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Articles 1 - 20 of 20
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Atmospheric Pco2 Reconstructed Across Five Early Eocene Global Warming Events, Ying Cui, Brian A. Schubert
Atmospheric Pco2 Reconstructed Across Five Early Eocene Global Warming Events, Ying Cui, Brian A. Schubert
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Multiple short-lived global warming events, known as hyperthermals, occurred during the early Eocene (56–52 Ma). Five of these events – the Paleocene–Eocene Thermal Maximum (PETM or ETM1), H1 (or ETM2), H2, I1, and I2 – are marked by a carbon isotope excursion (CIE) within both marine and terrestrial sediments. The magnitude of CIE, which is a function of the amount and isotopic composition of carbon added to the ocean–atmosphere system, varies significantly between marine versus terrestrial substrates. Here we use the increase in carbon isotope fractionation by C3 land plants in response to increased pCO2 to reconcile this difference and …
Tracing Sediment Erosion In The Yangtze River Subaqueous Delta Using Magnetic Methods, Can Ge, Weiguo Zhang, Chenyin Dong, Feng Wang, Huan Feng, Jianguo Qu, Lizhong Yu
Tracing Sediment Erosion In The Yangtze River Subaqueous Delta Using Magnetic Methods, Can Ge, Weiguo Zhang, Chenyin Dong, Feng Wang, Huan Feng, Jianguo Qu, Lizhong Yu
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
We assessed the usefulness of magnetic properties for tracing sediment erosion in a deltaic environment. Surface and core sediments from the Yangtze River subaqueous delta were subjected to magnetic, granulometric, geochemical, and radionuclide analyses. Based on magnetic properties and particle size, the surface sediments can be divided into three groups. Groups I and II have a similar particle size distribution and geochemical composition, but the former has higher values of magnetic susceptibility (χ) and saturation isothermal remanent magnetization (SIRM). We interpret Group I as consisting of modern sediments, while Group II represents previously buried sediments that have undergone significant reductive …
Global Capacity, Potentials And Trends Of Solid Waste Research And Management, Michael A. Nwachukwu, Mersky Ronald, Huan Feng
Global Capacity, Potentials And Trends Of Solid Waste Research And Management, Michael A. Nwachukwu, Mersky Ronald, Huan Feng
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
In this study, United States, China, India, United Kingdom, Nigeria, Egypt, Brazil, Italy, Germany, Taiwan, Australia, Canada and Mexico were selected to represent the global community. This enabled an overview of solid waste management worldwide and between developed and developing countries. These are countries that feature most in the International Conference on Solid Waste Technology and Management (ICSW) over the past 20 years. A total of 1452 articles directly on solid waste management and technology were reviewed and credited to their original country of research. Results show significant solid waste research potentials globally, with the United States leading by 373 …
Chasing Boundaries And Cascade Effects In A Coupled Barrier-Marsh-Lagoon System, Jorge Lorenzo Trueba, Giulio Mariotti
Chasing Boundaries And Cascade Effects In A Coupled Barrier-Marsh-Lagoon System, Jorge Lorenzo Trueba, Giulio Mariotti
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The long-term dynamic evolution of an idealized barrier-marsh-lagoon system experiencing sea-level rise is studied by coupling two existing numerical models. The barrier model accounts for the interaction between shoreface dynamics and overwash flux, which allows the occurrence of barrier drowning. The marsh-lagoon model includes both a backbarrier marsh and an interior marsh, and accounts for the modification of the wave regime associated with changes in lagoon width and depth. Overwash, the key process that connects the barrier shoreface with the marsh-lagoon ecosystems, is formulated to account for the role of the backbarrier marsh. Model results show that a number of …
Valuing Visitor Services And Access To Protected Areas: The Case Of Nyungwe National Park In Rwanda, Pankaj Lal, Bernabas Wolde, Michel Masozera, Pralhad Burli, Janaki Alavalapati, Aditi Ranjan, Jensen Montambault, Onil Banerjee, Thomas Ochuodho, Rodrigue Mugabo
Valuing Visitor Services And Access To Protected Areas: The Case Of Nyungwe National Park In Rwanda, Pankaj Lal, Bernabas Wolde, Michel Masozera, Pralhad Burli, Janaki Alavalapati, Aditi Ranjan, Jensen Montambault, Onil Banerjee, Thomas Ochuodho, Rodrigue Mugabo
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Policymakers and recreation site managers use changes in fee structure, either introducing park entrance fees or increasing existing ones, to generate revenues, improve services, and reduce damages associated with over-use. Increase in park usage fee, however, can make the park inaccessible to certain segments of tourists. Understanding park users' response to changes in fees and its implication on park use equity is, thus, important to achieving a park's full potential in a socially and environmentally responsible way. This information is crucial especially for developing countries, where the issue has received relatively less attention and national park systems are chronically underfunded. …
Microfeatures Of Modern Sea-Ice-Rafted Sediment And Implications For Paleo-Sea-Ice Reconstructions, Kristen E. St. John, Sandra Passchier, Brooke Tantillo, Dennis Darby, Lance Kearns
Microfeatures Of Modern Sea-Ice-Rafted Sediment And Implications For Paleo-Sea-Ice Reconstructions, Kristen E. St. John, Sandra Passchier, Brooke Tantillo, Dennis Darby, Lance Kearns
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Distinguishing sea-ice-rafted debris (SIRD) from iceberg-rafted debris is crucial to an interpretation of ice-rafting history; however, there are few paleo-sea-ice proxies. This study characterizes quartz grain microfeatures of modern SIRD from the Arctic Ocean, and compares these results with microfeatures from representative glacial deposits to potentially differentiate SIRD from ice-rafted sediments which have been recently subjected to glacial processes. This allows us to evaluate the use of grain microfeatures as a paleo-sea-ice proxy. SIRD grains were largely subrounded, with medium relief, pervasive silica dissolution and a high abundance of breakage blocks and microlayering. The glacial grains were more angular, with …
Urban Agglomeration: An Evolving Concept Of An Emerging Phenomenon, Chuanglin Fang, Danlin Yu
Urban Agglomeration: An Evolving Concept Of An Emerging Phenomenon, Chuanglin Fang, Danlin Yu
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Urban agglomeration is a highly developed spatial form of integrated cities. It occurs when the relationships among cities shift from mainly competition to both competition and cooperation. Cities are highly integrated within an urban agglomeration, which renders the agglomeration one of the most important carriers for global economic development. Studies on urban agglomerations have increased in recent decades. In the research community, a consensus with regard to what an urban agglomeration is, how an urban agglomeration is delineated in geographic space, what efficient models for urban agglomeration management are, etc. is not reached. The current review examines 32,231 urban agglomeration-related …
Oceanic Circulation Changes During Early Pliocene Marine Ice-Sheet Instability In Wilkes Land, East Antarctica, Melissa A. Hansen, Sandra Passchier
Oceanic Circulation Changes During Early Pliocene Marine Ice-Sheet Instability In Wilkes Land, East Antarctica, Melissa A. Hansen, Sandra Passchier
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
In the Southern Ocean, unconstrained Westerlies allow for intense mixing between deep waters and the atmosphere. How this system interacts with Antarctic ice sheets and the global ocean circulation is poorly understood due to a paucity of data. The poor abundance and preservation of foraminiferal carbonate in ice-proximal sediments is a major challenge in high-latitude paleoceanography. A new approach is to examine a sediment geochemical record of changing paleoproductivity and sediment redox environment that can be tied to changes in water mass properties. This study focuses on the paleoceanography of the George V Land margin between ~4.7 and 4.3 Ma. …
A Sensitivity Study Of The Impact Of Dynamic Vegetation On Simulated Future Climate Change Over Southern Europe And The Mediterranean, Clement Alo, Emmanouil N. Anagnostou
A Sensitivity Study Of The Impact Of Dynamic Vegetation On Simulated Future Climate Change Over Southern Europe And The Mediterranean, Clement Alo, Emmanouil N. Anagnostou
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Recent projections of climate change from general circulation and regional climate models over southern Europe and the Mediterranean basin show strong warming and pronounced decrease in precipitation over large portion of the region, especially in the summer. While the role of vegetation in modulating the region's climate is widely recognized, most, if not all, of these climate change projections do not account for the response of the dynamic biosphere to the potential climate changes. In this study we investigate the role of climate–vegetation interactions in a regional climate model (RegCM3) linked to a dynamic vegetation model (CLM-DGVM). High spatial resolution …
An Antarctic Stratigraphic Record Of Stepwise Ice Growth Through The Eocene-Oligocene Transition, Sandra Passchier, Daniel J. Ciarletta, Triantafilo E. Miriagos, Peter K. Bijl, Steven M. Bohaty
An Antarctic Stratigraphic Record Of Stepwise Ice Growth Through The Eocene-Oligocene Transition, Sandra Passchier, Daniel J. Ciarletta, Triantafilo E. Miriagos, Peter K. Bijl, Steven M. Bohaty
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Earth’s current icehouse phase began ∼34 m.y. ago with the onset of major Antarctic glaciation at the Eocene-Oligocene transition. Changes in ocean circulation and a decline in atmospheric greenhouse gas levels were associated with stepwise cooling and ice growth at southern high latitudes. The Antarctic cryosphere plays a critical role in the ocean-atmosphere system, but its early evolution is still poorly known. With a near-field record from Prydz Bay, Antarctica, we demonstrate that Antarctic ice growth was stepwise and had an earlier onset than previously suggested. Prydz Bay lies downstream of a major East Antarctic Ice Sheet drainage system, and …
Nutrient Fluxes Across Sediment-Water Interface In Bohai Bay Coastal Zone, China, Di Mu, Dekui Yuan, Huan Feng, Fangwei Xing, Fang Yenn Teo, Shuangzhao Li
Nutrient Fluxes Across Sediment-Water Interface In Bohai Bay Coastal Zone, China, Di Mu, Dekui Yuan, Huan Feng, Fangwei Xing, Fang Yenn Teo, Shuangzhao Li
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Sediment cores and overlying water samples were collected at four sites in Tianjin Coastal Zone, Bohai Bay, to investigate nutrient (N, P and Si) exchanges across the sediment-water interface. The exchange fluxes of each nutrient species were estimated based on the porewater profiles and laboratory incubation experiments. The results showed significant differences between the two methods, which implied that molecular diffusion alone was not the dominant process controlling nutrient exchanges at these sites. The impacts of redox conditions and bioturbation on the nutrient fluxes were confirmed by the laboratory incubation experiments. The results from this study showed that the nutrient …
Nanoscale Measurement Of Trace Element Distributions In Spartina Alterniflora Root Tissue During Dormancy, Huan Feng, Yu Qian, J. Kirk Cochran, Qingzhi Zhu, Wen Hu, Hanfei Yan, Li Li, Xiaojing Huang, Yong S. Chu, Houjun Liu, Shinjae Yoo, Chang Jun Liu
Nanoscale Measurement Of Trace Element Distributions In Spartina Alterniflora Root Tissue During Dormancy, Huan Feng, Yu Qian, J. Kirk Cochran, Qingzhi Zhu, Wen Hu, Hanfei Yan, Li Li, Xiaojing Huang, Yong S. Chu, Houjun Liu, Shinjae Yoo, Chang Jun Liu
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
This paper reports a nanometer-scale investigation of trace element (As, Ca, Cr, Cu, Fe, Mn, Ni, S and Zn) distributions in the root system Spartina alterniflora during dormancy. The sample was collected on a salt marsh island in Jamaica Bay, New York, in April 2015 and the root was cross-sectioned with 10 μm resolution. Synchrotron X-ray nanofluorescence was applied to map the trace element distributions in selected areas of the root epidermis and endodermis. The sampling resolution was 60 nm to increase the measurement accuracy and reduce the uncertainty. The results indicate that the elemental concentrations in the epidermis, outer …
Sedimentary Exhalative Origin For Magnetite Deposits Of The New Jersey Highlands, Peter Matt, Wayne Powell, Richard Volkert, Matthew Gorring, Al Johnson
Sedimentary Exhalative Origin For Magnetite Deposits Of The New Jersey Highlands, Peter Matt, Wayne Powell, Richard Volkert, Matthew Gorring, Al Johnson
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The New Jersey Highlands and contiguous Hudson (New York) Highlands host hundreds of small, worked-out magnetite mines, and the major zinc-oxide deposits of Franklin and Sterling Hill. The origin of the magnetite ore remains controversial. Two temporally distinct genetic models have been proposed for magnetite: (1) a pre-Ottawan, sedimentary exhalative model in which ores were deposited on the seafloor as precipitates from iron-enriched hydrothermal fluids; (2) a late-Ottawan, fluid alteration model in which the current mineral composition of ores was derived from Fe-rich, alkaline fluids, associated with late episodes of granitic plutonism (low-Ti Kiruna-type deposits), or in which deposits derived …
Addressing Harmful Algal Blooms (Habs) Impacts With Ferrate(Vi)Simultaneous Removal Of Algal Cells And Toxins For Drinking Water Treatment, Yang Deng, Meiyin S Wu, Huiqin Zhang, Lei Zheng, Yaritza Acosta, Tsung Ta D. Hsu
Addressing Harmful Algal Blooms (Habs) Impacts With Ferrate(Vi)Simultaneous Removal Of Algal Cells And Toxins For Drinking Water Treatment, Yang Deng, Meiyin S Wu, Huiqin Zhang, Lei Zheng, Yaritza Acosta, Tsung Ta D. Hsu
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Although ferrate(VI) has long been recognized as a multi-purpose treatment agent, previous investigations regarding ferrate(VI) for addressing harmful algal blooms (HABs) impacts in drinking water treatment only focused on a single HAB pollutant (e.g. algal cells or algal toxins). Moreover, the performance of ferrate(VI)-driven coagulation was poorly investigated in comparison with ferrate(VI) oxidation, though it has been widely acknowledged as a major ferrate(VI) treatment mechanism. We herein reported ferrate(VI) as an emerging agent for simultaneous and effective removal of algal cells and toxins in a simulated HAB-impacted water. Ferrate(VI)-driven oxidation enabled algal cell inactivation and toxin decomposition. Subsequently, Fe(III) from …
Forestland Owners’ Willingness To Consider Multiple Ways Of Supplying Biomass Simultaneously: Implications For Biofuel Incentive Policies, Bernabas Wolde, Pankaj Lal, Pralhad Burli
Forestland Owners’ Willingness To Consider Multiple Ways Of Supplying Biomass Simultaneously: Implications For Biofuel Incentive Policies, Bernabas Wolde, Pankaj Lal, Pralhad Burli
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Because socioeconomic based approaches account for relevant limiting and motivating factors, they provide a more realistic measurement of forestland owners’ willingness to supply biomass for bioenergy production- information useful to policy makers in setting production targets and in designing relevant incentive programs. Although forestland owners can supply biomass using different means, including supplying biomass from existing stands and changing land use to establish feedstock plantation, among others, previous studies mostly focus only on a given way of supplying biomass at a time. This produces incomplete information that adversely affects its use. By presenting survey takers in Virginia and Texas three …
Influence And Interaction Of Iron And Cadmium On Photosynthesis And Antioxidative Enzymes In Two Rice Cultivars, Houjun Liu, Chengxin Zhang, Junmei Wang, Chongjun Zhou, Huan Feng, Manoj D. Mahajan, Xiaori Han
Influence And Interaction Of Iron And Cadmium On Photosynthesis And Antioxidative Enzymes In Two Rice Cultivars, Houjun Liu, Chengxin Zhang, Junmei Wang, Chongjun Zhou, Huan Feng, Manoj D. Mahajan, Xiaori Han
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
In this study, a soil pot experiment was conducted to investigate the changes in photosynthesis and antioxidative enzymes in two rice varieties (Shendao 6 and Shennong 265) supplied with iron (Fe), cadmium (Cd), and Fe and Cd together. The concentrations of Fe and Cd in the soil were 0, 1.0 g Fe·kg−1and 0, 2.0 mg Cd·kg−1, respectively. Photosynthetic indices and antioxidative enzyme activities were recorded at different rice growth stages. At the early stage, Cd showed a transient stimulatory effect on the photosynthetic rate of Shennong 265. For Shendao 6, however, Cd showed a transient stimulatory effect on photosynthetic rate, …
Natural And Human-Induced Variability In Barrier-Island Response To Sea Level Rise, Jennifer Miselis, Jorge Lorenzo Trueba
Natural And Human-Induced Variability In Barrier-Island Response To Sea Level Rise, Jennifer Miselis, Jorge Lorenzo Trueba
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Storm-driven sediment fluxes onto and behind barrier islands help coastal barrier systems keep pace with sea level rise (SLR). Understanding what controls cross-shore sediment flux magnitudes is critical for making accurate forecasts of barrier response to increased SLR rates. Here, using an existing morphodynamic model for barrier island evolution, observations are used to constrain model parameters and explore potential variability in future barrier behavior. Using modeled drowning outcomes as a proxy for vulnerability to SLR, 0%, 28%, and 100% of the barrier is vulnerable to SLR rates of 4, 7, and 10 mm/yr, respectively. When only overwash fluxes are increased …
Chemical Oxidation For Mitigation Of Uv-Quenching Substances (Uvqs) From Municipal Landfill Leachate: Fenton Process Versus Ozonation, Chanil Jung, Yang Deng, Renzun Zhao, Kevin Torrens
Chemical Oxidation For Mitigation Of Uv-Quenching Substances (Uvqs) From Municipal Landfill Leachate: Fenton Process Versus Ozonation, Chanil Jung, Yang Deng, Renzun Zhao, Kevin Torrens
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
UV-quenching substance (UVQS), as an emerging municipal solid waste (MSW)-derived leachate contaminant, has a potential to interfere with UV disinfection when leachate is disposed of at publicly owned treatment works (POTWs). The objective of this study was to evaluate and compare two chemical oxidation processes under different operational conditions, i.e. Fenton process and ozonation, for alleviation of UV254 absorbance of a biologically pre-treated landfill leachate. Results showed that leachate UV254 absorbance was reduced due to the UVQS decomposition by hydroxyl radicals (·OH) during Fenton treatment, or by ozone (O3) and ·OH during ozonation. Fenton process exhibited a better treatment performance …
Heterotrophic Bacterial Leaching Of Zinc And Arsenic From Artificial Adamite, Marek Kolenčík, Hana Vojtková, Martin Urík, Mária Čaplovičová, Jaromír Pištora, Michael Cada, Aneta Babičová, Huan Feng, Yu Qian, Illa Ramakanth
Heterotrophic Bacterial Leaching Of Zinc And Arsenic From Artificial Adamite, Marek Kolenčík, Hana Vojtková, Martin Urík, Mária Čaplovičová, Jaromír Pištora, Michael Cada, Aneta Babičová, Huan Feng, Yu Qian, Illa Ramakanth
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Artificial adamite [Zn2(AsO4)(OH)] is a convenient structural model because it is isostructural with other rock-forming minerals in secondary ore deposits formed in cementation zones. Microbial activity in these zones accelerates mineral biogeochemical deterioration and metal release, and our results confirmed that Pseudomonas, Rhodococcus and Cupriavidus strains accelerate adamite leaching by 10 to 465 times compared to controls. Here, the Pseudomonas chlororaphis ZK-1 bacterial strain in a static 42-day cultivation proved more effective than Rhodococcus and Cupriavidus by leaching over 90% arsenic and 10% zinc from adamite in one-step in vitro. We evaluated adamite with the VESTA visualization system for electronic …
Dam Removal In The Usa: Effects On River Water Quality, Michael A. Kruge
Dam Removal In The Usa: Effects On River Water Quality, Michael A. Kruge
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Dam removal decisions should ideally be made after a thorough cost-benefit analysis. If dam obsolescence, structural safety, harm to fisheries, maintenance costs, and reservoir eutrophication are among the primary concerns, decommissioning would likely be favored. On the other hand, dams provide considerable benefits including water storage for agricultural and urban consumption, renewable electricity generation, support of navigational canal systems, flood control, and lakes for recreation. Because of these competing factors and interests, dam removal decision-making in the United States is often a slow process fraught with controversy, as in the case of the Klamath River.
Dams provided mechanical water power …