791 research outputs found
A hydrodynamic model arising in the context of granular media
AbstractIn this note, we propose a formal argument identifying the hydrodynamic limit of a Fokker-Planck model for granular media appearing in [1]. More precisely, in the limit of large background temperature and vanishing friction, this hydrodynamic limit is described by the classical system of isentropic gas dynamics with a nonstandard pressure law (specifically, the pressure is proportional to the cube root of the density). Finally, some qualitative properties of the hydrodynamic model are studied
Strong Convergence towards self-similarity for one-dimensional dissipative Maxwell models
We prove the propagation of regularity, uniformly in time, for the scaled
solutions of one-dimensional dissipative Maxwell models. This result together
with the weak convergence towards the stationary state proven by Pareschi and
Toscani in 2006 implies the strong convergence in Sobolev norms and in the L^1
norm towards it depending on the regularity of the initial data. In the case of
the one-dimensional inelastic Boltzmann equation, the result does not depend of
the degree of inelasticity. This generalizes a recent result of Carlen,
Carrillo and Carvalho (arXiv:0805.1051v1), in which, for weak inelasticity,
propagation of regularity for the scaled inelastic Boltzmann equation was found
by means of a precise control of the growth of the Fisher information.Comment: 26 page
What happens at the aroma of coffee beans after roasting?
The coffee aroma is one of the most important quality evaluation criteria employed for coffee commercialization and consumption.
The purpose of this study was following the roasting process VOCs creations with the novel Electronic Nose equipped whit 2 of 6 MOX nanowire sensors.
The nanowires exhibit exceptional crystalline quality and a very high length-to-width ratio, resulting in enhanced sensing capability as well as long-term material stability for prolonged operation.
Four different methods of roasting, made by ROSTAMATIC (Table 1) machine, were applied to gain a clearer picture of the differences in roasted coffee aromas by means of a volatile compound analysis. Different methods applied on four different origins of green coffee (India, Indonesia, Honduras, Santos and Nicaragua).
The commercial coffees products are made from a blending from minimum five different kinds of coffee and the consumers have developed an addiction/expectation to a specific flavor and taste. Different methods of roasting process will provide the coffee different aroma that will add flexibility to those one that already posses the matrix due to different origins.
This work tests and illustrates the broad spectrum of potential uses of the EN technique in food quality control
2-D constrained Navier-Stokes equation and intermediate asymptotics
We introduce a modified version of the two-dimensional Navier-Stokes
equation, preserving energy and momentum of inertia, which is motivated by the
occurrence of different dissipation time scales and related to the gradient
flow structure of the 2-D Navier-Stokes equation. The hope is to understand
intermediate asymptotics. The analysis we present here is purely formal. A
rigorous study of this equation will be done in a forthcoming paper
Candida milleri detected by Electronic Nose in tomato sauce
AbstractThe tomato sauce is a product of great importance for its massive production in Italy. Microbial contamination is a constant concern for the industries, causing severe economic losses, posing risks to consumers’ health and contributing to an enormous wasting of food. This work shows how the use of the Electronic Nose (EN) EOS 507C can be effective compare to the current procedures in the food production. EN composed of an array of thin film sensors, 6 Metal Oxide (MOX). All the samples were analyzed in parallel with classical chemical technique, like GC-MS with SPME
Prosecuting Trafficking Crimes for Sexual Exploitation in Times of Conflict: Challenges and Perspective
This article explores the nexus between conflict-related sexual violence and trafficking for sexual exploitation in times of conflict from a prosecutorial perspective. More specifically, it analyses whether those responsible for conflict-related sexual violence can be prosecuted under domestic and international provisions for human trafficking for sexual exploitation in times of conflict. While this practice is broadly condemned, a lot must still be done to combat the culture of impunity. Focusing on the 13 countries identified by the Secretary-General as currently affected by conflicts, the first part of the article analyses the existent domestic legal framework on human trafficking and gender-related violence. This perusal reveals that national legislation is generally inadequate to comprehensively address these issues. With few exceptions, the domestic frameworks fail to comply with international recognised standards and enforcement challenges in time of conflict complicate further the application and implementation of these provisions for an effective prosecution. Concluding that no prospect of successful convictions exists under national law, the second part of this paper discusses the possibility of international prosecution. Even if the International Criminal Court (ICC) might have jurisdiction on the alleged crimes, this paper highlights that the crime of trafficking is not explicitly criminalised in the Rome Statute as such and its qualification as ‘sexual slavery’ or ‘enslavement’ is ambiguous. Nevertheless, the ICC could expand the definition of these two crimes to include the crime of trafficking for the purpose of sexual exploitation. However, the ICC has not yet prosecuted anybody for trafficking despite the existence of evidence on this crime in some of the states under investigation. In light of this analysis, this article concludes that there are little prospects of successful prosecution for those responsible for human trafficking because both the domestic and international framework have significant limitations, both internal and external and not sufficient deterrent force. Therefore, it suggests that the international community should keep pushing these 13 countries to improve their domestic legislation up to recognised international standards and the ICC to address the interpretative challenges posed by the crime of trafficking
Physiological and driving behaviour changes associated to different road intersections
Road traffic injuries claim more than 1.2 million lives each year in the world and have a huge impact on health and development. It is commonly acknowledged that the human factor and the interaction between the human factor and the road environment are among the most common causes of road accidents. Intersections are among the most complex road environments: their geometric and traffic characteristics weigh the driver workload, affecting the driving behaviour and consequently the risk of accident. This study intends therefore to contribute for a better understanding of the relationship between different types of intersection and the human factor. The ultimate aim is to understand how at grade intersections affect the driving behaviour by comparing the drivers’ stress level for roundabouts and standard intersections. Electrodermal activity can provide a real-time assessment of the driver's stress level. Electrodermal activity was therefore collected continuously during a driving study which took place on a test environment based at Cranfield University and surrounding roads. Twenty participants were involved within the study. The analysis focused on four crossing manoeuvres on three at grade intersections (two T-junctions and a roundabout) situated on the study location. Results showed that the number of SCR peaks as well as the amplitude of the peaks are overall higher for the two manoeuvres on the roundabout. The stress level induced by each type of intersection was evaluated through an Electrodermal Impact Index which takes into account both the number and the amplitude of SCR peaks. Results suggested that the stress level induced by roundabouts is more than double that induced by standard intersections
The Cauchy problem for the 3-D Vlasov-Poisson system with point charges
In this paper we establish global existence and uniqueness of the solution to
the three-dimensional Vlasov-Poisson system in presence of point charges in
case of repulsive interaction. The present analysis extends an analogeous
two-dimensional result by Caprino and Marchioro [On the plasma-charge model, to
appear in Kinetic and Related Models (2010)].Comment: 28 page
Numerical Analysis on the Optimisation of Thermal Comfort Levels in an Office Located inside a Historical Building
The present study examines the possibility of thermal comfort optimisation inside an office room where, due to historical heritage, it is possible to modify neither the energetic characteristic of the envelope nor the position of the inlet air vents. The distribution of global and local thermal comfort indices is evaluated in both heating and cooling conditions by establishing a computational fluid dynamics (CFD) model validated against experimental data. The obtained results demonstrate a striking asymmetry of the air velocity and temperature distribution due to the low energy efficiency of the building. In heating mode, the predicted mean vote (PMV) values were improved if the discharged air from the fan coil was at its maximal velocity. However, at the same time, the vertical
air temperature gradient increased by around 0.5 C in each working station. In the cooling condition, in the absence of the solar radiation, the minimal air-flow rate satisfied the acceptable range of the draught rate (DR), whereas in the presence of a solar load, it could not meet the required cooling load in all positions, leading to higher floor temperature. The findings of this study allow for identifying and rearranging the optimal position of working stations in terms of thermal comfort
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