Formation and growth of lithium phosphate chemical gardens

We show that a chemical garden can be developed from an alkaline metal precipitate using a flow-driven setup. By injecting sodium phosphate solution into lithium chloride solution from below, a liquid jet appears, on which a precipitate grows forming a structure resembling a hydrothermal vent. The precipitate column continuously builds upward until a maximum height is reached. The vertical growth then significantly slows down while the tube diameter still increases. The analysis of the growth profiles has revealed a linear dependence of volume growth rate on the injection rate, hence yielding a universal growth profile. The expansion in diameter, localized at the tip of the structure, scales with a power law suggesting that the phenomenon is controlled by both diffusion and convection

From Balloon to Crystalline Structure in the Calcium Phosphate Flow-Driven Chemical Garden

We have studied the calcium phosphate precipitation reaction by producing chemical gardens in a controlled manner using a three-dimensional flow-driven technique. The injection of the phosphate containing solution into the calcium ion reservoir has resulted in structures varying from membranes to crystals. Dynamical phase diagrams are constructed by varying chemical composition and flow rates from which three different growth mechanisms have been revealed. The microstructural analysis by scanning electron microscopy and powder X-ray diffraction confirmed the morpho-logical transition from membrane tubes to crystalline branches upon decreasing pH

Dynamics of hydroxide-ion-driven reversible autocatalytic networks

An autocatalytic reaction network is designed utilising the interplay of hydroxide concentration dependent reactions and acid–base equilibria of imine hydrolysis

Autonóm földi, légi és vízi robotok korszerű irányításelmélete és mesterséges intelligencia eszközei = Advanced Control Theory and Artificial Intelligence Techniques of Autonomous Ground, Aerial, and Marine Robots

Módszereket dolgoztunk ki autonóm földi, légi és vízi járművek (robotok) egységes elveken alapuló modellezésére. Algoritmusokat fejlesztettünk ki járművek és formációban haladó járműegyüttesek stabil irányítására. Módszereket dolgoztunk ki nemsima nemlinearitásokat tartalmazó robotok és más mechanikai rendszerek modellezésére, identifikációjára és robusztus irányítására. Mozgástervezési és koordinálási algoritmusokat fejlesztettünk ki multiágensű rendszerek számára korlátozások jelenlétében a játékelmélet, a megerősítéses tanulás és a számítási intelligencia bevonásával. Modellezési eljárást és irányítási algoritmusokat dolgoztunk ki alulaktuált földi járművek és más mechanikai rendszerek számára lineáris korlátozások esetén. Megmutattuk, hogy időskálázással bővíthető a linearizálható dinamikus rendszerek osztálya. Algoritmust adtunk aktív alsó végtagprotézis szabályozására. Hiperredundáns robotok mozgástervezésére új elvű eljárást fejlesztettünk ki. Mozgásanalízisen és sztereótechnikán alapuló módszereket fejlesztettünk ki általános képfeldolgozási feladatok megoldására és beltéri járművek térbeli pozíciójának és orientációjának meghatározására valós időben. Új módszertant dolgoztunk ki diszkrét eseményű rendszerek többszintű modellezésére és felügyeleti irányítására. Módszert dolgoztunk ki navigációs szenzorok fúziójára és az állapotváltozók nagy pontosságú becslésére. Mintarendszert fejlesztettünk beltéri helikopterek irányítási algoritmusainak valós idejű vizsgálatára. | Methods were elaborated for modeling autonomous ground, aerial and marine vehicles (robots) based on uniform concepts. Algorithms were developed for stable control of vehicles and their ensembles moving in formation. For robots and other mechanical systems containing nonsmooth nonlinearities new methods were elaborated for modeling, identification and robust control. Motion design and coordination algorithms were developed for constrained multiagent systems based on game theory, reinforcement learning and computational intellegence. Modeling methods and control algorithms were elaborated for underactuated ground vehicles and other mechatronic systems under linear constraints. It was shown that using timescaling the class of linearizable dynamic systems can be extended. An algorithm was developed for the control of an active lower limb prosthetic. A novel method was elaborated for the motion design of hyperredundant robots. Methods based on motion analysis and stereo technique were developed for solving general image processing tasks and determining the position and orientation of indoor vehicles in real time. For discrete event systems a new methodology was given for the multilevel modeling and supervisory control. Methods were elaborated for the fusion of navigation sensors and the high-precision state estimation. A system of 3 indoor helicopters were developed for the investigation of control algorithms in real time

PPIs Are Not Responsible for Elevating Cardiovascular Risk in Patients on Clopidogrel—A Systematic Review and Meta-Analysis

Background: Clopidogrel and proton pump inhibitors (PPIs) are metabolized by cytochrome P450 enzymes. Contradictory results have been reported on possible complications of simultaneous PPI and clopidogrel use. Our aim was to investigate the clinical relevance of this debate with a systematic review and meta-analysis.Methods: The PubMed, Embase, and Cochrane Central Register of Controlled Trials electronic databases were searched for human studies [randomized controlled trials (RCTs) and observational studies] using the PICO format (P: patients on clopidogrel; I: patients treated with PPI; C: patients without PPI treatment; O: cardiovascular risk). We screened eligible studies from 2009 to 2016. After study exclusions, we extracted data from 27 articles for three outcomes: major adverse cardiac event (MACE), myocardial infarction (MI) and cardiovascular (CV) death. The meta-analysis was registered on PROSPERO (CRD42017054316).Results: Data were extracted on 156,823 patients from the 27 trials included (MACE: 23, CV death: 10, MI: 14). The risks of MACE (RR = 1.22, 95% CI = 1.06–1.396, p = 0.004) and MI (RR = 1.43, 95% CI = 1.24–1.66, p < 0.001) were significantly higher in the PPI plus clopidogrel group. However, subgroup analysis demonstrated that this significance disappeared in RCTs (RR = 0.99, 95% CI = 0.76–1.28, p = 0.93) in the MACE outcome group. There was no effect of combined PPI and clopidogrel therapy on CV death outcome (RR = 1.21, 95% CI = 0.97–1.50, p = 0.09).Conclusion: Concomitant use of PPIs and clopidogrel has been proved not to be associated with elevated cardiovascular risks according to RCTs. Based on our results, no restrictions should be applied whenever PPIs and clopidogrel are administered simultaneously

Palynomorphs of the Normapolles group and related plant mesofossils from the Iharkút vertebrate site, Bakony Mountains (Hungary)

Abstract Palynological and paleobotanical investigation of bonebeds and other strata of the Csehbánya Formation from the vertebrate locality at Iharkút (Bakony Mts, Hungary) reveals well-preserved Santonian palynological assemblages dominated by the Normapolles group, with a minor component consisting of other angiosperm pollen, some gymnosperm pollen, and spores. Eleven species of Normapolles-type pollen grains belonging to seven genera and fruit remains of a new taxon, Sphaeracostata barbackae gen. et sp. nov., are described. The new species is very abundant in the material, represented by ca. 1000 specimens. The genus Caryanthus Friis and an unnamed form previously reported from Haţeg by Lindfors et al. (2010) are also present. Plants producing Normapolles-type pollen grains diversified during the Late Cretaceous, with a bloom in the Santonian. The palynostratigraphy of the Upper Cretaceous terrestrial sediments in the studied region is based on Normapolles-related species. The studied assemblage is assigned to the Oculopollis zaklinskaiae-Tetracolporopollenites (Brecolpites) globosus Zone (or Zone C) indicating a late Santonian age. Comparison of the Iharkút palynoflora with other known Upper Cretaceous palynofloras of Central Europe shows diachronous occurrence of Normapolles taxa at different geographic localities and warrants further investigation. The ecological requirements of the amphibian fauna reflect azonal conditions controlled by the availability of water, which is in agreement with the inferred ecological conditions based on the paleobotanical investigations. The fauna is of entirely non-marine character, further supported by isotope studies, in line with our data showing that the palynological samples contain no marine forms

Effects of radial injection and solution thickness on the dynamics of confined A plus B -> C chemical fronts

The spatio-temporal dynamics of an A + B -> C front subjected to radial advection is investigated experimentally in a thin solution layer confined between two horizontal plates by radially injecting a solution of potassium thiocyanate (A) into a solution of iron(iii) nitrate (B). The total amount and spatial distribution of the product FeSCN2+ (C) are measured for various flow rates Q and solution thicknesses h. The long-time evolution of the total amount of product, n(C), is compared to a scaling obtained theoretically from a one-dimensional reaction-diffusion-advection model with passive advection along the radial coordinate r. We show that, in the experiments, n(C) is significantly affected when varying either Q or h but scales as n(C) similar to Q(-1/2)V where V is the volume of injected reactant A provided the solution thickness h between the two confining plates is sufficiently small, in agreement with the theoretical prediction. Our experimental results also evidence that the temporal evolution of the width of the product zone, W-C, follows a power law, the exponent of which varies with both Q and h, in disagreement with the one-dimensional model that predicts W-C similar to t(1/2). We show that this experimental observation can be rationalized by taking into account the non-uniform profile of the velocity field of the injected reactant within the cell gap