41 research outputs found

    Comparison of cohesive powder flowability measured by Schulze Shear Cell, Raining Bed Method, Sevilla Powder Tester and new Ball Indentation Method

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    Poor powder flow leads to many problems during manufacturing and can lead to inaccurate dosing and off-specification products. Powder flowability is commonly assessed under relatively high applied loads using shear cells by characterising the unconfined yield strength at a range of applied loads. For applied stresses below 1 kPa, it becomes increasingly difficult to obtain reliable values of the unconfined yield strength. The bulk cohesion and tensile strength of the powder are then obtained by extrapolating the yield locus to zero and negative loads, respectively. However, the reliability of this approximation for a given material is not known. To overcome this limitation, techniques such as the Raining Bed Method, Sevilla Powder Tester and the newly-developed Ball Indentation Method may be used. In this paper, we report our measurement results of the tensile strength of glass beads, α-lactose monohydrate and various sizes of fluid catalytic cracking powders determined by the Sevilla Powder Tester and Raining Bed Method and compare them with those inferred from the Schulze Shear Cell. The results of the latter are also compared with those of the Ball Indentation Method. The outcome suggests that in the case of shear cell tests, the extrapolation of the yield locus to lower or negative loads is unsafe. The ball indentation method enables the characterisation of highly cohesive powders at very low compressive loads; however extrapolation to negative loads is still not reliable. In contrast, the Sevilla Powder Tester and Raining Bed Methods are able to characterise the tensile strength directly, but high bulk cohesion poses difficulties as the internal bed failure needs to be analysed in order to reliably estimate the tensile strength. These methods provide a better understanding of powder flow behaviour at low stresses, thus enabling a greater control of manufacturing processes

    The theory of brain-sign: a physical alternative to consciousness

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    Consciousness and the mind are prescientific concepts that begin with Greek theorizing. They suppose human rationality and reasoning placed in the human head by (in Christian terms) God, who structured the universe he created with the same kind of underlying characteristics. Descartes' development of the model included scientific objectivity by placing the mind outside the physical universe. In its failure under evidential scrutiny and without physical explanation, this model is destined for terminal decline. Instead, a genuine biological and physical function for the brain phenomenon can be developed. This is the theory of brain-sign. It accepts the causality of the brain as its physical characteristics, already under scientific scrutiny. What is needed is a new neurophysiological mapping language that specifies the relation of the structure and operation of the brain to organismic action in the world. Still what is lacking is an account of how neurophysiologies in different organisms communicate on dynamic, i.e. unpredictable, tasks. It is this evolved capacity that has emerged as brain-sign. Thus rather than mentality being an inner epistemological parallel world suddenly appearing in the head, brain-sign, as the neural sign of the causal status of the brain, facilitates the communicative medium of otherwise isolated organisms. The biogenesis of the phenomenon emerges directly from the account of the physical brain, and functions as a monistic feature of organisms in the physical world. This new paradigm offers disciplinary compatibility, and genuine development in behavioral and brain sciences

    ICTs connecting global citizens, global dialogue and global governance. A call for needful designs

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    Humankind is on the transition to a supra-system of humanity, according to which social relationships – that organise the common good – are re-organised such that global challenges are kept below the threshold of a self-inflicted breakdown. In order to succeed, three conditions are imperative: (1) Global governance needs a global conscience that orients towards the protection of the common good. (2) Such global governance needs a global dialogue on the state of the common good and the ways to proceed. (3) Such a global dialogue needs global citizens able to reflect upon the current state of the common good and the ways to proceed to desired states. Each of these imperatives is about a space of possibilities. Each space nests the following one such that they altogether form the scaffolding along which institutions can emerge that realise the imperatives when proper nuclei are introduced in those spaces. Such nuclei would already support each other. However, the clue is to further their integration by Information and Communication Technologies. An information platform shall be launched that could cover any task on any of the three levels, entangled with the articulation of cooperative action from the local to the global, based on the cybersubsidiarity model. This model is devised to ensure the percolation of meaningful information throughout the different organisational levels.2019-2

    Reliability Analysis in Geotechnics with Finite Elements - Comparison of Probabilistic, Stochastic and Fuzzy Set Methods

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    The finite element method is widely used for solving various problems in geotechnical engineering practice. The input parameters required for the calculations are generally imprecise. The paper is devoted to a comparison of probabilistic, stochastic and fuzzy set method for reliability analysis with respect to its applicability for practical problems in geotechnical engineering
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