E-Racer

The E-Racer was made for a young boy with cerebral palsy. The client cannot use his legs and control in his left arm is very limited. The client's family expressed a desire for an electric go-kart, and also for the go-kart to resemble a "normal" go-kart. To that end, the E-Racer has been outfitted with both steering wheel and joystick modes so the client can choose which control system he would like to use depending on what he is comfortable with. The E-Racer is a stock go-kart which was modified in several key ways. The electronics were drastically modified to accommodate the two controls systems. In addition, both the steering and braking systems were modified so they could be controlled electrically rather than mechanically. Finally, several modifications were made to the go-kart to improve the rider's comfort and safety.

The University Compost Facility after Three Years

The University Compost Facility, 52274 260th St., Ames, Iowa has completed three full years of operation. The facility is managed by the ISU Research Farms and has a separate revolving account that receives fees and sales, and pays expenses. The facility is designed to be self-supporting, i.e. not receive allocations for its operations. The facility consists of seven, 80 × 140 ft hoop barns and a new 55 × 120 ft hoop barn, all with paved floors. The facility also has a Mettler-Toledo electronic scale with a 10 ft × 70 ft platform to weigh all materials. Key machinery is 1) compost turner, a used pull-type Aeromaster PT-170, 14 ft wide made by Midwest Biosystems, Tampico, IL; 2) a converted dump truck trailer used to construct windrows and haul material; 3) telehandler, Caterpillar TH407 with cab and 2.75 cubic yard bucket; and 4) tractor, John Deere 7520 (125 hp) with IVT (Infinite Variable Transmission) and front-wheel assist used to pull the turner and dump trailer.

Determinación de la microdureza de la dentina coronaria previamente acondicionada

La dureza es una de las propiedades utilizadas para comparar tanto los materiales restauradores como los tejidos biológicos. El objetivo de este trabajo es determinar la microdureza de la dentina coronaria en dientes sin acondicionar y luego acondicionados con EDTA al 17%. Para este estudio se seleccionaron 30 muestras de dentina de dientes recientemente extraídos. Los elementos fueron seccionados longitudinalmente con discos de diamante de doble corte (Horico), con abundante refrigeración acuosa, a nivel coronario, y serán conservados en saliva artificial (laboratorio NAF) a 37°C. La medición de la microdureza dentinaria se realizó con un microdurómetro Vickers, con una carga de 50g durante 30 s. Los datos fueron recolectados en una planilla ad hoc y procesados estadísticamente mediante el Test de Student.

De la rueda de libros a la escritura enciclopédica

En 1588, el inventor italiano Agostino Ramelli publicó el libro Le diverse et artificiose machine. Entre las muchas máquinas de ingeniería hidráulica y militar, un total de 195 aparatos, destaca un artilugio construido para facilitar la lectura de varios libros a la vez. Esta llamada "rueda de libros" se suele citar en publicaciones recientes como precursora del hipertexto ya que esta máquina para leer permite saltar de un texto a otro de la misma manera que nos movemos entre páginas WEB y módulos textuales. Se trata de una invención que los investigadores describen como reacción al desafío que plantea la enorme cantidad de saber libresco que circula gracias a otra invención que era la imprenta con letras móviles. Aunque muy posiblemente nunca hubiera llegado a construirse, se trata de un artefacto que funciona potencialmente como una máquina de producir textos o, dicho de otra manera, como dispositivo de impulsar un determinado tipo de escritura. Me propongo leer florilegios, obras enciclopédicas y polianteas como Lugares comunes de Juan de Aranda o la escritura enciclopédica en obras como el Guzmán de Alfarache, La pícara Justina o el Libro de todas las cosas como productos virtuales de la rueda de libros.

Diferenciación social campesina en concejos de abadengo (siglos XIII-XVI)

Partiendo de la documentación correspondiente al Monasterio de Santo Toribio de Liébana se indagó sobre la existencia de políticas señoriales diferenciales que favorecieron la polarización social de las comunidades dependientes. El proceso de subdivisión de las antiguas unidades domésticas, que se constituía en un mecanismo tradicional de incremento de las exacciones, propiciaba la paulatina pauperización de los sectores tributarios medios, que debían buscar en el trabajo asalariado el complemento necesario para su subsistencia. Paralelamente, la persistencia de vínculos diferenciales con algunos miembros de la comunidad (que comprometían su accionar en la consolidación de los derechos patrimoniales del monasterio y se constituían en el engranaje más pequeño del aparato de dominación feudal) fomentaban la reproducción social de los pecheros ricos que inician a lo largo del siglo XV, con la anuencia del señor, un proceso de acumulación de pequeñas tenencias a censo. El análisis propuesto se aleja de las posturas historiográficas que centran el estudio en el movimiento de las "variables económicas objetivas" y reinserta la problemática de la diferenciación social en el marco del señorío.

De la rueda de libros a la escritura enciclopédica

En 1588, el inventor italiano Agostino Ramelli publicó el libro Le diverse et artificiose machine. Entre las muchas máquinas de ingeniería hidráulica y militar, un total de 195 aparatos, destaca un artilugio construido para facilitar la lectura de varios libros a la vez. Esta llamada "rueda de libros" se suele citar en publicaciones recientes como precursora del hipertexto ya que esta máquina para leer permite saltar de un texto a otro de la misma manera que nos movemos entre páginas WEB y módulos textuales. Se trata de una invención que los investigadores describen como reacción al desafío que plantea la enorme cantidad de saber libresco que circula gracias a otra invención que era la imprenta con letras móviles. Aunque muy posiblemente nunca hubiera llegado a construirse, se trata de un artefacto que funciona potencialmente como una máquina de producir textos o, dicho de otra manera, como dispositivo de impulsar un determinado tipo de escritura. Me propongo leer florilegios, obras enciclopédicas y polianteas como Lugares comunes de Juan de Aranda o la escritura enciclopédica en obras como el Guzmán de Alfarache, La pícara Justina o el Libro de todas las cosas como productos virtuales de la rueda de libros.

Diferenciación social campesina en concejos de abadengo (siglos XIII-XVI)

Partiendo de la documentación correspondiente al Monasterio de Santo Toribio de Liébana se indagó sobre la existencia de políticas señoriales diferenciales que favorecieron la polarización social de las comunidades dependientes. El proceso de subdivisión de las antiguas unidades domésticas, que se constituía en un mecanismo tradicional de incremento de las exacciones, propiciaba la paulatina pauperización de los sectores tributarios medios, que debían buscar en el trabajo asalariado el complemento necesario para su subsistencia. Paralelamente, la persistencia de vínculos diferenciales con algunos miembros de la comunidad (que comprometían su accionar en la consolidación de los derechos patrimoniales del monasterio y se constituían en el engranaje más pequeño del aparato de dominación feudal) fomentaban la reproducción social de los pecheros ricos que inician a lo largo del siglo XV, con la anuencia del señor, un proceso de acumulación de pequeñas tenencias a censo. El análisis propuesto se aleja de las posturas historiográficas que centran el estudio en el movimiento de las "variables económicas objetivas" y reinserta la problemática de la diferenciación social en el marco del señorío.

De la rueda de libros a la escritura enciclopédica

En 1588, el inventor italiano Agostino Ramelli publicó el libro Le diverse et artificiose machine. Entre las muchas máquinas de ingeniería hidráulica y militar, un total de 195 aparatos, destaca un artilugio construido para facilitar la lectura de varios libros a la vez. Esta llamada "rueda de libros" se suele citar en publicaciones recientes como precursora del hipertexto ya que esta máquina para leer permite saltar de un texto a otro de la misma manera que nos movemos entre páginas WEB y módulos textuales. Se trata de una invención que los investigadores describen como reacción al desafío que plantea la enorme cantidad de saber libresco que circula gracias a otra invención que era la imprenta con letras móviles. Aunque muy posiblemente nunca hubiera llegado a construirse, se trata de un artefacto que funciona potencialmente como una máquina de producir textos o, dicho de otra manera, como dispositivo de impulsar un determinado tipo de escritura. Me propongo leer florilegios, obras enciclopédicas y polianteas como Lugares comunes de Juan de Aranda o la escritura enciclopédica en obras como el Guzmán de Alfarache, La pícara Justina o el Libro de todas las cosas como productos virtuales de la rueda de libros.

Diferenciación social campesina en concejos de abadengo (siglos XIII-XVI)

Partiendo de la documentación correspondiente al Monasterio de Santo Toribio de Liébana se indagó sobre la existencia de políticas señoriales diferenciales que favorecieron la polarización social de las comunidades dependientes. El proceso de subdivisión de las antiguas unidades domésticas, que se constituía en un mecanismo tradicional de incremento de las exacciones, propiciaba la paulatina pauperización de los sectores tributarios medios, que debían buscar en el trabajo asalariado el complemento necesario para su subsistencia. Paralelamente, la persistencia de vínculos diferenciales con algunos miembros de la comunidad (que comprometían su accionar en la consolidación de los derechos patrimoniales del monasterio y se constituían en el engranaje más pequeño del aparato de dominación feudal) fomentaban la reproducción social de los pecheros ricos que inician a lo largo del siglo XV, con la anuencia del señor, un proceso de acumulación de pequeñas tenencias a censo. El análisis propuesto se aleja de las posturas historiográficas que centran el estudio en el movimiento de las "variables económicas objetivas" y reinserta la problemática de la diferenciación social en el marco del señorío.

Zooplankton carbon budget from Trondheim mesocosm experiment

We measured respiration, egg production and fecal pellet production of five common copepod species, when fed on suspended or aggregated food from two mesocosm, + NP and + NPSi. We hypothetised that calanoid copepods (Temora longicornis, Acartia spp., Centropages spp.) would feed mainly on suspended food, and have low respiration and egestion rates when food was only available as aggregates, while harpacticoids and Oncaea spp. would mainly feed on aggregated food and have low metabolic rates when only suspended food was available. Copepods were collected from the lagoon, and adapted to experimental conditions for 24 h. Food suspension was collected from the mesocosms, and either offered to copepods directly (suspended food) or after rotating in a plankton wheel until most phytoplankton was aggregated together (aggregated food). After 24-h incubation we counted the produced eggs and pellets, and measured copepod respiration using microelectrodes.

Essays on Inequality and Integration

Inequality and integration have been sociology’s two key paradigms since the classics, associated with the names of Marx and Durkheim and Europe’s current economic crisis has forcefully reinvigorated their joint relevance. Above all, the debt crisis has fueled the wheel of social inequality: cash-starved states are further forced to cut back on public expenditures, to minimize the margin for redistribution and to raise new challenges for the integration policies addressing the emerging disparities. At the same time, global environmental and demographic problems, intertwined with escalating migration pressure, tear at the texture of European and all Western societies, in particular, the unequal impact of climate change and the unequal distribution of population growth make migration and integration paramount public policy issues and a soaring source of social conflict. In principle, the inequalities engendered by these cascading processes are also an opportunity. They increase the diversity of society and can bring about innovation and growth. Our desire and ability for social integration depends, above all, on the ultimate balance between these advantages and disadvantages. The chapters in the volume concentrate on the opportunities as well as the risks associated with these social changes from various angles. They are a handpicked set of outstanding contributions from the Congress of the Swiss Sociological Association that took place at the University of Bern, June 26–28, 2013.

Simulation of Freight Trains Equipped with Partially Filled Tank Containers and Related Resonance Phenomenon

To study the fluid motion-vehicle dynamics interaction, a model of four, liquid filled two-axle container freight wagons was set up. The railway vehicle has been modelled as a multi-body system (MBS). To include fluid sloshing, an equivalent mechanical model has been developed and incorporated. The influence of several factors has been studied in computer simulations, such as track defects, curve negotiation, train velocity, wheel wear, liquid and solid wagonload, and container baffles. SIMPACK has been used for MBS analysis, and ANSYS for liquid sloshing modelling and equivalent mechanical systems validation. Acceleration and braking manoeuvres of the freight train set the liquid cargo into motion. This longitudinal sloshing motion of the fluid cargo inside the tanks initiated a swinging motion of some components of the coupling gear. The coupling gear consists of UIC standard traction hooks and coupling screws that are located between buffers. One of the coupling screws is placed in the traction hook of the opposite wagon thus joining the two wagons, whereas the unused coupling screw rests on a hanger. Simulation results showed that, for certain combinations of type of liquid, filling level and container dimensions, the liquid cargo could provoke an undesirable, although not hazardous, release of the unused coupling screw from its hanger. The coupling screw's release was especially obtained when a period of acceleration was followed by an abrupt braking manoeuvre at 1 m/s2. It was shown that a resonance effect between the liquid's oscillation and the coupling screw's rotary motion could be the reason for the coupling screw's undesired release. Possible solutions to avoid the phenomenon are given.Acceleration and braking manoeuvres of the freight train set the liquid cargo into motion. This longitudinal sloshing motion of the fluid cargo inside the tanks initiated a swinging motion of some components of the coupling gear. The coupling gear consists of UIC standard traction hooks and coupling screws that are located between buffers. One of the coupling screws is placed in the traction hook of the opposite wagon thus joining the two wagons, whereas the unused coupling screw rests on a hanger. This paper reports on a study of the fluid motion-train vehicle dynamics interaction. In the study, a model of four, liquid-filled two-axle container freight wagons was developed. The railway vehicle has been modeled as a multi-body system (MBS). To include fluid sloshing, an equivalent mechanical model has been developed and incorporated. The influence of several factors has been studied in computer simulations, such as track defects, curve negotiation, train velocity, wheel wear, liquid and solid wagonload, and container baffles. A simulation program was used for MBS analysis, and a finite element analysis program was used for liquid sloshing modeling and equivalent mechanical systems validation. Acceleration and braking maneuvers of the freight train set the liquid cargo into motion. This longitudinal sloshing motion of the fluid cargo inside the tanks initiated a swinging motion of some components of the coupling gear. Simulation results showed that, for certain combinations of type of liquid, filling level and container dimensions, the liquid cargo could provoke an undesirable, although not hazardous, release of an unused coupling screw from its hanger. It was shown that a resonance effect between the liquid's oscillation and the coupling screw's rotary motion could be the reason for the coupling screw's undesired release. Solutions are suggested to avoid the resonance problem, and directions for future research are given.

Effectiveness of resilient wheels in reducing noise and vibrations

This study focuses on the effectiveness of resilient wheels in reducing railway noise and vibrations, and compares the effectiveness of three types of wheels. The finite elements method has been used to characterise the vibratory behaviour of these wheels. The model has been excited with a realistic spectrum of vertical track irregularities, and a spectral analysis has been carried out. Results have been post-processed in order to estimate the sound power emitted. These calculations have been used to assess the effectiveness of the resilient wheel designs in reducing noise emitted to the environment and in propagating structural vibrations.

Comparison of vibration and rolling noise emission of resilient and solid monobloc railway wheels in underground lines

Flat or worn wheels rolling on rough or corrugated tracks can provoke airborne noise and ground-borne vibration, which can be a serious concern for nearby neighbours of urban rail transit lines. Among the various treatments used to reduce vibration and noise, resilient wheels play an important role. In conventional resilient wheels, a slightly prestressed V­shaped rubber ring is mounted between the steel wheel centre and tyre. The elastic layer enhances rolling noise and vibration suppression, as well as impact reduction on the track. In this paper the effectiveness of resilient wheels in underground lines, in comparison to monobloc ones, is assessed. The analysed resilient wheel is able to carry greater loads than standard resilient wheels used for light vehicles. It also presents a greater radial resiliency and a higher axial stiffness than conventional V­wheels. The finite element method was used in this study. A quarter car model was defined, in which the wheelset was modelled as an elastic body. Several simulations were performed in order to assess the vibrational behaviour of elastic wheels, including modal, harmonic and random vibration analysis, the latter allowing the introduction of realistic vertical track irregularities, as well as the influence of the running speed. Due to numerical problems some simplifications were needed. Parametric variations were also performed, in which the sensitivity of the whole system to variations of rubber prestress and Poisson’s ratio of the elastic material was assessed.Results are presented in the frequency domain, showing a better performance of the resilient wheels for frequencies over 200 Hz. This result reveals the ability of the analyzed design to mitigate rolling noise, but not structural vibrations, which are primarily found in the lower frequency range.

Dynamic effect of high speed railway traffic loads on the ballast track settlement

The traditional ballast track structures are still being used in high speed railways lines with success, however technical problems or performance features have led to non-ballast track solution in some cases. A considerable maintenance work is needed for ballasted tracks due to the track deterioration. Therefore it is very important to understand the mechanism of track deterioration and to predict the track settlement or track irregularity growth rate in order to reduce track maintenance costs and enable new track structures to be designed. The objective of this work is to develop the most adequate and efficient models for calculation of dynamic traffic load effects on railways track infrastructure, and then evaluate the dynamic effect on the ballast track settlement, using a ballast track settlement prediction model, which consists of the vehicle/track dynamic model previously selected and a track settlement law. The calculations are based on dynamic finite element models with direct time integration, contact between wheel and rail and interaction with railway cars. A initial irregularity profile is used in the prediction model. The track settlement law is considered to be a function of number of loading cycles and the magnitude of the loading, which represents the long-term behavior of ballast settlement. The results obtained include the track irregularity growth and the contact force in the final interaction of numerical simulation