Puerto Colombia, Colombia
Puerto Colombia, Colombia

The Universidad del Norte is the main academic center for higher education in northern Colombia. It was founded in 1966 by a group of businessmen led by Karl C. Parrish in the city of Barranquilla. It started its academic operation on July 11, 1966, with 58 students and 10 teachers on core courses of business administration and engineering.According to a recent ranking of the best universities of Colombia the "Universidad del Norte" is one of the 5 best ones of Colombia.The university is composed of 8 academic divisions: Engineering, Administrative science, Humanities and Social science, Health science, Legal science and the Basic science division, as well as the Institute of Superior Studies in Education.The university offers careers in industrial, mechanical, computer, civil, electrical and electronic engineering, as well as Medicine, Business Administration, Law, Psychology, International Relations, International Business, Math, Industrial Design, Graphic Design, Architecture, and several other faculties. In total, the university offers 22 undergraduate programs, 69 professional specialization programs, 37 Master's programs, and 6 doctoral programs. The University also offers some specialization programs in Santa Marta. All of the engineering programs were accredited by the ABET, which is one of the most important international accreditation agencies, located in Baltimore, United States.It is one of the most important cultural and technological centers on the Caribbean region of Colombia. Wikipedia.

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Alonso E.E.,Polytechnic University of Catalonia | Berdugo I.R.,Universidad del Norte, Colombia | Ramon A.,Polytechnic University of Catalonia
Geotechnique | Year: 2013

The paper describes the expansive phenomena affecting Lilla tunnel in Spain during construction and subsequent operation. The geology of the site and the performance of alternative support designs are described. Field observations are analysed to identify the causes of the observed swelling. It was found that long-term swelling in Lilla tunnel was the result of gypsum crystal growth in discontinuities. The phenomenon was a consequence of a few contributing factors: significant presence of anhydrite, existent or activated discontinuities, and the circulation of water. These conditions were present in the highly tectonised Tertiary claystone in Lilla. The original horseshoe cross-section was transformed into a circular one, and a reinforced concrete lining was built to resist swelling pressures. Long-term monitoring of the reinforced tunnel provided valuable data on the evolution of swelling pressures against the lining, and on the stresses developed in the resisting structure. The highly heterogeneous distribution of swelling pressures against the lining explains the low strains measured in reinforcement bars despite the very high maximum swelling pressures recorded.

Hernandez R.J.,Universidad del Norte, Colombia | Fahrenthold E.P.,University of Texas at Austin
International Journal for Numerical Methods in Engineering | Year: 2013

Hamiltonian models of high-velocity impact dynamics, based on a hybrid particle-element kinematic scheme, offer an energy conserving description of general contact-impact, perforation, and fragmentation physics with applications in a number of important engineering fields. Published work on these models has considered only a uniform finite element mesh, requiring curved surfaces and many target and projectile geometries to be represented in an approximate fashion. In recent research, the authors have developed a new formulation suitable for application to any solid model described by an unstructured hexahedral mesh. The formulation incorporates a new algorithm, which constructs an ellipsoidal particle discretization of the mass distribution described by a general hex mesh and a new density interpolation suitable for use with general ellipsoidal arrays whose particles vary in mass, shape, and spatial orientation. Application of the method in the simulation of high-velocity impact problems shows good agreement with experiment, for both smoothly graded and deliberately distorted hexahedral meshes. © 2013 John Wiley & Sons, Ltd.

Guzman J.D.,Universidad del Norte, Colombia
Molecules | Year: 2014

Antimicrobial natural preparations involving cinnamon, storax and propolis have been long used topically for treating infections. Cinnamic acids and related molecules are partly responsible for the therapeutic effects observed in these preparations. Most of the cinnamic acids, their esters, amides, aldehydes and alcohols, show significant growth inhibition against one or several bacterial and fungal species. Of particular interest is the potent antitubercular activity observed for some of these cinnamic derivatives, which may be amenable as future drugs for treating tuberculosis. This review intends to summarize the literature data on the antimicrobial activity of the natural cinnamic acids and related derivatives. In addition, selected hybrids between cinnamic acids and biologically active scaffolds with antimicrobial activity were also included. A comprehensive literature search was performed collating the minimum inhibitory concentration (MIC) of each cinnamic acid or derivative against the reported microorganisms. The MIC data allows the relative comparison between series of molecules and the derivation of structure-activity relationships. © 2014 by the authors; licensee MDPI, Basel, Switzerland.

Ortiz Royero J.C.,Universidad del Norte, Colombia
Natural Hazards | Year: 2012

An analysis of the exposure of the Colombian Caribbean coast to the effect of tropical storms and hurricanes was conducted using historical records from between 1900 and 2010. The Colombian Caribbean coast is approximately 1,760 km long, and the main coastal cities in this important region are Riohacha (RIO), Santa Marta (STA), Barranquilla (BAQ), and Cartagena (CTG). The surface extension of the Colombian Caribbean is almost 590,000 km 2. The cumulative number of events was used to determine the exposure and to identify the most vulnerable zones on the continental coast of Colombia and in the country's insular Caribbean. Although the Colombian Caribbean coast is not registered as a potentially vulnerable zone in international databases, there have been significant events in the region, some of which even hit land. The results show that the island of San Andrés (SA) and the Department of Guajira are the zones most likely to be affected by storms in the Colombian Caribbean. Hurricane Joan in October of 1988 has been the most devastating event in the history of hurricanes in Colombian waters. © 2011 Springer Science+Business Media B.V.

Reuter M.,University of Mainz | Tuiran E.,Universidad del Norte, Colombia
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

We analyze the impact of the leading quantum gravity effects on the properties of black holes with nonzero angular momentum by performing a suitable renormalization group improvement of the classical Kerr metric within quantum Einstein gravity. In particular, we explore the structure of the horizons, the ergosphere, and the static limit surfaces as well as the phase space available for the Penrose process. The positivity properties of the effective vacuum energy-momentum tensor are also discussed and the "dressing" of the black hole's mass and angular momentum are investigated by computing the corresponding Komar integrals. The pertinent Smarr formula turns out to retain its classical form. As for their thermodynamical properties, a modified first law of black-hole thermodynamics is found to be satisfied by the improved black holes (to second order in the angular momentum); the corresponding Bekenstein-Hawking temperature is not proportional to the surface gravity. © 2011 American Physical Society.

Batra R.C.,Virginia Polytechnic Institute and State University | Pacheco A.A.,Universidad del Norte, Colombia
Acta Materialia | Year: 2010

We use molecular statics simulations with the tight-binding potential to analyze stress evolution in nanosize square prismatic gold specimens of different aspect ratios (length/width) deformed in either simple tension/compression or tension/compression. In the former case atoms on end faces are displaced axially but are free to move laterally, and in the latter case atoms on end faces are restrained from moving laterally during their axial displacement. It is found that the stress distribution in the unloaded reference configuration is non-uniform, and it satisfies the local and the global equilibrium equations. Large values of the von Mises stress and the maximum shear stress occur on atoms located at the third layer beneath the traction free surfaces forming different patterns for specimens loaded in tension and compression. The specimen is assumed to yield when its total strain energy drops noticeably. Maximum values of the von Mises stress and the maximum shear stress at yielding are essentially independent of specimen's length for specimens deformed in tension. For specimens deformed in compression, wave-like patterns of stresses along the axial centroidal axis are observed when the specimen yields. © 2010 Acta Materialia Inc.

Nino E.D.,Universidad del Norte, Colombia
International Journal of Artificial Intelligence | Year: 2012

This paper states two novel algorithms based on the Automata Theory for the Multiobjective Optimization of Combinatorial Problems. The first algorithm proposed is named SAMODS. It is a hybrid Simulated Annealing MODS inspired algorithm. The main idea behind this approach consists in optimizing a Combinatorial Problem changing the Angle Improvement; this is a novel theory maintain in the classic weighted sum metric. SAMODS avoids unfeasible solutions fall back on the MODS theory. Also, it avoids local optimum due to the use of Boltzmann Distribution Probability for accepting bad solutions as good solutions. The last proposed algorithm was named SAGAMODS. It is an Evolutionary Algorithm based on the MODS theory. In addition to the advantages of SAMODS, SAGAMODS avoids in two times local optimums because of its Crossover Step. It is taken from the Natural Selection Theory that allows creating new solutions (next generation) support in the current solutions (actual generation). Only the best solutions survive. The proposed algorithms were tested using instances from the well-known TSPLIB. The test was made using problems with two objectives, three objectives, four objectives and five objectives inclusive. The proposed algorithms were compared using metrics from the specialized literature of the Multiobjective Optimization. The results of the metrics applied to the algorithms shows that MODS algorithm was superseded up to 100% out of 100%, in some of the instances worked, by the proposed algorithms. © 2012 by IJAI (CESER Publications).

de la Cruz J.,Universidad del Norte, Colombia
Designs, Codes, and Cryptography | Year: 2015

We prove that the only primes which may divide the order of the automorphism group of a putative binary self-dual doubly-even (Formula presented.) code are (Formula presented.) and (Formula presented.). Furthermore we prove that automorphisms of prime order (Formula presented.) have a unique cycle structure. Parts of the results are based on computer computations. © 2013, Springer Science+Business Media New York.

Escorcia V.,Universidad del Norte, Colombia | Niebles J.C.,Universidad del Norte, Colombia
Proceedings of the IEEE International Conference on Computer Vision | Year: 2013

We introduce a new method for representing the dynamics of human-object interactions in videos. Previous algorithms tend to focus on modeling the spatial relationships between objects and actors, but ignore the evolving nature of this relationship through time. Our algorithm captures the dynamic nature of human-object interactions by modeling how these patterns evolve with respect to time. Our experiments show that encoding such temporal evolution is crucial for correctly discriminating human actions that involve similar objects and spatial human-object relationships, but only differ on the temporal aspect of the interaction, e.g. answer phone and dial phone We validate our approach on two human activity datasets and show performance improvements over competing state-of-the-art representations. © 2013 IEEE.

Hernandez J.J.,University of Castilla - La Mancha | Aranda-Almansa G.,University of Castilla - La Mancha | Bula A.,Universidad del Norte, Colombia
Fuel Processing Technology | Year: 2010

Experimental tests in an entrained flow gasifier have been carried out in order to evaluate the effect of the biomass particle size and the space residence time on the gasifier performance and the producer gas quality. Three types of biomass fuels (grapevine pruning and sawdust wastes, and marc of grape) and a fossil fuel (a coal-coke blend) have been tested. The results obtained show that a reduction in the fuel particle size leads to a significant improvement in the gasification parameters. The thermochemical characterisation of the resulting char-ash residue shows a sharp increase in the fuel conversion for particles below 1 mm diameter, which could be adequate to be used in conventional entrained flow gasifiers. Significant differences in the thermochemical behaviour of the biomass fuels and the coal-coke blend have been found, especially in the evolution of the H2/CO ratio with the space time, mainly due to the catalytic effect of the coal-coke ash. The reaction temperature and the space time have a significant effect on the H2/CO ratio (the relative importance of each of these parameters depending on the temperature), this value being independent of the fuel particle size. © 2010 Elsevier B.V. All rights reserved.

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