Mineralogische Notizen aus dem Mineralogisch-Petrographischen Institut der Universität Heidelberg     

Robert Schroeder  Werner Borchert 《Contributions to Mineralogy and Petrology》1947,1(1):110-111

Ohne Zusammenfassung  相似文献   

Comparison of the microbial community composition of pristine rock cores and technical influenced well fluids from the Ketzin pilot site for CO<Subscript>2</Subscript> storage     

Linda Pellizzari  Daria Morozova  Dominik Neumann  Monika Kasina  Stefan Klapperer  Michael Zettlitzer  Hilke Würdemann 《Environmental Earth Sciences》2016,75(19):1323

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Drivers of social media use among African Americans in the event of a crisis   总被引：1，自引：1，他引：0  

Lori Pennington-Gray  Kiki Kaplanidou  Ashley Schroeder 《Natural Hazards》2013,66(1):77-95

Research has examined the role of social media during the time of a crisis in various fields; however, there is a paucity of research in this area as it relates to tourism. Moreover, few studies have examined at-risk populations, such as tourists, in times of crisis. To assess the drivers of turning to social media during a crisis, a national survey of 1,018 African American travelers was conducted. Respondents were asked to indicate on a 5-point scale the likelihood of turning to social media for information “if they were currently in the middle of their trip and heard that a crisis has just occurred within the immediate vicinity of their current location.” Hierarchical regression analysis was conducted to determine drivers on African American travelers’ decisions to use social media during a crisis. These drivers were age, perceptions of risk during their trip, and frequency and type of social media use engaged in on a regular basis. Overall, findings suggested that when controlling for age only, crime, financial, and physical perceptions of risk drove social media use during a crisis, while controlling for age and perception of risk, use of social media in one's daily life showed no influence.  相似文献   

Designing policy for deployment of CCS in industry     

Tom Mikunda  Heleen de Coninck  Morgan Bazilian  Hilke Rösler  Bob van der Zwaan 《Climate Policy》2013,13(5):665-676

Attaining deep greenhouse gas (GHG) emission reductions in industry in order to support a stringent climate change control target will be difficult without recourse to CO₂ capture and storage (CCS). Using the insights from a long-term bottom-up energy systems model, and undertaking a sectoral assessment, we investigated the importance of CCS in the industrial sector. Under climate policy aimed at limiting atmospheric concentration of GHGs to 650 ppm CO₂e, costs could increase fivefold when CCS is excluded from the portfolio of mitigation option measures in the industry sector as compared to when CCS is excluded in the power sector. This effect is driven largely by the lack of alternatives for deep emission reductions in industry. Our main policy conclusion is that a broader recognition of CCS in industrial applications in both current policy discussions and research, development, and demonstration funding programmes is justified. In recognition of the heterogeneity of the many types of industrial production processes, the size and location of industrial CO₂ sources, the specific need for CCS-retrofitting, and the exposure of most industrial sectors to international trade, policies aimed at supporting CCS must distinguish between the different challenges faced by the power and industrial sectors.  相似文献   

Mechanical behaviour of Lixhe chalk partly saturated by oil and water: experiment and modelling     

F. Collin  Y. J. Cui  C. Schroeder  R. Charlier 《国际地质力学数值与分析法杂志》2002,26(9):897-924

Two or more different fluids generally saturate chalk in oil reservoir, and therefore its behaviour can be very complicated. In this paper, a constitutive law is proposed for modelling the mechanical behaviour of a chalk saturated by two non‐miscible fluids, water and oil. The effects of the capillary pressure or suction are taken into account. They are considered as an independent variable, as in the Barcelona's basic model developed for unsaturated soils. On the other hand, internal friction and pore collapse are modelled as independent mechanisms. The determination of the parameters is based on triaxial and oedometer tests. Finally, in order to validate the model, predictions are compared with experimental results of water‐flooding test. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

The circulation of the western Mediterranean Sea in spring 2005 as inferred from observations and from model outputs     

K. Schroeder  V. Taillandier  A. Vetrano  G.P. Gasparini 《Deep Sea Research Part I: Oceanographic Research Papers》2008,55(8):947-965

In situ observations and numerical model simulations have been used to study the circulation of the western Mediterranean Sea during April–May 2005. A hydrological survey and direct current measurements carried out in the western Mediterranean Sea are analyzed with an inverse box model. The model result is a mean circulation of the region during spring 2005 along with simultaneous evaluation of water fluxes through eight transects and associated uncertainties. In order to evaluate the consistency of the results and the weight of currents at shorter temporal and spatial scales, an inter-comparison of differently achieved results is performed. The inverse solution is evaluated against both instantaneous current measurements and simulated velocity fields from a General Circulation Model. The results obtained and the general agreement between the three approaches are encouraging and confirms that the inverse box model is a powerful instrument to investigate flow fields in wide areas of the sea. The picture coming out confirms the previous qualitative knowledge on the mean circulation at all levels, providing, in addition, robust quantitative estimations of the water masses fluxes throughout the western Mediterranean basin.  相似文献   

Small Solar Wind Transients and Their Connection to the Large-Scale Coronal Structure     

E. K. J. Kilpua  J. G. Luhmann  J. Gosling  Y. Li  H. Elliott  C. T. Russell  L. Jian  A. B. Galvin  D. Larson  P. Schroeder  K. Simunac  G. Petrie 《Solar physics》2009,256(1-2):327-344

It has been realized for some time that the slow solar wind with its embedded heliospheric current sheet often exhibits complex features suggesting at least partially transient origin. In this paper we investigate the structure of the slow solar wind using the observations by the Wind and STEREO spacecraft during two Carrington rotations (2054 and 2055). These occur at the time of minimum solar activity when the interplanetary medium is dominated by recurrent high-speed streams and large-scale interplanetary coronal mass ejections (ICMEs) are rare. However, the signatures of transients with small scale-sizes and/or low magnetic field strength (comparable with the typical solar wind value, ～?5 nT) are frequently found in the slow solar wind at these times. These events do not exhibit significant speed gradients across the structure, but instead appear to move with the surrounding flow. Source mapping using models based on GONG magnetograms suggests that these transients come from the vicinity of coronal source surface sector boundaries. In situ they are correspondingly observed in the vicinity of high density structures where the dominant electron heat flux reverses its flow polarity. These weak transients might be indications of dynamical changes at the coronal hole boundaries or at the edges of the helmet streamer belt previously reported in coronagraph observations. Our analysis supports the idea that even at solar minimum, a considerable fraction of the slow solar wind is transient in nature.  相似文献   

Effects of thermal energy storage on shallow aerobic aquifer systems: temporary increase in abundance and activity of sulfate-reducing and sulfur-oxidizing bacteria     

Tobias Lienen  Klas Lüders  Hannah Halm  Anke Westphal  Ralf Köber  Hilke Würdemann 《Environmental Earth Sciences》2017,76(6):261

Aquifer thermal energy storage may result in increases in the groundwater temperature up to 70 °C and more. This may lead to geochemical and microbiological alterations in the aquifer. To study the temperature effects on the indigenous microbial community composition, sediment column experiments at four different temperatures were carried out and the effluents were characterized geochemically and microbiologically. After an equilibrium phase at groundwater temperature of 10 °C for 136 days, one column was kept at 10 °C as a reference and the others were heated to 25, 40 and 70 °C. Genetic fingerprinting and quantitative PCR revealed a change in the bacterial community composition and abundance due to the temperature increase. While at 25 °C only slight changes in geochemical composition and gene copy numbers for bacteria were observed, increasing concentrations of total organic carbon in the 40 °C column were followed by a strong increase in bacterial abundance. Thermophilic bacteria became dominant at 70 °C. Temporary sulfate reduction took place at 40 and 70 °C and this correlated with an increased abundance of sulfate-reducing bacteria (SRB). Furthermore, a coexistence of SRB and sulfur-oxidizing bacteria (SOB) at all temperatures indicated an interaction of these physiological groups in the sediments. The results show that increased temperatures led to significant shifts in the microbial community composition due to the altered availability of electron donors and acceptors. The interplay of SRB and SOB in sedimentary biofilms facilitated closed sulfur cycling and diminished harmful sulfur species.  相似文献   

Tanzanite as conflict gem: Certifying a secure commodity chain in Tanzania     

Richard A. Schroeder 《Geoforum》2010,41(1):56-65

Shortly after the September 11, 2001 attacks in the United States, the Wall Street Journal published an article claiming that al Qaeda sympathizers were using an obscure gemstone commodity known as tanzanite to raise funds for terrorist activities. Despite subsequent disclaimers by the US State Department, this allegation effectively marked tanzanite as a “conflict gem,” and set in motion a complex set of political maneuvers designed to rehabilitate the tanzanite industry’s reputation. This paper analyzes the immediate fallout from the Wall Street Journal article and the subsequent effects of anti-terrorist rhetoric on the tanzanite industry. I explore the origins of the “conflict gem” discourse and the political movement that has taken shape over the past decade to reform gemstone mining. Drawing on theories developed by critics of the fair trade movement, I examine a series of steps taken by the main corporate miner active in the tanzanite industry to re-brand and certify tanzanite as “conflict-free.” I underscore the degree to which these efforts have been inflected by new security provisions embodied in the USA Patriot Act.  相似文献   

ENSO and seasonal sea-level variability – A diagnostic discussion for the U.S.-Affiliated Pacific Islands     

Md. R. Chowdhury  P.-S. Chu  T. Schroeder 《Theoretical and Applied Climatology》2007,88(3-4):213-224

Summary The El Ni?o-Southern Oscillation (ENSO) climate cycle is the basis for this paper, aimed at providing a diagnostic outlook on seasonal sea-level variability (i.e. anomalies with respect to the Climatology) for the U.S.-Affiliated Pacific Islands (USAPI). Results revealed that the sea-level variations in the northwestern tropical Pacific islands (e.g. Guam and Marshall Islands) have been found to be sensitive to ENSO-cycle, with low sea-level during El Ni?o and high sea-level during La Ni?a events. The annual cycle (first harmonic) of sea-level variability in these north Pacific islands has also been found to be very strong. The composites of SST and circulation diagnostic show that strong El Ni?o years feature stronger surface westerly winds in the equatorial western/central Pacific, which causes north Pacific islands to experience lower sea-level from July to December, while the sea-level in south Pacific islands (e.g. American Samoa) remains unchanged. As the season advances, the band of westerly winds propagates towards the south central tropical Pacific and moves eastward, which causes American Samoa to experience a lower sea-level from January to June, but with six months time lag as compared to Guam and the Marshalls. U.S.-Affiliated Pacific Islands are among the most vulnerable communities to climate variability and change. This study has identified the year-to-year ENSO climate cycle to have significant impact on the sea-level variability of these islands. Therefore, regular monitoring of the ENSO climate cycle features that affect seasonal sea-level variability would provide substantial opportunities to develop advance planning and decision options regarding hazard management in these islands.  相似文献