9,071 research outputs found
Influence of water temperature on the efficacy of diquat and endothall versus curlyleaf pondweed
determine the impact of water temperature on the efficacy
of the contact herbicides diquat (6,7-dihydrodipyrido [1,2-
α:2â,1â-c] pyrazinediium ion) and endothall (7-oxabicyclo
[2.2.1] heptane-2,3-dicarboxylic acid) for control of the exotic
nuisance species curlyleaf pondweed (Potamogeton crispus L.)
across a range of water temperatures
Incomplete Transition Complexity of Basic Operations on Finite Languages
The state complexity of basic operations on finite languages (considering
complete DFAs) has been in studied the literature. In this paper we study the
incomplete (deterministic) state and transition complexity on finite languages
of boolean operations, concatenation, star, and reversal. For all operations we
give tight upper bounds for both description measures. We correct the published
state complexity of concatenation for complete DFAs and provide a tight upper
bound for the case when the right automaton is larger than the left one. For
all binary operations the tightness is proved using family languages with a
variable alphabet size. In general the operational complexities depend not only
on the complexities of the operands but also on other refined measures.Comment: 13 page
Norm Optimal Iterative Learning Control with Application to Problems in Accelerator based Free Electron Lasers and Rehabilitation Robotics
This paper gives an overview of the theoretical basis of the norm optimal approach to iterative learning control followed by results that describe more recent work which has experimentally benchmarking the performance that can be achieved. The remainder of then paper then describes its actual application to a physical process and a very novel application in stroke rehabilitation
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Decadal trends in the diurnal variation of galactic cosmic rays observed using neutron monitor data
The diurnal variation (DV) in galactic cosmic ray (GCR) flux is a widely observed phenomenon in neutron monitor data. The background variation considered primarily in this study is due to the balance between the convection of energetic particles away from the Sun and the inward diffusion of energetic particles along magnetic field lines. However, there are also times of enhanced DV following geomagnetic disturbances caused by coronal mass ejections or corotating interaction regions. In this study we investigate changes in the DV over four solar cycles using ground-based neutron monitors at different magnetic latitudes and longitudes at Earth. We divide all of the hourly neutron monitor data into magnetic polarity cycles to investigate cycle-to-cycle variations in the phase and amplitude of the DV. The results show, in general, a similarity between each of the AâŻâŻ0 cycles, but with a phase change between the two. To investigate this further, we split the neutron monitor data by solar magnetic polarity between times when the dominant polarity was either directed outward (positive) or inward (negative) at the northern solar pole. We find that the maxima and minima of the DV changes by, typically, 1â2âŻh between the two polarity states for all non-polar neutron monitors. This difference between cycles becomes even larger in amplitude and phase with the removal of periods with enhanced DV caused by solar wind transients. The time difference between polarity cycles is found to vary in a 22-year cycle for both the maximum and minimum times of the DV. The times of the maximum and minimum in the DV do not always vary in the same manner between AâŻ>âŻ0 and AâŻâŻ0 cycles. In most cases the change in timing of the maximum /minimum is greatest with the stations' geomagnetic cut-off rigidity shows little variation in the DV phase with latitude. We conclude that the change in the DV with the dominant solar polar polarity is not as simple as a phase change, but rather an asymmetric variation which is sensitive to the neutron monitor's asymptotic viewing direction
The impact of new neutrino DIS and Drell-Yan data on large-x parton distributions
New data sets have recently become available for neutrino and antineutrino
deep inelastic scattering on nuclear targets and for inclusive dimuon
production in pp pd interactions. These data sets are sensitive to different
combinations of parton distribution functions in the large-x region and,
therefore, provide different constraints when incorporated into global parton
distribution function fits. We compare and contrast the effects of these new
data on parton distribution fits, with special emphasis on the effects at large
x. The effects of the use of nuclear targets in the neutrino and antineutrino
data sets are also investigated.Comment: 24 pages, 13 figure
The dawn phenomenon in type 2 diabetes: How to assess it in clinical practice?
International audienceAIM : The study was aimed at determining whether the dawn phenomenon in type 2 diabetes (T2D) can be predicted and quantified using simple and easily accessible glucose determinations.METHODS : A total of 210 non-insulin-treated persons with T2D underwent continuous glucose monitoring (CGM). The dawn phenomenon was quantified as the absolute increment from the nocturnal glucose nadir to the pre-breakfast value (Îdawn, mg/dL). Pre-lunch (preL) and pre-dinner (preD) glucose, and their averaged values (preLD), were compared with the nocturnal nadir. These pre-meal values were subtracted from the pre-breakfast values. The differences obtained (Îpre-mealL, Îpre-meal D and Îpre-meal LD) were correlated with Îdawn values. The receiver operating characteristic (ROC) curve was used to select the optimal Îpre-meal value that best predicted a dawn phenomenon, set at a threshold of 20mg/dL.RESULTS : All pre-meal glucose levels and differences from pre-breakfast values (Îpre-meal) significantly correlated (P<0.0001) with the nocturnal nadir and Îdawn values, respectively. The strongest correlations were observed for the parameters averaged at preL and preD time points: r=0.83 for preLD and r=0.58 for Îpre-meal LD. ROC curve analysis indicated that the dawn phenomenon at a threshold of 20mg/dL can be significantly predicted by a Îpre-meal LD cut off value of 10mg/dL. The relationship between Îdawn (Y, mg/dL) and Îpre-meal LD (X, mg/dL) was Y=0.49 X+15.CONCLUSION : The self-monitoring of preprandial glucose values at the three main mealtimes can predict the presence/absence of the dawn phenomenon, and permits reliable assessment of its magnitude without requiring continuous overnight glucose monitoring
Analysis of physical-chemical processes governing SSME internal fluid flows
The efforts to adapt CHAM's computational fluid dynamics code, PHOENICS, to the analysis of flow within the high pressure fuel turbopump (HPFTP) aft-platform seal cavity of the SSME are summarized. In particular, the special purpose PHOENICS satellite and ground station specifically formulated for this application are listed and described, and the preliminary results of the first part two-dimensional analyses are presented and discussed. Planned three-dimensional analyses are also briefly outlined. To further understand the mixing and combustion processes in the SSME fuelside preburners, a single oxygen-hydrogen jet element was investigated
Integrated assessment of oyster reef ecosystem services: Quantifying Denitrification Rates and Nutrient Fluxes
Measurements of nutrient exchange were made in restored oyster reefs and creek sediments in 2014 and 2015 in Harris Creek, Maryland, USA. Rates of ammonium, nitrate and di-nitrogen fluxes were much higher in reef environments than in sediments, and rates of oxygen uptake reflected high inputs of biodeposits. The rate of denitrification was related to oyster biomass and oyster numbers. The shallow nature of the restoration allows light to reach the bottom and benthic microalgal photosynthesis affects the net nutrient exchange with the bottom. After several years, oyster restoration has increased denitrification in Harris Creek, though observations in mature upper Choptank restored reefs are higher. The trajectory of increase of the nutrient ecosystem services is positive and will be followed over time
The Assessment of Commercial Fishing Effort in Virginia Annual Report 1990
The Virginia Institute of Marine Science (VIMS), through funding by the Virginia Marine Resources Commission (VMRC), has conducted an assessment of commercial fishing effort in Virginia\u27s major rivers and Chesapeake Bay beginning in late 1985 to the present, except for brief intervals when funding was unavailable.
This report primarily summarizes the final year of assessment, from 1 October 1989 through 30 September 1990. Objectives of the study were: -1) to assess pound net fishing effort in Chesapeake Bay, in the James, York, Rappahannock, and Potomac rivers, and the Virginia tributaries to the Potomac River; and, 2) to assess stake, anchor and drift gill net fishing effort in the three major Virginia river systems. In the course of our data collection for the James, York and Rappahannock rivers, we have also obtained incidental effort data for these rivers and other areas in the Bay. Fyke net, haul seine and gill net fisheries data are included in this report
The Assessment of Commercial Fishing Effort in Virginia Annual Report 1989
This report summarizes an assessment of commercial fishing effort in the Chesapeake Bay and its Virginia tributaries during the period 1 October 1988 through 30 June 1989. Objectives of the study were: 1) to assess pound net fishing effort in Chesapeake Bay, in the James, York, Rappahannock, and Potomac rivers, and the Virginia tributaries to the Potomac River; and 2) to assess stake, anchor and drift gill net fishing effort in the James, York and Rappahannock rivers.
The study period began on 1 October 1988 and ended on 30 June 1989. Data for fyke net, haul seine and mullet net fisheries, when available, have also been included
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