Search results: Found 13

Listing 1 - 10 of 13 << page
of 2
>>
Sort by
Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889450817 Year: Pages: 242 DOI: 10.3389/978-2-88945-081-7 Language: English
Publisher: Frontiers Media SA
Subject: Chemistry (General) --- Geography --- Oceanography --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
License:

Loading...
Export citation

Choose an application

Abstract

A substantial increase in the number of studies using the optical properties (absorbance and fluorescence) of dissolved organic matter (DOM) as a proxy for its chemical properties in estuaries and the coastal and open ocean has occurred during the last decade. We are making progress on finding the actual chemical compounds or phenomena responsible for DOM’s optical properties. Ultrahigh resolution mass spectrometry, in particular, has made important progress in making the key connections between optics and chemistry. But serious questions remain and the last major special issue on DOM optics and chemistry occurred nearly 10 years ago. Controversies remain from the non-specific optical properties of DOM that are not linked to discrete sources, and sometimes provide conflicting information. The use of optics, which is relatively easier to employ in synoptic and high resolution sampling to determine chemistry, is a critical connection to make and can lead to major advances in our understanding of organic matter cycling in all aquatic ecosystems. The contentions and controversies raised by our poor understanding of the linkages between optics and chemistry of DOM are bottlenecks that need to be addressed and overcome.

Selenium Isotope Studies in Plants - Development and Validation of a Novel Geochemical Tool and its Application to Organic Samples

Author:
Book Series: Karlsruher mineralogische und geochemische Hefte : Schriftenreihe des Instituts für Angewandte Geowissenschaften ISSN: 16182677 ISBN: 9783731505945 Year: Volume: 42 Pages: XXV, 223 p. DOI: 10.5445/KSP/1000060292 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Ethnology
Added to DOAB on : 2019-07-30 20:02:00
License:

Loading...
Export citation

Choose an application

Abstract

Selenium (Se), being an essential nutrient and a toxin, enters the food chain mainly via plants. Selenium isotope signatures were proved to be an excellent redox tracer, making it a promising tool for the exploration of the Se cycle in plants. The analytical method is sensitive on organic samples and requires particular preparation methods, which were developed and validated in this study. Plant cultivation setups revealed the applicability of these methods to trace plant internal processes.

Polymetallic Metallogenic System

Author:
ISBN: 9783039212934 9783039212941 Year: Pages: 538 DOI: 10.3390/books978-3-03921-294-1 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General)
Added to DOAB on : 2019-12-09 16:10:12
License:

Loading...
Export citation

Choose an application

Abstract

Within the last decade, the high and continuing demand for precious and base metals, as well as critical elements, has prompted a global rush on a scale never before seen. This eventually resulted in the demand for considerable innovation and improvement in mineral deposit genetic modelling and ore formation regimes for the many different types of gold deposits, now recognized, and paralleled by the wide employment of exploration techniques and a rapid expansion of geological databases. This Special Issue will show case studies of porphyry polymetal systems, orogenic gold formations, water–rock reaction, ore-forming structure evolution, mineralogy and petrology of ore deposit, ore formation regime, geochronology and geochemistry of ore deposit, ore-forming evolution, mineral exploration and cutting-edge technology in ore deposit study.

Keywords

W–Sn skarn --- whole-rock geochemistry --- Huangshaping --- Shizhuyuan --- Xianghualing --- Rare-Earth Elements --- C–O isotopes --- hydrothermal calcite --- ore-forming processes --- Phapon gold deposit --- oxidation state --- hydrous melts --- constraints on mineralization --- Beiya Au deposit --- SW China --- zircon geochronology --- magmatic oxygen fugacity --- petrogenesis --- Zaozigou deposit --- West Qinling --- archean basement --- quartz vein --- hydrothermal alteration halo --- Pinglidian gold deposit --- Jiaodong --- geochemistry --- U–Pb zircon age --- Sr–Nd isotopes --- Haoyaoerhudong gabbro --- Inner Mongolia --- geochronology --- Hf isotopes --- petrogenesis --- paleo-Tethyan ocean closure --- Zaorendao gold deposit --- West Qinling --- syenite --- post-collisional --- niobium mineralization --- Saima deposit --- Liaoning Province --- invisible gold --- visible gold --- LA-ICP-MS --- Yangshan gold belt --- West Qinling --- zircon U-Pb dating --- molybdenite Re-Os dating --- zircon Hf isotopes --- Weilasituo Sn-polymetallic deposit --- Inner Mongolia --- orogenic-gold deposit --- mineral geo-thermometry --- physicochemical condition of mineralization --- Zhengchong gold deposit --- Jiangnan orogenic belt --- lithospheric architecture --- metallogenesis --- Hf-Nd isotopic mapping --- Liaodong Peninsula --- North China Craton --- zircon U–Pb geochronology --- Sr–Nd–Pb–Hf isotopes --- low Sr and high Yb A2-type granite --- Xianghualing --- South China --- fluid inclusion --- stable isotopes --- gold deposition --- Sanshandao gold deposit --- Jiaodong --- fluid inclusions --- H–O isotope --- immiscibility --- water–rock interaction --- Sizhuang gold deposit --- Jiaodong Peninsula --- China --- Pulang porphyry Cu (–Mo–Au) deposit --- LA-ICP-MS zircon U–Pb dating --- molybdenite Re–Os dating --- high-silica adakitic rocks (HSA) --- Northwestern Yunnan Province --- C–H–O isotopes --- fluid inclusion --- Koka deposit --- orogenic gold deposit --- ore shoots --- structural control --- geostatistics --- Sizhuang gold deposit --- Jiaodong Peninsula --- skarn mineralogy --- high fugacity --- garnet Sm–Nd dating --- Late Cretaceous --- Hongshan skarn deposit --- mantle branch --- metallogenesis --- ore-controlling structures --- metallogenic rule --- ore prospecting target --- Jiaodong area --- zircon U–Pb dating --- Re–Os dating --- middle–late Jurassic --- Mo-polymetallic deposit --- Great Xing’an Range --- Dongbulage --- A-type granite --- tin mineralization --- Tiantangshan tin polymetallic deposit --- SE China --- Chishan alkaline complex --- rock geochemistry --- zircon U–Pb dating --- Lu–Hf isotopes --- Hegenshan-Heihe suture zone --- Cu-Au hydrothermal mineralization --- Hongyan deposit --- Permian A-type granite --- granite petrogenesis --- magmatic oxygen fugacity --- post-collisional slab break-off --- quartz --- trace element --- precipitation mechanism --- in situ study --- sericite --- acidity --- formation temperature --- n/a

Mineralogy and Geochemistry of Gems

Authors: --- --- ---
ISBN: 9783039280766 9783039280773 Year: Pages: 528 DOI: 10.3390/books978-3-03928-077-3 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Geology --- Earth Sciences
Added to DOAB on : 2020-04-07 23:07:09
License:

Loading...
Export citation

Choose an application

Abstract

Gems have been used in the manufacture of jewellery and as ornaments since antiquity. Considering gems, recent statistics have shown that about 15 billion Euros are annually at stake. Nowadays, gemmology, i.e., the study of gem materials, is one of the most expanding fields in the earth sciences, positioned between academia and industry. As an applied science, in gemmology, the instruments used should be non- or microdestructive, and their cost should be reasonable both in terms of equipment and time consumption. Gemmology can also be used contribute to the development of pure science and in some cases, destructive techniques may have to be used. Taking into account the fact that gems are albeit rarely available for scientific research, this compilation of 20 articles by around 100 researchers from over 30 different institutions situated in 20 countries from around the globe, presented in the Special Issue entitled “Mineralogy and Geochemistry of Gems”, offers very good examples on the application of various methods for their study which will hopefully contribute to our better understanding of gem formation in general and will enhance scientific debates attracting more scientists from various disciplines to get involved in this field.

Keywords

danburite --- trace elements --- REE --- femtosecond LA-ICP-MS --- CHNS elemental analyzer --- pegmatites --- skarn --- gemstones --- placer --- heavy and light minerals --- landforms --- climate --- geodynamic setting --- green quartz --- prase --- amethyst --- color --- amphibole --- actinolite --- skarn --- Serifos --- Greece --- zircon --- xenocryst --- alkali basalt --- Ratanakiri Volcanic Province --- trace elements --- O-isotopes and Hf-isotopes --- U-Pb --- (U-Th)/He --- granitic pegmatite --- gem-quality tourmaline --- Adamello Massif --- Central Alps --- Italy --- ruby --- Mogok --- Mong Hsu --- New South Wales --- trace elements --- LA-ICP-MS analysis --- inclusions --- U–Pb age-dating --- genetic diversity --- geographic typing --- corundum --- blue sapphire --- meta-ultramafic rocks --- LA-ICP-MS --- Rb-Sr and Sm-Nd isotopy --- Ilmenogorsky complex --- Ural Mountains --- metasomatism --- corundum megacrysts --- ruby --- sapphire --- plumasite --- metamorphic-metasomatic origin --- Greece --- zircon megacrysts --- placer deposits --- rare earth elements (REE) --- carbonatite-dominant melts --- Central Highlands --- Vietnam --- hyperspectral photoluminescence imaging --- LA-ICP-MS --- rubies --- corundum --- in-situ oxygen isotopes --- Paranesti Greece --- Nestos Shear Zone --- Secondary ion mass spectrometry (SIMS) --- emerald deposits --- classification --- typology --- metamorphism --- magmatism --- sedimentary --- alkaline metasomatism --- fluids --- stable and radiogenic isotopes --- genetic models --- exploration --- andradite --- demantoid --- gemstone --- Raman spectroscopy --- UV-Vis-NIR spectroscopy --- X-ray fluorescence spectroscopy --- gem-quality --- garnet --- gem-bearing pegmatite --- fluid inclusions --- P-T-X equilibria --- spodumene --- Ar/Ar dating --- blue sapphire --- anorthosites --- kyshtymites --- sapphire geochemistry --- Ilmenogorsky-Vishnevogorsky complex --- in situ LA-ICP-MS U-Pb zircon dating --- kyanite --- Mn-rich silicates --- Rhodope --- Thassos --- amphibolite facies --- metasomatism --- opal --- hyalite --- silica --- X-ray diffraction --- Raman --- Infrared --- 29Si nuclear magnetic resonance --- SEM --- provenance --- pearls --- freshwater --- saltwater --- LA-ICP-MS --- X-ray luminescence --- sapphires --- corundum --- in situ oxygen isotopes --- Orosmayo Argentina --- lamprophyre --- secondary ion mass spectrometry (SIMS) --- carbonatite --- gemstones --- corundum --- beryl --- jadeitite --- garnet --- quartz varieties --- Greece --- emeralds --- LA-ICP-MS --- UV-Vis-NIR --- FTIR --- Raman --- PL --- n/a

Wine Traceability

Author:
ISBN: 9783039217687 9783039217694 Year: Pages: 138 DOI: 10.3390/books978-3-03921-769-4 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology --- Biochemistry
Added to DOAB on : 2019-12-09 11:49:16
License:

Loading...
Export citation

Choose an application

Abstract

Wine traceability is a central theme in the current world market where consumers are increasingly demanding the quality and origin of food and drink. The wine production chain and wine composition are generally controlled by different laws (International Organization of Vine and Wine (OIV), European Union (EU), and national governments) and need specific documentation. Nevertheless, wine production is subject to fraud. Consequently, the improvement of the methods applied to verify the origin and quality of wines is very important to protect wine consumers and producers. In this book, eight different papers—six research papers and two reviews—address the topic from different points of view.

Instruments and Methods for Cyclotron Produced Radioisotopes

Authors: ---
ISBN: 9783039282029 9783039282036 Year: Pages: 230 DOI: 10.3390/books978-3-03928-203-6 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: General and Civil Engineering --- Technology (General)
Added to DOAB on : 2020-01-30 16:39:46
License:

Loading...
Export citation

Choose an application

Abstract

The focus of this Special Issue is aimed at enhancing the discussion of Engineering Education, particularly related to technological and professional learning. In the 21st century, students face a challenging demand: they are expected to have the best scientific expertise, but also highly developed social skills and qualities like teamwork, creativity, communication, or leadership. Even though students and teachers are becoming more aware of this necessity, there is still a gap between academic life and the professional world. In this Special Edition Book, the reader can find works tackling interesting topics such as educational resources addressing students’ development of competencies, the importance of final year projects linked to professional environments, and multicultural or interdisciplinary challenges.

Keywords

cyclotron --- PET --- titanium-45 --- unconventional radionuclides --- cyclotron --- targetry --- thermal study --- recycling of [18O]-water --- enrichment grade --- fractional distillation --- azeotropic mixtures --- molecular sieve desiccant --- 165Er --- 52Mn --- irradiation --- separation --- resin --- radiometals --- heavy Rare Earth Elements (hREE) --- liquid targets --- medical cyclotron --- radiometals --- gallium-68 --- copper-64 --- copper-61 --- purification --- disposable kit --- radiopharmaceuticals --- radionuclide production --- target stations --- targetry --- 70 MeV cyclotron --- beam energy --- ion accelerator --- medical cyclotron --- ion source --- filament --- cyclotron --- medical isotopes --- SPECT --- cyclotron --- medical radioisotope production --- radioactive impurities --- cross-section --- stacked-foils --- gamma spectroscopy --- thick target yield --- Radionuclide Yield Calculator --- cyclotron target --- carbon-11 --- recoil escape --- boron nitride nanotubes --- BNNTs --- cyclotrons --- radionuclide production --- solid, liquid and gas targets --- PET --- medical isotopes --- Ga-68 --- solid target --- radioisotopes --- medical radioisotopes --- radioisotope targetry --- solid radioisotope targets --- radioisotope target processing --- medical cyclotrons --- cyclotron --- targetry --- solid target --- metal 3D-printing --- target temperature --- radiometals --- radionuclides --- radioisotopes --- medical radioisotopes --- radioisotope targetry --- solid radioisotope targets --- radioisotope target processing --- medical cyclotrons --- PET --- medical isotopes --- solid target system --- radioisotope production --- Molybdenum-100 --- cyclotron --- molybdenum material recovery --- actinium-225 --- thorium --- spallation --- proton target --- ANSYS --- targeted alpha therapy --- cyclotron --- stack-foil --- monitor reaction --- cyclotron solid target --- radioisotope production --- magnetron sputtering --- thick film deposition --- cyclotron --- powder target --- thermal study --- vortex target --- Gallium-68 --- Technetium-99m --- medical Sc radioisotopes --- radioisotope production --- thick target yield measurements --- cross-section reconstruction --- numerical analysis --- cyclotrons --- targets --- target chemistry --- radioisotopes --- theranostics

Volcanic Plumes.Impacts on the Atmosphere and Insights into Volcanic Processes

Authors: --- ---
ISBN: 9783038976288 Year: Pages: 252 DOI: 10.3390/books978-3-03897-629-5 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General)
Added to DOAB on : 2019-04-05 10:34:31
License:

Loading...
Export citation

Choose an application

Abstract

Volcanoes release plumes of gas and ash to the atmosphere during episodes of passive and explosive behavior. These ejecta have important implications for the chemistry and composition of the troposphere and stratosphere, with the capacity to alter Earth's radiation budget and climate system over a range of temporal and spatial scales. Volcanogenic sulphur dioxide reacts to form sulphate aerosols, which increase global albedo, e.g., by reducing surface temperatures, in addition to perturbing the formation processes and optical properties of clouds. Released halogen species can also deplete stratospheric and tropospheric ozone. Volcanic degassing, furthermore, played a key role in the formation of Earth’s atmosphere, and volcanic plumes can affect air quality, pose hazards to aviation and human health, as well as damage ecosystems. The chemical compositions and emission rates of volcanic plumes are also monitored via a range of direct-sampling and remote-sensing instrumentation, in order to gain insights into subterranean processes, in the respect of the magmatic bodies these volatiles exsolve from. Given the significant role these gases play in driving volcanic activity, e.g., via pressurisation, the study of volcanic plumes is proving to be an increasingly fruitful means of improving our understanding of volcanic systems, potentially in concert with observations from geophysics and contributions from fluid dynamical modelling of conduit dynamics.

Mineral Surface Reactions at the Nanoscale

Author:
ISBN: 9783038978961 9783038978978 Year: Pages: 220 DOI: 10.3390/books978-3-03897-897-8 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Geology --- Earth Sciences
Added to DOAB on : 2019-06-26 08:44:06
License:

Loading...
Export citation

Choose an application

Abstract

Reactions at mineral surfaces are central to all geochemical processes. As minerals comprise the rocks of the Earth, the processes occurring at the mineral–aqueous fluid interface control the evolution of the rocks and hence the structure of the crust of the Earth during processes such as metamorphism, metasomatism, and weathering. In recent years focus has been concentrated on mineral surface reactions made possible through the development of advanced analytical methods such as atomic force microscopy (AFM), advanced electron microscopies (SEM and TEM), phase shift interferometry, confocal Raman spectroscopy, and advanced synchrotron-based applications, to enable mineral surfaces to be imaged and analyzed at the nanoscale. Experiments are increasingly complemented by molecular simulations to confirm or predict the results of these studies. This has enabled new and exciting possibilities to elucidate the mechanisms that govern mineral–fluid reactions. In this Special Issue, “Mineral Surface Reactions at the Nanoscale”, we present 12 contributions that highlight the role and importance of mineral surfaces in varying fields of research.

Preservation of Cultural Heritage and Resources Threatened by Climate Change

Author:
ISBN: 9783039211241 9783039211258 Year: Pages: 186 DOI: 10.3390/books978-3-03921-125-8 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General)
Added to DOAB on : 2019-12-09 11:49:15
License:

Loading...
Export citation

Choose an application

Abstract

With its wide spectrum of data, case studies, monitoring, and experimental and numerical simulation techniques, the multidisciplinary approach of material, environmental, and computer science applied to the conservation of cultural heritage offers several opportunities for the heritage science and conservation community to map and monitor state-of-the-art knowledge on natural and human-induced climate change impacts on cultural heritage—mainly constituted by the built environment—in Europe and Latin America. Geosciences’ Special Issue titled “Preservation of Cultural Heritage and Resources Threatened by Climate Change” was launched to take stock of the existing but still fragmentary knowledge on this challenge, and to enable the community to respond to the implementation of the Paris agreement. These 10 papers exploit a broad range of data derived from preventive conservation monitoring conducted indoors in museums, churches, historical buildings, or outdoors in archeological sites and city centers. Case studies presented in the papers focus on a well-assorted sample of decay phenomena occurring on heritage materials (e.g., surface recession and biomass accumulation on limestone, depositions of pollutant on marble, salt weathering on inorganic building materials, and weathering processes on mortars in many local- to regional-scale study areas in the Scandinavian Peninsula, the United Kingdom, Belgium, France, Italy, Greece, and Panama). Besides monitoring, the methodological approaches showcased include, but are not limited to, original material characterization, decay product characterization, and climate and numerical modelling on material components for assessing environmental impact and climate change effects.

Biological Communities Respond to Multiple Human-Induced Aquatic Environment Change

Authors: ---
ISBN: 9783039285440 / 9783039285457 Year: Pages: 170 DOI: 10.3390/books978-3-03928-545-7 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Environmental Sciences
Added to DOAB on : 2020-06-09 16:38:57
License:

Loading...
Export citation

Choose an application

Abstract

Perturbations linked to the direct and indirect impacts of human activities during the Anthropocene affect the structure and functioning of aquatic ecosystems to varying degrees. Some perturbations involve stress to aquatic life, including soil and water acidification, soil erosion, loss of base cations, release of trace metals/organic compounds, and application of essential nutrients capable of stimulating primary productivity. Superimposed onto these changes, climate warming impacts aquatic environments via altering species’ metabolic processes and by modifying food web interactions. The interaction stressors is difficult to predict because of the differential response of species and taxonomic groups, interacting additively, synergistically, or antagonistically. Whenever different trophic levels respond differently to climate warming, food webs are restructured; yet, the consequences of warming-induced changes for the food web structure and long-term population dynamics of different trophic levels remain poorly understood. Such changes are crucial in lakes, where food web production is mainly due to ectotherms, which are highly sensitive to changes in their surrounding environment. Due to its remarkable physical inertia, including thermal stability, global warming also has a profound effect on groundwater ecosystems. Combining contemporary and palaeo data is essential to understand the degree to which mechanisms of stressors impact on lake biological communities and lake ecosystem functioning. The degree to which alterations can affect aquatic ecosystem structure and functioning also requires functional diversity to be addressed at the molecular level, to reconstruct the role different species play in the transfer of material and energy through the food web. In this issue, we present examples of the impact of different stressors and their interaction on aquatic ecosystems, providing long-term, metabolic, molecular, and paleolimnological analyses.

Listing 1 - 10 of 13 << page
of 2
>>
Sort by
Narrow your search