Las superficies pictóricas de Turner: el papel de los molinos papeleros

El presente texto incluye una breve historia de la máquina de papel y su inventor Nicholas-Louis Robert, y una exploración del trabajo de experimentación con distintos papeles del pintor inglés William Turner

A novel correlation for rapid lactose determination in milk by a cryoscopic technique

Producción CientíficaResidual lactose in special milk was systematically determined for people with lactose intolerance by means of a rapid on-line measurement of the cryoscopic point. A proposed cryoscopic procedure was compared to 2 conventional yet highly laborious methods: the enzymatic procedure with spectrophotometric control and the polarimetric method. Several experiments with different mixtures of both semi-skimmed and low-lactose milk were performed. A lineal relationship was found between lactose concentration and freezing point, the analytical equation for which shows a close relationship regarding the 3 methods used. The advantages of the cryoscopic procedure include speed in obtaining results and operational simplicity at a low cost, better monitoring of enzymatic hydrolysis kinetics, and greater control over the production process for delactosed milk. The equation obtained also enables prediction of the lactose percentage in commercial milk by a simple measurement of freezing point

Rapid Prototyping for Evaluating Vehicular Communications

[Abstract] This Thesis details the different elements of a rapid prototyping system able to implement and evaluate vehicular communications fast, according to the continuously evolving requirements of the industry. The system is basically composed of a testbed and a channel emulator, which allow evaluating communication transceivers in realistic vehicular scenarios. Two different testbeds are introduced: a generic 2x2 system and a vehicular platform. The former is used to compare and study space-time block coding (STBC) transmissions at 2.4 GHz over different indoor channels. The latter makes use of software transceivers whose performance is evaluated when they work under artificial high-speed Rayleigh-fading scenarios. To show the capabilities of both platforms, three software transceivers have been developed following the specifications for the physical layers of the standards IEEE 802.11p, IEEE 802.11a and IEEE 802.16e (Mobile WiMAX). The present work details the different elements that make up each transceiver and indicates how to connect them to the rest of the system to perform evaluation measurements. Finally, single-antenna and multi-antenna performances are measured thanks to the design and implementation of three FPGA-based channel emulators that are able to recreate up to seven different vehicular scenarios that include urban canyons, suburban areas and highways[Resumo] A presente Tese detalla os elementos necesarios para constituir un sistema basado en prototipado rápido capaz de levar a cabo e avaliar comunicacións vehiculares. O hardware do sistema está composto básicamente por unha plataforma de probas (testbed) e un emulador de canal, os cales permiten avaliar o rendemento de transceptores inartiamicos recreando diferentes escenarios vehiculares. Inicialmente, este traballo céntrase na descripción do hardware do sistema, detallando a construcción e proba dunha plataforma multi-antena e un testebed vehicular. Estos sistemas permitiron, respectivamente, estudar o comportamento de códigos STBC (space-time block codes) en interiores e medir o rendemento de tranceptores software ao traballar a distintas velocidades vehiculares en canais con desvaecemento Rayleigh. Tres transceptores software foron creados seguindo as especificacións das capas físicas dos estándares IEEE 802.11p, IEEE 802.11a e IEEE 802.16e (Mobile WiMAX). Este traballo detalla os diferentes componentes de cada transceptor, indicando cómo conectalos ao resto do sistema para realizar a avaliacition do seu rendemento. Dita avaliación realizouse coa axuda de tres emuladores de canal basados en tecnoloxía FPGA (Field Programmable Gate Array), os cales son capaces de recrear ata sete escenarios vehiculares distintos, incluindo cañóns urbanos, zonas suburbanas e autopistas.[Resumen] La presente Tesis detalla los elementos necesarios para constituir un sistema basado en prototipado rtiapido capaz de llevar a cabo y evaluar comunicaciones vehiculares. El hardware del sistema está compuesto por una plataforma de pruebas (testbed) y un emulador de canal, los cuales permiten evaluar el rendimiento de transceptores inaltiambricos recreando diferentes escenarios vehiculares. Inicialmente, este trabajo se centra en la descripcition del hardware del sistema, detallando la construccition y prueba de una plataforma multi-antena y un testebed vehicular. Estos sistemas han permitido, respectivamente, estudiar el comportamiento de ctiodigos STBC (space-time block codes) en interiores y medir el rendimiento en canal con desvanecimiento Rayleigh de tranceptores software a distintas velocidades vehiculares. Tres transceptores software han sido creados siguiendo las especificaciones de las capas físicas de los estandares IEEE 802.11p, IEEE 802.11a e IEEE 802.16e (Mobile WiMAX). Este trabajo detalla los diferentes componentes de cada transceptor, indicando ctiomo conectarlos al resto del sistema para realizar la evaluacition de su rendimiento. Dicha evaluacition se realiztio con la ayuda de tres emuladores de canal basados en FPGAs (Field Programmable Gate Array), los cuales son capaces de recrear comunicaciones multi-antena en hasta siete escenarios vehiculares distintos, incluyendo cañones urbanos, zonas suburbanas y autopistas

Victimization, Urbanicity, and the Relevance of Context: School Routines, Race and Ethnicity, and Adolescent Violence

The United States is undergoing a historical racial and ethnic demographic shift. There is limited criminological research exploring if and how these changes influence variation in the relationship between routine activity theory and adolescent violence. Although the link between routine activities and victimization has been tested and well established, criminologists have questioned if routine activities can explain adolescent violence across different social contexts. Prior research demonstrates that there are potential nuances in the theoretical connections between routine activities and victimization, particularly when considering race and ethnicity. This study builds on previous research by questioning if the elements of routine activities predict victimization across predominately urban, rural, and suburban schools. The implications of the relevance of school context in the relationships between routine activities and adolescent victimization will also be discussed more generally

Treatment Of A Patient With Thoracolumbar Scoliosis Utilizing A Regional Interdependence Approach Including Components Of The Schroth Method: A Case Report

Background and Purpose: Spinal deformity is a challenging spinal disorder in adults. A scoliotic curve of \u3e10 degrees exists in up to 12% of the population and while surgery is the definitive measure, there is limited evidence to guide non-surgical treatment. This case investigated traditional physical therapy (PT) treatment utilizing a Regional Interdependence Approach (RIA) and components of the Schroth method for a patient with chronic low back pain (CLBP). Case Description: A 66 year old male presented with CLBP, worst upon rising in the AM with (6/10 NPRS). Imaging demonstrated thoracolumbar dextroscoliosis, bilateral foraminal narrowing and associated spondylolisthesis of the fifth lumbar vertebrae. A RIA exam revealed mobility deficits of thoracolumbar spine, instability of L5-S1, and a 1.38” leg length discrepancy. A comprehensive treatment approach was used including lumbar stabilization exercises and postural therapy, including components of the Schroth method. Outcomes: Following 12 weeks, pain improved from 6/10 to 4/105, with the patient reporting no pain when arising from bed. 30-second sit to stand improved from five to eight. Following implementation of a shoe lift visible changes were noted in pelvic symmetry. However, the degree of scoliosis appeared unchanged and no subjective improvements were noted on the Roland-Morris Low Back Pain Questionnaire (RMLBPQ)

Contribución al conocimiento de la distribución y aspectos biológicos de algunas especies de mosquitos en Haití

El terremoto de 2010 en Haití agravó las condiciones higiénicas sanitarias y ambientales, al aumentar la disponibilidad de sitios de cría de mosquitos vectores. Ante esta situación, como parte de la ayuda que Cuba brinda a este país, se incluyó la vigilancia y lucha antivectorial como un componente importante en el control de las enfermedades vectoriales. En el presente estudio se realizó un muestreo larval de mosquitos en 35 comunas, distribuidas en los 10 departamentos de Haití en el período entre Junio 2010 - Junio, 2011, utilizándose la metodología recomendada por la OMS. Se identificaron 21 especies. Las más abundantes y de mayor distri- bución fueron Aedes aegypti, Culex quinquefasciatus, Anopheles albimanus y Culex nigripalpus, constituyendo el 90,1% del total. Durante este trabajo, se detectó la presencia de Aedes albopictus, que constituyó el primer reporte de esta especie para Haití. Estos resultados actualizados constituyen un aporte al conocimiento de la fauna de mosquito en Haití