Geography and the cruise ship port selection process

The cruise ship industry is currently undergoing a period of rapid expansion. New cruise capacity threatens to produce overtonnaging, with future berths exceeding demand. Despite this development, cruise operators are confident that a growing North American market will be able to satisfy the equilibrium condition sought by vessel operators. This research explores where the new tonnage might be deployed and its eventual impact on the cruise industry. Geographic concepts are utilized to test and support the premise that geography contributes positively to the cruise port selection process. Itineraries, influenced by ‘site’ and ‘situation,’ are presently still the most important factor affecting cruise port selection.     

Increase in particle number emissions from motor vehicles due to interruption of steady traffic flow

We assess the increase in particle number emissions from motor vehicles driving at steady speed when forced to stop and accelerate from rest. Considering the example of a signalized pedestrian crossing on a two-way single-lane urban road, we use a complex line source method to calculate the total emissions produced by a specific number and mix of light petrol cars and diesel passenger buses and show that the total emissions during a red light is significantly higher than during the time when the light remains green. Replacing two cars with one bus increased the emissions by over an order of magnitude.     

Combustion instabilities and nanoparticles emission fluctuations in GDI spark ignition engine

The main challenge facing the concept of gasoline direct injection is the unfavourable physical conditions at which the premixed charge is prepared and burned. These conditions include the short time available for gasoline to be sprayed, evaporated, and homogeneously mixed with air. These conditions most probably affect the combustion process and the cycle-by-cycle variation and may be reflected in overall engine operation. The aim of this research is to analyze the combustion characteristics and cycle-by-cycle variation including engine-out nanoparticulates of a turbocharged, gasoline direct injected spark ignition (DISI) engine at a wide range of operating conditions. Gasoline DISI, turbo-intercooled, 1.6L, 4 cylinder engine has been used in the study. In-cylinder pressure has been measured using spark plug mounted piezoelectric transducer along with a PC based data acquisition. A single zone heat release model has been used to analyze the in-cylinder pressure data. The analysis of the combustion characteristics includes the flame development (0–10% burned mass fraction) and rapid burn (10–90% burned mass fraction) durations at different engine conditions. The cycle-by-cycle variations have been characterized by the coefficient of variations (COV) in the peak cylinder pressure, the indicated mean effective pressure (IMEP), burn durations, and particle number density. The combustion characteristics and cyclic variability of the DISI engine are compared with data from throttle body injected (TBI) engine and conclusions are developed.     

Practical safety considerations for short headway automated transit systems

Continued interest in Personal Rapid Transit (PRT) systems as one solution to urban traffic congestion emphasizes the need for careful consideration of the safety of short headway automated transit systems. Current approaches to the determination of safe headways are reviewed. The reduction in headway which could be achieved by improved braking and signaling hardware is outlined. Improved design of emergency brakes is the most important single factor in the reduction of safe headways.

Very short headway systems are reviewed from a safety standpoint. Such systems might be safely operated if operation at intermediate headways (separations on the order of the stopping distance) can be avoided.     

Climate Variability and Estuarine Water Resources: A Case Study from Tampa Bay,Florida

Natural variability in the myriad of physical processes that impact and control estuaries occurs at time scales that typically may exceed or partly exceed many monitoring programs. With respect to documenting and monitoring impacts of human influences- on estuaries, it is therefore important to frame the results of short-term monitoring programs within the context of longer term natural variability in the environment. In the Tampa Bay, Florida area, climate variability strongly influences seasonal precipitation, stream flow, and salinity. In particular, El Niño-Southern Oscillation impacts during the winter have the potential to influence both the availability of surface water for water supply withdrawal and the evaluation of the impacts of surface water withdrawals on the ecosystem.     

Morphology and oxidation kinetics of CI engine’s biodiesel particulate matters on cordierite Diesel Particulate Filters using TGA

The impact of small compression ignition (CI) engine operation conditions and fuel properties on diesel and biodiesel particulate matters (PMs) quantity using opacity smoke meter is investigated. The biodiesel engine’s PMs are around a half of diesel engine PMs under the same engine operation conditions. Morphology of both engine’s PMs are also studied using a Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and image processing method. The average primary nanoparticle sizes of diesel and biodiesel engine’s PMs are approximately 34 nm and 32 nm, respectively. The result shows that engine operation condition and fuel property are strongly impact on the quantity and size distribution of primary nanoparticles emission. PM oxidation kinetics on conventional cordierite Diesel Particulate Filters (DPFs) powders by Thermo-gravimetric analysis (TGA) is also successfully studied. The calculated apparent activation energies of biodiesel engine’s PM oxidation on conventional cordierite DPFs powders are lower than that of diesel engine’s PM and carbon black because of unburned oxygenated molecule. The calculated apparent activation energy of biodiesel engine’s PM and diesel engine’s PM oxidize on conventional cordierite DPFs powders with pure air are in the range of 109 ~ 131 kJ/mole and 117 ~ 130 kJ/mole, respectively. It might be expected that smaller primary nanoparticle size of biodiesel engine’s PMs and bio-oxygenate unburned hydrocarbon can promote more PM oxidation rate during vehicle’s DPF regeneration process.     

信息化条件下炮兵火力最优分配问题研究

文章从信息化条件下对炮兵作战的精确性要求出发,针对当前炮兵火力分配面临的困难,分析了对炮兵火力分配影响的因素,建立了炮兵火力最优分配模型。     

Powertrain system optimization for a heavy-duty hybrid electric bus

This research concerns the design of a powertrain system for a plug-in parallel diesel hybrid electric bus equipped with a continuously variable transmission (CVT) and presents a new design paradigm for the plug-in hybrid electric bus (HEB). The criteria and method for selecting and sizing powertrain components equipped in the plug-in HEB are presented. The plug-in HEB is designed to overcome the vulnerable limitations of driving range and performance of a purely electric vehicle (EV), and it is also designed to improve the fuel economy and exhaust emissions of conventional buses and conventional HEBs. Optimization of the control strategy for the complicated and interconnected propulsion system in the plug-in parallel HEB is one of the most significant factors for achieving higher fuel economy and lower exhaust emissions in the hybrid electric vehicle (HEV). In this research, the proposed control strategy was simulated to prove its validity using the ADVISOR (advanced vehicle simulator) analysis simulation tool.