STR-863: DEVELOPMENT OF A NOVEL REPLACEABLE CONNECTION FOR SEISMICALLY DESIGNED STEEL CONCENTRICALLY BRACED FRAMES

There is increasing demand, from both engineers and their clients, for structures that can be rapidly returned to occupancy following an earthquake, while also maintaining or reducing initial costs. One possible way towards this goal is to ensure that seismic damage occurs only within elements that can be removed and replaced following a damaging earthquake. For concentrically braced frames that use hollow structural sections, the current design practice requires field welding of the brace to the gusset in a way that causes the brace to buckle out-of-plane. In the event of a damaging earthquake, the out-of-plane brace buckling may damage both the gusset plate and also any adjacent exterior cladding. The plate cannot be easily replaced, resulting in expensive and time-consuming repairs, and the damaged cladding could endanger the lives of people evacuating the building and of other pedestrians. This paper discusses the development of an alternative connection that can be bolted into place and that confines damage to replaceable components. The proposed connection is expected to result in reduced erection costs and be easier to repair following a major earthquake. Moreover, the new connection causes buckling to occur in plane, preventing dangerous damage to the cladding. Potential challenges in the design of such a connection are discussed and evaluated, and a finite element model that was created to confirm the performance of the proposed connection is also introduced. Finally, future areas of research and development of the connection are identified

Exercise Training in Children and Adolescents with Cystic Fibrosis: Theory into Practice

Physical activity and exercise training play an important role in the clinical management of patients with cystic fibrosis (CF). Exercise training is more common and recognized as an essential part of rehabilitation programmes and overall CF care. Regular exercise training is associated with improved aerobic and anaerobic capacity, higher pulmonary function, and enhanced airway mucus clearance. Furthermore, patients with higher aerobic fitness have an improved survival. Aerobic and anaerobic training may have different effects, while the combination of both have been reported to be beneficial in CF. However, exercise training remains underutilised and not always incorporated into routine CF management. We provide an update on aerobic and anaerobic responses to exercise and general training recommendations in children and adolescents with CF. We propose that an active lifestyle and exercise training are an efficacious part of regular CF patient management

Measuring Condensation Heat Transfer on Superhydrophobic Surfaces

Condensation heat transfer is significant in many applications such as desalination, energy conversion, atmospheric water harvesting, electronics cooling, and other high heat flux applications. However, condensate on the surface adds a thermal resistance that limits condensation rates. The rate of condensation heat transfer is inversely proportional to the diameter of the condensate drops. In industrial condensing systems, the resistance is minimized by removing the condensate via gravity or a vapor shear, but the minimum size of droplet removal is typically on the order of the capillary length of the condensate, about 2.7 mm for water

Assessing the Gene Content of the Megagenome: Sugar Pine (Pinus lambertiana).

Sugar pine (Pinus lambertiana Douglas) is within the subgenus Strobus with an estimated genome size of 31 Gbp. Transcriptomic resources are of particular interest in conifers due to the challenges presented in their megagenomes for gene identification. In this study, we present the first comprehensive survey of the P. lambertiana transcriptome through deep sequencing of a variety of tissue types to generate more than 2.5 billion short reads. Third generation, long reads generated through PacBio Iso-Seq have been included for the first time in conifers to combat the challenges associated with de novo transcriptome assembly. A technology comparison is provided here to contribute to the otherwise scarce comparisons of second and third generation transcriptome sequencing approaches in plant species. In addition, the transcriptome reference was essential for gene model identification and quality assessment in the parallel project responsible for sequencing and assembly of the entire genome. In this study, the transcriptomic data were also used to address questions surrounding lineage-specific Dicer-like proteins in conifers. These proteins play a role in the control of transposable element proliferation and the related genome expansion in conifers

An Optical-based Aggregate Approach to Measuring Condensation Heat Transfer

Condensation heat transfer is significant in many applications such as such as desalination, energy conversion [1], atmospheric water harvesting [2, 3], electronics cooling, and other high heat flux applications [4]. However, condensate on the surface adds a thermal resistance that limits condensation rates. The rate of condensation heat transfer is inversely proportional to the diameter of the condensate drops [5]. In industrial condensing systems, the resistance is minimized by removing the condensate via gravity or a vapor shear, but the minimum size of droplet removal is typically on the order of the capillary length of the condensate, about 2.7 mm for water

A Burst-Based “Hebbian” Learning Rule at Retinogeniculate Synapses Links Retinal Waves to Activity-Dependent Refinement

Patterned spontaneous activity in the developing retina is necessary to drive synaptic refinement in the lateral geniculate nucleus (LGN). Using perforated patch recordings from neurons in LGN slices during the period of eye segregation, we examine how such burst-based activity can instruct this refinement. Retinogeniculate synapses have a novel learning rule that depends on the latencies between pre- and postsynaptic bursts on the order of one second: coincident bursts produce long-lasting synaptic enhancement, whereas non-overlapping bursts produce mild synaptic weakening. It is consistent with “Hebbian” development thought to exist at this synapse, and we demonstrate computationally that such a rule can robustly use retinal waves to drive eye segregation and retinotopic refinement. Thus, by measuring plasticity induced by natural activity patterns, synaptic learning rules can be linked directly to their larger role in instructing the patterning of neural connectivity

Seismicity on the western Greenland Ice Sheet : surface fracture in the vicinity of active moulins

Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Earth Surface 120 (2015): 1082–1106, doi:10.1002/2014JF003398.We analyzed geophone and GPS measurements collected within the ablation zone of the western Greenland Ice Sheet during a ~35 day period of the 2011 melt season to study changes in ice deformation before, during, and after a supraglacial lake drainage event. During rapid lake drainage, ice flow speeds increased to ~400% of winter values, and icequake activity peaked. At times >7 days after drainage, this seismicity developed variability over both diurnal and longer periods (~10 days), while coincident ice speeds fell to ~150% of winter values and showed nightly peaks in spatial variability. Approximately 95% of all detected seismicity in the lake basin and its immediate vicinity was triggered by fracture propagation within near-surface ice (<330 m deep) that generated Rayleigh waves. Icequakes occurring before and during drainage frequently were collocated with the down flow (west) end of the primary hydrofracture through which the lake drained but shifted farther west and outside the lake basin after the drainage. We interpret these results to reveal vertical hydrofracture opening and local uplift during the drainage, followed by enhanced seismicity and ice flow on the downstream side of the lake basin. This region collocates with interferometric synthetic aperture radar-measured speedup in previous years and could reflect the migration path of the meltwater supplied to the bed by the lake. The diurnal seismic signal can be associated with nightly reductions in surface melt input that increase effective basal pressure and traction, thereby promoting elevated strain in the surficial ice.Research by J. Carmichael was supported by a NASA NESSF Fellowship grant NNX08AU82H and NSF grant ANT-0424589. The fieldwork and additional analyses were supported by the National Science Foundation's Office of Polar Programs (NSF-OPP) through ARC-1023382, awarded to I. Joughin, and ARC-1023364, awarded to S. B. Das and M. D. Behn. Matt King is a recipient of an Australian Research Council Future Fellowship (project number FT110100207).2015-12-2