1,265 research outputs found
Assessing the influence of the Merzbacher Lake outburst floods on discharge using the hydrological model SWIM in the Aksu headwaters, Kyrgyzstan/NW China
Glacial lake outburst floods (GLOF) often have a significant impact on downstream users. Including their effects in hydrological models, identifying past occurrences and assessing their potential impacts are challenges for hydrologists working in mountainous catchments. The regularly outbursting Merzbacher Lake is located in the headwaters of the Aksu River, the most important source of water discharge to the Tarim River, northwest China. Modelling its water resources and the evaluation of potential climate change impacts on river discharge are indispensable for projecting future water availability for the intensively cultivated river oases downstream of the Merzbacher Lake and along the Tarim River. The semi-distributed hydrological model SWIM was calibrated to the outlet station Xiehela on the Kumarik River, by discharge the largest tributary to the Aksu River. The glacial lake outburst floods add to the difficulties of modelling this high-mountain, heavily glaciated catchment with poor data coverage and quality. The aims of the study are to investigate the glacier lake outburst floods using a modelling tool. Results include a two-step model calibration of the Kumarik catchment, an approach for the identification of the outburst floods using the measured gauge data and the modelling results and estimations of the outburst flood volumes. Results show that a catchment model can inform GLOF investigations by providing ‘normal’ (i.e. without the outburst floods) catchment discharge. The comparison of the simulated and observed discharge proves the occurrence of GLOFs and highlights the influences of the GLOFs on the downstream water balance. © 2013 The Authors. Hydrological Processes Published by John Wiley & Sons Ltd
Topological Crystalline Insulator and Quantum Anomalous Hall States in IV-VI based Monolayers and their Quantum Wells
Different from the two-dimensional (2D) topological insulator, the 2D
topological crystalline insulator (TCI) phase disappears when the mirror
symmetry is broken, e.g., upon placing on a substrate. Here, based on a new
family of 2D TCIs - SnTe and PbTe monolayers - we theoretically predict the
realization of the quantum anomalous Hall effect with Chern number C = 2 even
when the mirror symmetry is broken. Remarkably, we also demonstrate that the
considered materials retain their large-gap topological properties in quantum
well structures obtained by sandwiching the monolayers between NaCl layers. Our
results demonstrate that the TCIs can serve as a seed for observing robust
topologically non-trivial phases.Comment: 5 pages, submitted on 27th Feb 201
Observation of a temperature dependent electrical resistance minimum above the magnetic ordering temperature in GdPdSi
Results on electrical resistivity, magnetoresistance, magnetic Results on
electrical resistivity, magnetoresistance, magnetic susceptibility, heat
capacity and Gd Mossbauer measurements on a Gd-based intermetallic compound,
GdPdSi are reported. A finding of interest is that the resistivity
unexpectedly shows a well-defined minimum at about 45 K, well above the long
range magnetic ordering temperature (21 K), a feature which gets suppressed by
the application of a magnetic field. This observation in a Gd alloy presents an
interesting scenario. On the basis of our results, we propose electron
localization induced by s-f (or d-f) exchange interaction prior to long range
magnetic order as a mechanism for the electrical resistance minimum.Comment: 4 pages, 4 figure
JME 4110 PheNode Camera Arm Design Project
The goal of this design project was to create an extendable camera arm capable of attaching to the shell of the PheNode in-field apparatus created by researchers at the Donald Danforth Plant Science Center. The camera arm extends 36 inches in length, can rotate 180 degrees, and successfully holds a camera for plant imaging with minimal vibrations. We have designed an affordable camera arm that is stable and meets the design parameters given. Our design process is documented in the following report
Mixed topological semimetals driven by orbital complexity in two-dimensional ferromagnets
The concepts of Weyl fermions and topological semimetals emerging in
three-dimensional momentum space are extensively explored owing to the vast
variety of exotic properties that they give rise to. On the other hand, very
little is known about semimetallic states emerging in two-dimensional magnetic
materials, which present the foundation for both present and future information
technology. Here, we demonstrate that including the magnetization direction
into the topological analysis allows for a natural classification of
topological semimetallic states that manifest in two-dimensional ferromagnets
as a result of the interplay between spin-orbit and exchange interactions. We
explore the emergence and stability of such mixed topological semimetals in
realistic materials, and point out the perspectives of mixed topological states
for current-induced orbital magnetism and current-induced domain wall motion.
Our findings pave the way to understanding, engineering and utilizing
topological semimetallic states in two-dimensional spin-orbit ferromagnets
Density of Phonon States in Superconducting FeSe as a Function of Temperature and Pressure
The temperature and pressure dependence of the partial density of phonon
states of iron atoms in superconducting Fe1.01Se was studied by 57Fe nuclear
inelastic scattering (NIS). The high energy resolution allows for a detailed
observation of spectral properties. A sharpening of the optical phonon modes
and shift of all spectral features towards higher energies by ~4% with
decreasing temperature from 296 K to 10 K was found. However, no detectable
change at the tetragonal - orthorhombic phase transition around 100 K was
observed. Application of a pressure of 6.7 GPa, connected with an increase of
the superconducting temperature from 8 K to 34 K, results in an increase of the
optical phonon mode energies at 296 K by ~12%, and an even more pronounced
increase for the lowest-lying transversal acoustic mode. Despite these strong
pressure-induced modifications of the phonon-DOS we conclude that the
pronounced increase of Tc in Fe1.01Se with pressure cannot be described in the
framework of classical electron-phonon coupling. This result suggests the
importance of spin fluctuations to the observed superconductivity
Panel 3 Acquiring and Implementing ERP: The View from Business and Academia
Since the early days of computing, organizations have aspired to integrated, enterprise-wide information systems architectures. Through the years, these aspirations have been reflected in the quest for integrated MIS, enterprise-wide data models, and integrated databases. In recent years, with the increasing demand for process integration both within and across organizational and industry boundaries, this quest has gained further momentum. Enterprise resource planning (ERP) systems, such as SAP, BaaN, Peoplesoft, and Oracle, are a recent business response to this quest. By providing integrated packaged solutions, not only do they provide an integrated system architecture for the organizations’ information processing needs, they also claim to provide ready-made “best-of-the-breed” solutions for particular lines of businesses. Furthermore, given their enterprise-wide scope and extensive impact on organizational and interorganizational business practices, the acquisition and implementation of these systems substantially affects both the organization and the nature of corporate IS practices and the responsibilities of corporate IS departments. While a number of high profile organizations such as Boeing, Mercedes-Benz, ABB, and Levi have recently adopted ERP as an integrated replacement for their enterprise-wide information infrastructure, recent press reports outline a number of issues with the adoption and implementation of ERP systems. Moreover, the adoption of so-called “best-of-breed” applications raises a number of questions about the appropriateness and value of cookie-cutter solutions to diverse organizational requirements
Patients' appreciation of pre-implant augmentation of the severely resorbed maxilla with calvarial or anterior iliac crest bone:a randomized controlled trial
BACKGROUND: Little is known about the impact of bone graft harvesting for pre-implant augmentation of the maxilla from a patient's perspective. To assess patient-reported outcome measures (PROMs) related to augmentation of the extremely resorbed edentulous maxilla with calvarial or anterior iliac crest bone. MATERIALS AND METHODS: For this randomised controlled trial, 20 consecutive edentulous patients needing extensive pre-implant surgery of the maxilla were randomly assigned to either calvarial (n = 10) or anterior iliac crest (n = 10) bone harvesting. Patient reports on procedure-related satisfaction, questionnaires on oral functionality (denture satisfaction, chewing ability) and oral health-related quality of life (OHIP-49NL) and subjective donor site-related outcomes (e.g. of post-operative pain, scar formation, physical mobility) were assessed. RESULTS: Irrespective of the harvesting site, patients were generally satisfied (median VAS score 93 (86-99) mm, p = 0.400) with the procedure and its final results. Post-operative pain was mild (median 40 (20-40) mm) and decreased to no pain (4 (0-16) mm) within 14 days. Early post-operative pain was significantly higher following anterior iliac crest harvesting (p < 0.00). Impact on physical mobility, daily functioning and satisfaction with the scar formation were similar in both groups. CONCLUSIONS: The assessed PROMs confirmed that bone graft harvesting from the calvarium or anterior iliac crest is an appropriate procedure, reflected by high levels of satisfaction, minor long-term sequela and improvement of perceived oral health. For clinical decision-making, decisions can be based on individual features and preferences. TRIAL REGISTRATION: NTR, NTR3968 , registered 1 July 2013
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