scholarly journals Analytical Method for Calculating Sustainable Airport Capacity

2020 ◽  
Vol 12 (21) ◽  
pp. 9239
Author(s):  
Paola Di Mascio ◽  
Gregorio Rappoli ◽  
Laura Moretti
Keyword(s):  
Federal Aviation Administration ◽  
Calculation Model ◽  
Simulation Software ◽  
Time Interval ◽  
Fast Time ◽  
Safety Issues ◽  
Airport Capacity ◽  
Maximum Delay ◽  
Critical Issues ◽  
Level 3

Capacity is the attitude of an airport to manage a number of operations in a given time interval within a fixed maximum delay (and under given safety conditions). Capacity studies are commonly carried out on five levels of analysis according to the required detail in order to identify the best option that balances economic, logistic and safety issues. This study focuses on level 3 (i.e., analytical methods) developing a calculation model to assess the runway capacity. The model was calibrated by comparing the outputs of different airport configurations with those provided by the circular of the Federal Aviation Administration Airport Capacity and Delay. The model was well calibrated with maximum differences in the analyzed configurations that stood at 1 or 2 movements/hour. The runway capacity of an international airport was calculated and compared to that of the entire airside, assessed through fast time simulation, in a previous study. The analytical model provides runway capacity slightly higher than that of the entire air system, as it cannot evaluate all the critical issues present in the airport that reduce its maximum theoretical capacity. Therefore, depending on the degree of detail required, you can use the developed model or the simulation software; the use of the latter is possible when the airside infrastructure does not adequately support the runway system or in cases of advanced design level.

scholarly journals How the Tower Air Traffic Controller Workload Influences the Capacity in a Complex Three-Runway Airport

2021 ◽  
Vol 18 (6) ◽  
pp. 2807
Author(s):  
Paola Di Mascio ◽  
Riccardo Carrara ◽  
Luca Frasacco ◽  
Eleonora Luciano ◽  
Andrea Ponziani ◽  
...  
Keyword(s):  
Data Collection ◽  
Simulation Software ◽  
Air Traffic ◽  
Fast Time ◽  
Air Traffic Controller ◽  
Air Traffic Controllers ◽  
Airport Capacity ◽  
Time Simulation ◽  
The Impact ◽  
Human Component

Air traffic controllers aim to optimize airport capacity, that is to increase the number of aircraft movements per hour maintaining a limited delay. There are several definitions of capacity, which depend on the considered airport element. This study focused on the development of a method that allows evaluating the impact of tower air traffic controllers’ workload on airport capacity. It adapts a model for the workload of sector controllers designed by Eurocontrol to tower controllers and tests it on a heavily busy international airport. In order to collect controllers’ working times, a campaign of data collection has been carried out from the radio frequency occupation. The results allowed us to extrapolate the hourly percentage of work of the various tower controllers using a fast-time simulation software. By imposing an hourly working threshold on tower air traffic controllers, it was possible to obtain a maximum number of manageable aircraft, which was compared with the airside capacity of the airport. The results show that the maximum traffic manageable from the airside would produce unacceptable workload for tower controllers, highlighting the link between airport capacity and the human component.

The Finite Element Analysis of the Large-Scale Converter Transformer Valve Side of the Electric Field

2013 ◽  
Vol 325-326 ◽  
pp. 476-479 ◽  
Author(s):  
Lin Suo Zeng ◽  
Zhe Wu
Keyword(s):  
Finite Element ◽  
Electric Field ◽  
Large Scale ◽  
Calculation Model ◽  
Simulation Software ◽  
Field Calculation ◽  
Element Analysis ◽  
Ansys Simulation ◽  
The Finite Element Analysis ◽  
Electric Field Calculation

This article is based on finite element theory and use ANSYS simulation software to establish electric field calculation model of converter transformer for a ±800kV and make electric field calculation and analysis for valve winding. Converter transformer valve winding contour distribution of electric field have completed in the AC, DC and polarity reversal voltage.

Evaluation of stability and inactivation methods of SARS-CoV-2 in context of laboratory settings

2020 ◽  
Author(s):  
Sandra Westhaus ◽  
Marek Widera ◽  
Holger F. Rabenau ◽  
Sebastian Hoehl ◽  
Denisa Bojkova ◽  
...  
Keyword(s):  
Culture Media ◽  
Heat Inactivation ◽  
The Novel ◽  
Safety Issues ◽  
Rapid Spread ◽  
Level 3 ◽  
Global Concern ◽  
The Stability ◽  
Novel Coronavirus ◽  
Uv C

SummaryThe novel coronavirus SARS-CoV-2 is the causative agent of the acute respiratory disease COVID-19, which has become a global concern due to its rapid spread. Laboratory work with SARS-CoV-2 in a laboratory setting was rated to biosafety level 3 (BSL-3) biocontainment level. However, certain research applications in particular in molecular biology require incomplete denaturation of the proteins, which might cause safety issues handling contaminated samples. In particular, it is critical to provide proof of inactivation before samples can be removed from the BSL-3.In this study, the stability of the virus in cell culture media at 4°C and on touch panel surfaces used in laboratory environment was analyzed. In addition, we evaluated common lysis buffers that are used in molecular biological laboratories for their ability to inactivate SARS-CoV-2. We have found that guanidine thiocyanate and most of the tested detergent containing lysis buffers were effective in inactivation of SARS-CoV-2, however, the M-PER lysis buffer containing a proprietary detergent failed to inactivate SARS-CoV-2. Furthermore, we compared chemical and non-chemical inactivation methods including ethanol, acetone-methanol mixture, PFA, UV-C light, and heat inactivation.In conclusion, careful evaluation of the used inactivation methods are required and additional inactivation steps are necessary before removal of lysed viral samples from BSL-3.

Mechanical Analysis for Anchorage Zone Connecting Main Cable and Main Girger of Self-Anchored Suspension Bridge

2012 ◽  
Vol 178-181 ◽  
pp. 2281-2284 ◽  
Author(s):  
Qing Tian Su ◽  
Dong Fang Wang
Keyword(s):  
Mechanical Behavior ◽  
Suspension Bridge ◽  
Mechanical Analysis ◽  
Calculation Model ◽  
Refined Model ◽  
Main Cable ◽  
Spatial Beam ◽  
Critical Issues ◽  
Calculation Results ◽  
Main Girder

Self-anchored suspension bridge is a self-balancing system by anchored the main cable at each end of main girder. With complicated configuration and important rule of transferring tension in main cable to main girder, the anchorage region is one of the most critical issues during designing a self-anchored suspension bridge. It is impossible to fully understand the mechanical behavior only by spatial beam and column model but spatial refined model. Because the behavior of anchorage region is greatly influenced by its boundary condition, in this paper, reasonable length of main girder in calculation model is discussed based on the spatial refined model. The mechanical behavior of initial anchorage structure is calculated. A modified anchorage configuration is proposed according to the stresses distribution of anchorage zone. Calculation results show the modified anchorage configuration can make the force transferring smoothly and decrease the stresses of anchorage structure, and it can be referenced to similar bridges.

scholarly journals Analysis of Shunted Screen Gravel Pack Process and Calculation of Friction in Deepwater Horizontal Wells

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Fei Xu ◽  
Shengtian Zhou ◽  
Chong Zhang ◽  
Yi Yu ◽  
Zhao Dong
Keyword(s):  
Pressure Gauge ◽  
Calculation Model ◽  
Simulation Software ◽  
Gas Field ◽  
Carrier Fluid ◽  
Fracture Pressure ◽  
Open Hole ◽  
Packing Process ◽  
Gravel Packing ◽  
Gravel Pack

Shunted screen gravel packing is a kind of technology which is difficult to complete gravel packing with the conventional method in low fracture pressure formation and long wellbore length condition. According to the characteristics of LS 17-2 deepwater gas field, the shunted screen packing tool was designed and the gravel packing process and packing mechanism were analyzed. The variation law of the flow friction, flow rate distribution in multichannel, and other parameters of the shunted screen gravel packing were analyzed and calculated. The friction calculation model of different stages of gravel packing was established. A gravel packing simulation software was developed to simulate the friction in different stages of shunted screen gravel packing. The parameters such as sand-dune ratio, pumping sand amount, packing length, and packing time in the process of packing were also calculated. In deepwater horizontal well gravel packing, the results show that the friction ratio of the string is the largest in the stage of injection and α-wave packing. While the friction increases rapidly in the stage of β-wave packing because the carrier fluid needs to flow through the long and narrow washpipe/screen annulus. Particularly when the β-wave packing is near the beginning of the open hole, the packing pressure reaches the maximum. The calculated results are in good agreement with the measured results of the downhole pressure gauge. The model and software can provide technical support for the prediction and optimization of gravel packing parameters in the future.

scholarly journals Airspace Capacity Assessment with Augmented Cell Transmission Model

2021 ◽  
Author(s):  
Wei Gao ◽  
Man Liang
Keyword(s):  
Air Traffic ◽  
Mixed Integer ◽  
Transmission Model ◽  
Capacity Assessment ◽  
Fast Time ◽  
Cell Transmission Model ◽  
Traffic Demand ◽  
Airport Capacity ◽  
Cell Transmission ◽  
The Impact

Air traffic congestion is caused by the unbalance between increasing traffic demand and saturating capacity. Flight delay not only causes huge economical lost, but also has very negative environmental impact in the whole air transportation system. In order to identify the impact of extended TMA on airport capacity, an airspace capacity assessment method based on augmented cell transmission model was proposed. Firstly, the airspace structure was modeled with points, segments, layers, and cells. Secondly, mixed integer linear programming model was built up with maximum throughput or capacity as the objective function. Finally, genetic algorithm was used to find the optimal result, and the results were validated by comparing with the fast-time simulation results generated by total airspace and airport modeler (TAAM) software. It is found that the proposed method could achieve a relatively accurate result in a much affordable and fast way. The numerical results could be very helpful for air traffic controllers to analyze the dynamic traffic flow entering and exiting TMA, so as to make decisions via reasonable analysis and do planning in advance by referring to the airport capacity.

Establishing simulation model for optimizing efficiency of CNC machine using reliability-centered maintenance approach

2019 ◽  
Vol 10 (06) ◽  
pp. 1950034 ◽  
Author(s):  
Zahid Hussain ◽  
Hamid Jan
Keyword(s):  
Preventive Maintenance ◽  
Simulation Software ◽  
Time Interval ◽  
Total System ◽  
Cnc Machine ◽  
Effect Analysis ◽  
System Cost ◽  
Reliability Centered Maintenance ◽  
Maintenance Time ◽  
Critical Components

The objective of this work was to enhance the product’s quality by concentrating on the machine’s optimized efficiency. In order to increase the machine’s reliability, the basis of reliability-centered maintenance approach was utilized. The purpose was to establish a planned preventive maintenance strategy to identify the machine’s critical components having a noteworthy effect on the product’s quality. The critical components were prioritized using failure mode and effect analysis (FMEA). The goal of the study was to decrease the ppm time interval for a CNC machine by simulating the projected preventive maintenance time interval. For this purpose, the simulation software ProModel 7.5 was implemented for the current preventive maintenance procedure to choose the best ppm time interval which contributed better norms. Five dissimilar optimization approaches were applied, however, the first approach yielded the prominent total system cost and the shorter ppm interval. The results of the study revealed that there was an increase of USD 1878 as a result of an increase in total system cost from USD 78,365 to USD 80,243. Preventive maintenance costs were reduced from USD 4196 to USD 2248 (46%). The costs associated with good parts increased from USD 8259 to USD 8294 (0.4%) and the costs associated with defective parts reduced from USD 171 to USD 3 (98.25%), respectively.

Critical Issues in Global Navigation Satellite Systems

2011 ◽  
pp. 151-157
Author(s):  
Ina Freeman ◽  
Jonathan M. Auld
Keyword(s):  
Atomic Clock ◽  
Global Navigation Satellite Systems ◽  
Time Interval ◽  
Navigation Satellite ◽  
Satellite Systems ◽  
Critical Issues ◽  
Radio Signals ◽  
Global Navigation ◽  
Defense Research ◽  
Global Navigation Satellite

Global Navigation Satellite Systems (GNSS) is a concept that relays accurate information of a position or location anywhere on the globe using a minimum of four satellites, a control station, and a user receiver. GNSS owes its origins to Rabi’s work in the early 1940s with the concept of an atomic clock (Nobel Museum, http://www.nobel.se/physics/laureates/1944/rabi-bio.html). In October 1940, the National Defense Research Council in the U.S. recommended implementing a new navigation system that combined radio signals with this new technology of time interval measurements. From this, MIT developed Long Range Radio Aid to Navigation (LORAN), which was refined by scientists at John Hopkins University and utilized during World War II through the late 1950s.

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