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Full-Text Articles in Physical Sciences and Mathematics

Multiple Methods Of Public Engagement: Disaggregating Socio-Spatial Data For Environmental Planning In Western Washington, Usa, Rebecca J. Mclain, David Banis, Alexa Todd, Lee Cerveny Dec 2017

Multiple Methods Of Public Engagement: Disaggregating Socio-Spatial Data For Environmental Planning In Western Washington, Usa, Rebecca J. Mclain, David Banis, Alexa Todd, Lee Cerveny

Geography Faculty Publications and Presentations

Highlights

• The effectiveness of participatory GIS approaches at engaging different publics was explored.

• Online surveys engaged urbanites; community workshops engaged rural residents.

• Urban and rural residents went to similar places but engaged in different activities.

• Use of multiple data collection methods will broaden public engagement.

• Mapping behavior studies are needed to improve understandings of PPGIS data quality.


Two-Photon Excitation, Fluorescence Microscopy, And Quantitative Measurement Of Two-Photon Absorption Cross Sections, Fredrick Michael Dearmond Dec 2017

Two-Photon Excitation, Fluorescence Microscopy, And Quantitative Measurement Of Two-Photon Absorption Cross Sections, Fredrick Michael Dearmond

Dissertations and Theses

As optical microscopy techniques continue to improve, most notably the development of super-resolution optical microscopy which garnered the Nobel Prize in Chemistry in 2014, renewed emphasis has been placed on the development and use of fluorescence microscopy techniques. Of particular note is a renewed interest in multiphoton excitation due to a number of inherent properties of the technique including simplified optical filtering, increased sample penetration, and inherently confocal operation. With this renewed interest in multiphoton fluorescence microscopy, comes an increased demand for robust non-linear fluorescent markers, and characterization of the associated tool set.

These factors have led to an experimental …


Multi-Dimensional Drought Risk Assessment Based On Socio-Economic Vulnerabilities And Hydro-Climatological Factors, Ali Ahmadalipour Nov 2017

Multi-Dimensional Drought Risk Assessment Based On Socio-Economic Vulnerabilities And Hydro-Climatological Factors, Ali Ahmadalipour

Dissertations and Theses

Drought is among the costliest natural hazards developing slowly and affecting large areas, which imposes severe consequences on society and economy. Anthropogenic climate change is expected to exacerbate drought in various regions of the globe, making its associated socioeconomic impacts more severe. Such impacts are of higher concern in Africa, which is mainly characterized by arid climate and lacking infrastructure as well as social development. Furthermore, the continent is expected to experience vast population growth, which will make it more vulnerable to the adverse effects of drought. This study provides the first comprehensive multi-dimensional assessment of drought risk across the …


Analysis Of The Acid-Base Balance Of Mainstream Tobacco Smoke And Its Effect On The Gas/Particle Partitioning Of Nicotine, Amy Kathleen Devita-Mcbride Nov 2017

Analysis Of The Acid-Base Balance Of Mainstream Tobacco Smoke And Its Effect On The Gas/Particle Partitioning Of Nicotine, Amy Kathleen Devita-Mcbride

Dissertations and Theses

Tobacco smoke particulate matter (PM) is a complex mixture of condensed organic compounds, with about 5 to 10% water. Its general properties are similar in some respects to that of atmospheric organic aerosol PM and thus provides a useful surrogate when studying atmospheric PM. Due to its ability to undergo acid-base chemistry, nicotine is of particular interest in the tobacco smoke system. The gas/particle partitioning of nicotine depends on the protonation state of nicotine in the particles, so the distribution of nicotine between these phases provides a means of understanding the acid-base balance in the tobacco smoke system. The goal …


Assessing The Impact Of Land Use And Travel On Carbon Dioxide Emissions In Portland, Oregon, Zakari Mumuni Nov 2017

Assessing The Impact Of Land Use And Travel On Carbon Dioxide Emissions In Portland, Oregon, Zakari Mumuni

Dissertations and Theses

The negative consequences of sprawling metropolitan regions have attracted attention in both academia and in practice regarding how to better design settlements and alter travel behavior in a quest to curtail vehicle emissions. Studies that have attempted to understand the nexus between land use, travel and vehicle emissions have not been able to address the issue of self-selection in a satisfactory manner. Self-selection occurs when households choose their residential location based, in part, on expected travel behavior. This non-random experience makes the use of traditional regression frameworks that strongly rely on random sampling, unsuitable. This replication study's purpose was to …


Entropy Production And Volume Contraction In Thermostated Hamiltonian Dynamics, John D. Ramshaw Nov 2017

Entropy Production And Volume Contraction In Thermostated Hamiltonian Dynamics, John D. Ramshaw

Physics Faculty Publications and Presentations

Patra et al. [Int. J. Bifurcat. Chaos 26, 1650089 (2016)] recently showed that the time-averaged rates of entropy production and phase-space volume contraction are equal for several different molecular dynamics methods used to simulate nonequilibrium steady states in Hamiltonian systems with thermostated temperature gradients. This equality is a plausible statistical analog of the second law of thermodynamics. Here we show that those two rates are identically equal in a wide class of methods in which the thermostat variables z are determined by ordinary differential equations of motion (i.e., methods of the Nosé-Hoover or integral feedback control type). This …


Mixing Times Of Organic Molecules Within Secondary Organic Aerosol Particles: A Global Planetary Boundary Layer Perspective, Adrian M. Maclean, Christopher L. Butenhoff, James W. Grayson, Kelley Barsanti, Jose L. Jimenez, Allan K. Bertram Nov 2017

Mixing Times Of Organic Molecules Within Secondary Organic Aerosol Particles: A Global Planetary Boundary Layer Perspective, Adrian M. Maclean, Christopher L. Butenhoff, James W. Grayson, Kelley Barsanti, Jose L. Jimenez, Allan K. Bertram

Physics Faculty Publications and Presentations

When simulating the formation and life cycle of secondary organic aerosol (SOA) with chemical transport models, it is often assumed that organic molecules are well mixed within SOA particles on the timescale of 1 h. While this assumption has been debated vigorously in the literature, the issue remains unresolved in part due to a lack of information on the mixing times within SOA particles as a function of both temperature and relative humidity. Using laboratory data, meteorological fields, and a chemical transport model, we estimated how often mixing times are < 1 h within SOA in the planetary boundary layer (PBL), the region of the atmosphere where SOA concentrations are on average the highest. First, a parameterization for viscosity as a function of temperature and RH was developed for α-pinene SOA using room-temperature and low-temperature viscosity data for α-pinene SOA generated in the laboratory using mass concentrations of ∼ 1000 µg m−3. Based on this parameterization, the mixing times within α-pinene SOA are < 1 h for 98.5 % and 99.9 % of the occurrences in the PBL during January and July, respectively, when concentrations are significant (total organic aerosol concentrations are > 0.5 µg m−3 at the surface). Next, as a starting …


Deconstruction In Portland: Summary Of Activity, Emma Willingham, Peter Hulseman, Mike Paruszkiewicz Nov 2017

Deconstruction In Portland: Summary Of Activity, Emma Willingham, Peter Hulseman, Mike Paruszkiewicz

Northwest Economic Research Center Publications and Reports

On October 31st, 2016, the City of Portland instituted an ordinance requiring the deconstruction of all residential homes and duplexes built prior to 1917 or possessing a historical designation. Deconstruction is a relatively new industry, and with this local regulatory encouragement, several new contractors became certified to participate in the expanded market. This report provides background on the industry, largely from the 2016 report researched and written by the Northwest Economic Research Center (NERC) in anticipation of the requirement, and an examination of what has occurred in the year following the ordinance’s passage, using deconstruction and demolition permit data and …


Northwest Forest Plan The First 20 Years (1994-2013): Watershed Condition Status And Trend, Stephanie A. Miller, Sean N. Gordon, Peter Eldred, Ronald M. Beloin, Steve Wilcox, Mark Raggon, Heidi Andersen, Ariel Muldoon Nov 2017

Northwest Forest Plan The First 20 Years (1994-2013): Watershed Condition Status And Trend, Stephanie A. Miller, Sean N. Gordon, Peter Eldred, Ronald M. Beloin, Steve Wilcox, Mark Raggon, Heidi Andersen, Ariel Muldoon

Institute for Sustainable Solutions Publications and Presentations

We used two data sets to evaluate stream and upslope/riparian condition for sixth-field watersheds in each aquatic province within the Northwest Forest Plan (NWFP) area. The stream evaluation was based on stream sampling data collected from 2002 to the 2013 (214 watersheds) as part of an eight year repeating (rotating) sample design. We are currently halfway through our second rotation of stream sampling, and have repeated 110 watersheds since the second rotation began in 2009. The analysis presented in this report uses roughly half the number of watersheds as was originally intended by the sample design since re-visitation will not …


Building Planner Commitment: Are California’S Sb 375 And Oregon’S Sb 1059 Models For Climate-Change Mitigation?, Keith Bartholomew, David Proffitt Nov 2017

Building Planner Commitment: Are California’S Sb 375 And Oregon’S Sb 1059 Models For Climate-Change Mitigation?, Keith Bartholomew, David Proffitt

TREC Final Reports

California’s Sustainable Communities and Climate Protection Act (SB 375) and the Oregon Sustainable Transportation Initiative (SB 1059) have made them the first states in the nation to try and reduce greenhouse gas (GHG) emissions using the transportation-planning process. Evaluating how these pioneering laws have changed local planning processes – as well as plans themselves – in each state provides insight into the laws’ effectiveness at changing development patterns in a way that reduces GHG emissions, without waiting decades to see the effects in the built environment. Both states’ laws require metropolitan planning organizations (MPOs) and the municipalities that comprise them …


Using The Planning Process To Mitigate Climate Change, Keith Bartholomew Nov 2017

Using The Planning Process To Mitigate Climate Change, Keith Bartholomew

TREC Project Briefs

This research evaluates how Oregon’s SB 1059 and California’s SB 375 have integrated climate change mitigation strategies into local planning processes, and seeks to understand how transportation planning can help slow climate change.


Ion Transport Across Biological Membranes By Carborane-Capped Gold Nanoparticles, Marcin P. Grzelczak, Stephen P. Danks, Robert C. Klipp, Domagoj Belic, Adnana Zaulet, Casper Kunstmann-Olsen, Dan F. Bradley, Tatsuya Tsukuda, Clara ViñAs, Francesc Teixidor, Jonathan J. Abramson, Mathias Brust Nov 2017

Ion Transport Across Biological Membranes By Carborane-Capped Gold Nanoparticles, Marcin P. Grzelczak, Stephen P. Danks, Robert C. Klipp, Domagoj Belic, Adnana Zaulet, Casper Kunstmann-Olsen, Dan F. Bradley, Tatsuya Tsukuda, Clara ViñAs, Francesc Teixidor, Jonathan J. Abramson, Mathias Brust

Physics Faculty Publications and Presentations

Carborane-capped gold nanoparticles (Au/carborane NPs, 2–3 nm) can act as artificial ion transporters across biological membranes. The particles themselves are large hydrophobic anions that have the ability to disperse in aqueous media and to partition over both sides of a phospholipid bilayer membrane. Their presence therefore causes a membrane potential that is determined by the relative concentrations of particles on each side of the membrane according to the Nernst equation. The particles tend to adsorb to both sides of the membrane and can flip across if changes in membrane potential require their repartitioning. Such changes can be made either with …


Accessing Blue Spaces: Social And Geographic Factors Structuring Familiarity With, Use Of, And Appreciation Of Urban Waterways, Melissa Haeffner, Douglas Jackson-Smith, Martin Buchert, Jordan Risley Nov 2017

Accessing Blue Spaces: Social And Geographic Factors Structuring Familiarity With, Use Of, And Appreciation Of Urban Waterways, Melissa Haeffner, Douglas Jackson-Smith, Martin Buchert, Jordan Risley

Environmental Science and Management Faculty Publications and Presentations

Are urban waterways amenities, and if so, are there inequities in household access? While urban waterways represent a potential site for access to nature within the urban environment, there have been few studies on the accessibility and interactions with water features in particular, what we refer to as “blue spaces." This study drew on a sample of households in Northern Utah living in neighborhoods with a nearby river or canal to ask if local waterways provide positive impacts to households and if proximity to them increased the likelihood of households spending time at them and being familiar with them. We …


On The Temporal Effects Of Mobile Blockers In Urban Millimeter-Wave Cellular Scenarios, Margarita Gapeyenko, Mikhail Gerasimenko, Andrey Samuylov, Dmitri Moltchanov, Sarabjot Singh, Mustafa Riza Akdeniz, Ehsan Aryafar, Nageen Himayat, Sergey Andreev, Yevgeni Koucheryavy Nov 2017

On The Temporal Effects Of Mobile Blockers In Urban Millimeter-Wave Cellular Scenarios, Margarita Gapeyenko, Mikhail Gerasimenko, Andrey Samuylov, Dmitri Moltchanov, Sarabjot Singh, Mustafa Riza Akdeniz, Ehsan Aryafar, Nageen Himayat, Sergey Andreev, Yevgeni Koucheryavy

Computer Science Faculty Publications and Presentations

Millimeter-wave (mmWave) propagation is known to be severely affected by the blockage of the line-of-sight (LoS) path. In contrast to microwave systems, at shorter mmWave wavelengths such blockage can be caused by human bodies, where their mobility within environment makes wireless channel alternate between the blocked and non-blocked LoS states. Following the recent 3GPP requirements on modeling the dynamic blockage as well as the temporal consistency of the channel at mmWave frequencies, in this paper a new model for predicting the state of a user in the presence of mobile blockers for representative 3GPP scenarios is developed: urban micro cell …


An Analysis Of The Optimal Mix Of Global Energy Resources And The Potential Need For Geoengineering Using The Ceagom Model, John George Anasis, M. A. K. Khalil, George G. Lendaris, Christopher L. Butenhoff, Randall Bluffstone Oct 2017

An Analysis Of The Optimal Mix Of Global Energy Resources And The Potential Need For Geoengineering Using The Ceagom Model, John George Anasis, M. A. K. Khalil, George G. Lendaris, Christopher L. Butenhoff, Randall Bluffstone

Systems Science Faculty Publications and Presentations

Humanity faces tremendous challenges as a result of anthropogenic climate change caused by greenhouse gas emissions. The mix of resources deployed in order to meet the energy needs of a growing global population is key to addressing the climate change issue. The goal of this research is to examine the optimal mix of energy resources that should be deployed to meet a forecast global energy demand while still meeting desired climate targets. The research includes the unique feature of examining the role that geoengineering can play in this optimization. The results show that some form of geoengineering is likely to …


Investigating Statistics Teachers' Knowledge Of Probability In The Context Of Hypothesis Testing, Jason Mark Asis Dolor Oct 2017

Investigating Statistics Teachers' Knowledge Of Probability In The Context Of Hypothesis Testing, Jason Mark Asis Dolor

Dissertations and Theses

In the last three decades, there has been a significant growth in the number of undergraduate students taking introductory statistics. As a result, there is a need by universities and community colleges to find well-qualified instructors and graduate teaching assistants to teach the growing number of statistics courses. Unfortunately, research has shown that even teachers of introductory statistics struggle with concepts they are employed to teach. The data presented in this research sheds light on the statistical knowledge of graduate teaching assistants (GTAs) and community college instructors (CCIs) in the realm of probability by analyzing their work on surveys and …


Data Envelopment Analysis Using Glpkapi In R, Konrad Miziolek, Jordan Beary, Shreyas Vasanth, Surekha Chanamolu, Rudraxi Mitra Oct 2017

Data Envelopment Analysis Using Glpkapi In R, Konrad Miziolek, Jordan Beary, Shreyas Vasanth, Surekha Chanamolu, Rudraxi Mitra

Engineering and Technology Management Student Projects

The work done here is primarily a wrapper function written to separate some of the more difficult-to-use glpkAPI functionality from the end-user. The user, when prompted, selects the appropriate configuration of the .mod file to the task (for example, output-oriented CRS), and the data file, as a .dat. The function then loads the required glpkAPI library, and carries forward the model. It allocates the problem and workspace, reads the model file and data file the user selects, builds the problem, and solves it. The function returns primal values, and, if dual = TRUE is selected, also returns dual weights.


Elution Tailing Of Nonaqueous Phase Liquids In Porous Media, Louisa Orr Oct 2017

Elution Tailing Of Nonaqueous Phase Liquids In Porous Media, Louisa Orr

Civil and Environmental Engineering Undergraduate Honors Theses

A variety of porous media were studied to characterize contaminant dispersion over time. This work looked at a compilation of previously published studies to investigate the dependence of long term elution tailing trends on particular soil characteristics. Recession curve analysis was conducted on existing dispersed contaminant literature, to yield the low-concentration recession constant (K). The R2 values correlating the soil properties to contaminant concentration ranged from 0.12494 to 0.95429. The low-concentration recession constant (K) values ranged from 0.9745407 0.9999988. The relationship between K and the soil properties porosity, organic carbon, and fines fraction is increasing. Bulk density and the …


Forest Collaborative Meeting Agenda, Addis Ababa, Ethiopia, Environment For Development (Efd) Initiative Oct 2017

Forest Collaborative Meeting Agenda, Addis Ababa, Ethiopia, Environment For Development (Efd) Initiative

Forest Collaborative Research

Agenda for the Environment for Development (EfD) Initiative Annual Meeting on 27-30 October 2017 at Capital Hotel, Addis Ababa, Ethiopia.


A Comparative Assessment Of Projected Meteorological And Hydrological Droughts: Elucidating The Role Of Temperature, Ali Ahmadalipour, Hamid Moradkhani, Mehmet C. Demirel Oct 2017

A Comparative Assessment Of Projected Meteorological And Hydrological Droughts: Elucidating The Role Of Temperature, Ali Ahmadalipour, Hamid Moradkhani, Mehmet C. Demirel

Civil and Environmental Engineering Faculty Publications and Presentations

The changing climate and the associated future increases in temperature are expected to have impacts on drought characteristics and hydrologic cycle. This paper investigates the projected changes in spatiotemporal characteristics of droughts and their future attributes over the Willamette River Basin (WRB) in the Pacific Northwest U.S. The analysis is performed using two subsets of downscaled CMIP5 global climate models (GCMs) each consisting of 10 models from two future scenarios (RCP4.5 and RCP8.5) for 30 years of historical period (1970–1999) and 90 years of future projections (2010–2099). Hydrologic modeling is conducted using the Precipitation Runoff Modeling System (PRMS) as a …


Random Walks On Digraphs, J.J.P. Veerman Oct 2017

Random Walks On Digraphs, J.J.P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

Let V = {1, · · · n} be a vertex set and S a non-negative row-stochastic matrix (i.e. rows sum to 1). V and S define a digraph G = G(V, S) and a directed graph Laplacian L as follows. If (S)ij > 0 (in what follows we will leave out the parentheses) there is a directed edge j → i. Thus the ith row of S identifies the edges coming into vertex i and their weights. This set of vertices are collectively the neighbors of i, and is denoted by Ni . The diagonal elements Sii are chosen such …


Johnson Creek Bacteria Tmdl Implementation: Status And Trend Analysis Study, John Gala Oct 2017

Johnson Creek Bacteria Tmdl Implementation: Status And Trend Analysis Study, John Gala

Environmental Science and Management Professional Master's Project Reports

Like many other waterbodies in the United States, Johnson Creek, a tributary of the Lower Willamette River is water quality limited for bacteria. Escherichia coli (E. coli), a member of the fecal coliform bacteria group, has been found to have a high association with human pathogens and the occurrences of gastrointestinal illnesses in waters used for contact recreation; E. coli is commonly used as an indicator of fecal contamination. In the State of Oregon water contact recreational standards for fecal exposure is assessed by measuring in stream levels of E. coli. Because Johnson Creek is water quality …


Formalizing The Panarchy Adaptive Cycle With The Cusp Catastrophe, Martin Zwick, Joshua Hughes Oct 2017

Formalizing The Panarchy Adaptive Cycle With The Cusp Catastrophe, Martin Zwick, Joshua Hughes

Systems Science Faculty Publications and Presentations

The panarchy adaptive cycle, a general model for change in natural and human systems, can be formalized by the cusp catastrophe of René Thom's topological theory. Both the adaptive cycle and the cusp catastrophe have been used to model ecological, economic, and social systems in which slow and small continuous changes in two control variables produce fast and large discontinuous changes in system behavior. The panarchy adaptive cycle, the more recent of the two models, has been used so far only for qualitative descriptions of typical dynamics of such systems. The cusp catastrophe, while also often employed qualitatively, is a …


Hydrological Patterns And The Effects Of Land Use On Tss Concentrations And Yields In The Mccarthy Creek Watershed, Portland, Oregon, David Farmer Oct 2017

Hydrological Patterns And The Effects Of Land Use On Tss Concentrations And Yields In The Mccarthy Creek Watershed, Portland, Oregon, David Farmer

Environmental Science and Management Professional Master's Project Reports

The spread of impervious surface areas and the reduction of tree canopy via urbanization has numerous water quality impacts on Pacific Northwest watersheds. One such impact is elevated levels of Total Suspended Solids (TSS) in run-off during storm events, particularly in steep, forested watersheds undergoing urbanization. This project was developed in collaboration with the West Multnomah Soil and Water Conservation District and focused on the McCarthy Creek Watershed, as a case-study watershed located in Portland, OR. The study aimed to identify elevated TSS concentrations and yields during storm events on both mainstem and tributary sampling locations, establish the relationship between …


Quantifying Resilience Of Multiple Ecosystem Services And Biodiversity In A Temperate Forest Landscape, Elena Cantarello, Adrian C. Newton, Phillip A. Martin, Paul M. Evans, Arjan Gosal, Melissa S. Lucash Oct 2017

Quantifying Resilience Of Multiple Ecosystem Services And Biodiversity In A Temperate Forest Landscape, Elena Cantarello, Adrian C. Newton, Phillip A. Martin, Paul M. Evans, Arjan Gosal, Melissa S. Lucash

Geography Faculty Publications and Presentations

Resilience is increasingly being considered as a new paradigm of forest management among scientists, practitioners, and policymakers. However, metrics of resilience to environmental change are lacking. Faced with novel disturbances, forests may be able to sustain existing ecosystem services and biodiversity by exhibiting resilience, or alternatively these attributes may undergo either a linear or nonlinear decline. Here we provide a novel quantitative approach for assessing forest resilience that focuses on three components of resilience, namely resistance, recovery, and net change, using a spatially explicit model of forest dynamics. Under the pulse set scenarios, we explored the resilience of nine ecosystem …


Values Mapping And Counter-Mapping In Contested Landscapes: An Olympic Peninsula (Usa) Case Study, Rebecca J. Mclain, Lee Cerveny, Kelly Biedenweg, David Banis Oct 2017

Values Mapping And Counter-Mapping In Contested Landscapes: An Olympic Peninsula (Usa) Case Study, Rebecca J. Mclain, Lee Cerveny, Kelly Biedenweg, David Banis

Geography Faculty Publications and Presentations

Indigenous peoples, local communities, and other groups can use counter-mapping to make land claims, identify areas of desired access, or convey cultural values that diverge from the dominant paradigm. While sometimes created independently, counter-maps also can be formulated during public participation mapping events sponsored by natural resource planning agencies. Public participation mapping elicits values, uses, and meanings of landscapes from diverse stakeholders, yet individuals and advocacy groups can use the mapping process as an opportunity to make visible strongly held values and viewpoints. We present three cases from the Olympic Peninsula in Washington State to illustrate how stakeholders intentionally used …


Finding Water Scarcity Amid Abundance Using Human–Natural System Models, William K. Jaeger, Adell Amos, Daniel P. Bigelow, Heejun Chang, David R. Conklin, Roy Haggerty, Christian Langpap, Kathleen Moore, Philip Mote, Anne W. Nolin, Andrew J. Plantinga, Cynthia L. Schwartz, Desiree Tullos, David P. Turner Oct 2017

Finding Water Scarcity Amid Abundance Using Human–Natural System Models, William K. Jaeger, Adell Amos, Daniel P. Bigelow, Heejun Chang, David R. Conklin, Roy Haggerty, Christian Langpap, Kathleen Moore, Philip Mote, Anne W. Nolin, Andrew J. Plantinga, Cynthia L. Schwartz, Desiree Tullos, David P. Turner

Geography Faculty Publications and Presentations

Water scarcity afflicts societies worldwide. Anticipating water shortages is vital because of water’s indispensable role in social-ecological systems. But the challenge is daunting due to heterogeneity, feedbacks, and water’s spatial-temporal sequencing throughout such systems. Regional system models with sufficient detail can help address this challenge. In our study, a detailed coupled human–natural system model of one such region identifies how climate change and socioeconomic growth will alter the availability and use of water in coming decades. Results demonstrate how water scarcity varies greatly across small distances and brief time periods, even in basins where water may be relatively abundant overall. …


Ideas & Graphs, Martin Zwick Oct 2017

Ideas & Graphs, Martin Zwick

Systems Science Faculty Publications and Presentations

A graph can specify the skeletal structure of an idea, onto which meaning can be added by interpreting the structure.

This paper considers graphs (but not hypergraphs) consisting of four nodes, and suggests meanings that can be associated with several different directed and undirected graphs.

Drawing on Bennett's "systematics," specifically on the Tetrad that systematics offers as a model of 'activity,' the analysis here shows that the Tetrad is versatile model of problem-solving, regulation and control, and other processes.


Formalizing The Panarchy Adaptive Cycle With The Cusp Catastrophe [Presentation], Martin Zwick, Joshua Hughes Oct 2017

Formalizing The Panarchy Adaptive Cycle With The Cusp Catastrophe [Presentation], Martin Zwick, Joshua Hughes

Systems Science Faculty Publications and Presentations

The panarchy adaptive cycle, a general model for change in natural and human systems, can be formalized by the cusp catastrophe of René Thom's topological theory. Both the adaptive cycle and the cusp catastrophe have been used to model ecological, economic, and social systems in which slow and small continuous changes in two control variables produce fast and large discontinuous changes in system behavior. The panarchy adaptive cycle, the more recent of the two models, has been used so far only for qualitative descriptions of typical dynamics of such systems. The cusp catastrophe, while also often employed qualitatively, is a …


Torrefaction Kinetics Of Hemp Hurds, An Emerging Agricultural Byproduct, In A Small Retort, Tel Jensen Sep 2017

Torrefaction Kinetics Of Hemp Hurds, An Emerging Agricultural Byproduct, In A Small Retort, Tel Jensen

Civil and Environmental Engineering Undergraduate Honors Theses

As knowledge concerning the consequences of unsustainable energy sources and agricultural practices grows, development of low-impact alternatives to both becomes more important. Sustainable sources of biomass offer solutions to both problems. This study characterized the reaction kinetics of torrefying an agricultural byproduct, the woody interior of hemp stems, or hurds. Torrefaction was carried out at 250 °C in small and simple retorts made of galvanized steel pipe. A first-order model most closely approximated the reaction. A sensitivity analysis was performed and the data was adjusted to correct for three potential sources of error, and regressed to find the best fit …