Search results for "stabilization"

Wastewater modification processes in a stabilization reservoir: a new mathematical model

2018

The paper presents a mathematical model for the simulation of the ecology of a wastewater stabilization reservoir (WSR). WSRs are hypertrophic aquatic systems devoted to water storage in warm countries where shortage conditions are often encountered. Several factors that affect the stabilization reservoir’s effluent quality were taken into account: hydraulics and hydrology, solar radiation, reaeration, algae, zooplankton, organic matter, pathogens, and sediment-water interactions. The model quantifies the specific influence of each factor on effluent quality, and evaluating the correlation between the different factors. State variables included in the model were: algae, dissolved oxygen, or…

Thermo- and photo-oxidative stability and improved processability of polyamide stabilized with a new functional additive

2005

During processing polyamides can undergo thermo-mechanical degradation due to the mechanical stress and to the high temperature applied to the melt. Degradation can occur also during the polyamides lifetime due to many driving forces, like temperature, ultraviolet radiations, etc. The mechanisms of degradation are not well understood and the stabilization with usual stabilizers, like phenol antioxidants, is not so efficient as for other classes of polymers. The aim of this work is the study of the effects of the addition of a new multifunctional additive on the processing and on the thermo- and photo-stabilization of polyamide-6. This additive is able to prevent the thermo-mechanical degrad…

Photooxidation and Stabilization of Photooxidized Polyethylene and of its Monopolymer Blends

2003

The increasing use of products from recycled polymers, or from blends with recycled polymers exposed to the outdoors, implies the need for good weathering resistance. This is particularly important when the recycled material comes, in turn, from products exposed during their lifetime to the sun. In this case the presence of C=O groups in the macromolecular chains strongly increases the photooxidative degradation kinetics of these secondary materials. In this work the change of the photooxidative degradation of blends of virgin and photooxidized polyethylene was evaluated as a function of the C=O content present in the material. As expected, the presence of the C=O groups strongly increases …

Estabilización de modelos económicos dinámicos con control óptimo en tiempo continuo

1990

En esta Tesis de Licenciatura se lleva a cabo el estudio de un problema determinado de optimización dinámica y sus aplicaciones en el campo de la Ciencia Económica. Un problema de optimización consiste, fundamentalmente, en la búsqueda de un extremo de una función o un funcional objetivo que proporcione un máximo o un mínimo para esa función. Cuando se habla de optimización dinámica hay que incorporar el factor tiempo al problema, en todas y cada una de las diferentes variables que intervienen, lo que afectará a los modelos matemáticos que se empleen para representar el comportamiento y las relaciones existentes entre dichas variables. También afecta al funcional objetivo a optimizar. Así, …

Col : A Data Collection Protocol for Vanet

2012

International audience; In this paper, we present a protocol to collect data within a vehicular ad hoc network (VANET). In spite of the intrinsic dynamic of such network, our protocol simultaneously offers three relevant properties: (1) It allows any vehicle to collect data beyond its direct neighborhood (i.e., vehicles within direct communication range) using vehicle-to-vehicle communications only (i.e., the infrastructure is not required); (2) It tolerates possible network partitions; (3) It works on demand and stops when the data collection is achieved. To the best of our knowledge, this is the first collect protocol having these three characteristics. All that is chiefly obtained thanks…

Robust delay-dependent H∞ control of uncertain time-delay systems with mixed neutral, discrete, and distributed time-delays and Markovian switching p…

2011

Author's version of an article published in the journal: IEEE Transactions on Circuits and Systems I: Regular Papers. Also available from the publisher at: http://dx.doi.org/10.1109/tcsi.2011.2106090 The problem of robust mode-dependent delayed state feedback H ∞ control is investigated for a class of uncertain time-delay systems with Markovian switching parameters and mixed discrete, neutral, and distributed delays. Based on the LyapunovKrasovskii functional theory, new required sufficient conditions are established in terms of delay-dependent linear matrix inequalities for the stochastic stability and stabilization of the considered system using some free matrices. The desired control is …

Substituent effects of nitro group in cyclic compounds

2020

AbstractNumerous studies on nitro group properties are associated with its high electron-withdrawing ability, by means of both resonance and inductive effect. The substituent effect of the nitro group may be well described using either traditional substituent constants or characteristics based on quantum chemistry, i.e., cSAR, SESE, and pEDA/sEDA models. Interestingly, the cSAR descriptor allows to describe the electron-attracting properties of the nitro group regardless of the position and the type of system. Analysis of classical and reverse substituent effects of the nitro group in various systems indicates strong pi-electron interactions with electron-donating substituents due to the re…

Biomarker responses by crucian carp () living in a pond of secondary treated pulp mill effluent

1999

Biochemical and histological biomarkers by the adult crucian carp ( Carassius carassius (L.)) living in a biologically treated pulp mill effluent were studied. Enocell pulp mill in Uimaharju, Finland, discharges its effluents through a waste water pond to the River Pielisjoki. This pond harbours an introduced crucian carp population that apparently reproduces on site. The objective of the present study was to measure possible hormonal effects of treated pulp mill effluent on crucian carps living in a wastewater pond. Adult fish were collected for analysis by traps. A reference population was sampled from a small natural pond. Blood and bile samples were taken for analyses of hemoglobin, hem…

On the critical velocities and free vibrations of axially moving elastic webs

2014

Resveratrol post-transcriptionally regulates pro-inflammatory gene expression via regulation of KSRP RNA binding activity

2014

Resveratrol shows beneficial effects in inflammation-based diseases like cancer, cardiovascular and chronic inflammatory diseases. Therefore, the molecular mechanisms of the anti-inflammatory resveratrol effects deserve more attention. In human epithelial DLD-1 and monocytic Mono Mac 6 cells resveratrol decreased the expression of iNOS, IL-8 and TNF-α by reducing mRNA stability without inhibition of the promoter activity. Shown by pharmacological and siRNA-mediated inhibition, the observed effects are SIRT1-independent. Target-fishing and drug responsive target stability experiments showed selective binding of resveratrol to the RNA-binding protein KSRP, a central post-transcriptional regul…