Simulation Modeling and Analysis of Complex Port Operations with Multimodal Transportation

AbstractWorld trade has been increasing dramatically in the past two decades, and as a result containers exchange has grown significantly. Accordingly, container terminals are expanding to meet this increase and new container ports have opened. Ports with one or more container terminals are considered complex systems in which many resources, entities and transporters interact to achieve the objective of safely moving containers delivered by ships inland as well as loading containers delivered by trucks and rail onto ships. Ports with multimodal transportation systems are in particular complex as they typically operate with ships arriving to one or more terminals, multiple quay cranes, rubber tyred gantry cranes, trains, and trucks delivering containers of different types to terminals.With several resources of different types working and interacting, the system can be so complex that it is not easy to predict the behavior of the system and its performance metrics without the use of simulation. In this paper, a generic discrete-event simulation that models port operations with different resource types including security gates, space, rubber tyred gantry cranes, trains, quay cranes, and arriving and departing ships, trucks, and trains is presented. The analysis will entail studying various scenarios motivated by changes in different inputs to measure their impact on the outputs that include throughput, resource utilization and waiting times

Economics of Household Solar Panel and Wind Turbine Systems

Small wind turbines and photovoltaic (PV) technologies are available for purchase and use to provide households with electricity. The objective of this research is to determine the economic consequences of installing microgeneration grid-tied wind turbine systems (6 kW; 10 kW) and solar panel systems (4 kW; 12 kW), given alternative pricing structures for households, at five locations with different wind speed and solar radiation resources. Twenty years of hourly wind speed, solar radiation, and temperature data, and hourly electricity use data for representative households, were obtained for each location. Weather data, electricity pricing rate schedules, and purchase prices and power output response functions for each wind turbine and solar panel system are used to address the objective. The estimated annual cost of $2,148 for the least costly household grid-tied 4 kW solar panel system with net metering is two-times greater than the annual cost of purchasing from the grid. If external consequences of electricity generation and distribution are ignored, given region specific rate structures and prices, household solar panel electricity generation systems are not economically competitive in the region studied. The economic consequences of grid-tied household wind turbine and solar panel systems differ substantially among locations. Additionally, the consequences of a carbon tax, equal to an estimated social cost of carbon of$37.2/Mg, on household electricity cost is determined. Averaged across the five households, the carbon tax is expected to reduce annual consumption by 4.4% for traditional meter households and by 4.9% for households charged smart meter rates. The carbon tax increases electricity cost by 19%. For a household cost of $202/year the carbon tax is expected to reduce social costs by$11. Annual carbon tax collections of $234/household are expected. Adding the carbon tax was found to be insufficient to incentivize households to install either a solar panel or wind turbine system. Installation of a 4 kW solar system would increase the annual cost by$1,546 and decrease CO2 emissions by 38% valued at $94/household. The consequence of a carbon tax would depend largely on how the proceeds of the tax are used.Agricultural Economic

Human Direct Skin Feeding Versus Membrane Feeding to Assess the Mosquitocidal Efficacy of High-Dose Ivermectin (IVERMAL Trial)

Item does not contain fulltex

Population Pharmacokinetics of Liposomal Amphotericin B in Immunocompromised Children

BACKGROUND Liposomal amphotericin B (LAmB) is widely used in the treatment of invasive fungal disease (IFD) in adults and children. There are relatively limited PK data to inform optimal dosing in children that achieves systemic drug exposures comparable to those of adults. OBJECTIVES To describe the pharmacokinetics of LAmB in children aged 1-17 years with suspected or documented IFD. METHODS Thirty-five children were treated with LAmB at dosages of 2.5-10 mg kg(-1) daily. Samples were taken at baseline and at 0.5-2.0 hourly intervals for twenty-four hours after receipt of the first dose (n=35 patients) and on the final day of therapy (n=25 patients). LAmB was measured using high performance liquid chromatography (HPLC). The relationship between drug exposure and development of toxicity was explored. RESULTS An evolution in PK was observed during the course of therapy resulting in a proportion of patients (n=13) having significantly higher maximum serum concentration (Cmax) and area under the concentration time curve (AUC0-24) later in the course of therapy, without evidence of drug accumulation (Cmin accumulation ratio, AR < 1.2). The fit of a 2-compartment model incorporating weight and an exponential decay function describing volume of distribution best described the data. There was a statistically significant relationship between mean AUC0-24 and probability of nephrotoxicity (OR 2.37; 95% CI 1.84-3.22, p=0.004). CONCLUSIONS LAmB exhibits nonlinear pharmacokinetics. A third of children appear to experience a time-dependent change in PK, which is not explained by weight, maturation or observed clinical factors

Undulator design for Laser Plasma Based Free electron laser

The fourth generation of synchrotron radiation sources, commonly referred to as the Free Electron Laser (FEL), provides an intense source of brilliant X-ray beams enabling the investigation of matter at the atomic scale with unprecedented time resolution. These sources require the use of conventional linear accelerators providing high electron beam performance. The achievement of chirped pulse amplification allowing lasers to be operated at the Terawatt range, opened the way for the Laser Plasma Acceleration (LPA) technique where high energy electron bunches with high current can be produced within a very short centimeter-scale distance. Such an advanced acceleration concept is of great interest to be qualified by an FEL application for compact X-ray light sources. We explore in this paper what the LPA specificities imply on the design of the undulator, part of the gain medium. First, the LPA concept and state-of-art are presented showing the different operation regimes and what electron beam parameters are likely to be achieved. The LPA scaling laws are discussed afterwards to better understand what laser or plasma parameters have to be adjusted in order to improve electron beam quality. The FEL is secondly discussed starting with the spontaneous emission, followed by the different FEL configurations, the electron beam transport to the undulator and finally the scaling laws and correction terms in the high gain case. Then, the different types of compact undulators that can be implemented for an LPA based FEL application are analyzed. Finally, examples of relevant experiments are reported by describing the transport beamline, presenting the spontaneous emission characteristics achieved so far and the future prospects

SARS-CoV-2 viability on sports equipment is limited, and dependent on material composition

OBJECTIVES The control of the COVID-19 pandemic in the UK has necessitated restrictions on amateur and professional sports due to the perceived infection risk to competitors, via direct person to person transmission, or possibly via the surfaces of sports equipment. The sharing of sports equipment such as tennis balls was therefore banned by some sport’s governing bodies. We sought to investigate the potential of sporting equipment as transmission vectors of SARS-CoV-2. Methods Ten different types of sporting equipment, including balls from common sports, were inoculated with 40μl droplets containing clinically relevant concentrations of live SARS-CoV-2 virus. Materials were then swabbed at time points relevant to sports (1, 5, 15, 30, 90 minutes). The amount of live SARS-CoV-2 recovered at each time point was enumerated using viral plaque assays, and viral decay and half-life was estimated through fitting linear models to log transformed data from each material. RESULTS At one minute, SARS-CoV-2 virus was recovered in only seven of the ten types of equipment with the low dose inoculum, one at five minutes and none at 15 minutes. Retrievable virus dropped significantly for all materials tested using the high dose inoculum with mean recovery of virus falling to 0.74% at 1 minute, 0.39% at 15 minutes and 0.003% at 90 minutes. Viral recovery, predicted decay, and half-life varied between materials with porous surfaces limiting virus transmission. CONCLUSIONS This study shows that there is an exponential reduction in SARS-CoV-2 recoverable from a range of sports equipment after a short time period, and virus is less transferrable from materials such as a tennis ball, red cricket ball and cricket glove. Given this rapid loss of viral load and the fact that transmission requires a significant inoculum to be transferred from equipment to the mucous membranes of another individual it seems unlikely that sports equipment is a major cause for transmission of SARS-CoV-2. These findings have important policy implications in the context of the pandemic and may promote other infection control measures in sports to reduce the risk of SARS-CoV-2 transmission and urge sports equipment manufacturers to identify surfaces that may or may not be likely to retain transferable virus