Soiling Forecasting in Large Grid-Connected PV Plants and experience in Spain

2021 ◽  
Author(s):  
Marta Redondo ◽  
Carlos A. Platero ◽  
Antonio Moset ◽  
Fernando Rodriguez ◽  
Vicente Donate
Keyword(s):  
Large Grid

scholarly journals Neighbors consistently influence growth and survival in a frequently burned savanna

2021 ◽  
Author(s):  
Mark Davis ◽  
Richard Condit
Keyword(s):  
Significant Role ◽  
Spatial Arrangement ◽  
Landscape Dynamics ◽  
Positive Interactions ◽  
Successful Management ◽  
Growth And Survival ◽  
Long Term Studies ◽  
Large Grid

Successful management of savannas is challenging and requires knowledge of the causes and consequences of the spatial arrangement of the trees. In savannas, trees are often aggregated, and the ability of trees within the clumps to survive fires plays a significant role in determining the savannas landscape dynamics. Whether or not a tree survives a fire is often dependent on the nature of their interactions with neighboring trees, positive or negative. In cases where disturbances are episodic, detecting these interactions is only going to be possible through long-term studies. Data reported here, from twenty-five years of annual tree censusing of a large grid-plot in a frequently burned savanna, showed consistent neighbor facilitated survival, irrespective as to whether the neighbors were conspecifics or heterospecifics. The positive interactions likely involve the reduction of both herbaceous and woody fuel in denser sites, and possibly mycorrhizal sharing among nearby trees.

scholarly journals No evidence for intermediate-mass black holes in the globular clusters ω Cen and NGC 6624

2019 ◽  
Vol 488 (4) ◽  
pp. 5340-5351 ◽  
Author(s):  
H Baumgardt ◽  
C He ◽  
S M Sweet ◽  
M Drinkwater ◽  
A Sollima ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Globular Clusters ◽  
Surface Brightness ◽  
Velocity Dispersion ◽  
Stellar Mass ◽  
Main Sequence Stars ◽  
Intermediate Mass ◽  
Measured Velocity ◽  
Large Grid

ABSTRACT We compare the results of a large grid of N-body simulations with the surface brightness and velocity dispersion profiles of the globular clusters ω Cen and NGC 6624. Our models include clusters with varying stellar-mass black hole retention fractions and varying masses of a central intermediate-mass black hole (IMBH). We find that an $\sim 45\, 000$ M⊙ IMBH, whose presence has been suggested based on the measured velocity dispersion profile of ω Cen, predicts the existence of about 20 fast-moving, m > 0.5 M⊙, main-sequence stars with a (1D) velocity v > 60 km s−1 in the central 20 arcsec of ω Cen. However, no such star is present in the HST/ACS proper motion catalogue of Bellini et al. (2017), strongly ruling out the presence of a massive IMBH in the core of ω Cen. Instead, we find that all available data can be fitted by a model that contains 4.6 per cent of the mass of ω Cen in a centrally concentrated cluster of stellar-mass black holes. We show that this mass fraction in stellar-mass BHs is compatible with the predictions of stellar evolution models of massive stars. We also compare our grid of N-body simulations with NGC 6624, a cluster recently claimed to harbour a 20 000 M⊙ black hole based on timing observations of millisecond pulsars. However, we find that models with MIMBH > 1000 M⊙ IMBHs are incompatible with the observed velocity dispersion and surface brightness profile of NGC 6624, ruling out the presence of a massive IMBH in this cluster. Models without an IMBH provide again an excellent fit to NGC 6624.

TACTICAL ROUTE PLANNING: NEW ALGORITHMS FOR DECOMPOSING THE MAP

1996 ◽  
Vol 05 (01n02) ◽  
pp. 199-218 ◽  
Author(s):  
J.R. BENTON ◽  
S.S. IYENGAR ◽  
W. DENG ◽  
N. BRENER ◽  
V.S. SUBRAHMANIAN
Keyword(s):  
Data Structures ◽  
Fundamental Problem ◽  
Route Planning ◽  
Decomposition Methods ◽  
Search Algorithms ◽  
Experimental Results ◽  
New Approach ◽  
Robotic Vehicles ◽  
New Algorithms ◽  
Large Grid

This paper defines a new approach and investigates a fundamental problem in route planners. This capability is important for robotic vehicles(Martian Rovers, etc.) and for planning off-road military maneuvers. The emphasis throughout this paper will be on the design and analysis and hieiaichical implementation of our route planner. This work was motivated by anticipation of the need to search a grid of a trillion points for optimum routes. This cannot be done simply by scaling upward from the algorithms used to search a grid of 10,000 points. Algorithms sufficient for the small grid are totally inadequate for the large grid. Soon, the challenge will be to compute off-road routes more than 100 km long and with a one or two-meter grid. Previous efforts are reviewed and the data structures, decomposition methods and search algorithms are analyzed and limitations are discussed. A detailed discussion of a hieraichical implementation is provided and the experimental results are analyzed.

scholarly journals Theoretical red-giant branches for globular clusters

1984 ◽  
Vol 105 ◽  
pp. 143-146
Author(s):  
Don A. VandenBerg
Keyword(s):  
Boundary Conditions ◽  
Globular Clusters ◽  
Main Sequence ◽  
Surface Boundary ◽  
Los Alamos ◽  
Surface Boundary Conditions ◽  
Stellar Models ◽  
Red Giant ◽  
Large Grid

VandenBerg (1983a; hereinafter V) has recently computed a large grid of stellar evolutionary sequences from the zero-age main sequence to the base of the red-giant branch (RGB) and carried out extensive comparisons of the associated isochrones with published photometry of globular clusters (GCs). These calculations were based on the latest Los Alamos opacities and, in addition, made use of available model atmospheres for improved surface boundary conditions as well as for the transformation of the stellar models from the (Mbol, log Teff)-to the (Mv, B-V)-plane. In general, very encouraging agreement of the predicted and observed morphologies of cluster C-M diagrams was obtained.

scholarly journals Ionization correction factors for sodium, potassium, and calcium in planetary nebulae

2019 ◽  
Vol 492 (1) ◽  
pp. 950-965
Author(s):  
A Amayo ◽  
G Delgado-Inglada ◽  
J García-Rojas
Keyword(s):  
Planetary Nebulae ◽  
Emission Lines ◽  
Condensation Temperature ◽  
Correction Factors ◽  
Dust Grains ◽  
Degree Of Ionization ◽  
Sodium Potassium ◽  
First Time ◽  
Analytical Expressions ◽  
Large Grid

ABSTRACT We use a large grid of photoionization models that are representative of observed planetary nebulae (PNe) to derive ionization correction factors (ICFs) for sodium, potassium, and calcium. In addition to the analytical expressions of the ICFs, we provide the range of validity where the ICFs can be safely used and an estimate of the typical uncertainties associated with the ICFs. We improved the previous ICFs for calcium and potassium in the literature and suggest for the first time an ICF for sodium. We tested our ICFs with a sample of 39 PNe with emission lines of some ion of these elements. No obvious trend is found between the derived abundances and the degree of ionization, suggesting that our ICFs do not seem to be introducing an artificial bias in the results. The abundances found in the studied PNe range from $-2.88_{-0.22}^{+0.21}$ to −2.09 ± 0.21 in log (Na/O), from $-4.20_{-0.45}^{+0.31}$ to $-3.05_{-0.47}^{+0.26}$ in log (K/O), and from $-3.71_{-0.34}^{+0.41}$ to $-1.57_{-0.47}^{+0.33}$ in log (Ca/O). These numbers imply that some of the studied PNe have up to ∼65 per cent, 75 per cent, or 95 per cent of their Na, K, and/or Ca atoms condensed into dust grains, respectively. As expected, the highest depletions are found for calcium which is the element with the highest condensation temperature.

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