Hydrogen reliquifier Quarterly report, 27 Sept. - 26 Dec. 1967

Computer analyzed hydrogen reliquefier cycles for selection of optimal cycle, rates, and heat exchanger

Components of multifractality in the Central England Temperature anomaly series

We study the multifractal nature of the Central England Temperature (CET) anomaly, a time series that spans more than 200 years. The series is analyzed as a complete data set and considering a sliding window of 11 years. In both cases, we quantify the broadness of the multifractal spectrum as well as its components defined by the deviations from the Gaussian distribution and the influence of the dependence between measurements. The results show that the chief contribution to the multifractal structure comes from the dynamical dependencies, mainly the weak ones, followed by a residual contribution of the deviations from Gaussianity. However, using the sliding window, we verify that the spikes in the non-Gaussian contribution occur at very close dates associated with climate changes determined in previous works by component analysis methods. Moreover, the strong non-Gaussian contribution found in the multifractal measures from the 1960s onwards is in agreement with global results very recently proposed in the literature.Comment: 21 pages, 10 figure

Hawaiian Dreams : Melodie Waltz

https://digitalcommons.library.umaine.edu/mmb-ps/1052/thumbnail.jp

Assessment of sub-Nyquist deterministic and random data sampling techniques for operational modal analysis

This paper assesses numerically the potential of two different spectral estimation approaches supporting non-uniform in time data sampling at sub-Nyquist average rates (i.e., below the Nyquist frequency) to reduce data transmission payloads in wireless sensor networks (WSNs) for operational modal analysis (OMA) of civil engineering structures. This consideration relaxes transmission bandwidth constraints in WSNs and prolongs sensor battery life since wireless transmission is the most energy-hungry on-sensor operation. Both the approaches assume acquisition of sub-Nyquist structural response acceleration measurements and transmission to a base station without on-sensor processing. The response acceleration power spectral density matrix is estimated directly from the sub-Nyquist measurements and structural mode shapes are extracted using the frequency domain decomposition algorithm. The first approach relies on the compressive sensing (CS) theory to treat sub-Nyquist randomly sampled data assuming that the acceleration signals are sparse/compressible in the frequency domain (i.e., have a small number of Fourier coefficients with significant magnitude). The second approach is based on a power spectrum blind sampling (PSBS) technique considering periodic deterministic sub-Nyquist “multi-coset” sampling and treating the acceleration signals as wide-sense stationary stochastic processes without posing any sparsity conditions. The modal assurance criterion (MAC) is adopted to quantify the quality of mode shapes derived by the two approaches at different sub-Nyquist compression rates (CRs) using computer-generated signals of different sparsity and field-recorded stationary data pertaining to an overpass in Zurich, Switzerland. It is shown that for a given CR, the performance of the CS-based approach is detrimentally affected by signal sparsity, while the PSBS-based approach achieves MAC>0.96 independently of signal sparsity for CRs as low as 11% the Nyquist rate. It is concluded that the PSBS-based approach reduces effectively data transmission requirements in WSNs for OMA, without being limited by signal sparsity and without requiring a priori assumptions or knowledge of signal sparsity

Hawaiian Dreams

https://digitalcommons.library.umaine.edu/mmb-vp/6028/thumbnail.jp

Roses At Twilight

https://digitalcommons.library.umaine.edu/mmb-vp/6489/thumbnail.jp

Hawaiian Dreams (Melodie Waltz)

1. Where soft breezes blow,Back to those shores I want to go;Carefree sunny isles,Heaven has given you its brightest smilesMount, vale, shore and sea,Dearest of mem\u27ries are to meAnd one browneyed maidWith her heart a yearning for my return. CHORUSMy own dear Island,Where moonlight gleams;Dear old Hawaii,Land of my dreams My own dear Island, Where moonlight gleamsDear old Hawaii, Land of my dreams. 2. Moonlight on the sea,And on the sands of Waikiki;There just you and IStroll \u27neath the tropical blue and starlit skySweet sounds on the breeze;Hear that guitar beneath the treesWhere some lover trueSings a Hula serenade to his love

Extension of SPIS to simulate dust electrostatic charging, transport and contamination of lunar probes

A modification of the Spacecraft Plasma Interaction Software has been undertaken under ESA contract 4000107327/12/NL/AK (SPIS-DUST). The primary goal is to provide mission designers with an engineering tool capable of predicting charged dust behavior in a given plasma environment involving a spacecraft / exploration unit in contact with complex topological features at various locations of the Moon’s surface. The tool also aims at facilitating dust contamination diagnostics for sensitive surfaces such as sensors optics, solar panels, thermal interfaces, etc. In this paper, the new user interface and the new numerical solvers developed in the frame of this project is presented. The pre-processing includes the building of a 3D lunar surface from a topology description (i.e. a point list), an interface to position the spacecraft and a merging interface for the spacecraft elements in contact with the lunar surface. Concerning the physical models, the new solvers have been developed in order to model the physics of the ejection of the dust from the soils, the dusts charging and transport in volume and the dust interaction and contamination of the spacecraft. The post-processing includes the standard outputs of SPIS for the electrostatic computation and the plasma plus dedicated instruments for the diagnosis of the dusts. A set of verification test cases are presented in order to demonstrate the new capabilities of this version of SPIS in realistic conditions

Hawaiian Dream

Illustration of palm treehttps://scholarsjunction.msstate.edu/cht-sheet-music/12584/thumbnail.jp

High Velocity Oxy-Fuel (HVOF) Suspension Spraying of Mullite Coatings

This article is an invited paper selected from presentations at the 2008 International Thermal Spray Conference and has been expanded from the original presentationPeer reviewed: YesNRC publication: Ye