Search results for "support"

Polystyrene-supported organocatalysts for alfa-selenenylation and Michael reactions. A common post-modification approach for catalytic differentiation

2011

Three different resin-supported catalysts have been prepared by using the well established post-modification approach by means of thiol-ene coupling reaction. Two catalysts were tested for the first time in the asymmetric α-selenenylation of propanal, while the third catalyst was used in the Michael addition reaction. While the preliminary results are not encouraging in the case of supported Jørgensen’ catalyst, interesting data have been collected with both for the supported MacMillan and prolyl-prolinol catalysts. In fact, these catalysts displayed good activity and selectivity. A reversed enantioselectivity in the α-selenenylation was observed by changing the polarity of the solvent. Fin…

From covalently linked catalysts to "release and catch" catalytic systems

2014

Catalytic applications of TiO2

2021

Abstract The use of TiO2 as heterogeneous catalyst and/or active support for metals or other oxides is here reported. Many reactions of industrial relevance involve, in fact, titania-based catalysts, among them, NOx abatement, Fischer–Tropsch and water–gas shift, Deacon and Claus processes, hydrodesulfurizations and hydrogenations, selective reductions and selective oxidations. This chapter aims to discuss the main applications of TiO2, in its different forms, as effective support or catalyst for thermocatalytic and photo-thermocatalytic reactions, focusing on the role of its structural and physicochemical properties on the catalytic performance (activity, selectivity, stability).

Silica powder obtained by sol-gel method as a support of organometallic vanadium catalyst for ethylene polymerization

2004

Sol-gel technique was employed to obtain the silica-type powder, which after modification procedure was applied as asupport of organometallic catalytic system for ethylene polymerization. The powder product was synthesized using hydrolysis and condensation of TEOS, catalyzed by ammonia. Obtained material and a reference support (commercial silica Davisil) were characterized to determine their particle size distributions, BET surface area, pore volume and diameter. Gas-phase adsorption of vanadium catalyst on analyzed support materials as well as adsorption from the solution in hexane were carried out. Both carrier materials were thermally pretreated prior catalytic systems syntheses and the…

Determination of glyphosate and its metabolite aminomethylphosphonic acid in fruit juices using supported-liquid membrane preconcentration method wit…

2005

Abstract The application of supported-liquid membrane (SLM) technique for effective extraction of N -(phosphonomethyl)glycine (glyphosate) and its primary metabolite aminomethylphosphonic acid (AMPA) from juices (orange, grapefruit, apple and blackcurrant) in combination with HPLC-UV detection after derivatization with p -toluenesulphonyl chloride (TsCl) is presented. The influence of various parameters such as the composition of acceptor phase, flow-rate, concentration of analytes, on the performance of extraction procedure, was studied. It was shown that by appropriate manipulation of SLM parameters the level of detection could be significantly improved. The influence of SLM conditions on…

Rozvoj matematickej intuície predškolských detí v kontexte pripravenosti na začiatok školskiej dochádzky

2014

Rozpoznawanie indywidualnych potrzeb edukacyjnych i wspieranie rozwoju uczniów w wieku wczesnoszkolnym z trudnościami w uczeniu się matematyki

2018

Palliative Care and End-of-Life Issues in Patients with Brain Cancer Admitted to ICU

2023

Background and Objectives: Palliative care is an interdisciplinary medical specialty focused on improving the quality of life of critically ill patients, including those with frailty, during their illness. Materials and Methods: We conducted an extensive literature review on Pubmed focusing on palliative care in neuro-oncology patients admitted to intensive care units (ICUs). Results: We identified 967 articles and, after excluding 952 articles in accordance with the PRISMA flow chart, we included a total of 15 articles in the final selection. The potential role of palliative care in neuro-oncology appears necessary to ensure comprehensive end-of-life patient care. However, this seems under…

Proximal versus distal contextual factors: which impact on meal pleasure and food intake in the elderly living in a nursing home?

2014

Poster présenté lors de la conférence; Introduction: Several authors pointed out the importance of meal context on food intake in nursing home. Some authors assessed the impact of context improvement on food intake in nursing home, but they assessed ‘holistic’ strategies by improving physical environment, increasing choice level, changing staff organization… (Abbott et al. 2013). Despite some of these interventions were effective, these strategies are costly and thus difficult to be implemented in nursing home. The aim of the present experiment was to assess the impact of single contextual factors, three proximal factors (food contextual factors) and three distal factors (non-food contextua…

DEVELOPMENT OF SUSTAINABLE METROPOLITAN AREAS USING A MULTI-SCALE DECISION SUPPORT SYSTEM

2012

A sustainable and sustaining planning strategy is globally important for metropolitan areas. Sustainable planning addresses the development of strategies to reduce the use of resources, increase economic efficiency and improve integration of social aspects. In contrast, splinter development (e.g. urban sprawl) involves damage to nature and generation of an increasing volume of traffic (these are the main criticisms following a study by Newman and Kenworthy (1989) on the relationship between settlement density and energy consumption). Interestingly, the overly compact city also has this effect as it may generate traffic flows for accessing green and leisure areas, or changes of residence due…