Orbital angular momentum induced beam shifts

We present experiments on Orbital Angular Momentum (OAM) induced beam shifts in optical reflection. Specifically, we observe the spatial Goos-H\"anchen shift in which the beam is displaced parallel to the plane of incidence and the angular Imbert-Fedorov shift which is a transverse angular deviation from the geometric optics prediction. Experimental results agree well with our theoretical predictions. Both beam shifts increase with the OAM of the beam; we have measured these for OAM indices up to 3. Moreover, the OAM couples these two shifts. Our results are significant for optical metrology since optical beams with OAM have been extensively used in both fundamental and applied research.Comment: 7 pages, 7 figure

How orbital angular momentum affects beam shifts in optical reflection

It is well known that reflection of a Gaussian light beam ($\text{TEM}_{00}$) by a planar dielectric interface leads to four beam shifts when compared to the geometrical-optics prediction. These are the spatial Goos-H\"{a}nchen (GH) shift, the angular GH shift, the spatial Imbert-Fedorov (IF) shift and the angular IF shift. We report here, theoretically and experimentally, that endowing the beam with Orbital Angular Momentum (OAM) leads to coupling of these four shifts; this is described by a $4 \times 4$ mixing matrix.Comment: v2 Version accepted for publication in Phys. Rev.

Real-time extensive livestock monitoring using lpwan smart wearable and infrastructure

Extensive unsupervised livestock farming is a habitual technique in many places around the globe. Animal release can be done for months, in large areas and with different species packing and behaving very differently. Nevertheless, the farmer’s needs are similar: where livestock is (and where has been) and how healthy they are. The geographical areas involved usually have difficult access with harsh orography and lack of communications infrastructure. This paper presents the design of a solution for extensive livestock monitoring in these areas. Our proposal is based in a wearable equipped with inertial sensors, global positioning system and wireless communications; and a Low-Power Wide Area Network infrastructure that can run with and without internet connection. Using adaptive analysis and data compression, we provide real-time monitoring and logging of cattle’s position and activities. Hardware and firmware design achieve very low energy consumption allowing months of battery life. We have thoroughly tested the devices in different laboratory setups and evaluated the system performance in real scenarios in the mountains and in the forest

Malecón de la Habana: cronología de una historia urbana

This article explores through the logical-historical and chronological method in the process of construction of Malecón Avenue in Havana in Cuba. This in relation to the geographical, historical, sociopolitical circumstances of the country and from its articulation with the main architectural works of the city. In this sense, the work in question stands out as an urban axis of the capital and carried out for fifty years to the light of various presidents to power. The main contribution of the study is the integration and organization of the documentary and informative collection in this respect and that is dispersed in different sources of national reference. It also encourages the circulation of content related to Latin American historical processes and that allow to consolidate the historiographical memory of the past, in particular of the Caribbean. Finally, it is possible to reflect and debate about the discursive configuration of architectural, urban works constructed and the habitants of the capital that contributed to the conformation of the social reality of the city.El presente artículo indaga a través del método histórico-lógico y cronológico en el proceso de construcción de la Avenida Malecón de La Habana en Cuba. Ello, en relación con las circunstancias geográficas, históricas, sociopolíticas del país y a partir de su articulación con las principales obras arquitectónicas de la ciudad. En este sentido, destaca la obra en cuestión como eje urbanístico de la capital y llevada a cabo durante cincuenta años a la luz de los diversos presidentes. El aporte principal del estudio es la integración y organización del acervo documental e informativo al respecto y que se encuentra disperso en diferentes fuentes de referencia nacional. Asimismo, se propicia la circulación de contenido referente a los procesos históricos latinoamericanos, que permiten consolidar la memoria historiográfica del pasado, en particular del Caribe. Finalmente, se posibilita reflexionar y debatir sobre la configuración discursiva tras las obras arquitectónicas y urbanas construidas, y sobre los habitantes de la urbe capitalina, que contribuyeron a la conformación de la realidad social de la ciudad

Genetic analyses place most Spanish isolates of Beauveria bassiana in a molecular group with word-wide distribution

<p>Abstract</p> <p>Background</p> <p>The entomopathogenic anamorphic fungus <it>Beauveria bassiana </it>is currently used as a biocontrol agent (BCA) of insects. Fifty-seven <it>Beauveria bassiana </it>isolates -53 from Spain- were characterized, integrating group I intron insertion patterns at the 3'-end of the nuclear large subunit ribosomal gene (LSU rDNA) and elongation factor 1-alpha (EF1-α) phylogenetic information, in order to assess the genetic structure and diversity of this Spanish collection of <it>B. bassiana</it>.</p> <p>Results</p> <p>Group I intron genotype analysis was based on the four highly conserved insertion sites of the LSU (Ec2653, Ec2449, Ec2066, Ec1921). Of the 16 possible combinations/genotypes, only four were detected, two of which were predominant, containing 44 and 9 members out of 57 isolates, respectively. Interestingly, the members of the latter two genotypes showed unique differences in their growth temperatures. In follow, EF1-α phylogeny served to classify most of the strains in the <it>B. bassiana s.s</it>. (<it>sensu stricto</it>) group and separate them into 5 molecular subgroups, all of which contained a group I intron belonging to the IC1 subtype at the Ec1921 position. A number of parameters such as thermal growth or origin (host, geographic location and climatic conditions) were also examined but in general no association could be found.</p> <p>Conclusion</p> <p>Most Spanish <it>B. bassiana </it>isolates (77.2%) are grouped into a major phylogenetic subgroup with word-wide distribution. However, high phylogenetic diversity was also detected among Spanish isolates from close geographic zones with low climatic variation. In general, no correlation was observed between the molecular distribution and geographic origin or climatic characteristics where the Spanish <it>B. bassiana </it>isolates were sampled.</p

Thermosetting Polyurethane Resins as Low-Cost, Easily Scalable, and Effective Oxygen and Moisture Barriers for Perovskite Solar Cells

Long-term stability of perovskite solar cells (PSCs) is one of the main issues to be solved for forthcoming commercialization of this technology. In this work, thermosetting polyurethane (PU)-based resins are proposed as effective encapsulants for perovskite solar cells to prevent degradation caused by both moisture and oxygen. Application consists of drop-casting the precursor mixture directly over the devices followed by in situ polymerization, avoiding the use of other adhesives. PUs are cost-effective, lightweight, thermal, and light-stable materials whose mechanical, chemical, and physical properties can be easily tuned by thoughtful choice of their precursor. Encapsulated PSCs show extremely good stability when stored under ambient light (maximum, 1000 lux), controlled humidity (28-65%), and temperature (18-30 degrees C) by retaining 94% of the initial power conversion efficiency after 2500 h (4 months), whereas control devices lose 90% of their performance after 500 h (T-80 = 37 h); once stored according to ISOS-D-1, PU-protected devices showed T-80 &gt; 1200 h. Encapsulated devices are stable even when immersed in pure water. The demonstration of PUs as promising solution-processed encapsulant materials for PSCs can pave the way for these to become a cost-effective encapsulation route alternative for future industrialization of this technology

Unexplored outflows in nearby low luminosity AGNs: the case of NGC 1052

Outflows play a central role in galaxy evolution shaping the properties of galaxies. Understanding outflows and their effects in low luminosity AGNs, such as LINERs, is essential (e.g. they are a numerous AGN population in the local Universe). We obtained VLT/MUSE and GTC/MEGARA optical IFS-data for NGC1052, the prototypical LINER. The stars are distributed in a dynamically hot disc, with a centrally peaked velocity dispersion map and large observed velocity amplitudes. The ionised gas, probed by the primary component is detected up to $\sim$30arcsec ($\sim$3.3 kpc) mostly in the polar direction with blue and red velocities ($\mid$V$\mid$$<$250 km/s). The velocity dispersion map shows a notable enhancement ($\sigma$$>$90 km/s) crossing the galaxy along the major axis of rotation in the central 10arcsec. The secondary component has a bipolar morphology, velocity dispersion larger than 150 km/s and velocities up to 660 km/s. A third component is detected but not spatially resolved. The maps of the NaD absorption indicate optically thick neutral gas with a velocity field consistent with a slow rotating disc ($\Delta$V = 77$\pm$12 km/s) but the velocity dispersion map is off-centred without any counterpart in the flux map. We found evidence of an ionised gas outflow with mass of 1.6$\pm$0.6 $\times$ 10$^{5}$ Msun, and mass rate of 0.4$\pm$0.2 Msun/yr. The outflow is propagating in a cocoon of gas with enhanced turbulence and might be triggering the onset of kpc-scale buoyant bubbles (polar emission). Taking into account the energy and kinetic power of the outflow (1.3$\pm$0.9 $\times$ 10$^{53}$ erg and 8.8$\pm$3.5 $\times$ 10$^{40}$ erg/s, respectively) as well as its alignment with both the jet and the cocoon, and that the gas is collisionally ionised, we consider that the outflow is jet-powered, although some contribution from the AGN is possible.Comment: A&A accepted 04/04/2022, 31 pages, 12 figures and 3 appendixe

Electrophoretic mobility of supercoiled, catenated and knotted DNA molecules.

We systematically varied conditions of two-dimensional (2D) agarose gel electrophoresis to optimize separation of DNA topoisomers that differ either by the extent of knotting, the extent of catenation or the extent of supercoiling. To this aim we compared electrophoretic behavior of three different families of DNA topoisomers: (i) supercoiled DNA molecules, where supercoiling covered the range extending from covalently closed relaxed up to naturally supercoiled DNA molecules; (ii) postreplicative catenanes with catenation number increasing from 1 to ∼15, where both catenated rings were nicked; (iii) knotted but nicked DNA molecules with a naturally arising spectrum of knots. For better comparison, we studied topoisomer families where each member had the same total molecular mass. For knotted and supercoiled molecules, we analyzed dimeric plasmids whereas catenanes were composed of monomeric forms of the same plasmid. We observed that catenated, knotted and supercoiled families of topoisomers showed different reactions to changes of agarose concentration and voltage during electrophoresis. These differences permitted us to optimize conditions for their separation and shed light on physical characteristics of these different types of DNA topoisomers during electrophoresis