Development of System Analysis Methodologies and Tools for Modeling and Optimizing Vehicle System Efficiency.

Optimizing the vehicle system is essential for achieving higher fuel efficiency. This dissertation addresses the need to better understand energy demand from a vehicle subsystem standpoint and tackles the challenge of optimal hardware and control system design. An energy analysis methodology and Matlab®/Simulink® based tool are developed to account for where the fuel energy supplied to a vehicle system is demanded. A hybrid semi-empirical and analytical approach that combines first principles with detailed component speed and load data is proposed. The methodology and tool are applied to account for the instantaneous and accumulated vehicle subsystem energy usage over a given drive cycle. A comparison of the prevailing fuel economy factors for city and highway driving are presented. Incremental vehicle subsystem changes that account for a fraction of the total energy demand are analyzed to determine individual effects on overall fuel economy. A reverse dynamic optimization methodology is proposed for optimal powertrain integration and control design. A reverse tractive road load demand model developed in Matlab®/Simulink® propagates the required wheel torque and speed derived from vehicle speed and road grade through the powertrain system to determine the required fuel flow for all possible states within the hardware constraints. The control strategy is treated as a multi-stage, multi-dimension decision process, where dynamic programming is applied to find an optimal control policy that minimizes the accumulated fuel flow over a drive cycle. The reverse dynamic optimization methodology and tool are used to assess and develop transmission gear shift, torque converter lock-up clutch, and pedal control strategies that are catered to specific vehicle applications. The reverse model and dynamic optimization technique are extended to virtually optimize variable displacement engine operation taking gear and clutch control interaction effects into account. The reverse model is used for establishing design criteria, such as minimum engine part throttle torque requirements, by determining the required speeds and loads to traverse drive cycles. The advantages of the reverse dynamic optimization approach are demonstrated by performing powertrain matching analyses (i.e., vehicle attribute sensitivity analysis; optimal engine, transmission and axle selection; and variable displacement effects) and key system integration concepts are revealed.Ph.D.Mechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/57640/2/mpapke_1.pd

Transfer of electronic commerce trust between brick-and-mortar and online business environments

Through experimentation, we establish a causal relationship between trust and the expansion of a retailer from online to brick-and-mortar and vice versa. Trust is multidimensional and contingent on the distribution path first chosen. Vendor trustworthiness (knowledge-based) and technological trustworthiness (institution-based) have different effects depending on the initial and new distribution channel. Expanding from brick-and-mortar to online negatively affects technology-based trust, while transfers from an online to a physical location maintain the same level of technology-based trust. Vendor-based trust is positively affected by transfer from online to the brick-and-mortar location, and is not significantly unaffected by transfers from brick and-mortar to online locations. The perceived “permanence” of a physical location influences consumer beliefs about the location’s trustworthiness

DETC2008-50149 DEVELOPMENT OF REVERSE DYNAMIC OPTIMIZATION METHODOLOGY FOR OPTIMAL POWERTRAIN INTEGRATION AND CONTROL DESIGN

ABSTRACT A reverse tractive road load demand model, dynamic optimization methodology, and Matlab®/Simulink® based tool are developed to address the challenge of matching the powertrain hardware and control strategy to specific vehicle attributes and driver applications for improved overall vehicle system efficiency. The reverse dynamic optimization methodology can be used to assess and develop transmission shift and lock-up control strategies, evaluate alternative powertrain hardware configurations, and establish design criteria. The advantages of the reverse dynamic optimization approach are demonstrated and key system integration concepts are revealed by performing vehicle attribute, engine, transmission, and axle sensitivity analyses. MOTIVATION Optimal powertrain integration and control design is essential to developing more fuel efficient vehicles. Vehicle systems are becoming increasingly complex as are drivers expectations for both fuel economy and performance. Shorter product development times result in less time available to evaluate alternative powertrain configurations and control strategies. Often the interrelationship between hardware and control design and their dependence on driver application is overlooked. A reverse tractive road load demand model, dynamic optimization methodology, and Matlab®/Simulink® based tool are proposed to address the challenge of matching the powertrain hardware and control strategy to specific vehicle attributes and driver applications

Self-cleaning and colour-preserving efficiency of photocatalytic concrete: case study of the Jubilee Church in Rome

The Jubilee Church in the south-eastern outskirts of Rome is one of the first buildings constructed with super white reinforced concrete with self-cleaning photocatalytic cement. However, 16 years after the opening of the building, the self-cleaning and colour-preserving properties arising from the titania particles (TiO2) within the concrete mix are not meeting the design requirements and the concrete is showing premature evidence of decay. While the form of the decay is affecting the appearance of the building and not its structural soundness, the ageing pattern of the building's components is resulting in a high maintenance cost, one not easily affordable within the ordinary budget supported by a small parish. This study comprises the first comprehensive step in understanding the causes of the accelerated ageing pattern of the concrete, highlighting methods to improve the long-term durability of the concrete and therefore reduce the cost of its maintenance. Moreover, this research offered the opportunity to test the durability and the effectiveness of the TiO2 in the real conditions on an actual building featuring non-standard geometries. The findings highlight how the ageing pattern directly connects with the geometry of the building and inadequate consideration of the local weathering at the design stage

Environmental barriers to sociality in an obligate eusocial sweat bee

This is the final version of the article. Available from Springer Verlag via the DOI in this record.All data generated or analysed during this study are included in this published article and its supplementary materials.Understanding the ecological and environmental contexts in which eusociality can evolve is fundamental to elucidating its evolutionary origins. A sufficiently long active season is postulated to have been a key factor facilitating the transition to eusociality. Many primitively eusocial species exhibit an annual life cycle, which is thought to preclude the expression of eusociality where the active season is too short to produce successive worker and reproductive broods. However, few studies have attempted to test this idea experimentally. We investigated environmental constraints on the expression of eusociality in the obligate primitively eusocial sweat bee Lasioglossum malachurum, by transplanting nest foundresses from the south to the far north of the United Kingdom, far beyond the natural range of L. malachurum. We show that transplanted bees can exhibit eusociality, but that the short length of the season and harsher environmental conditions could preclude its successful expression. In one year, when foundresses were transplanted only after provisioning first brood (B1) offspring, workers emerged in the north and provisioned a second brood (B2) of reproductives. In another year, when foundresses were transplanted prior to B1 being provisioned, they were just as likely to initiate nesting and provisioned just as many B1 cells as foundresses in the south. However, the life cycle was delayed by approximately 7 weeks and nests suffered 100% B1 mortality. Our results suggest that short season length together with poor weather conditions represent an environmental barrier to the evolution and expression of eusociality in sweat bees.This work formed part of a studentship (1119965) awarded to PJD funded by the Natural Environment Research Council and the University of Sussex, supervised by JF

Helper Response to Experimentally Manipulated Predation Risk in the Cooperatively Breeding Cichlid Neolamprologus pulcher

Background We manipulated predation risk in a field experiment with the cooperatively breeding cichlid Neolamprologus pulcher by releasing no predator, a medium- or a large-sized fish predator inside underwater cages enclosing two to three natural groups. We assessed whether helpers changed their helping behaviour, and whether within-group conflict changed, depending on these treatments, testing three hypotheses: ‘pay-to-stay’ PS, ‘risk avoidance’ RA, or (future) reproductive benefits RB. We also assessed whether helper food intake was reduced under risk, because this might reduce investments in other behaviours to save energy. Methodology/Principal Findings Medium and large helpers fed less under predation risk. Despite this effect helpers invested more in territory defence, but not territory maintenance, under the risk of predation (supporting PS). Experimentally covering only the breeding shelter with sand induced more helper digging under predation risk compared to the control treatment (supporting PS). Aggression towards the introduced predator did not differ between the two predator treatments and increased with group member size and group size (supporting PS and RA). Large helpers increased their help ratio (helping effort/breeder aggression received, ‘punishment’ by the dominant pair in the group) in the predation treatments compared to the control treatment, suggesting they were more willing to PS. Medium helpers did not show such effects. Large helpers also showed a higher submission ratio (submission/ breeder aggression received) in all treatments, compared to the medium helpers (supporting PS). Conclusions/Significance We conclude that predation risk reduces helper food intake, but despite this effect, helpers were more willing to support the breeders, supporting PS. Effects of breeder punishment suggests that PS might be more important for large compared to the medium helpers. Evidence for RA was also detected. Finally, the results were inconsistent with RB

Gut Flora Metabolism of Phosphatidylcholine Promotes Cardiovascular Disease

Metabolomics studies hold promise for the discovery of pathways linked to disease processes. Cardiovascular disease (CVD) represents the leading cause of death and morbidity worldwide. Here we used a metabolomics approach to generate unbiased small-molecule metabolic profiles in plasma that predict risk for CVD. Three metabolites of the dietary lipid phosphatidylcholine—choline, trimethylamine N-oxide (TMAO) and betaine—were identified and then shown to predict risk for CVD in an independent large clinical cohort. Dietary supplementation of mice with choline, TMAO or betaine promoted upregulation of multiple macrophage scavenger receptors linked to atherosclerosis, and supplementation with choline or TMAO promoted atherosclerosis. Studies using germ-free mice confirmed a critical role for dietary choline and gut flora in TMAO production, augmented macrophage cholesterol accumulation and foam cell formation. Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary-choline-enhanced atherosclerosis. Genetic variations controlling expression of flavin monooxygenases, an enzymatic source of TMAO, segregated with atherosclerosis in hyperlipidaemic mice. Discovery of a relationship between gut-flora-dependent metabolism of dietary phosphatidylcholine and CVD pathogenesis provides opportunities for the development of new diagnostic tests and therapeutic approaches for atherosclerotic heart disease