In recent years many experimentalists have reported an anomalously enhanced thermal conductivity in liquid suspensions of nanoparticles. Despite the importance of this effect for heat transfer applications, no agreement has emerged about the mechanism of this phenomenon, or even about the experimentally observed magnitude of the enhancement. To address these issues, this paper presents a combined experimental and theoretical study of heat conduction and particle agglomeration in nanofluids. On the experimental side, nanofluids of alumina particles in water and ethylene glycol are characterized using thermal conductivity measurements, viscosity measurements, dynamic light scattering, and other techniques. The results show that the particles are agglomerated, with an agglomeration state that evolves in time. The data also show that the thermal conductivity enhancement is within the range predicted by effective medium theory. On the theoretical side, a model is developed for heat conduction through a fluid containing nanoparticles and agglomerates of various geometries. The calculations show that elongated and dendritic structures are more efficient in enhancing the thermal conductivity than compact spherical structures of the same volume fraction, and that surface (Kapitza) resistance is the major factor resulting in the lower than effective medium conductivities measured in our experiments. Together, these results imply that the geometry, agglomeration state, and surface resistance of nanoparticles are the main variables controlling thermal conductivity enhancement in nanofluids.

This paper presents a novel analysis of Sluicing, an ellipsis construction first described by Ross (1969) and illustrated by the bracketed portion of 1 want to do something, but I'm just not sure [what _]. Starting from the assumption that a sluice consists of a displaced Wh-constituent and an empty IP, we show how simple and general LF operations fill out the empty IP and thereby provide it with an interpretable Logical Form. The LF operations we appeal to rely on the influential theory of indefinites developed by Irene Heim and Hans Kamp, and are in harmony with certain aspects of Chomsky's Minimalist Program for linguistic theory. The analysis accounts directly for the familiar properties of Sluicing, as well as some facts which have not previously been observed. INTRODUCTIONSluicing is the name given by Ross (1969) to the ellipsis construction bracketed in (1):(1) a. Somebody just left -guess [who]. (Ross 1969, 252) b. They claimed they had settled on something, but it wasn't dear [what].In this construction, a displaced Wh-phrase occurs in isolation in a syntactic environment where one might have expected to find a complete constituent question. Compare the sluices in (1) with the corresponding complete embedded questions in (2): (2) Our approach to the analysis of Sluicing is different from Ross's. Starting from the assumption that there is no content in the d-structure of a sluice corresponding to the ellipsis, we ask how this radically reduced structure is interpreted. Our answer is that the interpretation is read off a Logical Form which is constructed for the sluice via simple and principled LF operations.Here we present and motivate the LF operations that supply a Logical Form for sluices. Our overall aims are two: First, we argue that our LF approach offers the best available account of Sluicing (other accounts can be found in Ross 1969;Rosen 1976;Williams 1977;Levin 1982;Chao 1987;Lobeck 1991Lobeck , 1992and Ginzburg 1992). Second, we show that the LF operations we appeal to are both general and well-behaved -almost expected -from the viewpoint of current syntactic and semantic theory. If we are correct, then the existence of this ellipsis construction, which seemed rather arcane when first documented by Ross, follows immediately from the overall architecture of the LF component and the operations it makes available. In this sense, our investigation can be read as an extended argument in favor of a certain conception of Logical Form.

for discussion, questions and commentary which helped shape the final version. I am particularly grateful to Noam Chomsky for a very detailed and penetrating commentary on an earlier version of the paper. Not all of the issues which arose in that correspondence can be dealt with in the space of this revision.

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This article analyzes mismatches between syntactic and prosodic constituency in Irish and attempts to understand those mismatches in terms of recent proposals about the nature of the syntax-prosody interface. It argues in particular that such mismatches are best understood in terms of Selkirk's (2011) Match Theory, working in concert with constraints concerned with rhythm and phonological balance. An apparently anomalous rightward movement that seems to target certain pronouns and shift them rightward is shown to be fundamentally a phonological process: a prosodic response to a prosodic dilemma. The article thereby adds to a growing body of evidence for the role of phonological factors in shaping constituent order.