The Livermore Superconducting Levitron

The Livermore Superconducting Levitron contains an 80-cm-diam superconducting ring as well as three pairs of superconducting coils that produce a poloidal field, that are 50, 112, and 160 cm in diameter respectively, and that are located 40 cm above and below the midplane of the ring. Twelve control coils and optical position sensors form a feedback system for maintaining the ring's position. Magnetic damping plates above and below the ring prevent it from making accidental but dangerously violent movements. The ring was successfully tested about a year ago, and the entire system is now undergoing its first operating tests. Construction details and the initial operating results are presented here.     

Physical device modelling of emitter–base junction of In0.52Al0.48As/In0.53Ga0.47As-based SHBTs

This paper aims to evaluate the base–emitter forward characteristics of In_0.52Al_0.48As/In_0.53Ga_0.47As heterojunction bipolar transistors using numerical simulations in Silvaco while comparing results with fabricated devices. Analysis drawn from simulations reveals that in addition to doping, thickness of emitter and spacer region also plays an important role in determining the operational behaviour of device. The thickness of spacer region strongly influences the nature of heterojunction barrier formed that in turn controls the injection efficiency and dictates various recombination mechanisms. Even a few angstroms added to a spacer layer can cause considerable shift in DC characteristics. Methodology of device modelling is first validated by matching simulated results with the experimental measurements of two different structures. Spacer thickness and emitter doping is then varied in each of the structures to comprehensively study the effect of these variations onto important DC figures of merit.     

Burden of disease attributed to anthropogenic air pollution in the United Arab Emirates: Estimates based on observed air quality data

This study quantifies the national burden of disease attributed to particulate matter (PM) and ozone (O₃) in ambient air in the United Arab Emirates (UAE), a rapidly growing nation in which economic development and climatic conditions pose important challenges for air quality management. Estimates of population exposure to these air pollutants are based on observed air quality data from fixed-site monitoring stations. We divide the UAE into small grid cells and use spatial-statistical methods to estimate the ambient pollutant concentrations in each cell based on the observed data. Premature deaths attributed to PM and O₃ are computed for each grid cell and then aggregated across grid cells and over a year to estimate the total number of excess deaths attributable to ambient air pollution. Our best estimate is that approximately 545 (95% CI: 132-1224) excess deaths in the UAE in the year 2007 are attributable to PM in ambient air. These excess deaths represent approximately 7% (95% CI: 2-17%) of the total deaths that year. We attribute approximately 62 premature deaths (95% CI: 17-127) to ground-level O₃ for the year 2007. Uncertainty in the natural background level of PM, due to the frequent dust storms occurring in the region, has significant impacts on the attributed mortality estimates. Despite the uncertainties associated with the integrated assessment framework, we conclude that anthropogenic ambient air pollution, in particular PM, causes a considerable public health impact in the UAE in terms of premature deaths. We discuss important uncertainties and scientific hypotheses to be investigated in future work that might help reduce the uncertainties in the burden of disease estimates.     

The effectiveness of functional family therapy for youth with behavioral problems in a community practice setting.

The study examined the effectiveness of Functional Family Therapy (FFT), as compared to probation services, in a community juvenile justice setting 12 months posttreatment. The study also provides specific insight into the interactive effects of therapist model specific adherence and measures of youth risk and protective factors on behavioral outcomes for a diverse group of adolescents. The findings suggest that FFT was effective in reducing youth behavioral problems, although only when the therapists adhered to the treatment model. High-adherent therapists delivering FFT had a statistically significant reduction of (35%) in felony, a (30%) violent crime, and a marginally significant reduction (21%) in misdemeanor recidivisms, as compared to the control condition. The results represent a significant reduction in serious crimes 1 year after treatment, when delivered by a model adherent therapist. The low-adherent therapists were significantly higher than the control group in recidivism rates. There was an interaction effect between youth risk level and therapist adherence demonstrating that the most difficult families (those with high peer and family risk) had a higher likelihood of successful outcomes when their therapist demonstrated model-specific adherence. These results are discussed within the context of the need and importance of measuring and accounting for model specific adherence in the evaluation of community-based replications of evidence-based family therapy models like FFT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A baseline survey of the microbiological quality of chicken portions and carcasses at retail in two Australian states (2005 to 2006)

Raw poultry products were purchased from the retail market place in two Australian states, New South Wales (n = 549) and South Australia (n = 310). The products sampled on a proportional volume basis were chicken portions with the skin off or skin on, in bulk or tray packs, and whole carcasses. They were collected from butcher shops, supermarkets, and specialty stores from urban areas during the winter (2005) and summer (2006) months. The samples were analyzed to determine the prevalence and concentration of Escherichia coli, Salmonella, and Campylobacter spp. in addition to total viable counts. Salmonella was found in 47.7 and 35.5% of retail chicken samples (35.3 and 21.9% were the less virulent Salmonella Sofia), at mean counts of -1.42 and -1.6 log MPN/cm2 in New South Wales and South Australia, respectively. Campylobacter was found in 87.8 and 93.2% of samples at mean counts of 0.87 and 0.78 log CFU/cm2, respectively. In both states in both seasons, the mean total viable count was 5 log CFU/cm2. On whole birds, E. coli was detected in all winter samples and on 92.9 and 85.7% of summer samples in New South Wales and South Australia, respectively; the log of the geometric mean per square centimeter was 0.5 in winter and slightly lower in summer. On chicken portions, E. coli was detected in around 90% of winter samples in both states, and in summer on 75.1 and 59.6% of samples in New South Wales and South Australia, respectively. The log of the geometric mean CFU per square centimeter for E. coli was 0.75 and 0.91 in winter, and 0.66 and 0.5 in summer in New South Wales and South Australia, respectively.     

Defining distinct negative beliefs about uncertainty: Validating the factor structure of the Intolerance of Uncertainty Scale.

This study examined the factor structure of the English version of the Intolerance of Uncertainty Scale (IUS; French version: M. H. Freeston, J. Rhéaume, H. Letarte, M. J. Dugas, & R. Ladouceur, 1994; English version: K. Buhr & M. J. Dugas, 2002) using a substantially larger sample than has been used in previous studies. Nonclinical undergraduate students and adults from the community (M age = 23.74 years, SD = 6.36; 73.0% female and 27.0% male) who participated in 16 studies in the Anxiety Disorders Laboratory at Concordia University in Montreal, Canada were randomly assigned to 2 datasets. Exploratory factor analysis with the 1st sample (n = 1,230) identified 2 factors: the beliefs that “uncertainty has negative behavioral and self-referent implications” and that “uncertainty is unfair and spoils everything.” This 2-factor structure provided a good fit to the data (Bentler-Bonett normed fit index = .96, comparative fit index = .97, standardized root-mean residual = .05, root-mean-square error of approximation = .07) upon confirmatory factor analysis with the 2nd sample (n = 1,221). Both factors showed similarly high correlations with pathological worry, and Factor 1 showed stronger correlations with generalized anxiety disorder analogue status, trait anxiety, somatic anxiety, and depressive symptomatology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An evolutionary innovation perspective on the selection of low and zero-carbon technologies in new housing

The Code for Sustainable Homes will require new homes in the UK to be ‘zero carbon’ from 2016. Drawing upon an evolutionary innovation perspective, a gap in the literature is addressed by investigating which low and zero-carbon technologies are actually being used by house builders, rather than the prevailing emphasis on the potentiality of these technologies. Using the results from a questionnaire, three empirical contributions are made. First, house builders are selecting a narrow range of technologies. Second, these choices are made to minimize the disruption to their standard design and production templates (SDPTs). Finally, the coalescence around a small group of technologies is expected to intensify with solar-based technologies predicted to become more important. A challenge is presented to the dominant technical rationality that assumes technical efficiency and cost benefits are the primary drivers for technology selection. These drivers play an important role, but one which is mediated by the logic of maintaining the SDPTs of the house builders. This emphasizes the need for construction diffusion of innovation theory to be problematized and developed within the context of business and market regimes constrained and reproduced by resilient technological trajectories.     

Utilisation of the MV spectrum for diagnosis and estimation ofharmonic fields

The authors consider the identification of a single channel multidimensional harmonic signal field contained in an unknown and possibly nonstationary noise field. A technique is presented using the convergence-based point spectra developed by Frazho and Sherman (1990, 1991). This technique has the advantage of discerning between point and narrowband noise spectra based on the monotonic convergence properties of a sequence of minimum variance (MV) spectra. Two examples are presented to demonstrate the properties and utility of the approach, also a comparison to the multidimensional discrete Fourier transform and autoregressive modelling techniques