Force balance in canonical ensembles of static granular packings

We investigate the role of local force balance in the transition from a microcanonical ensemble of static granular packings, characterized by an invariant stress, to a canonical ensemble. Packings in two dimensions admit a reciprocal tiling, and a collective effect of force balance is that the area of this tiling is also invariant in a microcanonical ensemble. We present analytical relations between stress, tiling area and tiling area fluctuations, and show that a canonical ensemble can be characterized by an intensive thermodynamic parameter conjugate to one or the other. We test the equivalence of different ensembles through the first canonical simulations of the force network ensemble, a model system.Comment: 9 pages, 9 figures, submitted to JSTA

Soft Sphere Packings at Finite Pressure but Unstable to Shear

When are athermal soft sphere packings jammed ? Any experimentally relevant definition must at the very least require a jammed packing to resist shear. We demonstrate that widely used (numerical) protocols in which particles are compressed together, can and do produce packings which are unstable to shear - and that the probability of generating such packings reaches one near jamming. We introduce a new protocol that, by allowing the system to explore different box shapes as it equilibrates, generates truly jammed packings with strictly positive shear moduli G. For these packings, the scaling of the average of G is consistent with earlier results, while the probability distribution P(G) exhibits novel and rich scalingComment: 5 pages, 6 figures. Resubmitted to Physical Review Letters after a few change

Assessment of cooling methods for increased power density in electrical machines

A comprehensive thermal analysis of three different electrical machines is presented, with a view of identifying design aspects that can be exploited to achieve higher power density. A review of some novel cooling methods is initially made. Following this, the stator and rotor thermal resistance paths of the three selected machines are created and the individual components of each resistance path mathematically analysed to identify the parts of the machines that provide greatest potential to reduce stator and rotor temperatures. This is verified with a Design of Experiments analysis on the thermal resistance models of each. Finally, a different novel cooling method is applied to the model of each machine, demonstrating the typical temperature reductions that can be achieved

Model for the Scaling of Stresses and Fluctuations in Flows near Jamming

We probe flows of soft, viscous spheres near the jamming point, which acts as a critical point for static soft spheres. Starting from energy considerations, we find nontrivial scaling of velocity fluctuations with strain rate. Combining this scaling with insights from jamming, we arrive at an analytical model that predicts four distinct regimes of flow, each characterized by rational-valued scaling exponents. Both the number of regimes and values of the exponents depart from prior results. We validate predictions of the model with simulations.Comment: 4 pages, 5 figures (revised text and one new figure). To appear in Phys. Rev. Let

Walking the Talk: Doing Science with Perimenopausal Women and their Health Care Providers

Perimenopausal high estrogen levels amplify the social stress of changing reproductive status in a culture that places value on women’s youth and beauty. As it was realized that progesterone physiologically counterbalances the effects of estrogen, it would be better to use progesterone, rather than estrogen for appropriate therapy of perimenopause. Based on this new knowledge was designed a three-arm study project comparing the recommended therapy, low dose OC (oral contraceptives) against progesterone therapy. In the pilot project cooperated Health Care Providers (HCP), by whose help was assembled eleven domains, which perimenopausal women find the most problematic. These HCP were also providing consultations for women with these problems, what gave to the women a good chance of self-analyses of their experience, and to HCP knowledge that the participation with their patients can bring something new into their practice

IgE autoantibodies and their association with the disease activity and phenotype in Bullous Pemphigoid: a systematic review

Bullous Pemphigoid (BP) is the most common autoimmune skin disease of blistering character. The underlying pathophysiological mechanism involves an immune attack, usually by IgG class autoantibodies, on the autoantigen BP 180/BPAg2, which is a type XVII collagen (COL17) protein acting as the adhesion molecule between the epidermis and the basement membrane of the dermis. About 40 years ago, following consistent findings of elevated total serum IgE levels in BP patients, it was hypothesized that IgE may be involved in the pathophysiology of BP. Our objective was to determine whether there is strong evidence for an association between IgE class autoantibodies and the clinical severity or phenotype of BP. Three databases were searched for relevant studies and appropriate exclusion and inclusion criteria were applied. Data was extracted and assessed in relation to the study questions concerning the clinical significance of IgE autoantibodies in BP. Nine studies found that anti-BP180 autoantibodies of IgE class are associated with increased severity of BP, whereas two studies did not find such an association. The number of studies which found an association between higher IgE autoantibody levels and the erythematous urticarial phenotype of BP (5) were equal in number to the studies which found no such association (5). In conclusion, higher serum IgE autoantibody levels are associated with more severe clinical manifestations of BP. There is insufficient evidence to support higher IgE autoantibody levels being associated with specific clinical phenotypes of BP

Cigarette smoking differentially affects immunoglobulin class levels in serum and saliva: An investigation and review

The aim of the present study was to compare concentrations of IgG, IgA, IgM and IgD in both serum and saliva samples from smoking and non-smoking subjects using a protein microarray assay. The findings were also compared to previous studies. Serum and saliva were collected from 48 smoking male subjects and 48 age-matched neversmoker male subjects. The protein microarray assays for detection of human IgG, IgM, IgA and IgD were established and optimized using Ig class-specific affinity purified goat anti-human Ig-Fc capture antibodies and horseradish peroxidase (HRP)- conjugated goat anti-human Ig-Fc detection antibodies. The Ig class specificity of the microarray assays was verified and the optimal dilutions of serum and saliva samples was determined for quantification of Ig levels against standard curves. We found that smoking is associated with reduced IgG concentrations and enhanced IgA concentrations in both serum and saliva. By contrast, smoking differentially affected IgM concentrations – causing increased concentrations in serum, but decreased concentrations in saliva. Smoking was associated with decreased IgD concentrations in serum, and did not have a significant effect on the very low IgD concentrations in saliva. Thus, cigarette smoking differentially affects the levels of Ig classes systemically and in the oral mucosa. Although there is variation between the results of different published studies, there is a consensus that smokers have significantly reduced levels of IgG in both serum and saliva. A functional antibody deficiency associated with smoking may compromise the body’s response to infection and result in a predisposition to the development of autoimmunity

TRA-961: FOAM GLASS LIGHTWEIGHT AGGREGATE: THE NEW APPROACH

Foam glass lightweight aggregate (LWA) derived from mixed waste and recycled glass has great potential for use as an alternative material for several applications in building and other industrial applications. Despite the significant superior features of the current product, there is still room for further research to improve the structural performance of newly developed foam glass and foam glass-ceramics produced from waste and recycled materials. Improvements may be achieved through controlling microstructures and the distributions of pore sizes and shapes, altering chemical and phase compositions, creating reinforced structures by the inclusion of other fibrous materials as well as adding colour to the foam glass and glass-ceramics. One commercially used foam glass gravel has been selected and was the subject of a wide range of tests to determine its physical and mechanical properties and to compare them to conventional products in the industry. Results obtained from percent crushed particle content, abrasion resistance and freezing and thawing resistance testing are presented and analysed. Methods for improving foam properties and expanding its usefulness in engineering applications are proposed; adjusting the microstructure characteristics and changing the chemical and phase composition were found to be effective. A deeper examination of the microstructure by microscopy (SEM or TEM) further revealed the promising features of the evaluated material as a new versatile construction material. In addition, inclusion of colouring oxides in foam formulation was examined as an innovative way for increasing mechanical strength in a colourful product