In this demonstration, we present a system that automates regression testing for video games using automated planning techniques. Traditional test scripts are a common method for testing both video games and software in general. While effective, they require manual creation and frequent updates throughout development, making the process labor-intensive. Our system eliminates this burden by automatically generating and maintaining test scripts. The test engineer only needs to define the game's rules using the Planning Domain Definition Language (PDDL) and specify initial states and goals for individual test cases. This significantly reduces human effort while ensuring test scripts remain up to date. Additionally, our system integrates with game engine editors- supporting both Unity and Unreal to execute and evaluate test cases directly within the game. It collects detailed logs, telemetry data, and video recordings, allowing users to review test results efficiently.

The global food delivery market provides many opportunities for AI-based services that can improve the efficiency of feeding the world. This paper presents the Cloud Kitchen platform as a decision-making tool for restaurants with food delivery and a simulator to evaluate the impact of the decisions. The platform contains a Technology-Specific Bridge (TSB) that provides an interface for communicating with restaurants or the simulator. TSB uses a planning domain model to represent decisions embedded in the Unified Planning Framework (UPF). Decision-making, which concerns allocating customers' orders to vehicles and deciding in which order the customers will be served (for each vehicle), is done via a Vehicle Routing Problem with Time Windows (VRPTW), an efficient tool for this problem. We show that decisions made by our platform can improve customer satisfaction by reducing the number of delayed deliveries using a real-world historical dataset.

Previous STRIPS domain model acquisition approaches that learn from state traces start with the names and parameters of the actions to be learned. Therefore their only task is to deduce the preconditions and effects of the given actions. In this work, we explore learning in situations when the parameters of learned actions are not provided. We define two levels of trace quality based on which information is provided and present an algorithm for each. In one level (L1), the states in the traces are labeled with action names, so we can deduce the number and names of the actions, but we still need to work out the number and types of parameters. In the other level (L2), the states are additionally labeled with objects that constitute the parameters of the corresponding grounded actions. Here we still need to deduce the types of the parameters in the learned actions. We experimentally evaluate the proposed algorithms and compare them with the state-of-the-art learning tool FAMA on a large collection of IPC benchmarks. The evaluation shows that our new algorithms are faster, can handle larger inputs and provide better results in terms of learning action models more similar to reference models.

In this paper, we propose a method and workflow for automating regression testing of certain video game aspects using automated planning and incremental action model learning techniques. The basic idea is to use detailed game logs and incremental action model learning techniques to maintain a formal model in the planning domain description language (PDDL) of the gameplay mechanics. The workflow enables efficient cooperation of game developers without any experience with PDDL or other formal systems and a person experienced with PDDL modeling but no game development skills. We describe the method and workflow in general and then demonstrate it on a concrete proof-of-concept example – a simple role-playing game provided as one of the tutorial projects in the popular game development engine Unity. This paper presents the first step towards minimizing or even eliminating the need for a modeling expert in the workflow, thus making automated planning accessible to a broader audience.

Previous STRIPS domain model acquisition approaches that learn from state traces start with the names and parameters of the actions to be learned. Therefore their only task is to deduce the preconditions and effects of the given actions. In this work, we explore learning in situations when the parameters of learned actions are not provided. We define two levels of trace quality based on which information is provided and present an algorithm for each. In one level (L1), the states in the traces are labeled with action names, so we can deduce the number and names of the actions, but we still need to work out the number and types of parameters. In the other level (L2), the states are additionally labeled with objects that constitute the parameters of the corresponding grounded actions. Here we still need to deduce the types of the parameters in the learned actions. We experimentally evaluate the proposed algorithms and compare them with the state-of-the-art learning tool FAMA on a large collection of IPC benchmarks. The evaluation shows that our new algorithms are faster, can handle larger inputs and provide better results in terms of learning action models more similar to reference models.

Single-atom catalysts represent an essential and ever-growing family of heterogeneous catalysts. Recent studies indicate that besides the valuable catalytic properties provided by single-atom active sites, the presence of single-atom sites on the catalyst substrates may significantly influence the population of supported metal nanoparticles coexisting with metal single atoms. Treatment of ceria-based single-atom catalysts in oxidizing or reducing atmospheres was proven to provide precise experimental control of the size of the supported Pt nanoparticles, and, correspondingly, control of catalyst activity and stability. Based on dedicated surface science experiments, ab-initio calculations and kinetic Monte-Carlo simulations we demonstrate that the morphology of Pt nanoparticle population on ceria surface is a result of a competition for Pt atoms between Pt single-atom sites and Pt nanoparticles. In oxidizing atmosphere, Pt single-atom sites provide strong bonding to single Pt atoms and Pt nanoparticles shrink. In reducing atmosphere, Pt single atom sites are depopulated and Pt nanoparticles grow. We formulate a generic model of Pt redispersion and coarsening on ceria substrates. Our model provides a unified atomic-level explanation for a variety of metal nanoparticle dynamic processes observed in single-atom catalysts under stationary or alternating oxidizing/reducing atmospheres, and allows to classify the conditions when nanoparticle ensembles on single-atom catalysts substrates can be stabilized against Ostwald ripening.

Iron (III) oxide, in the form of hematite (α-Fe2O3), is a n-type semiconductor which is photoactive in the visible spectral region. Therefore, use in photoelectrocatalysis and photoassisted water electrolysis may be suggested. For such implementations, stability of contacts with liquid phases is mandatory. Hematite is stable in alkaline media but less stable in acidic media. For the first time the coverage of porous photoactive Sn doped hematite by thin capping layers of TiO2, deposited by Atomic Layer Deposition (ALD) and its impact on photocurrent and chemical stability of hematite is shown. The nominal thicknesses of the TiO2 ALD coatings were 0.5, 2 and 7.5 nm. The presence of the TiO2 coatings was evidenced by X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy (HR-TEM) and scanning TEM coupled with energy dispersive X-ray (EDX) spectroscopy. HR-TEM analyses revealed that the TiO2 capping layers were amorphous and conformal. Exposure of uncovered hematite layers to 1 M sulfuric acid led to a nominal dissolution rate of 0.23 nm/h which was halved when a TiO2 ALD coating (7.5 nm thin) was applied. Due to mismatch of the valence band positions of the two semiconductors, photocurrents were strongly diminished as the capping layer thickness was increased. Post-calcination of as deposited ALD films on hematite resulted in an increase of photocurrent, which only exceeded photocurrents of pristine hematite when the ALD thickness was not more than 0.5 nm.

Among the emerging 2D materials, transition metal chalcogenides are particularly encouraging as alternative semiconducting graphene-like nanomaterial. Recently, 2D MoSe2 has been gaining interest due to its intriguing properties, in many ways exceeding those of the extensively studied MoS2. The deposition of 2D nanomaterials in a conformal and uniform fashion on complex-shaped nanostructures is highly appealing but only achievable by atomic layer deposition (ALD). Unfortunately, the synthesis of MoSe2 by ALD is hindered by a current substantial lack of feasible Se precursors. In this work, we synthesized a set of alkysilyl (R3Si)(2)Se and alkylstannyl (R3Sn)(2)Se compounds and studied their suitability as Se ALD precursors. Thus, ALD processes carried out using MoCl5 as Mo precursor counterpart were followed by an extensive characterization of the as deposited material. The corresponding results revealed successful deposition of MoSe2 nanostructures on substrates of different nature with dominant out-of-plane orientation. Eventually, the growth evolution of the MoSe2 during the very early ALD stage was studied and described, displaying concomitant in-plane and out-of-plane MoSe2 growth. All in all, a set of suitable Se precursors presented herein paves the way for the deposition of 2D MoSe2 with all the own ALD benefits and allow the further study of its promising properties in a wide number of applications. (C) 2020 Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).

This paper presents an effective hydrothermal route to decorate various types of anodic 1D TiO2 nanotubes (TiO2 NTs) with magnetite nanoparticles (Fe3O4 NPs), yielding a magnetically guidable and active photocatalyst. A unique portfolio of TiO2 NTs including single-tube, single-walled, and double-walled ones was used. Optimal conditions for uniform decoration of these nanotubes by Fe3O4 NPs (two different loadings) using a wet chemical synthesis based on an oleate hydrothermal approach were found. The resulting TiO2NTs@Fe(3)O(4)NPs were shown to be superparamagnetic at room temperature, to have a stable connection of NPs to NTs, and to have good magnetic response under an external applied magnetic field. The as-prepared materials were used as magnetically guidable photocatalyst for the decomposition of a model dye (methylene blue). Fe3O4 NPs enhanced the photocatalytic activity of TiO2 NTs under visible light. In principle, TiO2NTs@Fe(3)O(4)NPs could be used as magnetically guidable drug delivery system with photoinduced drug release.

Heterojunctions between high-work-function metals and metal oxides typically lead to Schottky-type transport barriers resulting from charge transfer between the neighboring materials. These yield versatile electronic functionality exploited for current rectification, memristive behavior, or photocatalysis. Height, width, and shape of the interfacial transport barrier are strongly affected by charge screening via ionic defects, which are often extremely difficult to probe. The ionic nature of a variable contact resistance in heterojunctions between Nb-doped SrTiO3 (Nb:SrTiO3) and platinum is explored. A control of cationic vacancy defects at the interface is achieved by different annealing procedures in oxidizing and reducing conditions before establishing Pt/Nb:SrTiO3 heterojunctions. Detailed analysis of electronic transport across the heterojunctions reveal significantly varied transport barriers resulting from the cationic defect structure at the interface. These findings are supported by conductive-tip atomic force microscopy and in situ photoemission spectroscopy showing diminished conductivity of the Nb:SrTiO3 surface and the formation of an insulating surface skin layer after oxygenation. At high doping level, oxygen stoichiometry cannot explain the observed behavior. The increased transport barrier height is therefore linked to strontium vacancy defects. The tailored cation disorder yields access to the ionic control of electronic transport in functional oxide heterojunctions.

High-power impulse magnetron sputtering of a Ta target in precisely controlled Ar+O2+N2 gas mixtures was used to prepare amorphous N-rich tantalum oxynitride (Ta–O–N) films with a finely varied elemental composition. Postdeposition annealing of the films at 900°C for 5 min in vacuum led to their crystallization without any significant change in the elemental composition. The authors show that this approach allows preparation of a Ta–O–N film with a dominant Ta2N2O phase of the bixbyite structure. As far as the authors know, this phase has been neither experimentally nor theoretically reported yet. The film exhibits semiconducting properties characterized by two electrical (indirect or selection-rule forbidden) bandgaps of about 0.2 and 1.0 eV and one optical (direct and selection-rule allowed) bandgap of 2.0 eV (suitable for visible-light absorption up to 620 nm). This observation is in good agreement with the carried out ab initio calculations and the experimental data obtained by soft and hard X-ray photoelectron spectroscopy. Furthermore, the optical bandgap is appropriately positioned with respect to the redox potentials for water splitting, which makes this material an interesting candidate for this application.

Inverse model catalysts represent valuable systems for studying metal-oxide interactions and finite size effects in heterogeneous catalysis. To maximize the potential of model catalytic studies, high level of control over model catalyst properties is desirable. Here we introduce experimental approaches for obtaining inverse ceria/copper model catalysts of well-defined crystallographic phases CeO2, iota-Ce7O12, CeO1.67, and c-Ce2O3 supported on Cu (1 1 1). The presented cerium oxide thin films are ultrathin (2 monolayers), discontinuous, and feature highly defined stoichiometry and crystallographic structure with characteristic (1x1), (root 7x root 7) R19 degrees, (3x3), or (4x4) electron diffraction patterns. Compared to thicker films and bulk ceria, the prepared ultrathin cerium oxides exhibit a distinctly different dependence of the lattice constant on the stoichiometry, and show activation barrier preventing their complete oxidation. These phenomena illustrate that metal-oxide interactions and finite size effects strongly influence the behavior of the presented inverse model catalysts indicating their prospective use in disentangling complex functionalities of ceria/copper catalytic systems.

Glassy carbon (GC) is one of the most often used carbon materials in laboratory practice. Despite the fact that its electrocatalytic properties are largely surface-state dependent, a standardised procedure for its activation is lacking. This work presents a detailed, systematic investigation of aGC electrode pre-treatment based on potential cycling in a strongly alkaline environment within optimised potential limits. The surface composition was followed by X-ray photoelectron spectroscopy. This allowed determination of the overall elemental surface composition as well as identification of important surface functional groups. Electro-catalytic activity of the activated electrodes was tested by using Fe3+/2+, Fe(CN)(6)(3-/4-) and benzoquinone/hydroquinone couples. A combination of spectroscopic and electrochemical information made it possible to establish a correlation between the electrode's electrocatalytic activity and its surface composition and to identify optimal activation conditions which resulted in a highly active, reproducible and stable electrode surface. It can be concluded that, due to its relative simplicity and efficiency, the present method has the potential to become a standard procedure of GC electrode activation. (C) 2019 Elsevier Ltd. All rights reserved.

Iridium-based materials are among the most active bifunctional catalysts in heterogeneous catalysis and electrocatalysis. We have investigated the properties of atomically defined Ir/CeO2(111) model systems supported on Cu(111) and Ru(0001) by means of synchrotron radiation photoelectron spectroscopy, resonant photoemission spectroscopy, near ambient pressure X-ray photoelectron spectroscopy (NAP XPS), scanning tunneling microscopy, and temperature programmed desorption. Electronic metal-support interactions in the Ir/CeO2(111) system are accompanied by charge transfer and partial reduction of CeO2(111). The magnitude of the charge transfer depends strongly on the Ir coverage. The Ir/CeO2(111) system is stable against sintering upon annealing to 600 K in ultrahigh vacuum (UHV). Annealing of Ir/CeO2(111) in UHV triggers the reverse oxygen spillover above 450 K. The interaction of hydrogen with Ir/CeO2(111) involves hydrogen spillover and reversible spillover between 100 and 400 K accompanied by the formation of water above 190 K. Formation of water coupled with the strong reduction of CeO2(111) represents the dominant reaction channel upon annealing in H2 above 450 K. The interaction of Ir/CeO2(111) with oxygen has been investigated at moderate and NAP conditions. Additionally, the formation and stability of iridium oxide prepared by deposition of Ir in oxygen atmosphere was investigated upon annealing in UHV and under exposure to H2. The oxidation of Ir nanoparticles under NAP conditions yields stable IrOx nanoparticles. The stability of Ir and IrOx nanoparticles under oxidizing conditions is hampered, however, by encapsulation by cerium oxide above 450 K and additionally by copper and ruthenium oxides under NAP conditions.

Atomic layer deposition (ALD) represents a unique deposition technique that allows to coat uniformly various high aspect ratio (HAR) porous nano structures, in addition to its traditional role to coat flat substrates (e.g. Si wafers). Self-organized anodic TiO2 nanotube (TNT) layers belong among the most investigated inorganic nano structures. They possess highly functional materials with promising application potential across many technological fields. Herein, we review the utilization of ALD for the functionalization of anodic TNT layers by secondary materials to advance their physicochemical and photoelectrochemical properties. First, the application of ALD for functionalization of porous aluminium oxide, which represent fundamental HAR nanostructure, is briefly introduced. Then the main experimental parameters governing the uniformity and the conformality of ALD coating within HAR nanostructures are discussed. Finally, the review focuses on the use of ALD to deposit secondary materials into TNT layers for various purposes - the introduction of pioneering studies is followed by particular examples of ALD based functionalizations of coated TNT layers for optimized visible-light absorption, charge separation and passivation, (photo)catalysis, stability, gas sensing, and energy storage. (C) 2018 The Authors. Published by Elsevier Ltd.

Smallest metallic (blue) and ionic (grey) Pt objects on ceria are shaped and controlled by surface oxygen content.

This study deals with the preparation and characterization of metallic nanoinclusions on the surface of semiconducting Bi2Se3 that could be used for an enhancement of the efficiency of thermoelectric materials. We used Au forming a 1D alloy through diffusion (point nanoinclusion) and Mo forming thermodynamically stable layered MoSe2 nanosheets through the reaction with the Bi2Se3. The Schottky barrier formed by the 1D and 2D nanoinclusions was characterized by means of atomic force microscopy (AFM). We used Kelvin probe force microscopy (KPFM) in ambient atmosphere at the nanoscale and compared the results to those of ultraviolet photoelectron spectroscopy (UPS) in UHV at the macroscale. The existence of the Schottky barrier was demonstrated at +120 meV for the Mo layer and -80 meV for the Au layer reflecting the formation of MoSe2 and Au/Bi2Se3 alloy, respectively. The results of both methods (KPFM and UPS) were in good agreement. We revealed that long-time exposure (tens of seconds) to the electrical field leads to deep oxidation and the formation of perturbations greater than 1 µm in height, which hinder the I-V measurements.

The present work presents a strategy to stabilize amorphous anodic self-organized TiO2 nanotube layers against morphological changes and crystallization upon extensive water soaking. The growth of needle-like nanoparticles was observed on the outer and inner walls of amorphous nanotube layers after extensive water soakings, in line with the literature on water annealing. In contrary, when TiO2 nanotube layers uniformly coated by thin TiO2 using atomic layer deposition (ALD) were soaked in water, the growth rates of needle-like nanoparticles were substantially reduced. We investigated the soaking effects of ALD TiO2 coatings with different thicknesses and deposition temperatures. Sufficiently thick TiO2 coatings (≈8.4 nm) deposited at different ALD process temperatures efficiently hamper the reactions between water and F− ions, maintain the amorphous state, and preserve the original tubular morphology. This work demonstrates the possibility of having robust amorphous 1D TiO2 nanotube layers that are very stable in water. This is very practical for diverse biomedical applications that are accompanied by extensive contact with an aqueous environment.

The success of graphene opened a door for a new class of chalcogenide materials with unique properties that can be applied in the semiconductor technology [1]. Monolayers of two-dimensional transition metal dichalcogenides (2D TMDCs) possess a direct band gap [2] that is crucial for optoelectronic applications. Additionally, the direct band gap can be easily tuned by either chemical composition or external stimuli. Next to the optoelectronic applications, where a monolayer planar structure is necessary to employ, a layer of standing flakes, which possesses a large surface area, can be used for hydrogen evolution [3] a photodegradation of organic dyes [4] or as electrodes in Li ion batteries [5]. In principle, TMDCs can be prepared by various top-down (e.g. exfoliation) and bottom-up techniques, such as chemical vapor deposition (CVD) and atomic layer deposition (ALD) growth techniques [1]. MoS2, a typical representative of TMDCs, has been widely studied for many applications. Recently, the possibility to employ ALD as a technique to grow MoS2 has been reported. In these works (CH3)2S2 [6] or H2S [7, 8] were used as the S precursor and Mo(CO)6 [6], MoCl5 [7] or Mo(thd)3 [8] as the Mo precursors. From the practical point of view, MoSe2 is even more interesting than MoS2 since MoSe2 possesses a higher electrical conductivity than MoS2 [9, 10]. Recently, we have shown that ALD deposition of MoSe2 [11] or Mo-O-Se [12] using ((CH3)3Si)2Se as the Se precursor and the MoCl5 or Mo(CO)6, respectively, as the Mo precursors is feasible. The presentation will focus on the synthesis of MoS2 and MoSe2 by ALD, their characterization and applications in various fields. Experimental details and some recent photocatalytic and hydrogen evolution results will be presented and discussed. References: [1] A. V. Kolobov, J. Tominaga, Two-Dimensional Transition-Metal, Dichalcogenides. Springer Series in Materials Science, Springer International Publishing AG, Switzerland 2016 [2] B. Radisavljevic, A. Radenovic, J. Brivio, V. Giacometti, A. Kis, Nat. Nanotechnol. 2011, 6, 147. [3] L. Wang, Z. Sofer, J. Luxa, M. Pumera, Adv. Mater. Interfaces 2015, 2, 1500041 [4] Y. Wu, M. Xu, X. Chen, S. Yang, H. Wu, J. Pan, X. Xiong, Nanoscale 2016, 8, 440 [5] D. Ilic, K. Wiesener, W. Schneider, H. Oppermann, G. Krabbes, J.Power Sources 1985, 14, 223 [6] Z. Jin, S.Shin,D.H.Kwon, S. J.Han,Y. S.Min,Nanoscale 2014, 6, 14453. [7] L. K. Tan, B. Liu, J. H. Teng, S. Guo, H. Y. Low, K. P. Loh, Nanoscale 2014, 6, 10584 [8] M. Mattinen et al., Adv. Mater. Interfaces 2017, 4, 1700123. [9] D. Kong, H. Wang, J. J. Cha, M. Pasta, K. J. Koski, J. Yao, Y. Cui, Nano Lett. 2013, 13, 1341. [10] A. Eftekhari, Appl. Mater. Today 2017, 8. [11] M. Krbal et al., Phys. Stat. Sol. RRL, 2018, 12, 1800023 [12] S. Ng et al., Adv. Mater. Interfaces 2017, 1701146.

Two-dimensional MoS2 nanostructures are highly interesting and effective in a number of energy-related applications. In this work, the synthesis of ultra-thin MoS2 nanosheets produced by the thermal Atomic Layer Deposition (ALD) process is reported for the first time using a previously unpublished set of precursors, namely bis(t-butylimido)bis(dimethylamino)molybdenum and hydrogen sulfide. These nanosheets are homogenously deposited within one-dimensional anodic TiO2 nanotube layers that act as a high surface area conductive support for the MoS2 nanosheets. The decoration of high aspect ratio TiO2 nanotube layers with MoS2 nanosheets over the entire nanotube layer thickness is shown for the first time. The homogeneous distribution of the MoS2 nanosheets is proved by STEM/EDX. This resulting new composite is employed as anode for Li-ion microbatteries. The MoS2-decorated TiO2 nanotube layers show a superior performance compared to their counterparts without MoS2. Compared to electrochemical performance of pristine TiO2 nanotube, a more than 50% higher areal capacity and a coulombic efficiency of 98% are obtained on the MoS2 decorated TiO2 nanotube layers, demonstrating clear synergic benefits of the new composite structure. (C) 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).