Powder fed sheared dispersal particle generator

A particle generating system is described which is capable of breaking up agglomerations of particles and producing a cloud of uniform, submicron-sized particles at high pressure and high flow rates. This is achieved by utilizing a tubular structure which has injection microslits on is periphery to accept and disperse the desired particle feed. By suppling a carrying fluid at a pressure, of approximately twice the ambient pressure of the velocimeter's settling chamber, the microslits operate at choked flow conditions. The shearing action of this choked flow is sufficient to overcome interparticle bonding forces, thereby breaking up the agglomerates of the particles feed into individual particles

Computer program analyzes Buckling Of Shells Of Revolution with various wall construction, BOSOR

Computer program performs stability analyses for a wide class of shells without unduly restrictive approximations. The program uses numerical integration, finite difference of finite element techniques to solve with reasonable accuracy almost any buckling problem for shells exhibiting orthotropic behavior

Buckling of shells of revolution with various wall constructions. Volume 1 - Numerical results

Numerical results of buckling of shells of revolution for computer progra

Buckling of shells of revolution with various wall constructions. Volume 3 - User's manual for BOSOR

Computer program for analysis of shells of revolution with axisymmetric loadin

Buckling of shells of revolution with various wall constructions. Volume 2 - Basic equations and method of solution

Basic equations and method of solution for computerized analysis of shells of revolution with axisymmetric collapse and nonsymmetric bifurcation buckling behavio

Compliant Wall Surface Motion and its Effect on the Structure of a Turbulent Boundary Layer

The status of the continuing compliant wall drag reduction research at NASA-Langley Research Center is discussed. Preliminary surface motion calculations are reported along with compliant surface design concepts and their numerical models. A compliant drag reduction theory based on stabilizing the turbulent substructure is proposed and previous experiments have been examined relative to that theory. Results of recent low speed compliant surface experiments have been reported which include initial attempts to measure local compliant surface motion

The nature and prevalence of psychological problems in New Zealand primary healthcare: a report on Mental Health and General Practice Investigation ( MaGPIe)

Aims This paper describes the methods used in a study of the prevalence and types of common mental disorders among patients attending New Zealand general practices, and reports some key findings from the first phase of the study. The study also aimed to determine the degree of associated disability and other factors influencing recognition, management, course and outcome of these disorders, and subsequent papers will address these issues. Methods General practitioners (GPs) were selected randomly. In the first phase of the study, all adult attenders at each practice on selected days were administered a short questionnaire, the General Health Questionnaire (GHQ-12), which screens for psychological symptoms. The GP recorded the reasons for each consultation, and was interviewed at the end of each day about selected patients to determine their opinion about the type of psychological problems experienced. Selected patients were then visited in their own homes and an extensive interview conducted, which included the Composite International Diagnostic Interview (CIDI) to determine mental health status, the World Health Organization’s Disability Assessment Schedule (WHODAS) to determine disability, and a detailed exploration of use of health services. In the second phase of the study, patients were contacted by telephone at three, six, nine and 12 months, and both patients and GPs were re-interviewed at 12 months. Results The study achieved a very high response rate among the GPs (90%). Nearly all eligible patients (93%) completed the GHQ screening, and their response rate was 70% for the first-phase interview. GPs thought that 54% of female and 46% of male patients had experienced some level of psychological problems in the past year. GHQ screening also found that more than half of those attending their general practitioner experienced some psychological symptoms at initial screening, and the CIDI interview found that more than one in three had a diagnosable mental disorder during the past 12 months. The most common mental disorders were depressive, anxiety and substance use disorders. These disorders were more common among younger than older general practice attenders, and comorbidity was high. Conclusions Mental health problems are very common among general practice attenders. Contrary to the prevailing view that general practitioners seldom identify psychological problems in their patients, they identified about half their patients as having some type of psychological problems in the past year, although they considered that these were moderate or severe in about only one in ten patients. Further work from this large New Zealand study will focus on the nature of the relationship between disorder and disability, and on the recognition, management and outcome of psychological problems

Touch and look: the role of visual-haptic cues for categorical learning in children

Benefits of synchronous presentation of multisensory compared to unisensory cues are well established. However, the generality of such findings to children’s learning with visual and haptic sensory cue pairings is unclear. Children aged six to ten years (N=180) participated in a novel table-top category learning paradigm with visual, haptic or visuo-haptic informative cues. The results indicated that combinations of complimentary visual and haptic cues facilitated learning above unisensory visual cues only in 8-year-old children. Primarily, however, haptic information was found to dominate children’s category learning across ages, particularly in the youngest children (six-year-olds), even with equal discriminability of haptic and visual exemplars. These findings suggest developmental changes in the ability to effectively combine un-related visual and haptic information for categorical learning. Implications for the use of non-pertinent visuohaptic cues in learning tasks within educational settings at different ages, and in particular the dominance of haptic stimuli for children’s learning are discussed

Asymptotics and local constancy of characters of p-adic groups

In this paper we study quantitative aspects of trace characters $\Theta_\pi$ of reductive $p$-adic groups when the representation $\pi$ varies. Our approach is based on the local constancy of characters and we survey some other related results. We formulate a conjecture on the behavior of $\Theta_\pi$ relative to the formal degree of $\pi$, which we are able to prove in the case where $\pi$ is a tame supercuspidal. The proof builds on J.-K.~Yu's construction and the structure of Moy-Prasad subgroups.Comment: Proceedings of Simons symposium on the trace formul

Exploring the longitudinal relationships between the use of grammar in text messaging and performance on grammatical tasks

Research has demonstrated that use of texting slang (textisms) when text messaging does not appear to impact negatively on children's literacy outcomes and may even benefit children's spelling attainment. However, less attention has been paid to the impact of text messaging on the development of children's and young people's understanding of grammar. This study therefore examined the interrelationships between children's and young adults' tendency to make grammatical violations when texting and their performance on formal assessments of spoken and written grammatical understanding, orthographic processing and spelling ability over the course of 1 year. Zero-order correlations showed patterns consistent with previous research on textism use and spelling, and there was no evidence of any negative associations between the development of the children's performance on the grammar tasks and their use of grammatical violations when texting. Adults' tendency to use ungrammatical word forms ('does you') was positively related to performance on the test of written grammar. Grammatical violations were found to be positively associated with growth in spelling for secondary school children. However, not all forms of violation were observed to be consistently used in samples of text messages taken 12 months apart or were characteristic of typical text messages. The need to differentiate between genuine errors and deliberate violation of rules is discussed, as are the educational implications of these findings