665 research outputs found

    Koenikea-species (Acari, Hydrachnellae) from the Amazon region

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    20 Arten des Genus Koenikea (Acari, Hydrachnellae) werden aus Amazonien beschrieben, von denen 1 bereits bekannt, 12 neu für die Wissenschaft sind. Das Material wurde von H. Sioli 1952 gesammelt. Die übrigen Wassermilben-Arten wurden bereits von VIETS (1959) veröffentlicht

    Flip-flop jet nozzle extended to supersonic flows

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76991/1/AIAA-11725-757.pd

    Reconstructing the calibrated strain signal in the Advanced LIGO detectors

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    Advanced LIGO's raw detector output needs to be calibrated to compute dimensionless strain h(t). Calibrated strain data is produced in the time domain using both a low-latency, online procedure and a high-latency, offline procedure. The low-latency h(t) data stream is produced in two stages, the first of which is performed on the same computers that operate the detector's feedback control system. This stage, referred to as the front-end calibration, uses infinite impulse response (IIR) filtering and performs all operations at a 16384 Hz digital sampling rate. Due to several limitations, this procedure currently introduces certain systematic errors in the calibrated strain data, motivating the second stage of the low-latency procedure, known as the low-latency gstlal calibration pipeline. The gstlal calibration pipeline uses finite impulse response (FIR) filtering to apply corrections to the output of the front-end calibration. It applies time-dependent correction factors to the sensing and actuation components of the calibrated strain to reduce systematic errors. The gstlal calibration pipeline is also used in high latency to recalibrate the data, which is necessary due mainly to online dropouts in the calibrated data and identified improvements to the calibration models or filters.Comment: 20 pages including appendices and bibliography. 11 Figures. 3 Table

    Кераміка для техніки

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    The benthic invertebrates fauna of most of the saline lakes of the Sud Lipez region (Bolivia, Altiplano) has been until now quite unstudied. Samples collected during an extensive survey of 12 lakes and two small inflow rivers allow a first list of the main macroinvertebrates living in the biotopes. The heterogeneous nature of these saline lakes with their freshwater springs and phreatic inflows offers a variety of habitats to macroinvertebrates. The benthic fauna in lakes with salinity > 10 g l-1 is not so low in density but includes few species and is dominated by Orthocladinae and Podonominae larvae. In contrast, the freshwater springs and inflows are colonized by a diverse fauna with a mixture of both freshwater and saline taxa, but dominated by Elmidae and Amphipoda. The lakes are quite isolated and, apart from some cosmopolitan organisms, their fauna can be quite distinctive. (Résumé d'auteur

    Life cycle assessment of local and crossbred cattle production systems in Central Java, Indonesia

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    Indonesia is a prominent example where crossbreeding with European breeds has been promoted to intensify beef production. It is implemented throughout the country regardless of the different agro-ecological conditions, of which the available feed resources are the main element. Crossbreeding at farm level in Central Java showed that crossbreeding has not changed the farming systems or motivations for keeping cattle. These results lead to our hypothesis that we expect no differences in global warming potential (GWP) of local and crossbred cattle production systems in Central Java. Life Cycle Assessment (LCA) is acknowledged method to assess the contribution of livestock production to GWP. Expressed per kg live weight, GWP of local and crossbred cattle was 29.1 kg CO2 and 32.1 kg CO2. These results were higher compared to the GWP of beef cattle production systems in European countries. Future LCA’s of smallholder systems should pay more attention to the multi-functional aspects of a production system, because the GWP’s mitigation depending on the multi-functions included

    Metric Assisted Stochastic Sampling (MASS) search for gravitational waves from binary black hole mergers

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    We present a novel gravitational wave detection algorithm that conducts amatched filter search stochastically across the compact binary parameter spacerather than relying on a fixed bank of template waveforms. This technique iscompetitive with standard template-bank-driven pipelines in both computationalcost and sensitivity. However, the complexity of the analysis is simplerallowing for easy configuration and horizontal scaling across heterogeneousgrids of computers. To demonstrate the method we analyze approximately onemonth of public LIGO data from July 27 00:00 2017 UTC - Aug 25 22:00 2017 UTCand recover eight known confident gravitational wave candidates. We also injectsimulated binary black hole (BBH) signals to demonstrate the sensitivity.<br

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

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    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

    Characterization of systematic error in Advanced LIGO calibration

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    The raw outputs of the detectors within the Advanced Laser Interferometer Gravitational-Wave Observatory need to be calibrated in order to produce the estimate of the dimensionless strain used for astrophysical analyses. The two detectors have been upgraded since the second observing run and finished the year-long third observing run. Understanding, accounting, and/or compensating for the complex-valued response of each part of the upgraded detectors improves the overall accuracy of the estimated detector response to gravitational waves. We describe improved understanding and methods used to quantify the response of each detector, with a dedicated effort to define all places where systematic error plays a role. We use the detectors as they stand in the first half (six months) of the third observing run to demonstrate how each identified systematic error impacts the estimated strain and constrain the statistical uncertainty therein. For this time period, we estimate the upper limit on systematic error and associated uncertainty to be <7%< 7\% in magnitude and <4< 4 deg in phase (68%68\% confidence interval) in the most sensitive frequency band 20-2000 Hz. The systematic error alone is estimated at levels of <2%< 2\% in magnitude and <2< 2 deg in phase
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