scholarly journals Role of sequestration of CO2 due to the carbonation in total CO2 emission balance in concrete life

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Piotr P. Woyciechowski ◽  
Keyword(s):  
Carbon Footprint ◽  
Secondary Phase ◽  
Cement Concrete ◽  
Concrete Carbonation ◽  
Complex Process ◽  
Sequestration Potential ◽  
Concrete Production ◽  
Co2 Balance ◽  
Construction Works

Calculation of the carbon footprint of cement concrete is a complex process including consideration of the phase of primary life (components and concrete production processes, transportation, construction works, maintenance of concrete structures) and secondary life, including demolition and recycling. Taking into consideration the effect of concrete carbonation can lead to a reduction in the calculated carbon footprint of concrete. In this paper, an example of CO2 balance for small bridge elements made of Portland cement reinforced concrete was done. The results include the effect of carbonation of concrete in a structure and of concrete rubble after demolition. It was shown that important impact of carbonation on the balance is possible only when rubble carbonation is possible. It was related to the fact that only the sequestration potential in the secondary phase of concrete life has significant value.

Social Cohesion, Breaks, and Transformations in Italy, 535–600

2018 ◽  
Author(s):  
Walter Pohl
Keyword(s):  
The Political ◽  
Late Antique ◽  
Religious Context ◽  
Ancient Society ◽  
Complex Process ◽  
Term Change ◽  
Two Generations ◽  
Classical Culture

When the Gothic War began in Italy in 535, the country still conserved many features of classical culture and late antique administration. Much of that was lost in the political upheavals of the following decades. Building on Chris Wickham’s work, this contribution sketches an integrated perspective of these changes, attempting to relate the contingency of events to the logic of long-term change, discussing political options in relation to military and economic means, and asking in what ways the erosion of consensus may be understood in a cultural and religious context. What was the role of military entrepreneurs of more or less barbarian or Roman extraction in the distribution or destruction of resources? How did Christianity contribute to the transformation of ancient society? The old model of barbarian invasions can contribute little to understanding this complex process. It is remarkable that for two generations, all political strategies in Italy ultimately failed.

Role of secondary phase particles in fatigue behavior of high-speed railway gearbox material

2020 ◽  
Vol 131 ◽  
pp. 105336 ◽  
Author(s):  
Yinan Jiao ◽  
Yifan Zhang ◽  
Shiqing Ma ◽  
Deli Sang ◽  
Yang Zhang ◽  
...  
Keyword(s):  
High Speed ◽  
Fatigue Behavior ◽  
Secondary Phase ◽  
High Speed Railway

scholarly journals Consciousness, decision making, and volition: freedom beyond chance and necessity

2021 ◽  
Author(s):  
Hans Liljenström
Keyword(s):  
Decision Making ◽  
Free Will ◽  
Brain Activity ◽  
Brain Structures ◽  
Complex Process ◽  
Neural Information ◽  
Neural Information Processing ◽  
Stochastic Population Model ◽  
The Brain

AbstractWhat is the role of consciousness in volition and decision-making? Are our actions fully determined by brain activity preceding our decisions to act, or can consciousness instead affect the brain activity leading to action? This has been much debated in philosophy, but also in science since the famous experiments by Libet in the 1980s, where the current most common interpretation is that conscious free will is an illusion. It seems that the brain knows, up to several seconds in advance what “you” decide to do. These studies have, however, been criticized, and alternative interpretations of the experiments can be given, some of which are discussed in this paper. In an attempt to elucidate the processes involved in decision-making (DM), as an essential part of volition, we have developed a computational model of relevant brain structures and their neurodynamics. While DM is a complex process, we have particularly focused on the amygdala and orbitofrontal cortex (OFC) for its emotional, and the lateral prefrontal cortex (LPFC) for its cognitive aspects. In this paper, we present a stochastic population model representing the neural information processing of DM. Simulation results seem to confirm the notion that if decisions have to be made fast, emotional processes and aspects dominate, while rational processes are more time consuming and may result in a delayed decision. Finally, some limitations of current science and computational modeling will be discussed, hinting at a future development of science, where consciousness and free will may add to chance and necessity as explanation for what happens in the world.

scholarly journals Building Bridges: A Participatory Stakeholder Framework for Sustainable Urban Construction Logistics

2021 ◽  
Vol 13 (5) ◽  
pp. 2678
Author(s):  
Nicolas Brusselaers ◽  
Koen Mommens ◽  
Cathy Macharis
Keyword(s):  
Urban Areas ◽  
Sustainable Construction ◽  
Environmental Footprint ◽  
Implementation Barriers ◽  
Urban Construction ◽  
Multi Level ◽  
Negative Impacts ◽  
Roll Out ◽  
Construction Works

The urban built environment concentrates due to the growing urbanization trend, triggering construction and renovation works in urban areas. Although construction works often revitalize cities upon completion, the associated logistics activities engender a significant financial and environmental footprint if not handled appropriately. Cities have the largest potential to reduce negative impacts through requirements on construction logistics. However, today, there is a lack of knowledge within cities on how to set such demands and how to involve and manage the numerous and varying stakeholders in these processes. This paper presents a participatory decision-making framework for the governance of urban construction logistics on economic, environmental and societal levels, building further on the Multi-Actor Multi-Criteria Analysis (MAMCA). The framework was then implemented on a use case in the dense urban Brussels-Capital Region (Belgium), gathering a wide variety of stakeholders in the context of a sustainable Construction Logistics Scenario (CLS) evaluation. Special attention was paid on the identification of implementation barriers and the role of governments to facilitate the introduction and city-wide roll-out of novel CLS. Findings show how different processes are site-, actor- and condition-specific, thereby delivering a common built object which is often based on different motivations and concerns. The study proposes a flexible, replicable and upscalable framework both from an inter- and intracity perspective, which can serve to support (1) the management of processes and CLS, (2) the management of people and the community, and (3) the project and city, in the context of multi-level governance.

Compressive behaviours, splitting properties, and workability of lightweight cement concrete: The role of fibres

2022 ◽  
Vol 320 ◽  
pp. 126237
Author(s):  
Baifa Zhang ◽  
Yuan Feng ◽  
Jianhe Xie ◽  
Jianhua He ◽  
Ting Yu ◽  
...  
Keyword(s):  
Cement Concrete

scholarly journals Revisiting the Organic Template Model through the Microstructural Study of Shell Development in Pinctada margaritifera, the Polynesian Pearl Oyster

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 370 ◽  
Author(s):  
Jean-Pierre Cuif ◽  
Yannicke Dauphin ◽  
Gilles Luquet ◽  
Kadda Medjoubi ◽  
Andrea Somogyi ◽  
...  
Keyword(s):  
Pearl Oyster ◽  
Nacreous Layer ◽  
Prismatic Layer ◽  
Pinctada Margaritifera ◽  
Microstructural Study ◽  
Leading Role ◽  
Complex Process ◽  
Gathering Data

A top-down approach to the mineralized structures and developmental steps that can be separated in the shells of Pinctada margaritifera was carried out. Detailed characterizations show that each of the two major layers usually taken into account (the outer prismatic layer and the inner nacreous layer) is actually the result of a complex process during which the microstructural patterns were progressively established. From its early growing stages in the deeper part of the periostracal grove up to the formation of the most inner nacreous layers, this species provides a demonstrative case study illustrating the leading role of specifically secreted organic structures as determinants of the crystallographic properties of the shell-building units. Gathering data established at various observational scales ranging from morphology to the nanometer level, this study allows for a reexamination of the recent and current biomineralization models.

scholarly journals Sustainable Geometric and Bio-Cultural/Cultural Models of Human Society: The Role of Non-Capitalist Cooperation in Times of Civilizational/Environmental Crisis

2017 ◽  
Vol 10 (2) ◽  
pp. 13
Author(s):  
M. S. Sthel ◽  
J. G. R. Tostes ◽  
J. R. Tavares
Keyword(s):  
Carbon Footprint ◽  
Cultural Models ◽  
Total Carbon ◽  
Environmental Crisis ◽  
Human Society ◽  
Capitalist System ◽  
Equilateral Triangles ◽  
Footprint Area ◽  
The Individual

The Sustainable Complex Triangular Cells (SCTC) and bio-cultural/cultural models of human society are employed here. Regarding SCTC model, the cell areas represent the individual´s carbon footprint. Scalene triangles represent each individual in the present competitive standard (inward arrows). Equilateral triangles (outward arrows) are “summed” so as forming cooperative-hexagonal bodies leading to a collaborative model of society, reducing the total carbon footprint area as regard the formal analogous sum of each individual (inward) non-cooperative triangle. We particularly have focused on environmental global limits of the capitalist system, with SCTC modeling an accelerated global anti-ecological “scalenization” process from the 29 crisis to the present neoliberal stage of capitalism. Employing again the SCTC model, we describe and exemplify instable and short lifetime “islands” built up through evanescent local process of “cooperative equilateralization” (outward arrows) in the last 40 years. Such non-capitalist features were “mixed in” with competitive “scalenized” features of the capitalist “ocean”. In the final topic, we will consider bio-cultural (Nowak and Wilson) models of the human history and a cultural (Weber-Alberoni) model for great inflexions in the western history. All these models intersect via human cooperation. Particularly, that last model is complementary to the above small and instable “islands” sketch: but now we deal with western religious and secular, non- capitalist, purely cooperative experiences, which correspond to the above labeled SCTC “cooperative equilateralization”. Such weber-alberonian “islands” may be – some few times - sufficiently stable for rapid and great expansions leading, e.g., to a “civilizational/environmental jump” in the presently menaced planet.

The Role of Nb2Zr6O17 Phase on the Hardness and Fracture Toughness of ZTA/Nb2O5 by Cold Isostatic Pressing

2017 ◽  
Vol 888 ◽  
pp. 126-130 ◽  
Author(s):  
Nurul Khairunnisa Su ◽  
Muhammad Fadhlullah Al Amin Abdul Razak ◽  
Johar Banjuraizah ◽  
Muhammad Asri Idris ◽  
Zainal Arifin Ahmad
Keyword(s):  
Fracture Toughness ◽  
Vickers Hardness ◽  
Secondary Phase ◽  
Cold Isostatic Pressing ◽  
Cip Method ◽  
X Ray ◽  
Isostatic Pressing ◽  
Zirconia Toughened Alumina ◽  
Scanning Electron

The microstructure and mechanical properties of zirconia toughened alumina (ZTA) ceramic added with niobia (Nb2O5) through cold isostatic pressing (CIP) method was investigated. The amount of Nb2O5 is varied from 0 wt.% to 7 wt.%. The phase composition of the sintered bodies was analyzed with an x-ray diffractometer, while their microstructure was observed with a scanning electron microscope. It is found that up to 3 wt.% of Nb2O5 addition, the secondary phase of Nb2Zr6O17 presence as square shape particles confirm by SEM and EDX. The addition of 3 wt.% showed the highest Vickers hardness value with 1600HV. It was observed that, further addition of Nb2O5 (> 3 wt.% ) deteriorates the Vickers hardness of ZTA. While the fracture toughness value increased at 3 wt.% until 5 wt.% of Nb2O5 addition (6.71 MPa · √m and 6.80 MPa · √m respectively). It was also found that the value for bulk density increased and porosity decreased with the increasing of Nb2O5 addition.

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