Language-enhanced RNR-Map: Querying Renderable Neural Radiance Field maps with natural language

We present Le-RNR-Map, a Language-enhanced Renderable Neural Radiance map for Visual Navigation with natural language query prompts. The recently proposed RNR-Map employs a grid structure comprising latent codes positioned at each pixel. These latent codes, which are derived from image observation, enable: i) image rendering given a camera pose, since they are converted to Neural Radiance Field; ii) image navigation and localization with astonishing accuracy. On top of this, we enhance RNR-Map with CLIP-based embedding latent codes, allowing natural language search without additional label data. We evaluate the effectiveness of this map in single and multi-object searches. We also investigate its compatibility with a Large Language Model as an "affordance query resolver". Code and videos are available at https://intelligolabs.github.io/Le-RNR-Map/Comment: Accepted at ICCVW23 VLA

Reversible hydrogen sorption in the composite made of magnesium borohydride and silica aerogel

Magnesium borohydride Mg(BH4)2 is a promising hydrogen storage material as it releases high hydrogen storage capacity at mild desorption temperatures, but it is still limited by slow hydrogen release kinetics and by the harsh conditions required to re-hydrogenate this compound. In this work, composites made of commercial Mg(BH4)2 and synthesized silica aerogel microparticles were prepared by thermal treatment in hydrogen under 120 bar and 200ºC. As a result, the sorption properties of the hydride are improved: calorimetric measurements show that decomposition temperature is reduced by 60ºC, and the typical 3-step decomposition mechanism of Mg(BH4)2 changes to a single-step mechanism in range of 220-400°C. The kinetics of the first dehydrogenation at 300ºC was two times faster in Mg(BH4)2-SiO2 composites than in the case of bulk γ-Mg(BH4)2. Additionally, the re-hydrogenation of this material at comparatively moderate conditions of 390ºC and 110 bar is presented for the first time, achieving cyclability with a reversible release of hydrogen up to 6wt%. Different amounts of hydrogen were exchanged depending on the temperature of desorption (300ºC or 400ºC) and the presence or absence of silica aerogel. This result indicates that silica aerogel chemically interacts with Mg(BH4)2, acting as an additive, which can result in different hydrogenation-dehydrogenation routes in which different amounts and types of intermediates are formed, influencing the kinetics and the cyclability.2018-07-27Spanish Ministry of Economy and Competitiveness project ENE2014-53459-

Optimal hydrogen storage in sodium substituted lithium fullerides

A relevant improvement in the hydrogen storage capability of lithium fullerides is obtained by the co-intercalation of a small amount of sodium

Fundamental material properties of the 2LiBH4-MgH2 reactive hydride composite for hydrogen storage: (II) Kinetic properties

Reaction kinetic behaviour and cycling stability of the 2LiBH4-MgH2 reactive hydride composite (Li-RHC) are experimentally determined and analysed as a basis for the design and development of hydrogen storage tanks. In addition to the determination and discussion about the properties; different measurement methods are applied and compared. The activation energies for both hydrogenation and dehydrogenation are determined by the Kissinger method and via the fitting of solid-state reaction kinetic models to isothermal volumetric measurements. Furthermore, the hydrogen absorption-desorption cycling stability is assessed by titration measurements. Finally, the kinetic behaviour and the reversible hydrogen storage capacity of the Li-RHC are discussed.Fil: Jepsen, Julian. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; AlemaniaFil: Milanese, Chiara. Università degli Studi di Pavia; ItaliaFil: Puszkiel, Julián Atilio. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Girella, Alessandro. Università degli Studi di Pavia; ItaliaFil: Schiavo, Benedetto. Università degli Studi di Palermo; ItaliaFil: Lozano, Gustavo A.. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; AlemaniaFil: Capurso, Giovanni. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; AlemaniaFil: Von Colbe, José M. Bellosta. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; AlemaniaFil: Marini, Amedeo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Kabelac, Stephan. Leibniz Universität Hannover; AlemaniaFil: Dornheim, Martin. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; AlemaniaFil: Klassen, Thomas. Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung; Alemani

Mechanothermal Solid-state Synthesis of Cobalt(II) Ferrite and Determination of its Heat Capacity by MTDSC

Cobalt ferrite (CoFe2O4) has been synthesized by a solid-state mechanothermal process, and its molar heat capacity has been determined. A stoichiometric mixture of CoC2O4 ・ 2H2O and FeC2O4 ・ 2H2O was subjected to a combination of mechanical activation (by high-energy milling) and thermal activation (by annealing at temperatures between 300 and 700 °C). The process was followed by thermogravimetric analysis and high-temperature X-ray powder diffraction. It has been shown that CoFe2O4 forms at all temperatures, though with different degrees of crystallization, while Co3O4 and Fe2O3 are the only products formed when starting from unmilled mixtures. The molar heat capacity of CoFe2O4 has been determined in the temperature range 60 - 400 °C by MTDSC. It has been shown that the molar CP values of CoFe2O4 samples produced at T ≥ 500 °C are close to each other while those of the samples produced at 300 and 400 °C are lower. Furthermore the CoFe2O4 samples prepared at T ≥ 500 °C show very similar microstructures

Fundamental material properties of the 2LiBH4-MgH2 reactive hydride composite for hydrogen storage: (I) Thermodynamic and heat transfer properties

Thermodynamic and heat transfer properties of the 2LiBH4-MgH2 composite (Li-RHC) system are experimentally determined and studied as a basis for the design and development of hydrogen storage tanks. Besides the determination and discussion of the properties, different measurement methods are applied and compared to each other. Regarding thermodynamics, reaction enthalpy and entropy are determined by pressure-concentration-isotherms and coupled manometric-calorimetric measurements. For thermal diffusivity calculation, the specific heat capacity is measured by high-pressure differential scanning calorimetry and the effective thermal conductivity is determined by the transient plane source technique and in situ thermocell. Based on the results obtained from the thermodynamics and the assessment of the heat transfer properties, the reaction mechanism of the Li-RHC and the issues related to the scale-up for larger hydrogen storage systems are discussed in detail.Fil: Jepsen, Julian. Helmholtz-Zentrum Geesthacht; AlemaniaFil: Milanese, Chiara. University of Pavia; ItaliaFil: Puszkiel, Julián Atilio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Helmholtz-Zentrum Geesthacht; AlemaniaFil: Girella, Alessandro. University of Pavia; ItaliaFil: Schiavo, Benedetto. Universidad de Palermo; Argentina. Istituto per le Tecnologie Avanzate; ItaliaFil: Lozano, Gustavo A.. Helmholtz-Zentrum Geesthacht; Alemania. BASF; AlemaniaFil: Capurso, Giovanni. Helmholtz-Zentrum Geesthacht; AlemaniaFil: Von Colbe, José M. Bellosta. Helmholtz-Zentrum Geesthacht; AlemaniaFil: Marini, Amedeo. University of Pavia; ItaliaFil: Kabelac, Stephan. Leibniz Universität Hannover; AlemaniaFil: Dornheim, Martin. Helmholtz-Zentrum Geesthacht; AlemaniaFil: Klassen, Thomas. Helmholtz-Zentrum Geesthacht; Alemani

Effect of the process parameters on the energy transfer during the synthesis of the 2LiBH4/MgH2 reactive hydride composite for hydrogen storage

: Several different milling parameters (additive content, rotation velocity, ball-to-powder ratio, degree of filling, and time) affect the hydrogen absorption and desorption properties of a reactive hydride composite (RHC). In this paper, these effects were thoroughly tested and analyzed. The milling process investigated in such detail was performed on the 2LiH-MgB2 system doped with TiCl3. Applying an upgraded empirical model, the transfer of energy to the material during the milling process was determined. In this way, it is possible to compare the obtained experimental results with those from processes at different scales. In addition, the different milling parameters were evaluated independently according to their individual effect on the transferred energy. Their influence on the reaction kinetics and hydrogen capacity was discussed and the results were correlated to characteristics like particle and crystallite size, specific surface area, presence of nucleation sites and contaminants. Finally, an optimal value for the transferred energy was determined, above which the powder characteristics do not change and therefore the RHC system properties do not further improve.Fil: Jepsen, Julian. Helmholtz zentrum Geesthacht; Alemania. Helmut Schmidt University; AlemaniaFil: Capurso, Giovanni. Helmholtz zentrum Geesthacht; AlemaniaFil: Puszkiel, Julián Atilio. Helmholtz zentrum Geesthacht; Alemania. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Busch, Nina. Helmholtz zentrum Geesthacht; AlemaniaFil: Werner, Tobias. Helmholtz zentrum Geesthacht; AlemaniaFil: Milanese, Chiara. Universita Degli Studi Di Pavia; ItaliaFil: Girella, Alessandro. Universita Degli Studi Di Pavia; ItaliaFil: Von Colbe, José Bellosta. Helmholtz zentrum Geesthacht; AlemaniaFil: Dornheim, Martin. Helmholtz zentrum Geesthacht; AlemaniaFil: Klassen, Thomas. Helmholtz zentrum Geesthacht; Alemania. Helmut Schmidt University; Alemani

Synthesis of LaCoO3 powder by a combined mechanical/thermal process

Lanthanum cobaltite, LaCoO3, finds applications as an oxidation and reduction catalyst in gas-sensing materials and in electrode materials for high-temperature fuel cells. The compound has been synthesized through several routes aimed at obtaining LaCoO3 at lower temperatures. We propose a synthetic procedure based on the combined use of mechanical and thermal energy on mixtures of Co(II) oxalate dehydrate and La acetate sesquihydrate. We studied the reactions taking place by increasing the temperature. The study has been performed either on mixtures prepared by a simple physical mixing of the reactants or on the same mixtures after having been subjected to mechanical activation by high-energy milling. The products formed in the mixtures by annealing at different temperatures have been characterized by means of different experimental techniques

Synthesis of calcium metastannate (CaSnO<inf>3</inf>) by solid state reactions in mechanically activated mixtures calcium citrate tetra hydrate [Ca<inf>3</inf>(C<inf>6</inf>H<inf>5</inf>O<inf>7</inf>)<inf>2</inf>·4H<inf>2</inf>O] - Tin(II) oxalate (SnC<inf>2</inf>O<inf>4</inf>)

Many synthesis procedures have been worked out to prepare CaSnO3. A great deal of them resort to the classical ceramic method that implies a very high temperature treatment (1300-1500 degrees C) of the component oxides mixture. To avoid such high temperature treatment, many alternative routes have been proposed. In this paper stoichiometric mixtures of Ca citrate tetrahydrate and Sn(II) oxalate have been mechanically activated by high energy milling. The reactions taking place in the mixtures during annealing have been studied by coupled TG-DSC measurements, XRPD and diffuse reflectance FT-IR spectroscopy. It has been established that the stage of mechanical activation allows the synthesis to be completed by 3 h-annealing at 850 degrees C. (C) 2015 Elsevier B.V. All rights reserved