8 research outputs found

    Microscopic Origin of the Hofmeister Effect in Gelation Kinetics of Colloidal Silica.

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    The gelation kinetics of silica nanoparticles is a central process in physical chemistry, yet it is not fully understood. Gelation times are measured to increase by over 4 orders of magnitude, simply changing the monovalent salt species from CsCl to LiCl. This striking effect has no microscopic explanation within current paradigms. The trend is consistent with the Hofmeister series, pointing to short-ranged solvation effects not included in the standard colloidal (DLVO) interaction potential. By implementing a simple form for short-range repulsion within a model that relates the gelation timescale to the colloidal interaction forces, we are able to explain the many orders of magnitude difference in the gelation times at fixed salt concentration. The model allows us to estimate the magnitude of the non-DLVO hydration forces, which dominate the interparticle interactions on the length scale of the hydrated ion diameter. This opens the possibility of finely tuning the gelation time scale of nanoparticles by just adjusting the background electrolyte species.We acknowledge financial support from: Unilever Plc (E.S.); the Ernest Oppenheimer Fellowship at Cambridge (to 1st June 2014), and by the Technische Universität München Institute for Advanced Study, funded by the German Excellence Initiative and the European Union Seventh Framework Programme under grant agreement 291763 (A.Z.); the Winton Programme for the Physics of Sustainability (B.O.C.).This is the accepted manuscript. The final version is available at http://pubs.acs.org/doi/abs/10.1021/acs.jpclett.5b01300

    !CHAOS: A cloud of controls

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    The paper is aimed to present the !CHAOS open source project aimed to develop a prototype of a national private Cloud Computing infrastructure, devoted to accelerator control systems and large experiments of High Energy Physics (HEP). The !CHAOS project has been financed by MIUR (Italian Ministry of Research and Education) and aims to develop a new concept of control system and data acquisition framework by providing, with a high level of abstraction, all the services needed for controlling and managing a large scientific, or non-scientific, infrastructure. A beta version of the !CHAOS infrastructure will be released at the end of December 2015 and will run on private Cloud infrastructures based on OpenStack

    Present clinical practice of breast cancer radiotherapy in Italy: a nationwide survey by the Italian Society of Radiotherapy and Clinical Oncology (AIRO) Breast Group

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    Aims: To investigate the present attitude of the Italian Radiation Oncologists in the management of breast cancer (BC) concerning hypofractionated radiotherapy (hRT), partial-breast irradiation (PBI), re-irradiation (rRT) and radiotherapy after neoadjuvant chemotherapy (post-NAC RT). Methods: A nationwide, 21-point questionnaire was distributed online via SurveyMonkey. Results: Seventy-four Italian Radiotherapy Centers answered to the survey. In most cases, the responding centers treated more than 100 BC patients/year between January 2016 and December 2017. Almost half of responding centers (49%) treated patients with hRT,out of these, 95% as routine practice for early-stage BC. Dose prescriptions ranged between 39 and 45 Gy indicating a high use of moderate hRT. The chest wall and regional lymph nodes were irradiated with hRT by 13% and 15% of the responding centers, respectively. PBI was used by 60% of responders, with different techniques. Only 0.6% of participants perform rRT after BC recurrence.Finally, only 11% of the interviewed centers responded to their attitude toward post-NAC RT, which, however, was indicated in 97% of patients after breast-conserving surgery. Conclusions: This survey shows a fairly good use of hRT and a moderate practice of PBI in Italy. Some practices like hRT to the chest wall and regional lymph nodes as well as rRT need further verification. Likewise, the management of post-NAC RT is very heterogeneous. Future national clinical collaborative studies are advocated in order to investigate these controversial topics about breast cancer radiotherapy

    Dynamic properties of interfaces in soft matter: Experiments and theory

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