Search results for "agglomeration"
showing 10 items of 88 documents
Nano composite membrane-electrode assembly formation for fuel cell-modeling aspects
2007
Long term stability is an essential requirement for fuel cell applications in automobile and stationary energy systems. In these systems the agglomeration of the catalyst nanoparticles is a well-known phenomenon which cannot be easily overcome or compensated for by re-designing the system. A direct result of this occurrence is the irreversible decrease of the electrochemical performance. Irregularities in electric field distribution are one root cause for migration and subsequent agglomeration of the catalyst nanoparticle. In this work, the impact of the electrode mechanical deformation on electric field distribution was studied using a computer modeling approach. Model of a Proton Exchange…
Changes of Commuting Range in Riga Agglomeration
2018
Abstract The aim of this paper is to characterise commuting trends in Riga agglomeration, while taking into account proximity to Riga and territorial accessibility. Changes of commuting range are looked at through literature analysis (historical context) and by using descriptive analysis and parametric tests (current situation). Results indicate that while both proximity to Riga and access to state level roads have a significant impact on commuting flows, it is the former which has a more significant impact.
The Monocentric Model and After
1998
International audience
Population Growth and Manufacturing Real Wages in 18th Century England: A Spatial Perspective
2004
We develop a two-region population growth model of economic geography and show that a process of urbanization has a substantial impact on the evolution of manufacturing real wages. Whereas real wages decline as the population increases when the spatial structure of the economy is fixed, they actually rise in the long-run when factors are mobile. Agglomeration may hence be seen as a rational response to declining real wages and provides a new explanation of why manufacturing real wages did not decline prior to the Industrial Revolution in England, despite a historically unprecedented population growth.
L’habitat perché du Malpas à Soyons (Ardèche) durant l’Antiquité tardive : état des données
2023
International audience; Recent excavations carried out between 2011-2016 in the ancient and medieval town of Soyons (Ardèche), located in the middle Rhône valley, in the territory of the roman colony of Valence, provide us new data on the occupation of the hilltop of Le Malpas.The study of the fortification of the Iron age has revealed the existence of a rampart built during the 3rd century AD. At this time, the lower city, under the actual village, is gradually abandoned. After a probable hiatus during the 4th century AD, the hilltop and the lower city grew again during the 5th and the 6th century AD. The late antique artefacts discovered in all the trenches dug on the Malpas let us assume…
Neoclassical growth, manufacturing agglomeration, and terms of trade
2007
This paper presents an integrated view of economic growth, development traps, and economic geography. We explain why there is income convergence among some countries (neoclassical regime) and income divergence among others (poverty trap regime). Income convergence (divergence) and manufacturing industry diffusion (agglomeration) are re-enforcing each other in a cumulative process. Moreover, trade openness may trigger a catch-up process of an economy that is stuck in a \"poverty trap\". This catch-up is characterized by an increase in the investment-to-GDP ratio and an improvement of the terms of trade. A new dynamic welfare gain of trade liberalization is identified, which is likely to be l…
Air gasification of wood chips, wood pellets and grass pellets in a bubbling fluidized bed reactor
2021
Abstract Gasification is an attractive method for biomass-to-energy conversion and fluidized bed design is one of the best options for large scale operation. A bubbling fluidized bed reactor was used to analyze the effects of biomass type, equivalence ratio (ER) and temperature for product gas compositions. Wood chips, wood pellets and grass pellets were gasified between 650 °C and 800 °C temperature. The ER was varied between 0.08 and 0.16. Gasification of grass pellets was difficult at 800 °C due to agglomeration and the gas composition was poor compared to wood. The reactor performances improved over the temperature and 650 °C was not sufficient to achieve a reasonable carbon conversion.…
First-principles insight into CO hindered agglomeration of Rh and Pt single atoms on m-ZrO2
2020
In this first-principles study we evaluate the thermodynamic and kinetic stability of Rh and Pt single-atoms (SAs) and subnano clusters on the monoclinic zirconia surface with and without a CO atmosphere. To address the kinetic stability and agglomeration of SAs to clusters and nanoparticles, a non-equilibrium nanothermodynamic approach is developed and parametrised using data computed with density functional theory. The bare subnano clusters are more stable than SA and become more so with increasing size, which means the agglomeration is always favoured. CO binds strongly to the single atoms and clusters, and our atomistic thermodynamics treatment indicates that some CO will be present eve…
Effect of processing temperature and mixing time on the properties of PP/GnP nanocomposites
2020
Abstract During processing of molten polymers the thermal and mechanical stress acting on the melt in presence of oxygen can induce degradation with a modification of the chemical structure of the polymers. This picture can become even more relevant if the melt is a multiphasic polymer system. In this last case, the effects of the degradation depend also on the presence of a second phase and on the interactions between the two phases. In this work, the effect of the processing conditions, temperature and time, have been considered in order to investigate the thermo-mechanical and thermo-oxidative degradation of nanocomposites made by polypropylene and different contents of graphene nanoplat…
A Multi-scalar Approach to Long-Term Dynamics, Spatial Relations and Economic Networks of Roman Secondary Settlements in Italy and the Ombrone Valley…
2019
AbstractIn Roman landscapes, the particular sites defined as secondary settlements (also known as vici/villages, minor centres, agglomérations secondaires and/or stationes/mansiones) have played an ‘intermediary’ role between the cities and other rural structures (villae/farms), linked to medium- and long-distance economic and commercial trajectories. The aim of this paper is to apply a multi-scalar approach to model their long-term spatial relationships and connectivity with the Mediterranean exchange network. On the macro-scale, we have analysed a sample of 219 reviewed sites to understand the diachronic trends and spatial dynamics of attraction/proximity to significant elements of the la…