Universidad del Norte, Colombia

About: Universidad del Norte, Colombia is a education organization based out in Barranquilla, Colombia. It is known for research contribution in the topics: Population & Context (language use). The organization has 3562 authors who have published 4355 publications receiving 37861 citations. The organization is also known as: University of the North, Colombia & Uninorte.

Contribution of low-frequency climatic–oceanic oscillations to streamflow variability in small, coastal rivers of the Sierra Nevada de Santa Marta (Colombia)

Abstract: . This study evaluated the influence of low-frequency oscillations, that are linked to large-scale oceanographic–atmospheric processes, on streamflow variability in small tropical coastal mountain rivers of the Sierra Nevada de Santa Marta, Colombia. We used data from six rivers that had > 32 years of complete, continuous monthly streamflow records. This investigation employed spectral analyses to (1) explore temporal characteristics of streamflow variability, (2) estimate the net contribution to the energy spectrum of low-frequency oscillations to streamflow anomalies, and (3) analyze the linkages between streamflow anomalies and large-scale, low-frequency oceanographic–atmospheric processes. Wavelet analyses indicate that the 8–12-year component exhibited a quasi-stationary state, with a peak of maximum power between 1985 and 2005. These oscillations were nearly in phase in all rivers. Maximum power peaks occurred for the Palomino and Rancheria rivers in 1985 and 1995, respectively. The wavelet spectrum highlights a change in river variability patterns between 1995 and 2015, characterized by a shift towards the low-frequency oscillations' domain (8–12 years). The net contribution of these oscillations to the energy spectrum was as high as 51 %, a value much larger than previously thought for rivers in northwestern South America. The simultaneous occurrence of hydrologic oscillations, as well as the increase in the amplitude of the 8–12-year band, defined periods of extremely anomalous wet seasons during 1989–1990, 1998–2002 and 2010–2011, reflecting the role of low-frequency oscillations in modulating streamflow variability in these rivers. Cross-wavelet transform and wavelet coherence revealed high common powers and significant coherences in low-frequency bands ( >96 months) between streamflow anomalies and Atlantic Meridional Oscillation (AMO), Pacific Decadal Oscillation (PDO) and the Tropical North Atlantic Index (TNA). These results show the role of large-scale, low-frequency oceanographic–climate processes in modulating the long-term hydrological variability of these rivers.

The pre-Columbian dog from Arica, Chile

Abstract: Burials and mummies of dogs from the Arica, Chile, area are described. It is concluded that these dogs were brought to this area 2500 years ago by shepherds from the highlands and are still present, relatively unchanged. Eight mummies of dogs with the hair pre- sent were studied. The cultures from which they came are known and carbon-14 dates were obtained from human mummies in the ceme- teries where the dogs were found. Additional skeletal material was available but was not included in these studies except to note that these skeletons were similar to the mummies when compared with radiographs of the latter. One ceramic of a dog was also studied, the only such ceramic seen in over 30 years of exca- vating in this zone. Petroglyphs (stone carv- ings) and geoglyphs (pictures made by placing stones) in the Arica area were also examined for figures that might possibly represent dogs. RESULTS Geoglyphs and petroglyphs were examined in the valleys of Azapa, Camarones, Lluta, and Codpa, all in the Arica area. Petroglyphs of dogs were seen in the Azapa valley at Livicar near the parking area for the fiesta of the Vir- gen de las Pefias. The dogs were associated with human figures, and cameloids. A fox was also seen and could easily be distinguished from the dogs by his bushy tail. In the lower part of the Azapa valley near Cerro Sombrero were geoglyphs that also show human figures and cameloids in association with a dog. The valley of Codpa had foxes as well as dogs in the pe- troglyphs from Olagia, in Camerones dogs were also noted at Taltape.

Modelación y simulación computacional de un proceso productivo de una pequeña empresa usando dinámica de sistemas

Abstract: Este articulo pretende motivar a los estamentos academicos y a las pequenas y medianas organizaciones a desarrollar en el area de la simulacion dinamica de sistemas trabajos conjuntos que conlleven a un direccionamiento empresarial mas claro y confiable, y de paso contribuyan a la formacion de profesionales mejor capacitados para satisfacer las necesidades del medio. Para ello se presenta la aplicacion de la simulacion dinamica de sistemas en una pequena empresa, mediante la modelacion y simulacion computacional del proceso de plastificado de barra metalica para carpetas de FRAMECO S.A (Bello-Antioquia), con interes particular en la identificacion de las limitaciones del sistema, la capacidad de produccion, el tiempo tipo del proceso, el tiempo ocioso de la mano de obra y el tiempo de consumo innecesario del gas empleado como insumo en uno de los equipos; igualmente, se ilustra de manera general el analisis de sensibilidad del proceso. Como resultado se obtiene un modelo de simulacion que representa de manera razonable el comportamiento dinamico del proceso y le facilita al directivo, academico o analista, la comprension, el analisis y el mejoramiento del sistema productivo.

Viscoelastic modelling of an asphalt pavement based on actual tire-pavement contact pressure

Abstract: A three-dimensional finite element (3-D FE) modelling was conducted based on non-uniform distributed tire-pavement contact pressure, full interfacial layer bonding conditions, and viscoelastic char...