Foreword: lessons learned about contaminant hydrogeology from legacy research sites     

Anderson MP  McCray J 《Ground water》2011,49(5):617-619

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Market intermediaries and rural people in Bolivia's forest products sector: Are trusting partnerships possible?     

James T. Murphy  Mary Lawhon 《Singapore journal of tropical geography》2011,32(2):203-219

Decentralization in access to and control of Bolivia's forest resources, coupled with a rising global demand for tropical hardwoods, raises important questions about whether increased trade and community forest management (CFM) initiatives can enable forms of market integration that have more favourable outcomes for rural communities. This paper assesses the prospects for such a transition through an examination of the relationships linking wood product market intermediaries (brokers and buyers) to rural suppliers and forest communities in Bolivia. The analysis centres on whether trust – conceptualized as a power‐laden sociospatial process driven by multiscalar factors – can evolve between buyers and suppliers such that more progressive (sustainable and mutually beneficial) partnerships devolop. Focusing on three types of buyer–supplier relationships in Bolivia – direct ties between wood brokers/buyers and suppliers, nongovernmental organization (NGO) mediated exchange relationships and Forest Stewardship Council (FSC) certification of suppliers – our findings show how trust building initiatives that focus on one scale may fail if factors at other scales create obstacles to collaboration, Given these relational constraints, CFM strategies in Bolivia currently face limitation on their viability as economic development strategies.  相似文献   

FT-IR measurements of cold C₃H₈ cross sections at 7–15 μm for Titan atmosphere     

Keeyoon Sung  Geoffrey C. Toon  Arlan W. Mantz  Mary Ann H. Smith 《Icarus》2013

We present absorption cross sections of propane (C₃H₈) at temperatures from 145 K to 297 K in the 690–1550 cm⁻¹ region. Pure and N₂-broadened spectra were measured at pressures from 3 Torr to 742 Torr using a Bruker IFS125 FT-IR spectrometer at JPL. The gas absorption cell, developed at Connecticut College, was cooled by a closed-cycle helium refrigerator. The cross sections were measured and compiled for individual spectra recorded at various experimental conditions covering the planetary atmosphere and Titan. In addition to the cross sections, a propane pseudoline list with a frequency grid of 0.005 cm⁻¹, was fitted to the 34 laboratory spectra. Line intensities and lower state energies were retrieved for each line, assuming a constant width. Validation tests showed that the pseudoline list reproduces discrete absorption features and continuum, the latter contributed by numerous weak and hot band features, in most of the observed spectra within 3%. Based on the pseudoline list, the total intensity in the 690–1550 cm⁻¹ region was determined to be 52.93 (±3%) × 10⁻¹⁹ cm⁻¹/(molecule cm⁻²) at 296 K; this value is within 3% of the average from four earlier studies. Finally, the merit of the pseudoline approach is addressed for heavy polyatomic molecules in support of spectroscopic observation of atmospheres of Titan and other planets. The cold cross sections will be submitted to the HITRAN database (hitran.harvard.edu), and the list of C₃H₈ pseudolines will be available from a MK-IV website of JPL (http://mark4sun.jpl.nasa.gov/data/spec/Pseudo).  相似文献   

Bastnaesite from Kanigiri granite, Prakasam district, Andhra Pradesh     

G. Nagendra Babu  M. Sai Baba  Mary K. Kumar  Yamuna Singh  P. V. Ramesh Babu  P. S. Parihar 《Journal of the Geological Society of India》2013,81(4):447-450

For the first time we report bastnaesite and hydroxyl bastnaesite (lanthanum cerium fluoro-carbonate) from the Kanigiri granite. The host granitoids are of A-type and vary in composition from quartz syenites to peralkaline granites. Rare metal and rare earth-bearing minerals identified by X-ray diffraction (XRD) studies in Kanigiri granite are bastnaesite and hydroxyl bastnaesite, besides columbite-tantalite, monazite, fergusonite, thorite and euxenite. Petromineralogical studies have also revealed the presence of bastnaesite. The presence of bastnaesite in Kanigiri granite suggests that the host felsic rocks may also form a potential source for light rare earth mineral, bastnaesite, apart from the already known rare-metal minerals.  相似文献   

A discontinuous Galerkin method for two-phase flow in a porous medium enforcing H(div) velocityand continuous capillary pressure     

Todd Arbogast  Mika Juntunen  Jamie Pool  Mary F. Wheeler 《Computational Geosciences》2013,17(6):1055-1078

We consider the slightly compressible two-phase flow problem in a porous medium with capillary pressure. The problem is solved using the implicit pressure, explicit saturation (IMPES) method, and the convergence is accelerated with iterative coupling of the equations. We use discontinuous Galerkin to discretize both the pressure and saturation equations. We apply two improvements, which are projecting the flux to the mass conservative H(div)-space and penalizing the jump in capillary pressure in the saturation equation. We also discuss the need and use of slope limiters and the choice of primary variables in discretization. The methods are verified with two- and three-dimensional numerical examples. The results show that the modifications stabilize the method and improve the solution.  相似文献   

Buruanga peninsula and Antique Range: Two contrasting terranes in Northwest Panay,Philippines featuring an arc–continent collision zone     

Lawrence R. Zamoras  Mary Grace A. Montes  Karlo L. Queaño  Edanjarlo J. Marquez  Carla B. Dimalanta  Jillian Aira S. Gabo  Graciano P. Yumul Jr. 《Island Arc》2008,17(4):443-457

Alternating chert–clastic sequences juxtaposed with limestone blocks, which are units typical of accretionary complexes, constitute the Buruanga peninsula. New lithostratigraphic units are proposed in this study: the Unidos Formation (Jurassic chert sequence), the Saboncogon Formation (Jurassic siliceous mudstone–terrigenous mudstone and quartz‐rich sandstone), the Gibon Formation (Jurassic(?) bedded pelagic limestone), the Libertad Metamorphics (Jurassic–Cretaceous slate, phyllite, and schist) and the Buruanga Formation (Pliocene–Pleistocene reefal limestone). The first three sedimentary sequences in the Buruanga peninsula show close affinity with the ocean plate stratigraphy of the North Palawan terrane in Busuanga Island: Lower–Middle Jurassic chert sequences overlain by Middle–Upper Jurassic clastics, juxtaposed with pelagic limestone. Moreover, the JR5–JR6 (Callovian to Oxfordian) siliceous mudstone of the Saboncogon Formation in the Buruanga peninsula correlates with the JR5–JR6 siliceous mudstone of the Guinlo Formation in the Middle Busuanga Belt. These findings suggest that the Buruanga peninsula may be part of the North Palawan terrane. The rocks of the Buruanga peninsula completely differ from the Middle Miocene basaltic to andesitic pyroclastic and lava flow deposits with reefal limestone and arkosic sandstone of the Antique Range. Thus, the previously suggested boundary between the Palawan microcontinental block and the Philippine Mobile Belt in the central Philippines, which is the suture zone between the Buruanga peninsula and the Antique Range, is confirmed. This boundary is similarly considered as the collision zone between them.  相似文献   

Vulnerability and adaptation to climate-related fire impacts in rural and urban interior Alaska     

Sarah F. Trainor  Monika Calef  David Natcher  F. Stuart Chapin III  A. David McGuire  Orville Huntington  Paul Duffy  T. Scott Rupp  La'Ona DeWilde  Mary Kwart  Nancy Fresco  & Amy Lauren Lovecraft 《Polar research》2009,28(1):100-118

This paper explores whether fundamental differences exist between urban and rural vulnerability to climate-induced changes in the fire regime of interior Alaska. We further examine how communities and fire managers have responded to these changes and what additional adaptations could be put in place. We engage a variety of social science methods, including demographic analysis, semi-structured interviews, surveys, workshops and observations of public meetings. This work is part of an interdisciplinary study of feedback and interactions between climate, vegetation, fire and human components of the Boreal forest social–ecological system of interior Alaska. We have learned that although urban and rural communities in interior Alaska face similar increased exposure to wildfire as a result of climate change, important differences exist in their sensitivity to these biophysical, climate-induced changes. In particular, reliance on wild foods, delayed suppression response, financial resources and institutional connections vary between urban and rural communities. These differences depend largely on social, economic and institutional factors, and are not necessarily related to biophysical climate impacts per se. Fire management and suppression action motivated by political, economic or other pressures can serve as unintentional or indirect adaptation to climate change. However, this indirect response alone may not sufficiently reduce vulnerability to a changing fire regime. More deliberate and strategic responses may be required, given the magnitude of the expected climate change and the likelihood of an intensification of the fire regime in interior Alaska.  相似文献   

Part II. Discontinuous Galerkin method applied to a single phase flow in porous media     

Béatrice Riviè;re  Mary F. Wheeler  Krzysztof Banaś 《Computational Geosciences》2000,4(4):337-349

Discontinuous Galerkin numerical simulations of single phase flow problem are described in this paper. The simulations show the advantages of using discontinuous approximation spaces. hp convergence results are obtained for smooth solutions. Unstructured meshes and unsmooth solutions are also considered.  相似文献   

The Stratigraphy,Sedimentology, and Fossils of the Haughton Formation: A Post-Impact Crater-Fill,Devon Island,N.W.T., Canada     

Leo J. Hickey  Kirk R. Johnson  Mary R. Dawson 《Meteoritics & planetary science》1988,23(3):221-231

Abstract— After the impact that formed Haughton crater, 22.4 ± 1.4 Ma ago (early Miocene), the cavity filled with water and began to accumulate lacustrine sediments. These preserve detailed evidence of pre-impact stratigraphy and post-impact morphology and development of the crater, as well as of the climatic and biotic regime in which it lay. In this report we formally designate these sediments as the Haughton Formation, of which only a 48 m thick remnant covering approximately 7 km² still exists. Dolomite-rich, poorly-sorted silt, fine sand, and mud are the principal lithologies. The formation unconformably overlies a blanket of allochthonous impact breccia forming the floor of the original crater. Presence of a debris-flow deposit in the base of the sequence indicates that lacustine deposition began very shortly after crater formation. The Haughton Formation contains a moderately diverse and highly endemic vertebrate fauna as well as palynomorphs and plant macrofossils that indicate a cool-temperate climatic regime. A small percentage of reworked Late Cretaceous and early Tertiary palynomorphs point to the former existence of the Eureka Sound Formation in the drainage area of the crater. In addition, the distribution of the lake beds indicates the absence of an inner ring on the west side of the crater, and the 3° to 3.5° inward dip of Haughton strata implies that the central mass has subsided approximately 300 to 350 m since deposition began.  相似文献   

Photographic monitoring of soiling and decay of roadside walls in central Oxford, England     

Mary J. Thornbush  Heather A. Viles 《Environmental Geology》2008,56(3-4):777-787

As part of the Environmental Monitoring of Integrated Transport Strategies (EMITS) project, which examined the impact of the Oxford Transport Strategy (OTS) on the soiling and decay of buildings and structures in central Oxford, England, a simple photographic survey of a sample of roadside walls was carried out in 1997, with re-surveys in 1999 and 2003. Thirty photographs were taken each time, covering an area of stonework approximately 30 × 30 cm in dimensions at 1–1.3 m above pavement level. The resulting images have been used to investigate, both qualitatively as well as quantitatively, the progression of soiling and decay. Comparison of images by eye reveals a number of minor changes in soiling and decay patterns, but generally indicates stability except at one site where dramatic, superficial damage occurred over 2 years. Quantitative analysis of decay features (concavities resulting from surface blistering, flaking, and scaling), using simple techniques in Adobe Photoshop, shows variable pixel-based size proportions of concavities across 6 years of survey. Colour images (in Lab Color) generally have a reduced proportion of pixels, representing decay features in comparison to black and white (Grayscale) images. The study conveys that colour images provide more information both for general observations of soiling and decay patterns and for segmentation of decay-produced concavities. The study indicates that simple repeat photography can reveal useful information about changing patterns of both soiling and decay, although unavoidable variation in external lighting conditions between re-surveys is a factor limiting the accuracy of change detection.  相似文献