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Hanson L.S.,Tufts University | Hanson L.S.,CNA Corporation | Vogel R.M.,Tufts University
Environmental Research Letters | Year: 2014

Sizing storage for rainwater harvesting (RWH) systems is often a difficult design consideration, as the system must be designed specifically for the local rainfall pattern. We introduce a generally applicable method for estimating the required storage by using regional regression equations to account for climatic differences in the behavior of RWH systems across the entire continental United States. A series of simulations for 231 locations with continuous daily precipitation records enable the development of storage-reliability-yield (SRY) relations at four useful reliabilities, 0.8, 0.9, 0.95, and 0.98. Multivariate, log-linear regression results in storage equations that include demand, collection area and local precipitation statistics. The continental regression equations demonstrated excellent goodness-of-fit (R2 0.96-0.99) using only two precipitation parameters, and fits improved when three geographic regions with more homogeneous rainfall characteristics were considered. The SRY models can be used to obtain a preliminary estimate of how large to build a storage tank almost anywhere in the United States based on desired yield and reliability, collection area, and local rainfall statistics. Our methodology could be extended to other regions of world, and the equations presented herein could be used to investigate how RWH systems would respond to changes in climatic variability. The resulting model may also prove useful in regional planning studies to evaluate the net benefits which result from the broad use of RWH to meet water supply requirements. We outline numerous other possible extensions to our work, which when taken together, illustrate the value of our initial generalized SRY model for RWH systems. © 2014 IOP Publishing Ltd. Source

Ozdemir A.,Michigan State University | Bolanos M.,CNA Corporation | Bernat E.,University of Maryland University College | Aviyente S.,Michigan State University
IEEE Transactions on Biomedical Engineering | Year: 2015

A central question in cognitive neuroscience is how cognitive functions depend on the integration of specialized widely distributed brain regions. In recent years, graph theoretical methods have been used to characterize the structure of the brain functional connectivity. In order to understand the organization of functional connectivity networks, it is important to determine the community structure underlying these complex networks. Moreover, the study of brain functional networks is confounded by the fact that most neurophysiological studies consists of data collected from multiple subjects; thus, it is important to identify communities representative of all subjects. Typically, this problem is addressed by averaging the data across subjects which omits the variability across subjects or using voting methods, which requires a priori knowledge of cluster labels. In this paper, we propose a hierarchical consensus spectral clustering approach to address these problems. Furthermore, new information-theoretic criteria are introduced for selecting the optimal community structure. The proposed framework is applied to electroencephalogram data collected during a study of error-related negativity to better understand the community structure of functional networks involved in the cognitive control. © 1964-2012 IEEE. Source

Newby J.J.,Purdue University | Legg M.A.,CNA Corporation | Rogers B.,Purdue University | Wirth M.J.,Purdue University
Journal of Chromatography A | Year: 2011

Non-porous, colloidal silica particles were annealed at three different temperatures, 800, 900 and 1050 °C. The adsorption of lysozyme, a probe of surface roughness, was consistent with progressively reduced surface roughness as temperature increased. The heat treated silica particles were rehydroxylated and then used to pack UHPLC columns. The cationic protein lysozyme was used to probe silanol activity, which exhibited progressively less tailing as the annealing temperature increased. FTIR spectroscopy confirmed that the abundance of isolated silanols on the surface was reduced by annealing at 900 °C or 1050 °C. FTIR also revealed that there was markedly increased hydrogen bonding of the isolated silanols to neighbors after rehydroxylation. These results combine to support the hypothesis that (a) isolated silanols on silica cause tailing in RP-LC and (b) nonplanar topography gives rise to isolated silanols. © 2011 Elsevier B.V. Source

King M.D.,CNA Corporation
NATO Science for Peace and Security Series C: Environmental Security | Year: 2012

The first section of the paper presents key findings from the 2007 report, National Security and the Threat of Climate Change by the CNA Corporation, including that projected climate change: (1) Poses a serious threat to U.S. National Security; (2) Acts as a threat multiplier for instability in some of the most volatile regions in the world and; (3) Adds tensions even in stable regions of the world. In the second section I summarize work conducted by myself and Dr. Ralph Espach at CNA that identifies exactly which countries are most relevant to the CNA Military Advisory Board's original findings. By compiling data from a variety of sources, we identify the states most exposed to the impacts of climate change both in the short and long term. The next section introduces estimates of the resilience of these countries, and combines our evaluation of country exposure and expected resilience to create a 3-tiered ranking of countries most vulnerable to political and/or humanitarian crises as a result of climate impacts. © Springer Science+Business Media B.V. 2012. Source

Sarfaty M.,Thomas Jefferson University | Stello B.,Lehigh Valley Health Network and Eastern Pennsylvania Inquiry Collaborative Network | Johnson M.,Lehigh Valley Health Network and Eastern Pennsylvania Inquiry Collaborative Network | Sifri R.,Thomas Jefferson University | And 2 more authors.
American Journal of Medical Quality | Year: 2013

A recent report from a survey of 15 primary care practices revealed considerable variability and much room for improvement in aspects of primary care practice that are associated with increased colorectal cancer screening rates. There was low utilization of patient reminders, tracking of test completion, rescheduling of missed appointments, and inconsistent follow-up of positive stool blood tests. Qualitative data collected in the same study provide insights into how the practices operated. Focus group discussions with the clinicians and staff of the practices and key informant interviews with office managers support the survey findings by shedding light on a lack of office policies and systems. Many practices lacked a systematic way to identify patients who were not up to date on screening while they were visiting the practice, thereby passing up the best opportunity to reach them. These findings are not consistent with the patient-centered medical home model. © 2013 by the American College of Medical Quality. Source

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