599 research outputs found
Separating the low and high hierachies by oracles
AbstractThe relativized low and high hierarchies within NP are considered. An oracle A is constructed such that the low and high hierarchies relative to A are infinite, and for each k an oracle Ak is constructed such that the low and high hierarchies relative to Ak have exactly k levels
Irradiation study of a fully monolithic HV-CMOS pixel sensor design in AMS 180 nm
High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) based on the 180 nm
HV-CMOS process have been proposed to realize thin, fast and highly integrated
pixel sensors. The MuPix7 prototype, fabricated in the commercial AMS H18
process, features a fully integrated on-chip readout, i.e. hit-digitization,
zero suppression and data serialization. It is the first fully monolithic
HV-CMOS pixel sensor that has been tested for the use in high irradiation
environments like HL-LHC. We present results from laboratory and test beam
measurements of MuPix7 prototypes irradiated with neutrons (up to
) and protons (up to ) and compare the performance with non-irradiated
sensors. Efficiencies well above 90 % at noise rates below 200 Hz per pixel are
measured. A time resolution better than 22 ns is measured for all tested
settings and sensors, even at the highest irradiation fluences. The data
transmission at 1.25 Gbit/s and the on-chip PLL remain fully functional
Links between seawater flooding, soil ammonia oxidiser communities and their response to changes in salinity
Acknowledgements We thank Heather Richmond and Mechthild Bömeke for providing excellent technical assistance. In addition, we thank Jessica Heublein for support with respect to basic soil analyses and Laura Lehtovirta-Morley for useful discussion on cultivation of AO. We also thank Ruth Hartwig-Kruse, Michael Kliesch and the team of the âSchutzstation Wattenmeer Langenessâ for support during sampling. FUNDING This work was financially supported by the Deutsche Forschungsgemeinschaft (DFG) (NA 848/1-1).Peer reviewedPostprin
Divergent drivers of the microbial methane sink in temperate forest and grassland soils
Aerated topsoils are important sinks for atmospheric methane (CH4) via oxidation by CH4âoxidizing bacteria (MOB). However, intensified management of grasslands and forests may reduce the CH4 sink capacity of soils. We investigated the influence of grassland landâuse intensity (150 sites) and forest management type (149 sites) on potential atmospheric CH4 oxidation rates (PMORs) and the abundance and diversity of MOB (with qPCR) in topsoils of three temperate regions in Germany. PMORs measurements in microcosms under defined conditions yielded approximately twice as much CH4 oxidation in forest than in grassland soils. High landâuse intensity of grasslands had a negative effect on PMORs (â40%) in almost all regions and fertilization was the predominant factor of grassland landâuse intensity leading to PMOR reduction by 20%. In contrast, forest management did not affect PMORs in forest soils. Upland soil cluster (USC)âα was the dominant group of MOBs in the forests. In contrast, USCâÎł was absent in more than half of the forest soils but present in almost all grassland soils. USCâα abundance had a direct positive effect on PMOR in forest, while in grasslands USCâα and USCâÎł abundance affected PMOR positively with a more pronounced contribution of USCâÎł than USCâα. Soil bulk density negatively influenced PMOR in both forests and grasslands. We further found that the response of the PMORs to pH, soil texture, soil water holding capacity and organic carbon and nitrogen content differ between temperate forest and grassland soils. pH had no direct effects on PMOR, but indirect ones via the MOB abundances, showing a negative effect on USCâα, and a positive on USCâÎł abundance. We conclude that reduction in grassland landâuse intensity and afforestation has the potential to increase the CH4 sink function of soils and that different parameters determine the microbial methane sink in forest and grassland soils.Deutsche Forschungsgemeinschaft
http://dx.doi.org/10.13039/501100001659ESFMinistry of Education, Science and Culture of MecklenburgâWestern PomeraniaPeer Reviewe
The MuPix Telescope: A Thin, high Rate Tracking Telescope
The MuPix Telescope is a particle tracking telescope, optimized for tracking
low momentum particles and high rates. It is based on the novel High-Voltage
Monolithic Active Pixel Sensors (HV-MAPS), designed for the Mu3e tracking
detector. The telescope represents a first application of the HV-MAPS
technology and also serves as test bed of the Mu3e readout chain. The telescope
consists of up to eight layers of the newest prototypes, the MuPix7 sensors,
which send data self-triggered via fast serial links to FPGAs, where the data
is time-ordered and sent to the PC. A particle hit rate of 1 MHz per layer
could be processed. Online tracking is performed with a subset of the incoming
data. The general concept of the telescope, chip architecture, readout concept
and online reconstruction are described. The performance of the sensor and of
the telescope during test beam measurements are presented.Comment: Proceedings TWEPP 2016, 8 pages, 7 figure
MuPix7 - A fast monolithic HV-CMOS pixel chip for Mu3e
The MuPix7 chip is a monolithic HV-CMOS pixel chip, thinned down to 50 \mu m.
It provides continuous self-triggered, non-shuttered readout at rates up to 30
Mhits/chip of 3x3 mm^2 active area and a pixel size of 103x80 \mu m^2. The hit
efficiency depends on the chosen working point. Settings with a power
consumption of 300 mW/cm^2 allow for a hit efficiency >99.5%. A time resolution
of 14.2 ns (Gaussian sigma) is achieved. Latest results from 2016 test beam
campaigns are shown.Comment: Proceedingsfor the PIXEL2016 conference, submitted to JINST A
dangling reference has been removed from this version, no other change
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