Origin Of Synergy Research Articles

Universal Piezo-Photocatalytic Wastewater Treatment on Realistic Pollutant Feedstocks by Bi4TaO8Cl: Origin of High Efficiency and Adjustable Synergy.

Clean water is a fundamental human right but millions struggle for it daily. Herein, we demonstrate a new piezo-photocatalyst with immense structural diversity for universal wastewater decontamination. Single-crystalline Bi4TaO8Cl nanoplates with exposed piezoelectric facets exhibit visible-light response, piezoelectric behavior with coercive voltages of ±5 V yielding 0.35% crystal deformation, and pressure-induced band-bending of >2.5 eV. Using five common contaminants of textile and pharmaceutical industries, we show that the nanoplates can mineralize them in all piezocatalytic, photocatalytic, and piezo-photocatalytic approaches with efficiencies higher than most catalysts developed for just one contaminant. Their efficiencies for feedstocks differing over 2 orders of magnitude in concentrations, the highest to date, are also demonstrated to simulate real-life situations. These extensive studies established that combining piezocatalytic and photocatalytic approaches can lead to a tremendous synergy exceeding >45%. The origin of synergy has been illustrated for the first time using band-bending models and improved charge transfer from valence and conduction band electronic surfaces. We further quantified synergy across reactants, concentrations, and ultrasonic frequency and power to demonstrate their versatility and unpredictability. Finally, seven parameters that contribute to synergy but create unpredictability have been identified for the rational design of piezo-photocatalysts for wastewater treatment.

Interplay of synergy and redundancy in diamond motif.

The formalism of partial information decomposition provides a number of independent components which altogether constitute the total information provided by the source variable(s) about the target variable(s). These non-overlapping terms are recognized as unique information, synergistic information, and redundant information. The metric of net synergy conceived as the difference between synergistic and redundant information is capable of detecting effective synergy, effective redundancy, and information independence among stochastic variables. The net synergy can be quantified using appropriate combinations of different Shannon mutual information terms. The utilization of the net synergy in network motifs with the nodes representing different biochemical species, involved in information sharing, uncovers rich store for exciting results. In the current study, we use this formalism to obtain a comprehensive understanding of the relative information processing mechanism in a diamond motif and two of its sub-motifs, namely, bifurcation and integration motif embedded within the diamond motif. The emerging patterns of effective synergy and effective redundancy and their contribution toward ensuring high fidelity information transmission are duly compared in the sub-motifs. Investigation on the metric of net synergy in independent bifurcation and integration motifs are also executed. In all of these computations, the crucial roles played by various systemic time scales, activation coefficients, and signal integration mechanisms at the output of the network topologies are especially emphasized. Following this plan of action, we become confident that the origin of effective synergy and effective redundancy can be architecturally justified by decomposing a diamond motif into bifurcation and integration motif. According to our conjecture, the presence of a common source of fluctuations creates effective redundancy. Our calculations reveal that effective redundancy empowers signal fidelity. Moreover, to achieve this, input signaling species avoids strong interaction with downstream intermediates. This strategy is capable of making the diamond motif noise-tolerant. Apart from the topological features, our study also puts forward the active contribution of additive and multiplicative signal integration mechanisms to nurture effective redundancy and effective synergy.

Synergism in a HDEHP/TOPO Liquid-Liquid Extraction System: An Intrinsic Ligands Property?

Among the proposed mechanisms to predict and understand synergism in solvent extraction, the possibility of a preorganization of the mixture of extractant molecules has never been considered. Whether involving synergistic aggregation as for solubilization enhancement with reverse micelles or favored molecular interaction between the extractant molecules, evaluation of this hypothesis requires characterization of the aggregates formed by the extractant molecules at different scales. We investigate here the HDEHP/TOPO couple of extractant with methods ranging from vibrational spectroscopy and ESI-MS spectrometry to vapor pressure osmometry and neutron and X-ray scattering to cover both molecular and supramolecular scales. These experimental methods are subjected to DFT calculations and molecular dynamics calculations, allowing a rationalization of the results through the different scales. Performed in the absence of any cation, this original study allows a decorrelation of the mechanisms at the origin of synergy: it appears that no clear preorganization of the extractants can explain the synergy and therefore that the synergistic aggregation observed in the presence of cations is rather due to the chelation mechanisms than to intrinsic properties of the extractant molecules.

New technical challenges and recent advances in hydrotreatment catalysis. A critical updating review

The petroleum industry gets confronted with more stringent requirements with respect to transportation fuels: diminution by a factor of 10, or more, of the sulphur content, and a drastic diminution of the aromatic content. Besides, the quality of the crude oil supply keeps diminishing on an average. For this, the hydrotreating processes (HDS, HDN, HDM, hydrogenation, hydrocracking) will occupy a still increasing place in the refining processes. In a first part, we shall select some of the most important results published recently: use of new modifiers and supports (TiO2, ZrO2, mixed oxides), of metals not yet used in hydrotreating (Ru, Rh, Pd, Pt, possibly Nb, associations RuU, PdU, VU etc.), confirmation of the existence of distinct catalytic sites (hydrogenation and hydrogenolysis of the heteroatom-carbon bonds). Other new results should contribute to clarify the controversies and uncertainties concerning the origin of synergy between different elements and the changes of selectivity as a function of the experimental conditions. For this last topic, reference shall be made to the CoMoS model and the remote control theory. In a second part, we shall summarise the new constraints that the hydrotreating processes will face. It will be necessary to save still more energy. It will also be necessary to achieve a better balance of the various reactions taking place in a given process. The overall selectivity of catalysts and processes will have to be improved. In the third part, we shall try to emphasize directions of research which could help reach the objectives. We shall shortly outline the future contributions of chemical engineering. We shall examine with more details the problems concerning the genesis of adequate catalytic sites (underlining the enormous influence of the activation steps) and the modification of activity by means of the composition of the reacting medium. As the problem of synergy remains crucial for the future developments, we shall also present results with new synergetic systems (WS2 + supported Rh or Pd; MoS2 + supported Pt). The new results give hope that the mechanisms of synergy could get clarified in the near future.