Long lasting instabilities in granular mixtures

We have performed experiments of axial segregation in the Oyama's drum. We have tested binary granular mixtures during very long times. The segregation patterns have been captured by a CCD camera and spatio-temporal graphs are created. We report the occurence of instabilities which can last several hours. We stress that those instabilities originate from the competition between axial and radial segregations. We put into evidence the occurence of giant fluctuations in the fraction of grain species along the surface during the unstable periods.Comment: 10 pages, 10 figures, (2002

Block to granular-like transition in dense bubble flows

We have experimentally investigated 2-dimensional dense bubble flows underneath inclined planes. Velocity profiles and velocity fluctuations have been measured. A broad second-order phase transition between two dynamical regimes is observed as a function of the tilt angle $\theta$. For low $\theta$ values, a block motion is observed. For high $\theta$ values, the velocity profile becomes curved and a shear velocity gradient appears in the flow.Comment: Europhys. Lett. (2003) in pres

The impact of psoriasis on wellbeing and clinical outcomes in juvenile psoriatic arthritis

Objectives: Juvenile psoriatic arthritis (JPsA) has varied clinical features that are distinctive to other juvenile idiopathic arthritis (JIA) categories. This study investigates whether such features impact patient-reported and clinical outcomes. // Methods: Children and young people (CYP) were selected if recruited to the Childhood Arthritis Prospective Study, a UK multicentre JIA inception cohort, between January 2001 and March 2018. At diagnosis, patient/parent-reported outcomes (as age-appropriate) included the parental global assessment (10 cm VAS), functional ability (CHAQ), pain (10 cm VAS), health-related quality of life (CHQ psychosocial score), mood/depressive symptoms (MFQ) and parent psychosocial health (GHQ). Three-year outcome trajectories have previously been defined using active joint counts, physician and parent global assessments (PGA, PaGA respectively). Patient-reported outcomes and outcome trajectories were compared in i) CYP with JPsA versus other JIA categories, ii) CYP within JPsA, with and without psoriasis via multivariable linear regression. // Results: There were no significant differences in patient-reported outcomes at diagnosis between CYP with JPsA and non-JPsA. Within JPsA, those with psoriasis had more depressive symptoms (coefficient = 9.8, 95% CI = 0.5–19.0) than those without psoriasis at diagnosis. CYP with JPsA had 2.3 times the odds of persistent high PaGA than other ILAR categories, despite improving joint counts and PGA (95% CI 1.2, 4.6). // Conclusion: CYP with psoriasis at JPsA diagnosis report worse mood, supporting a greater disease impact in those with both skin and joint involvement. Multidisciplinary care with added focus to support wellbeing in children with JPsA plus psoriasis may help improve these outcomes

Resorcinol-Formaldehyde and Carbon Aerogel Microspheres

Aerogels are a unique class of materials possessing an open-cell structure with ultrafine cells/pores (<100nm), high surface area (400--1100 m{sup 2}/g), and a solid matrix composed of interconnected particles, fibers, or platelets with characteristic dimensions of 10nm. Although monolithic aerogels are ideal candidates for many applications (e.g. transparent window insulation), current processing methods have limited their introduction into the commercial marketplace. Our research focuses on the formation of resorcinol-formaldehyde (RF) aerogel microspheres which offer an attractive alternative to monolith production. An inverse emulsion polymerization is used to produce these spherical gel particles which undergo solvent exchange followed by supercritical drying with carbon dioxide. This process yields aerogel microspheres (10--80{mu} diameter) which can be used as loosely packed powders, compression molded into near-net shapes using a polymer binder, or used as additives in conventional foaming operations to produce new aerogel composites with superior thermal properties. The emulsification procedure, thermal characterization, mechanical properties, and potential applications of RF aerogel microspheres will be discussed

Vacuum insulation panels (VIPs) for use in buildings

Through the ReCO2ST project, vacuum insulation panels have been installed on the demonstration building at Brunel University London and are being monitored for thermophysical performance. First results show monthly average temperatures in the range of 12.8 °C – 15.8 °C between the wall and the insulation layer when monthly average ambient temperature was 5.6 °C. A new submicron-scale polymer foam has been characterized for use in vacuum insulation panels. FT-IR results regarding radiative conductivity and specific extinction with and without graphite opacifier are presented. The thermal conductivity as function of gas pressure has also been investigated. This new materials has achieved a thermal conductivity of approximately 5 mW/(m∙K) under vacuum, similar to fumed silica. Thermal conductivity doubles at gas pressure of 50 mbar, making it less suitable as core material for long term applications unlike fumed silica, but more suitable than other known core material alternatives such as polyurethane or glass fiber.European Union’s Horizon 2020 research and innovation programme under grant agreement No 748256 and No 768576

Probing the role of atomic defects in photocatalytic systems through photoinduced enhanced raman scattering

Even in ultralow quantities, oxygen vacancies (VO) drastically impact key properties of metal oxide semiconductors, such as charge transport, surface adsorption, and reactivity, playing central roles in functional materials performance. Current methods used to investigate VO often rely on specialized instrumentation under far from ideal reaction conditions. Hence, the influence of VO generated in situ during catalytic processes has yet to be probed. In this work, we assess in situ extrinsic surface VO formation and lifetime under photocatalytic conditions which we compare to photocatalytic performance. We show for the first time that lifetimes of in situ generated atomic VO play more significant roles in catalysis than their concentration, with strong correlations between longer-lived VO and higher photocatalytic activity. Our results indicate that enhanced photocatalytic efficiency correlates with goldilocks VO concentrations, where VO densities must be just right to encourage carrier transport while avoiding charge carrier trapping

Identification of Novel Susceptibility Loci and Genes for Prostate Cancer Risk: A Transcriptome-Wide Association Study in over 140,000 European Descendants

Genome-wide association study–identified prostate cancer risk variants explain only a relatively small fraction of its familial relative risk, and the genes responsible for many of these identified associations remain unknown. To discover novel prostate cancer genetic loci and possible causal genes at previously identified risk loci, we performed a transcriptome-wide association study in 79,194 cases and 61,112 controls of European ancestry. Using data from the Genotype-Tissue Expression Project, we established genetic models to predict gene expression across the transcriptome for both prostate models and cross-tissue models and evaluated model performance using two independent datasets. We identified significant associations for 137 genes at P < 2.61 × 10−6, a Bonferroni-corrected threshold, including nine genes that remained significant at P < 2.61 × 10−6 after adjusting for all known prostate cancer risk variants in nearby regions. Of the 128 remaining associated genes, 94 have not yet been reported as potential target genes at known loci. We silenced 14 genes and many showed a consistent effect on viability and colony-forming efficiency in three cell lines. Our study provides substantial new information to advance our understanding of prostate cancer genetics and biology. SIGNIFICANCE: This study identifies novel prostate cancer genetic loci and possible causal genes, advancing our understanding of the molecular mechanisms that drive prostate cancer