Organophosphate esters (OPEs) are used in aircraft lubricating oil and hydraulic fluids, and, thus, airplane emissions are thought to be an important source of these chemicals in the environment. In ...this study, concentrations of 20 OPEs, comprising seven alkyl-OPEs, three chlorinated (Cl)-OPEs, seven aryl-OPEs, and three oligomeric-OPEs, were determined in outdoor air, soil, pine needles, river water, and outdoor dust samples collected around an airport in Albany, New York, in 2018. Elevated ∑OPE concentrations were found in outdoor air, soil, pine needles, outdoor dust, and river water in the ranges of 1320–20,700 pg/m3 (median: 3880), 1.16–73.1 (14.3) ng/g dry weight (dw), 23.2–534 (102) ng/g (dw), 153–2140 (824) ng/g (dw), and 174–24,600 (1250) ng/L, respectively. The total OPE concentrations in air, soil, water, and outdoor dust samples in the study area were dominated by Cl-OPEs, whereas those in pine needles were dominated by aryl-OPEs. The spatial distribution of OPEs in air, soil, and pine needles showed a gradual decreasing trend with increasing distance from the airport. A significant correlation was observed between ∑OPE concentrations in air and soil, and the fugacity ratio showed the flux of OPEs from air to soil. The spatial distribution of OPEs between air and pine needles was similar and highly correlated, suggesting that pine needles are suitable indicators of atmospheric OPE concentrations. In addition to urban activities, aircraft hydraulic/lubricant oils are a major source of OPEs in the vicinity of the airport. The average daily intake of OPEs via air inhalation and outdoor dust ingestion in the vicinity of the airport was up to 1.53 ng/kg bw/day for children and 0.73 ng/kg bw/day for adults.
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•OPEs are ubiquitous in air, soil, dust, river water and pine needles collected near airports.•The fugacity ratio showed the flux of OPEs from air to soil.•Aircraft oils/hydraulic fluids are a major source of OPEs around airports.•Pine needles reflect spatial gradient in atmospheric OPE concentrations.•Airports are a source of OPEs in the environment.
There is a growing interest in the passenger experience at the airport. Particularly, the relevance of passenger satisfaction has been emphasized. However, although different research approaches have ...been used, there is still a gap related to understanding the several relationships between aspects associated with passenger satisfaction with the airport. In this study, a comprehensive conceptual model, which includes the relationships between key antecedents and consequences of passenger satisfaction, was developed and examined. Using structural equation modeling analysis, several findings concerning passenger expectations, airport service quality, switching costs for changing airports, and passenger loyalty towards the airport are stressed.
•The relationships between the antecedents and consequences of passenger satisfaction with the airport were examined.•A causal model comprised different aspects of the passenger perceptions of the airport as a service experience.•Passenger expectation regarding the airport experience is mostly associated with the idea of a minimum tolerable performance.•Stresses the relevance of the existence of switching costs for passenger loyalty in a multi-airport region.
Analysis of airport stakeholders Schaar, David; Sherry, Lance
2010 Integrated Communications, Navigation, and Surveillance Conference Proceedings
Conference Proceeding
Airports are of significant economic importance to regional businesses and to the quality of life of residents by providing access to safe, secure, rapid, affordable air transportation services. At ...the major U.S. airports, regional airport authorities operate the airports as public utilities providing infrastructure to service providers and their supply chain under "revenue neutral" financial regulations. As public entities with no stockholder profit motives, the airport authorities are obliged to work to balance the interests of all of their stakeholders to build the airport infrastructure, lease space to service providers, and ensure that the service providers collaborate to provide seamless, safe, secure service to the consumers of air travel services. A review of published airport benchmarks revealed that they are largely ambiguous on stakeholders and stakeholder boundaries.
The purpose of this research is to understand how and why warehouses have changed location over time from central urban areas to the urban periphery: spatial decentralization. Over the last decade, ...the logistics industry has been restructured to transport large volumes of goods more quickly and reliably. Concurrently, the warehousing industry experienced changes in facility size and location: large warehouses have been built on the urban outskirts. This spatial shift is attributed to inventory and transport cost trade-offs: the gains from lower land prices and scale operation outweigh the increase in transport costs as warehouses decentralized from central urban areas. As a case study, I examine location choices of 5364 warehousing facilities in Los Angeles, CA. I hypothesize that (a) the location choice varies by facility size and (b) the location choice logic has changed over time. Results suggest significant differences in the effect of location choice factors over facility size and over time. For warehouses built before 1980, the most influential factors are local market, labor, and seaport/intermodal terminal proximity. In contrast, for warehouses built after 2000, lower land price and airport/intermodal terminal proximity have the greatest effects.
•We examine why warehouses over the last decades have changed location.•Location determinants of 5364 warehouses in Los Angeles, CA are examined.•Facility size and built year explain the variation in warehouse location choice.•Newer, larger ones seek lower rent, better airport access, and less market access.•Potential decrease in facility cost is likely; transport cost change yet unclear.
For travellers in the airport, waiting is often associated as an unpleasant activity. One of the reasons of the perception is because waiting area is viewed as a space for uncomfortable waiting ...experience. Bissel explains that the experience of waiting is often conceptualised as a stasis period that bore the passenger to be passive. Regarding to this understanding, Schweizer and Gasparini try to dissect the potential of a waiting space by using active waiting concept as a lens of analysing the space. According to their concept, active waiting is where waiting is seen as an activity that has balance focus between achieving what is expected and how to have comfort when experiencing the process itself. This paper argues, by incorporating this concept to a waiting space, passengers will experience in both passenger system and a new occasional experience. This paper will observe and analyse the relation between spatial elements and the behaviour of passengers at a waiting area within an airport terminal, through the lens of active waiting concept. The experience of waiting can be achieved through three stages of habitation, which is lingering, tarrying, and the state of dwelling. The expected result from this study is to discover the potentials of waiting area at an airport. Findings from this paper may be useful for planning the airport waiting in order to create a more comfortable experience for the body and state of mind of the passengers.
Robustness of the air transport network Lordan, Oriol; Sallan, Jose M.; Simo, Pep ...
Transportation research. Part E, Logistics and transportation review,
08/2014, Letnik:
68
Journal Article
Recenzirano
•This paper defines a methodology to detect critical airports of the air transport network (ATN).•The methodology is based on the effect of airport disconnection on size of giant component.•A list of ...critical airports for the global ATN of November 2011–November 2012 is presented.•A new node selection criterion to disconnect airports presented, based on Bonacich power centrality.•This new criterion is compared to a wide range of node selection criteria present in the literature.
This paper presents a methodology for the detection of critical airports (those whose isolation would cause the largest losses in network connectivity) in the global air transport network (ATN), based on simulating an attack on selected ATN airports using different adaptive selection criteria. The performances of several node selection criteria are compared, together with a new criterion based on Bonacich power centrality. The results show that most critical airports can be detected with an adaptive strategy based on betweenness centrality. The detection of such airports may help the development of contingency plans to develop an appropriate response to any airport closure.
•The appliances energy consumption prediction in a low energy house has been studied.•Weather data from a nearby station was found to improve the prediction.•Pressure, air temperature and wind speed ...are important parameters in the prediction.•Data from a WSN that measures temperature and humidity increase the pred. accuracy.•From the WSN, the kitchen, laundry and living room data ranked high in importance.
This paper presents and discusses data-driven predictive models for the energy use of appliances. Data used include measurements of temperature and humidity sensors from a wireless network, weather from a nearby airport station and recorded energy use of lighting fixtures. The paper discusses data filtering to remove non-predictive parameters and feature ranking. Four statistical models were trained with repeated cross validation and evaluated in a testing set: (a) multiple linear regression, (b) support vector machine with radial kernel, (c) random forest and (d) gradient boosting machines (GBM). The best model (GBM) was able to explain 97% of the variance (R2) in the training set and with 57% in the testing set when using all the predictors. From the wireless network, the data from the kitchen, laundry and living room were ranked the highest in importance for the energy prediction. The prediction models with only the weather data, selected the atmospheric pressure (which is correlated to wind speed) as the most relevant weather data variable in the prediction. Therefore, atmospheric pressure may be important to include in energy prediction models and for building performance modeling.
Turkey’s airport industry has experienced substantial growth over the recent years, but few studies have analysed their operational efficiency. This paper uses Malmquist productivity index (classical ...and bootstrapping) to assess the operational performance of 21 Turkey airports during the period of 2009 through 2014. The findings indicated that the efficiency and productivity of the majority of the Turkish airports increased during the period under investigation. However, in the period of 2011–2012, a significant decline was observed in efficiency. The main reason of this stagnation is the significant increase in the physical capacity of the Turkish airports in 2011. The non-reflection of the increasing physical capacity to passenger and cargo traffic caused a decline in 2012. In spite of declining in the period of 2011–2012, efficiency values of Turkish airports have increased again since 2013. Moreover, decomposition of the Malmquist index showed that most Turkey airports experienced losses in efficiency; however, in terms of technology, they have progressed. Two significant factors (i.e. operating hours and percentage of international traffic) were identified by the Simar-Wilson double bootstrapping regression analysis as explaining variations in airport efficiency.
•Airport performance evaluations are very important for the development of a country.•Turkey’s airport industry has experienced substantial growth over the recent years.•This study evaluates Turkish airports comparative efficiencies for 2009-2014 period.•Productivity of the majority of the Turkish airports increased during the related period.•In the period of 2011-2012, a significant decline was observed in efficiency.
Since its inception in 1955, when Delta Airlines pioneered the hub-and-spoke system at their Atlanta hub, airports have been engaged in fierce competition to ensure efficient and dependable transfers ...for passengers and airlines between connecting flights. In line with this overarching objective, we present a long-term layout design problem that focuses on optimizing the placement of moving walkways within the corridors of an airport terminal. Our primary goal is to facilitate faster transfers on these walkways, thereby improving gate connectivity. To achieve this, we propose the following budget-constrained optimization task: Maximize the weighted number of gate pairs that passengers can transfer between, without exceeding the specified minimum connecting time for each gate pair. We mathematically formulate the resulting optimization problem and provide a comprehensive analysis of its computational complexity. Additionally, we introduce suitable solution methods to tackle this challenging optimization task. Through a comprehensive computational study, using real-world terminal data, we evaluate the performance of our solution approaches. Our results demonstrate that optimized walkway layouts significantly contribute to reliable connecting processes during daily airport operations.
•We optimize the placement of moving walkways in airport terminals.•We formulate a novel optimization problem and analyze its complexity.•Novel optimization methods to solve the problem are provided.•Real-world terminal data is applied to show improved gate connectivity.
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