66 research outputs found
Two-point theory for the differential self-interrogation Feynman-alpha method
A Feynman-alpha formula has been derived in a two region domain pertaining
the stochastic differential self-interrogation (DDSI) method and the
differential die-away method (DDAA). Monte Carlo simulations have been used to
assess the applicability of the variance to mean through determination of the
physical reaction intensities of the physical processes in the two domains.
More specifically, the branching processes of the neutrons in the two regions
are described by the Chapman - Kolmogorov equation, including all reaction
intensities for the various processes, that is used to derive a variance to
mean relation for the process. The applicability of the Feynman-alpha or
variance to mean formulae are assessed in DDSI and DDAA of spent fuel
configurations.Comment: 15 pages, 5 figures. Submitted to EPJ Plu
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In-plant test and evaluation of the neutron collar for verification of PWR fuel assemblies at Resende, Brazil
The neutron-coincidence collar has been evaluated for the measurement of pressurized-water reactor (PWR) fuel assemblies at the Fabrica de Elementos Combustiveis plant in Resende, Brazil. This evaluation was part of the cooperative-bilateral-safeguards technical-exchange program between the United States and Brazil. The neutron collar measures the STVU content per unit length of full fuel assemblies using neutron interrogation and coincidence counting. The STYU content is measured in the passive mode without the AmLi neutron-interrogation source. The extended evaluation took place over a period of 6 months with both scanning and single-zone measurements. The results of the tests gave a coincidence-response standard deviation of 0.7% (sigma = 1.49% for mass) for the active case and 2.5% for the passive case in 1000-s measurement times. The length measurement in the scanning mode was accurate to 0.77%. The accuracies of different calibration methods were evaluated and compared
Cognitive dysfunction in naturally occurring canine idiopathic epilepsy
Globally, epilepsy is a common serious brain disorder. In addition to seizure activity, epilepsy is associated with cognitive impairments including static cognitive impairments present at onset, progressive seizure-induced impairments and co-morbid dementia. Epilepsy occurs naturally in domestic dogs but its impact on canine cognition has yet to be studied, despite canine cognitive dysfunction (CCD) recognised as a spontaneous model of dementia. Here we use data from a psychometrically validated tool, the canine cognitive dysfunction rating (CCDR) scale, to compare cognitive dysfunction in dogs diagnosed with idiopathic epilepsy (IE) with controls while accounting for age. An online cross-sectional study resulted in a sample of 4051 dogs, of which n = 286 had been diagnosed with IE. Four factors were significantly associated with a diagnosis of CCD (above the diagnostic cut-off of CCDR â„50): (i) epilepsy diagnosis: dogs with epilepsy were at higher risk; (ii) age: older dogs were at higher risk; (iii) weight: lighter dogs (kg) were at higher risk; (iv) training history: dogs with more exposure to training activities were at lower risk. Impairments in memory were most common in dogs with IE, but progression of impairments was not observed compared to controls. A significant interaction between epilepsy and age was identified, with IE dogs exhibiting a higher risk of CCD at a young age, while control dogs followed the expected pattern of low-risk throughout middle age, with risk increasing exponentially in geriatric years. Within the IE sub-population, dogs with a history of cluster seizures and high seizure frequency had higher CCDR scores. The age of onset, nature and progression of cognitive impairment in the current IE dogs appear divergent from those classically seen in CCD. Longitudinal monitoring of cognitive function from seizure onset is required to further characterise these impairments
Treating anxiety after stroke (TASK): the feasibility phase of a novel web-enabled randomised controlled trial
TiDier template items. (DOCX 28 kb
A Three Year Study of Special Educator Attrition: WhyThey Leave and Where They Go
With chronic and critical shortages of special education professionals evident throughout the United States, the issues of attrition and retention are on the forefront of analysis. Reasons why special education professionals in Utah left their positions were explored in a three-year study of special education attrition. The causes and patterns of attrition have been analyzed, giving valuable insight into how the loss of qualified special education professionals can be prevented. The most common reason for leaving listed by special education teachers and speech language pathologists was that they âmoved out of stateâ. School psychologists reported âretirementâ and âmoved out of stateâ as their two most common reasons for leaving public school positions. The most common reasons for leaving listed by all special education professionals were âmoved out of stateâ, âretiredâ, and âtransferred to general educationâ. Moving and retiring are most likely not preventable, however, assisting special educators who move to obtain positions as they relocate may be an effective method of retaining them in the field of special education. Preventable attrition such as transferring to general education and changing school districts could be addressed by university faculty and school administrators to better understand why special educators transfer and what can be done to prevent the transfers. This understanding could lead to improved strategies to minimize attrition and promote retention of special education professionals
Special Education Teacher Attrition: How Many AreLeaving? Where Are They Going?
A statewide survey was conducted to determine the number of special education teachers leaving positions in Utah between February 1, 1998 and January 31, 1999. Reasons for leaving were also identified in order to infer possible retention strategies. Findings indicated at 238 special education teachers (9.3%) left their jobs during the one-year period. It was estimated that approximately 9% of this number might have been retained with corrective action. Main reasons for the preventable attrition included transfers to general education and resignations for personal reasons. In-depth research is needed to identify more specific factors underlying special education teacher attrition
Effects of Peer Coaching on the Acquisition of Direct Instruction Skills with Low-Performing Preservice Teachers
We examined the effects of peer coaching, a method of supervising preservice teacher trainees who were learning to deliver direct instruction procedures to small groups of elementary-age students with mild disabilities. Coaches helped five low-performing trainees acquire effective teaching behaviors by (a) evaluating videotapes of their teaching performance, (b) meeting individually with trainees to review videotapes, (c) helping trainees evaluate their own performance, (d) providing feedback on effective and ineffective behaviors, (e) setting objectives for improved performance, and (f) periodically grading performance. The effects of peer coaching were examined in a multiple baseline design across trainees. Results indicated that peer coaching increased the effective teaching behaviors of five trainees
Technology-MediatedConsultation to Assist Rural Students: A Case Study
Emerging videoconferencing technologies permit face to face communication in a virtual, real time manner so that educational expertise can be shared across geographical boundaries. Although demonstrations of successful use of videoconferencing to share expertise of teachers and related service personnel go back 20 years, the sustained use of technology for this purpose has yet to occur. This paper describes a case study in which consultation was delivered to a special education classroom in a remote region to help develop and implement the IEP for a young child with autism. While there was a clear benefit to the child in this case, collateral technological and programmatic challenges were never fully overcome, thus shortcutting the intended intervention. Issues that must be resolved for families and local education agency personnel to benefit from the expertise of consultants at a distance are discussed
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