Investigating traffic-related PM exposure on and under pedestrian bridges: A case study in Xi'an, China

2018 ◽  
Vol 9 (5) ◽  
pp. 877-886 ◽  
Author(s):  
Zhaowen Qiu ◽  
Jianhua Song ◽  
Caihong Hao ◽  
Xiaoxia Li ◽  
H. Oliver Gao
Keyword(s):  
Pedestrian Bridges

scholarly journals Environmental Education as a Tool for Sustainable Development: Case study of Lekki-Lagos

2017 ◽  
Vol 1 (1) ◽  
pp. 15-22
Author(s):  
M. N. Chukwu ◽  
S. J. Kadafur
Keyword(s):  
Environmental Education ◽  
Sample Population ◽  
Traffic Jam ◽  
Qualitative Survey ◽  
Private Organizations ◽  
Pedestrian Bridges ◽  
Significant Difference ◽  
Grass Root ◽  
The Government

The study examines the strength of environmental education in Lekki-Lagos and its impact on community and grass-root development by considering a targeted sample population comprising some respondents that are living or working in Lekki community in Lagos. A qualitative survey was conducted using participatory observation, interviews, and a structured questionnaire. The questionnaire was validated through peer review and pilot testing. Data collected were summarized and computed using descriptive statistics while a paired t-test and Turkey’s HSD test were used for further analysis. Results showed that 92% of the respondents affirmed that environmental education impacted positively on the community attracting the government, non-governmental and private organizations to help in developing the area through construction of roads, pedestrian bridges, drainages and sea embankments thus reducing flooding, man hour loss due to traffic jam and rate of pollution. There was also a decrease in loss of lives and properties. Investors were attracted to Lekki, reducing poverty and social imbalance thus increasing community development. There is a significant difference between the state of Lekki now and before the intervention of public-private practice in developing the area (P< 0.05). It is recommended that the government and other stakeholders should collaborate on a higher scale to enhance developing the unreached communities.

Carbon Footprint Analysis of Fibre Reinforced Polymer (FRP) Incorporated Pedestrian Bridges: A Case Study

2012 ◽  
Vol 517 ◽  
pp. 724-729
Author(s):  
Jian Guo Dai ◽  
Tamon Ueda
Keyword(s):  
Construction Industry ◽  
Carbon Footprint ◽  
Prestressed Concrete ◽  
Environmental Friendliness ◽  
Pedestrian Bridge ◽  
Reinforced Polymer ◽  
Pedestrian Bridges ◽  
Fibre Reinforced Polymer ◽  
Footprint Analysis

This paper presents a case study on the carbon footprint of a fibre reinforced polymer (FRP)-incorporated pedestrian bridge in comparison with a conventional prestressed concrete (PC) one. The CO2 emission is used as an index and calculated for both the material manufacturing and the construction processes. It is shown that using an FRP-incorporated pedestrian bridge to replace a conventional prestressed concrete (PC) bridge may reduce the CO2 emission by 18% and 70%, respectively, during the material manufacturing and construction periods, leading to a total reduction by about 26%. Such reduction is expected to be more significant if the life-cycle CO2 emission is accounted for, since the former type of bridge is free of corrosion and almost maintenance-free. Therefore, FRP-incorporated bridges may become a more competitive alternative to conventional reinforced concrete (RC) or PC ones with the increasing attention paid on the sustainability and environmental friendliness of construction industry by our society.

scholarly journals Aeroelastic Response of Suspended Pedestrian Bridges Made of Laminated Wood and Hemp

2020 ◽  
Vol 5 (7) ◽  
pp. 60
Author(s):  
Fabio Rizzo
Keyword(s):  
Steel Structure ◽  
Wind Tunnel Experiments ◽  
Aeroelastic Response ◽  
Flutter Speed ◽  
Pedestrian Bridges ◽  
Torsional Frequency ◽  
Structural Configurations ◽  
Steel Cables ◽  
Two Degree Of Freedom

The work described in this paper investigated, by calculating critical flutter speed, the aeroelastic response of suspended pedestrian bridges made of a laminated wood structure and hemp cables and compared them to bridges with a steel structure and harmonic steel cables. Critical flutter speed was estimated using a numerical two degree of freedom (2-DOF) generalized deck model based on finite-element modal analysis. The critical flutter speeds of two sets of 25 different structural configurations, obtained by varying the deck chord and the permanent deck loads, made of steel and of laminated wood respectively, were estimated using experimental flutter derivatives obtained from 30 wind tunnel experiments. One of the most significant results was that pedestrian bridges made of laminated wood and hemp have a higher torsional frequency than those made of steel and that this affects critical flutter speed. A case study was performed and discussed by analyzing the structural and aeroelastic response of a 250 m pedestrian bridge with a 12 m deck chord and two approximately 32 m tall towers.

Section-Model Wind Tunnel Test for Flexible Suspended Pedestrian Bridges

2019 ◽  
Author(s):  
Rudolf T. Starossek ◽  
Sejin Kim ◽  
Ho-Kyung Kim
Keyword(s):  
Wind Tunnel ◽  
Dynamic Properties ◽  
Three Dimensional ◽  
Wind Tunnel Test ◽  
Stability Study ◽  
Pedestrian Bridge ◽  
Pedestrian Bridges ◽  
Section Model ◽  
Made In

<p>For most bridge decks certain assumptions and simplifications can be made in order to observe the wind interactions in a “2-D” sectional manner. In case of flexible simple suspended pedestrian bridges, the three- dimensional behavior in a mode is dominant, due to structural and dynamic properties highly different to general cable-supported bridges, therefore special considerations have to be made in section-model tests.</p><p>Typically, the section-model wind tunnel test does focus on the dominant vertical and rotational natural modes of the bridge deck, while the lateral mode is suppressed as non-governing. Since the lateral and rotational modes of the suspended pedestrian bridge occur in a coupled manner in the primary mode shape, they have to be examined as well. Various different methods to include these different behaviors in analysis and tests are discussed and applied on a case study object.</p><p>The paper will propose a modified section-model wind tunnel testing setup for a flexible suspended pedestrian bridge on the case study object of the Sogeum Mountain Suspended Pedestrian Bridge in Korea, where a section-model was made for the conventional wind-stability study in the wind tunnel.</p>

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO
Keyword(s):  
Latin America ◽  
El Salvador ◽  
Early Years ◽  
Left Wing ◽  
Internal Dynamics ◽  
Internal Coherence ◽  
The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

Culture and the plasticity of perception

2020 ◽  
Vol 43 ◽  
Author(s):  
Michael Lifshitz ◽  
T. M. Luhrmann
Keyword(s):  
Cultural Context ◽  
Sensory Experience ◽  
Cultural Learning ◽  
The World

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.

Dual systems for all: Higher-order, role-based relational reasoning as a uniquely derived feature of human cognition

2019 ◽  
Vol 42 ◽  
Author(s):  
Daniel J. Povinelli ◽  
Gabrielle C. Glorioso ◽  
Shannon L. Kuznar ◽  
Mateja Pavlic
Keyword(s):  
Temporal Reasoning ◽  
Higher Order ◽  
Important Case ◽  
Human Cognition ◽  
Relational Reasoning ◽  
Dual Systems ◽  
First Order ◽  
Reasoning System ◽  
Role Based

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.

Sociocultural memory development research drives new directions in gadgetry science

2019 ◽  
Vol 42 ◽  
Author(s):  
Penny Van Bergen ◽  
John Sutton
Keyword(s):  
Episodic Memory ◽  
Autobiographical Memory ◽  
Developmental Psychology ◽  
Cross Cultural ◽  
Memory Development ◽  
Development Research ◽  
Cultural Research ◽  
New Directions ◽  
Cross Cultural Research

Abstract Sociocultural developmental psychology can drive new directions in gadgetry science. We use autobiographical memory, a compound capacity incorporating episodic memory, as a case study. Autobiographical memory emerges late in development, supported by interactions with parents. Intervention research highlights the causal influence of these interactions, whereas cross-cultural research demonstrates culturally determined diversity. Different patterns of inheritance are discussed.

Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

1996 ◽  
Vol 54 ◽  
pp. 636-637
Author(s):  
D. L. Callahan
Keyword(s):  
Plastic Deformation ◽  
Aluminum Nitride ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Bright Field Image ◽  
Perfectly Plastic ◽  
Contrast Analysis ◽  
Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

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