113 research outputs found
Assessing debris flows using LIDAR differencing: 18 May 2005 Matata event, New Zealand
The town of Matata in the Eastern Bay of Plenty (New Zealand) experienced an extreme rainfall event on the 18 May 2005. This event triggered widespread landslips and large debris flows in the Awatarariki and Waitepuru catchments behind Matata. The Light Detection and Ranging technology (LIDAR) data sets flown prior to and following this event have been differenced and used in conjunction with a detailed field study to identify the distribution of debris and major sediment pathways which, from the Awatarariki catchment, transported at least 350,000 ± 50,000 m3 of debris. Debris flows were initially confined to stream valleys and controlled by the density and hydraulic thrust of the currents, before emerging onto the Awatarariki debris fan where a complex system of unconfined sediment pathways developed. Here, large boulders, clasts, logs and entire homes were deposited as the flows decelerated. Downstream from the debris fan, the pre-existing coastal foredune topography played a significant role in deflecting the more dilute currents that in filled lagoonal swale systems in both directions. The differenced LIDAR data have revealed several sectors characterised by significant variation in clast size, thickness and volume of debris as well as areas where post-debris flow cleanup and grading operations have resulted in man-made levees, sediment dumps, scoured channels and substantial graded areas. The application of differenced LIDAR data to a debris flow event demonstrates the techniques potential as a precise and powerful tool for hazard mapping and assessment
Experimental validation of a short-term Borehole-to-Ground (B2G) dynamic model
[EN] The design and optimization of ground source heat pump systems require the ability to accurately reproduce the dynamic thermal behavior of the system on a short-term basis, specially in a system control perspective. In this context, modeling borehole heat exchangers (BHEs) is one of the most relevant and difficult tasks. Developing a model that is able to accurately reproduce the instantaneous response of a BHE while keeping a good agreement on a long-term basis is not straightforward. Thus, decoupling the short-term and long-term behavior will ease the design of a fast short-term focused model. This work presents a short-term BHE dynamic model, called Borehole-to-Ground (B2G), which is based on the thermal network approach, combined with a vertical discretization of the borehole.
The proposed model has been validated against experimental data from a real borehole located in Stockholm, Sweden. Validation results prove the ability of the model to reproduce the short-term behavior of the borehole with an accurate prediction of the outlet fluid temperature, as well as the internal temperature profile along the U-tube.The present work has been supported by the FP7 European project "Advanced ground source heat pump systems for heating and cooling in Mediterranean climate" (GROUND-MED), and by the "Resource-Efficient Refrigeration And Heat Pump Systems" (EFF-SYS+) program.Ruiz Calvo, F.; Rosa, MD.; Acuña, J.; Corberán Salvador, JM.; Montagud Montalvá, CI. (2015). Experimental validation of a short-term Borehole-to-Ground (B2G) dynamic model. Applied Energy. 140:210-223. https://doi.org/10.1016/j.apenergy.2014.12.002S21022314
Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA
An investigation of the hadronic final state in diffractive and
non--diffractive deep--inelastic electron--proton scattering at HERA is
presented, where diffractive data are selected experimentally by demanding a
large gap in pseudo --rapidity around the proton remnant direction. The
transverse energy flow in the hadronic final state is evaluated using a set of
estimators which quantify topological properties. Using available Monte Carlo
QCD calculations, it is demonstrated that the final state in diffractive DIS
exhibits the features expected if the interaction is interpreted as the
scattering of an electron off a current quark with associated effects of
perturbative QCD. A model in which deep--inelastic diffraction is taken to be
the exchange of a pomeron with partonic structure is found to reproduce the
measurements well. Models for deep--inelastic scattering, in which a
sizeable diffractive contribution is present because of non--perturbative
effects in the production of the hadronic final state, reproduce the general
tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil
A Measurement of the Proton Structure Function
A measurement of the proton structure function is reported
for momentum transfer squared between 4.5 and 1600 and
for Bjorken between and 0.13 using data collected by the
HERA experiment H1 in 1993. It is observed that increases
significantly with decreasing , confirming our previous measurement made
with one tenth of the data available in this analysis. The dependence is
approximately logarithmic over the full kinematic range covered. The subsample
of deep inelastic events with a large pseudo-rapidity gap in the hadronic
energy flow close to the proton remnant is used to measure the "diffractive"
contribution to .Comment: 32 pages, ps, appended as compressed, uuencoded fil
Active interplay between strike-slip and extensional structures in a back-arc environment, Bay of Plenty, New Zealand
(paper presented at American Geophysical Union - Fall Meeting, San Francisco, 8-12 Dec 2003
The Adsorption of Cement Superplasticizers on to Mineral Dispersions
The adsorption of polymeric sulphonated naphthalene formaldehyde (SNF) and sulphonated melamine formaldehyde (SMF) on to titanium dioxide and calcium carbonate has been measured in aqueous media. The magnitude of these adsorptions is strongly dependent on electrostatic interaction irrespective of the pH value. This result has been established by studying the adsorption of the polyelectrolytes from solutions of different composition. The calcium ion plays a prominent role in the process of adsorption, especially at high pH where electrical interactions do not favour the reaction. The polymeric nature of the fluidizing agents is demonstrated by an increase in adsorption with molecular weight and by adsorption/desorption experiments where the reaction has been shown to be irreversible. The amount adsorbed at maximum coverage does not depend on the nature of the mineral, but mainly on electrical interactions between the monomer units
Normal fault growth and linkage in the Whakatane Graben, New Zealand, during the last 1.3 million years (abstract of paper presented at AGU Fall Meeting, San Francisco, 8-12 Dec 2003)
Constraining fault growth rates and fault evolution in New Zealand
Understanding how faults propagate, grow and interact in fault systems is important because they are primarily responsible for the distribution of strain in the upper crust. They localise deformation and stress release, often producing surface displacements that control sedimentation and fluid flow either by acting as conduits or barriers. Identifying fault spatial distribution, quantifying activity, evaluating linkage mechanism, and estimating fault growth rates are key components in seismic risk evaluation.
Scientists from the National Institute of Water and Atmospheric Research (NIWA), New Zealand, and the Southampton Oceanography Centre (UK) are working on a collaborative project which aims to improve understanding of the processes of faulting in the Earth’s crust. The program comprises two research cruises to survey the Whakatane Graben, New Zealand, which is a zone of intense seismicity, active extensional faulting, and rapid subsidence within the back-arc region of the Pacific-Australia plate boundary zone (Fig. 1). Few places in the world offer the same potential to study the mechanisms by which major crustal faults have grown from small to large scale structures capable of generating moderate to large magnitude earthquakes. The aim of the project it to provide new insights into fundamental questions such as: (i) how do faults interact and link together to form fault systems, and (ii) how do fault propagation and linkage change with time? One of the most exciting results from the work in the Whakatane Graben is the potential for improving understanding of how and at what rates faults grow.
The first survey was funded by the New Zealand Foundation for Research Science and Technology (FRST), and took place in November 1999 during which conventional marine geophysical data were collected. The second cruise is funded by the British Natural Environment Research Council (NERC), and is scheduled for January 2001. It will focus on the acquisition of high frequency shallow seismic and sidescan sonar data
. This study of the Whakatane Graben will represent the most detailed regional investigation of active marine faults undertaken anywhere in the New Zealand region. Arguably, it could also become a case study of extensional fault growth and continental rift development of global significance.<br/
A morphometric study of mechanotransductively induced dermal neovascularization.
BACKGROUND:: Mechanical stretch has been shown to induce vascular remodeling and increase vessel density, but the pathophysiologic mechanisms and the morphologic changes induced by tensile forces to dermal vessels are poorly understood.
METHODS:: A custom computer-controlled stretch device was designed and applied to the backs of C57BL/6 mice (n = 38). Dermal and vascular remodeling was studied over a 7-day period. Corrosion casting and three-dimensional scanning electron microscopy and CD31 staining were performed to analyze microvessel morphology. Hypoxia was assessed by immunohistochemistry. Western blot analysis of vascular endothelial growth factor (VEGF) and mRNA expression of VEGF receptors was performed.
RESULTS:: Skin stretching was associated with increased angiogenesis as demonstrated by CD31 staining and vessel corrosion casting where intervascular distance and vessel diameter were decreased (p < 0.01). Immediately after stretching, VEGF dimers were increased. Messenger RNA expression of VEGF receptor 1, VEGF receptor 2, neuropilin 1, and neuropilin 2 was increased starting as early as 2 hours after stretching. Highly proliferating epidermal cells induced epidermal hypoxia starting at day 3 (p < 0.01).
CONCLUSIONS:: Identification of significant hypoxic cells occurred after identification of neovessels, suggesting an alternative mechanism. Increased expression of angiogenic receptors and stabilization of VEGF dimers may be involved in a mechanotransductive, prehypoxic induction of neovascularization
Berlinde de Bruyckere. Mit Texten von E. Alloa, G. Carrion-Murayari, A. Mengoni Ed. Marc Fehlmann, Birgit Verwiebe
Mit ihren Werken hat die belgische Künstlerin Berlinde De Bruyckere in den vergangenen Jahren weltweit große Anerkennung erfahren. 2013 bespielte sie den belgischen Pavillon auf der Biennale in Venedig mit ihrer Installation "Kreupelhout", die zumPublikumsrenner avancierte. Das ist die erste Monografie ihres ouvres der letzten zwanzig Jahre auf Deutsch. Das Werk von Berlinde De Bruyckere geht im wahrsten Sinne des Wortes unter die Haut. Ihre Skulpturen und Installationen führen die Verletzlichkeit des menschlichen Körpers vor Augen. In expressiven Arbeiten aus Wachs, Holz, Wolle, Stofffetzen oder Tierfellen thematisiert sie Leben und Tod, Einsamkeit und Fragilität von Mensch, Tier und Pflanzenwelt. Die verstörende Wucht ihrer beeindruckenden Arbeiten kommt in großformatigen Abbildungen intensiv zum Tragen. In enger Zusammenarbeit mit De Bruyckere entstand das aufwendige Layout dieser Publikation. Drei philosophische Essays reflektieren das Werk dieser besonderen Künstlerin und regen den Leser zum Nachdenken über die menschliche Existenz an
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