Triangular buckling patterns of twisted inextensible strips

When twisting a strip of paper or acetate under high longitudinal tension, one observes, at some critical load, a buckling of the strip into a regular triangular pattern. Very similar triangular facets have recently been observed in solutions to a new set of geometrically-exact equations describing the equilibrium shape of thin inextensible elastic strips. Here we formulate a modified boundary-value problem for these equations and construct post-buckling solutions in good agreement with the observed pattern in twisted strips. We also study the force-extension and moment-twist behaviour of these strips by varying the mode number n of triangular facets

Wind Tunnel Experimentation on Stationary Downbursts at WindEEE Dome

In the context of the European Project THUNDERR a scientific collaboration between the Wind Engineering and Structural Dynamics (Windyn) Research Group of the University of Genoa (Italy) and the Wind Engineering, Energy and Environment (WindEEE) Research Institute of Western University (Canada) has been established to study experimentally at the WindEEE Dome facility how the main geometrical and mechanical properties of downbursts are affected by different cloud base outflows of stationary thunderstorms. At present, the analysis of the downbursts simulated experimentally is ongoing and some preliminary elaborations have been obtained concerning the qualitative and quantitative interpretation of the corresponding signals. Classical signal decomposition was applied to experimentally produced downbursts in the WindEEE Dome in order to study transient features of the time series. This study presents the results for two radial positions from downdraft centre and for twenty repetitions per radial position. Several prospects for further research are also discussed

A novel approach to scaling experimentally produced downburst-like impinging jet outflows

Downbursts are intense thunderstorm winds that can be found in most, if not all, regions around the globe. An accurate experimental investigation of downburst winds requires the proper geometric and kinematic scaling between the model downburst (m) created in a wind simulator and the full scale downburst event (p). This study makes a threefold contribution to further understanding of downburst outflows. First, the article introduces a new scaling methodology for downburst outflows based on the signal decomposition techniques of p and m downburst wind records. Second, the study describes a large set of m downbursts produced in the WindEEE Dome simulator at Western University and critically discusses their similarity with a large set of p events detected in the Mediterranean. Third, using the proposed scaling methodology, this paper attempts to partially reconstruct two p downburst events recorded in Genoa and Livorno, Italy. In total, 17 p and 1400 m downburst outflows are investigated herein, which represents the largest database of p and m downbursts combined. The similarity between p and m downbursts is quantitatively demonstrated for both mean and fluctuating components of the flows. The scaling method is verified by accurately predicting the known anemometer height of p events using m downburst measurements

Trigonometry of 'complex Hermitian' type homogeneous symmetric spaces

This paper contains a thorough study of the trigonometry of the homogeneous symmetric spaces in the Cayley-Klein-Dickson family of spaces of 'complex Hermitian' type and rank-one. The complex Hermitian elliptic CP^N and hyperbolic CH^N spaces, their analogues with indefinite Hermitian metric and some non-compact symmetric spaces associated to SL(N+1,R) are the generic members in this family. The method encapsulates trigonometry for this whole family of spaces into a single "basic trigonometric group equation", and has 'universality' and '(self)-duality' as its distinctive traits. All previously known results on the trigonometry of CP^N and CH^N follow as particular cases of our general equations. The physical Quantum Space of States of any quantum system belongs, as the complex Hermitian space member, to this parametrised family; hence its trigonometry appears as a rather particular case of the equations we obtain.Comment: 46 pages, LaTe

Assessing the efficacy of a modified assertive community-based treatment programme in a developing country

<p>Abstract</p> <p>Background</p> <p>A number of recently published randomized controlled trials conducted in developed countries have reported no advantage for assertive interventions over standard care models. One possible explanation could be that so-called "standard care" has become more comprehensive in recent years, incorporating some of the salient aspects of assertive models in its modus operandi. Our study represents the first randomised controlled trial assessing the effect of a modified assertive treatment service on readmission rates and other measures of outcome in a developing country.</p> <p>Methods</p> <p>High frequency service users were randomized into an intervention (n = 34) and a control (n = 26) group. The control group received standard community care and the active group an assertive intervention based on a modified version of the international model of assertive community treatment. Study visits were conducted at baseline and 12 months with demographic and illness information collected at visit 1 and readmission rates documented at study end. Symptomatology and functioning were measured at both visits using the PANSS, CDSS, ESRS, WHO-QOL and SOFAS.</p> <p>Results</p> <p>At 12 month follow-up subjects receiving the assertive intervention had significantly lower total PANSS (p = 0.02) as well as positive (p < 0.01) and general psychopathology (p = 0.01) subscales' scores. The mean SOFAS score was also significantly higher (p = 0.02) and the mean number of psychiatric admissions significantly lower (p < 0.01) in the intervention group.</p> <p>Conclusions</p> <p>Our results indicate that assertive interventions in a developing setting where standard community mental services are often under resourced can produce significant outcomes. Furthermore, these interventions need not be as expensive and comprehensive as international, first-world models in order to reduce inpatient days, improve psychopathology and overall levels of functioning in patients with severe mental illness.</p

Mixed Climatology, Non-synoptic Phenomena and Downburst Wind Loading of Structures

Modern wind engineering was born in 1961, when Davenport published a paper in which meteorology, micrometeorology, climatology, bluff-body aerodynamics and structural dynamics were embedded within a homogeneous framework of the wind loading of structures called today \u201cDavenport chain\u201d. Idealizing the wind with a synoptic extra-tropical cyclone, this model was so simple and elegant as to become a sort of axiom. Between 1976 and 1977 Gomes and Vickery separated thunderstorm from non-thunderstorm winds, determined their disjoint extreme distributions and derived a mixed model later extended to other Aeolian phenomena; this study, which represents a milestone in mixed climatology, proved the impossibility of labelling a heterogeneous range of events by the generic term \u201cwind\u201d. This paper provides an overview of this matter, with particular regard to the studies conducted at the University of Genova on thunderstorm downbursts