Polymeric surfactants at liquid–liquid interfaces: Dependence of structural and thermodynamic properties on copolymer architecture

Polymeric surfactants are amphiphilic molecules with two or more different types of monomers. If one type of monomer interacts favorably with a liquid, and another type of monomer interacts favorably with another, immiscible liquid, then polymeric surfactants adsorb at the interface between the two liquids and reduce the interfacial tension. The effects of polymer architecture on the structural and thermodynamic properties of the liquid–liquid interface are studied using molecular simulations. The interface is modeled with a non-additive binary Lennard-Jones fluid in the two-phase region of the phase diagram. Block and gradient copolymer surfactants are represented with coarse-grained, bead-spring models, where each component of the polymer favors one or the other liquid. Gradient copolymers have a greater concentration at the interface than do block copolymers because the gradient copolymers adopt conformations partially aligned with the interface. The interfacial tension is determined as a function of the surface excess of polymeric surfactant. Gradient copolymers are more potent surfactants than block copolymers because the gradient copolymers cross the dividing surface multiple times, effectively acting as multiple individual surfactants. For a given surface excess, the interfacial tension decreases monotonically when changing from a block to a gradient architecture. The coarse-grained simulations are complemented by all-atom simulations of acrylic-acid/styrene copolymers at the chloroform-water interface, which have been studied in experiments. The agreement between the simulations (both coarse-grained and atomistic) and experiments is shown to be excellent, and the molecular-scale structures identified in the simulations help explain the variation of surfactancy with copolymer architecture

Aphrati and Kato Syme: Pottery, Continuity, and Cult in Late Archaic and Classical Crete

The analysis of ceramics from Aphrati sheds valuable new light on the history of this Cretan settlement and on its relationship with a nearby rural sanctuary at Kato Syme in the Late Archaic and Classical periods. It has long been held that Aphrati was deserted from ca. 600 to 400 B.C. A pottery deposit from the domestic quarter, however, now supports occupation of the city during this period. A ceramic classification system is presented and the morphological development and absolute chronology of several key shapes at Aphrati and Kato Syme are plotted. Historical implications of the ceramic evidence are also explored

Theory and (in) Practice: The Problem of Integration in Art and Design Education

© 2014 NSEAD/John Wiley Sons Ltd. This paper examines the relationship between art 'theory' and art 'practice' in British art education at post-compulsory level, with a focus on the ways in which theory is framed and delivered and what this means for its integration. Drawing upon constructions of knowledge and approaches to integration as a technique and integration as a philosophy, suggestions are made on ways of organising theory in relation to studio practice. Theory is discussed here in terms of its common label in British Further and Higher Education: Critical and Contextual Studies (CCS), and particular reference is made to data drawn from research into practices of CCS on the BTEC Extended Diploma in Art and Design in 2008-10. Through the data, three dominant models of CCS are proposed and examined in order to identify the problem of integration and to make suggestions on what it means to integrate CCS in an art and design course

Veedors, marquejadors, maestros : el valor de la experiencia en la carpintería medieval. El ejemplo valenciano

En la carpintería medieval valenciana, la experiencia y la destreza eran dos nociones complementarias de la idea más amplia de pericia. La apreciación de este valor añadido hacía del experto una fi gura imprescindible en la corporación de ofi cios, a través de los diversos encargos de control e inspección arbitrados por los estatutos para asegurar la calidad en la factura y en la enseñanza desarrollada por cada maestro, así como en los exámenes de magisterio. El experto también estaba presente en las tasaciones periciales, en las que su juicio servía para certifi car la aptitud de la obra realizada por un colega o incluso valorar su intervención. En este artículo examinaremos la noción de experto en l'art de la fusteria o carpintería medieval valenciana y en qué medida su aplicación práctica afectaba al trabajo cotidiano de un maestro carpintero en los siglos XIV al XVI. In the carpenters' guild of Valencia in the Middle Ages, experience and skill were two notions enclosed in the more comprehensive idea of expertise. The appreciation of this added value made the expert an indispensable figure, outstanding inside the guild. He was present in the different positions of control and inspection stablished in the by-law in order to ensure the required manufacture quality, the peoper lever of teaching, as well as the master of art accreditation. This figure also acted as an expert assessor to estimate the work of a colleague or even to assess the value of his intention. In this article we are going to examine the notion of the expert in medieval carpentry and the influence of his practical application in the daily routine of woodworkers

From Gabii And Gordion To Eretria And Methone: The Rise Of The Greek Alphabet

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111984/1/bics12000.pd

Excavations at Azoria, 2003–2004, Part 2: The Final Neolithic, Late Prepalatial, and Early Iron Age Occupation

This article constitutes the second of two reports on fieldwork conducted at Azoria in eastern Crete during the 2003 and 2004 excavation seasons. Evidence of Final Neolithic and Early Iron Age occupation and traces of Late Prepalatial activity were found underlying the Archaic civic buildings on the South Acropolis, particularly along the southwest terrace. The recovery of substantial Final Neolithic architectural and habitation remains contributes to our understanding of the 4th millennium in eastern Crete. Stratigraphic excavations have also clarified the spatial extent of the settlement from Late Minoan IIIC to the Late Geometric period, and brought to light evidence for the transition from the Early Iron Age to the Archaic period, and the transformation of the site in the 7th century B.C