Minimizing the Cost of Innovative Nuclear Technology Through Flexibility: The Case of a Demonstration Accelerator-Driven Subcritical Reactor Park

Presented is a methodology to analyze the expected Levelised Cost Of Electricity (LCOE) in the face of technology uncertainty for Accelerator-Driven Subcritical Reactors (ADSRs). It shows that flexibility in the design and deployment strategy of an ADSR park demonstrator significantly reduces its expected LCOE. The methodology recognizes in the conceptual design a range of possible technological outcomes for the ADSR accelerator system. It identifies flexibility “on” and “in” the design to modify the future development path in light of such uncertain scenarios. Uncertainty and flexibility are incorporated in the ADSR valuation. The resulting economic assessment is more realistic than typical discounted cash flow analysis that does not consider a range of development outcomes, or the flexibility to change development path

Impact of Heavy Aircraft Operations on Airport Capacity at Newark Liberty International Airport

Aviation System Performance Metrics (ASPM) departure and arrival rate data is collected for four common airport confi gurations at Newark Liberty International Airport (EWR) under Visual Meteorological Conditions (VMC) for the period 2007-2008. The effect of the number of Heavy (including Boeing 757) operations on overall airport throughput is then investigated. The investigation shows that Heavy departures and arrivals negatively impact overall airport capacity. Mechanisms by which controllers mitigate the e ffects of Heavy arrivals and departures are also identifi ed. A preliminary quanti fication of the impact of operations of Heavy aircraft is performed with a parametric estimation of the capacity of the airport. The findings of this empirical study highlight that Heavy aircraft departures introduce a very small effi ciency loss in terms of airport departure capacity. By contrast, under some runway con figurations, Heavy aircraft arrivals have a more detrimental e ffect on airport departure capacity

Mitochondria Are Related to Synaptic Pathology in Alzheimer's Disease

Morphological alterations of mitochondria may play an important role in the pathogenesis of Alzheimer's disease, been associated with oxidative stress and Aβ-peptide-induced toxicity. We proceeded to estimation of mitochondria on electron micrographs of autopsy specimens of Alzheimer's disease. We found substantial morphological and morphometric changes of the mitochondria in the neurons of the hippocampus, the neocortex, the cerebellar cortex, the thalamus, the globus pallidus, the red nucleus, the locus coeruleus, and the climbing fibers. The alterations consisted of considerable changes of the cristae, accumulation of osmiophilic material, and modification of the shape and size. Mitochondrial alterations were prominent in neurons, which showed a depletion of dendritic spines and loss of dendritic branches. Mitochondrial alterations are not related with the accumulation of amyloid deposits, but are prominent whenever fragmentation of the Golgi apparatus exists. Morphometric analysis showed also that mitochondria are significantly reduced in neurons, which demonstrated synaptic pathology

Designing Efficient Taxi Pickup Operations at Airports

This paper provides a practical procedure for designing efficient taxi pickup operations at airports. How to do this effectively is an open question. Solutions are not available, and practices vary. They reflect different approaches to and lack of research on the subject. The solutions are often unsatisfactory. At many airports, passengers routinely suffer long waits outdoors, exposed to the elements, after a tiring journey. Such disagreeable experiences are avoidable. Designing efficient taxi pickup operations at airports is problematic. The peculiarities of the process preclude easy solutions. First, the process involves queuing, so system performance is a nonlinear function of the loads. Second, it features unstable transient situations, since travelers typically arrive in bulk over short periods. Third, traffic is significantly differentiated and consists of a wide variety of groups implying different service characteristics. Standard results from queuing theory thus do not have a useful application to this problem. The design process uses simulation that is based on detailed observation of local practices. It involves four steps: (a) detailed local measurements of the arrival of both travelers and taxis, and the service rates provided by taxis in different queuing positions; (b) creation and validation of a simulation model sufficiently detailed to account for these realities; (c) exploration of design alternatives to estimate the characteristics of the service they would provide; and (d) selection of a preferred design that properly balances efforts to minimize average and extreme wait times. The paper demonstrates the procedure through application to Lisbon International Airport, Portugal.SIMUL8 Corporatio

Patterns of geohelminth infection, impact of albendazole treatment and re-infection after treatment in schoolchildren from rural KwaZulu-Natal/South-Africa

BACKGROUND: Geohelminth infection is a major health problem of children from rural areas of developing countries. In an attempt to reduce this burden, the Department of Health of the province of KwaZulu-Natal (KZN) established in 1998 a programme for helminth control that aimed at regularly treating primary school children for schistosomiasis and intestinal helminths. This article describes the baseline situation and the effect of treatment on geohelminth infection in a rural part of the province. METHODS: Grade 3 schoolchildren from Maputaland in northern KZN were examined for infections with hookworm, Ascaris lumbricoides, and Trichuris trichiura, treated twice with 400 mg albendazole and re-examined several times over one year after the first treatment in order to assess the impact of treatment and patterns of infection and re-infection. RESULTS: The hookworm prevalence in the study population (83.2%) was considerably higher than in other parts of the province whereas T. trichiura and especially A. lumbricoides prevalences (57.2 and 19.4%, respectively) were much lower than elsewhere on the KZN coastal plain. Single dose treatment with albendazole was very effective against hookworm and A. lumbricoides with cure rates (CR) of 78.8 and 96.4% and egg reduction rates (ERR) of 93.2 and 97.7%, respectively. It was exceptionally ineffective against T. trichiura (CR = 12.7%, ERR = 24.8%). Re-infection with hookworm and A. lumbricoides over 29 weeks after treatment was considerable but still well below pre-treatment levels. CONCLUSION: High geohelminth prevalences and re-infection rates in the study population confirm the need for regular treatment of primary school children in the area. The low effectiveness of single course albendazole treatment against T. trichiura infection however demands consideration of alternative treatment approaches

An Airport Experience Framework from a Tourism Perspective

This study, by integrating the perspectives of sociological, psychological, and service marketing and management, all of which affect the passenger experience, proposes a theoretical framework for the creation of the airport experience in relation to tourism. This research responds to the current phenomenon in which airports are offering other types of experiences within the airport terminal, expanding the role of an airport from being a utility for transportation into a place where various and different values can be offered. This research explores the current airport experience and adds to research on airport experience by clarifying ten key components necessary for airport passenger experience propositions based on existing research, the current industry phenomena, and the empirical study. The paper also underlines those components that can enhance passenger experience in relation to tourism and highlights the role that airports contribute to a destination

Feedback Control of the National Airspace System

This paper proposes a general modeling framework adapted to the feedback control of traffic flows in Eulerian models of the National Airspace System. It is shown that the problems of scheduling and routing aircraft flows in the National Airspace System can be posed as the control of a network of queues with load-dependent service rates. Focus can then shift to developing techniques to ensure that the aircraft queues in each airspace sector, which are an indicator of the air traffic controller workloads, are kept small. This paper uses the proposed framework to develop control laws that help prepare the National Airspace System for fast recovery from a weather event, given a probabilistic forecast of capacities. In particular, the model includes the management of airport arrivals and departures subject to runway capacity constraints, which are highly sensitive to weather disruptions.National Science Foundation (U.S.) (Contract ECCS-0745237)United States. National Aeronautics and Space Administration (Contract NNA06CN24A

Toward evaluating the effect of climate change on investments in the water resources sector: insights from the forecast and analysis of hydrological indicators in developing countries

The World Bank has recently developed a method to evaluate the effects of climate change on six hydrological indicators across 8951 basins of the world. The indicators are designed for decision-makers and stakeholders to consider climate risk when planning water resources and related infrastructure investments. Analysis of these hydrological indicators shows that, on average, mean annual runoff will decline in southern Europe; most of Africa; and in southern North America and most of Central and South America. Mean reference crop water deficit, on the other hand, combines temperature and precipitation and is anticipated to increase in nearly all locations globally due to rising global temperatures, with the most dramatic increases projected to occur in southern Europe, southeastern Asia, and parts of South America. These results suggest overall guidance on which regions to focus water infrastructure solutions that could address future runoff flow uncertainty. Most important, we find that uncertainty in projections of mean annual runoff and high runoff events is higher in poorer countries, and increases over time. Uncertainty increases over time for all income categories, but basins in the lower and lower-middle income categories are forecast to experience dramatically higher increases in uncertainty relative to those in the upper-middle and upper income categories. The enhanced understanding of the uncertainty of climate projections for the water sector that this work provides strongly support the adoption of rigorous approaches to infrastructure design under uncertainty, as well as design that incorporates a high degree of flexibility, in response to both risk of damage and opportunity to exploit water supply 'windfalls' that might result, but would require smart infrastructure investments to manage to the greatest benefit