Methodological aspects around the reconstruction of surname sub-sets in bimodal networks

This article addresses the methodological aspects surrounding the transformation of a cadastral land registry from the end of the 19th century belonging to the department of Humahuacua, Jujuy province (Argentina), in a series of bimodal matrices and networks. The idea that has guided the relational treatment of the data towards said historical sources, starts from the premise that certain individuals carrying a discrete set of surnames, and who have shared similar monetary amounts of appraisal declared in the said land cadastre, were more likely to link with each other in different areas of social life, such as the limited political and regional power circle of the late nineteenth century in Jujuy. The results obtained show the possibility of delimiting and reconstructing sub-sets of surnames that are linked less and/or more frequently to each other, according to four pre-constructed appraisal categories based on a segmentation of the registered monetary valuations in the land registry. Likewise, and as a product of this new grouping of information arising from the application of Social Network Analysis (ARS), it is feasible to limit the study to the qualitative aspects (age, residence, descent, nuptial ties, baptismal sponsorships) of individuals that formed part of these resulting sub-sets, through the focused search of ecclesiastical acts recorded within the same historical period.

Bimodality and Increased Amount of Crosslinker Enhances Tensile Properties of the Silicone Networks

The effect of bimodality i.e. blending short and long chain (0 to 80 % w/w) silicone prepolymers, and that of concentration of the crosslinker on the tensile properties such as percent elongation at break (%Eb), ultimate tensile strength (UTS), 100 % modulus and elastic modulus (E) has been investigated. It was found out that the greater amount of crosslinker used for crosslinking provide an additional reinforcement to the silicone network whereas bimodality further significantly accentuates this effect. Remarkably, the %Eb of the silicone networks was found to increase to an average of 2.4 times than that of the monomodal network, cured in each of the three series of bimodal networks cured with 3.9, 9.1 and 12.3% of crosslinker. The optimum property in each case was observed at about 70 mol % of P100. The over all order of sensitivity of these properties up to about 70 mol % of short chain prepolymer has been observed to be as: %Eb > UTS > 100% modulus > elastic modulus. It has been shown that in addition to the previously published reports the tensile properties are acutely dependent not only upon the degree of crosslinking and primary molecular weight; but also on bimodality and crosslinker concentration for preparation of the unfilled silicone polymer networks. The concept of phase inversion (or phase transition) associated with the optimum properties in polymer blends has for the first time been applied to the bimodal polymer networks. It has been observed that the maxima in tensile properties generally corresponds to phase inversion which takes place at 0.5 volume fraction (70 mol %) of short chain (P100) prepolymer which is in accordance with the literature for other systems.