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A review of microgrid development in the United States – A decade of progress on policies, demonstrations, controls, and software tools
Microgrids have become increasingly popular in the United States. Supported by favorable federal and local policies, microgrid projects can provide greater energy stability and resilience within a project site or community. This paper reviews major federal, state, and utility-level policies driving microgrid development in the United States. Representative U.S. demonstration projects are selected and their technical characteristics and non-technical features are introduced. The paper discusses trends in the technology development of microgrid systems as well as microgrid control methods and interactions within the electricity market. Software tools for microgrid design, planning, and performance analysis are illustrated with each tool's core capability. Finally, the paper summarizes the successes and lessons learned during the recent expansion of the U.S. microgrid industry that may serve as a reference for other countries developing their own microgrid industries
Signature of structure failure using asymmetric and broadening factors of brillouin spectrum
Copyright © 2005 IEEEWe introduce a novel data analysis approach based on the extraction of peak strain, asymmetric and broadening factors of the Brillouin spectrum measured with the distributed Brillouin sensor (DBS). Such an approach provides simultaneously global and local strains, describing the status of the structure, at the contrary of average strain measurements. These results are confirmed by a trial on a composite column subjected to vertical and bending loads. This demonstrates that the DBS is a powerful tool to give the signature of the structure failure and then to identify early problems in structures that none of existing point sensors can detect.Fabien Ravet, Xiaoyi Bao, Togay Ozbakkaloglu, and Murat Saatciogl
A Novel Large Moment Antiferromagnetic Order in K0.8Fe1.6Se2 Superconductor
The discovery of cuprate high Tc superconductors has inspired searching for
unconventional su- perconductors in magnetic materials. A successful recipe has
been to suppress long-range order in a magnetic parent compound by doping or
high pressure to drive the material towards a quantum critical point, which is
replicated in recent discovery of iron-based high TC superconductors. The
long-range magnetic order coexisting with superconductivity has either a small
magnetic moment or low ordering temperature in all previously established
examples. Here we report an exception to this rule in the recently discovered
potassium iron selenide. The superconducting composition is identified as the
iron vacancy ordered K0.8Fe1.6Se2 with Tc above 30 K. A novel large moment 3.31
{\mu}B/Fe antiferromagnetic order which conforms to the tetragonal crystal
symmetry has the unprecedentedly high an ordering temperature TN = 559 K for a
bulk superconductor. Staggeredly polarized electronic density of states thus is
suspected, which would stimulate further investigation into superconductivity
in a strong spin-exchange field under new circumstance.Comment: 5 figures, 5 pages, and 2 tables in pdf which arXiv.com cannot tak
High-yield TiO(2) nanowire synthesis and single nanowire field-effect transistor fabrication
We report a facile method for synthesizing single-crystal rutile TiO 2 nanowires using atmospheric-pressure, chemical vapor deposition with Ti and TiO as precursors. The synthesis is found to depend critically on the predeposition of a layer of metallic Ti on the Ni catalysts layer. The omission of this step seems previously to have impeded the efficient synthesis of titania nanowires. Single-nanowire field-effect transistors showed the TiO2 nanowires to be n -type semiconductors with conductance activation energy of ???58 meV.open242
DancingLines: An Analytical Scheme to Depict Cross-Platform Event Popularity
Nowadays, events usually burst and are propagated online through multiple
modern media like social networks and search engines. There exists various
research discussing the event dissemination trends on individual medium, while
few studies focus on event popularity analysis from a cross-platform
perspective. Challenges come from the vast diversity of events and media,
limited access to aligned datasets across different media and a great deal of
noise in the datasets. In this paper, we design DancingLines, an innovative
scheme that captures and quantitatively analyzes event popularity between
pairwise text media. It contains two models: TF-SW, a semantic-aware popularity
quantification model, based on an integrated weight coefficient leveraging
Word2Vec and TextRank; and wDTW-CD, a pairwise event popularity time series
alignment model matching different event phases adapted from Dynamic Time
Warping. We also propose three metrics to interpret event popularity trends
between pairwise social platforms. Experimental results on eighteen real-world
event datasets from an influential social network and a popular search engine
validate the effectiveness and applicability of our scheme. DancingLines is
demonstrated to possess broad application potentials for discovering the
knowledge of various aspects related to events and different media
Interaction of oxygen with silver at high temperature and atmospheric pressure: A spectroscopic and structural analysis of a strongly bound surface species
X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy (UPS), and ion scattering spectroscopy (ISS) have been used to study the Ag(111) single-crystal surface after exposure to O2 at high temperature and at atmospheric pressure. The activated formation of a strongly bound surface layer has been observed, as identified by an asymmetry of the Ag 3d5/2 core-level peak at 367.3 eV and an O 1s peak at 529.0 eV (Oγ). In addition, oxygen was found to be dissolved in the bulk (Oβ), exhibiting an O 1s binding energy between 531 and 530 eV depending on its abundance. X-ray-excited oxygen KVV Auger electron spectroscopy revealed the presence of Oγ by additional peaks at 514.8 and 494.7 eV. UPS displayed oxygen-derived bands located above the emission from the Ag 4d band at 3.2 and 2.5 eV. Oxygen-related peaks below the Ag 4d band were identified as resulting from OH groups formed by reaction of surface oxygen (Oα) with residual hydrogen. The incorporated oxygen caused a pronounced charge separation as reflected by a 1 eV increase in the work function. ISS measurements revealed that Oγ is incorporated in the topmost surface layer, shielding underlying Ag atoms from the He+ beam. All spectroscopic data point to the presence of one monolayer of silver-embedded oxygen, which is in dynamic equilibrium with surface atomic oxygen segregated from the bulk at high temperature. The oxygen embedded in the topmost silver layer is strongly bound to the metal, with its interaction being different from adsorbed atomic oxygen and bulk Ag2O. It is stable up to 900 K, in contrast to the binary silver oxides, and relevant for high-temperature oxidation reactions catalyzed by Ag. A qualitative analysis is presented of the chemical bonding of the different surface species in comparison to the situation of a complex silver oxide reference
Nouveauté or Cliché? Assessment on island ecological vulnerability to Tourism: Application to Zhoushan, China
In comparison with coastal zones, islands are even more vulnerable to anthropogenic disturbance, especially to tourism and tourism-induced activities. Despite a great number of studies on either island tourism or island vulnerability reviewed in this paper, knowledge and practice of the impact from tourism upon island ecological vulnerability (IEV) still needs to be expanded. In this contribution, the IEV of four administrative regions in Zhoushan, China is assessed between 2012 and 2017 based on an “exposure (E)-sensitivity (S)-adaptive capacity (A)” framework and by means of coupling coordination degree modeling (CCDM) for determination of the overall development level of E-S-A subsystems in each region. The assessment results show that: (1) An index system consisting of 1 objective, 3 sub-objectives, 7 elements, and 20 indicators can be established and tested to reflect the IEV to tourism; (2) As the most attractive tourist destinations, Shengsi and Putuo inevitably have the highest IEV values; (3) Dinghai's moderate low level of IEV comes as a surprise, due to its direct connectivity to its neighboring coastal city of Ningbo; (4) The more balanced the coupling coordination degree (CCD) values among E-S-A subsystems are, the higher the IEV values in the four tourist destinations of Zhoushan. In conclusion, tourism can be a double-edged sword for islands, the overall benefits of which outweigh the negative impacts upon island ecological conditions
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