Geothermal Energy for Northern Canada: Is it Economical?     

Jacek Majorowicz  Stephen E. Grasby 《Natural Resources Research》2014,23(1):159-173

We examined the potential of geothermal energy development in northern Canadian communities to support local energy demand, along with providing an initial assessment of the economic viability of geothermal energy resources for (a) low enthalpy heating systems and (b) electrical power generation from high temperature resources. We estimate yearly energy production and cost per kWh for geothermal systems using scenarios for thermal and electrical production sustained over 15 years from temperatures reached in the 2–6-km depth range. All the calculations are based on a borehole fluid productivity of 30 kg/s. We assume this to be feasible in sedimentary aquifers and through fractured granites. Under such an assumption and assumptions made on the efficiency of heat exchangers, our modeling shows that thermal energy output for 120°C from 3- to 5-km wells can be as low as 5–8 cents/kWh thermal. For a 6 km depth, the cost of thermal energy can be as low as 1–2 cents/kW thermal for thermal energy production of 100–200 MWh annually.  相似文献   

Systematic errors in weak lensing: application to SDSS galaxy–galaxy weak lensing     

Rachel Mandelbaum  Christopher M. Hirata  Uro&#; Seljak  Jacek Guzik  Nikhil Padmanabhan  Cullen Blake  Michael R. Blanton  Robert Lupton  Jonathan Brinkmann 《Monthly notices of the Royal Astronomical Society》2005,361(4):1287-1322

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Virial masses of galactic haloes from galaxy–galaxy lensing: theoretical modelling and application to Sloan Digital Sky Survey data     

Jacek Guzik  Uro&#; Seljak 《Monthly notices of the Royal Astronomical Society》2002,335(2):311-324

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Evolution of depressions on Comet 67P/Churyumov-Gerasimenko: Role of ice metamorphism     

Konrad J. Kossacki  Jacek Leliwa-Kopystyński  Slawomira Szutowicz 《Icarus》2006,184(1):221-238

This work is intended to investigate the influence of temperature-dependent metamorphism of ice on the shape of small depressions in the surface of cometary nuclei. We are mainly interested in the role of initial cohesivity of a nucleus. For this purpose we simulate sublimation of ice from the facets of initially cylindrical depressions in ice of different initial structure. The simulations account for the diurnal and orbital changes of insolation and its dependence on the current shape of the depressions. Our model includes heat transport in the cometary material and metamorphism of ice. We present the results obtained for the nucleus of the Comet 67P/Churyumov-Gerasimenko, target of the ESA cornerstone mission Rosetta.  相似文献   

Correlations between diffuse interstellar bands and atomic lines     

G. A. Galazutdinov  Giulio Manicò  Valerio Pirronello  Jacek Kre&#;owski 《Monthly notices of the Royal Astronomical Society》2004,355(1):169-177

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Impact Break-Up of Cometary Nuclei – Conclusions from Impact Experiments     

Leliwa-Kopystyński  Jacek 《Earth, Moon, and Planets》2002,90(1-4):283-291

Experiments of impact-generated break-up of icy and icy/mineral targets were performed. Formulae for the velocity of ejecta and for energy of disruption were fitted to the experimental data. An assumption that these formulae can be extrapolated for kilometer-size bodies enabled us to discuss the consequences of impacts on cometary nuclei and on planetesimals. It was found that the porosity of the targets as well as their composition (mineral to total mass ratio), are the crucial parameters.  相似文献   

Potential causes of differences between ground and surface air temperature warming across different ecozones in Alberta, Canada     

Jacek A. Majorowicz  Walter R. Skinner 《Global and Planetary Change》1997,15(3-4)

Analysis and modelling of temperature anomalies from 25 selected deep wells in Alberta show that the differences between GST (ground surface temperature) warming for the northern Boreal Forest ecozone and the combined Prairie Grassland ecozone and Aspen Parkland transition region to the south occur during the latter half of this century. This corresponds with recent changes in surface albedo resulting from permanent land development in the northern areas and also to increases in natural forest fires in the past 20 years. Differences between GST and SAT (surface air temperature) warming are much higher in the Boreal Forest ecozone than in the Prairie Grassland ecozone and Aspen Parkland transition region. Various hypotheses which could account for the existing differences between the GST and SAT warming in the different ecozones of Alberta, and western Canada in general, are tested. Analysis of existing data on soil temperature, hydrological piezometric surfaces, snowfall and moisture patterns, and land clearing and forest fires, indicate that large areas of Alberta, characterised by anomalous GST warming, have experienced widespread changes to the surface landscape in this century. It is postulated that this has resulted in a lower surface albedo with a subsequent increase in the absorption of solar energy. Heat flow modelling shows that, after climatic SAT warming, permanent clearing of the land is the most effective and likely cause of the observed changes in the GST warming. The greater GST warming in the Boreal Forest ecozone in the latter half of this century is related to landscape change due to land development and increasing forest fire activity. It appears to account for a portion of the observed SAT warming in this region through a positive feedback loop with the overlying air. The anthropogenic effect on regional climatic warming through 20th century land clearing and landscape alteration requires further study. In future, more accurate quantification of these various forcings will be necessary in order to distinguish between, and to detect, the variety of natural and anthropogenic influences and on climate.  相似文献   

On the practical stability of the triangular points in the restricted three-body problem     

Jacek Olszewski 《Celestial Mechanics and Dynamical Astronomy》1971,4(1):3-14

This paper contains a proposal of a new way of treating astrodynamical stability problems. A definition of a practical stability and a direct method of its examination are presented. The method has been applied to the triangular points problem for variety of ande values in the case of the linearized equation system as well as in the general one. The results are shown in a form which facilitates the comparison with results published by other authors.  相似文献   

WIP: A Web‐based program for indexing planar features in quartz grains and its usage          下载免费PDF全文

Anna Losiak  Izabela Golebiowska  Ludovic Ferrière  Jacek Wojciechowski  Matthew S. Huber  Christian Koeberl 《Meteoritics & planetary science》2016,51(4):647-662

Planar deformation features (PDFs) in quartz are the most important diagnostic features that allow the unambiguous identification of impact structures on Earth. In order to confirm that these features (that are characterized by planar character and form along specific crystallographic planes) are indeed PDFs, they need to be properly investigated and indexed. Following universal‐stage measurements, the process of indexing is usually performed manually, using a Wulff stereonet and following a strict procedure, which is time consuming and error prone. In this article, we present WIP, a new Web‐based program for indexing planar deformation features in quartz. The correctness of our program is shown by its application to measurements that had previously been indexed manually. The observed minor differences, especially in the absolute frequency percentage of PDFs, are negligible and not significant enough to influence the estimation of shock pressure that could be calculated from the indexed results. Usability of this program is shown using the spatial relationships between a statistically significant number of 278 quartz grains with 409 sets of PDFs analyzed within the area (~35 mm²) of a single thin section of a meta‐greywacke from the Bosumtwi impact structure. Our program is not only more accurate and faster than the manual (graphical) method but also removes the human error from the plotting process and allows control of several parameters, such as the value of estimated measurement error used in the indexing calculation or method of aggregated error handling. The program also provides information about the angles between the planes of the measured PDF sets present in a grain, which allows determination of the angles between (for example) indexed {} and {} sets.  相似文献   

Temperature and heat flux changes at the base of Laurentide ice sheet inferred from geothermal data (evidence from province of Alberta,Canada)     

Demezhko  Dmitry  Gornostaeva  Anastasia  Majorowicz  Jacek  Šafanda  Jan 《International Journal of Earth Sciences》2018,107(1):113-121

International Journal of Earth Sciences - Using a previously published temperature log of the 2363-m-deep borehole Hunt well (Alberta, Canada) and the results of its previous interpretation, the...  相似文献