Neutron Displacement Damage in Germanium Tin Photodiodes

GeSn is a promising material for photodiodes in the near-to-mid infrared (IR) spectrum because of new growth methods that enable integration with complementary metal oxide semiconductor (CMOS) technology. While natural germanium has a threshold wavelength of 1800 nm, 6.9 Sn content extends the threshold wavelength to 2700 nm based on a Sn content dependent bandgap. Also, unlike other semiconductors that require liquid nitrogen cooling to act as an IR sensor, GeSn can be operated at room temperature, enabling a wide variety of applications. In this study, photodiodes ranging from 0 to 6.9 tin content were subjected to 1 MeV (Si) equivalent neutron radiation ranging from 4 1012 cm2 to 4 1014 cm2. IV curves, CV curves, and relative photoresponse were measured before and after irradiation to observe change due to displacement damage. While the change in IV measurements varied widely, the photoresponse more than doubled for all irradiated samples, contrary to expectation. The samples of low tin content had a greater increase (as much as 1100 ) than high tin content samples (ranging from 100 to 400 ). Deep-level transient Fourier spectroscopy (DLTFS) was also used to measuredefect levels. The 0 and 6.8 tin samples showed defects at energies of 0.26 eV below the conduction band and 0.17 eV above the valence band, respectively. The 0.26 eV trap is attributed to an A center vacancy-oxygen (V-O) complex and the 0.17 eV trap is attributed to a vacancy-phosphorous (V-P) defect

Eaton Automated Tuft Cutter

The primary purpose of this project was to maximize the efficiency in Eaton\u27s tuft cutting process, which is an essential part of their manufacturing business. The current process is a poor use of both human and physical capital that creates an unnecessary financial burden on the sponsor company, Eaton Corporation. The primary source of this lost money is from paying highly skilled operators to perform tedious tasks beneath their skill-set. The team was tasked with minimizing these burdens either through a new process or by reducing waste in the current process. The primary goal was to decrease the amount of money spent per hour ($75.00), with a secondary goal of increasing throughput (currently$900 hour). The team was given 1 academic year and a budget of $3,000 to design and create a working prototype for Eaton to implement on their factory floor. The group designed and prototyped an automated system that removes a considerable amount of human labor from the job, and with it, creates a large source of revenue which the company can better spend elsewhere. The prototype uses a two dispenser system to minimize jamming and reliably place the tufts for cutting. An electric actuator then pushes the tuft via the end weld bead into the pneumatic cutter. Finally, the cutter splits the tuft in two. The prototype does not currently include a cutting mechanism. The new system decreases costs by 60% and increases total output by 33%. Aside from meeting the primary goal of reducing operator time, the group also met all other design specifications: the prototype has an emergency stop button, was built under budget, requires no PPE, and takes up less than 7 square feet. Eaton expressed their satisfaction with the finalized project and plans on incorporating the design into their seal manufacturing process

Graph coloring with no large monochromatic components

For a graph G and an integer t we let mcc_t(G) be the smallest m such that there exists a coloring of the vertices of G by t colors with no monochromatic connected subgraph having more than m vertices. Let F be any nontrivial minor-closed family of graphs. We show that \mcc_2(G) = O(n^{2/3}) for any n-vertex graph G \in F. This bound is asymptotically optimal and it is attained for planar graphs. More generally, for every such F and every fixed t we show that mcc_t(G)=O(n^{2/(t+1)}). On the other hand we have examples of graphs G with no K_{t+3} minor and with mcc_t(G)=\Omega(n^{2/(2t-1)}). It is also interesting to consider graphs of bounded degrees. Haxell, Szabo, and Tardos proved \mcc_2(G) \leq 20000 for every graph G of maximum degree 5. We show that there are n-vertex 7-regular graphs G with \mcc_2(G)=\Omega(n), and more sharply, for every \epsilon>0 there exists c_\epsilon>0 and n-vertex graphs of maximum degree 7, average degree at most 6+\epsilon for all subgraphs, and with mcc_2(G)\ge c_\eps n. For 6-regular graphs it is known only that the maximum order of magnitude of \mcc_2 is between \sqrt n and n. We also offer a Ramsey-theoretic perspective of the quantity \mcc_t(G).Comment: 13 pages, 2 figure

An Annotated Bibliography of Financial Therapy Research: 2010 to 2018

The purpose of this paper is to expand upon Mentzer, Britt, Samuelson, and Herrera’s (2010) annotated bibliography of research conducted in the field of financial therapy prior to 2010 and provide readers with a current overview of financial therapy research published since that time. Annotated bibliographies are categorized by topics and future research in each area is suggested. In addition, two tables were developed to provide readers a snapshot of the current landscape of financial therapy. The first table provides a list of journals of published articles featuring financial therapy or related topics. The second table provides an overview of types of research, population studies, key topics, as well as highlighting whether theory and financial therapy are overtly referred to within the article

Visual Feedback Dominates the Sense of Agency for Brain-Machine Actions

Recent advances in neuroscience and engineering have led to the development of technologies that permit the control of external devices through real-time decoding of brain activity (brain-machine interfaces; BMI). Though the feeling of controlling bodily movements (sense of agency; SOA) has been well studied and a number of well-defined sensorimotor and cognitive mechanisms have been put forth, very little is known about the SOA for BMI-actions. Using an on-line BMI, and verifying that our subjects achieved a reasonable level of control, we sought to describe the SOA for BMI-mediated actions. Our results demonstrate that discrepancies between decoded neural activity and its resultant real-time sensory feedback are associated with a decrease in the SOA, similar to SOA mechanisms proposed for bodily actions. However, if the feedback discrepancy serves to correct a poorly controlled BMI-action, then the SOA can be high and can increase with increasing discrepancy, demonstrating the dominance of visual feedback on the SOA. Taken together, our results suggest that bodily and BMI-actions rely on common mechanisms of sensorimotor integration for agency judgments, but that visual feedback dominates the SOA in the absence of overt bodily movements or proprioceptive feedback, however erroneous the visual feedback may be

Provision of Mental Health Services by Critical Access Hospital-Based Rural Health Clinics

Residents of rural communities face longstanding access barriers to mental health (MH) services due to chronic shortages of specialty MH providers, long travel distances to services, increased likelihood of being uninsured or under-insured, limited choice of providers, and high rates of stigma. As a result, rural residents rely more heavily on primary care providers and local acute care hospitals to meet their MH needs than do urban residents. This reality highlights the importance of integrating primary care and MH services to improve access to needed care in rural communities. Critical Access Hospitals (CAHs) are ideally positioned to help meet rural MH needs as 60 percent manage at least one Rural Health Clinic (RHC). RHCs receive Medicare cost-based reimbursement for a defined package of services including those provided by doctoral-level clinical psychologists (CPs) and licensed clinical social workers (LCSWs). This briefing paper explores the extent to which CAH-based RHCs are employing CPs and/or LCSWs to provide MH services, describes models of MH services implemented by CAH-based RHCs, examines their successes and challenges in doing so, and provides a resource to assist CAH and RHC leaders in developing MH services. It also provides a resource for State Flex Programs to work with CAH-based RHCs in the development of MH services. FMI: John Gale, [email protected]

Addressing Opioid Use in Rural Communities: Examples from Critical Access Hospitals

The opioid epidemic continues to have a devastating impact in rural areas disproportionately affected by a lack of infrastructure to provide treatment for opioid use disorders (OUDs). Critical Access Hospitals (CAHs), often the hubs of local systems of care, can play an important role in addressing OUDs. Using a substance use framework developed for the Flex Monitoring Team’s earlier study of CAH substance use strategies, this brief highlights strategies adopted by CAHs to combat opioid use in their communities. It also identifies resources that State Flex Programs can use to support CAHs with this challenging population health issue

Engaging Critical Access Hospitals in Addressing Rural Substance Use

Substance use is a significant public health issue in rural communities. Despite this fact, substance use treatment services are limited in rural areas and residents suffer from significant barriers to care. Critical Access Hospitals (CAHs), frequently the hubs of local systems of care, can play an important role in addressing substance use disorders. To develop a coordinated response to community substance use issues, CAHs must identify and prioritize local needs, mobilize local resources and partnerships, build local capacity, and screen for substance use among their patients. These activities provide a foundation upon which CAHs and their community partners can address identified local needs by selecting and implementing initiatives to minimize the onset of substance use and related harms (prevention), treat substance use disorders, and help individuals reclaim their lives (recovery). This brief makes the case for why CAHs should address substance use, provides a framework to support CAHs in doing so, describes examples of substance use activities undertaken by CAHs to substantiate the framework, and identifies resources that can be used by State Flex Programs to support CAHs in addressing this important public and population health problem

Irreversibly increased nitrogen fixation in Trichodesmium experimentally adapted to elevated carbon dioxide

This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nature Communications 6 (2015): 8155, doi:10.1038/ncomms9155.Nitrogen fixation rates of the globally distributed, biogeochemically important marine cyanobacterium Trichodesmium increase under high carbon dioxide (CO2) levels in short-term studies due to physiological plasticity. However, its long-term adaptive responses to ongoing anthropogenic CO2 increases are unknown. Here we show that experimental evolution under extended selection at projected future elevated CO2 levels results in irreversible, large increases in nitrogen fixation and growth rates, even after being moved back to lower present day CO2 levels for hundreds of generations. This represents an unprecedented microbial evolutionary response, as reproductive fitness increases acquired in the selection environment are maintained after returning to the ancestral environment. Constitutive rate increases are accompanied by irreversible shifts in diel nitrogen fixation patterns, and increased activity of a potentially regulatory DNA methyltransferase enzyme. High CO2-selected cell lines also exhibit increased phosphorus-limited growth rates, suggesting a potential advantage for this keystone organism in a more nutrient-limited, acidified future ocean.Grant support was provided by U.S. National Science Foundation OCE 1260490 and OCE 1143760 to D.A.H., E.A.W., and F.-X.F, and OCE 1260233, OCE OA 1220484, and G.B. Moore Foundation 3782 and 3934 to M.A.S.© The Author(s), [year]