10 research outputs found

    Effective Scheduling of Road and Bridge Closures: Phase 2

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    This research provides a study on work zone impact analysis. In case of multiple road closures, the network approach is used to find an effective scheduling such that the total user delay is reduced. A dynamic model for analyzing the work zone impact during the period when network is in transition state is also developed. A salient feature of the dynamic model is drives’ perception updating model, which incorporates availability and the quality of information as perceived by drivers

    Emerging Roles of L-Type Voltage-Gated and Other Calcium Channels in T Lymphocytes

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    In T lymphocytes, calcium ion controls a variety of biological processes including development, survival, proliferation, and effector functions. These distinct and specific roles are regulated by different calcium signals, which are generated by various plasma membrane calcium channels. The repertoire of calcium-conducting proteins in T lymphocytes includes store-operated CRAC channels, transient receptor potential (TRP) channels, P2X channels, and L-type voltage-gated calcium (Cav1) channels. In this paper, we will focus mainly on the role of the Cav1 channels found expressed by T lymphocytes, where these channels appear to operate in a TCR stimulation-dependent and voltage-sensor independent manner. We will review their expression profile at various differentiation stages of CD4 and CD8 T lymphocytes. Then, we will present crucial genetic evidence in favor of a role of these Cav1 channels and related regulatory proteins in both CD4 and CD8 T cell functions such as proliferation, survival, cytokine production and cytolysis. Finally, we will provide evidence and speculate on how these voltage-gated channels might function in the T lymphocyte, a non-excitable cell

    Day-to-day travel choice dynamics in transportation networks: Models and computational issues

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    A Bayesian updating model is developed to capture the mechanism by which travelers update their travel time perceptions from one day to the next in light of information provided by Advanced Traveler Information Systems (ATIS) and their previous experience. The availability and perceived quality of traffic information are explicitly modeled within the proposed framework. The development of the framework is motivated by the need to predict travelers\u27 response to different information supply strategies. The perception updating model and the choice model are integrated with a dynamic traffic simulator (DYNASMART). A simulation framework for studying perception updating and day-to-day travel choice dynamics in presence of ATIS is also developed. For an efficient implementation of a detailed driver behavior model and other Dynamic Traffic Assignment (DTA) models, an agent based framework for solving ATIS/ATMS operations is developed. Within the overall distributed framework, two models are proposed for distributed traffic simulation. The proposed distributed models do not depend on hardware capability for speed-up and hence they are useful from the practical standpoint. Simulation experiments were carried out on the basis of the proposed framework. The results from these experiments are in conformity with some of the previous studies. In addition to modeling the mechanism by which drivers revise their perceptions from one day to the next in light of travel time information and experienced travel time, two important issues that were addressed in this thesis were: (a) the impact of the utility function; and (b) the existence of a steady-state in the network. It was found that the parameters of the utility function can have substantial impact on the network traffic pattern. Another significant result from the empirical study of the model was that overall departure rates as well as time dependent traffic patterns on individual links reached a steady state after some time. A preliminary implementation of the distributed model was also performed with DYNASMART. A large number of communication calls was needed to synchronize the simulation. Due to a very high communication latency of the Ethernet network, the communication overhead negated the advantage of the distributed system

    Ultrasonic assisted <i>in situ </i>transesterification of Jatropha seed to biodiesel

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    290-294This study presents a laboratory scale process for in-situ transesterification of Jatropha seeds to biodiesel under ultrasonic irradiation. Biodiesel with best yield and quality was produced at following conditions: seed/methanol (w/v) ratio, 1:10; reaction time, 80 min; and catalyst conc., 1% (w/w)
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