When it was first released in 1962, The Shape of Time presented a radically new approach to the study of art history. Categories of science from more exoteric to esoteric, more concrete to more flexible:Ī) Popular science: attractive, lively, readable, artificially simplified science in which facts are reality and truth is objectiveī) Vademecum science: a closed, organized system of the "commonly held" view of science where facts become fixedĬ) Journal science: a personal, cautious and modest system open to contradictions and explorations Within a thought collective, there is a hierarchy consisting of two different groups:Ī) Esoteric: a small group of experts with specialized knowledge who develop exoteric, popular knowledgeī) Exoteric: a larger, more "popular" group that creates public opinion, though not the entire public It changes as collectives gradually change with the incorporation/adaptation or rejection of challenges to the thought style. Truth is only true within a single collective. Facts are 1) in line with the interests of the collective, 2) accepted by the general membership of the collective, and 3) expressed in the style of the collective. A scientific fact is a signal of resistance opposing free, arbitrary thinking. In this, he/she is influenced by the "thought style," an ambiguous cloud which directs perception and limits the options for interpretation without the perceiver being aware that they are being influenced. The individual's role is to decide whether results fit within the conditions specified by the collective. The thought collective is a community of persons mutually exchanging ideas it is the bearer of collective knowledge and the historical developer of knowledge. The social structure involved in cognition is conceived as the relationship between:Ģ) the object to be known (objective reality)ģ) the existing fund of knowledge (provided by the thought collective). All ideas stem from "proto-ideas" - hazy, unspecific, unscientific concepts accepted as truth in their time period and existing in a socio-cognitive system. Additionally, combination of spacer surface roughness and solute molecular sizes were found to be the significant factors in cake-buildup on the spacer and the membrane.Fleck focuses on the cognitive and social structures idea and fact development and acceptance. The flow hydrodynamics induced by the spacer geometry influenced the re-suspension rate of the deposited particles in the filtration cake.
The TCLP spacer is able to operate at the intermediate pore blocking mechanism at higher fluxes compared to the net-type spacer for both solutes tested. The results demonstrated that spacer design has a significant effect on the fouling mechanism in UF separation. A difference in spacer performance was observed when the solute was changed from SA to dextran.
Experimental data were fitted using the filtration model and the results were evaluated in terms of cake filtration constant (K c, m −1), rate of cake erosion (S, kg.m −2.s −1), particle resuspension rate (B, s −1), and specific cake resistance (α, m.kg −1), in order to understand the cake formation and erosionbehavior that is influenced by the spacer geometry. Flux-stepping tests were performed to determine the threshold flux (TF) in each case. Filtration resultsofthree different spacer geometries, which included two 3D-printed spacers based on triply periodic minimal surfaces (TPMS) (Gyroid and TCLP) and one commercial net-type spacer, were analyzed. Thecombined intermediate pore blocking and cake filtration model was employed,coupled with experimental crossflow UF experiments of dextran and sodium alginate (SA) in aqueous feed solutions. The impact of feed spacer design on membrane fouling mechanism in ultrafiltration (UF) process under constant flux mode was systematically investigated.
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