Digital Commons Network^™

Indirect Excitons And Many-Body Interactions In Ingaas Double Quantum Wells, Christopher L. Smallwood, Rachel Owen, Matthew W. Day, Takeshi Suzuki, Rohan Singh, Travis M. Autry, Smriti Bhalerao, Fauzia Jabeen, Steven T. Cundiff

Faculty Research, Scholarly, and Creative Activity

Spatially indirect excitons in semiconductor quantum wells are relevant to basic research and device applications because they exhibit enhanced tunability, delocalized wave functions, and potentially longer lifetimes relative to direct excitons. Here we investigate the properties of indirect excitons and their coupling interactions with direct excitons in asymmetric InGaAs double quantum wells using optical multidimensional coherent spectroscopy and photoluminescence excitation spectroscopy. Analyses of the spectra confirm a strong influence of many-body effects and reveal that excited-state zero-quantum coherences between direct and indirect excitons in the quantum wells dephase faster than the much-higher-energy single-quantum coherences between excitonic excited states and ground …

Euler’S Formula For General Graph Embeddings, Doug Bauer, Linda Lesniak, Edward Schmeichel

Faculty Research, Scholarly, and Creative Activity

Consider an embedding of a graph G(v,e) with v≥1 vertices and e≥0 edges into a closed surface s, with r resulting regions. If G is connected and every region is a 2-cell (a so-called 2-cell embedding), Euler’s formula is the relation v−e+r=χ(s), where χ(s) denotes the Euler characteristic of s. Here we give a generalization of Euler’s formula which applies to any embedding (2-cell or not) of any graph (connected or not) into any surface (orientable or not), with several interesting corollaries. One rather striking corollary is the converse of Euler’s formula itself: If an embedding of a graph G(v,e) …

Advancing The Upper Class E Traffic Management (Etm) Concept: Results Of Nasa’S First Etm Collaborative Evaluation With Industry Partners, Deborah L. Bakowski, Connie L. Brasil, Kevin Christian Garzon Galindo, Abhinay Tiwari, Paul U. Lee, Conrad Dang-Gabriel, Jeffrey Homola, Mark Evans

Faculty Research, Scholarly, and Creative Activity

Innovative aircraft design and emerging technologies are enabling new types of uncrewed, high-altitude long endurance (HALE) vehicles, including fixed-wing HALE vehicles and stratospheric balloons to operate above 60,000 feet. However, due to a variety of factors including the diverse performance characteristics and extended mission duration of these new vehicles, the Air Traffic Management system faces challenges in meeting the needs of this high-altitude environment. To address these challenges, the Higher Airspace (HA)/Upper Class E Traffic Management (ETM) concept proposes using a scalable, cooperative approach tailored for high-altitude operations. To evaluate the feasibility of the HA/ETM concept, NASA Ames Research Center …

Radial Velocities And Stellar Populations For A Sample Of Matlas Survey Dwarfs, Kate Southon, Jonah S. Gannon, Duncan A. Forbes, Arsen Levitskiy, Maria Luisa Buzzo, Aaron J. Romanowsky, Jean P. Brodie

Faculty Research, Scholarly, and Creative Activity

Spectroscopic observations are essential for confirming associations, measuring kinematics, and determining stellar populations in dwarf galaxies. Here, we present Keck Cosmic Web Imager spectra for 12 MATLAS survey dwarfs. For 9, we confirm recession velocities consistent with their literature-assumed host galaxies. We propose revisions of the host galaxy associations for MATLAS-631, 1494, and 1938. For MATLAS-1494, our measured redshift reclassifies it from an ultra-diffuse galaxy candidate to a dwarf galaxy that is of smaller physical size and places it in the field. It also appears old and passive, providing a challenge to models that invoke quenching by tidal effects. Additionally, …

Navigating Multiple Virtual Teams: How Variety In Communication Rules Affects Knowledge Sharing, Valerio Incerti, Kelly J. Fadel, Elisa Mattarelli, Fabiola Bertolotti, Francesca Bellesia, Paula Ungureanu, Katherine M. Chudoba

Faculty Research, Scholarly, and Creative Activity

In contemporary workplaces, individuals are often members of more than one virtual team at a time, that is, they experience multiple virtual team membership (MVTM), and they are subjected to context variety due to different rules across their teams. The aim of this paper is to understand the relationship between context variety related to communication rules and knowledge sharing in situations of MVTM. We propose that context variety and switching between teams negatively affect the individual capability to acquire and provide knowledge resources in a team, due in part to an increased perception of role overload. Through an experimental study, …

Aerosol-Cloud Interactions In Cirrus Clouds Based On Global-Scale Airborne Observations And Machine Learning Models, Derek Ngo, Minghui Diao, Ryan J. Patnaude, Sarah Woods, Glenn Diskin

Faculty Research, Scholarly, and Creative Activity

Cirrus cloud formation and evolution are subject to the influences of thermodynamic and dynamic conditions and aerosols. This study developed near global-scale in situ aircraft observational datasets based on 12 field campaigns that spanned from the polar regions to the tropics from 2008 to 2016. Cirrus cloud microphysical properties were investigated at temperatures ≤-40 °C, including ice water content (IWC), ice crystal number concentration (Ni), and number-weighted mean diameter (Di). Positive correlations were found between the fluctuations of these ice microphysical properties and the fluctuations of aerosol number concentrations for larger (>500 nm) and smaller (>100 nm) aerosols …

On Two-Generator Subgroups Of Mapping Torus Groups, Naomi Andrew, Edgar Bering Iv, Ilya Kapovich, Stefano Vidussi, Peter Shalen

Faculty Research, Scholarly, and Creative Activity

We prove that if (Formula presented.) is the mapping torus group of an injective endomorphism (Formula presented.) of a free group (Formula presented.) (of possibly infinite rank), then every two-generator subgroup (Formula presented.) of (Formula presented.) is either free or a (finitary) sub-mapping torus. As an application we show that if (Formula presented.) is a fully irreducible atoroidal automorphism, then every two-generator subgroup of (Formula presented.) is either free or has finite index in (Formula presented.).

Conniff, Michael L. (1942-2025), San Jose State University

Emeritus and Retired Faculty Biographies

University of California, 1968, BA, Latin American Studies

Stanford University, 1969, MA, Latin American Studies

Stanford University, 1976, Ph.D., History

Affective Polarization In Latin America, Juan A. Moraes, Sergio Béjar

Faculty Research, Scholarly, and Creative Activity

Studies on the determinants and consequences of affective polarization have proliferated in the past decade, focusing mostly on the US and Western European countries. Empirical and anecdotal evidence presented in this chapter, however, suggests that such a phenomenon is also prevalent in many Latin American countries, which may have important consequences for the stability and survival of democracy in a region where partisan institutions tend to be weak. In this chapter, we present a critical review of the scant literature on affective polarization in Latin America. We then carefully analyze levels of partisan affective polarization (PAP) and leader affective polarization …

Data And Ai Mystification: Ownership, Control, And Financialization In The Platform, Andrew W. Alexander

Faculty Research, Scholarly, and Creative Activity

The social relation between the platform and its users is defined by engagement with digital infrastructures and the rendition of this engagement into data. User-data, however, are surrounded by regulatory and legal ambiguities as they are not accounted for as intangible assets and their ownership and control are not transparent. I investigate how platforms rectify these ambiguities to realize user-data value as codified capital through an intensive case study of two major platforms. I use qualitative content analysis (QCA) to analyze annual and earnings reports, terms of service (ToS) agreements, and internal documents from 2017 through 2023 with qualitative data …

Explainable Use Of Foundation Models For Job Hiring, Vishnu S. Pendyala, Neha Bais Thakur, Radhika Agarwal

Faculty Research, Scholarly, and Creative Activity

Automating candidate shortlisting is a non-trivial task that stands to benefit substantially from advances in artificial intelligence. We evaluate a suite of foundation models such as Llama 2, Llama 3, Mixtral, Gemma-2b, Gemma-7b, Phi-3 Small, Phi-3 Mini, Zephyr, and Mistral-7b for their ability to predict hiring outcomes in both zero-shot and few-shot settings. Using only features extracted from applicants’ submissions, these models, on average, achieved an AUC above 0.5 in zero-shot settings. Providing a few examples similar to the job applicants based on a nearest neighbor search improved the prediction rate marginally, indicating that the models perform competently even without …

An Ambient Nox Reduction Reactor System With And Without Forced Air, Hamid Rahai, Rylan Moffit, Komal Gada, Jeremy Bonifacio

Mineta Transportation Institute

Ambient nitrogen oxide (NOX) is one of the main ingredients involved in the formation of ground-level ozone (smog), which contributes to global warming and the formation of particulates in the atmosphere and causes respiratory illnesses, especially in children, older adults, and people with lung diseases. Investigations on adding titanium dioxide (TiO2) nanoparticles to the paint used on concrete surfaces such as buildings and its potential in reducing ambient NOX concentration have provided opportunities for the research and development of methods for passive control and filtration of the ambient NOX. The present research used numerical geometrical optimization to identify an optimized …

Sjsu Erfa News, Summer 2025, San Jose State University, Emeritus And Retired Faculty Association

Emeritus and Retired Faculty Association (ERFA) Newsletter

Volume 38, No 4

A Simple Model Of Spiral Galaxies From Geometric Optics, Bogdan Szafraniec, James N. Blake

Faculty Research, Scholarly, and Creative Activity

We propose a simple model of spiral galaxies based on the interference of gravitational waves. The interference is deduced from geometric optics analysis of the refractive index profiles that mimic the behavior of gravitational potentials −1/r and r². We analyze the refractive index profiles, n(r)² = a + b/r and n(r)² = a + br², because they are realistically shaped and yield closed form solutions. The two profiles yield similar physical results, showing that the physical interpretation is not dependent on the exact details of the profile. The first profile yields trajectories that can …

Soil Temperature, Environment, And Moisture Monitoring Network—A Low-Cost Sensing Network For Alabama, Nick Perlaky, W. Lee Ellenburg, Udaysankar Nair, Nick Klein, Michael B. Solomon

Faculty Research, Scholarly, and Creative Activity

In order to bolster drought assessment and forecasting capabilities in Alabama, The University of Alabama in Huntsville has developed a network of rapidly deployable, low-cost soil moisture, temperature, and environment monitoring stations (STEMMNet). This network provides near-real-time transmission of in-situ sensed, high temporal resolution soil data, offering an extension beyond climatological analysis into operational use. Stations are manufactured using commercially available, inexpensive hardware and use low-cost sensors which demonstrated comparable accuracy when evaluated against an existing research-grade soil moisture network. Months of testing in a variety of environments allowed for several system optimizations, yielding a robust network with a high …

Effect Of Tai Chi Practice On The Adaptation To Sensory And Motor Perturbations While Standing In Older Adults, Arion Dey, Huiyeong Chang, Laila Shaaban, Armaan Suga, Genavieve Braden, Andres Bustamante, Jisang Park, Shenhua Zhang, Yang Hu, Manuel E. Hernandez

Faculty Research, Scholarly, and Creative Activity

Tai Chi provides an age-appropriate exercise to decrease fall risks in older adults. However, the exact mechanism underlying the benefits of Tai Chi practice remains an open question. Thus, this study examined how aging and Tai Chi practice impact adaptation to sensory and motor perturbations while standing. We hypothesized that older Tai Chi practitioners would exhibit a decreased reliance on visual processes as sensory and motor perturbations increased, relative to naive healthy older adults. Using rambling and trembling decompositions of the center of pressure (COP) and frequency-domain features, we examined changes in low (0–0.3 Hz), medium (0.3–1 Hz), and high …

Quantifying Marine Carbon Dioxide Removal Via Alkalinity Enhancement Across Circulation Regimes Using Ecco-Darwin And 1d Models, Kay Suselj, Dustin Carroll, Daniel Whitt, Bridget Samuels, Dimitris Menemenlis, Hong Zhang, Nate Beatty, Anna Savage

Faculty Research, Scholarly, and Creative Activity

Ocean Alkalinity Enhancement (OAE) is emerging as a viable method for removing anthropogenic (Formula presented.) emissions from the atmosphere to mitigate climate change. To achieve substantial carbon reductions, OAE would need to be deployed at scale across the global ocean. Hence, there is a need to quantify how the efficiency of OAE varies globally across a range of space-time scales in preparation for field deployments. Here we develop a marine carbon dioxide removal (mCDR) efficiency evaluation framework based on the data-assimilative ECCO-Darwin ocean biogeochemistry model, which separates and quantifies two key factors over seasonal to multi-annual timescales: (a) mCDR potential, …

Co-Designed Resources To Improve Sleep Health In Young Shiftworkers: A Qualitative Study, Alexandra E. Shriane, Grace E. Vincent, Sally A. Ferguson, Charlotte C. Gupta, Tracy Kolbe-Alexander, Madeline Sprajcer, Cassie J. Hilditch, Robert Stanton, Matthew J.W. Thomas, Jessica L. Paterson, Jamie Marino, Gabrielle Rigney

Faculty Research, Scholarly, and Creative Activity

Introduction: Shiftwork contributes to poor sleep and circadian disruption, leading to adverse health outcomes. With a high number of young adults (18–25 years) engaging in shiftwork, exposure to these health challenges can occur from early adulthood. Therefore, there is an urgent need for age- and career-stage-appropriate resources focused on sleep health to mitigate poor health outcomes as early as possible. Given the absence of such resources, this study aimed to develop tailored, evidence-based sleep health materials for young shiftworkers. Methods: A participatory approach was employed, with co-designers (n = 48) attending 1–2 online workshops to develop sleep health resources for …

Paving The Way For Improved Representation Of Coupled Physical And Biogeochemical Processes In Arctic River Plumes—A Case Study Of The Mackenzie Shelf, Clément Bertin, Dustin Carroll, Dimitris Menemenlis, Stephanie Dutkiewicz, Hong Zhang, Melissa Schwab, Raphaël Savelli, Atsushi Matsuoka, Manfredi Manizza, Charles E Miller, Simon Bowring, Bertrand Guenet, Vincent Le Fouest

Faculty Research, Scholarly, and Creative Activity

Processes affecting the transformation of riverine dissolved organic carbon (DOC) across the land-to-ocean aquatic continuum are still poorly constrained in Arctic models, leading to large uncertainties in simulated air–sea CO2 fluxes of the coastal periphery. Here we use the ECCO-Darwin regional configuration of the Southeastern Beaufort Sea to analyze the sensitivity of simulated carbon cycling to (1) the model vertical discretization and (2) different parameterizations of Mackenzie River carbon discharge. We show that riverine DOC lifetime rather than its volume largely modulates Mackenzie River plume air–sea CO2 fluxes, leading to the Southeastern Beaufort Sea (SBS) being either a source (0.03 …

Hydrogen Fuel Cell Application For Port Drayage Truck: Integrated Transportation And Energy Modeling, Shams Tanvir, Emu Ghosh

Mineta Transportation Institute

This report investigates the viability of hydrogen Fuel Cell Electric Vehicles (FCEVs) for port drayage applications, focusing on both energy modeling and economic feasibility. Port drayage—trucking operations that move goods a short distance to and from ports—is a key part of freight logistics and the critical movement of goods in American communities. This project developed a microscopic energy consumption model using second-by-second activity data from 38 Class 8 diesel drayage trucks operating in Southern California. The model emulated FCEV operations and determined an average hydrogen fuel consumption of 0.15 kg/mile across 749 trips. This data informed a levelized cost of …

Santa, Socials, And Secrets: Hard Cases For Epistemic Rights, Étienne Brown, Rebecca Chan

Faculty Research, Scholarly, and Creative Activity

In The Right to Know, Lani Watson forcefully argues in favor of recognizing epistemic rights to all humans. In this paper, we apply Watson’s framework to three hard cases. First, we consider interpersonal relationships and suggest that there is room to explore how epistemic rights bear on, e.g., whether parents can permissibly lie to or mislead their children by asserting the existence of Santa Claus. Second, we turn to social media platforms and contend that Watson’s framework is compatible with contrasting moderation policies and transparency requirements. Third, we examine a foundational case of legal ethics—the buried bodies case—which raises the …

The Impact Of Artificial Intelligence On Ecojustice And Ethics, Vishnu S. Pendyala

Faculty Research, Scholarly, and Creative Activity

Artificial Intelligence (AI) has attained human-level performance in tasks like text summarization, machine translation, and code generation while handling multimodal data. Despite these advances, AI poses challenges such as generating false or biased outputs, causing discrimination, and exhibiting opaque decision-making processes that hinder bias mitigation. Additionally, training large language models (LLMs) for AI consumes substantial energy and can enable autonomous warfare, posing a threat to eco-justice, and raising sustainability concerns. Their ability to create realistic content poses the risk of misuse and perpetuating misinformation. This article addresses these ethical issues and presents solutions through regulation and technology, with examples of …

Telling The Library’S Story: A Step-By-Step Tutorial For Using Data Visualization To Show Impact On Teaching And Learning, David Vickers Loertscher, Michelle Young

Learning Hub

This tutorial introduces school librarians to the use of data visualization tools for documenting and communicating their impact on teaching and learning. By leveraging accessible platforms like Google Forms and Google Sheets, the authors demonstrate how librarians can build dashboards and real-time visual reports to showcase co-teaching, instructional collaboration, and student engagement. The tutorial features real-world examples, highlights common data sources already available to librarians, and argues that dynamic visual storytelling is a powerful alternative to traditional library statistics.

Orientation-Independent Bubble Trap With Internal Partition For Robust Operation Of Microfluidic Systems, Bhavagyna Vegunta, Charmaine Lui, Max Kim, Joshua Tran, Maya Papez, Anand K. Ramasubramanian, Sang Joon John Lee

Faculty Research, Scholarly, and Creative Activity

A new monolithic bubble trap has been developed with a unique, orientation-independent design. The bubble trap has a spherical cavity and a central partition with internal passages that eliminate air bubbles effectively for extended periods of time. Flow testing was performed in a closed-loop microfluidic system to demonstrate effectiveness and robustness of the bubble trap. Flow rate was continually monitored on a stationary benchtop and also in simulated microgravity conditions on a 3-D random positioning machine. Data collected from flow sensors placed fore and aft of the bubble trap confirmed that randomly occurring bubbles were effectively eliminated by the trap …

Potential Of Co2 Sequestration Through Accelerated Weathering Of Limestone On Ships, Sijia Dong, William M. Berelson, Pierre Forin, Melissa Gutierrez, Dustin Carroll, Dimitris Menemenlis, Albert Y. Kyi, Jess F. Adkins

Faculty Research, Scholarly, and Creative Activity

Calcium carbonate dissolution is the dominant negative feedback in the ocean for neutralizing the acidity from rising atmospheric carbon dioxide. Mimicking this natural process, the accelerated weathering of limestone (AWL) can store carbon as bicarbonate in the ocean for tens of thousands of years. Here, we evaluate the potential of AWL on ships as a carbon sequestration approach. We show a successful prediction of laboratory measurements using a model that includes the most recent calcite dissolution kinetics in seawater. When simulated along a Pacific shipping lane in the Estimating the Circulation and Climate of the Ocean–Darwin ocean–general circulation model, surface …

Candidate Dark Galaxy-2: Validation And Analysis Of An Almost Dark Galaxy In The Perseus Cluster, Dayi Li, Qing Liu, Gwendolyn M. Eadie, Roberto G. Abraham, Francine R. Marleau, William E. Harris, Pieter Van Dokkum, Aaron J. Romanowsky, Shany Danieli, Patrick E. Brown, Alex Stringer

Faculty Research, Scholarly, and Creative Activity

Candidate Dark Galaxy-2 (CDG-2) is a potential dark galaxy consisting of four globular clusters (GCs) in the Perseus cluster, first identified in D. Li et al. through a sophisticated statistical method. The method searched for overdensities of GCs from a Hubble Space Telescope (HST) survey targeting Perseus. Using the same HST images and new imaging data from the Euclid survey, we report the detection of extremely faint but significant diffuse emission around the four GCs of CDG-2. We thus have exceptionally strong evidence that CDG-2 is a galaxy. This is the first galaxy detected purely through its GC population. Under …

Finite-Temperature Kinetic Ferromagnetism In The Square-Lattice Hubbard Model, Robin C. Newby, Ehsan Khatami

Faculty Research, Scholarly, and Creative Activity

While the exact phase diagram of the Fermi-Hubbard model remains poorly understood despite decades of progress, nearly 60 years ago Nagaoka proved that a single dopant in an otherwise half-filled Hubbard system can bring about ferromagnetism through kinetic means. The phenomenon was recently observed with ultracold atoms in triangular optical lattices. Here, we explore the kinetic ferromagnetism within the square lattice Hubbard model and its strong-coupling counterpart, the t-J model, at finite temperatures in the thermodynamic limit via numerical linked-cluster expansions. We find evidence of ferromagnetic Nagaoka polarons at dopings up to ∼30% away from half filling for a variety …

Contributions Of California Teacher Librarians To Student Achievement, Keith Curry Lance, Caitlin Gerrity

Learning Hub

This article assesses the contributions of California Teacher Librarians (TLs) to student achievement, specifically in the area of English Language Arts and Literacy. This comparison-of-means analysis employed two major datasets: the California Department of Education (CDE) school library evaluation survey and California Assessment of Student Performance and Progress (CAASPP) data, both for the 2022-23 school year. This study found that students who met or exceeded ELA standards were more likely to be in schools with: a full-time, certified TL rather than a part-time TL or no TL; a TL–full- or part-time–rather than no TL; a TL staffing a single library …

Surface-Bound Fxiii Enhances Deposition And Straightness Of Fibrin Fibers, Myra Awan, Maya Papez, Ankita P. Walvekar, Sang Joon J. Lee, Kinjal Dasbiswas, Anand K. Ramasubramanian

Faculty Research, Scholarly, and Creative Activity

Cross-linked fibrous networks are central to maintaining the structural integrity and functional relevance of many biological and engineered materials. Fibrin networks are the building blocks of blood clots, mediators of tissue injury and repair, and synthetic wound sealants. Cross-linking of fibrin fibers is catalyzed by the activated form of transglutaminase enzyme FXIIIa, which becomes available in plasma but is also readily presented on the surface of activated platelets and macrophages. The contribution of surface-bound FXIIIa to fibrin structure has not been well understood. In this work, we investigated the role of surface-bound FXIIIa on the formation and structure of fibrin …

Large Language Models For Quantitative Analysis Of Statutory Stringency And Its Correlation With Sexual Assault Crime Rates, Samhita Konduri, Vishnu S. Pendyala

Faculty Research, Scholarly, and Creative Activity

Sexual assault (SA) crimes are among the most important issues for our current society to solve, with these crimes in particular having long-term consequences on victims and their communities. To solve this issue, one approach is to make laws and penalties for these crimes stricter. However, there have not been any studies on the relationship between stricter penalties and lower crime rates, especially about SA crimes, in a quantitative manner. The biggest barrier to conducting a quantitative study on the strictness of laws and statutes is the lack of a standardized measure of how strict a legal text is. This …