Analytical studies of new airfoils for wind turbines

Computer studies were conducted to analyze the potential gains associated with utilizing new airfoils for large wind turbine rotor blades. Attempts to include 3-dimensional stalling effects were inconclusive. It is recommended that blade pressure measurements be made to clarify the nature of blade stalling. It is also recommended that new laminar flow airfoils be used as rotor blade sections

Nutritional support for head-injured patients

Copyright John Wiley & Sons. This review is published as a Cochrane Review in the Cochrane Database of Systematic Reviews 2004, Issue 3. Cochrane Reviews are regularly updated as new evidence emerges and in response to comments and criticisms, and the Cochrane Database of Systematic Reviews should be consulted for the most recent version of the Review.’ Perel, P. , Yanagawa, T. , Bunn, F. , Roberts, I. , Wentz, R. and Pierro, A. Nutritional support for head-injured patients. Cochrane Database of Systematic Reviews 2004, Issue 3. Art. No.: CD001530. DOI: 10.1002/14651858.CD001530.pub2Background: Head injury increases the body's metabolic responses, and therefore nutritional demands. Provision of an adequate supply of nutrients is associated with improved outcome. The best route for administering nutrition (parenterally (TPN) or enterally (EN)), and the best timing of administration (for example, early versus late) of nutrients needs to be established. Objectives: To quantify the effect on mortality and morbidity of alternative strategies of providing nutritional support following head injury. Search strategy: Trials were identified by computerised searches of the Cochrane Injuries Group specialised register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, National Research Register, Web of Science and other electronic trials registers. Reference lists of trials and review articles were checked. The searches were last updated in July 2006. Selection criteria: Randomised controlled trials of timing or route of nutritional support following acute traumatic brain injury. Data collection and analysis: Two authors independently abstracted data and assessed trial quality. Information was collected on death, disability, and incidence of infection. If trial quality was unclear, or if there were missing outcome data, trialists were contacted in an attempt to get further information. Main results: A total of 11 trials were included. Seven trials addressed the timing of support (early versus delayed), data on mortality were obtained for all seven trials (284 participants). The relative risk (RR) for death with early nutritional support was 0.67 (95% CI 0.41 to 1.07). Data on disability were available for three trials. The RR for death or disability at the end of follow-up was 0.75 (95% CI 0.50 to 1.11). Seven trials compared parenteral versus enteral nutrition. Because early support often involves parenteral nutrition, three of the trials are also included in the previous analyses. Five trials (207 participants) reported mortality. The RR for mortality at the end of follow-up period was 0.66 (0.41 to 1.07). Two trials provided data on death and disability. The RR was 0.69 (95% Cl 0.40 to 1.19). One trial compared gastric versus jejunal enteral nutrition, there were no deaths and the RR was not estimable. Authors' conclusions: This review suggests that early feeding may be associated with a trend towards better outcomes in terms of survival and disability. Further trials are required. These trials should report not only nutritional outcomes but also the effect on death and disability.Peer reviewe

Feasibility study of aileron and spoiler control systems for large horizontal axis wind turbines

The feasibility of using aileron or spoiler controls as alternates to pitch control for large horizontal axis wind turbines was studied. The NASA Mod-0 100 kw machine was used as the basis for the study. Specific performance studies were conducted for 20% chord ailerons over the outboard 30% span, and for 10% chord spoilers over the same portion of the span. Both control systems utilized control deflections up to 60 deg. Results of the study show that either ailerons or spoilers can provide the control necessary to limit turbine power in high wind conditions. The aileron system, as designed, provides overspeed protection at hurricane wind speeds, low wind speed starting torque of 778 N-m (574 ft. lb) at 3.6 m/sec, and a 1.3 to 1.5% increase in annual energy compared to a fixed pitch rotor. The aileron control system preliminary design study includes aileron loads analysis and the design of a failsafe flyweight actuator for overspeed protection in the event of a hydraulic system failure

RF model of the distribution system as a communication channel, phase 2. Volume 4: Sofware source program and illustrations ASCII database listings

Listings of source programs and some illustrative examples of various ASCII data base files are presented. The listings are grouped into the following categories: main programs, subroutine programs, illustrative ASCII data base files. Within each category files are listed alphabetically

RF model of the distribution system as a communication channel, phase 2. Volume 3: Appendices

Program documentation concerning the design, implementation, and verification of a computerized model for predicting the steady-state sinusoidal response of radial configured distribution feeders is presented in these appendices

A modular neural interface for massively parallel recording and control : subsystem design considerations for research and clinical applications

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 78-79).The closed-loop Brain-Machine Interface (BMI) has long been a dream for clinicians and neuroscience researchers alike - that is, the ability to extract meaningful information from the brain, perform computation on this information, and selectively perturb neural dynamics in the brain for therapeutic benefit to the patient. Such systems have immediate application to treatment of paralysis, epilepsy and the amputated, and the potential for treatment of higher order cognitive dysfunction. Despite the promise of the BMI concept, the technology for bidirectional communication with the brain at sufficiently large scale to be truly therapeutically useful is lacking. Current state-of-the-art neuromodulation systems deliver open loop, 16-channel patterned electrical stimulation incapable of precisely targeting small numbers of neurons. Large-scale neural recording systems are limited to 16-128 electrodes, at the cost of several thousand dollars per channel. The ability to record from the awake behaving animal - let alone precisely modulate neural network dynamics in closed-loop fashion- presents a substantial challenge today.In this thesis, I present decoupled design solutions for three critical subcomponents of the closed-loop BMI - (i) a highly miniature, wirelessly powered and wirelessly controlled implantable optogenetic neuromodulation system capable of selective neural network control with single neural subtype- and millisecond-timescale precision, (ii) a prototype, highly parallel and scalable bio-potential recording system for simultaneous monitoring of many thousands of electrodes, and (iii) a space- and energy-efficient battery charger for biomedical applications. In aggregate, these systems overcome many of the fundamental architectural problems seen in the research and clinical environment today, potentially enabling a new class of neuromodulation system capable of treatment of higher-order cognitive dysfunction. In the research setting, these systems may be scaled to enable whole-brain recording, potentially yielding insights into large-scale neural network dynamics underlying disease and cognition.by Christian T. Wentz.M.Eng

Ocean Surface Emissivity at L-band (1.4 GHz): The Dependence on Salinity and Roughness

A characterization of the emissivity of sea water at L-band is important for the remote sensing of sea surface salinity. Measurements of salinity are currently being made in the radio astronomy band at 1.413 GHz by ESA's Soil Moisture and Ocean Salinity (SMOS) mission and NASA's Aquarius instrument aboard the Aquarius/SAC-D observatory. The goal of both missions is accuracy on the order of 0.1 psu. This requires accurate knowledge of the dielectric constant of sea water as a function of salinity and temperature and also the effect of waves (roughness). The former determines the emissivity of an ideal (i.e. flat) surface and the later is the major source of error from predictions based on a flat surface. These two aspects of the problem of characterizing the emissivity are being addressed in the context of the Aquarius mission. First, laboratory measurements are being made of the dielectric constant of sea water. This is being done at the George Washington University using a resonant cavity. In this technique, sea water of known salinity and temperature is fed into the cavity along its axis through a narrow tube. The sea water changes the resonant frequency and Q of the cavity which, if the sample is small enough, can be related to the dielectric constant of the sample. An extensive set of measurements have been conducted at 1.413 GHz to develop a model for the real and imaginary part of the dielectric constant as a function of salinity and temperature. The results are compared to the predictions of models based on parameterization of the Debye resonance of the water molecule. The models and measurements are close; however, the differences are significant for remote sensing of salinity. This is especially true at low temperatures where the sensitivity to salinity is lowest

"Transformai As Velhas Formas do Viver: Sobre As Potências da Fotografia Junto As Paisagens Urbanas"

A partir do encontro de uma frase pichada no parapeito de uma ponte, a presente pesquisa indaga sobre as paisagens urbanas e alguns dos modos de subjetivação em curso na cidade de Vitória. Em conjunto com o Laboratório de imagens da subjetividade (LIS), o pesquisador questiona-se sobre as possibilidades de construção de um dispositivo de interferência urbana por meio da fotografia. Utilizando-se de uma metodologia do caminhar pelas ruas e junto a técnicas da fotografia, cria-se nesse trabalho uma trajetória imagética de um olhar singular daquele que perambula pelas ruas da cidade, e que em um movimento semelhante ao piscar dos olhos retém instantes desses lugares e de suas pessoas. Instantes nunca grandiosos, nunca relevantes para os grandes veículos, mas que ainda assim, como os homens infames em Michael Foucault, são repletos de narrativas sobre um cotidiano da vida que passa em paralelo a um discurso maior. A fotografia, portanto, para além de uma prática que se dedica ao instante decisivo, como proposto por Henri Cartier-Bresson, é também o exercício da construção de instantes infames, que resistem e procuram por vozes e ouvidos, dizem de si e convidam a uma fala que não a da mera transmissão de informação. Essa fotografia enquanto ferramenta de intervenção carrega consigo, as potências do puctum, as potências clínicas de uma ferroada, de uma flechada, que feito os buracos em um muro, são capazes de nos ferir e abrir fendas na superfície de nossas peles enrijecidas. Essa fotografia aliada à clínica, abre espaços para outros ares, outros olhares e outros possíveis modos junto à cidade. E será menos por vias da luz e mais pelos instantes de cegueira, enquanto o obturador da máquina fotográfica abre-se à luz e os olhos se fecham, enquanto entregamo-nos às trevas, que a cidade conta suas histórias não oficiais, não lineares: suas narrativas infames que potentes em suas diferenças, insistem em não se renderem ao desejo de conformismo do ta tudo dominado e aos aparelhos de captura e de manutenção de um poder que se gostaria hegemônico sobre a vida. Palavras Chave: Produção de subjetividade, Cidade, Fotografia, Clínica