An overview of Forward Dynamics Algorithms and their use in Open Source Dynamics Engines

Simulation of real-world dynamics is of major importance in testing and verifying developed industrial concepts and solutions, developing and verifying potential control paradigms, scientific research, learning and training tools, or the entertainment industry as a basis for a game engine. The module of the 3D virtual simulator that achieves simulation of the real-world behaviour such as rigid and elastic body dynamics, particle dynamics, fluid dynamics, electrodynamics, magnetism, etc., is often referred to as a dynamics engine or physics engine. The core of the rigid body dynamics (physics) engine is the solution to the forward dynamics problem, which is defined as finding a rigid body's path, velocity, and acceleration for a given input actuating torque and external forces. The past few decades saw a considerable amount of research in robot dynamics modelling, and there are many methods for robot dynamic model development available in the literature. The most commonly used algorithms for solving robot forward dynamics problem are the Composite-Rigid-Body Algorithm (CRBA) [1] and the Articulated-Body Algorithm (ABA) [2]. CRBA and ABA are reduced coordinate methods where known constraints, such as joints, are embedded in the formulation of the equations of motion. Besides reduced coordinate methods, there are maximal coordinate methods using Lagrange multipliers [3-4] to enforce constraints using constraint reaction forces

Micorrización de plantulas en contendor de Pinus nigra con Suillus granulates bajo condiciones de campo

Seedling mycorrhization acts as an efficient tool for improving the quality of seedlings. In this study, the effectiveness of Suillus granulatus, originating from Pinus heldreichii forests (Montenegro), to produce containerized ectomycorrhizal seedlings of autochthonous Pinus nigra in open field conditions was investigated. Spore (106, 107, 108) and vegetative (1:16, 1:8, 1:4) inoculation on ectomycorrhizal formation and seedling growth were tested. Spore and vegetative inoculums of autochthonous Pisolithus arhizus were used in the same trial as additional control treatments. The utilization of vegetative and spore inoculums of autochthonous S. granulatus has proven to be an effective method of obtaining containerized ectomycorrhizal P. nigra seedlings under open field conditions after 11 months. S. granulatus spore inoculations resulted in well developed ectomycorrhiza, decreasing the growth of the P. nigra seedlings in the first growing season. Mycelial inoculations resulted in slightly developed S. granulatus ectomycorrhiza, which increased the growth of the seedlings. Therefore, it would be feasible to use spore inocula of S. granulatus, with 106 spores per plant, to produce ectomycorrhizal P. nigra plants on a large scale. Controlled mycorrhizal inoculation of seedlings is not a common practice in Montenegrin and Serbian nurseries; as such, the obtained results will contribute to the enhancement of nursery production of Pinus nigra and other conifers. This also could be assumed as a starting point for many further efforts and investigations with autochthonous fungal and plant material in this region.La micorrización de plántulas actúa como una herramienta eficaz para la mejora de la calidad de los brinzales. En este estudio se investiga la eficacia de Suillus granulatus, procedentes de bosques de Pinus heldreichii (Montenegro), para producir plántulas ectomicorrícicas en contenedores de Pinus nigra autóctonos en condiciones de campo. Se ensayaron inoculacion por esporas (106, 107, 108) y vegetativa (1:16, 1:8, 1:4) para la formación ectomicorrízica y el crecimiento de las plántulas. Se utilizó inóculo de esporas y vegetativo de Pisolithus arhizus autóctonos en el mismo ensayo como tratamiento control. La utilización de inóculos vegetativos y esporas de S. granulatus autóctonos ha demostrado ser un método eficaz para la obtención de plantas en contenedor ectomicorrícicas de P. nigra bajo condiciones de campo después de 11 meses. La inoculación de esporas de S. granulatus produjeron un buen desarrollo ectomicorrizas, disminuyendo el crecimiento de las plántulas de P. nigra en la primera estación de crecimiento. Las inoculaciones miceliales produjeron un escaso desarrollo ectomicorrizico de S. granulatus, con aumento en el crecimiento de las plántulas. Por lo tanto, sería factible el uso de inóculos de esporas de S. granulatus, con 106 esporas por planta, para producir plantas ectomicorrícicas de P. nigra a gran escala. La inoculación micorrízica controlada de plántulas no es una práctica común en los viveros de Serbia y Montenegro y, como tal, los resultados obtenidos contribuirán a la mejora de la producción en viveros de Pinus nigra y otras coníferas. Esto también podría ser asumido como un punto de partida para futuras investigaciones con material autóctono de hongos y plantas en esta región

Lattice dynamics of FeSb2

The lattice dynamics of FeSb2 is investigated by the first-principles DFT calculations and Raman spectroscopy. All Raman and infra-red active phonon modes are properly assigned. The calculated and measured phonon energies are in good agreement except for the B3g symmetry mode. We have observed strong mixing of the Ag symmetry modes, with the intensity exchange in the temperature range between 210 K and 260 K. The Ag modes repulsion increases by doping FeSb2 with Co. There are no signatures of the electron-phonon interaction for these modes

Impact and process assessment of the seven CITYLAB implementations

CITYLAB focuses on four axes that call for improvement and intervention: •Highly fragmented last-mile deliveries in city centres •Inefficient deliveries to large freight attractors and public administrations •Urban waste, return trips and recycling •Logistics sprawl Within these axes, the project supports seven implementations that are being tested, evaluated and rolled out. An implementation is defined as the process of preparing, testing and putting into practice a new service or a new way of operating or organising logistics activities. The objective of this report is to present an assessment of the effects and consequences of the implementations as they are conducted. For each case, we summarise the process leading to the application of a specific technical and managerial solution, and present the outcomes. For each implementation, we present •Problem and aim •Description of the solution •Implementation process •Effects and consequences •Challenges ahead •Lessons and generalisation of results This deliverable provides a complete picture of the evolvement of the implementations during the CITYLAB project and final versions of the process and impact assessment

A widespread family of bacterial cell wall assembly proteins

Teichoic acids and acidic capsular polysaccharides are major anionic cell wall polymers (APs) in many bacteria, with various critical cell functions, including maintenance of cell shape and structural integrity, charge and cation homeostasis, and multiple aspects of pathogenesis. We have identified the widespread LytR–Cps2A–Psr (LCP) protein family, of previously unknown function, as novel enzymes required for AP synthesis. Structural and biochemical analysis of several LCP proteins suggest that they carry out the final step of transferring APs from their lipid-linked precursor to cell wall peptidoglycan (PG). In Bacillus subtilis, LCP proteins are found in association with the MreB cytoskeleton, suggesting that MreB proteins coordinate the insertion of the major polymers, PG and AP, into the cell wall