Rheological study of clay-kaolin aqueous suspensions

Rheological characteristics of clay-kaolin aqueous suspensions were studied by a rotational viscometer to correlate their behavior with the properties of ceramic slips for casting containing quartz, feldspars, and other nonplastic materials. In particular, the effects of the different amounts of dry materials and deflocculant (mixture 1:1 of Na2CO3 and Na2SiO3) and of temperatures on the shear-time-dependent properties of suspensions were examined

Breaking degeneracy in jet dynamics: multi-epoch joint modelling of the BL Lac PKS 2155-304

Supermassive black holes can launch powerful jets which can be some of the most luminous multi-wavelength sources; decades after their discovery their physics and energetics are still poorly understood. The past decade has seen a dramatic improvement in the quality of available data, but despite this improvement the semi-analytical modelling of jets has advanced slowly: simple one-zone models are still the most commonly employed method of interpreting data, in particular for AGN jets. These models can roughly constrain the properties of jets but they cannot unambiguously couple their emission to the launching regions and internal dynamics, which can be probed with simulations. However, simulations are not easily comparable to observations because they cannot yet self-consistently predict spectra. We present an advanced semi-analytical model which accounts for the dynamics of the whole jet, starting from a simplified parametrization of Relativistic Magnetohydrodynamics in which the magnetic flux is converted into bulk kinetic energy. To benchmark the model we fit six quasisimultaneous, multi-wavelength spectral energy distributions of the BL Lac PKS 2155-304 obtained by the TANAMI program, and we address the degeneracies inherent to such a complex model by employing a state-of-the-art exploration of parameter space, which so far has been mostly neglected in the study of AGN jets. We find that this new approach is much more effective than a single-epoch fit in providing meaningful constraints on model parameters.Comment: Accepted for publication on MNRA

On the probability of generating a minimal <i>d</i>-generated group

AbstractWe consider finite groups with the property that any proper factor can be generated by a smaller number of elements than the group itself. We study some problems related with the probability of generating these groups with a given number of elements

GENERATION OF UNIFORM HAZARD FLOOR RESPONSE SPECTRA FOR LINEAR MDOF STRUCTURES

This paper presents a probabilistic seismic demand model for predicting the pseudo-acceleration response of a linear nonstructural component attached to a linear structure. The model relates the response of the component with the pseudo-acceleration response of the generic mode of vibration of the supporting structure. Interaction between component and structure is ignored. Independency of the model on the specific characteristics of seismic hazard at the site is showed. The model is used to develop a method for direct generation of uniform hazard floor response spectra. By using the method floor spectra are determined through a closed-form expression, given the mean annual frequency of interest, the non-structural component damping ratio, the modal properties of the structure, and three uniform hazard spectra representing seismic hazard at the site

On the Number of Generators and Composition Length of Finite Linear Groups

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Rituximab in the treatment of immune thrombocytopenia: What is the role of this agent in 2019?

The use of rituximab for the treatment of immune thrombocytopenia was greeted enthusiastically: it led to up to 60% response rates, making it, nearly 20 years ago, the main alternative to splenectomy, with far fewer side effects. However, long-term follow-up data showed that only 20-30% of patients maintained the remission. No significant changes have been registered using different dose schedules and timing of administration, while the combination with other drugs seemed promising. Higher response rates have been observed in young women before the chronic phase, but apart from that, other clinical factors or biomarkers predictive of response are still lacking. In this review we examine the historical and current role of rituximab in the management of immune thrombocytopenia, 20 years after its first use for the treatment of autoimmune diseases

Continuing declines in cancer mortality in the European Union

Background: From 1988 to 1997 age-standardised total cancer mortality rates in the European Union (EU) fell by around 9% in both sexes. Available cancer mortality data in Europe up to 2002 allow a first check of the forecast of further declines in cancer mortality. Patients and methods: We considered trends in age-standardised mortality from major cancer sites in the EU during the period 1980-2002. Results: For men, total cancer mortality, after a peak of 191.1/100 000 in 1987 declined to 177.8 in 1997 (−7%), and to 166.5 in 2002. Corresponding figures for females were 107.9/100 000, 100.5 and 95.2, corresponding to falls of 7% from 1987 to 1997, and to 5% from 1997 to 2002. Over the last 5 years, lung cancer declined by 1.9% per year in men, to reach 44.4/100 000, but increased by 1.7% in women, to reach 11.4. In 2002, for the first year, lung cancer mortality in women was higher than that for intestinal cancer (11.1/100 000), and lung cancer became the second site of cancer deaths in women after breast (17.9/100 000). From 1997 to 2002, appreciable declines were observed in mortality from intestinal cancer in men (−1.6% per year, to reach 18.8/100 000), and in women (−2.5%), as well as for breast (−1.7% per year) and prostate cancer (−1.4%). Conclusions: Despite the persisting rises in female lung cancer, the recent trends in cancer mortality in the EU are encouraging and indicate that an 11% reduction in total cancer mortality from 2000 to 2015 is realistic and possibl

Declining mortality from kidney cancer in Europe

Mortality rates from kidney cancer increased throughout Europe up until the late 1980s or early 1990s. Trends in western European countries, the European Union (EU) and selected central and eastern European countries have been updated using official death certification data for kidney cancer abstracted from the World Health Organisation (WHO) database over the period 1980-1999. In EU men, death rates increased from 3.92 per 100 000 (age standardised, world standard) in 1980-81 to 4.63 in 1994-95, and levelled off at 4.15 thereafter. In women, corresponding values were 1.86 in 1980-81, 2.04 in 1994-95 and 1.80 in 1998-99. Thus, the fall in kidney cancer mortality over the last 5 years was over 10% for both sexes in the EU. The largest falls were in countries with highest mortality in the early 1990s, such as Germany, Denmark and the Netherlands. Kidney cancer rates levelled off, but remained very high, in the Czech Republic, Baltic countries, Hungary, Poland and other central European countries. Thus, in the late 1990s, a greater than three-fold difference in kidney cancer mortality was observed between the highest rates in the Czech Republic, the Baltic Republics and Hungary, and the lowest ones in Romania, Portugal and Greece. Tobacco smoking is the best recognised risk factor for kidney cancer, and the recent trends in men, mainly in western Europe, can be related to a reduced prevalence of smoking among men. Tobacco, however, cannot account for the recent trends registered in wome

Attosecond screening dynamics mediated by electron-localization

Transition metals with their densely confined and strongly coupled valence electrons are key constituents of many materials with unconventional properties, such as high-Tc superconductors, Mott insulators and transition-metal dichalcogenides. Strong electron interaction offers a fast and efficient lever to manipulate their properties with light, creating promising potential for next-generation electronics. However, the underlying dynamics is a fast and intricate interplay of polarization and screening effects, which is poorly understood. It is hidden below the femtosecond timescale of electronic thermalization, which follows the light-induced excitation. Here, we investigate the many-body electron dynamics in transition metals before thermalization sets in. We combine the sensitivity of intra-shell transitions to screening effects with attosecond time resolution to uncover the interplay of photo-absorption and screening. First-principles time-dependent calculations allow us to assign our experimental observations to ultrafast electronic localization on d-orbitals. The latter modifies the whole electronic structure as well as the collective dynamic response of the system on a timescale much faster than the light-field cycle. Our results demonstrate a possibility for steering the electronic properties of solids prior to electron thermalization, suggesting that the ultimate speed of electronic phase transitions is limited only by the duration of the controlling laser pulse. Furthermore, external control of the local electronic density serves as a fine tool for testing state-of-the art models of electron-electron interactions. We anticipate our study to facilitate further investigations of electronic phase transitions, laser-metal interactions and photo-absorption in correlated electron systems on its natural timescale