Search results for "heterogeneous"

Photocatalytic degradation of acid blue 80 in aqueous solutions containing TiO2 suspensions.

2001

The photocatalytic degradation of the anthraquinonic dye Acid Blue 80 in aqueous solutions containing TiO2 dispersions has been investigated. The process has been monitored by following either the disappearance of the dye (via HPLC) and the formation of its end-products (via IC, GC, and TOC analysis). Although a relatively fast decolorization of the solutions has been observed, the mineralization is slower, and the presence of residual organic compounds was evidenced even after long term irradiation, confirming the relevant stability of anthraquinone derivatives. The identification of various unstable intermedi ates formed after low irradiation times was performed by HPLC-MS, allowing us to…

Titania Photocatalysts for Selective Oxidations in Water

2011

Heterogeneous photocatalysis by polycrystalline semiconductor oxides is an unconventional technology that has been mainly applied for the degradation of organic and inorganic pollutants in both the vapor and liquid phase. The application of photocatalysis in synthetic routes has also been researched in recent years, demonstrating its viability as an alternative route in organic chemistry. This work illustrates the main findings in the application of heterogeneous photocatalysis to the oxidation of organic compounds dissolved in water, free of any organic co-solvent. Two main aspects of the oxidative process have been studied: the first one is the partial oxidation of various mono-substitute…

2017

A hybrid bioinspired material with manganese(II) complexes grafted on the surface of a mesostructured porous silica is investigated. The Mn sites mimic the manganese-dependent dioxygenase (MndD), which is an enzyme that catalyses the oxidation of catechol derivatives. The metal complexes were introduced in the silica using a dinuclear complex [Mn2L2(Cl)2(μ-Cl)2] as a precursor with a clickable ligand N,N′-bis[(pyridin-2-yl)methyl]prop-2-yn-1-amine (L). Azide moieties covalently grafted on MCM-41 type mesoporous silica were utilised to anchor the manganese complex through Huisgen cycloaddition using CuBr(PPh3)3 as a catalyst. A second functional group – trimethylsilyl or pyridine—was grafted…

A new efficient, highly dispersed, Pd nanoparticulate silica supported catalyst synthesized from an organometallic precursor. Study of the homogeneou…

2018

[EN] A new Pd(0) catalyst supported on silica UVM-7 has been synthesized from the organometallic [Pd-2(mu-(C6H4) Pp(2))(2)(CH3CN)(4)](BF4)(2) precursor, characterized by the high dispersion, activity, and small size of the palladium nanoclusters fixed on the silica surface. The catalyst was tested for the Suzuki-Miyaura (SM) reaction of different 4-substitutedphenyl halides with phenylboronic acid. The kinetic study concurs with most of the catalytic action was carried out by Pd species originated by the partial solubilization of Pd immobilized on mesoporous silica. The Schmidt's analysis of differential selectivity (SADS) in several competitive SM reactions, together the STEM-HAADF and HRT…

The KH-type splicing regulatory protein (KSRP) regulates type III interferon expression post-transcriptionally.

2019

Abstract Type III interferons (IFNs) are the latest members of the IFN family. They play an important role in immune defense mechanisms, especially in antiviral responses at mucosal sites. Moreover, they control inflammatory reactions by modulating neutrophil and dendritic cell functions. Therefore, it is important to identify cellular mechanisms involved in the control of type III IFN expression. All IFN family members contain AU-rich elements (AREs) in the 3′-untranslated regions (3′-UTR) of their mRNAs that determine mRNA half-life and consequently the expressional level of these cytokines. mRNA stability is controlled by different proteins binding to these AREs leading to either stabili…

MP2P Network in Collecting Data from Sensor Networks

2006

Wireless sensor networks provide numerous applications today. At the same time modern wireless short-range communication technologies combined with mobile users create environments for mobile peerto- peer networks. This paper discusses a concept of an application in which an MP2P network is used for collecting sensor network data. This model requires certain places with a high mobile user density in order to function. Simulation results indicate that the model can be used in environments where these requirements are met.

Multilayered supported ionic liquids as catalysts for chemical fixation of carbon dioxide

2011

Multilayered, covalently supported ionic liquid phase (mlc-SILP) materials were synthesized by using a new approach based on the grafting of bis-vinylimidazolium salts on different types of silica or polymeric supports. The obtained materials were characterized and tested as catalysts in the reaction of supercritical carbon dioxide with various epoxides to produce cyclic carbonates. The material prepared by supporting a bromide bis-imidazolium salt on the ordered mesoporous silica SBA-15 was identified as the most active catalyst for the synthesis of cyclic carbonates and displayed improved productivity compared with known supported ionic liquid catalysts. The catalyst retained its high act…

Benchmarking of VoIP over HSDPA and LTE performance with realistic network data

2010

The purpose of this paper is benchmark the performance of voice over IP in high speed downlink packet access and in long term evolution networks. Benchmarking is conducted in homogeneous and heterogeneous scenario layouts assuming realistic propagation data generated over Tokyo map. Tools used in this paper are two fully dynamic time driven system simulators which have been used to support 3GPP standardization work. This benchmarking study provides insights to what e.g. different radio access technologies, scheduling mechanisms and receivers do for the performance of voice over IP. This paper indicated in various scenarios that long term evolution can offer higher performance for voice over…

Multi-robot Interacting Through Wireless Sensor Networks

2007

This paper addresses the issue of coordinating the operations of multiple robots in an indoor environment. The framework presented here uses a composite networking architecture, in which a hybrid wireless network, composed by commonly available WiFi devices, and the more recently developed wireless sensor networks. Such architecture grants robots to enhance their perceptive capabilities and to exchange information so as to coordinate actions in order to achieve a global common goal. The proposed framework is described with reference to an experimental setup that extends a previously developed robotic tour guide application in the context of a multi-robot application.

Structural, energetic and kinetic database of catalytic reactions: Benzyl alcohol to benzaldehyde oxidation on MnOx clusters

2021

Abstract Data here reported are connected with the research article “Benzyl Alcohol to Benzaldehyde Oxidation on MnO x Clusters: Unraveling Atomistic Features” Gueci et al. [1] . This work described and discussed structural and energetic results, calculated by Density Functional Theory (DFT). In order to get kinetic information, DFT results were refined by an original approach, which will be shortly described in the following article. The crossed analysis of experimental and computational energetic and kinetic data allowed to (i) reconstruct the complicated lattice that connects the primary and secondary mechanisms of the reaction and (ii) identify alternative process pathways capable of by…