes S.A. (Cobos, Gral. Guemes, Salta)
Soria,Silvia; Vitry,Christian; Santoni,Mirta; Mulvany,Eleonora; Viveros,Federico; Mercado,Antonio; Mamaní,Mabel;
Cuadernos de la Facultad de Humanidades y Ciencias Sociales. Universidad Nacional de Jujuy , 2002,
Abstract: in the process of the construction of the salta termoandes thermoelectrical power station s.a. and its feeding gas pipe, we participate in one of the instances of the environmental impact studies and in an archaeological rescue. as a consequence of this experience, we present the results obtained, which include methodological aspects and the interpretation of the archaeological record localized and rescued. we, as professionals, should cover the necessities of the management of our archaeological heritage. in this direction, we should make an effort to adequate theory, methodology and technology in the solution of practical problems involved in all the stages of the e.i.s. we suggest the formation, in an academic level, of specialists who could develop both basic research and managment of archaeological resources.
How gravity and size affect the acceleration statistics of bubbles in turbulence
Vivek N. Prakash,Yoshiyuki Tagawa,Enrico Calzavarini,Julian Martinez Mercado,Federico Toschi,Detlef Lohse,Chao Sun
Physics , 2012, DOI: 10.1088/1367-2630/14/10/105017
Abstract: We report results from the first systematic Lagrangian experimental investigation in the regime of very light (air bubbles in water) and large particles (D/{\eta} >> 1) in turbulence. Using a traversing camera setup and particle tracking, we study the Lagrangian acceleration statistics of ~3 mm diameter (D) bubbles in a water tunnel with nearly homogeneous and isotropic turbulence generated by an active-grid. The Reynolds number (Re_{\lambda}) is varied from 145 to 230, resulting in size ratios, D/{\eta} in the range of 7.3--12.5, where {\eta} is the Kolmogorov length scale. The experiments reveal that gravity increases the acceleration variance and reduces the intermittency of the PDF in the vertical direction. Once the gravity offset is subtracted, the variances of both the horizontal and vertical acceleration components are about 5\pm2 times larger than the one measured in the same flow for fluid tracers. Moreover, for these light particles, the experimental acceleration PDF shows a substantial reduction in intermittency at growing size ratios, in contrast to neutrally buoyant or heavy particles. All these results are closely matched by numerical simulations of finite-size bubbles with the Fax\'en corrections.
A General Purpose Analysis Package  [PDF]
Stefano Federico
Atmospheric and Climate Sciences (ACS) , 2012, DOI: 10.4236/acs.2012.22022
Abstract: This paper presents a general-purpose analysis package able to solve two- and three- dimensional analysis problems. The system can use the following methods of solution: Successive Approximation (SA), Optimal Interpolation (OI), and 3D-Var. Analyses are given for the following parameters: zonal and meridional wind components, temperature, relative humidity, and geopotential height. The analysis package was applied to produce analyses at 6 h time interval for the period 1-11 August 2008. The period was selected for data availability and forty-one analyses were collected. The results show the validity of the different solutions, which can be chosen depending on the physical problem to solve and on the computational resources available. In particular, assuming the observations as the reference, all solutions show a decrease of the RMSE compared to the background. The decrease is consistent with the particular setting of the analysis system used in this paper. The comparison between different solutions shows that the SA converges to OI in few iterations, and that the SA solution with ten iteration is, in practice, equal to OI. Moreover, the 3D-Var method shows its potential to improve the analysis, once the horizontal and vertical length-scales and the background and observational errors are set optimally, because its solution may be sizeably different from two-dimensional methods.
Emerging Trends and Old Habits in Higher Education Management: Focus on the Public vs. Private Funding Debate  [PDF]
Federico Barnabè
Creative Education (CE) , 2012, DOI: 10.4236/ce.2012.326152
Abstract: This work takes into consideration the wide reform process that is impacting on Universities all over the world, especially focusing on the public versus private funding debate for Higher Education Institutions. In this regard, the paper provides some considerations on possible funding sources, discusses data related to the relevance of public funding and presents the features of the main models of public funding across many countries, particularly focusing on Europe.
Preliminary Results of a Data Assimilation System  [PDF]
Stefano Federico
Atmospheric and Climate Sciences (ACS) , 2013, DOI: 10.4236/acs.2013.31009

A data assimilation system combines all available information on the atmospheric state in a given time-window to produce an estimate of atmospheric conditions valid at a prescribed analysis time. Nowadays, increased computing power coupled with greater access to real-time asynoptic data is paving the way toward a new generation of high-resolution (i.e. on the order of 10 km) operational mesoscale analyses and forecasting systems. Moreover, better initial conditions are increasingly considered of the utmost importance for Numerical Weather Prediction (NWP) at the short range (0 - 12 h). This paper presents a general-purpose data assimilation system, which is coupled with the Regional Atmospheric Modelling System (RAMS) to give the analyses for: zonal and meridional wind components, temperature, relative humidity, and geopotential height. In order to show its potential, the data assimilation systems applied to produce analyses over Central Europe. For this application the background field is given by a short-range forecast (12 h) of the RAMS and analyses are produced by 2D-Var with 0.25? horizontal resolution. Results show the validity of the analyses because they are closer to the observations, consistently with the settings of the data assimilation system. To quantify the impact of improved initial conditions on the forecast, the analyses are then used as initial conditions of a short-range (6 h) forecast of the RAMS model. The results show that the RMSE is effectively reduced for the one- and two hours forecast, with some improvement for the three-hours forecast.

Photovoltaic Prickle Pear Harvesting Tool  [PDF]
Federico Hahn
Natural Resources (NR) , 2013, DOI: 10.4236/nr.2013.43033

Mexico is the largest cactus exporter of the world and 40% of the production cost is provided from the harvest operation. Many workers are required to operate daily and suffer wrist pain after two weeks of collecting pears with mechanical pruners. A motor driven tool supplied from a photovoltaic system was employed for harvesting; different blades were tested at different cutting speeds. It was found that toothed blades sliced the pears with efficiencies over 90%. Abrasive blades were finally selected as the current required per cut was minimum, permitting a longer battery lifetime before requiring recharging.

One Dimensional Relativistic Particle in a Quadratic Dissipative Medium Subjected to a Force That Depends on the Position  [PDF]
Federico Petrovich
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.69122
Abstract: We will find a constant of motion with energy units for a relativistic particle moving in a quadratic dissipative medium subjected to a force which depends on the position. Then, we will find the Lagrangian and the Hamiltonian of the equation of motion in a time interval such that the velocity does not change its sign. Finally, we will see that the Lagrangian and Hamiltonian have some problems.
A New Formulation of Classical Mechanics—Part 1  [PDF]
Federico Petrovich
Journal of Applied Mathematics and Physics (JAMP) , 2016, DOI: 10.4236/jamp.2016.42048
Abstract: This paper has two parts, in this occasion we will present the first one. Until today, there are two formulations of classical mechanics. The first one is based on the Newton’s laws and the second one is based on the principle of least action. In this paper, we will find a third formulation that is totally different and has some advantages in comparison with the other two formulations.
A New Formulation of Classical Mechanics—Part 2  [PDF]
Federico Petrovich
Journal of Applied Mathematics and Physics (JAMP) , 2016, DOI: 10.4236/jamp.2016.45103
Abstract: In the first part of this paper, we found a more convenient algorithm for solving the equation of motion of a system of n bodies. This algorithm consists in solving first the trajectory equation and then the temporal equation. In this occasion, we will introduce a new way to solve the temporal equation by curving the horizontal axis (the time axis). In this way, we will be able to see the period of some periodic systems as the length of a certain curve and this will allow us to approximate the period in a different way. We will also be able to solve some problems like the pendulum one without using elliptic integrals. Finally, we will solve Kepler’s problem using all the formalism.
Enfermedades metabólicas óseas: análisis clínico y radiológico en cinco casos
Ochoa,Carlos Darío; Toro,Carlos E; Ramírez,Fabián; Mercado,Jaime; Olivares,Orlando; Restrepo,José Félix; Rondón,Federico; Iglesias-Gamarra,Antonio;
Revista Colombiana de Reumatología , 2010,
Abstract: the study of metabolic bone disease is broad and complex. the most widely recognized bone disease by physicians of all specialties is osteoporosis, probably due to its high frequency. however, it is important to recognize that there are numerous entities that affect bone metabolism in different ways, leading to brittle bones, increased risk of fracture, osteoporosis or osteocondensation, according to each particular case. both the clinical diagnosis and recognition of the underlying metabolic abnormality are important because they identify the specific abnormality that will be the base for treatment. there were 5 different cases in which a metabolic disorder leads to specific bone pathology, we discuss the pathogenesis of arterial calcifications and presents a mixed entity we call osteoporomalacia.
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