scholarly journals The Emirates Mars Ultraviolet Spectrometer (EMUS) for the EMM Mission

2021 ◽  
Vol 217 (8) ◽  
Author(s):  
Gregory M. Holsclaw ◽  
Justin Deighan ◽  
Hessa Almatroushi ◽  
Mike Chaffin ◽  
John Correira ◽  
...  
Keyword(s):  
Global Climate ◽  
Focal Length ◽  
Photon Counting ◽  
Average Power ◽  
High Sensitivity ◽  
Cesium Iodide ◽  
Optical Channel ◽  
Linear Dispersion ◽  
Mars Atmosphere ◽  
Ultraviolet Spectrometer

AbstractThe Emirates Mars Mission (EMM) Hope probe was launched on 20 July 2020 at 01:58 GST (Gulf Standard Time) and entered orbit around Mars on 9 Feb 2021 at 19:42 GST. The high-altitude orbit (19,970 km periapse, 42,650 km apoapse altitude, 25° inclination) with a 54.5 hour period enables a unique, synoptic, and nearly-continuous monitor of the Mars global climate. The Emirates Mars Ultraviolet Spectrometer (EMUS), one of three remote sensing instruments carried by Hope, is an imaging ultraviolet spectrograph, designed to investigate how conditions throughout the Mars atmosphere affect rates of atmospheric escape, and how key constituents in the exosphere behave temporally and spatially. EMUS will target two broad regions of the Mars upper atmosphere: 1) the thermosphere (100–200 km altitude), observing UV dayglow emissions from hydrogen (102.6, 121.6 nm), oxygen (130.4, 135.6 nm), and carbon monoxide (140–170 nm) and 2) the exosphere (above 200 km altitude), observing bound and escaping hydrogen (121.6 nm) and oxygen (130.4 nm).EMUS achieves high sensitivity across a wavelength range of 100–170 nm in a single optical channel by employing “area-division” or “split” coatings of silicon carbide (SiC) and aluminum magnesium fluoride (Al+MgF2) on each of its two optical elements. The EMUS detector consists of an open-face (windowless) microchannel plate (MCP) stack with a cesium iodide (CsI) photocathode and a photon-counting, cross-delay line (XDL) anode that enables spectral-spatial imaging. A single spherical telescope mirror with a 150 mm focal length provides a 10.75° field of view along two science entrance slits, selectable with a rotational mechanism. The high and low resolution (HR, LR) slits have angular widths of 0.18° and 0.25° and spectral widths of 1.3 nm and 1.8 nm, respectively. The spectrograph uses a Rowland circle design, with a toroidally-figured diffraction grating with a laminar groove profile and a ruling density of 936 gr mm−1 providing a reciprocal linear dispersion of 2.65 nm mm−1. The total instrument mass is 22.3 kg, and the orbit-average power is less than 15 W.

scholarly journals Enhanced chemiluminescence: a high-sensitivity detection system for in situ hybridization and immunohistochemistry.

1993 ◽  
Vol 41 (11) ◽  
pp. 1591-1597 ◽  
Author(s):  
P Lorimier ◽  
L Lamarcq ◽  
F Labat-Moleur ◽  
C Guillermet ◽  
R Bethier ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Detection System ◽  
Photon Counting ◽  
Protein Detection ◽  
High Sensitivity ◽  
Papilloma Virus ◽  
Enhanced Chemiluminescence ◽  
Discriminatory Analysis ◽  
High Sensitivity Detection

The breakthrough of chemiluminescence in the field of solution immunoassays and transfer membranes prompted us to explore whether a light-based detection system could provide a gain in sensitivity over chromogenic and FITC markers for nucleic acid and protein detection on histological preparations. A Hamamatsu device and an enhanced chemiluminescence (ECL) luminol substrate of the peroxidase were used to detect epithelial and endothelial components by immunohistochemistry (IHC) and for in situ hybridization (ISH) of papilloma virus DNA. The accuracy of the signal was compared to that obtained with DAB-peroxidase, silver-enhanced DAB-peroxidase, NBT-BCIP-alkaline phosphatase, and FITC. Our results demonstrated the feasibility and high sensitivity of luminescence detection for histological preparations. In part due to the ultrasensitive videocamera and photon-counting imaging, interpretable and reproducible results were obtained within counting times shorter than 5 min, and with dilutions of the primary antibodies 100- to 10,000-fold greater than those used for chromogenic and FITC reactions. As for ISH, with identical concentrations of the HPV 18 DNA probe on HeLa cells, labeling was apparent by luminescence but undetectable with the chromogen. The morphological resolution allowed a discriminatory analysis of the signal. Therefore, at the light microscopic level, enhanced chemiluminescence offers an appealing alternative to FITC and chromogenic markers for detection and quantification of low-concentration molecules.

High-sensitivity photon-counting imaging detector

2005 ◽  
Author(s):  
Lichen Fu ◽  
Ye Li ◽  
Qingduo Duanmu ◽  
Guozheng Wang ◽  
Kui Wu ◽  
...  
Keyword(s):  
Photon Counting ◽  
High Sensitivity ◽  
Imaging Detector

scholarly journals Sulphur-rich volcanic eruptions triggered extreme hydrological events in Europe since AD 1850

2016 ◽  
Author(s):  
Cristina Di Salvo ◽  
Gianluca Sottili
Keyword(s):  
North Atlantic ◽  
River Flow ◽  
Hydrological Cycle ◽  
Global Climate ◽  
Cloud Condensation Nuclei ◽  
Substantial Reduction ◽  
Hydrological Regime ◽  
High Sensitivity ◽  
Volcanic Eruptions ◽  
Anthropogenic Aerosols

Abstract. Volcanic and anthropogenic aerosols, by reflecting solar radiation and acting as cloud condensation nuclei, play a key role in the global climate system. Given the contrasting microphysical and radiative effects of SO2 on rainfall amounts and intensities, the combined effects of these two factors are still poorly understood. Here, we show how concentrations of volcanic sulphate aerosols in the atmosphere, as derived from Greenland ice core records, are strictly correlated with dramatic variations of hydrological cycle in Europe. Specifically, since the second half of the 19th century, the intensity of extreme precipitations in Western Europe, and associated river flood events, changed significantly during the 12–24 months following sulphur-rich eruptions. During the same period, volcanic SO2 exerts divergent effects in central and Northern Europe, where river flow regimes are affected, in turn, by the substantial reduction of rainfall intensity and earlier occurrences of ice break-up events. We found that the high sensitivity of North Atlantic Sea Surface Temperature (SST) and North Atlantic Oscillation (NAO) to atmospheric SO2 concentrations reveals a complex mechanism of interaction between sulphur-rich eruptions and heat exchange between Ocean and atmosphere with substantial impacts on hydrological regime in Europe.

scholarly journals Characterization and performance evaluation of the XSPA-500k detector using synchrotron radiation

2021 ◽  
Vol 28 (2) ◽  
pp. 439-447
Author(s):  
Yasukazu Nakaye ◽  
Takuto Sakumura ◽  
Yasutaka Sakuma ◽  
Satoshi Mikusu ◽  
Arkadiusz Dawiec ◽  
...  
Keyword(s):  
High Performance ◽  
Performance Metrics ◽  
Dynamic Range ◽  
Photon Counting ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Frame Rate ◽  
X Rays ◽  
Response Modulation ◽  
Modulation Transfer

Hybrid photon counting (HPC) detectors are widely used at both synchrotron facilities and in-house laboratories. The features of HPC detectors, such as no readout noise, high dynamic range, high frame rate, excellent point spread function, no blurring etc. along with fast data acquisition, provide a high-performance detector with a low detection limit and high sensitivity. Several HPC detector systems have been developed around the world. A number of them are commercially available and used in academia and industry. One of the important features of an HPC detector is a fast readout speed. Most HPC detectors can easily achieve over 1000 frames s−1, one or two orders of magnitude faster than conventional CCD detectors. Nevertheless, advanced scientific challenges require ever faster detectors in order to study dynamical phenomena in matter. The XSPA-500k detector can achieve 56 kframes s−1 continuously, without dead-time between frames. Using `burst mode', a special mode of the UFXC32k ASIC, the frame rate reaches 1 000 000 frames s−1. XSPA-500k was fully evaluated at the Metrology beamline at Synchrotron SOLEIL (France) and its readout speed was confirmed by tracking the synchrotron bunch time structure. The uniformity of response, modulation transfer function, linearity, energy resolution and other performance metrics were also verified either with fluorescence X-rays illuminating the full area of the detector or with the direct beam.

scholarly journals Flexible and Highly Sensitive Strain Sensor Based on Laser-Induced Graphene Pattern Fabricated by 355 nm Pulsed Laser

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4867 ◽  
Author(s):  
Sung-Yeob Jeong ◽  
Yong-Won MA ◽  
Jun-Uk Lee ◽  
Gyeong-Ju Je ◽  
Bo-sung Shin
Keyword(s):  
Focal Length ◽  
Pulsed Laser ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Gauge Factor ◽  
Functional Evaluation ◽  
Mechanical Fracture ◽  
Highly Sensitive ◽  
Human Finger ◽  
Small Deformations

A laser-induced-graphene (LIG) pattern fabricated using a 355 nm pulsed laser was applied to a strain sensor. Structural analysis and functional evaluation of the LIG strain sensor were performed by Raman spectroscopy, scanning electron microscopy (SEM) imaging, and electrical–mechanical coupled testing. The electrical characteristics of the sensor with respect to laser fluence and focal length were evaluated. The sensor responded sensitively to small deformations, had a high gauge factor of ~160, and underwent mechanical fracture at 30% tensile strain. In addition, we have applied the LIG sensor, which has high sensitivity, a simple manufacturing process, and good durability, to human finger motion monitoring.

scholarly journals Integrating within-species variation in thermal physiology into climate change ecology

2019 ◽  
Vol 374 (1778) ◽  
pp. 20180550 ◽  
Author(s):  
Scott Bennett ◽  
Carlos M. Duarte ◽  
Núria Marbà ◽  
Thomas Wernberg
Keyword(s):  
Climate Change ◽  
Global Climate ◽  
Thermal Sensitivity ◽  
High Sensitivity ◽  
Population Level ◽  
Marine Organisms ◽  
Ocean Warming ◽  
Species Variation ◽  
Thermal Physiology ◽  
Physiological Diversity

Accurately forecasting the response of global biota to warming is a fundamental challenge for ecology in the Anthropocene. Within-species variation in thermal sensitivity, caused by phenotypic plasticity and local adaptation of thermal limits, is often overlooked in assessments of species responses to warming. Despite this, implicit assumptions of thermal niche conservatism or adaptation and plasticity at the species level permeate the literature with potentially important implications for predictions of warming impacts at the population level. Here we review how these attributes interact with the spatial and temporal context of ocean warming to influence the vulnerability of marine organisms. We identify a broad spectrum of thermal sensitivities among marine organisms, particularly in central and cool-edge populations of species distributions. These are characterized by generally low sensitivity in organisms with conserved thermal niches, to high sensitivity for organisms with locally adapted thermal niches. Important differences in thermal sensitivity among marine taxa suggest that warming could adversely affect benthic primary producers sooner than less vulnerable higher trophic groups. Embracing the spatial, temporal and biological context of within-species variation in thermal physiology helps explain observed impacts of ocean warming and can improve forecasts of climate change vulnerability in marine systems. This article is part of the theme issue ‘Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen’.

ISMIP6-based projections of ocean-forced Antarctic ice loss using the Community Ice Sheet Model 

2021 ◽  
Author(s):  
William Lipscomb ◽  
Gunter Leguy ◽  
Nicolas Jourdain ◽  
Xylar Asay-Davis ◽  
Hélène Seroussi ◽  
...  
Keyword(s):  
Sea Level ◽  
Climate Models ◽  
Global Climate ◽  
Ice Sheet ◽  
High Sensitivity ◽  
Global Climate Models ◽  
Thermal Forcing ◽  
Antarctic Ice Sheet ◽  
Basal Friction ◽  
West Antarctic

<p>The future retreat rate for marine-based regions of the Antarctic Ice Sheet is one of the largest uncertainties in sea-level projections. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) aims to improve projections and quantify uncertainties by running an ensemble of ice sheet models with forcing derived from global climate models. Here, the Community Ice Sheet Model (CISM) is used to run ISMIP6-based projections of ocean-forced Antarctic Ice Sheet evolution. Using several combinations of sub-ice-shelf melt schemes, CISM is spun up to steady state over many millennia. During the spin-up, basal-friction and thermal-forcing parameters are adjusted to optimize agreement with the observed ice thickness. The model is then run forward to year 2500, applying ocean thermal forcing anomalies from six climate models. In all simulations, ocean warming triggers long-term retreat of the West Antarctic Ice Sheet, especially in the Filchner-Ronne and Ross sectors. The ocean-forced sea-level rise in 2500 varies from about 150 mm to 1300 mm, depending on the melt scheme and ocean forcing applied. Further experiments show relatively high sensitivity to the basal friction law, and moderate sensitivity to grid resolution and the prescribed collapse of small ice shelves. The Amundsen sector exhibits threshold behavior, with modest retreat under many parameter settings, but complete collapse under some combinations of low basal friction and high thermal-forcing anomalies. Large uncertainties remain, as a result of parameterized sub-shelf melt rates, simplified treatments of calving and basal friction, and the lack of ice–ocean coupling.</p>

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