603 research outputs found
(1,0) superconformal theories in six dimensions and Killing spinor equations
We solve the Killing spinor equations of 6-dimensional (1,0) superconformal
theories in all cases. In particular, we derive the conditions on the fields
imposed by the Killing spinor equations and demonstrate that these depend on
the isotropy group of the Killing spinors. We focus on the models proposed by
Samtleben et al in \cite{ssw} and find that there are solutions preserving 1,2,
4 and 8 supersymmetries. We also explore the solutions which preserve 4
supersymmetries and find that many models admit string and 3-brane solitons as
expected from the M-brane intersection rules. The string solitons are smooth
regulated by the moduli of instanton configurations.Comment: 26 page
unreinforced masonry buildings
A recent earthquake of M=4.9 occurred on 29 October 2007 in C, ameli, Denizli, which is located in a seismically active region at southwest Anatolia, Turkey. It has caused extensive damages at unreinforced masonry buildings like many other cases observed in Turkey during other previous earthquakes. Most of the damaged structures were non-engineered, seismically deficient, unreinforced masonry buildings. This paper presents a site survey of these damaged buildings. In addition to typical masonry damages, some infrequent, event-specific damages were also observed. Reasons for the relatively wide spread damages considering the magnitude of the event are discussed in the paper
Polarization-engineered GaN/InGaN/GaN tunnel diodes
We report on the design and demonstration of polarization-engineered
GaN/InGaN/GaN tunnel junction diodes with high current density and low
tunneling turn-on voltage. Wentzel-Kramers-Brillouin (WKB) calculations were
used to model and design tunnel junctions with narrow bandgap InGaN-based
barrier layers. N-polar p-GaN/In0.33Ga0.67N/n-GaN heterostructure tunnel diodes
were grown using molecular beam epitaxy. Efficient zero bias tunneling turn-on
with a high current density of 118 A/cm2 at a reverse bias of 1V, reaching a
maximum current density up to 9.2 kA/cm2 were obtained. These results represent
the highest current density reported in III-nitride tunnel junctions, and
demonstrate the potential of III-nitride tunnel devices for a broad range of
optoelectronic and electronic applications.Comment: 3 pages, 3 figure
Overcoming cross-cultural group work tensions: mixed student perspectives on the role of social relationships
As universities worldwide rapidly internationalise, higher education classrooms have become unique spaces for collaboration between students from different countries. One common way to encourage collaboration between diverse peers is through group work. However, previous research has highlighted that cross-cultural group work can be challenging and has hinted at potential social tensions. To understand this notion better, we have used robust quantitative tools in this study to select 20 participants from a larger classroom of 860 students to take part in an in-depth qualitative interview about cross-cultural group work experiences. Participant views on social tensions in cross-cultural group work were elicited using a unique mediating artefact method to encourage reflection and in-depth discussion. In our analysis of emergent interview themes, we compared student perspectives on the role of social relationships in group work by their academic performance level. Our findings indicated that all students interviewed desired the opportunity to form social relationships with their group work members, but their motivations for doing so varied widely by academic performance level
M-Horizons
We solve the Killing spinor equations and determine the near horizon
geometries of M-theory that preserve at least one supersymmetry. The M-horizon
spatial sections are 9-dimensional manifolds with a Spin(7) structure
restricted by geometric constraints which we give explicitly. We also provide
an alternative characterization of the solutions of the Killing spinor
equation, utilizing the compactness of the horizon section and the field
equations, by proving a Lichnerowicz type of theorem which implies that the
zero modes of a Dirac operator coupled to 4-form fluxes are Killing spinors. We
use this, and the maximum principle, to solve the field equations of the theory
for some special cases and present some examples.Comment: 36 pages, latex. Reference added, minor typos correcte
VOLTTRON Lite: Integration Platform for the Transactional Network
In FY13, Pacific Northwest National Laboratory (PNNL) with funding from the Department of Energyâs (DOEâs) Building Technologies Office (BTO) designed, prototyped and tested a transactional network platform. The platform is intended to support energy, operational and financial transactions between any networked entities (equipment, organizations, buildings, grid, etc.). Initially, in FY13, the concept demonstrated transactions between packaged rooftop units (RTUs) and the electric grid using applications or âagentsâ that reside on the platform, on the equipment, on local building controller or in the Cloud. This document describes the core of the transactional network platform, the Volttron Liteâą software and associated services hosted on the platform. Future enhancements are also discussed. The appendix of the document provides examples of how to use the various services hosted on the platform
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Long-term operation of a pilot-scale anaerobic membrane bioreactor (AnMBR) treating high salinity low loaded municipal wastewater in real environment
Supplementary material is available online at https://www.sciencedirect.com/science/article/pii/S1383586619335427?via%3Dihub#s0095 .Long term operation of an anaerobic membrane bioreactor (AnMBR) treating municipal wastewater was investigated in a real seawater intrusion spot in Falconara Marittima (Central Italy) on the Adriatic coastline. Changes in biological conversion and system stability were determined with respect to varying organic loading rate (OLR) and high salinity conditions. At an OLR of 1âŻkgâŻCODâŻm3â1âŻdâ1, biogas production was around 0.39âŻÂ±âŻ0.2âŻLâŻdâ1. The increase of the OLR to 2âŻkgâŻCODâŻm3â1âŻdâ1 resulted in increase of biogas production to 2.8âŻÂ±âŻ1.5âŻLâŻdâ1 (with 33.6%âŻÂ±âŻ10.5% of CH4) with methanol addition and to 4.11âŻÂ±âŻ3.1âŻLâŻdâ1 (with 29.7%âŻÂ±âŻ11.8% of CH4) with fermented cellulosic sludge addition. COD removal by the AnMBR was 83%âŻÂ±âŻ1% when the effluent COD concentration was below 100âŻmgâŻO2âŻLâ1. The addition of the fermented sludge affected the membrane operation and significant fouling occurred after long-term filtration, where the trans-membrane pressure (TMP) reached up to 500âŻmbar. Citric acid solution was applied to remove scalants and the TMP reached the initial value. High saline conditions of 1500âŻmgClââŻLâ1 adversely affected the biogas production without deteriorating the membrane operation. The treated effluent met the EU quality standards of the D.M. 185/2003 and the new European Commission Resolution for reuse in agriculture.This study was carried out within the framework of the âSMART-Plantâ Innovation Action which has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 690323. This study was carried out within âSafe and Sustainable Solutions for the Integrated Use of Non-Conventional Water Resources in the Mediterranean Agricultural Sector (FIT4REUSE)â which has received funding from the Partnership on Research and Innovation in the Mediterranean Area (PRIMA) under grant agreement No 1823
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