Study of springback of green bodies using micromechanical experiments and the discrete element method

The Discrete Element Method (DEM) is today a commonly used tool to simulate compaction of particulate media. The main issue when using DEM in compaction problems is the description of the contact between two powder particles. If the material properties are known, analytical and semi-analytical methods can be used [1,2] but for many industrial applications, for instance spray dried granules, the mechanical behaviour is unknown. The compaction behaviour and green properties of a cemented carbide powder is studied in this work and the issue of the contact description is solved by performing experiments on the powder granules. Firstly, compression tests are made on the single granules giving information of the mechanical properties at low strains. To get information at high strains, which are needed in powder compaction simulations, nanoindentation tests are performed. The measured material parameters are used in a FE model of two spheres in contact and the resulting contact law is exported to a DEM program. The DEM program is used to investigate the compaction properties of a powder compact and especially the springback during unloading which is important for predicting the final shape of the product. The results are compared with presently performed experiments and the applicability range of the discrete element simulations will be discussed

Tobacco smoking increases dramatically air concentrations of endotoxin.

We used a mass spectrometry-based assay for identifying the endotoxin (lipopolysaccharide, LPS) marker (R)-3-hydroxytetradecanoic acid in cigarette smoke particles and found that smoking involved inhalation of 17.4 pmol of endotoxin per each smoked cigarette. Indoor exposure to environmental tobacco smoke (ETS) entailed inhalation of 12.1 pmol of LPS/m3 air, an amount that was 120 times higher than the levels found in smoke-free indoor air. Endotoxin is one of the most potent inflammatory agents known, hence our results may help to explain the high prevalence of respiratory disorders among smokers, and they may also draw attention to a hitherto unknown or neglected risk factor of ETS

Impact of temperature on growth and metabolic efficiency of Penicillium roqueforti - Correlations between produced heat, ergosterol content and biomass

The influence of temperature on the growth of the mould Penicillium roqueforti growing on malt extract agar was studied by correlating the produced heat (measured by isothermal calorimetry), ergosterol content (quantified by GC-MS/MS) and biomass of the mould at 10, 15, 20, 25 and 30°C. The results were analysed with a simple metabolic model from which the metabolic efficiency was calculated. The results show that the impact of temperature on growth rate and metabolic efficiency are different: although the mould fungus had the highest growth rate (in terms of thermal power, which was continuously measured) at 25°C, the substrate carbon conversion efficiency (biomass production divided by substrate consumption, both counted as moles carbon) was highest at 20°C. The temperature of the most rapid growth did therefore not equal the temperature of the most efficient growth

Varför förändras (inte) ordböcker? Exemplet Florinus

Why do/don’t dictionaries change? The Florinus example. This article discusses changesoccurring in a minor thematic dictionary, compiled by the Finnish priest Henrik Florinus andfirst published in 1678 in Turku under the title Nomenclatura Rerum brevissima Latino-Sveco-Finnonica. In the following hundred years, this dictionary was reissued in at least fifteen editions,the last in 1771 in Stockholm under the title Vocabularium Latino-Svecum. The article identifiesand discusses the different reasons for the changes (modernisation, product development, spacerequirements, mistakes, supply of printing types, and modifications marking a new edition) aswell as for the absence of certain changes (labour savings, the circumstance that this type ofdictionary no longer was viewed as modern, and the authoritativeness of dictionaries)

En ”mer l. mindre stor” stor ordbok – om variationerna i SAOB:s omfång och ambitionsnivå

The first section of The Swedish Academy Dictionary (SAOB), describing the Swedish language from 1521 to the present, was published already in 1893. When the dictionary is finished in a few years, it will comprise thirty-eight volumes. During this span of over 120 years, its level of ambition (and accordingly, its scope) has varied considerably. As shown in the paper, four periods can be distinguished: two periods (until c. 1920 and c. 1960–2002) when the ambition was to account for virtually all words and uses of words that were documented, and two periods (c. 1920–1960 and c. 2002 onwards) when quite strict rules of restriction steered the work. After summing up these rules, the paper gives examples of how the varying levels of ambition are reflected both in the selection of lemmas and in the (more or less exhaustive) way they are addressed

Vilket språk var utgångspunkten? Om ursprunget till den svenska vokabulären i en fyrspråkig ordbok utgiven i Riga 1705

In the year 1705, a German-Swedish-Polish-Lettish dictionary entitled Wörter-Büchlein,wie etzliche gebräuchliche Sachen auff Teutsch, Schwedisch, Polnisch undLettisch, zu benennen seynd was published in Riga. The dictionary was a revision ofVocabularium wie etzliche gebräuchliche Sachen auff Teutsch, Lateinisch, Polnischund Lettisch, aussprechen seynd, a dictionary also encompassing four languages,also published in Riga but in 1688. As can be seen from the titles, Swedish in thenewer dictionary replaced the Latin in the older book. This article explores thequestion of which language in the older dictionary was used a basis for thepresentation of the Swedish vocabulary. A comparision between the differentlanguages shows that even though German was predominantly used, this was nottrue for all of the articles. In several examples, the author of the section concerningthe Swedish vocabulary obviously used Latin instead as a basis

Uncoupled and coupled approaches to predict macrocrack initiation in fiber reinforced ceramic matrix composites

International audienceLocalized fiber pull-out is one of the fracture features of fiber reinforced ceramic matrix composites. The onset of this mechanism is predicted by using Continuum Damage Mechanics, and corresponds to a localization of the deformations. After deriving two damage models from a uni-axial bundle approach, and criteria at localization, different axisymmetric configurations are analyzed through two different approaches to predict macrocrack initiation

Endotoxin markers in bronchoalveolar lavage fluid of patients with interstitial lung diseases

Background: Exposure to inhaled endotoxins (lipopolysaccharides, LPS) of Gram-negative bacteria commonly found in indoor environments and assessed in secondary tobacco smoke, has been associated with airway inflammation and asthma exacerbation. The bronchoalveolar lavage fluid (BALf) from patients with interstitial lung diseases (sarcoidosis, lung fibrosis, smoking-related ILD, eosinophilic disorders) was analyzed for the markers of lipopolysaccharide (LPS, endotoxin). Methods: BALf was obtained from patients with diffuse lung diseases: idiopathic pulmonary fibrosis (n = 42), sarcoidosis (n = 22), smoking-related-ILD (n = 11) and eosinophilic disorders (n = 8). Total cell count and differential cell count were performed. In addition, samples were analyzed for 3-hydroxy fatty acids (3-OHFAs) of 10-18 carbon chain lengths, as markers of LPS, by gas chromatography-tandem mass spectrometry. Results: The highest LPS concentration was found in patients with eosinophilic disorders and the lowest in patients with sarcoidosis (p 25%) and those with lower proportion was also significant (p = 0.014). A significant correlation was found between LPS and eosinophils, but not between LPS and lymphocytes, neutrophils, or macrophages count. Conclusions: A positive relationship of LPS and eosinophilic pulmonary disorders may be linked to a persistent eosinophil activation mediated by Th2 pathway: chronic endotoxin exposure would intensify Th2 pathway resulting in fibrosis and, at the same time, eosinophil stimulation, and hence in eosinophilic pulmonary disorders