2,112 research outputs found
Species and temperature measurement in H2/O2 rocket flow fields by means of Raman scattering diagnostics
Validation of Computational Fluid Dynamics (CFD) codes developed for prediction and evaluation of rocket performance is hampered by a lack of experimental data. Non-intrusive laser based diagnostics are needed to provide spatially and temporally resolved gas dynamic and fluid dynamic measurements. This paper reports the first non-intrusive temperature and species measurements in the plume of a 110 N gaseous hydrogen/oxygen thruster at and below ambient pressures, obtained with spontaneous Raman spectroscopy. Measurements at 10 mm downstream of the exit plane are compared with predictions from a numerical solution of the axisymmetric Navier-Stokes and species transport equations with chemical kinetics, which fully model the combustor-nozzle-plume flowfield. The experimentally determined oxygen number density at the centerline at 10 mm downstream of the exit plane is four times that predicted by the model. The experimental number density data fall between those numerically predicted for the exit and 10 mm downstream planes in both magnitude and radial gradient. The predicted temperature levels are within 10 to 15 percent of measured values. Some of the discrepancies between experimental data and predictions result from not modeling the three dimensional core flow injection mixing process, facility back pressure effects, and possible diffuser-thruster interactions
Fuzzy control system for a remote focusing microscope
Space Station Crew Health Care System procedures require the use of an on-board microscope whose slide images will be transmitted for analysis by ground-based microbiologists. Focusing of microscope slides is low on the list of crew priorities, so NASA is investigating the option of telerobotic focusing controlled by the microbiologist on the ground, using continuous video feedback. However, even at Space Station distances, the transmission time lag may disrupt the focusing process, severely limiting the number of slides that can be analyzed within a given bandwidth allocation. Substantial time could be saved if on-board automation could pre-focus each slide before transmission. The authors demonstrate the feasibility of on-board automatic focusing using a fuzzy logic ruled-based system to bring the slide image into focus. The original prototype system was produced in under two months and at low cost. Slide images are captured by a video camera, then digitized by gray-scale value. A software function calculates an index of 'sharpness' based on gray-scale contrasts. The fuzzy logic rule-based system uses feedback to set the microscope's focusing control in an attempt to maximize sharpness. The systems as currently implemented performs satisfactorily in focusing a variety of slide types at magnification levels ranging from 10 to 1000x. Although feasibility has been demonstrated, the system's performance and usability could be improved substantially in four ways: by upgrading the quality and resolution of the video imaging system (including the use of full color); by empirically defining and calibrating the index of image sharpness; by letting the overall focusing strategy vary depending on user-specified parameters; and by fine-tuning the fuzzy rules, set definitions, and procedures used
Self-Injurious Behaviours in Autism: A Literature Review
Self-injury is a frequent and serious problem for individuals with
autism and developmental disabilities. This paper summarizes the
clinical and empirical evidence pertaining to self-injury, and
highlights valid theories and treatment options. Unlike most
reviews of self-injury, the present one pays particular attention to
the impact that research has made within the field of autism
treatment. The importance of prospective large-scale research is
stressed to support the development of treatments that should
alleviate or even prevent the primary causes of self-injurious
behaviour. This review aims to impart readers with an
unambiguous conceptualization of self-injury and hopes to
stimulate further research within the field
The Poor Kid
Juvenile law and lore present a series of real contradictions. An enormous mound of articles deal with the field, but there are only two Supreme Court cases directly on the question of juvenile rights in the juvenile court process. We have been exhorted time and time again to trust the state as a loving parent who has the child\u27s best interests at heart. But many scholars have documented the horrors that a juvenile actually experiences in the state\u27s dealings with him. Some judges too have recognized these horrors
Transdiagnostic Case Conceptualization of Emotional Problems in Youth with ASD: An Emotion Regulation Approach
DOI: 10.1111/cpsp.12084Youth with autism spectrum disorder often struggle to cope with co-occurring anxiety, depression, or anger, and having both internalizing and externalizing symptoms is a common clinical presentation. A number of authors have designed cognitive-behavioral interventions
to address transdiagnostic factors related to multiple emotional problems, although none have applied this focus to youth with ASD. The current review article describes how a transdiagnostic emotion regulation framework may inform cognitive-behavioral interventions
for youth with ASD, which until now have focused almost exclusively on anxiety. Research is needed to empirically test how a transdiagnostic intervention can address the processes of emotion regulation and assist youth with ASD to cope with their emotional disorders.Canadian Institutes of Health Research, NeuroDevNet, Sinneave Family Foundation, CASDA, Autism Speaks Canada, Health Canada, Spectrum of Hope Autism Foundation, Ontario Mental Health Foundation
Bucci: Chiesa e Stato: Church-State Relations in Italy Within the Contemporary Constitutional Framework
A Review of Chiesa e State: Church-State Relations in Italy Within the Contemporar
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