84 research outputs found
Large-Area Silicon Detectors for the Advanced Composition Explorer (ACE) Solar Isotope Spectrometer (SIS)
Extensive measurements were made of the thicknesses and dead-layers of the large-area, highpurity silicon detectors used for the Solar Isotope Spectrometer (SIS), an instrument to be launched on the Advanced Composition Explorer (ACE) spacecraft. Tests using accelerated beams of heavy nuclei were also carried out to characterize the completed instrument
The ACE-CRIS Scintillating Optical Fiber Trajectory (SOFT) Detector: Calibrations at the NSCL and GSI
The Scintillating Optical Fiber Trajectory (SOFT) detector, the hodoscope for the Cosmic Ray Isotope Spectrometer (CRIS) on the NASA Advanced Composition Explorer, was calibrated using 155 MeV/n He, Li, C, N, 0, and Ar at the Michigan State University National Superconducting
Cyclotron Laboratory (NSCL), and 200 - 700 MeV/n C, Si, and Fe at the GSI facility in Darrnstadt. Germany. The flight instrument consists of three hodoscope fiber planes and one trigger plane. read out by an image intensified CCD camera system and by intensified photodiodes respectively. The
spatial and angular resolution of the hodoscope is described, along with the detection efficiency of both the hodoscope and trigger plane as a function of charge
The Solar Isotope Spectrometer (SIS)
The Solar Isotope Spectrometer (SIS) is scheduled for launch on NASA's Advanced Composition Explorer (ACE) mission. SIS has two solid-state telescopes that are designed to measure the elemental and isotopic composition of solar energetic particles and anomalous cosmic rays in the energy range from rv 10 to 100 Me V /nucleon, including elements from He to Zn (2≤Z≤30). This paper presents
a brief description of the design and operation of SIS
Impacts of extreme weather on wheat and maize in France: evaluating regional crop simulations against observed data
Extreme weather conditions can strongly affect agricultural production, with negative impacts that can at times be detected at regional scales. In France, crop yields were greatly influenced by drought and heat stress in 2003 and by extremely wet conditions in 2007. Reported regional maize and wheat yields where historically low in 2003; in 2007 wheat yields were lower and maize yields higher than long-term averages. An analysis with a spatial version (10x10 km) of th EPIC crop model was tested with regards to regional crop yield anomalies of wheat and maize resulting from extreme weather events in France in 2003 and 2007, by comparing simulated results against reported regional crops statistics, as well as using remotely sensed soil moisture data. Causal relations between soil moisture and crop yields were specifically analyzed. Remotely sensed (AMSR-E) JJA soil moisture correlated significantly with reported regional crop yield for 2002-2007. The spatial correlation between JJA soil moisture and wheat yield anomalies was positive in dry 2003 and negative in wet 2007. Biweekly soil moisture data correlated positively with wheat yield anomalies from the first half of June until the second half of July in 2003. In 2007, the relation was negative the first half of June until the second half of August. EPIC reproduced observed soil dynamics well, and it reproduced the negative wheat and maize yield anomalies of the 2003 heat wave and drought, as well as the positive maize yield anomalies in wet 2007. However, it did not reproduce the negative wheat yield anomalies due to excessive rains and wetness in 2007. Results indicated that EPIC, in line with other crop models widely used at regional level in climate change studies, is capable of capturing the negative impacts of droughts on crop yields, while it fails to reproduce negative impacts of heavy rain and excessively wet conditions on wheat yield, due to poor representations of critical factors affecting plant growth and management. Given that extreme weather events are expected to increase in frequency and perhaps severity in coming decades, improved model representation of crop damage due to extreme events is warranted in order to better quantify future climate change impacts and inform appropriate adaptation responses
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Do automatic self-associations relate to suicidal ideation?
Dysfunctional self-schemas are assumed to play an important role in suicidal ideation. According to recent information-processing models, it is important to differentiate between 'explicit' beliefs and automatic associations. Explicit beliefs stem from the weighting of propositions and their corresponding 'truth' values, while automatic associations reflect more simple associations in memory. Both types of associations are assumed to have different functional properties and both may be involved in suicidal ideation. Thus far, studies into self-schemas and suicidal ideation focused on the more explicit, consciously accessible traces of self-schemas and predominantly relied on self-report questionnaires or interviews. To complement these 'explicit' findings and more directly tap into self-schemas, this study investigated automatic self-associations in a large scale community sample that was part of the Netherlands Study of Depression and Anxiety (NESDA). The results showed that automatic self-associations of depression and anxiety were indeed significantly related to suicidal ideation and past suicide attempt. Moreover, the interactions between automatic self-depressive (anxious) associations and explicit self-depressive (anxious) beliefs explained additional variance over and above explicit self-beliefs. Together these results provide an initial insight into one explanation of why suicidal patients might report difficulties in preventing and managing suicidal thoughts. © 2009 The Author(s)
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