The Low Inclination Dwarf Nova UY PUP     

J.J. Lockley  J.H. Wood  D.H.P. Jones  S. Mineshige 《Astrophysics and Space Science》1999,266(4):453-465

A spectroscopic study of the frequently outbursting dwarf nova UY Pup has been undertaken whilst the system was in outburst. The Hα andHβ line profiles in UY Pup are typical of low inclination dwarf novae after outburst maximum. No evidence for two components is seen in the emission lines. Using radial velocity measurements of Hα, we find the best fit orbital period for the system to be 10.22 ± 0.19 h(although we cannot with certainty rule out a period of 7.13 ± 0.14 h).We place limits on the system parameters. We also present multicolour photometry of UY Pup in quiescence. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Evaluating qualitative research: dealing with the tension between 'science' and 'creativity'   总被引：1，自引：0，他引：1  

Cathy Bailey  Catherine White  Rachel Pain 《Area》1999,31(2):169-178

Summary This paper responds to recent calls for detailed evaluative criteria for qualitative research in human geography. It argues that the dualism between 'science' and 'creativity' is unfounded, and that while systematic methods of evaluation are required, standardization is inappropriate. Furthermore, it seeks to demonstrate that grounded theory provides an alternative framework that demonstrates how these ideas might be put into practice.  相似文献   

Registration or Certification?     

Warren W. Wood 《Ground water》1999,37(1):1-1

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Oxygen-Containing Compounds Identified in Groundwater from Fuel Release Sites Using GCxGC-TOF-MS     

Kirk T. O'Reilly  Rachel E. Mohler  Dawn A. Zemo  Sungwoo Ahn  Renae I. Magaw  Catalina Espino Devine 《Ground Water Monitoring & Remediation》2019,39(4):32-40

This research continues a 7-year study of oxygen-containing organic compounds present in groundwater at gasoline and diesel fuel release sites that are quantified as diesel-range “total petroleum hydrocarbons” when measured by methods utilizing solvent extraction and gas chromatography. Two-dimensional gas chromatography with time-of-flight mass spectrometry was used to tentatively identify 1162 compounds (TICs) in 113 groundwater samples from 22 sites. Samples were collected from wells either upgradient of the release, within the source zone, or downgradient of the source but still within the plume of dissolved organics associated with release. The names and formulas of all TICs found in samples from each well type are presented and the results from upgradient and downgradient locations are compared in detail. About 60% of the most frequently detected TICs in downgradient wells were also detected in upgradient wells. A majority of these were saturated straight chain alkyl acids, commonly called fatty acids, or fatty acid esters. Of TICs frequently detected in downgradient wells but not upgradient wells, over half were branched alkyl alcohols. Hierarchical cluster analysis results suggest about 80% of the chemical composition of downgradient samples is more similar to upgradient samples than to source area samples. This similarity is due to the presence of the same types of fatty acids and esters. Principal component analysis indicates a continuum of biodegradation between the source area and downgradient samples with the latter becoming more consistent with upgradient samples. Results suggest some TICs may not be petroleum degradation intermediates but compounds synthesized by microorganisms through secondary production and carbon cycling.  相似文献   

Effects of Planting Field on Groundwater and Surface Water Pollution in China     

Yaa Opoku‐Kwanowaa  Rachel Kasoro Furaha  Li Yan  Daming Wei 《洁净——土壤、空气、水》2020,48(5-6)

Water forms an essential resource for life on earth because all living things on earth depend on water for life activities. However, with the increase in the human population, which is coupled with intense urbanization and agricultural activities, global water pollution has increased over the past decades. In China, agricultural activities that occure mainly in the planting fields have been listed as the main source of surface water and groundwater pollution. This review focuses on the major factors that influence pollution from planting fields in China mainly as a result of farming activities such as flood irrigation, excessive application of fertilizers and pesticides, and poor management practices. At present, good results are achieved by adopting soil fertilization test formula, biodegradable pesticides, proper irrigation, and agroforestry interventions. In the future, pollution from planting fields as a non‐point source of water pollution can be improved and resolved by perfect nutrient management, best management practices, organic amendments, restoring water environment, and intelligent assessment management.  相似文献   

Rock slope failure in a recently deglaciated permafrost rock wall at Piz Kesch (Eastern Swiss Alps), February 2014          下载免费PDF全文

Marcia Phillips  Andrea Wolter  Rachel Lüthi  Florian Amann  Robert Kenner  Yves Bühler 《地球表面变化过程与地形》2017,42(3):426-438

In February 2014, a rock pillar with a volume of around 150 000  m³ collapsed at Piz Kesch in the Eastern Swiss Alps. A reconstruction of the conditions prior to the event and of the event itself is presented on the basis of different sources of data. The methods applied include photogrammetry, terrestrial laser scanning, structural geological analysis, examination of meteorological data, carbon‐14 (¹⁴C) dating of organic material in permafrost ice from a tension crack and numerical modelling of likely modes of failure. Despite a complete lack of in situ measurements in the rock wall prior to the event and of direct observations during the event, the available data allow the determination of the approximate timing of the event as well as the structural predisposition, the probable mode of failure and the timescale of several millennia involved in the triggering of the failure of the rock pillar. The interdisciplinary analysis of this event contributes towards understanding the complex interaction of processes involved in large rock slope failures currently occurring in warming mountain permafrost regions. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Microplastic Contamination in Karst Groundwater Systems     

Samuel V. Panno  Walton R. Kelly  John Scott  Wei Zheng  Rachel E. McNeish  Nancy Holm  Timothy J. Hoellein  Elizabeth L. Baranski 《Ground water》2019,57(2):189-196

Groundwater in karst aquifers constitutes about 25% of drinking water sources globally. Karst aquifers are open systems, susceptible to contamination by surface-borne pollutants. In this study, springs and wells from two karst aquifers in Illinois, USA, were found to contain microplastics and other anthropogenic contaminants. All microplastics were fibers, with a maximum concentration of 15.2 particles/L. The presence of microplastic was consistent with other parameters, including phosphate, chloride and triclosan, suggesting septic effluent as a source. More studies are needed on microplastic sources, abundance, and impacts on karst ecosystems.  相似文献   

Satellite‐derived digital elevation model accuracy: hydrological modelling requirements     

T. A. Endreny  E. F. Wood  D. P. Lettenmaier 《水文研究》2000,14(2):177-194

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Perceived attributes of hurricane-related retrofits and their effect on household adoption     

Zou  Yilin  Stock  Alexia  Davidson  Rachel  Nozick  Linda  Trainor  Joseph  Kruse  Jamie 《Natural Hazards》2020,104(1):201-224

Natural Hazards - Understanding how homeowners make protective action decisions is important for designing policies and programs to encourage those actions and community resilience as a whole. This...  相似文献   

Characterization of the Rapanui mass-transport deposit and the basal shear zone: Mount Messenger Formation,Taranaki Basin,New Zealand     

Sebastian Cardona  Lesli J. Wood  Brandon Dugan  Zane Jobe  Lorna J. Strachan 《Sedimentology》2020,67(4):2111-2148

Submarine mass-transport deposits are important in many ancient and modern basins. Mass-transport deposits can play a significant role in exploration as reservoir, seal or source units. Although seismic data has advanced the knowledge about these deposits, more outcrop studies are needed to better understand gravity mass flows and predict the properties of their resultant deposits. It is proposed that sufficiently well-exposed outcrops of mass-transport deposits can be divided into three strain-dominant morphodomains: headwall, translational and toe. The outcrops of the Rapanui mass-transport deposit, part of the Lower Mount Messenger Formation in the Taranaki Basin, New Zealand, are exposed along a ca 4 km transect in coastal cliffs that enable the identification of the three morphodomains. The aim of this study is to characterize the stratigraphic and sedimentological nature of the Miocene-age Rapanui mass-transport deposit outcrops and the evolution of its basal shear zone. The basal shear zone of a mass-transport deposit is defined as the stratal zone formed in the interface between the overriding mass flow and the underlying in situ deposits or sea floor. Accordingly, the deformation structures in the Rapanui mass-transport deposit and the basal shear zone were documented in an established spatial framework. Traditional methodologies were used to characterize the sedimentology of the Rapanui mass-transport deposit. Data collected from intrafolial folds, rafted blocks and samples from the Rapanui mass-transport deposit were used to investigate strain and matrix texture evolution, estimate palaeoflow direction, and calculate yield strength and overpressure at time of deposition. Additionally, a one-dimensional numerical model was used to test sedimentation-driven overpressure as probable trigger. This work demonstrates that the basal shear zone, as well as the matrix texture of a mass-transport deposit, can vary spatially as sediments from underlying deposits are entrained during shear-derived mixing. This phenomenon can impact the seal potential of mass-transport deposits and their interaction with fluids in the subsurface.  相似文献