Design Criteria of Uniflow Cyclones for the Separation of Solid Particles from Gases

The main advantages of uniflow cyclones compared to standard reverse flow cyclones are their compact design and their capability of being easily integrated into pipelines. Experiments show that a 0.2m-diameter horizontal uniflow cyclone re-moves 88.6% of 2 g/m3 of fine mineral powder (d10=3m, d50=20m) from 1000 m3/h air at a pressure loss of 2510 Pa (0.364 psi)

Recoil experiments determine the eigenmodes of viscoelastic fluids

We experimentally investigate the recoil dynamics of a colloidal probe particle after shearing it with constant velocity through a viscoelastic fluid. The recoil displays two distinct timescales which are in excellent agreement with a microscopic model built on a particle being linked to two bath particles by harmonic springs. This model yields analytical expressions which reproduce all experimental protocols, including additional waiting periods before particle release. Notably, two sets of timescales appear, corresponding to reciprocal and nonreciprocal eigenmodes of the model.Comment: 5 pages, 4 figure

Bartter- and Gitelman-like syndromes: salt-losing tubulopathies with loop or DCT defects

Salt-losing tubulopathies with secondary hyperaldosteronism (SLT) comprise a set of well-defined inherited tubular disorders. Two segments along the distal nephron are primarily involved in the pathogenesis of SLTs: the thick ascending limb of Henle’s loop, and the distal convoluted tubule (DCT). The functions of these pre- and postmacula densa segments are quite distinct, and this has a major impact on the clinical presentation of loop and DCT disorders – the Bartter- and Gitelman-like syndromes. Defects in the water-impermeable thick ascending limb, with its greater salt reabsorption capacity, lead to major salt and water losses similar to the effect of loop diuretics. In contrast, defects in the DCT, with its minor capacity of salt reabsorption and its crucial role in fine-tuning of urinary calcium and magnesium excretion, provoke more chronic solute imbalances similar to the effects of chronic treatment with thiazides. The most severe disorder is a combination of a loop and DCT disorder similar to the enhanced diuretic effect of a co-medication of loop diuretics with thiazides. Besides salt and water supplementation, prostaglandin E2-synthase inhibition is the most effective therapeutic option in polyuric loop disorders (e.g., pure furosemide and mixed furosemide–amiloride type), especially in preterm infants with severe volume depletion. In DCT disorders (e.g., pure thiazide and mixed thiazide–furosemide type), renin–angiotensin–aldosterone system (RAAS) blockers might be indicated after salt, potassium, and magnesium supplementation are deemed insufficient. It appears that in most patients with SLT, a combination of solute supplementation with some drug treatment (e.g., indomethacin) is needed for a lifetime

AUTOMATED HIGH RESOLUTION MEASUREMENT OF HELIOSTAT SLOPE ERRORS

A new optical measurement method that simplifies and optimizes the mounting and canting of heliostats and helps to assure their optical quality before commissioning of the solar field was developed. This method is based on the reflection of regular patterns in the mirror surface and their distortions due to mirror surface errors. The measurement has a resolution of about one million points per heliostat with a measurement uncertainty of less than 0.2 mrad and a measurement time of about one minute per heliostat. The system is completely automated and allows the automatic measurement of an entire heliostat field during one night. It was extensively tested at the CESA-1 heliostat field at the Plataforma Solar de Almería. Comparisons of flux simulations based on the measurement results with real flux density measurements were performed. They showed an excellent agreement and demonstrated in a striking manner the high measurement accuracy and high grade of detail in the simulation achieved by this technique

Les conceptions de la république en Europe Centrale au XVIIIe siècle

Helmut Reinhalter, The conceptions of the Republic in Central Europe in the 18th century. In Germany, the Republic became a central concept in the philosophic debate after the French and American revolutions. According to Kant, this concept is found in all political regimes where the power is premised on the general will of the sovereign people and where the citizens submit to juridical laws. It is therefore an eternal norm for all constitutions. In Germany, several conceptualisations of this abstraction take shape, including constitutional monarchy. With the exception of the Jacobins of the left bank of the Rhine, few of the authors had spread the idea that the example of the democratic republic of France in the Year II was the only legitimate model.Helmut Reinalter, Le concezioni della Repubblica in Europa Centrale nel Settecento. In Germania, la Repubblica diventò un concetto centrale nel dibattito filosofico dalle rivoluzioni americana e francese. In Kant, questo concetto si applica ad ogni regime politico in cui il potere è costruito dalla volontà generale del popolo sovrano, in cui anche i cittadini sono sottomessi a leggi giuridiche. È dunque una norma eterna per ogni costituzione. Ci furono in Germania parecchie concezioni della realizzazione di questo concetto, compresa la monarchia costituzionale. Pochi autori, tranne i giacobini della riva sinistra del Reno, hanno propagato l’idea che la repubblica democratica, il cui esempio era dato dalla Francia dell’anno II, fosse l’unica legittima.En Allemagne, la République devint un concept central dans le débat philosophique à partir des révolutions américaine et française. Chez Kant, ce concept recouvre tout régime politique où le pouvoir est construit sur la volonté générale du peuple souverain, où les citoyens sont soumis à des lois juridiques. Il est donc une norme éternelle pour toute constitution. Il y eut en Allemagne plusieurs conceptions de la concrétisation de ce concept, y compris la monarchie constitutionnelle. En dehors des jacobins de la rive gauche du Rhin, peu d’auteurs ont propagé l’idée que la république démocratique dont la France de l’an II donnait l’exemple, était la seule légitime.Reinalter Helmut. Les conceptions de la république en Europe Centrale au XVIIIe siècle. In: Annales historiques de la Révolution française, n°296, 1994. pp. 223-233

Biodiversität am Piz Alv (2974 m): Lokaler hot spot in der Region Bernina (Graubünden, Schweiz)

During the years 2002, 2003 and 2006, vegetation records, 201 in total covering 30 plant communities with a total of 415 vascular plants, were kept about an area of 0.32 km2 at the foot of the Piz Alv (2974 m a.s.l., Bernina pass, Canton of the Grisons, Switzerland). The records have been investigated regarding biodiversity (Shannon-index and evenness) and the constancy of occurrence. In addition an earlier vegetation map of Piz Alv has been revised and completed. On the lower mountain slope the dominating features are acidophilic subalpine meadows (Geo montani-Nardetum), slope peat bogs and pastures, whereas on the upper slope section, basophilic alpine meadows (Seslerio-Caricetum sempervirentis) and pioneer plant communities (Dryadetum octopetalae) prevail. The highest biodiversity is shown by the plant communities Geo montani-Nardetum and Seslerio-Caricetum sempervirentis with 179 and 152 plant species respectively (Shannonindex 2.80 and 2.37 respectively). The highest constancy of plant species occurrence is exhibited by the basophilic alpine meadows (Seslerio-Caricetum sempervirentis), subalpine pastures (Poion alpinae), hanging bogs and alluvions. 10 species of orchids could be recorded and more than 12 additional rare plant species, found in the Swiss Red Data Book, could be recognized. The investigated locality in the Bernina pass area represents a local Swiss hot spot of plant biodiversity and should be put under nature protection

Automated High Resolution Measurement of Heliostat Slope Errors

A new optical measurement method that simplifies and optimizes the mounting and canting of heliostats and helps to assure their optical quality before commissioning of the solar field was developed. This method is based on the reflection of regular patterns in the mirror surface and their distortions due to mirror surface errors. The measurement has a resolution of about one million points per heliostat with a measurement uncertainty of less than 0.2 mrad and a measurement time of about one minute per heliostat. The system is completely automated and allows the automatic measurement of an entire heliostat field during one night. It was extensively tested at the CESA-1 heliostat field at the Plataforma Solar de Almería. Comparisons of flux simulations based on the measurement results with real flux density measurements were performed. They showed an excellent agreement and demonstrated in a striking manner the high measurement accuracy and high grade of detail in the simulation achieved by this technique