LoRa Enabled Smart Inverters for Microgrid Scenarios with Widespread Elements

The introduction of low-power wide-area networks (LPWANs) has changed the image of smart systems, due to their wide coverage and low-power characteristics. This category of communication technologies is the perfect candidate to be integrated into smart inverter control architectures for remote microgrid (MG) applications. LoRaWAN is one of the leading LPWAN technologies, with some appealing features such as ease of implementation and the possibility of creating private networks. This study is devoted to analyze and evaluate the aforementioned integration. Initially, the characteristics of different LPWAN technologies are introduced, followed by an in-depth analysis of LoRa and LoRaWAN. Next, the role of communication in MGs with widespread elements is explained. A point-by-point LoRa architecture is proposed to be implemented in the grid-feeding control structure of smart inverters. This architecture is experimentally evaluated in terms of latency analysis and externally generated power setpoint, following smart inverters in different LoRa settings. The results demonstrate the effectiveness of the proposed LoRa architecture, while the settings are optimally configured. Finally, a hybrid communication system is proposed that can be effectively implemented for remote residential MG management

Holocene fossil woods from the Caldera de Taburiente National Park (Canary Islands, Spain)

The study of 39 Pinus canariensis Holocene fossil woods from the Caldera de Taburiente is presente

Kontrola snopa aktivnih reflektorskih nizova

Active reflectarrays having beam control are presented in this paper. The steering capability is obtained by achieving different amplitude and phase of the scattered field from each reflectarray element, which is controlled by the use of an IQ modulator in some cases. An aperture coupled patch with perpendicular microstrip feeds is employed as radiating element. One of its ports is employed to receive the signal and the other to retransmit it with the phase and gain selected in the amplitude/phase control unit. The beam control can be also obtained by means of switching circuit. A laboratory experience with 1-bit reflectarray of 4 × 4 elements shows the beam control performance, and a study to simplify manufacturing process of 3-bit reflectarray is also presented.U ovom su radu prikazani aktivni reflektorski nizovi s kontrolom snopa. Sposobnost zakretanja snopa dobivena je primjenom različitih amplituda i faza raspršenog polja iz elementa reflektorskog niza, koji je kontroliran uporabom IQ modulatora. Kao zračeći element upotrijebljen je patch spregnut preko otvora s okomitim mikrotrakastim pobudnim linijama. Jedan od njegovih prolaza je iskorišten za prijam signala, a drugi za reemitiranje istog signala s fazom i pojačanjem odabranim u kontrolnoj jedinici amplitude i faze. Kontrola snopa može se također dobiti pomoću prekidačkog sklopa. Laboratorijska iskustva s 1-bitnim reflektorskim nizom s 4 × 4 elementa pokazuje preformance kontrole snopa, a također je prikazano i istraživanje na pojednostavljenju proizvodnog procesa 3-bitnog reflektorskog niza

Quorum Sensing is essential for an effective symbiosis in R. leguminosarum UPM791.

The implications of Quorum Sensing in the establishment of a successful symbiosis of Rhizobium leguminosarum bv. viciae (Rlv) with legume plants are discussed in this work. In order to analyze the significance and regulation of the production of AHL signal molecules, mutants deficient in each of the two QS systems present in Rlv UPM791 were constructed. A detailed analysis of the effect of these mutations on growth, AHL production, biofilm formation and symbiosis with pea, vetch and lentil plants has been carried out

Efecto de los sistemas de Quorum Sensing sobre la eficiencia simbiótica de R. leguminosarum UPM791

Rhizobium leguminosarum bv viciae (Rlv) es una alfa-proteobacteria capaz de establecer una simbiosis diazotrófica con distintas leguminosas. Uno de los factores implicados en el establecimiento de la simbiosis es el sistema de comunicación intercelular conocido como Quorum Sensing (QS). Mediante este sistema, las bacterias actúan de manera coordinada en respuesta a cambios en la densidad de población a través de la producción y detección de señales extracelulares. El genoma de Rlv UPM791 contiene dos sistemas tipo luxRI mediados por señales de tipo N-acyl-homoserina lactonas (AHLs): el sistema rhiRI, codificado en el plásmido simbiótico, produce C6-HSL, C7-HSL y C8-HSL; y el sistema cinRI, localizado en el cromosoma, produce 3-OH-C14:1-HSL. Con el fin de analizar el significado y la regulación de los sistemas de QS en esta bacteria endosimbiótica se generaron mutantes defectivos en cada uno de los sistemas de QS, y se llevó a cabo un análisis detallado sobre la producción de AHLs y la simbiosis con plantas de guisante, veza y lenteja. El sistema rhiRI se necesita para un comportamiento simbiótico normal, dado que la mutación en rhiI reduce considerablemente la eficiencia simbiótica. rhiR es esencial para la fijación de nitrógeno en ausencia del plásmido pUPM791d. Asimismo, mutaciones en el sistema cinRIS mostraron también un importante efecto en simbiosis. El mutante ?cinRIS no produce la señal 3-OH-C14:1-HSL, y da lugar a nódulos blancos e inefectivos, carentes de bacteroides. El mutante ?cinI, incapaz de producir AHLs, no forma nódulos en ninguna de las leguminosas utilizadas. El análisis genético reveló que dicha mutación origina la inestabilización del plásmido simbiótico por un mecanismo dependiente de cinI que no ha sido aclarado. Los resultados obtenidos sugieren un papel relevante de los sistemas de Quorum Sensing de Rlv UPM791 en los primeros estadíos de la simbiosis, e indican la existencia de un modelo de regulación dependiente de QS significativamente distinto a los que se han descrito previamente en otras cepas de R. leguminosarum

Accacoelium contortum (Trematoda : Accacoeliidae) a trematode living as a monogenean: morphological and pathological implications

Accacoelium contortum (Rudolphi, 1819) Monticelli, 1893 is a frequent but poorly known trematode found on gills, pharynx and digestive tract of the ocean sunfish Mola mola (L.). Although the morphology of A. contortum agrees with that of a typical endoparasitic trematode, with two relatively small suckers and no large holdfasts, this parasite is normally ectoparasitic. The main objective of this paper is to explore this peculiar host-parasite relationship. A total of 106 ocean sunfish were examined for the presence of A. contortum. The oropharyngeal chamber (gills and pharynx) and the digestive tract were analysed. As the previous descriptions of this species seem to be based on contracted specimens, for the morphological study the parasites were killed using two methods: with hot 70 % ethanol (with relaxed bodies) and with 70 % ethanol at room temperature (with contracted bodies). For histological studies, samples from fresh fish with parasitised left gills, pharynx and digestive tract were fixed in buffered 10 % formalin. For molecular studies the 18S, 28S and ITS-2 sequences were provided and compared with the available data in GenBank®. New information on the morphology of A. contortum and on the parasite-related response and pathological alterations in the host are given. New diagnostic traits for some structures are provided: e.g. tegumental papillae of the forebody with apical digitiform swellings and mouth surrounded by a circum-oral crown of simple papillae. The length of the ventral sucker peduncle and the position of the vitellarium were found to be associated with the contraction degree of the specimen. Immature individuals of this species are described for the first time. An intense proliferative inflammatory response of host gill and pharynx epithelium at the host-parasite interface was detected and parasites became partially covered by overgrowths of host tissues. The induction of prominent histological alterations associated with A. contortum seems to be an adaptation to the external environment, an unusual location for trematodes