Investigation of the influence of the zeta-potential on the filtration rate in the presence of collectors

The value of the zeta-potential does not have an explicit effect, which is expressed by a simple math correlation, on filtration rate when a solution of the tested collector is filtered through a cake prepared under standard conditions from the examined particulate material. The zeta-potential measurements and filtration tests were carried out on silica and galena with solutions contg. a cationic container ANP and Et xanthane, resp. at PH = 6.5, varying concentration of the agent (0-2500 g/ton), and under a vacuum of 100 to 600 mm Hg

Cathodoluminescence of Recent biogenic carbonates: environmental and ontogenetic fingerprint

Cathodoluminescence (CL) examination of Recent biogenic carbonates shows that they are often luminescent regardless of their mineralogical composition (calcite v. aragonite), habitat (marine v. fresh water), way of life (sessile v. vagile) or environment (hyper- v. hyposaline water). Thus, the presence of luminescence in biogenic particles is not a reliable indicator of diagenetic alteration as some authors have suggested. In addition, CL can reveal variations in the mineralogy of shell material (e.g. regenerated calcitic v. primary aragonitic) and can highlight growth-related structures. Manganese (Mn2+) is the most likely activator of this luminescence, and its content in the shells of benthic organisms seems to be linked to growth rate, ontogeny, open sea conditions, bathymetry and salinity. In neritic environments the Mn2+ content and the CL of molluscs and foraminifera appear to increase with decreasing salinity. This study indicates that CL may be an important tool for the determination of environmental and ontogenetic parameters in biogenic carbonates in addition to its current use indiagenetic studie

Effect of the anisotropy of monocrystalline silicon mechanical properties on the dynamic characteristics of a micromechanical gyroscope

The aim of the research was to determine the effect of temperature on mechanical properties of a micromechanical gyroscope with the sensing element mounted on a silicon wafer, with the crystallographic orientation of (100) (110) (111). The research is of current relevancy since the metrological characteristics that depend on the eigenfrequencies over the full temperature range are to be controlled. The temperature-modal analysis of the micromechanical gyroscope model was performed with ANSYS program. The temperature dependence for eigenfrequencies was obtained. The dependence of the scale factor on temperature for the most temperature-independent variant of sensor positioning on the wafer was determined. The developed mathematical model was used to find the forms of the output oscillations of the gyroscope

Addressing the Symbol Grounding Problem with Constraints in Neuro-Symbolic Planning

In this paper, we address the Symbol Grounding Problem (SGP) in the context of neuro-symbolic planning, where the categorical vectors learned to represent high dimensional inputs suffer from instability, which poses a problem of efficiency during the planning phase. One way to alleviate the SGP is to enforce constraints — among the latent variables — by expressing them in the loss function during the learning process. Combining an existing tool for invariant search and ideas from Logic Tensor Networks (fuzzy logic), we propose to automatize the process of finding and enforcing relevant constraints. We apply our idea to LatPlan, a domain independent, image-based classical planner

1867, l’année de tous les Rapports. Les lettres et les sciences à la fin du Second Empire

En juillet 1865, le ministre de l’Instruction publique Victor Duruy propose, au Conseil des ministres, « de faire l’histoire des progrès de toutes les sciences depuis vingt ans », dans le cadre de la préparation de l’Exposition universelle de 1867. Vers la fin octobre, il adresse à Napoléon III un rapport dans lequel il demande à l’empereur d’« autoriser le ministère de l’Instruction publique à être exposant » lors de la prochaine Exposition universelle à Paris. Une fois ce rapport approuvé par Napoléon III, il informe, en décembre, le commissaire général de la future Exposition universelle, le conseiller d’État Frédéric Le Play, que son ministère déposera une série de Rapports « sur les principales œuvres produites par l’esprit français ». De cette initiative sortiront 29 Rapports, plus ou moins importants en volume, écrits par des auteurs plus ou moins connus aujourd’hui. Ce corpus considérable a été sorti de l’oubli et étudié pendant trois ans par un groupe interdisciplinaire composé d’une quinzaine de chercheurs (historiens, historiens des sciences, de la philosophie et de la littérature). Il fournit un excellent état des préoccupations concernant les sciences et les lettres à la veille de la guerre de 1870. Les résultats de l’enquête permettent au lecteur d’aujourd’hui d’évaluer le patrimoine d’un XIXe siècle dont nous sommes les héritiers, aussi bien en ce qui concerne les conceptions relatives aux lettres, aux sciences et aux techniques, que pour les relations entre la recherche, l’université et la société

PIT telemetry as a method to study the habitat requirements of fish populations: application to native and stocked trout movements

Passive integrated transponder (PIT) technology was used to study the behaviour of fishes during the summer season in two headwater streams of northeastern Portugal. A total of 71 PIT tags (12 mm long x 2.1 mm diameter) were surgically implanted in 1+ stocked (39) and native (32) brown trout of two size classes (< 20.0 and ≥ 20.0 cm). Eight independent antennae, connected to a multi-point decoder (MPD reader) unit, were placed in different microhabitats, selected randomly every three days during the observation period (29 August to 9 September in Baceiro stream and 19 September to 4 October in Sabor stream). The results confirmed this method as a suitable labour efficient tool to assess the movement and habitat use of sympatric stocked and native trout populations. About 76.9% of stocked and 59.4% of native PIT tagged trouts were detected. Multivariate techniques (CCA, DFA and classification tree) showed a separation in habitat use between the two sympatric populations. Stocked trout mainly used the microhabitats located in the middle of the channel with higher depths and without cover. Furthermore, these fishes displayed a greater mobility and a diel activity pattern different to native trout populations

The emergence of meaningful geometry

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Impact of volatile phenols and their precursors on wine quality and control measures of Brettanomyces/Dekkera yeasts

Volatile phenols are aromatic compounds and one of the key molecules responsible for olfactory defects in wine. The yeast genus Brettanomyces is the only major microorganism that has the ability to covert hydroxycinnamic acids into important levels of these compounds, especially 4-ethylphenol and 4-ethylguaiacol, in red wine. When 4-ethylphenols reach concentrations greater than the sensory threshold, all wine’s organoleptic characteristics might be influenced or damaged. The aim of this literature review is to provide a better understanding of the physicochemical, biochemical, and metabolic factors that are related to the levels of p-coumaric acid and volatile phenols in wine. Then, this work summarizes the different methods used for controlling the presence of Brettanomyces in wine and the production of ethylphenols