scholarly journals Dynamic properties of a sporadic sodium layer revealed by observations over Zhongshan, Antarctica: A case study

Author(s):  
Xiangcai Chen ◽  
Wentao Huang ◽  
Chao Ban ◽  
Michael J. Kosch ◽  
Damian J. Murphy ◽  
...  
2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110355
Author(s):  
Tomas Eglynas ◽  
Sergej Jakovlev ◽  
Valdas Jankunas ◽  
Rimantas Didziokas ◽  
Jolanta Januteniene ◽  
...  

Introduction: In the paper, we examine the energy consumption efficiency of specialized container diesel trucks engaged in container transportation at a seaport terminal. Objectives: Using the container terminal at Klaipėda in Lithuania as the background for the research, we produced an improved energy consumption model for measuring the theoretical energy consumption and regeneration of diesel trucks at the terminal and provide a comparative analysis. Methods: We created a mathematical model which describes the instantaneous energy consumption of the diesel trucks, taking into account their dynamic properties and the overall geometry of their routes—“Ship-Truck-Stack-Ship”—using the superposition principle. We investigated other critical parameters relevant to the model and provide a statistical evaluation of the transportation process using data from a case study of Klaipėda port, where we collected measurements of container transportation parameters using georeferenced movement detection and logs from wireless equipment positioned on the diesel-powered container trucks. Results: The modeling results showed that an instantaneous evaluation of energy consumption can reveal areas in the container transportation process which have the highest energy loss and require the introduction of new management and process control initiatives to address the regulations which are designed to decrease harmful industrial emissions and encourage novel technologies and thereby increase the eco-friendliness of existing systems. Conclusion: Based on the research results, the article can provide a reference for the estimation of diesel truck efficiency in seaport terminal operations.


2014 ◽  
Author(s):  
C.J.. J. Segnini ◽  
M.. Rashwan ◽  
M.J.. J. Hernandez ◽  
J. A. Rojas ◽  
M.A.. A. Infante

Abstract This paper presents a methodology for the probabilistic analysis of an infill or step-out opportunity using numerical simulation. Sensitivity and uncertainty analyses for all involved parameters were evaluated through different experimental design techniques. Subsequently, a proxy model was established to reproduce the numerical model performance. Finally, three appropriate solutions were selected from a large population of realizations corresponding to probabilistic percentiles (90%, 50%, and 10% certainty that the specified volume will be recovered). This proposed methodology helped the asset team to evaluate the well candidates more precisely, confidently, and in less time than the current standard methodology. More knowledge about the variables and their effects on overall outcomes was also gained, which helped the team make more-informed decisions. The workflow used the same numerical modeling software, incorporating and facilitating the changes of both static and dynamic properties simultaneously. A case study from Teak field, on the east coast of Trinidad, illustrates the applicability of the methodology and compares its results to those obtained using the standard workflow for the asset. The methodology is one of the latest developments in reservoir simulation, and it has not yet been incorporated into the operator's common practices and procedures for exploitation of the TSP fields.


2019 ◽  
Vol 13 (3) ◽  
pp. 517-539 ◽  
Author(s):  
María Cecilia Chiappini ◽  
Kris Scheerlinck ◽  
Yves Schoonjans

Purpose The purpose of this paper is to investigate ways of practicing political power in public space in the interaction between central and marginal users in Glòries, an area under transformation in Barcelona. Originally conceived as the core of its extension, Glòries is now a battle field where conflictive spatial-social manifestations are strongly linked to pending conditions and partially implemented infrastructural projects. The key actors are in large majority illegal migrants, which activities and spatial strategies are particularly uncomfortable for city administrators; challenging the traditional focus on actors that are stable and institutionalized, included and previewed by the tools for urban projects implementation. Design/methodology/approach To achieve insights on urban spatial articulations of appropriations by marginal actors around infrastructures, the method deployed is to look closely at the interplays between persecuted and persecutors and their ways of practicing power in space in the frame of the illegal street markets in Glòries. This is part of an ongoing PhD research on the complexity of involved processes. The research is executed in diverse work packages: mapping of material transformations (morphology, domain, accessibility and permeability), in diverse timeframes; surrounding functions and temporal fixities, appropriations catalysts; media presences and discussions; crossed references with immersive field work and exchange with locals. Findings A broad variety of illegal street markets have been monitored in Glòries, revealing an increase in scale, frequency and levels of tension. Around them, their dynamic properties can be extracted and measured: spatial configurations, sizes, timeframes, number of traders/visitors, the relation to other elements, the strategies of displaying, displacing and dispersing used by the police. In all, the relationship with the infrastructural elements shows crucial and a better understanding of their relations constitutes a path to understand how both infrastructures and collective behavior contribute to dynamic productive and power logics in space. Originality/value This research and case study are an outstanding framework to explore the concrete spatial interactions and interplays of different power or territorialization processes, i.e. the strategies to denote presence and agency – in novel ways. Focusing on their spatial outcomes in contemporary transformation processes where infrastructures are dominant components is a way to inform the design, practice and implementation of city project and management.


2015 ◽  
Vol 67 (1) ◽  
Author(s):  
Sumanta Sarkhel ◽  
John D Mathews ◽  
Shikha Raizada ◽  
Ramanathan Sekar ◽  
Dibyendu Chakrabarty ◽  
...  

2019 ◽  
Vol 8 (12) ◽  
pp. 566
Author(s):  
Yi Huang ◽  
May Yuan ◽  
Yehua Sheng ◽  
Xiangqiang Min ◽  
Yuwei Cao

Traditional Geographic Information Systems (GIS) represent the environment under reductionist thinking, which disaggregates a geographic environment into independent geographic themes. The reductionist approach makes the spatiotemporal characteristics of geo-features explicit, but neglects the holistic nature of the environment, such as the hierarchical structure and interactions among environmental elements. To fill this gap, we integrate the concept geographic scenario with the fundamental principles of General System Theory to realize the environmental complexity in GIS. With the integration, a geographic scenario constitutes a hierarchy of spatiotemporal frameworks for organizing environmental elements and subserving the exploration of their relationships. Furthermore, we propose geo-characterization with ontological commitments to both static and dynamic properties of a geographic scenario and prescribe spatial, temporal, semantic, interactive, and causal relationships among environmental elements. We have tested the utility of the proposed representation in OWL and the associated reasoning process in Semantic Web Rule Language (SWRL) rules in a case study in Nanjing, China. The case study represents Nanjing and the Nanjing presidential palace to demonstrate the connections among environmental elements in different scenarios and the support for information queries, evolution process simulation, and semantic inferences. The proposed representation encodes geographic knowledge of the environment, makes the interactions among environmental elements explicit, supports geographic process simulation, opens opportunities for deep knowledge mining, and grounds a foundation for GeoAI to discover geographic complexity and dynamics beyond the support of conventional theme-centric inquiries in GIS.


2017 ◽  
Vol 27 (11) ◽  
pp. 1750166 ◽  
Author(s):  
Ladislav Pust ◽  
Ludek Pesek

This paper employs a new analytical approach to model the influence of aerodynamic excitation on the dynamics of a bladed cascade at the flutter state. The flutter is an aero-elastic phenomenon that is linked to the interaction of the flow and the traveling deformation wave in the cascade when only the damping of the cascade changes. As a case study the dynamic properties of the five-blade-bunch excited by the running harmonic external forces and aerodynamic self-excited forces are investigated. This blade-bunch is linked in the shroud by means of the viscous-elastic damping elements. The external running excitation depends on the ratio of stator and rotor blade numbers and corresponds to the real type of excitation in the steam turbine. The aerodynamic self-excited forces are modeled by two types of Van der Pol nonlinear models. The influence of the interaction of both types of self-excitation with the external running excitation is investigated on the response curves.


2019 ◽  
Vol 299 ◽  
pp. 01009
Author(s):  
Karim Abbas ◽  
Laura Thurn ◽  
Julia Kessler ◽  
Fabian Eichler

This scientific research deals with lattice structures manufactured with laser powder bed fusion. Laser powder bed fusion is part of additive manufacturing. The so called layered construction is an increasingly used innovative manufacturing process that can be used to realize new design possibilities. Lightweight structures or bionic structures play a key role here. The focus of this work is on periodic lattice structures. In addition to saving resources and reducing the weight of components, lattice structures have particularly pronounced mechanical properties. However, little is known about their thermo- and fluid-dynamic properties. This work describes the first influencing factors of lattice structures ina thermo- and fluid-dynamic context using a case study. The aim of this paper is to evaluate important design and simulation criteria of lattice structures. Different lattice structures are considered, whose strut geometry is varied. The case study is carried out using a heat exchanger. While classical heat exchangers have lamellar structures, the substitution of these by lattice structures is evaluated. Thiswork represents a first consideration of the most important parameters and gives an overview of the most important core points.


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