High-performance 16-way Ku-band radial power combiner based on the TE01-circular waveguide mode

This work presents a 16-way Ku-band radial power combiner for high power and high frequency applications, using the very low loss TE01 circular waveguide mode. The accomplished design shows an excellent performance: the experimental prototype has a return loss better than 30 dB, with a balance for the amplitudes of ( 0.15 dB) and ( 2.5 ) for the phases, in a 16.7% fractional bandwidth (2 GHz centered at 12 GHz). For obtaining these outstanding specifications, required, for instance, in highfrequency amplification or on plasma systems, a rigorous step-by-step procedure is presented. First, a high-purity mode transducer has been designed, from the TE10 mode in the rectangular waveguide to the TE01 mode in the circularwaveguide, with very high attenuation (>50 dB) for the other propagating and evanescent modes in the circularwaveguide. This transducer has been manufactured and measured in a back-to-back configuration, validating the design process. Second, an E-plane 16-way radial power divider has been designed, where the power is coupled from the 16 non-reduced-height radial standardwaveguides into the TE01 circularwaveguide mode, improving the insertion loss response and removing the usual tapered transformers of previous designs limiting the power handling. Finally, both the transducer and the divider have been assembled to make the final radial combiner. The prototype has been carefully manufactured, showing very good agreement between the measurements and the full-wave simulationsThe authors would like to thank INMEPRE S.A., the diligence in the manufacturing process. This work was supported by the Spanish government under Grant (ADDMATE) No. TEC2016-76070-C3-1/2-R (AEI/FEDER/UE) and the program of Comunidad de Madrid S2013/ICE-3000 (SPADERADARCM

Flume study on the effects of microbial induced calcium carbonate precipitation (MICP) on the erosional behaviour of fine sand

Tangential flow-induced interface erosion poses a major threat to a wide variety of engineering structures, such as earth-filled embankment dams, and oil- and gas-producing wells. This study explores the applicability of microbial induced calcium carbonate (CaCO3) precipitation (MICP) by way of the ureolytic soil bacterium Sporosarcina pasteurii as a method for enhancing the surface erosion resistance of fine sand. Specimens were treated with cementation solution concentrations between 0·02 and 0·1 M, and the erosional behaviour examined in a flume under surface-parallel flow and increasing shear stress. Photographs, cumulative height eroded-time series and erosion rates were obtained as a function of specimen height, MICP treatment formulation and calcium carbonate content. Results showed that while untreated specimens eroded primarily in particulate and mass form, MICP-treated specimens were characterised by a block erosion mechanism. Further, erodibility was found to depend on the calcium carbonate content and the cementation solution concentration. To understand this, a systematic study of the calcium carbonate crystal sizes and distributions was undertaken through X-ray computed tomography. Fundamentally, the effectiveness of MICP for erosion control was found to be dominated both by the precipitated calcium carbonate content and microstructural features, with higher contents and larger crystals yielding lower erodibility values. Additionally, crystal growth mechanisms varied depending on the cementation solution concentration.</p

Who victimizes whom and who defends whom? A multivariate social network analysis of victimization, aggression, and defending in early childhood

The aim of this research was to investigate the interplay between victim-aggressor relationships and defending relationships in early childhood to test the proposition that young aggressors are less selective than older children in their choice of vulnerable targets. Cross-sectional multivariate statistical social network analyses (Exponential Random Graph Models) for a sample of 177 preschoolers from seven classes, 5- to 7-years-old, revealed that boys were more aggressive than girls, towards both boys and girls, whereas defending relationships were most often same-sex. There was significant reciprocity in aggression, indicating that it was more often bidirectional rather than unidirectional. In addition, aggressors clearly defended each other when they shared their targets of aggression, whereas a marginally significant trend appeared for defending between victims who were victimized by the same aggressors. Furthermore, teacher-rated dominance was positively associated with children’s involvement in both aggression and victimization, and teacher-rated insecurity was associated with less aggression, but not with victimization. These findings suggest that those who are reported as being victimized may retaliate, or be aggressive themselves, and do not display some of the vulnerabilities reported among older groups of victims. The findings are in line with the proposition that young aggressors are less strategic than older children in targeting vulnerable victims. The network approach to peer victimization and defending contributes to understanding the social processes facilitating the development of aggression in early childhood

A Metabolically Healthy Profile Is a Transient Stage When Exercise and Diet Are Not Supervised: Long-Term Effects in the EXERDIET-HTA Study

Metabolically unhealthy obesity (MUO) is a regular state in people with primary hypertension (HTN), obesity, and who are physically inactive. To achieve and maintain a metabolically healthy overweight/obese (MHO) state should be a main treatment goal. The aims of the study were (1) to determine differences in metabolic profiles of overweight/obese, physically inactive individuals with HTN following a 16-week (POST) supervised aerobic exercise training (SupExT) intervention with an attentional control (AC) group, and (2) to determine whether the changes observed were maintained following six months (6 M) of unsupervised time. Participants (n = 219) were randomly assigned into AC or SupExT groups. All participants underwent a hypocaloric diet. At POST, all participants received diet and physical activity advice for the following 6 M, with no supervision. All measurements were assessed pre-intervention (PRE), POST, and after 6 M. From PRE to POST, MUO participants became MHO with improved (p < 0.05) total cholesterol (TC, ∆ = −12.1 mg/dL), alanine aminotransferase (∆ = −8.3 U/L), glucose (∆ = −5.5 mg/dL), C-reactive protein (∆ = −1.4 mg/dL), systolic blood pressure (SBP), and cardiorespiratory fitness (CRF) compared to unhealthy optimal cut-off values. However, after 6 M, TC, glucose, and SBP returned to unhealthy values (p < 0.05). In a non-physically active population with obesity and HTN, a 16-week SupExT and diet intervention significantly improves cardiometabolic profile from MUO to MHO. However, after 6 M of no supervision, participants returned to MUO. The findings of this study highlight the need for regular, systematic, and supervised diet and exercise programs to avoid subsequent declines in cardiometabolic health.P.C., A.M.A.-B., and I.G.-A. were supported by the Basque Government with predoctoral grants. This study was supported by the University of the Basque Country (EHU14/08, PPGA18/15)

Fabrication and deposition of copper and copper oxide nanoparticles by laser ablation in open air

The proximity of the “post-antibiotic era”, where infections and minor injuries could be a cause of death, there are urges to seek an alternative for the cure of infectious diseases. Copper nanoparticles and their huge potential as a bactericidal agent could be a solution. In this work, Cu and Cu oxide nanoparticles were synthesized by laser ablation in open air and in argon atmosphere using 532 and 1064 nm radiation generated by nanosecond and picosecond Nd:YVO4 lasers, respectively, to be directly deposited onto Ti substrates. Size, morphology, composition and the crystalline structure of the produced nanoparticles have been studied by the means of field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), the energy dispersive spectroscopy of X-rays (EDS), selected area electron diffraction (SAED) and X-ray diffraction (XRD). The UV-VIS absorbance of the thin layer of nanoparticles was also measured, and the antibacterial capacity of the obtained deposits tested against Staphylococcus aureus. The obtained deposits consisted of porous coatings composed of copper and copper oxide nanoparticles interconnected to form chain-like aggregates. The use of the argon atmosphere contributed to reduce significantly the formation of Cu oxide species. The synthesized and deposited nanoparticles exhibited an inhibitory effect upon S. aureus.Peer ReviewedPostprint (published version

Vulnerabilidad del acuífero en áreas del valle de Catamarca destinadas al reúso agrícola de agua residual tratada

La utilización  de aguas residuales tratadas para riego  plantea beneficios de carácter ambiental,  social y productivo. La Capital de Catamarca cuenta con un sistema de lagunas para depurar los efluentes cloacales. Atendiendo a la demanda de agua para actividades productivas y a la calidad del líquido depurado se implementará un proyecto de reuso. Simultáneamente se debe proteger la calidad del recurso hídrico subterráneo frente a esta carga. El objetivo de este trabajo es determinar la vulnerabilidad del acuífero a la contaminación en el área donde estará ubicado el emprendimiento productivo, sur de la planta de tratamiento. Se aplicó el método cualitativo GOD. Se determinó la profundidad del acuífero freático, tipo de acuífero y fitología del acuiperm, representada por arenas finas a muy gruesas, gravas y rodados con muy escasa proporción de limo y arcilla. La vulnerabilidad resultó moderada a alta, según el valor del índice. Se recomienda realizar un monitoreo sistemático del acuífero estudiado.The use of treated wastewater for irrigation has benefits of environmental, social and productive. The Catamarca capital has a ponds system for the wastewater treatment. In response to the water demand for productive activities and because of the quality the treated liquid will be implemented a reuse project. Simultaneously, must be protected the quality of groundwater resources against this load. The objective of this work is to determine aquifer contamination vulnerability in the area where productive entrepreneurship will be located, at the south of the treatment plant. It was applied qualitative method GOD. It were determined the depth of the aquifer, groundwater occurrence and lithology acuiperm, represented by fine to very coarse sand, gravel and boulders with very low proportion of silt and clay. The vulnerability was moderate to high, depending on the value of the index. It is recommend a systematic monitoring of the aquifer studied.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Eficiencia de las lagunas de estabilización de la ciudad de Catamarca y su relación con la estimada por los modelos de diseño

Los efluentes cloacales de la Capital de Catamarca son depurados utilizando lagunas de estabilización. La eficiencia de estos sistemas para la remoción de la carga orgánica y bacteriana es función de transformaciones bioquímicas y del régimen de flujo hidráulico. Existe una gran variedad de modelos de diseño para predecir las características del efluente. El objetivo del trabajo es determinar la eficiencia de remoción orgánica y bacteriana del sistema de lagunas de estabilización de la Capital, en relación con la estimada por los modelos de diseño. Se extrajeron muestras compensadas del líquido afluente y efluente. Se determinaron DBO5, CF utilizando técnicas del Standard Methods. Los mayores porcentajes de remoción DBO5 se encontraron en los módulos 3 y 6 (65 - 69 %), debajo de los valores estimados por los modelos (>82 %). Es baja la eficiencia de remoción de DBO5 pero existe buen ajuste del modelo para la remoción de CF.Wastewater of Catamarca capital, are cleaned using waste stabilization ponds. The effectiveness of these systems, for organic load and bacteria removal, depends on biochemistry changes and hydraulic flux. There are wide ranges of model design for predicting waste characteristics. Effectiveness for organic load and bacteria removal of stabilization ponds system of Catamarca Capital, regarding to designs, is the research purposes. Flows and outflows fluids of compensated samples were taken. BOD and CF were determined using Standard Methods techniques. Most percentages of BOD removal were found in 3 and 6 (65-69%) module, below estimated values for model (>82%). BOD removal effectiveness is low but the model can be applied for FC removal.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Impactos ambientales de lagunas de estabilización de la capital de Catamarca

El manejo deficiente de efluentes cloacales origina grandes problemas ambientales. Las lagunas de estabilización de aguas residuales presentan impactos al medio ambiente, cuya importancia y magnitud deben ser analizadas bajo las condiciones de cada proyecto. El objetivo de este trabajo es determinar los posibles impactos ambientales derivados del sistema de lagunas de estabilización de la ciudad Capital de Catamarca. Se identificaron las alteraciones y riesgos ambientales potenciales sobre los elementos del medio, sus variables más importantes y los efectos de las acciones implementadas en el sistema de tratamiento utilizando una matriz interactiva. En la segunda etapa, se cuantificó los efectos positivos y negativos producidos sobre el medio empleando una matriz cuantitativa. El sistema de tratamiento de efluentes produce el 66,19 % de impactos positivos y el 34,81 % de negativos. El control operativo del mismo, junto a un servicio de vigilancia y monitoreo ambiental podrán mitigar la mayoría de los impactos negativos.An inadequate management of sewage effluents can cause serious environmental problems. Waste water stabilization ponds show environmental impact which should be analysed according to each project conditions. The objective of this study is to determine the probable environmental problems derived from the stabilization ponds system in the capital city of Catamarca. Changes and potential risks of the environment were identified as well as the most important variables and effects of the actions taken for the treatment system using an interactive matrix. During the second stage, the positive and negative effects on the environment were quantified with a quantitative matrix. The treatment system produced a 66.19% positive impact and a 34.81% negative impact. The operational control of the same as well as an environment monitoring system could relieve the negative impact.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Additive Manufacturing of 3D Printed Microwave Passive Components

This chapter presents a comprehensive analysis of the applications of a low-cost version of additive manufacturing (AM). The technique called Fused Filament Fabrication (FFF), which makes use of plastic as raw material, is explained in the context of its applications to the microwave waveguide engineering field. The main advantages of this technology include the promptness to print models, the variety of feasible geometries, and specially the reduced cost. The main limitations are also explained. Two important applications are considered: (1) rapid prototyping of complex devices and (2) manufacturing of fully functional devices. The former is relevant to get a more realistic perspective of the actual geometry in computer-aided designs, as shown in several examples. It also helps to forecast possible issues in the fabrication process that the computer sometimes fails to detect at the design stage. In the latter case (2), the subsequent and necessary metallization of plastic devices is also addressed. Several examples of state-of-the-art passive waveguide devices are presented, including waveguide filters, a diplexer, a branch-line coupler, a load or horn antennas, which have been printed, metallized, and measured. The results show the potential of three-dimensional (3D) printing and provide a different insight into this innovative technology

SanAntonioApp: visualização interativa e repositório de curvas de duração de vazão espacialmente distribuídas do arroio San Antonio - Uruguai

Agricultural irrigation projects require information on the quantity and frequency of streamflow to design irrigation systems. On the one hand, this information is obtained from gauging stations or hydrologic models. On the other hand, there are few gauging stations, and hydrologic models are expensive to implement, especially for small irrigation projects. This work proposes a method for estimating spatially distributed Flow Duration Curves (FDC), and describes the SanAntonioApp interactive application with open access and repository, which is used to share the results of this work. The proposed framework uses three years of records of a rich hydrometeorological network to implement, optimise and cross-validate the WFLOW-HBV distributed hydrologic model in San Antonio Creek (Salto, Uruguay). Then, FDC are generated by extending the simulation period with the long records of an agro-climatological station (30 years). The results of this work contribute to evaluate the water availability of the San Antonio catchment and provide information on how often this availability is guaranteed. In addition, the application allows estimating the probability of exceedance of the daily streamflow for a given month and location. This function could be used to estimate the environmental flow established in the current water regulation in Uruguay.Los proyectos de riego necesitan información sobre la cantidad y la frecuencia del caudal de los ríos para el diseño y el dimensionamiento del sistema de riego. Por un lado, esta información se obtiene a través de estaciones de aforo o modelos hidrológicos. Por otro lado, las estaciones de aforo son escasas y la implementación de modelos hidrológicos es costosa, especialmente para proyectos de riego pequeños. Este trabajo propone una metodología para estimar las curvas de duración de caudales (FDC, por sus siglas en inglés) espacialmente distribuidas, y describe la aplicación interactiva y el repositorio de acceso abierto SanAntonioApp, que es utilizado para compartir los resultados de esta investigación. El marco propuesto utiliza tres años de registros de una red hidrometeorológica densa para implementar, optimizar y validar de forma cruzada el modelo hidrológico distribuido WFLOW-HBV en el arroyo San Antonio (Salto, Uruguay). Luego, las FDC se generan extendiendo el período de simulación con una estación agroclimatológica de largo registro (30 años). Los resultados de este trabajo ayudan a evaluar la disponibilidad de agua de la cuenca de San Antonio y brindan información sobre la frecuencia con la que se garantiza esa disponibilidad. Además, la aplicación permite estimar la probabilidad de excedencia del caudal diario para un mes y el sitio determinado. Esta característica podría usarse para estimar el caudal ambiental definido por la actual regulación de usos de aguas públicas de Uruguay.Os projetos de irrigação precisam de informações sobre a quantidade e frequência da vazão do rio para o projeto e dimensionamento do sistema de irrigação. Por um lado, essas informações são obtidas por meio de estações hidrográficas ou modelos hidrológicos. Por outro lado, as estações hidrográficas são escassas e a implementação de modelos hidrológicos é cara, principalmente para pequenos projetos de irrigação. Este trabalho propõe uma metodologia para estimar curvas de permanência de vazão espacialmente distribuídas (FDC, por sua sigla em inglês) e descreve a aplicação interativa e o repositório de acesso aberto SanAntonioApp, que é utilizado para compartilhar os resultados desta pesquisa. A estrutura proposta usa 3 anos de registros de uma rede hidrometeorológica densa para implementar, otimizar e validar o modelo hidrológico distribuído WFLOW-HBV no arroio San Antonio (Salto - Uruguai). Em seguida, os FDCs são gerados estendendo o período de simulação com uma estação agroclimatológica com uma longa série de dados (30 anos). Os resultados deste trabalho ajudam a avaliar a disponibilidade de água na bacia de San Antonio e fornecem informações sobre a frequência com que essa disponibilidade é garantida. Além disso, o aplicativo permite estimar a probabilidade de superação da vazão diária para um determinado mês e local. Esta característica poderia ser usada para estimar a vazão ambiental definida pela atual regulamentação do uso público da água no Uruguai