Correction to: Calibration of Genetic Algorithm Parameters for Mining-Related Optimization Problems     

Villalba Matamoros  Martha E.  Kumral  Mustafa 《Natural Resources Research》2019,28(2):457-459

Natural Resources Research - The original version of this article unfortunately contained a mistake in figures. The source file for figures was submitted and published incorrectly; hence, the...  相似文献   

Fisheries traffic: The poor relation of port devolution. Lessons from Spanish state ports of general interest     

José I. Castillo-Manzano  David Florido-Del-Corral  Lourdes Lopez-Valpuesta 《Marine Policy》2010

The fisheries sector is currently contending with the hectic development of its own political economy framework being convulsed by the dynamics of decentralisation. This process is enshrouded in an environment of economic globalisation, taking place against the backdrop of the governance approach. With this situation as the starting point, the main goal of this paper is to quantify the effects that the Spanish port devolution process might have on the Spanish fisheries sector through the use of a transfer function model; the volumes of landings at State ports of general interest and their cash value are taken as dependent variables.  相似文献   

The thermal reaction of Venezuelan lateritic bauxites with glycerol     

E. Mendelovici  A. Sagarzazu  R. Villalba 《Chemical Geology》1987,60(1-4):177-184

Goethite contained in lateritic bauxites or in artificial mineral admixtures is completely transformed into peculiar Fe-alkoxide compounds by reaction with glycerol at 245°C. Magnetic spinel oxides result from hydrolysis by boiling water of alkoxides obtained from the artificial admixtures. On the other hand, the production of magnetic spinel materials is not observed in alkoxides derived from natural lateritic samples. This may be caused by the high amount of Al substituting for Fe in these Venezuelan lateritic goethites.  相似文献   

Sunspots During the Maunder Minimum from Machina Coelestis by Hevelius     

V. M. S. Carrasco  J. Villalba Álvarez  J. M. Vaquero 《Solar physics》2015,290(10):2719-2732

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The challenge to detect and attribute effects of climate change on human and natural systems     

Dáithí Stone  Maximilian Auffhammer  Mark Carey  Gerrit Hansen  Christian Huggel  Wolfgang Cramer  David Lobell  Ulf Molau  Andrew Solow  Lourdes Tibig  Gary Yohe 《Climatic change》2013,118(2):381-395

Future scenarios of the energy system under greenhouse gas emission constraints depict dramatic growth in a range of energy technologies. Technological growth dynamics observed historically provide a useful comparator for these future trajectories. We find that historical time series data reveal a consistent relationship between how much a technology’s cumulative installed capacity grows, and how long this growth takes. This relationship between extent (how much) and duration (for how long) is consistent across both energy supply and end-use technologies, and both established and emerging technologies. We then develop and test an approach for using this historical relationship to assess technological trajectories in future scenarios. Our approach for “learning from the past” contributes to the assessment and verification of integrated assessment and energy-economic models used to generate quantitative scenarios. Using data on power generation technologies from two such models, we also find a consistent extent - duration relationship across both technologies and scenarios. This relationship describes future low carbon technological growth in the power sector which appears to be conservative relative to what has been evidenced historically. Specifically, future extents of capacity growth are comparatively low given the lengthy time duration of that growth. We treat this finding with caution due to the low number of data points. Yet it remains counter-intuitive given the extremely rapid growth rates of certain low carbon technologies under stringent emission constraints. We explore possible reasons for the apparent scenario conservatism, and find parametric or structural conservatism in the underlying models to be one possible explanation.  相似文献   

Optical Spectroscopy of Comet C/2000 WM1 (LINEAR) at the Guillermo Harro Astrophysical Observatory in Mexico     

Churyumov  Klim I.  Luk'yanyk  Igor V.  Berezhnoi  Alexei A.  Chavushyan  Vahram H.  Sandoval  Lourdes S.  Palma  Alejandro A. 《Earth, Moon, and Planets》2002,90(1-4):361-368

We present a preliminary analysis of medium resolution optical spectra of comet C/2000 WM1 (LINEAR) obtained on 22 November 2001. Theemission lines of the molecules C₂, C₃, CN, NH₂,H₂O⁺ and presumably CO (Asundi and triplet bands) and C₂ ^-were identified in these spectra. By analysing the brightnessdistributions of the C₂, C₃, CN emission lines along theslit of the spectrograph we determined some physical parameters of theseneutrals, such as their lifetimes and expansion velocities inthe coma. The Franck–Condon factors for the CO Asundi bands and C₂ ^- bands were calculated using a Morse potential model.  相似文献   

Creating a Population of 12‐Digit Headwater Basins within the Albemarle‐Pamlico Estuary System     

Mike Cyterski  Lourdes Prieto 《Transactions in GIS》2010,14(5):581-593

Ecological research within the US Environmental Protection Agency's Office of Research and Development has recently changed its focus to quantifying and mapping ecosystem services provided to humans. Our local research group has been charged to develop a regional assessment of several ecosystem services in the Albemarle‐Pamlico Estuary System (APES). Time, data, and funding constraints precluded explicit modeling of the entire APES, so in Phase 1 of our research plan we chose to model ecosystem services in a random sample of headwater catchments. After observing numerous inconsistencies between the National Hydrography Dataset‐Plus (NHDPlus) stream network and the Virginia/North Carolina Watershed Boundary Dataset 12‐digit HUC coverage, we began by creating modified 12‐digit hydrologic units (HUCs) by aggregating smaller catchments delineated within the NHDPlus. In defining our population of interest (headwater 12‐digit HUCs with perennial, natural, wadeable pour points), we generally excluded HUCs that had multiple pour points, no pour points, or whose pour points were intermittent streams, artificial segments, ditches/canals, or lentic systems (lakes and reservoirs). After taking these actions, 318 HUCs remained and a stratified random sample (Omnerik ecoregions as strata) of 50 HUCs was chosen from this population.  相似文献   

Challenging sub terra nullius: a critical underground urbanism project     

Maria de Lourdes Melo Zurita 《The Australian geographer》2020,51(3):269-282

ABSTRACT

Underground urban development is rapidly expanding. Like all forms of ‘development’, utilising the underneath of cities can present a range of possibilities and problems. Much underground urban development, however, has been conceptualised through a technical rather than a broader social lens. This is problematic, not least as these developments are usually financed with public money, while their governance is often realised through complicated and opaque public–private partnerships. In this context, the urban underground is often present as sub terra nullius: an epistemologically blank slate waiting to be exploited with the necessary technology and funding. In this paper, the author presents four analytical strata to help us to rethink how urban undergrounds are conceptualised and developed. Drawing on examples from Australia, she presents how we need to appreciate the more-than-human geographies of the underground (stratum 1); critically understand the dynamics of volumetric dispossession (stratum 2); question who owns the underground and how (stratum 3); and rethink how the underground is accessed (stratum 4). By engaging with these themes, we can explore ways to move subterranean urban development away from a technoscientific tunnelling decision-making process to one that engages with the social, political and economic implications of urban infrastructural projects.  相似文献   

Species and plant community reorganization in the Trans-Mexican Volcanic Belt under climate change conditions     

Lourdes Villers-Ruiz  Diana Castañeda-Aguado 《山地科学学报》2013,10(6):923-931

This study analyzes six vegetation communities in relation to current climatic parameters and eight climate change scenarios along an elevation gradient extending from 2,710 m to 4,210m in the Trans-Mexican Volcanic Belt. The projected movements of 25 plant species with the current restricted or wide altitudinal distributions were also modeled. To relate climatic parameters to the species and communities, a Precipitation/Temperature(P/T)index was used both for the current and the different climate-change scenarios. The temperatures are expected to increase by 1.1°C to 1.7°C by 2020 and by2°C to 3°C by 2050. A decrease of 4% to 13% in the annual precipitation is expected for the 2020 horizon,and a reduction between 3% and 20% is expected for2050. The reductions in water availability were projected for all altitude levels and plant communities.The most marked reduction was under the HADLEYA2 scenario, in which the lower limit of the altitudinal range increased from 2,710 to 3,310 m(2050 horizon)with reductions in the P/T index between 36% and39% compared to the current climate. Most plant species tended to shift their distribution from 200 to300 m upward in the 2020 temporal horizon scenarios. The Pinus hartwegii, Alnus jorullensis and Pinus montezumae communities would have a shorter altitudinal range as they move upward and merge with the remaining species at the higher altitudinal range. For the 2050 temporal horizon,30% of the species, primarily those from the higher altitudinal range, would disappear because their P/Tindex values would be above the limit of plant survival(4,210 m).  相似文献   

Aridity changes in the Temperate-Mediterranean transition of the Andes since ad 1346 reconstructed from tree-rings     

Duncan A. Christie  Jos�� A. Boninsegna  Malcolm K. Cleaveland  Antonio Lara  Carlos Le Quesne  Mariano S. Morales  Manfred Mudelsee  David W. Stahle  Ricardo Villalba 《Climate Dynamics》2011,36(7-8):1505-1521

The Andes Cordillera acts as regional ??Water Towers?? for several countries and encompasses a wide range of ecosystems and climates. Several hydroclimatic changes have been described for portions of the Andes during recent years, including glacier retreat, negative precipitation trends, an elevation rise in the 0° isotherm, and changes in regional streamflow regimes. The Temperate-Mediterranean transition (TMT) zone of the Andes (35.5°?C39.5°S) is particularly at risk to climate change because it is a biodiversity hotspot with heavy human population pressure on water resources. In this paper we utilize a new tree-ring network of Austrocedrus chilensis to reconstruct past variations in regional moisture in the TMT of the Andes by means of the Palmer Drought Severity Index (PDSI). The reconstruction covers the past 657?years and captures interannual to decadal scales of variability in late spring?Cearly summer PDSI. These changes are related to the north?Csouth oscillations in moisture conditions between the Mediterranean and Temperate climates of the Andes as a consequence of the latitudinal position of the storm tracks forced by large-scale circulation modes. Kernel estimation of occurrence rates reveals an unprecedented increment of severe and extreme drought events during the last century in the context of the previous six centuries. Moisture conditions in our study region are linked to tropical and high-latitude ocean-atmospheric forcing, with PDSI positively related to Ni?o-3.4 SST during spring and strongly negatively correlated with the Antarctic Oscillation (AAO) during summer. Geopotential anomaly maps at 500-hPa show that extreme dry years are tightly associated with negative height anomalies in the Ross?CAmundsen Seas, in concordance with the strong negative relationship between PDSI and AAO. The twentieth century increase in extreme drought events in the TMT may not be related to ENSO but to the positive AAO trend during late-spring and summer resulting from a gradual poleward shift of the mid-latitude storm tracks. This first PDSI reconstruction for South America demonstrates the highly significant hindcast skill of A. chilensis as an aridity proxy.  相似文献