Investigation of the effect of contact pattern design on the mechanical and thermal behaviors of plastic-steel helical gear drives

This article describes an investigation that has been conducted to assess the effects of the contact pattern design on the mechanical and thermal behaviors of plastic-steel helical gear drives. The maximum contact pressure, frictional power loss, transmission error function and operating temperature are determined for different designs of the pinion tooth surfaces. Several numerical examples based on loaded tooth contact analyses and steady-state heat transfer analyses are carried out considering different types of micro-geometry modifications of the involute tooth surfaces. The obtained results show that an appropriate design of the pinion tooth surfaces can help reducing the maximum contact pressure and the maximum operating temperature, increasing the durability of the transmission. The frictional power loss and the peak-to-peak transmission error can be diminished, improving the performance of the transmission and increasing its efficiency. Also, it has been shown that the design of the pinion tooth surfaces can provide some capability to the transmission to absorb angular misalignments.Funding for open access charge: CRUE-Universitat Jaume

New records of Pristidactylus nigroiugulus Cei, Scolaro & Videla, 2001 (squamata: Leiosauridae) with a geographic distribution map

We provide new geographic records for Pristidactylus nigroiugulus Cei, Scolaro & Videla, 2001 from Argentina. We present the first record for Santa Cruz province and the southernmost records of the species based on lizards collected in the austral summers of 2012/2013 and 2013/2014. Based on a museum specimen, we extend the species distribution to the eastern part of the Somuncurá Plateau. An updated distributional map is included.Fil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Minoli, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Perez, Cristian Hernan Fulvio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Gonzalez Marin, Maria Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Morando, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentin

Circumnuclear structure and kinematics in the active galaxy NGC 6951

A study is presented of the central structure and kinematics of the galaxy NGC 6951, by means of broad band B'IJK images and high resolution high dispersion longslit spectroscopy, together with archival HST WFPC2 V and NICMOS2 J and H images. We find that there is evidence of two modes of star formation, in bursts and continuously. The equivalent width of the CaII triplet absorption lines show that, in the metal rich central region, the continuum is dominated by a population of red supergiants. The gaseous and stellar kinematics along three slit position angles, suggest the existence of a hierarchy of disks within disks, whose dynamics are decoupled at the two ILRs, that we find at 180 pc and at 1100 pc. This is supported by the structure seen in the high resolution HST images. The nucleus is spatially resolved within a radius of 1.5 arcsec, just inside the innermost ILR. Outside the iILR, the stellar CaT velocity profile is resolved into two components, associated with the bar and the disk. Several results indicate that this is a dynamically old system. It is thus possible that a nuclear bar has existed in NGC 6951 that drove the gas towards the nucleus, as in the bars within bars scenario, but that this bar has already dissolved by the gas accumulated within the circumnuclear region. We discuss the possibility that the kinematical component inside the iILR could be due to a nuclear outflow produced by the combined effects of SN and SN remnants, or to a nuclear disk, as in the disk within disk scenario that we propose for the fueling of the AGN in NGC 6951.Comment: 14 pages, 16 figures. Accepted for publication in Astronomy and Astrophysics. High resolution images in http://www.iaa.es/~eperez/research/degas.htm

Design of Gear Drives With High Gear Ratio

A three part paper to describe the results of several gear drive types with a high gear ratio is presented. A single stage planetary gear train with double helical gears is described with methods to reduce transmission errors and improve load distribution by regulating backlash during assembly. A new arrangement for face gear is also described. This new mechanism can perform rotations between axes that are collinear and intersected. Finally the design and simulation of an isostatic planetary gear train is presented. Conditions that can lead to noise and vibration of the planetary gear drive are described

New environmental and spatial approach to Tiwanaku World Heritage site (Bolivia) using remote sensing (UAV and satellite images)

This paper analyses the research carried out in the Tiwanaku World Heritage site in Bolivia, using Unmanned Aerial Vehicles (UAV) and satellite images. The combined use of images with different scales has made it possible to locate many archaeological structures unknown to date (drainage systems, walls, circular crop marks and a possible dock). The Sentinel-2 images, which were processed using principal components analysis and histogram equalization, show the river beds, flood-prone areas and several buried drainage channels surrounding the most important structures. The archaeological evidence obtained with the DTM and natural colour / multispectral images enables us to contrast a new dimension of land and water uses that goes beyond what was known to date. In the same way, these images enable us to understand in detail the environmental characteristics, land use, building distribution and flood defence structures of the Tiwanaku culture throughout its history, within the context of the environmental conditions of the Bolivian altiplano. This investigation allowed collection of new information and posed questions on the relationship of this site with water, as well as a better understanding of the extent and habitat features of this historical population

Cooperative learning in a Engineering Teaching Framework: an introductory experience to Teamworking

Proyecto de Innovación Educativa PIE13-021: Aprendizaje Cooperativo/Colaborativo en el ámbito de la Ingeniería (ACAI)La enseñanza universitaria en el ámbito de la Ingeniería ha estado tradicionalmente orientada al trabajo individual del alumno, lo cual dificulta la adquisición de una de las aptitudes más valoradas en el mercado laboral, como es la competencia de trabajo en grupo. Este trabajo tiene como objetivo fomentar una componente de esta competencia, como es la interacción entre los estudiantes. Para ello se han diseñado y puesto en práctica una serie de actividades docentes en la asignatura “Microcontroladores“, asignatura de 2º curso común a los estudios de Grado en Ingeniería de Sistemas Electrónicos, Sistemas de Telecomunicación, Telemática, Tecnologías de Telecomunicación, y Sonido e Imagen, en la Universidad de Málaga. Asimismo, se ha establecido un conjunto de indicadores que permiten evaluar el grado de consecución de la meta planteada. Los resultados han puesto de manifiesto que la interacción entre los estudiantes se puede fomentar mediante el conjunto de acciones planificadas, aunque las mismas requieren un esfuerzo adicional por parte del profesorado. Finalmente, se han propuesto algunas mejoras en el diseño del procedimiento, para mejorar su eficacia. Este trabajo se enmarca en el proyecto ACAI, cuyo objetivo es implementar un diseño curricular para el desarrollo de la competencia de Trabajo en Grupo. Así, se propone continuar la experiencia aquí presentada fomentando, para los mismos estudiantes, otras componentes de la competencia en asignaturas de 3º y 4º de los grados mencionados.Proyecto de Innovación Educativa PIE13-021, concedido por el Vicerrectorado de Profesorado, Formación, y Coordinación de la Universidad de Málaga

Entrenamiento de las señales corticales a través de un sistema BMI-EEG, evolución e intervención. A propósito de un caso = Training cortical signals by means of a BMI-EEG system, its evolution and intervention. A case report

INTRODUCTION: In the last years, new technologies such as the brain-machine interfaces (BMI) have been incorporated in the rehabilitation process of subjects with stroke. These systems are able to detect motion intention, analyzing the cortical signals using different techniques such as the electroencephalography (EEG). This information could guide different interfaces such as robotic devices, electrical stimulation or virtual reality. CASE REPORT: A 40 years-old man with stroke with two months from the injury participated in this study. We used a BMI based on EEG. The subject's motion intention was analyzed calculating the event-related desynchronization. The upper limb motor function was evaluated with the Fugl-Meyer Assessment and the participant's satisfaction was evaluated using the QUEST 2.0. The intervention using a physical therapist as an interface was carried out without difficulty. CONCLUSIONS: The BMI systems detect cortical changes in a subacute stroke subject. These changes are coherent with the evolution observed using the Fugl-Meyer Assessment

New Evidence on Regucalcin, Body Composition, and Walking Ability Adaptations to Multicomponent Exercise Training in Functionally Limited and Frail Older Adults

Background: Regucalcin, or senescence marker protein-30 (SMP30), is a Ca2+-binding protein with multiple functions reported in the literature. Physical exercise has been shown to improve aging markers; nevertheless, SMP30 in humans has not been extensively researched. Older adults experience a decline in functional capacity and body composition. The purpose of this study was to examine the effects of a multicomponent training (MCT) program on SMP30 and its regulation of walking ability and body composition in functionally limited, frail, and pre-frail older adults. Methods: A total of 34 older adults (aged 80.3 +/- 6.1 years) were divided into an intervention group (IG = 20) and control group (CG = 14). The IG performed a supervised MCT (strength, endurance, balance, coordination, and flexibility) program for 6 months, 3 days per week, whereas the CG continued their normal lives without any specific physical training. SMP30 was analyzed in plasma after 3 and 6 months of MCT, while some physical fitness variables (Timed Up and Go (TUG) and 6-min walk test (6MWT)) and body composition (fat mass and lean mass) were measured at baseline, as well as after 3 months and 6 months of MCT. Results: No significant changes were observed in SPM30 between the IG (877.5 a.u. to 940.5 a.u., respectively) and CG (790.4 a.u. to 763.8 a.u., respectively). Moreover, no SMP30 differences were found between groups after 3 and 6 months of MCT. The IG improved significantly in the 6MWT after 3 months (472.2 +/- 84.2 m) compared to baseline (411.2 +/- 75.2 m). The IG also significantly enhanced their TUG performance after 3 months (7.6 +/- 1.6 s) and 6 months (7.3 +/- 1.8 s) of training compared to baseline (9.3 +/- 3.2 s) (all, p < 0.001). There were no significant differences in body composition between the IG and CG through the 6 months of MCT. Conclusions: The present study suggests that MCT did not change SMP30 levels from 3 to 6 months, where there were changes in neither walking ability nor body composition; however, MCT was effective in improving 6MWT and TUG performance from baseline to 3 months