Remote Sensing Evaluation Drone Herbicide Application Effectiveness for Controlling Echinochloa spp. in Rice Crop in Valencia (Spain).

Rice (Oryza sativa L.) is a staple cereal in the diet of more than half of the world's population. Within the European Union, Spain is a leader in rice production due to its climate and tradition, accounting for 26% of total EU production in 2020. The Valencian rice area covers around 15,000 hectares and is strongly influenced by biotic and abiotic factors. An important biotic factor affecting rice production is weeds, which compete with rice for sunlight, water and nutrients. The dominant weed in Spain is Echinochloa spp., although wild rice is becoming increasingly important. Rice cultivation in Valencia takes place in the area of L'Albufera de Valencia, which is a natural park, i.e., a special protection area. In this natural area, the use of phytosanitary products is limited, so it is necessary to use the minimum amount possible. Therefore, the objective of this work is to evaluate the possibility of using remote sensing effectively to determine the effectiveness of the application of the herbicide cyhalofop-butyl by drone for the control of Echinochloa spp. in rice crops in Valencia. The results will be compared with those obtained by using sterilisation machines (electric backpack sprayers) to apply the herbicide. To evaluate the effectiveness of the application, the reflectance obtained by the satellite sensors in the red and near infrared (NIR) wavelengths, as well as the normalised difference vegetation index (NDVI), were used. The remote sensing results were analysed and complemented by the number of rice plants and weeds per area, plant dry weight, leaf area, BBCH phenological state, SPAD index values, chlorophyll content and relative growth rate. Remote sensing is validated as an effective tool for determining the efficacy of an herbicide in controlling weeds applied by both the drone and the electric backpack sprayer. The weeds slowed down their development after the treatment. Depending on the phenological state of the crop and the active ingredient of the herbicide, these results are applicable to other areas with different climatic and environmental conditions.

Bifocal Ultrasound Focusing Using Bi-Fresnel Zone Plate Lenses.

In this work, we present a bifocal Fresnel zone plate (BiFZP) capable of generating focusing profiles with two different foci. The performance of the BiFZP is demonstrated in the ultrasound domain, with a very good agreement between the experimental measurements and the finite element method (FEM) simulations. This lens becomes an appealing alternative to other dual-focusing lenses, in which the foci location can only be set at a limited range of positions, such as M-bonacci zone plates. Moreover, the variation of the operating frequency has also been analyzed, providing an additional dynamic control parameter in this type of lenses.

Transient Analysis of Fresnel Zone Plates for Ultrasound Focusing Applications.

Fresnel Zone Plates are planar lenses that can be used to focus ultrasound beams. This kind of acoustic lenses can play a key role in the resolution of ultrasonic NDT systems. In this type of pulse-echo applications, the pulse duration is an important parameter that specifies the axial resolution, and thus, shorter ultrasound pulses provide higher resolutions. However, acoustic lenses exhibit a transient response that should be considered when setting the pulse duration, as pulses shorter than the transient state duration result in degradation in the response of acoustic lenses in terms of focal intensity, focal displacement, and lateral and axial resolutions. In this work, a thorough analysis of the transient response of Fresnel Zone Plates is discussed, demonstrating that the transient state should be considered in order to achieve optimal focusing performance. Theoretical and numerical results are presented, showing very good agreement.

Phase Method for Visualization of Hidden Dielectric Objects in the Millimeter Waveband.

A method of detecting dielectric objects hidden behind an opaque barrier located on a reflective background, based on the distortion of interference fringes, is proposed in this article. Experiments conducted in the millimeter wavelength range demonstrated the effectiveness of the method under consideration, which does not require a holographic image reconstruction. Such a system can be classified as contour imaging.

Design of Acoustical Bessel-Like Beam Formation by a Pupil Masked Soret Zone Plate Lens.

The image performance of acoustic and ultrasound sensors depends on several fundamental parameters such as depth of focus or lateral resolution. There are currently two different types of acoustic diffractive lenses: those that form a diffraction-limited spot with a shallow depth of focus (zone plates) and lenses that form an extended focus (quasi-Bessel beams). In this paper, we investigate a pupil-masked Soret zone plate, which allows the tunability of a normalized angular spectrum. It is shown that the depth of focus and the lateral resolution can be modified, without changing the lens structure, by choosing the size of the pupil mask. This effect is based on the transformation of spherically-converging waves into quasi-conical waves, due to the apodization of the central part of the zone plate. The theoretical analysis is verified with both numerical simulations and experimental measurements. A Soret zone plate immersed in water with D/2F = 2.5 and F = 4.5 λ changes its depth of focus from 2.84 λ to 5.9 λ and the lateral resolution increases from 0.81 λ to 0.64 λ at a frequency of 250 kHz, by modifying the pupil mask dimensions of the Soret zone plate.

Design of Binary-Sequence Zone Plates in High Wavelength Domains.

The design of zone plates is an important topic in many areas of physics, such as optics, X-rays, microwaves or ultrasonics. In this paper, a zone plate design method, which provides high flexibility in the shaping of the focusing profile, is analyzed. This flexibility is achieved through the use of binary sequences that produce zone plates with different properties and applications. It is shown that this binary-sequence method works properly at low wavelengths, but requires a modification term to work accurately in high wavelength domains. This additional term extends this powerful design method to any wavelength. Simulation results show acoustic focusing profiles for Fresnel, Fibonacci and Cantor zone plates operating at a wavelength of 1.5 mm without any distortion.

Analysis of Fresnel Zone Plates Focusing Dependence on Operating Frequency.

The focusing properties of Fresnel Zone Plates (FZPs) against frequency are analyzed in this work. It is shown that the FZP focal length depends almost linearly on the operating frequency. Focal depth and focal distortion are also considered, establishing a limit on the frequency span at which the operating frequency can be shifted. An underwater FZP ultrasound focusing system is demonstrated, and experimental results agree with the theoretical analysis and simulations.

Pinhole Zone Plate Lens for Ultrasound Focusing.

The focusing capabilities of a pinhole zone plate lens are presented and compared with those of a conventional Fresnel zone plate lens. The focusing properties are examined both experimentally and numerically. The results confirm that a pinhole zone plate lens can be an alternative to a Fresnel lens. A smooth filtering effect is created in pinhole zone plate lenses, giving rise to a reduction of the side lobes around the principal focus associated with the conventional Fresnel zone plate lens. The manufacturing technique of the pinhole zone plate lens allows the designing and constructing of lenses for different focal lengths quickly and economically and without the need to drill new plates.

[Workplace violence in Latin America: A review of the scientific evidence]. / Violencia laboral en América Latina: una revisión de la evidencia científica.

INTRODUCTION: Workplace Violence has acquired social relevance given the evidence regarding there its health consequences. Has identified various effects such as mood disorders and sleep disorders, hostility, isolation, insecurity, among others. OBJECTIVE: To describe and analyze scientific evidence published on workplace violence in studies in Latin American countries between 2009 and 2014. MATERIALS AND METHODS: A descriptive and quantitative study. A search was made on the basis of Academic Search Complete (EBSCOhost) Academic Source Premier, PSICODOC, Scielo.org, JSTOR and SCOPUS. And indexed empirical studies were considered. RESULTS: We worked with 46 selected articles. The studies showed a higher amount of psychological violence at work, with a potential risk in women and health professionals. Also, the analysis categories were the most reported behaviors that express violence, health implications and facilitators. CONCLUSIONS: The literature on the study of workplace violence in Latin America is recent. Items are descriptive, interpretative studies with insufficient or analytical nature. Health personnel, particularly women, have conditions of vulnerability, with relevance with regard to sexual harassment, wage inequality and bullying.

Ultrasonic lens based on a subwavelength slit surrounded by grooves.

The lensing capabilities of a single subwavelength slit surrounded by a finite array of grooves milled into a brass plate is presented. The modulation of the beam intensity of this ultrasonic lens can be adjusted by varying the groove depth. Numerical simulations as well as experimental validations at 290 kHz are shown. The experimental results are in good agreement with the numerical simulations. This system is believed to have potential applications for medical ultrasound fields such as tomography and therapy.

Ultrasonic focusing with mesoscale polymer cuboid.

In this paper, we demonstrate that, contrary to what the Geometrical Optics laws dictate, a flat polymer mesoscale cuboid immersed in water with no need of negative refraction can focus sound. Two main polymers were considered and lens parameters compared: PMMA and Rexolite®. It was concluded that Rexolite® is preferable for acoustic jet formation. The nature of the formation of the foci along the longitudinal axis, that is to say along the wave propagation axis, is numerically and experimentally demonstrated. In addition, the conditions under which a cubic particles lens of this type forms a single localized region with a sub-diffraction transverse size (approximately 0.44 wavelength) are determined. The comparisons of the acoustic wave pressures and the focal distance between the Finite Element Method based numerical results and the experimental results show fair agreement.

Cylindrical 3D printed configurable ultrasonic lens for subwavelength focusing enhancement.

In this study, we report the characteristics of acoustic jets obtained through a mesoscale (radius less than 5 wavelengths) ABS cylinder made with a 3D printer. We have analyzed the influence of cylinder size on the characteristic parameters of an acoustic jet, such as maximum acoustic intensity at focus, Full Width at Half Maximum and length of Acoustic Jet. FWHM below 0.5 wavelength in AJ was experimentally obtained. It has been observed that there are two operating regimes depending on the cylinder radius: the resonant and the non-resonant. In the resonant regime, the excitation of Whispering Gallery Modes results in optimal parameter values of the acoustic jet. However, as it is a resonant regime, any minimal variation in cylinder size, working frequency or refractive index would make resonance disappear. In non-resonant mode, a phononic crystal has been embedded inside the cylinder and the characteristic parameters of the acoustic jet have been studied. These have been observed to improve. Finally, we have shown that curved acoustic jets can be obtained with the ABS cylinder with a phononic crystal embedded inside.

Fractal lenses based on Cantor binary sequences for ultrasound focusing applications.

In this work, we demonstrate the application of Cantor fractal lenses in acoustics. The Cantor Zone Plate (CZP), previously introduced in optics, is designed from a conventional Fresnel Zone Plate (FZP) using a binary sequence governed by the distribution of a generalized Cantor set. The CZP maintains its main focus at the same focal distance than its associated FZP, providing a softer multi-foci focusing profile which is very useful in certain ultrasound therapeutic applications. Experimental measurements are in good agreement with the theoretical model, demonstrating that CZPs are suitable for the ultrasound field.

Acoustic Focusing Enhancement In Fresnel Zone Plate Lenses.

The development of flat acoustic lenses for different applications such as biomedical engineering is a topic of great interest. Flat lenses like Fresnel Zone Plates (FZPs) are capable of focusing energy beams without the need of concave or convex geometries, which are more difficult to manufacture. One of the possible applications of these type of lenses is tumor ablation through High Intensity Focused Ultrasound (HIFU) therapies with real time Magnetic Resonance Imaging (MRI) monitoring. In order to be MRI compatible, the FZP material cannot have electromagnetic interaction. In this work, a Phase-Reversal FZP (PR-FZP) made of Polylactic Acid (PLA) manufactured with a commercial 3D printer is proposed as a better, more efficient and MRI compatible alternative to conventional Soret FZPs. Phase-Reversal lenses, unlike traditional FZPs, take advantage of all the incident energy by adding phase compensation regions instead of pressure blocking regions. The manufactured PR-FZP achieves 21.9 dB of focal gain, which increases the gain compared to a Soret FZP of its same size by a factor of 4.0 dB. Both numerical and experimental results are presented, demonstrating the improved focusing capabilities of these types of lenses.

Observation of ultrasonic Talbot effect in perforated plates.

The Talbot effect using ultrasonic waves transmitted through a periodic perforated plate is presented. The ultrasonic wave-field at the exit of the perforated plate replicates the perforated pattern at the Talbot distance. Experimental results are validated by an analytical model. The measured propagating wave-field is consistent with the analytical results. The influence of the grating size and the filling fraction on the Talbot effect are also studied, and it is found that both parameters affect the formation of Talbot images.

Manipulation of focal patterns in acoustic Soret type zone plate lens by using reference radius/phase effect.

The manipulation of focal patterns of acoustic underwater Soret Zone Plate lens in far fields, such as manipulation (optimization) of Sidelobe Level and the design of long depth of focus by selecting the simple free parameter called reference radius (phase) has been demonstrated.Two effects have been studied by means of numerical simulations. Regarding the first effect, simulations demonstrate diffraction limited focal spot (0.47 wavelength) and 3 dB reduction of the first Side Lobe Level using Soret ZP with an optimal reference radius and without causing neither main lobe broadening or gain reduction. In the second effect, by using numerical simulations an increasing of depth of focus, more than 2 times, in comparison with classical Soret ZP with high numerical aperture (F/D = 2.5), was observed.

Trayectorias activistas de mujeres mayores en el chile postdictadura / Trajetórias ativistas de mulheres idosas na pós-ditadura do chile / Activist trajectories of older women in post-dictatorship chile

Resumen: La vejez de las mujeres mayores suele ser descrita como una etapa en la que se vivencian múltiples cambios y pérdidas, donde se acrecientan las discriminaciones de género. Sin embargo, poco se ha explorado la experiencia biográfica al envejecer. En este artículo, identificamos como construyen narrativamente trayectorias de acción política mujeres mayores activistas de la Agrupación Bordadoras por la Memoria de la ciudad de Valparaíso-Chile. Realizamos un estudio cualitativo con entrevistas biográficas siguiendo la propuesta de relatos de vida. Sus itinerarios biográficos dan cuenta de un continuum en su acción política y un cuestionamiento al sistema neoliberal. Por medio de sus bordados, contribuyen a la lucha por la memoria y la justicia social. Resignifican su activismo en la vejez, incluyendo nuevos repertorios de acción y proyectos, mediante prácticas de sororidad. Concluimos la importancia de disputar la vejez desde el ciclo vital convencional, dando cabida a trayectorias femeninas agencializadas.

Resumo: A velhice das mulheres idosas é muitas vezes descrita como uma época de múltiplas mudanças, perda e maior discriminação de género. No entanto, pouco tem sido explorado sobre a experiência biográfica do envelhecimento. Neste artigo, identificamos como as mulheres ativistas mais velhas da "Agrupación Bordadoras por la Memoria" na cidade de Valparaíso-Chile constroem trajetórias narrativas de ação política. Realizámos um estudo qualitativo com entrevistas biográficas na sequência da proposta de narrativas de vida. Os seus itinerários biográficos mostram uma continuidade na sua ação política e um questionamento do sistema neoliberal. Através dos seus bordados, elas contribuem para a luta pela memória e justiça social. Dão novo significado ao seu ativismo na velhice, incluindo novos repertórios de ação e projetos, através de práticas de irmandade. Concluímos que é importante contestar a velhice do ciclo de vida convencional, criando espaço para trajetórias femininas agencializadas.

Abstract: Old age among older women is usually described as a stage in which multiple changes, losses and gender discrimination are experienced. However, little has been explored about the biographical experience of aging. In this article, we identify how older women activists of the Agrupación Bordadoras por la Memoria in the city of Valparaíso, Chile, narratively construct trajectories of political action. We conducted a qualitative study with biographical interviews following proposal of life narratives. Their biographical itineraries show a continuum in their political action and a questioning of the neoliberal system. Through their embroideries, they contribute to the struggle for memory and social justice. They re-signify their activism in old age, including new repertoires of action and projects, through practices of sorority. We conclude the importance of disputing old age from the conventional life cycle, making room for agentialized feminine trajectories.

Experimental Ultrasound Transmission through Fluid-Solid and Air-Solid Phononic Plates.

Underwater ultrasonic transmissions for fluid-solid and air-solid phononic brass plates are reported in this work. Although the structure is roughly the same, experimental results show very different behaviour between fluid-solid and air-solid phononic plates, due to most of the properties of the fluid-solid perforated plates rely on Fabry-Perot resonances, Wood anomalies and Lamb modes. In air-solid phononic plates Fabry-Perot resonance is highly attenuated due to impedances difference between air and water, and therefore some transmission modes are now distinguishable due to surface modes coupling.

Factores facilitadores de la violencia laboral: una revisión de la evidencia científica en América Latina / Enabling factors of workplace violence: a review of the scientific evidence in Latin America

En el presente artículo se dan a conocer los resultados de una revisión sistemática de la literatura que reporta investigaciones en poblaciones latinoamericanas en torno a factores facilitadores de la violencia laboral. Para esto se realizó una búsqueda en las bases de Academic Search Complete (EBSCOhost), Fuente Académica Premier, PSICODOC, Scielo.org, JSTOR y SCOPUS. Se contemplaron estudios empíricos e indexados entre los años 2009 y 2014. Se trabajó con una selección de 17 artículos y se generaron cuatro categorías de análisis cualitativo: 1. Aproximación metodológica de los estudios. 2. Factores determinantes individuales. 3. Factores determinantes sociales-interpersonales. 4. Factores determinantes organizacionales. A partir del análisis se concluye que la violencia en el trabajo tiene un carácter multideterminado, transversal y multicausal, por lo cual debe existir una perspectiva sistémica para su abordaje, con el fin de abarcar toda su complejidad y profundidad.

This article discloses the results of a systematic review of the literature reporting research in Latin American populations around facilitating factors of workplace violence. For this, a search was conducted on the bases of Academic Search Complete (EBSCOhost) Academic Source Premier, PSICODOC, Scielo.org, JSTOR and Scopus. Empirical studies were contemplated and indexed between 2009 and 2014. We worked with a selection of 17 articles, and four categories of qualitative analysis were generated: 1. Methodological approach of the studies. 2. Individual determinants. 3. social-interpersonal determinants. 4. organizational determinants. The analysis concluded that violence at work has a multi-determined, transversal and multi-causal character, so there must be a systemic perspective to address them, in order to cover all its complexity and depth.

Significados discursivos de trabajadoras de organismos públicos chilenos y sus implicancias en la salud mental / Discursive meaning of Chilean public sector women workers and implications for mental health

Las mujeres trabajadoras del sector público en Chile son el colectivo que tiene mayor prevalencia de problemas de salud mental. El propósito de este artículo consiste en dar a conocer la percepción de mujeres trabajadoras del Estado chileno respecto a la relación entre sus condiciones laborales y su salud mental. El estudio fue descriptivo y de carácter cualitativo, a partir de la epistemología feminista. Se realizaron entrevistas abiertas a 15 mujeres de clase media, cuyas condiciones de trabajo en organismos públicos contemplaran modalidades flexibles. Se utilizó análisis de contenido cualitativo y los datos fueron codificados a través del programa computacional ATLAS.ti. Los resultados fueron agrupados en las categorías Vinculación laboral flexible e incertidumbre; Desprotección de salud y precarización laboral; y Malestar subjetivo, evidenciando que tanto las trabajadoras con convenio a honorarios como aquellas a contrata experimentaban incertidumbre vinculada a una vivencia de estrés permanente, ansiedad, cansancio emocional, desprotección y precarización laboral, lo que se traducía en sufrimiento psíquico. Se concluye que los problemas en la salud mental de trabajadoras del Estado no son sino la expresión de un malestar social asociado a la vivencia y percepción de desigualdades sociales y de género. La tendencia a individualizar este conflicto social responde a una falta de regulación del Estado en relación a la salud mental, el trabajo y el género(AU)

Public sector women workers in Chile are the group with the highest prevalence of mental health problems.We examined the perspectives of these women workers on the relationship between working conditions and mental health. The study was descriptive and qualitative, based on a feminist epistemology. Open interviews were conducted with 15 middle-class public sector women whose working conditions allowed the incorporation of flexible modalities. Qualitative content analysis was used and the data were coded using ATLAS.ti. Results where grouped into the following categories : flexible work and job insecurity; uncovered healthcare and labor precariousness; and subjective discomfort. This showed that both hourly and salaried workerswere experiencing uncertainty, linked to on going stress, anxiety, emotional exhaustion, job insecurity and vulnerability, all of which resulted in psychological distress. We conclude that mental health issues among public sector workers are an expression of social unrest associated with the experience and perception of social and gender inequalities. The tendency to individualize this social conflict results from a lack of state regulation in relation to mental health, work and gender(AU)