Accurate modeling of the dynamics of dissociative chemisorption on metal surfaces

Fundamental understanding of molecular reactions on metal surfaces is important for improving heterogeneous catalysis. Therefore, the reaction of small molecules on well-defined metal surfaces is investigated with state-of-the-art DFT calculations. Efforts are made to improve the agreement between experiment and theory by employing density functionals belonging to a higher level of theory than typically used. Furthermore, molecular dynamics are performed both with ab initio calculations and precomputed potential energy surfaces to investigate reaction mechanisms. This way dynamical aspects of reaction mechanisms can be investigated, e.g., the effect of rovibrational excitation of a molecule on the reaction probability and mechanism.NWO TOP grant no. 715.017.00

Secondary vestibulocerebellar projections to the flocculus and uvulo-nodular lobule of the rabbit: a study using HRP and double fluorescent tracer techniques

The distribution of vestibular neurons projecting to the flocculus and the nodulus and uvula of the caudal vermis (Larsell's lobules X and IX) was investigated with retrograde axonal transport of horseradish peroxidase and the fluorescent tracers Fast Blue, Nuclear Yellow and Diamidino Yellow. The presence of collateral axons innervating the flocculus on one hand and the nodulus and uvula on the other was studied with simultaneous injection of the different fluorescent tracers. The distribution of vestibular neurons projecting to either flocculus or caudal vermis is rather similar and has a bilateral symmetry. The projection from the magnocellular medial vestibular nucleus is very sparse, while that from the lateral vestibular nucleus is absent. The majority of labeled neurons was found in the medial, superior, and descending vestibular nuclei, in that order. Double labeled neurons were distributed in a similar way as the single labeled ones. Labeled neurons project to the nodulus and uvula, the flocculus, and to both parts of the cerebellum simultaneously in a ratio of 12:4:1. Five different populations of vestibulocerebellar neurons can be distinguished on the basis of their projection to the: (1) ipsilateral flocculus, (2) contralateral flocculus, (3) ipsilateral flocculus and nodulus/uvula, (4) contralateral flocculus and nodulus/uvula, and (5) nodulus/uvula

Organizing interfaces between government institutions and interactive governance

Initiatives to encourage the involvement of citizens and NGOs in decision-making can be seen in a wide variety of countries. Interactive policy-making, citizen panels, citizen charters, new forms of participation and other forms are being used to increase the influence of citizens on decision-making. An important issue in scientific debate is the relationship between citizen participation and existing democratic institutions. The main question for this article therefore is: what are the possibilities and difficulties in creating interconnections between interactive governance and existing democratic institutions? We have conducted an action research project to organize this interconnection between an interactive governance project (Around Arnemuiden, Living with Water) and existing democratic institutions. We describe and evaluate the interface arrangements we created: political, executive, professional, and policy interface. The executive, professional, and policy interfaces turned out to be weak or moderate, while the political interfaces was strong. Executives and professionals are reluctant to actively involve and commit to interactive processes. The organization of the interconnection between interactive processes and existing representative democratic institutions is very difficult and needs constant maintenance

Curious mechanism of the dissociative chemisorption of ammonia on Ru(0001)

Theoretical Chemistr

An AIMD study of dissociative chemisorption of methanol on Cu(111) with implications for formaldehyde formation

An important industrial process is methanol steam reforming, which is typically used in conjunction with copper catalysts. However, little agreement exists on the reaction mechanisms involved on a copper catalyst. Therefore, we have performed research yielding additional insight into the reaction mechanism for dissociative chemisorption of methanol on Cu(111) using ab initio molecular dynamics, supported by static calculations of the molecule-surface interaction with density functional theory. Our work predicts that after the initial dissociation, formaldehyde is formed through three different mechanisms. Additionally, it is observed that at high energy, CH cleavage is the dominant pathway instead of the formerly presumed OH cleavage pathway. Finally, in order to describe the interaction of methanol with the metal surface, the SRP32-vdW functional is used, which has been previously developed and tested for CHD3 on Ni(111), Pt(111), and Pt(211) using the Specific Reaction Parameter (SRP) approach. In this work, the SRP32-vdW functional is applied to methanol on Cu(111) as well, in the hope that future experiments can validate the transferability of the SRP32-vdW functional to chemically related molecule-metal surface systems.Theoretical Chemistr

Unjuk Kerja Pompa Air Shimizu Type Ps-128 Bit Yang Difungsikan Sebagai Turbin Air

Utilization of water pump Shimizu Type PS-128 Bit which functioned as a water turbine for Micro Hydro Power Plant (MHPP) is an effort in the search for alternative energy in a simple and easy in term of manufacturing and assembling. Principally, the water pump is used to suck the water from a lower surface and raise it to a certain height. The basic of working of a pump is the opposite of a water turbine, and therefore can function as reaction water turbine, in which water from a certain height rotate the pump impeller.Testing the water pump Shimizu Type PS-128 Bit as a water turbine is carried out in the Laboratory of Mechanical Engineering University of Sam Ratulangi. The “reaction turbine” is driven by four water pumps which connected in series and parallel. It aims to get different heights (head) and flow rate (Q).Flow rate and the load on the dynamometer (W1) has been determined, as the lowest round “reaction turbine” that is charged with the force (N) certain turbine cannot rotate. So that initial water discharge is determined by Q = 31 liters/minute. Based on the research that has been done that the power generated depends on the rotation, H and Q. The maximum power generated Pm = 12 watt is at Q = 37 liters/minute, H = 18 m, and n = 1080 rpm

Does Colour Filling-In Account for Colour Perception in Natural Images?

It is popular to attribute the appearance of extended colour fields to a process of filling-in from the differential colour signals at colour edges, where one colour transitions to another. We ask whether such a process can account for the appearance of extended colour fields in natural images. Some form of colour filling-in must underlie the equiluminant colour Craik-O’Brien-Cornsweet effect and the Water colour Effect, but these effects are too weak to account for the appearance of extended colour fields in natural images. Moreover, the graded colour disappearance effect reported as evidence for colour filling-in does not work under natural viewing conditions. We demonstrate that natural images do not look very colourful when their colour is restricted to edge transitions . Moreover, purely chromatic images with maximally graded (‘edgeless’) transitions look fully colourful. Consequently, we conclude that colour filling-in makes no more than a minor contribution to the appearance of extended colour regions in natural images

Detection-Loophole-Free Test of Quantum Nonlocality, and Applications

We present a source of entangled photons that violates a Bell inequality free of the "fair-sampling" assumption, by over 7 standard deviations. This violation is the first experiment with photons to close the detection loophole, and we demonstrate enough "efficiency" overhead to eventually perform a fully loophole-free test of local realism. The entanglement quality is verified by maximally violating additional Bell tests, testing the upper limit of quantum correlations. Finally, we use the source to generate secure private quantum random numbers at rates over 4 orders of magnitude beyond previous experiments.Comment: Main text: 5 pages, 2 figures, 1 table. Supplementary Information: 7 pages, 2 figure

Dynamical Study of the Dissociative Chemisorption of CHD3 on Pd(111)

The specific reaction parameter (SRP) approach to density functional theory has been shown to model reactions of polyatomic molecules with metal surfaces important for heterogeneous catalysis in the industry with chemical accuracy. However, transferability of the SRP functional among systems in which methane interacts with group 10 metals remains unclear for methane + Pd(111). Therefore, in this work, predictions have been made for the reaction of CHD3 on Pd(111) using Born–Oppenheimer molecular dynamics while also performing a rough comparison with experimental data for CH4 + Pd(111) obtained for lower incidence energies. Hopefully, future experiments can test the transferability of the SRP functional among group 10 metals also for Pd(111). We found that the reactivity of CHD3 on Pd(111) is intermediate between and similar to either Pt(111) or Ni(111), depending on the incidence energy and the initial vibrational state distribution. This is surprising because the barrier height and experiments performed at lower incidence energies than investigated here suggest that the reactivity of Pd(111) should be similar to that of Pt(111) only. The relative decrease in the reactivity of Pd(111) at high incidence energies is attributed to site specificity of the reaction and to dynamical effects such as the bobsled effect and energy transfer from methane to the surface.Theoretical Chemistr