نتایج جستجو برای: geochemical indicator

تعداد نتایج: 87188  

1992
FORREST M. HOFFMAN VIJAY S. TRIPATHI

-This paper presents the design and development of a Geochemical Expert System prototype (GES) for analyzing solution-mineral interactions in nature. The emphasis is placed on expert system design and knowledge representation. One of the most challenging and research-intensive steps was the identification of the key geochemical characteristics that would enable the expert system to identify sal...

2016
B. Fiałkiewicz-Kozieł B. Smieja-Król M. Frontasyeva M. Słowiński K. Marcisz E. Lapshina D. Gilbert A. Buttler V. E. J. Jassey K. Kaliszan F. Laggoun-Défarge P. Kołaczek M. Lamentowicz

As human impact have been increasing strongly over the last decades, it is crucial to distinguish human-induced dust sources from natural ones in order to define the boundary of a newly proposed epoch - the Anthropocene. Here, we track anthropogenic signatures and natural geochemical anomalies in the Mukhrino peatland, Western Siberia. Human activity was recorded there from cal AD 1958 (±6). An...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2015
Marc P Verhougstraete Sherry L Martin Anthony D Kendall David W Hyndman Joan B Rose

Linking fecal indicator bacteria concentrations in large mixed-use watersheds back to diffuse human sources, such as septic systems, has met limited success. In this study, 64 rivers that drain 84% of Michigan's Lower Peninsula were sampled under baseflow conditions for Escherichia coli, Bacteroides thetaiotaomicron (a human source-tracking marker), landscape characteristics, and geochemical an...

Journal: :Computers & Geosciences 2008
Yan Wang Wei Shen Pengda Zhao

Measurements that describe and summarize quantitative predictions relating to the classification of geological variables and samples derived from geochemical and geophysical data sets are important because of the large amount of information contained in such data. Methods considered in mineral resource quantitative prediction include quantification theory, which is able to deal with data includ...

2014
Jianjun Wang Liqi Chen Li Li Jianhua He Jian Chen Chuanjie Jiang Weiguo Wang Sabrina Li Yiliang Li Rui Zhang

A major challenge in palaeohydrology is the extraction of continuous palaeoflood information from geophysical records. A high-resolution sediment core off the Minjiang estuary area in the Taiwan Strait, SE China, records the sedimentation history from approximately 1660 to the present. The alkane ratio C31/C17, a classic organic geochemical indicator of terrestrial/aquatic matter, peaks in the ...

Journal: :Anais da Academia Brasileira de Ciencias 2006
Eugénio A Correia Fernando A T P Laiginhas

This work presents a geochemical study of a set of garnets, selected by their colors, from the Camafuca-Camazambo kimberlite, located on northeast Angola. Mantle-derived garnets were classified according to the scheme proposed by Grütter et al. (2004) and belong to the G1, G4, G9 and G10 groups. Both sub-calcic (G10) and Ca-saturated (G9) garnets, typical, respectively, of harzburgites and lher...

2006
PHILIP J. BINNING MICHAEL A. CELIA LI LI

Multicomponent contaminant transport models in groundwater are typically based on assumptions of local geochemical equilibrium on the grid scale. In heterogenous systems there may be significant coupling between transport processes and geochemical equilibrium at smaller than grid block scale. When these processes are upscaled to grid scale, geochemical evolution may take on a kinetic character....

2008
Jeffrey M Dick

Background: Proteins of various compositions are required by organisms inhabiting different environments. The energetic demands for protein formation are a function of the compositions of proteins as well as geochemical variables including temperature, pressure, oxygen fugacity and pH. The purpose of this study was to explore the dependence of metastable equilibrium states of protein systems on...

2010
Pranab Das Sridhar D Iyer

The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB) under one class i.e., as mid-oceanic ridge basalts (MORB). Hence, a method is specifically needed to identify the OFB as normal (N-MORB), enriched (E-MORB) and ocean island basalts (OIB). We have applied Artificial Neur...

2016
Jaana Jarva Timo Tarvainen Reijo Salminen

This study provides an overview on the development of the guidelines and legislation related to soil contamination in Finland, with the main focus on geochemical baselines. The use of geochemical baseline surveys in the assessment soil contamination in Finland and in some other countries is briefly discussed and the current practices in Finland are presented. Finally, the geochemical baselines ...

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