Studies of electrical resistivity in thin metallic films at low temperature

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Surveillance of South Dakota Mosquito Abundance, Infection Rate, and Insecticide Susceptibility

The aim of this dissertation was to survey and evaluate the abundance, infection rate, and insecticide susceptibility of mosquito fauna present in South Dakota. Mosquito surveillance has been conducted across South Dakota to record and track potential West Nile virus (WNV) vectors from 2004 to 2017. The nuisance mosquito Aedes vexans was found to be the most abundant species overall in the state and most abundant in many of the regions. The WNV vector, Culex tarsalis, was found to be the second most abundant mosquito and the most abundant vector mosquito across the state. However, geospatial variation did exist between both the vector and nuisance, as well as between different WNV vectors latitudinally across the state. A total of 22 mosquito species were identified, and 6 were found each year. Positive relationships were found between average Cx. tarsalis weekly abundance and average weekly human cases of WNV at a two to three-week lag. Weaker relationships existed between Ae. vexans and human cases of WNV and between the ratio of Cx. tarsalis to total mosquito abundance and human cases of WNV. We were not able to identify any relationship between yearly vector abundance and human cases. Logistic regression modeling using mean daily temperatures and total daily precipitation determined the best weekly collection period for collections to have the highest proportion of Cx. tarsalis. Infection rates of potential mosquito vectors were calculated using the minimum infection rate method. Though Cx. tarsalis infection rate was lower than other present vector species, due to its large relative abundance to other highly susceptible species it is still considered to be the primary method for human WNV infection. In testing susceptibility to the insecticide permethrin, we determined the diagnostic dose for multiple time periods and ranged from 27.0 μg/ml at 60 min to 38.4 μg/ml at 30 min. There was no significant difference detected in mortality rates between Cx. tarsalis and Ae. vexans for any diagnostic time and dose. For practical purposes, mosquitoes in 2017 were tested at 38 μg/ml for 30 min; expected mortality rates were 93.38% for Cx. tarsalis and 94.93% for Ae. vexans. Actual 2017 mortality rates were 92.68% for Cx. tarsalis and 96.12% for Ae. vexans, validating the usefulness of this baseline at an additional location and year. These findings suggest that mosquito control efforts are not selectively diminishing nuisance mosquitoes that may contribute to human avoidance behaviors that may limit exposure to WNV. These base line time and diagnostic values can allow for future studies to monitor these two important South Dakota mosquito species for resistance to insecticides

Game Theoretic Approaches to Massive Data Processing in Wireless Networks

Wireless communication networks are becoming highly virtualized with two-layer hierarchies, in which controllers at the upper layer with tasks to achieve can ask a large number of agents at the lower layer to help realize computation, storage, and transmission functions. Through offloading data processing to the agents, the controllers can accomplish otherwise prohibitive big data processing. Incentive mechanisms are needed for the agents to perform the controllers' tasks in order to satisfy the corresponding objectives of controllers and agents. In this article, a hierarchical game framework with fast convergence and scalability is proposed to meet the demand for real-time processing for such situations. Possible future research directions in this emerging area are also discussed

The effects of recent austerity on environmental protection decisions:evidence and perspectives from Scotland

Purpose: The purpose of this paper is to establish the evidence for, the why and how recent austerity policy atmosphere associated with the UK government affected environmental protection decisions within planning in Scotland. Design/methodology/approach: A qualitative analysis based on perspectives gathered via questionnaire survey targeted at stakeholders involved in planning in Scotland was undertaken. The questionnaire responses were analysed thematically, supplemented by using statistical tests of significance and variance to show how responses differed across participants. Findings: The evidence showed that austerity policy atmosphere resulted in a pervasive neoliberal imperative of resuscitating the economy; whilst producing subtle and adverse effects on environmental decisions. This was best understood within a neo-Gramscian perspective of hegemony, borrowed from the field of political economy of states. Research limitations/implications: The gathered views were constrained within unknown biases that the participants may have had; and because the case study approach was not equipped to generalize the results beyond the study, more research testing cause-effect between the austerity and selected environmental parameters is needed, from various contexts. Practical implications: Decision-making frameworks should explicitly acknowledge the unique pressures during austerity periods; and contemplate resilient decision-making frameworks that can withstand the hegemonic tendencies which prioritise economic goals above environmental ones. Originality/value: Whilst the area of austerity’s impacts on the environment remains poorly evidenced, empirically, this seminal paper uses robust analysis to establish how the austerity policy atmosphere affects environmental decisions. This is insight into what may be happening in other similar situations outside Scotland, raising concern as to whether and how we should approach the challenge of hegemonic ideas

High Altitude Launch for a Practical SSTO

Existing engineering materials allow the construction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. high-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2% of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated in to increased payload capability to orbit, ranging from 5 to 20% increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2% of gross lift-off weight, this corresponds to 31 % increase in payload (for 5-km launch altitude) to 122% additional payload (for 25-km launch altitude)

High Altitude Launch for a Practical SSTO

Existing engineering materials allow the construction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. High-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2 percent of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated into increased payload capability to orbit, ranging from 5 to 20 percent increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2 percent of gross lift-off weight, this corresponds to 31 percent increase in payload (for 5-kilometer launch altitude) to 122 percent additional payload (for 25-kilometer launch altitude)

Ion-Molecule Reactions in Unsaturated Hydrocarbons: Allene, Propyne, Diacetylene, and Vinylacetylene

Ion-molecule reactions in allene, propyne, diacetylene, and vinylacetylene (1-buten-3-yne) have been studied at near-thermal energies by the technique of ion cyclotron resonance mass spectrometry. Rate coefficients and branching ratios are reported for the reactions of C_3H^+_n (n = 1-4) with allene and propyne and for the reactions of C_4H^+_n (n = 0-5) with diacetylene and vinylacetylene. Branching ratios are also given for the reactions of C_4H^+_n, C_5H_n, and C_6H^+_n with propyne and for reactions of C_6H^+_n with diacetylene and vinylacetylene. More than 90% of the reactive channels lead to product ions having a larger carbon skeleton than the reactant ion. Evidence for ions with the same m/e ratio having differing reactivities was obtained for C_3H^+_3, C_6H^+_7, and C_7H^+_7. Ion reaction sequences in allene and propyne were followed at higher pressures (l0^(-4) torr) to investigate secondary, tertiary, and higher order processes

Timing Analysis of Fixed Priority SelfSuspending Sporadic Tasks

27th Euromicro Conference on Real-Time Systems (ECRTS 2015), Lund, Sweden.Many real-time systems include tasks that need to suspend their execution in order to externalize some of their operations or to wait for data, events or shared resources. Although commonly encountered in real-world systems, study of their timing analysis is still limited due to the problem complexity. In this paper, we invalidate a claim made in one of the earlier works [1], that led to the common belief that the timing analysis of one self-suspending task interacting with non-self-suspending sporadic tasks is much easier than in the periodic case. This work highlights the complexity of the problem and presents a method to compute the exact worst-case response time (WCRT) of a self-suspending task with one suspension region. However, as the complexity of the analysis might rapidly grow with the number of tasks, we also define an optimization formulation to compute an upper-bound on the WCRT for tasks with multiple suspendion regions. In the experiments, our optimization framework outperforms all previous analysis techniques and often finds the exact WCRT