Physical Sciences and Mathematics Commons^™

Carbon-Based Nanostructured Materials For Energy And Water Purification Applications, Daniel Nde

Theses and Dissertations

High demand of energy consumption and a decline in available water sources are two critical issues our growing world is facing today. There are urgent needs to develop efficient ways to convert and store renewable energy and to remove contaminants from wastewater to obtain clean water. To solve the energy issue, hydrogen production from water splitting using renewable energy is one of the solutions, which calls for highly efficient water-splitting electrocatalysts. To solve the clean water issue, filtration membranes using graphene-based nanostructures have received increased attention. In the first project of this work, we use two approaches to synthesize the …

Photoelectrochemical Sensing Based On Zr-Mofs For Homocysteine Detection, Wen-Xia Dong, Guang-Ming Wen, Bin Liu, Zhong-Ping Li

Journal of Electrochemistry

Due to the independent form of the light source and detection system, photoelectrochemical (PEC) sensor has the advantages of low background, high sensitivity and simple operation. So far, PEC systems have been widely used in the fields including the actual detection of metal ions, biological antibodies or antigens in environmental pollutants. When the photosensitive material is irradiated by a light source with an energy being equal to or greater than its band gap, electrons (e^-) transition occurs from the valence band to the conduction band, leaving a hole (h⁺), at the same time, the generated electron-hole …

The Sonora Substellar Atmosphere Models. Ii. Cholla: A Grid Of Cloud-Free, Solar Metallicity Models In Chemical Disequilibrium For The Jwst Era, Theodora Karalidi, Mark Marley, Jonathan J. Fortney, Caroline Morley, Didier Saumon, Roxana Lupu, Channon Visscher, Richard Freedman

Faculty Work Comprehensive List

Exoplanet and brown dwarf atmospheres commonly show signs of disequilibrium chemistry. In the James Webb Space Telescope (JWST) era, high-resolution spectra of directly imaged exoplanets will allow the characterization of their atmospheres in more detail, and allow systematic tests for the presence of chemical species that deviate from thermochemical equilibrium in these atmospheres. Constraining the presence of disequilibrium chemistry in these atmospheres as a function of parameters such as their effective temperature and surface gravity will allow us to place better constraints on the physics governing these atmospheres. This paper is part of a series of works presenting the Sonora …

Functional Sulfate Electrolytes Enable The Enhanced Cycling Stability Of Nati2(Po4)3/C Anode Material For Aqueous Sodium-Ion Batteries, Shu-Jin Li, Zhi-Kang Cao, Wen-Kai Wang, Xiao-Han Zhang, Xing-De Xiang

Journal of Electrochemistry

Aqueous sodium-ion batteries show promising application in fields of large-scale storage of intermittent renewable energies owing to the earth-abundant sodium resources and incombustible aqueous electrolytes. Primary factors determining whether they can be commercially utilized are low cost and long lifetime. Among current electrode materials, NASICON-type NaTi₂(PO₄)₃ arouses wide interests as an anode material for aqueous sodium-ion batteries as it offers a high specific capacity, fast Na-transport ability and reasonable working potential, however, suffering from insufficient cycling performance caused by severe dissolution of active materials in traditional aqueous electrolytes. In this work, a functional sulfate electrolyte …

Nitrogen-Sulfur Co-Doped Porous Carbon Preparation And Its Application In Lithium-Sulfur Batteries, Gui-Xiang Zhao, Wail Hafiz Zaki Ahmed, Fu-Liang Zhu

Journal of Electrochemistry

In recent years, lithium-sulfur (Li-S) batteries have been considered as a promising candidate for the next generation of energy storage system due to their ultrahigh theoretical capacity (1675 mAh·g^-1) and energy density (2600 Wh·kg^-1). However, the practical application of Li-S batteries is seriously limited by their insulating nature of sulfur, the shuttle effect of polysulfides (LiPSs), and volume expansion during charging and discharging. To overcome those disadvantages, one of the commonly methods is to infiltrate sulfur into porous conductive carbon framework, such as porous carbon, hollow carbon spheres, graphene, carbon nanotubes and some composites of the …

Structure Analysis Of Pemfc Cathode Catalyst Layer, Rui-Qing Wang, Sheng Sui

Journal of Electrochemistry

The sluggish oxygen reduction reaction (ORR) on the cathode of the proton exchange membrane fuel cell (PEMFC) has always been one of the key factors limiting its commercialization. The optimization of the cathode catalytic layer structure plays an important role in improving fuel cell performance and reducing production costs. In this paper, two different catalysts (platinum nanoparticles (Pt-NPs) and platinum nanowires (Pt-NWs)) were prepared by using catalyst coated substrate (CCS) method. By constructing a double-layer catalytic layer structure, we analyzed the effect of different catalytic layer structures by performing a single cell test. The results showed that the dense platinum …

Formation And Morphological Evolution Of Nanoporous Anodized Iron Oxide Films, Jin-Wei Cao, Nan Gao, Zhao-Qing Gao, Chen Wang, Sheng-Yan Shang, Yun-Peng Wang, Hai-Tao Ma

Journal of Electrochemistry

The preparation of iron oxide films with nanoporous structure by anodization has attracted much attention for its potential applications. However, the formation mechanism of porous structure during anodization is still unclear. In this paper, the composition of anodic current during the formation of nanoporous anodized iron oxide film was analyzed in combination with the current density-potential response (I-V curve) and the derivation of Faraday’s law. The results showed that the anodic current consisted of an ionic current (leading to the migration of ions to form oxide) and an electronic current (leading to the oxygen evolution), and the …

Importance Of Haresfoot Clover (Trifolium Arvense) As A Nitrogen Fixer In Semi-Arid Grasslands Of New Zealand, C. C. Boswell, W. L. Lowther, P. R. Espie

IGC Proceedings (1977-2023)

The aim of the study was to determine the distribution of annual haresfoot clover (Trifolium arvense) in a depleted indigenous short tussock grassland catchment in the dry subhumid MacKenzie Basin, South Island, New Zealand. Haresfoot clover was present on all landscapes, and widely distributed on lower sunny aspects, suggesting that it is an important component of the nitrogen cycle in these environments even in the absence of fertiliser application. The study was conducted during an atypically moist summer when a bloom of the annual clover occurred. Nitrogen inputs will vary with landscape and spring/summer rainfall and it is …

The Future For Savanna And Tropical Grasslands: A Latin American Perspective, R. R. Vera

IGC Proceedings (1977-2023)

The objective of the paper is to briefly review the main trends in the tropical lowlands of Latin America and the Caribbean (LAC) with particular emphasis in the neotropical savannas. These tropical native grasslands cover occupy approximately 210 million hectares, and constitute major portions of the territory of Bolivia, Brazil, Colombia, Guyana and Venezuela. Many analysts consider that intensification of their use is a valid alternative to the expansion of the livestock and crop industries into the rainforest.

The evidence reviewed shows that since the late 1980s, the LAC agricultural sector has shown dynamism not seen for many years. Despite …

Ecophysiology And Management Response Of The Subtropical Grasslands Of Southern South America, E. J. Berretta

IGC Proceedings (1977-2023)

The subtropical grasslands of Southern South America (campos) are located approximately in the range of 24° S to 37° S latitude. These grasslands are dominated by C₃ and C₄ grasses, and in a lesser extent to herbaceous plants, shrubs and dispersed trees, with some exceptions in particular regions. Previous to the introduction of large herbivores, at the beginning of the XVII century, like cattle and horses, shrubs and tall grasses dominated the vegetation. Then, associated with greater grazing pressure and partially due to fire, the original campos are maintained, actually in a pseudo-climax herbaceous phase. These native communities …

Goats To Control The Encroachment Of Undesirable Brush And Woody Species In Cattle Pastures, J-M. Luginbuhl, J. T. Green Jr., M. H. Poore, A. C. Conrad

IGC Proceedings (1977-2023)

Field studies were initiated in an abandoned, overgrown 8.4 ha orchard left untouched for 15 years to evaluate the effectiveness of using goats (Capra hircus hircus) to manage undesirable vegetation. Goats alone (G: 30 does/ha) or cattle (Bos taurus) with goats (GC:17 does/ha and 3 steers/ha) were mob-grazed twice a year during four grazing seasons. Multiflora rose (Rosa multiflora Thunb.) canopy area decreased from 12 to 2.5 m² in grazed pastures and multiflora rose live canes were 100% in the control, 0% in G, and only 8% in GC at the completion of the …

Herbaceous Vegetation Dynamic After Cut And Burn Shrub Plants In Southern Brazil, A. M. Girardi-Deiro, M. L. Porto, J. Riboldi

IGC Proceedings (1977-2023)

A savanna area at "Serra do Sudeste" in southern Brazil, was studied during four years to evaluate the influence of cutting and burning shrub plants on dynamic of herbaceous vegetation. The cover of each species in 44 permanent quadrats (0,25 m²) and in each area (cut and burned) was evaluated. The results suggested that grasses and legumes were favored by cutting shrub plants. Burning favored forbs in the first years after disturbance and retarded the development of native forage species desirable for grazing.

Prediction Of Body Fat Percentage Based On Anthropometric Measurements Using Data Mining Approach, Hamsa Amro, Prof. Mohammed Awad

Journal of the Arab American University مجلة الجامعة العربية الامريكية للبحوث

In recent years, heart disease, diabetes, and some types of cancers have been reported as some main causes of death in most countries of the world, and obesity, which is often attributed to excess body fat, is one of the most common risk factors for these diseases. To make the vast amounts of data produced by health care information systems useful to the potential, the researchers applied knowledge discovery through predictive modeling. This study used anthropometric measurements as input data to different data mining techniques to predict body fat percentage. Fisher’s Method of Scoring was used to select the most …

Characterization Of Forage Selected By Cattle On Communal Range In Manhiça, Mozambique, O. Faftine, A. Alage, J. P. Muir

IGC Proceedings (1977-2023)

Forage selection by 10 cattle herds was observed monthly over 2 years on a communal rangeland. Plants grazed were hand-plucked as representative of both species and plant portions being cropped by cattle. Herds were led to green pasture year-round. Nutrient concentration of species and plant portions selected by cattle indicated adequate crude protein and calcium but phosphorus deficiency during the dry season. Well-drained escarpments and uplands were more important during the rains while upland depressions and the Nkomati valley were essential for adequate forage intake during the dry seasons.

Deforestation For Pasture Development – Has It Been Worth It?, W. H. Burrows

IGC Proceedings (1977-2023)

Differing scenarios leading to deforestation for pasture development in savanna (woodland) and closed forest communities in the tropics – sub-tropics are compared and contrasted. Australian and Brazilian examples are highlighted. No simple answer is given to the question of whether deforestation for pasture development has been worth it, since both commercial and non-commercial values have equal validity and need to be taken into account. These issues are addressed in the context of land assigned by governments for agricultural purposes. It is concluded that technology and ecological understanding are now available to maintain sustainable production from converted forest systems. However emphasis …

Back To The Future – Pastoral Land Use In A Forest Land – Sustainability Challenges For The 21St Century, J. Morgan Williams

IGC Proceedings (1977-2023)

To contribute meaningfully to a session entitled “Deforestation” with a proposed paper title of “Trees in Pastoral Zones; Landuse Standards in the 21^st Century” necessitates I carefully define the scope of my contribution. My paper will draw on my experiences as an ecologist working in the pastoral lands of New Zealand in roles that have led me to delve increasingly into what constitutes sustainability (of people, land and economy) for a tiny multicultural nation maturing amidst the remnants of a unique Gondwanaland ecosystem. As New Zealand’s Parliamentary Commissioner for the Environment (PCE) I now examine a very wide range …

Carbon Accumulation In Soils Under Brachiaria Pastures In The Atlantic Forest Region Of The South Of Bahia, Brazil, R. M. Tarré, R. Macedo, R. B. Cantarutti, C. De P. Rezende, J. M. Pereira, E. Ferreira, B. J. R. Alves, S. Urquiaga, R. M. Boddey

IGC Proceedings (1977-2023)

The objective of this study was to investigate the change in carbon stocks in soil following deforestation of the Atlantic forest in the South of Bahia State (Brazil) and replacement with productive pastures of Brachiaria humidicola either in monoculture or with the introduction of the forage legume Desmodium ovalifolium. Carbon stocks in the 0-30 cm layer were 44.5 Mg ha^-1 under the original forest and found to be approximately 42 Mg ha^-1 C 10 years later. At this time pastures of B. humidicola with or without the presence of D. ovalifolium were formed and grazed continuously for …

Potential Role Of Native Bush In The Chaco For Mitigation Of Dryland Salinity In Grassland, A. Glatzle, R. Schultze-Kraft, R. Mitlöhner

IGC Proceedings (1977-2023)

There is a zone of some 3.000.000 ha with an elevated dryland salinity risk in the Paraguayan Chaco due to a shallow saline ground water table. Evidence is shown of the crucial role native bush seems to play in keeping the water table at a low level and reducing therefore the risk of soil salinisation. In this paper a planned field experiment is outlined to define the tolerable level of deforestation and pasture establishment for a sylvopastoral production system in the Chacoan zone prone to dryland salinity.

What Interactive Web Features Are Most Used, Travis Tyler

Experiential Learning Projects

The use of interactive features in websites has become common place on the internet. People use these tools to help navigate and understand the content related to that website. However, due the large variety of websites it can be tricky to understand what features are best to utilize based on the topic of your site. This paper seeks to address this issue by researching how users interact and utilized different features on different websites. Research is gathered via scholarly articles and direct data gathered from volunteers. This data shows users tend to favor more interactive tools to help with navigation, …

Development And Validation Of A New Scale To Assess Air Quality Knowledge (Aqiq), Alessandro Del Ponte, Lina Ang, Lianjun Li, Noah Lim, Wilson Wai San Tam, Wei Jie Seow

Political Science Faculty Articles and Research

Background

Methods

The Circle Of Life: The Mathematics Of Predator-Prey Dynamics, John Butler, Rebecca Brady

Articles

Some animals hunt other animals to feed themselves; these animals are called predators. Animals who are hunted and eaten are known as prey. What do you think would happen if a predator were introduced to an ecosystem where the prey previously lived without fear of being hunted? Would the new predator eat all the prey animals until they go extinct? Actually, the relationship between predator and prey is far more interesting than this. In this article, we show what the predator-prey relationship looks like over time and explain how scientists can make predictions about future population levels, all using basic …

Silver Bow Creek/Butte Area Npl Site, Trec Inc., A Woodard And Curran Company

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Response To Agency Comments Received December 15 On Silver Bow Creek Butte Area Npl Site 2022 Draft Butte Priority Soils Operable Unit Interim Site-Wide Surface Water Monitoring Quality Assurance Project Plan. Consent Decree- Civil Action No. Cv 89-039-Bu-She, Josh Bryson

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

A Mathematical Model For Transport And Growth Of Microbes In Unsaturated Porous Soil, Harihar Khanal, Andrei Ludu, Ramesh Chandra Timsina, Kedar Nath Uprety

Publications

In this work, we develop a mathematical model for transport and growth of microbes by natural (rain) water infiltration and flow through unsaturated porous soil along the vertical direction under gravity and capillarity by coupling a system of advection diffusion equations (for concentration of microbes and their growth-limiting substrate) with the Richards equation. (e model takes into consideration several major physical, chemical, and biological mechanisms. (e resulting coupled system of PDEs together with their boundary conditions is highly nonlinear and complicated to solve analytically. We present both a partial analytic approach towards solving the nonlinear system and finding the main …

A Nanoscale Shape-Discovery Framework Supporting Systematic Investigations Of Shape-Dependent Biological Effects And Immunomodulation, Wei Zhang, Hender Lopez, Luca Boselli, Paolo Bigini, André Perez-Potti, Zengchun Xie, Valentina Castagnola, Qi Cai, Camila P. Silveira, Joao M. De Araujo, Laura Talamini, Nicolò Panini, Giuseppe Ristagno, Martina B. Violatto, Stéphanie Devineau, Marco P. Monopoli, Mario Salmona, Valeria A. Giannone, Sandra Lara, Kenneth A. Dawson, Yan Yan

Articles

Since it is now possible to make, in a controlled fashion, an almost unlimited variety of nanostructure shapes, it is of increasing interest to understand the forms of biological control that nanoscale shape allows. However, a priori rational investigation of such a vast universe of shapes appears to present intractable fundamental and practical challenges. This has limited the useful systematic investigation of their biological interactions and the development of innovative nanoscale shape-dependent therapies. Here, we introduce a concept of biologically relevant inductive nanoscale shape discovery and evaluation that is ideally suited to, and will ultimately become, a vehicle for machine …

Sbc/Butte Area Npl Site Final Bpsou Interim Site-Wide Surface Water Monitoring Qapp 2020 And 2021 Monitoring Period, 10/14/20, Nikia Greene

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Initial Effects Of Deforestation On Herbaceous Species Composition In Grassy Woodlands Of The Northern Tablelands, Nsw Australia, Chris R. Chilcott, N. Reid, R. D. B. Whalley

IGC Proceedings (1977-2023)

Limited information on the initial effects of clearing and thinning on herbaceous vegetation of grassy temperate eucalyptus forests exists. The aim of this investigation is to study the initial changes in species composition following clearing and thinning. A deforestation experiment was established where clearing, thinning of 50% of canopy cover and control treatments were established. In the open-forests, patterns in herbaceous species composition were strongly influenced by the presence of trees, with weeping wheat grass (Microlaena stipoides) dominant, whereas wiregrass (Aristida ramosa) dominated interspaces and canopy gaps. Immediately following clearing, significant changes in the herbaceous species …

The Influence Of Large Animal Diversity In Grazed Ecosystems, M. G. Murray, D. R. Baird

IGC Proceedings (1977-2023)

Field observations in the Serengeti National Park, Tanzania have revealed several modes of grazing system, including migration, sustained-yield grazing and grazing succession which contribute on the one hand to ecological separation of herbivores by habitat choice, but on the other hand to positive association of species on wet season pastures known as hot spots. Drawing from results of experimental field studies, we consider what is known about resource competition and facilitation, the two key ecological processes underlying these grazing systems, and specify the shape of the relationship between species richness and pasture height that is predicted depending on which process …

Grassland Use And Plant Diversity In Grazed Ecosystems, V. A. Deregibus, E. J. Jacobo, O. E. Ansin

IGC Proceedings (1977-2023)

Earth biomes are being deconstructed, through unprecedented rates of species disappearance or invasion (McCann 2000). This, added to the threat of global environmental change and changes in values of a developed society, caused that biodiversity became a topic that has captured the attention of the public as well as the scientific community. Such concern on the importance of biodiversity is based in four basic reasons clearly described by West (1993): (i) morality, that aims for the protection of species; (ii) aesthetics, as people desire to see and appreciate the living parts of nature; (iii) economics and, (iv) the array …

The Effect Of Phosphorus Fertilization On Botanical Composition And Production In Temperate Pastures In Argentina, E. J. Jacobo, A. M. Rodríguez, M. F. Garbulsky, P. Scardoni, V. A. Deregibus

IGC Proceedings (1977-2023)

The objective of this paper is to evaluate floristic changes and above-ground primary production in native grasslands and old pastures dominated by tall fescue (Festuca arundinacea) that were fertilized with different levels of phosphorus. For this, aerial biomass was sequentially harvested from November 1998 to October 1999. Above-ground production of native grassland more than doubled (from 3000 to 7300 kg DM/ha) with the highest level of P through the increment of three naturalized species: the winter annual ryegrass (Lolium multiflorum) and two legumes: white clover (Trifolium repens) and lotus (Lotus corniculatus). In …