Showing papers by "Clarkson University published in 2016"

Plasma-liquid interactions: A review and roadmap

Abstract: Plasma–liquid interactions represent a growing interdisciplinary area of research involving plasma science, fluid dynamics, heat and mass transfer, photolysis, multiphase chemistry and aerosol science. This review provides an assessment of the state-of-the-art of this multidisciplinary area and identifies the key research challenges. The developments in diagnostics, modeling and further extensions of cross section and reaction rate databases that are necessary to address these challenges are discussed. The review focusses on non-equilibrium plasmas.

Ambient Air Pollution Exposure Estimation for the Global Burden of Disease 2013

Abstract: Exposure to ambient air pollution is a major risk factor for global disease. Assessment of the impacts of air pollution on population health and evaluation of trends relative to other major risk factors requires regularly updated, accurate, spatially resolved exposure estimates. We combined satellite-based estimates, chemical transport model simulations, and ground measurements from 79 different countries to produce global estimates of annual average fine particle (PM2.5) and ozone concentrations at 0.1° × 0.1° spatial resolution for five-year intervals from 1990 to 2010 and the year 2013. These estimates were applied to assess population-weighted mean concentrations for 1990-2013 for each of 188 countries. In 2013, 87% of the world's population lived in areas exceeding the World Health Organization Air Quality Guideline of 10 μg/m(3) PM2.5 (annual average). Between 1990 and 2013, global population-weighted PM2.5 increased by 20.4% driven by trends in South Asia, Southeast Asia, and China. Decreases in population-weighted mean concentrations of PM2.5 were evident in most high income countries. Population-weighted mean concentrations of ozone increased globally by 8.9% from 1990-2013 with increases in most countries-except for modest decreases in North America, parts of Europe, and several countries in Southeast Asia.

Genetic variants associated with subjective well-being, depressive symptoms, and neuroticism identified through genome-wide analyses

Abstract: Very few genetic variants have been associated with depression and neuroticism, likely because of limitations on sample size in previous studies. Subjective well-being, a phenotype that is genetically correlated with both of these traits, has not yet been studied with genome-wide data. We conducted genome-wide association studies of three phenotypes: subjective well-being (n = 298,420), depressive symptoms (n = 161,460), and neuroticism (n = 170,911). We identify 3 variants associated with subjective well-being, 2 variants associated with depressive symptoms, and 11 variants associated with neuroticism, including 2 inversion polymorphisms. The two loci associated with depressive symptoms replicate in an independent depression sample. Joint analyses that exploit the high genetic correlations between the phenotypes (|ρ^| ≈ 0.8) strengthen the overall credibility of the findings and allow us to identify additional variants. Across our phenotypes, loci regulating expression in central nervous system and adrenal or pancreas tissues are strongly enriched for association.

Ambient air pollution exposure estimation for the global burden of disease 2013

Abstract: Exposure to ambient air pollution is a major risk factor for global disease. Assessment of the impacts of air pollution on population health and the evaluation of trends relative to other major risk factors requires regularly updated, accurate, spatially resolved exposure estimates. We combined satellite-based estimates, chemical transport model (CTM) simulations and ground measurements from 79 different countries to produce new global estimates of annual average fine particle (PM2.5) and ozone concentrations at 0.1° × 0.1° spatial resolution for five-year intervals from 1990-2010 and the year 2013. These estimates were then applied to assess population-weighted mean concentrations for 1990 – 2013 for each of 188 countries. In 2013, 87% of the world’s population lived in areas exceeding the World Health Organization (WHO) Air Quality Guideline of 10 μg/m3 PM2.5 (annual average). Between 1990 and 2013, decreases in population-weighted mean concentrations of PM2.5 were evident in most high income countries, in contrast to increases estimated in South Asia, throughout much of Southeast Asia, and in China. Population-weighted mean concentrations of ozone increased in most countries from 1990 - 2013, with modest decreases in North America, parts of Europe, and several countries in Southeast Asia.

Review of receptor modeling methods for source apportionment

Abstract: Efforts have been made to relate measured concentrations of airborne constituents to their origins for more than 50 years. During this time interval, there have been developments in the measurement technology to gather highly time-resolved, detailed chemical compositional data. Similarly, the improvements in computers have permitted a parallel development of data analysis tools that permit the extraction of information from these data. There is now a substantial capability to provide useful insights into the sources of pollutants and their atmospheric processing that can help inform air quality management options. Efforts have been made to combine receptor and chemical transport models to provide improved apportionments. Tools are available to utilize limited numbers of known profiles with the ambient data to obtain more accurate apportionments for targeted sources. In addition, tools are in place to allow more advanced models to be fitted to the data based on conceptual models of the nature of th...

Sea spray aerosol as a unique source of ice nucleating particles

Abstract: Ice nucleating particles (INPs) are vital for ice initiation in, and precipitation from, mixed-phase clouds. A source of INPs from oceans within sea spray aerosol (SSA) emissions has been suggested in previous studies but remained unconfirmed. Here, we show that INPs are emitted using real wave breaking in a laboratory flume to produce SSA. The number concentrations of INPs from laboratory-generated SSA, when normalized to typical total aerosol number concentrations in the marine boundary layer, agree well with measurements from diverse regions over the oceans. Data in the present study are also in accord with previously published INP measurements made over remote ocean regions. INP number concentrations active within liquid water droplets increase exponentially in number with a decrease in temperature below 0 °C, averaging an order of magnitude increase per 5 °C interval. The plausibility of a strong increase in SSA INP emissions in association with phytoplankton blooms is also shown in laboratory simulations. Nevertheless, INP number concentrations, or active site densities approximated using "dry" geometric SSA surface areas, are a few orders of magnitude lower than corresponding concentrations or site densities in the surface boundary layer over continental regions. These findings have important implications for cloud radiative forcing and precipitation within low-level and midlevel marine clouds unaffected by continental INP sources, such as may occur over the Southern Ocean.

Distributed Generation Hosting Capacity Evaluation for Distribution Systems Considering the Robust Optimal Operation of OLTC and SVC

Abstract: With the rapidly increasing penetration of renewable distributed generation (DG), the maximum hosting capacity (MHC) of a distribution system has become a major concern. To effectively evaluate the ability of a distribution system to accommodate DGs, this paper proposes an MHC evaluation method while considering the robust optimal operation of on load tap changers (OLTCs) and static var compensators (SVCs) in the uncertain context of DG power outputs and load consumptions. The proposed method determines the DG hosting capacities corresponding to different conservative levels. Furthermore, this paper discusses how to find out the most critical technical constraint that may limit the MHC by adjusting parameters of the proposed robust formulation. The effectiveness of the proposed method is demonstrated using a modified IEEE 33-bus distribution system.

How Should Genes and Taxa be Sampled for Phylogenomic Analyses with Missing Data? An Empirical Study in Iguanian Lizards

Abstract: Targeted sequence capture is becoming a widespread tool for generating large phylogenomic data sets to address difficult phylogenetic problems. However, this methodology often generates data sets in which increasing the number of taxa and loci increases amounts of missing data. Thus, a fundamental (but still unresolved) question is whether sampling should be designed to maximize sampling of taxa or genes, or to minimize the inclusion of missing data cells. Here, we explore this question for an ancient, rapid radiation of lizards, the pleurodont iguanians. Pleurodonts include many well-known clades (e.g., anoles, basilisks, iguanas, and spiny lizards) but relationships among families have proven difficult to resolve strongly and consistently using traditional sequencing approaches. We generated up to 4921 ultraconserved elements with sampling strategies including 16, 29, and 44 taxa, from 1179 to approximately 2.4 million characters per matrix and approximately 30% to 60% total missing data. We then compared mean branch support for interfamilial relationships under these 15 different sampling strategies for both concatenated (maximum likelihood) and species tree (NJst) approaches (after showing that mean branch support appears to be related to accuracy). We found that both approaches had the highest support when including loci with up to 50% missing taxa (matrices with ~40-55% missing data overall). Thus, our results show that simply excluding all missing data may be highly problematic as the primary guiding principle for the inclusion or exclusion of taxa and genes. The optimal strategy was somewhat different for each approach, a pattern that has not been shown previously. For concatenated analyses, branch support was maximized when including many taxa (44) but fewer characters (1.1 million). For species-tree analyses, branch support was maximized with minimal taxon sampling (16) but many loci (4789 of 4921). We also show that the choice of these sampling strategies can be critically important for phylogenomic analyses, since some strategies lead to demonstrably incorrect inferences (using the same method) that have strong statistical support. Our preferred estimate provides strong support for most interfamilial relationships in this important but phylogenetically challenging group.

Excellent energy–power characteristics from a hybrid sodium ion capacitor based on identical carbon nanosheets in both electrodes

Abstract: We created a hybrid Na ion capacitor (NIC) with a unique architecture and exceptional energy–power characteristics. Both the anode and the cathode are based on peanut skin derived carbon nanosheets fabricated by simultaneous carbonization and activation or by carbonization alone. The tens of nanometer thick (down to 20 nm) – high surface area (up to 2070 m2 g−1) nanosheets possesses a disordered structure for copious reversible binding of Na at the carbon defects. They are also hierarchically micro–meso–macro porous, allowing facile ion transport at high rates both through the pore-filling electrolyte and in the solid-state. When employed as sodium ion battery anode, the carbon shows a tremendous reversible (desodiation) capacity of 461 mA h g−1 at 100 mA g−1 and excellent rate capability, e.g. 107 mA h g−1 at 5 A g−1. The optimized NIC device displays highly favorable Ragone chart placement, e.g. 112 and 45 W h kg−1 at 67 and 12 000 W kg−1, retaining 85% of its capacity after 3000 cycles.

Robust SCUC Considering Continuous/Discrete Uncertainties and Quick-Start Units: A Two-Stage Robust Optimization With Mixed-Integer Recourse

Abstract: This paper presents a comprehensive two-stage robust security-constrained unit commitment (SCUC) approach, which minimizes the operation cost of the base case while guaranteeing that the robust solution can be adaptively and securely adjusted in response to continuous load and wind uncertainty intervals as well as discrete $N-K$ generation and transmission contingency security criteria. In addition, corrective capabilities of both non-quick-start and quick-start units are rigorously formulated. Specifically, unit commitment of quick-start units is adaptively adjusted in the recourse stage for satisfying security constraints under various uncertainties, which introduces mixed-integer recourse to the proposed two-stage robust SCUC model. The proposed model is solved by the combination of modified Benders decomposition (BD) method and column-and-constraint generation (C&CG) algorithm, which decompose the original problem into a master UC problem for the base case and security checking subproblems for uncertainties. Numerical case studies on the modified IEEE 118-bus system illustrate the effectiveness of the proposed robust SCUC approach. Although the modified BD does not provide the tightest lower bound and may not guarantee the global optimality, robustness performance tests indicate that a reasonable threshold on the violation of security checking subproblems would guarantee good enough solutions from engineering point of view.

Children with Autism Spectrum Disorder and Social Skills Groups at School: A Randomized Trial Comparing Intervention Approach and Peer Composition.

Abstract: Background Peer relationships improve for children with autism spectrum disorder (ASD) in clinic-based social skills groups but rarely generalize to real world contexts. This study compares child outcomes of two social skills interventions conducted in schools with children in Kindergarten through fifth grade. Method Children with ASD were randomized to one of two interventions that varied on group composition (mixed typical and ASD vs. all ASD or social difficulties) and intervention approach (didactic SKILLS based vs. activity-based ENGAGE groups). Interventions were implemented at school for 8 weeks (16 sessions) with an 8-week follow-up. Innovative measures of peer nomination and playground peer engagement, as well as teacher reports of child behavior problems and teacher–child relationship were analyzed for 137 children with ASD across four sites. Results On the primary outcome of social network connections from the peer nomination measure, there was no main effect of treatment, but there were moderator effects. Children with low teacher–child closeness or high conflict improved more in their social connections if they received the SKILLS intervention, whereas children with higher teacher–child closeness improved more if they received the ENGAGE intervention. Only two secondary outcome measures yielded significant effects of treatment. Children in the SKILLS groups increased peer engagement and decreased isolation during recess. Child behavior problems and teacher–child closeness moderated peer engagement such that children with higher behavior problems and lower closeness benefitted more from SKILLS groups. Conclusions These findings suggest that social skills groups conducted at school can affect both peer engagement during recess as well as peer acceptability. Child characteristics and teacher–child relationship prior to intervention yield important information on who might benefit from a specific social skills intervention.

Anchor-Assisted and Vote-Based Trustworthiness Assurance in Smart City Crowdsensing

Abstract: Smart city sensing calls for crowdsensing via mobile devices that are equipped with various built-in sensors. As incentivizing users to participate in distributed sensing is still an open research issue, the trustworthiness of crowdsensed data is expected to be a grand challenge if this cloud-inspired recruitment of sensing services is to be adopted. Recent research proposes reputation-based user recruitment models for crowdsensing; however, there is no standard way of identifying adversaries in smart city crowdsensing. This paper adopts previously proposed vote-based approaches, and presents a thorough performance study of vote-based trustworthiness with trusted entities that are basically a subset of the participating smartphone users. Those entities are called trustworthy anchors of the crowdsensing system. Thus, an anchor user is fully trustworthy and is fully capable of voting for the trustworthiness of other users, who participate in sensing of the same set of phenomena. Besides the anchors, the reputations of regular users are determined based on vote-based (distributed) reputation. We present a detailed performance study of the anchor-based trustworthiness assurance in smart city crowdsensing through simulations, and compare it with the purely vote-based trustworthiness approach without anchors, and a reputation-unaware crowdsensing approach, where user reputations are discarded. Through simulation findings, we aim at providing specifications regarding the impact of anchor and adversary populations on crowdsensing and user utilities under various environmental settings. We show that significant improvement can be achieved in terms of usefulness and trustworthiness of the crowdsensed data if the size of the anchor population is set properly.

Cloud-centric multi-level authentication as a service for secure public safety device networks

Abstract: With the advances in IoT, future public safety responders will be well armed with devices that pump data between on-site responders and command centers, carrying useful information about the event scene, the status of a mission, and helping critical decisions to be made in real time. In addition, wearable and on-body sensors will monitor the vital signals and well being of the responders. These connected devices or the so-called IoT surrounding public safety responders generate highly vulnerable data, where security breaches may have life threatening consequences. Authentication of responder devices is essential in order to control access to public safety networks. Most of the existing authentication schemes do not scale well with the large number of devices of IoT, and are not fast enough to work during time-critical public safety missions. On the other hand, for general IoT services, cloud-based solutions provide unlimited resources for storing and accessing IoT data. However, the cloud may have some implications for sensitive data that are collected for public safety. Therefore, authentication solutions are desired to integrate well into the cloud environment. In this article, we propose cloud-centric, multi-level authentication as a service approach that addresses scalability and time constraints, and demonstrate its effectiveness. We draw future research directions for secure public safety networks in the presence of IoT devices and the cloud.

A Survey on Cross-Layer Quality-of-Service Approaches in WSNs for Delay and Reliability-Aware Applications

Abstract: Using wireless sensor networks (WSNs) in delay and reliability critical environments is highly desired due to their unique advantages such as low cost, ease of deployment, and redundancy. However, successful deployment of resource-limited WSNs in such applications requires strict quality-of-service (QoS) provisioning techniques to meet the desired latency and reliability targets of those applications. Implementation of QoS techniques in WSNs is significantly challenging since WSNs have been initially devised for low-data-rate non-real-time applications. Therefore, WSN designers and developers resort to different cross-layer interaction and optimization techniques to provision QoS in WSNs. In this paper, we present a survey on the state of the art of cross-layer QoS approaches in wireless terrestrial sensor networks to achieve delay and reliability bounds in critical applications. Our paper provides a unique classification of cross-layer QoS approaches in WSNs that allows surveying a large amount of studies with utmost clarity. Furthermore, we highlight the main challenges of implementing QoS protocols in WSNs and present an overview of QoS-aware WSN applications.

Prevalence, injury rate and, symptom frequency in generalized joint laxity and joint hypermobility syndrome in a "healthy" college population.

Abstract: Generalized joint hypermobility (GJH) and joint hypermobility syndrome (JHS) are gaining increased attention as potential sources of pain and injury. The aims of this study were to evaluate prevalence of GJH and JHS and to determine whether musculoskeletal injuries and symptoms commonly attributed to GJH and JHS were more common within a “healthy” college student population. The study involved a convenience sample of 267 college and graduate students, aged 17–26. GJH was assessed using the Beighton score with a cutoff of 5/9, while JHS was assessed using the Brighton criteria. Injury history and symptoms were assessed by recall. Prevalence of GJH was 26.2 % overall (females 36.7 %, males 13.7 %). Prevalence of JHS was 19.5 % overall (females 24.5 %, males 13.7 %). Injury rates were not significantly different for individuals who had GJH vs. those who did not have GJH. Individuals with JHS were significantly more likely to have had sprains, back pain, and stress fractures. Symptoms were no different between those with GJH and those who did not have GJH. However, individuals with JHS were significantly more likely to report clumsiness, easy bruising, and balance problems than those who did not have JHS. GJH and JHS were relatively common in this healthy college student population; GJH was not associated with increased incidence of injury or symptoms commonly attributed to JHS, but JHS was associated with increased incidence of some injuries and symptoms.

Dissipation of wind waves by pancake and frazil ice in the autumn Beaufort Sea

Abstract: A model for wind-generated surface gravity waves, WAVEWATCH IIIR , is used to analyze and interpret buoy measurements of wave spectra. The model is applied to a hindcast of a wave event in sea ice in the western Arctic, 11–14 October 2015, for which extensive buoy and ship-borne measurements were made during a research cruise. The model, which uses a viscoelastic parameterization to represent the impact of sea ice on the waves, is found to have good skill—after calibration of the effective viscosity—for prediction of total energy, but over-predicts dissipation of high frequency energy by the sea ice. This shortcoming motivates detailed analysis of the apparent dissipation rate. A new inversion method is applied to yield, for each buoy spectrum, the inferred dissipation rate as a function of wave frequency. For 102 of the measured wave spectra, visual observations of the sea ice were available from buoy-mounted cameras, and ice categories (primarily for varying forms of pancake and frazil ice) are assigned to each based on the photographs. When comparing the inversion-derived dissipation profiles against the independently derived ice categories, there is remarkable correspondence, with clear sorting of dissipation profiles into groups of similar ice type. These profiles are largely monotonic: they do not exhibit the ‘‘roll-over’’ that has been found at high frequencies in some previous observational studies.

Antibacterial and photocatalytic degradation efficacy of silver nanoparticles biosynthesized using Cordia dichotoma leaf extract

Abstract: The present study focuses on the biosynthesis of silver nanoparticles (AgNPs) along with its antibacterial and photocatalytic activity. The AgNPs were synthesized using Cordia dichotoma leaf extract and were characterized using UV-vis spectroscopy to determine the formation of AgNPs. FTIR was done to discern biomolecules responsible for reduction and capping of the synthesized nanoparticles. Further, DLS technique was performed to examine its hydrodynamic diameter, followed by SEM, TEM and XRD to determine its size, morphology and crystalline structure. Later, these AgNPs were studied for their potential role in antibacterial activity and photocatalytic degradation of azo dyes such as methylene blue and Congo red.

Dignity, face, and honor cultures: A study of negotiation strategy and outcomes in three cultures

Abstract: Summary This study compares negotiation strategy and outcomes in countries illustrating dignity, face, and honor cultures. Hypotheses predict cultural differences in negotiators' aspirations, use of strategy, and outcomes based on the implications of differences in self-worth and social structures in dignity, face, and honor cultures. Data were from a face-to-face negotiation simulation; participants were intra-cultural samples from the USA (dignity), China (face), and Qatar (honor). The empirical results provide strong evidence for the predictions concerning the reliance on more competitive negotiation strategies in honor and face cultures relative to dignity cultures in this context of negotiating a new business relationship. The study makes two important theoretical contributions. First, it proposes how and why people in a previously understudied part of the world, that is, the Middle East, use negotiation strategy. Second, it addresses a conundrum in the East Asian literature on negotiation: the theory and research that emphasize the norms of harmony and cooperation in social interaction versus empirical evidence that negotiations in East Asia are highly competitive. Copyright © 2016 John Wiley & Sons, Ltd.

Heat Transfer and Pressure Drop in Fully Developed Turbulent Flows of Graphene Nanoplatelets-Silver/Water Nanofluids

Abstract: This study examined the heat transfer coefficient, friction loss, pressure drop and pumping power needed for the use of nanofluid coolants made of a mixture of suspension of graphene nanoplatelets–silver in water in a rectangular duct. A series of calculations were performed for the coolant volume flow rate in the range of 5000 ≤ Re ≤ 15,000 under a fully developed turbulent flow regime and different nanosheet concentrations up to 0.1 weight percent. The thermo-physical properties of the nanofluids were extracted from the recent experimental work of Yarmand et al. (Graphene nanoplatelets-silver hybrid nanofluids for enhanced heat transfer. Energy Convers. Manag. 2015, 100, 419–428). The presented results indicated that the heat transfer characteristics of the nanofluid coolants improved with the increase in nanosheet concentration as well as the increase in the coolant Reynolds number. However, there was a penalty in the duct pressure drop and an increase in the required pumping power. In summary, the closed conduit heat transfer performance can be improved with the use of appropriate nanofluids based on graphene nanoplatelets–silver/water as a working fluid.