Computational engineering and science methodologies for modeling and simulation of subsurface applications

We discuss computational engineering and science (CES) methodologies and tools applicable to a variety of subsurface models and their couplings. First we overview both basic and widely recognized multiphase and multicomponent models. In the CES methodologies area we focus on accurate and robust numerical algorithms and linear and nonlinear solvers with parallel scalability. In the CES tools area, we discuss a few representative programming tools and technologies. We present several simulation examples which reflect the experiences of the research group at the Center for Subsurface Modeling at The University of Texas at Austin.     

How multiagency partnerships can successfully address large-scale pollution problems: a Hawaii case study

Oceanic circulation patterns deposit significant amounts of marine pollution, including derelict fishing gear from North Pacific Ocean fisheries, in the Hawaiian Archipelago [Mar. Pollut. Bull. 42(12) (2001) 1301]. Management responsibility for these islands and their associated natural resources is shared by several government authorities. Non-governmental organizations (NGOs) and private industry also have interests in the archipelago. Since the marine debris problem in this region is too large for any single agency to manage, a multiagency marine debris working group (group) was established in 1998 to improve marine debris mitigation in Hawaii. To date, 16 federal, state, and local agencies, working with industry and NGOs, have removed 195 tons of derelict fishing gear from the Northwestern Hawaiian Islands. This review details the evolution of the partnership, notes its challenges and rewards, and advocates its continued use as an effective resource management tool.     

Correlated microanalysis of cometary organic grains returned by Stardust

Abstract– Carbonaceous matter in Stardust samples returned from comet 81P/Wild 2 is observed to contain a wide variety of organic functional chemistry. However, some of this chemical variety may be due to contamination or alteration during particle capture in aerogel. We investigated six carbonaceous Stardust samples that had been previously analyzed and six new samples from Stardust Track 80 using correlated transmission electron microscopy (TEM), X‐ray absorption near‐edge structure spectroscopy (XANES), and secondary ion mass spectroscopy (SIMS). TEM revealed that samples from Track 35 containing abundant aliphatic XANES signatures were predominantly composed of cometary organic matter infilling densified silica aerogel. Aliphatic organic matter from Track 16 was also observed to be soluble in the epoxy embedding medium. The nitrogen‐rich samples in this study (from Track 22 and Track 80) both contained metal oxide nanoparticles, and are likely contaminants. Only two types of cometary organic matter appear to be relatively unaltered during particle capture. These are (1) polyaromatic carbonyl‐containing organic matter, similar to that observed in insoluble organic matter (IOM) from primitive meteorites, interplanetary dust particles (IDPs), and in other carbonaceous Stardust samples, and (2) highly aromatic refractory organic matter, which primarily constitutes nanoglobule‐like features. Anomalous isotopic compositions in some of these samples also confirm their cometary heritage. There also appears to be a significant labile aliphatic component of Wild 2 organic matter, but this material could not be clearly distinguished from carbonaceous contaminants known to be present in the Stardust aerogel collector.     

SPICES: spectro-polarimetric imaging and characterization of exoplanetary systems

SPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) is a five-year M-class mission proposed to ESA Cosmic Vision. Its purpose is to image and characterize long-period extrasolar planets and circumstellar disks in the visible (450?C900 nm) at a spectral resolution of about 40 using both spectroscopy and polarimetry. By 2020/2022, present and near-term instruments will have found several tens of planets that SPICES will be able to observe and study in detail. Equipped with a 1.5 m telescope, SPICES can preferentially access exoplanets located at several AUs (0.5?C10?AU) from nearby stars (<25 pc) with masses ranging from a few Jupiter masses to Super Earths (??2 Earth radii, ??10 M_??) as well as circumstellar disks as faint as a few times the zodiacal light in the Solar System.     

High resolution investigation of the 7 μm region of the ethane spectrum

Building upon previous studies, we re-investigated the ethane spectrum between 1330 and 1610 cm^?1 by combining unapodized spectra obtained at room temperature with a Bruker Fourier transform spectrometer (FTS) in Brussels and at 131 K with a Bruker FTS in Pasadena. The maximum optical path differences (MOPD) of the two datasets were 450 and 323.7 cm, corresponding to spectral resolutions of 0.0020 and 0.0028 cm^?1, respectively. Of the 15,000 lines observed, over 4592 transitions were assigned to the ν₆ (at 1379 cm^?1), ν₈ (at 1472 cm^?1), ν₄+ν₁₂ (at 1481 cm^?1) and 2ν₄+ν₉ (at 1388 cm^?1) bands, and another 1044 transitions were located for the ν₄+ν₈?ν₄ hot band (at 1472 cm^?1). Our new analysis included an improved implementation of the Hamiltonian calculation needed to interpret the complex spectral structures caused by numerous interactions affecting these four modes of vibration. From these results, we created the first line-by-line database containing the molecular parameters for over 20,000 ¹²C₂H₆ transitions at 7 μm.     

Earth observations during space shuttle mission STS‐45 mission to planet earth March 24—April 2, 1992

Abstract

The impact of animals upon the landscape, through such actions as trampling, feeding, burrowing, mounding, and dam building, is a topic of interest in university geography classrooms. However, the relatively fine‐scale nature of most such impacts precludes its examination via remote sensing. Nevertheless, remote sensing of many types of animal impact is possible, and in this paper I illustrate several such examples, primarily drawn from free‐access sites on the World Wide Web, using a variety of remote sensing platforms. Instructors of physical geography or resource/land use management courses can thus introduce a variety of remote sensing concepts and imagery types in their classrooms while at the same time examining the role of animals on the landscape.     

Southern urbanism or a world of cities? Modes of enacting a more global urban geography in textbooks,teaching and research

Despite growing attentiveness to cities in the global south, questions remain as to how to enact a more global urban studies. We analyze five contemporary textbooks as a lens into how southern cities ought to be incorporated in teaching as well as the field of urban geography. We find both separate chapters for southern cities (southern urbanism), and southern cities integrated into existing thematic chapters (a world of cities). We further show that i) the global south is 2–33% of the content; ii) information about the south is typically more general than the north, but never as universal trends iii) representations differ not just in content but in style and iv) the south is exemplar or exception rather than as a source of theory. We suggest that geographers must continue their efforts in thinking about how southern cities should be incorporated in urban geography in and outside the classroom.     

Situating the Anthropocene: planetary urbanization and the anthropological machine

The anthropological machine is the discursive framework, the dispositif that grounds “Western man” in a sense of civility, secured through a violent division within and between the human and nonhuman: not the after-effect of the civilizing act but its very foundation. This paper explores Agamben’s machine at multiple sites: in its expression in everyday lives of urban citizens, and its legitimation of capitalist urbanization on broader spatial and temporal scales, its “worlding” through planetary urbanization and normalization of climate change. Complicit in capitalist urbanization and climate change, the anthropological machine has acted as a “switch point” since the 1600s. It now frames an emergent response: triage as the inevitable sacrifice of some peoples and parts of the planet to preserve others. If the urban is to become the site of mondialization, confronting the apparent inevitability of triage we must think beyond the either-or of a people or a planet. Thought in relation to the urban, the anthropological machine offers a meeting ground between urban political economy and assemblage urbanism. It enables us to situate the Anthropocene and differentiate the urban. But it also exposes a deep divide between scholars reframing the human beyond “Western man”: between those for whom the more-than-human expresses the dreams of a biophilic city and those for whom the less-than-human is increasingly its living nightmare.     

A Review of “Appalachian Aspirations: The Geography of Urbanization and Development in the Upper Tennessee River Valley, 1865–1900”

This article tests the explanatory power and interactions among five alternative explanations of environmental knowledge: (1) local information availability, (2) neighborhood characteristics, (3) environmental attitudes, (4) personal empowerment, and (5) information seeking. Using random forest and conditional inference trees, the article analyzes survey responses and finds that attitudes about personal empowerment and frequent information seeking are the strongest predictors of knowledge. The study offers random forest and conditional inference trees as statistical tools for complex data sets and studies that test hypotheses generated from multiple theories. We discuss the influence of knowledge differences over inclusive sustainability discussions.