Inertial and non-inertial focusing of a deformable capsule in a curved microchannel

A computational study is presented on cross-stream migration and focusing of deformable capsules in curved microchannels of square and rectangular sections under inertial and non-inertial regimes. The numerical methodology is based on immersed boundary methods for fluid–structure coupling, a finite-volume-based flow solver and finite-element method for capsule deformation. Different focusing behaviours in the two regimes are predicted that arise due to the interplay of inertia, deformation, altered shear gradient, streamline curvature effect and secondary flow. In the non-inertial regime, a single-point focusing occurs on the central plane, and at a radial location between the interior face (i.e. face with highest curvature) of the channel and the location of zero shear. The focusing position is nearly independent of capsule deformability (represented by the capillary number, $Ca$ ). A two-step migration is observed that is comprised of a faster radial migration, followed by a slower migration toward the centre plane. The focusing location progressively moves further toward the interior face with increasing curvature and width, but decreasing height. In the inertial regime, single-point focusing is observed near the interior face for channel Reynolds number $Re_{C}\sim {O}(1)$ , that is also highly sensitive to $Re_{C}$ and $Ca$ , and moves progressively toward the exterior face with increasing $Re_{C}$ but decreasing $Ca$ . As $Re_{C}$ increases by an order, secondary flow becomes stronger, and two focusing locations appear close to the centres of the Dean vortices. This location becomes practically independent of $Ca$ at even higher inertia. The inertial focusing positions move progressively toward the exterior face with increasing channel width and decreasing height. For wider channels, the equilibrium location is further toward the exterior face than the vortex centre.

Influence of the Water Vapour Permeability of Airtight Sheets on the Behaviour of Facade

The air-tightness of the thermal envelope of buildings is one of the measures to reduce their energy demands in order to achieve global warming reduction targets. To this end, airtight sheets with different water vapour permeability characteristics are used. The different products studied are highly dispersed in terms of equivalent air thickness values, leading to confusion. After the analysis carried out, it is concluded that all airtight sheets are vapour barriers. To clarify whether or not these sheets are necessary as vapour barriers, a condensation analysis was carried out on 13 different facades for 3 climate zones with severe winters as defined in Spanish regulations. The results reveal that interstitial condensation occurs in only 7 of the 39 case studies, with the traditional facades of brickwork with render causing the greatest problems if the appropriate products are not used. In these cases, airtight sheets with water vapour barrier characteristics must be applied on the interior face of the insulating material. In all other cases (32), the airtight sheets must be permeable to water vapour if it is looked for a more breathable wall to water vapour and a better control of the interior humidity conditions.

Use of hygrothermal modeling to validate the application of an open-cell spray-foam insulation application to a high-rise heritage building in Winnipeg, Manitoba

The increasing cost of new building construction has made repurposing existing building stock economically more viable compared with a green site new build. In addition to capital cost benefits, increasing urban densification through repurposing existing buildings is one of the solutions for enhancing the urban environment. This paper summarizes the investigative work completed to substantially improve the energy efficiency of a heritage 10 storey building in Winnipeg, Manitoba. The investigative work for the remediation involved hygrothermal modeling to rationalize the introduction of thermal insulation to the interior face of the exterior walls. Based on the modelling, an open-cell spray foam was applied to the interior face of the masonry walls. Temperature, moisture, and relative humidity sensors were placed in various locations throughout the building to monitor the exterior walls, primarily to identify if deleterious levels of moisture were accumulating in the masonry. The results were also used to compare the in-situ performance of the building with the predicted performance from the hygrothermal models. The investigation confirmed that obtaining accurate in-situ moisture readings in masonry products is significantly impacted by initial internal moisture levels, necessitating pre-test calibration. Regardless, moisture sensor data accumulated to date indicate that after six years of monitoring, deleterious levels of moisture in the masonry and plaster are not occurring in the exterior walls, which is in good agreement with hygrothermal model results for open-cell foam. The results of this investigation confirm that the implementation of hygrothermal modeling is an effective and accurate analysis tool in the long-term durability assessment of building envelopes for heritage buildings.

Revision and phylogeny of Chelagyrtodes Szymczakowski (Coleoptera: Leiodidae: Camiarinae: Agyrtodini)

The formerly monotypic New Zealand leiodid genus Chelagyrtodes Szymczakowski (type species Chelagyrtodes crowsoni Szymczakowski) is revised to include five new species from the South Island: C. newtoni n. sp., C. rotundus n. sp., C. haasti n. sp., C. glacicola n. sp., and C. davidi n. sp. Four of these new species lack the unusual tibial dimorphism previously used to diagnose this genus, but can be recognized by the presence of a subapical spine cluster on the interior face of the mandible, procoxal cavities with an anterior carina or bead, and a series of minute, setiferous punctures along the lateral margins of the hypomeron. A key and phylogenetic analysis based on adult morphology is provided for the six species of Chelagyrtodes. Natural history and distribution of Chelagyrtodes are discussed in the context of phylogenetic data.

A New Context for Rock Art: a Late Neolithic and Early Bronze Age Ritual Monument at Fylingdales, North Yorkshire

After fire swept across 2.5 km2 of heather moorland the detail of a wide range of archaeological features was revealed. Among these was a so-far unique small circular monument, the principal component of which was a circle of near-upright slabs set in a shallow trench. The stones included one with a complex pecked geometric design reminiscent of some Grooved Ware ceramic decoration, and another with more commonly found cup-mark and linear motifs. Limited excavation was undertaken in response to disturbance of the monument and it was discovered that the stone with complex decoration had been reshaped for its monumental setting, having perhaps previously been a free-standing decorated monolith. In its altered form the stone formed part of a small circular arena, the interior face of which may have included alternating decorated and undecorated stones. The open arena had later been filled with rubble creating a small cairn, its material including a small block detached from the main stone as well as a number of cup- and other marked stones. Apart from the decorated stones there were no diagnostic artefacts and no direct dating information was present. It is suggested that the decorated stones originate in the later Neolithic period and that the monument containing them was constructed in the Early Bronze Age.

Nup2p is located on the nuclear side of the nuclear pore complex and coordinates Srp1p/importin-alpha export

Proteins bearing canonical nuclear localization sequences are imported into the nucleus by the importin/karyopherin-alpha/beta heterodimer. Recycling of the importin-alpha subunit to the cytoplasm requires the action of Cas, a member of the importin-beta superfamily. In the yeast Saccharomyces ceresivisiae, the essential gene CSE1 encodes a Cas homologue that exports the yeast importin-alpha protein Srp1p/Kap60p from the nucleus. In this report, we describe a role for the FXFG nucleoporin Nup2p, and possibly the related Nup1p, in the Cse1p-mediated nuclear export pathway. Yeast cells lacking Nup2p or containing a particular temperature-sensitive mutation in NUP1 accumulate Srp1p in the nucleus. Similarly, Cse1p is displaced from the nuclear rim to the nuclear interior in deltanup2 cells. We do not observe any biochemical interaction between Cse1p and Nup2p. Instead, we find that Nup2p binds directly to Srp1p. We have localized Nup2p to the interior face of the nuclear pore complex, and have shown that its N terminus is sufficient for targeting Nup2p to the pore, as well as for binding to Srp1p. Taken together, these data suggest that Nup2p is an important NPC docking site in the Srp1p export pathway.