Investigation into the effects of magnetic agitation and pulsed current on the development of Sn Cu alloy electrodeposits

SnCu alloy electrodeposits have found a wide range of applications in the electronics, automotive and aerospace industries. In the current research, the electrodeposition of SnCu alloy coatings produced from an electrolyte based on fluoroboric acids was thoroughly studied. The cathode current density was found to have a significant impact on the appearance and the surface morphology of SnCu alloy electrodeposits. Our experimental results suggested that deposition current density, magnetic agitation and pulsed current parameters (pulse frequency and duty cycle) were all found to be crucial factors significantly affecting the chemical composition of the SnCu alloy electrodeposits. In addition, the employment of pulsed current techniques significantly improved the edge effect and the surface roughness. Whisker growth on the SnCu alloy electrodeposits was assessed. All the samples subjected to different electroplating condition were prone to develop Sn whiskers after a few weeks of storage at room temperature.<br/

Codes and coding: Sebeok’s zoosemiotics and the dismantling of the fixed-code fallacy

The concept of code has a long and varied history across the sciences, the social sciences and the humanities. In the interdisciplinary field of biosemiotics it has been foundational through the idea of code duality (Hoffmeyer and Emmeche 1991); yet it has not been free from controversy and questions of definition (see, for example, Barbieri 2010). One reason why code has been so central to modern semiotics is not simply a matter of the linguistic heritage of semiology and the work of Jakobson who straddled both semiology and semiotics. Rather, it has been the programmatic reconceptualization of code which is woven through the work of modern semiotics’ founder, the father of both biosemiotics and zoosemiotics, Thomas A. Sebeok. A biologist manqué, a communication theorist influenced by cybernetics and a semiotician deriving from the ‘major tradition’ of Peirce, arguably Sebeok’s most systematic considerations of code were offered in his essays on zoosemiotics, largely from his 1963 coining of the term onwards. This article principally revisits the 1972 collection of Sebeok’s zoosemiotic essays and suggests that his particular observations in respect of analogue and digital codes and their relation to evolution in the world of animals harbours an opportunity to rethink and potentially resolve, through an ethological lens, current controversies regarding the status of code

Exercise redox biochemistry:conceptual, methodological and technical recommendations

Exercise redox biochemistry is of considerable interest owing to its translational value in health and disease. However, unaddressed conceptual, methodological and technical issues complicate attempts to unravel how exercise alters redox homeostasis in health and disease. Conceptual issues relate to misunderstandings that arise when the chemical heterogeneity of redox biology is disregarded which often complicate attempts to use redox-active compounds and assess redox signalling. Further, that oxidised macromolecule adduct levels reflect formation and repair is seldom considered. Methodological and technical issues relate to the use of out-dated assays and/or inappropriate sample preparation techniques that confound biochemical redox analysis. After considering each of the aforementioned issues, we outline how each issue can be resolved and provide a unifying set of recommendations. We specifically recommend that investigators: consider chemical heterogeneity, use redox-active compounds judiciously, abandon flawed assays, carefully prepare samples and assay buffers, consider repair/metabolism, use multiple biomarkers to assess oxidative damage and redox signalling

The Current Crowding Effect in ZnO Nanowires with a Metal Contact

Nanoscale electron tunneling and thermionic transport via the metal-semiconductor interface of ZnO nanowires is found to be strongly affected by the metal contact shape, the metal-semiconductor interface radius and the nanowire radius. Our full 3D simulations show that the current crowding effect occurs for end-bonded contacts due to the geometry variation in the case of Schottky Au-ZnO nanowire interfaces. The change in the geometry will also lead to a change in the electrical behavior of the contact from Schottky to Ohmic which can substantially reduce the contact resistance

Sign, object, thing: an eternal golden braid

This review argues that The Human Use of Signs (Deely, 1994) is both pivotal and exceptional in the oeuvre of John Deely. It argues that the volume is exceptional because of its unusual explicatory structure and that it is pivotal because of its extended focus on issues arising from the distinction of ‘sign’, ‘object’, and ‘thing’. Among these issues are the idea of the postmodern, objectivity, relation, and the semiotic animal