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Full-Text Articles in Physical Sciences and Mathematics

Solar Cells, D. Venkataraman Jan 2019

Solar Cells, D. Venkataraman

Science and Engineering Saturday Seminars

Solar cells convert the sun's energy into electrical energy. In this workshop, I will discuss the processes involved in solar cell and various types of solar cells that are being developed as an alternative to silicon solar cells. I will also demonstrate how students can build a solar cell from readily available materials.


The Analysis And Deployment Of A Fully Open Monitoring System In The Sri Lankan Deduroya Basin: The 4onse Project, Massimiliano Cannata, Daniele Strigaro, Imran Shahid, Rangajeewa Ratnayake, B.H. Sudantha Jul 2018

The Analysis And Deployment Of A Fully Open Monitoring System In The Sri Lankan Deduroya Basin: The 4onse Project, Massimiliano Cannata, Daniele Strigaro, Imran Shahid, Rangajeewa Ratnayake, B.H. Sudantha

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

The 4onse project studies non-conventional monitoring systems fully based on open technologies (hardware, standard protocols, software and data) for the management of resources and natural hazards in developing countries. After the design of hydro-meteorological stations and software for the collection, management and distribution of data, the study involves the installation of 30 stations in the Deduroya Oya river basin in Sri Lanka. The system will be analysed to fully understand the real cost of ownership, data quality and applicability in real situations. If properly validated, these systems can provide an alternative solution, effective and sustainable for the protection of property ...


Qgis Approach To Extract Fluvial Terraces For Archaeological Purposes Using Remote Sensing Data, Lia Duarte, Alberto Gomes, Ana Cláudia Teodoro, Sérgio Monteiro-Rodrigues Jul 2018

Qgis Approach To Extract Fluvial Terraces For Archaeological Purposes Using Remote Sensing Data, Lia Duarte, Alberto Gomes, Ana Cláudia Teodoro, Sérgio Monteiro-Rodrigues

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

Fluvial terraces, normally defining flattened surfaces are significant geomorphic features that explains the presence of rivers at high altitudes and constitute the remains of the old river along the valley. In Iberia, many of these terraces preserve Paleolithic artifacts and document the presence of the first human communities. Nowadays, the increasing use of Free and Open Source Software (FOSS) provides the opportunity to analyze and test different approaches to study these geomorphological features. According to the literature, several algorithms from open source GIS software have been used, such as Geographic Resources Analysis Support System (GRASS) GIS. In the recent versions ...


Semantic Markup For Geographic Web Maps In Html, Malte Reißig Jan 2018

Semantic Markup For Geographic Web Maps In Html, Malte Reißig

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

In the recent years more and more geographical web maps have been developed and published on the Open Web Platform. Technically this has turned all variants of these maps into documents of the Hypertext Markup Language (HTML) making them appear to us naturally as graph-like and semi-structured data. In this dispute with geographical web maps and HTML we draw on the notion of so called “map mashups”. Requiring an alternative model and definition of what such a map is, our research allows us to build and refine supportive technology which helps us in analyzing and interpreting information map makers code ...


Three-Dimensional Variations Of The Slab Geometry Correlate With Earthquake Distributions At The Cascadia Subduction System, Haiying Gao Jan 2018

Three-Dimensional Variations Of The Slab Geometry Correlate With Earthquake Distributions At The Cascadia Subduction System, Haiying Gao

Geosciences Department Faculty Publication Series

Significant along-strike variations of seismicity are observed at subduction zones, which are strongly influenced by physical properties of the plate interface and rheology of the crust and mantle lithosphere. However, the role of the oceanic side of the plate boundary on seismicity is poorly understood due to the lack of offshore instrumentations. Here tomographic results of the Cascadia subduction system, resolved with full-wave ambient noise simulation and inversion by integrating dense offshore and onshore seismic datasets, show significant variations of the oceanic lithosphere along strike and down dip from spreading centers to subduction. In central Cascadia, where seismicity is sparse ...


Persistent Radical Anion Polymers Based On Naphthalenediimide And A Vinylene Spacer, Sashi Debnath, Connor J. Boyle, Dongming Zhou, Bryan M. Wong, Kevin R. Kittilstved, Dhandapani Venkataraman Jan 2018

Persistent Radical Anion Polymers Based On Naphthalenediimide And A Vinylene Spacer, Sashi Debnath, Connor J. Boyle, Dongming Zhou, Bryan M. Wong, Kevin R. Kittilstved, Dhandapani Venkataraman

Chemistry Department Faculty Publication Series

Persistent n-doped conjugated polymers were achieved by doping the electron accepting PDNDIV and PFNDIVpolymers with ionic (TBACN) or neutral (TDAE) dopants. The great electron affinities, as indicated by the low LUMO levels of PDNDIV (−4.09 eV) and PFNDIV (−4.27 eV), facilitated the chemical reduction from either TBACN or TDAE. The low-lying LUMOs of the neutral polymers PDNDIV and PFNDIV were achieved by incorporation of vinylene spacers between the electron poor NDI units to increase the conjugation length without the use of an electron donor, and this was lowered further by an electron-withdrawing fluorinated N-substituent on the NDI ...


Data For "Interplay Between Ion Transport, Applied Bias And Degradation Under Illumination In Hybrid Perovskite P-I-N Devices", Emily C. Smith, Christie L.C. Ellis, Hamza Javaid, Lawrence A. Renna, Yao Liu, Thomas P. Russell, Monojit Bag, Dhandapani Venkataraman Jan 2018

Data For "Interplay Between Ion Transport, Applied Bias And Degradation Under Illumination In Hybrid Perovskite P-I-N Devices", Emily C. Smith, Christie L.C. Ellis, Hamza Javaid, Lawrence A. Renna, Yao Liu, Thomas P. Russell, Monojit Bag, Dhandapani Venkataraman

Data and Datasets

We studied ion transport in hybrid organic inorganic perovskite p-i-n devices as a function of applied bias under device operating conditions. Using electrochemical impedance spectroscopy (EIS) and equivalent circuit modeling, we elucidated various resistive and capacitive elements in the device. We show that ion migration is predictably influenced by a low applied forward bias, characterized by an increased capacitance at the hole transporting (HTM) and electron transporting material (ETM) interfaces, as well as through the bulk. However, unlike observations in n-i-p devices, we found that there is a capacitive discharge leading to ion redistribution in the bulk at high forward ...


Evolving Black Holes In Inflation, Ruth Gregory, David Kastor, Jennie Traschen Jan 2018

Evolving Black Holes In Inflation, Ruth Gregory, David Kastor, Jennie Traschen

Physics Department Faculty Publication Series

We present an analytic, perturbative solution to the Einstein equations with a scalar field that describes dynamical black holes in a slow-roll inflationary cosmology. We show that the metric evolves quasi-statically through a sequence of Schwarzschild–de Sitter like metrics with time dependent cosmological constant and mass parameters, such that the cosmological constant is instantaneously equal to the value of the scalar potential. The areas of the black hole and cosmological horizons each increase in time as the effective cosmological constant decreases, and the fractional area increase is proportional to the fractional change of the cosmological constant, times a geometrical ...


3' End Additions By T7 Rna Polymerase Are Rna Self-Templated, Distributive And Diverse In Character––Rna-Seq Analyses, Yasaman Gholamalipour, Aruni K. Mudiyanselage, Craig T. Martin Jan 2018

3' End Additions By T7 Rna Polymerase Are Rna Self-Templated, Distributive And Diverse In Character––Rna-Seq Analyses, Yasaman Gholamalipour, Aruni K. Mudiyanselage, Craig T. Martin

Chemistry Department Faculty Publication Series

Synthetic RNA is widely used in basic science, nanotechnology and therapeutics research. The vast majority of this RNA is synthesized in vitro by T7 RNA polymerase or one of its close family members. However, the desired RNA is generally contaminated with products longer and shorter than the DNA-encoded product. To better understand these undesired byproducts and the processes that generate them, we analyze in vitro transcription reactions using RNA-Seq as a tool. The results unambiguously confirm that product RNA rebinds to the polymerase and self-primes (in cis) generation of a hairpin duplex, a process that favorably competes with promoter driven ...


Mapping Sandbars In The Connecticut River Watershed Through Aerial Images For Floodplain Conservation, Bogumila Backiel Jan 2018

Mapping Sandbars In The Connecticut River Watershed Through Aerial Images For Floodplain Conservation, Bogumila Backiel

Masters Theses

Active geomorphic features of rivers like sandbars provide habitat for endangered and threatened riparian plant and animal species. However, human development has altered flow and sediment regimes, thus impairing formation of sandbars and islands. Large scale mapping of the fluvial geomorphology in river ecosystems like the Connecticut River is are necessary to understand the dynamics of these features and preserve habitat. Orthophotographs from 2012 from United States Department of Agriculture's Farm Service Agency (FSA), National Agriculture Imagery Program (NAIP) were used to develop a model in ArcGIS Pro to identify fluvial geomorphic features in the Connecticut River and 12 ...


Designing Sustainable Landscapes: Biomass Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Biomass Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

Vegetation biomass is an effective descriptor of the net primary productivity of an ecosystem. As such, it is a fundamental component of the ecosystem's trophic dynamics. In addition, vegetation biomass is an effective proxy for the successional development (or seral stage) of vegetation following a disturbance. Biomass is one of several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). Specifically, biomass measures the estimated above-ground live biomass (Mg/ha) of undeveloped forested (including forested wetlands) cells in 2010 based primarily on a spectral ...


Umass Amherst Energy Consumption, Ghg Emissions, Energy Intensity From 2002-2017, Ezra Small Jan 2018

Umass Amherst Energy Consumption, Ghg Emissions, Energy Intensity From 2002-2017, Ezra Small

Campus Data

Data spreadsheet of GHG emissions, fuel consumption, and energy intensity for UMass Amherst between Fiscal Years 2002 to 2017.


Fy 2018 Umass Amherst Electricity Data By Building, Ezra Small Jan 2018

Fy 2018 Umass Amherst Electricity Data By Building, Ezra Small

Campus Data

Each year, UMass Amherst Utilities publishes this spreadsheet which has the monthly and annual building energy consumption of each metered building on campus. Cost data and production vs. purchased electricity data are also provided.


Fy 2018 Umass Amherst Waste Management Report, Ezra Small Jan 2018

Fy 2018 Umass Amherst Waste Management Report, Ezra Small

Campus Data

Each year the Office of Waste Management publishes this report which totals recycling and refuse data for the campus.


Fy 2018 Umass Amherst Water & Steam Data By Building, Ezra Small Jan 2018

Fy 2018 Umass Amherst Water & Steam Data By Building, Ezra Small

Campus Data

Each year, UMass Amherst Utilities publishes this spreadsheet which has the monthly and annual building water and steam consumption of each metered building on campus.


Streamwise Flow-Induced Oscillations Of Bluff Bodies - The Influence Of Symmetry Breaking, Tyler Gurian Jan 2018

Streamwise Flow-Induced Oscillations Of Bluff Bodies - The Influence Of Symmetry Breaking, Tyler Gurian

Masters Theses

The influence of symmetry breaking on the flow induced oscillations of bluff bodies in the steamwise direction is studied. First, a series of experiments is conducted on a one-degree-of-freedom circular cylinder allowed to exhibit pure translational motion in the streamwise direction over a range of reduced velocities, 1.4 < U* < 4.4, corresponding to a Reynolds number range of 970 < Re < 3370. Two distinct regions of displacements were observed in reduced velocity ranges of 1.6 < U* < 2.5 and 2.75 < U* < 3.85. Measured force coefficients in the drag and lift direction were examined, along with the wake visualization, through the range of reduced velocities, to infer the resulting wake modes. A new Alternating Symmetric (AS) mode was found. This transition from symmetric to AS shedding occurred near the end of the first region of response. Similar tests were run with a square prism in the parameter space of 2.4 < U* < 5.8 and 757 < Re < 1900 over angles of incidence of 0° ≤ α ≤ 45°. A distinct region of lock-in is observed for α = 0°, 2.5°, 5°, 7.5° over 3.2 < U* < 5.4 for α = 0°, and decreasing with increasing α. The wake structures were found to be roughly symmetric for α = 0°, but transitioned towards asymmetry with ...


Plants, Parasites, And Pollinators: The Effects Of Medicinal Pollens On A Common Gut Parasite In Bumble Bees, George Locascio Jan 2018

Plants, Parasites, And Pollinators: The Effects Of Medicinal Pollens On A Common Gut Parasite In Bumble Bees, George Locascio

Masters Theses

Declines in several pollinator species are due to a variety of factors, including pathogens. Incorporating pollinator-friendly plant species into wild and agricultural habitats could reduce the stress of pathogens if food sources act medicinally against pathogens. Previous research demonstrated one domesticated sunflower cultivar (Helianthus annuus) can dramatically reduce a gut pathogen (Crithidia bombi) of the common eastern bumble bee, Bombus impatiens. To ascertain the breadth of this medicinal trait, we tested whether pollen from several H. annuus cultivars and four relatives could also reduce C. bombi infections in B. impatiens. We also investigated whether timing of exposure to sunflower pollen ...


Real-Time Dengue Forecasting In Thailand: A Comparison Of Penalized Regression Approaches Using Internet Search Data, Caroline Kusiak Jan 2018

Real-Time Dengue Forecasting In Thailand: A Comparison Of Penalized Regression Approaches Using Internet Search Data, Caroline Kusiak

Masters Theses

Dengue fever affects over 390 million people annually worldwide and is of particu- lar concern in Southeast Asia where it is one of the leading causes of hospitalization. Modeling trends in dengue occurrence can provide valuable information to Public Health officials, however many challenges arise depending on the data available. In Thailand, reporting of dengue cases is often delayed by more than 6 weeks, and a small fraction of cases may not be reported until over 11 months after they occurred. This study shows that incorporating data on Google Search trends can improve dis- ease predictions in settings with severely ...


Designing Sustainable Landscapes: Aquatic Barriers Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Aquatic Barriers Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

Aquatic barriers is one of several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). Aquatic barriers measures the relative degree to which road-stream crossings (i.e., bridges and culverts) and dams may physically impede upstream and downstream movement of aquatic organisms, particularly fish. It is derived from a custom algorithm (see below for details) applied to dams and derived road-stream crossings. Briefly, each dam has an aquatic barrier score based either on dam height or attributes indicating whether the dam has a partial/complete ...


Regional Invasive Species & Climate Change Management Challenge: Preparing For Sleeper Species, Bethany A. Bradley, Evelyn Beaury, Emily J. Fusco, Brittany Laginhas, Toni Lyn Morelli, Valerie Pasquarella Jan 2018

Regional Invasive Species & Climate Change Management Challenge: Preparing For Sleeper Species, Bethany A. Bradley, Evelyn Beaury, Emily J. Fusco, Brittany Laginhas, Toni Lyn Morelli, Valerie Pasquarella

Environmental Conservation Educational Materials

Many naturalized non-native species never become invasive and generally are not prioritized for management due to limited resources. However, climate change could enhance the success of these species, causing some to become invasive. Therefore, we need to reassess the current pool of naturalized species to identify and prioritize management of ‘sleeper’ species.


Regional Invasive Species & Climate Change Management Challenge: Why Native? Benefits Of Planting Native Species In A Changing Climate, Emily J. Fusco, Jenica M. Allen, Evelyn M. Beaury, Michelle R. Jackson, Brittany B. Laginhas, Toni Lyn Morelli, Bethany A. Bradley Jan 2018

Regional Invasive Species & Climate Change Management Challenge: Why Native? Benefits Of Planting Native Species In A Changing Climate, Emily J. Fusco, Jenica M. Allen, Evelyn M. Beaury, Michelle R. Jackson, Brittany B. Laginhas, Toni Lyn Morelli, Bethany A. Bradley

Environmental Conservation Educational Materials

Yards host a variety of native and non-native plants. It is easy to assume all plants play a similar role in supporting wildlife, but native plants dramatically increase the diversity of bees, butterflies, birds and other native animals. Additionally, non-native plants can become invasive or support invasive pests. Native plants increase biodiversity and reduce risks associated with invasive species, which supports resilient ecosystems in the face of climate change.


Designing Sustainable Landscapes: Development Settings Variable, Hard Development Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Development Settings Variable, Hard Development Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

Development and hard development are two of several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). Development represents all development, scaled from 0 to 10 by development intensity. Hard development is a subset of development, with a value of 1 for very high intensity development only. Both layers come from DSLland, the primary landcover map. These are dynamic settings variables, increasing with future urban growth.


Designing Sustainable Landscapes: Substrate Mobility Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan B. Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Substrate Mobility Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan B. Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

Substrate mobility is one of several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). Substrate mobility measures the realized mobility of the physical substrate, due to both substrate composition (e.g., sand) and exposure to forces (wind and water) that transport material. This is an important attribute of certain dynamic systems (e.g., coastal dune systems); given as a simple index of mobility (1 = stable, 10 = highly mobile). Substrate mobility is assigned by landcover class, derived from expert opinion. This settings variable is dynamic ...


Designing Sustainable Landscapes: Terrestrial Barriers Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan B. Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Terrestrial Barriers Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan B. Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

Terrestrial barriers is one of several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). Terrestrial barriers measures the relative degree to which roads and railroads may physically impede movement of terrestrial organisms. It is derived by assigning an expertderived score to each road/railroad class to reflect the increasing physical impediment of larger roads, and adjusting these scores at road-stream crossings (i.e., bridge or culvert) based either on a custom algorithm applied to field measurements of the crossing structure or predictions from a ...


Designing Sustainable Landscapes: Tides Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan B. Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Tides Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan B. Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

Tides is one of several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). Tides estimates the probability that a point is intertidal or subtidal. It is derived from a logistic regression model using tide range and elevation to distinguish mapped salt marshes from uplands.


Designing Sustainable Landscapes: Topographic Wetness And Flow Volume Settings Variables, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Topographic Wetness And Flow Volume Settings Variables, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

Topographic wetness and flow volume are two of several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). These variables are two ways of assessing the flow of water; they share an underlying algorithm. Topographic wetness gives an estimate of the amount of moisture at any point in the landscape based on topography, which has a major effect on species habitat, soils, and the nutrient cycle. It ranges, in arbitrary units, from low values at hilltops and steep upper slopes to high values in low ...


Designing Sustainable Landscapes: Wind Exposure Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Wind Exposure Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

Wind exposure is one of several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). Wind exposure gives the mean sustained wind speed (m/s) at 50 m height. High wind speeds can shape natural communities, especially on exposed high peaks.


Designing Sustainable Landscapes: Water Salinity Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Water Salinity Settings Variable, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

Water salinity is one of several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). Salinity, which varies from 0‰ in freshwater to 30‰ in seawater, is a major driver of aquatic systems, as very few organisms can survive across this full range.


Designing Sustainable Landscapes: Index Of Ecological Integrity, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Index Of Ecological Integrity, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

The index of ecological integrity (IEI) is a measure of relative intactness (i.e., freedom from adverse human modifications and disturbance) and resiliency to environmental change (i.e., capacity to recover from or adapt to changing environmental conditions driven by human land use and climate change). It is a composite index derived from up to 21 different landscape metrics, each measuring a different aspect of intactness (e.g., road traffic intensity, percent impervious) and/or resiliency (e.g., ecological similarity, connectedness) and applied to each 30 m cell (see technical document on integrity, McGarigal et al 2017). The index is ...


Designing Sustainable Landscapes: Habitat Loss, Mowing And Plowing, Microclimate Alterations, Edge Predators, Domestic Predators, Invasive Plants, And Invasive Earthworms Metrics, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand Jan 2018

Designing Sustainable Landscapes: Habitat Loss, Mowing And Plowing, Microclimate Alterations, Edge Predators, Domestic Predators, Invasive Plants, And Invasive Earthworms Metrics, Kevin Mcgarigal, Brad Compton, Ethan Plunkett, Bill Deluca, Joanna Grand

Data and Datasets

This document describes a suite of stressor metrics that assess different aspects of the effects of roads and development on ecological integrity (see technical document on integrity, McGarigal et al 2017). They share a common algorithm, but each has unique parameters. These metrics are obviously highly correlated, but each assesses a different aspect of the effects of roads and development on ecological integrity. These metrics are elements of the ecological integrity analysis of the Designing Sustainable Landscapes (DSL) project (McGarigal et al 2017). Consisting of a composite of 21 stressor and resiliency metrics, the index of ecological integrity (IEI) assesses ...