Search results for "Onium"

A Study of Osmosis Rate Through Several Proton Conducting Polymer Composite Membranes

2021

Carbon dioxide is typically considered to be a byproduct of various industrial processes that should not be released into the environment due to its nature as a harmful greenhouse gas. One of the more promising ways to dispose of it in an economical and environmentally friendly way is by using it as a raw material in electrochemical synthesis reactors. An important part of such reactors is an ion exchange membrane. In this study the influence of ZrO2 content in SPEEK – ZrO2 composite membranes on rate of osmosis trough them was investigated, with the goal of evaluating ZrO2 as an additive for making ion exchange membranes with fine-tuned osmotic permeability.

Lifetimes of intruder states in [sup 186, 188]Pb and [sup 194]Po

2006

Estudio de los taxa afines a Limonium vulgare Miller de marismas de Portugal Continental

2012

Master de Biodiversidad: Conservacion y evolucion - Universitat de Valencia. Facultat de Ciencies Biologiques / Instituto Superior de Agronomia The genus Limonium Miller is a highly complex taxonomic group and a large number of micro-species has been described as a result of their reproductive strategies, sexual and/or apomixis. In Portugal, there are few and old studies on Limonium species, although the country has exceptional conditions for their presence, given that they inhabit rocky cliffs, beaches and salt-marshes. This study was intended to clarify the identity of ambiguous specimens related to taxon Limonium vulgare Miller, typical in the salt-marshes of Continental Portugal. We per…

DFT Prediction of Enhanced Reducibility of Monoclinic Zirconia upon Rhodium Deposition

2018

Oxides are an important class of materials and are widely used, for example, as supports in heterogeneous catalysis. In a number of industrial catalytic processes, oxide supports actively participate in chemical transformations by releasing lattice oxygen anions. While this is intuitively understood for reducible oxides, the reducibility of irreducible oxides may be modified via nanoengineering or upon inclusion of foreign species. Our calculations predict that the ability of irreducible monoclinic zirconia to release oxygen improves substantially upon deposition of rhodium. Through a comprehensive screening of Rh/ZrO2 with different size of the rhodium species, we find that a Rh adatom and…

Synthesis of trans-disubstituted-2,3-dihydrobenzofurans by a formal [4 + 1] annulation between para-quinone methides and sulfonium salts

2018

An efficient protocol for the synthesis of trans-disubstituted-2,3-dihydrobenzofurans through [4 + 1] annulation of para-quinone methides with sulfonium salts has been developed. Under very mild conditions this unprecedented reaction occurs in good to excellent yields (up to 99%), offering a straightforward access to a variety of 2,3-dihydrobenzofurans.

Method for Reproducible Shipboard Segmented Flow Analysis Ammonium Measurement Using an In-House Reference Material for Quality Control

2021

Ammonium is a fundamental nutrient for phytoplankton growth in seawater and is a key component of the microbial loop. Ammonium measured in parallel with other nutrients is crucial in understanding the small temporal scale changes in oceanographic ecology. Despite the importance of measuring ammonium at sea, owing to its lability, there is no consensus on the best method. The lack of availability of certified reference materials for ammonium in seawater also makes it difficult to assess the accuracy and reproducibility of ammonium measurements. In this study we present a modified segmented flow analysis method using ortho-phthaldialdehyde (OPA) with fluorescence detection to measure ammonium…

The use of calcined paper mill sludge as a chemical precipitant in the simultaneous removal of ammonium and phosphate : paper mill waste recycling an…

2020

Currently, recycling and re-use of materials is extremely important due to the diminishing of natural resources. The objective of the European Union’s circular economy strategy is to increase recycling and the use of industrial waste materials and side streams as secondary raw materials. In this study, a chemical precipitation method to simultaneously remove ammonium nitrogen and phosphate from the liquid phase of anaerobic digestate using calcined paper mill sludge was studied. Papermill sludge is a waste material that forms in the paper-making process. In addition, commercial calcium oxide (CaO) was used as a reference precipitant. The suitability of the formed precipitate’s composition f…

Autochthonous organic matter promotes DNRA and suppresses N2O production in sediments of the coastal Baltic Sea

2021

Coastal environments are nitrogen (N) removal hot spots, which regulate the amount of land-derived N reaching the open sea. However, mixing between freshwater and seawater creates gradients of inorganic N and bioavailable organic matter, which affect N cycling. In this study, we compare nitrate reduction processes between estuary and offshore archipelago environments in the coastal Baltic Sea. Denitrification rates were similar in both environments, despite lower nitrate and carbon concentrations in the offshore archipelago. However, DNRA (dissimilatory nitrate reduction to ammonium) rates were higher at the offshore archipelago stations, with a higher proportion of autochthonous carbon. Th…

Fragmentations and reactions of protonated O,O-dimethyl ethylphosphonate and some isotopomers produced by electrospray ionisation in an ion trap mass…

2008

Abstract The fragmentation behaviour of protonated O , O -dimethyl ethylphosphonate and its isotopomers deuterated in the α- and β-positions of the ethyl group and their fragment ions, particulary EtP(O)OMe + ( IV ), have been investigated both experimentally in an ion trap mass spectrometer and theoretically by electronic structure calculations at the B3LYP level. Of particular interest is the finding that the phosphonium ion IV eliminates ethene with hydrogen/deuterium loss from both the α-and β-positions. The initial step for both routes involves ethyl migration from P to O to form the ion MeOP + OEt which then loses ethene by two mechanisms, both of which lead to the same products. That…

Evaluation of a novel monoclonal antibody against tumor-associated MUC1 for diagnosis and prognosis of breast cancer

2019

There is still a great unmet medical need concerning diagnosis and treatment of breast cancer which could be addressed by utilizing specific molecular targets. Tumor-associated MUC1 is expressed on over 90 % of all breast cancer entities and differs strongly from its physiological form on epithelial cells, therefore presenting a unique target for breast cancer diagnosis and antibody-mediated immune therapy. Utilizing an anti-tumor vaccine based on a synthetically prepared glycopeptide, we generated a monoclonal antibody (mAb) GGSK-1/30, selectively recognizing human tumor-associated MUC1. This antibody targets exclusively tumor-associated MUC1 in the absence of any binding to MUC1 on health…