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The cleaning robots are going through some significant development in recent years, driven by the greater market penetration and the demand for better cleaning performance. However, most of the robots have problems covering the total cleaning area given geometric limitations of the platforms in relation to the cleaning stage, given furniture and architecture. In this paper, we describe the hTrihex platform, which is a self-reconfigurable adaptive robot that attains three different configurations. The change in configuration gives rise to variation in the kinematic model, which in turn changes the behavior of robot locomotion. The change in configuration and the robot position is evaluated using the measurements from the on-board sensors like the encoders, LIDAR, and inertial measuring unit (IMU). These data are then utilized to develop a new cascade control strategy for motion control of h-Trihex. The control cascade comprises of a robust backstepping controller in the outer loop for tackling the varying kinematic and a conventional PID in the inner loop for speed control. This cascade is appended by a PID controller, for correcting the wheel orientation after each configuration change. The proposed design assures asymptotic path tracking and satisfactory closed-loop performance, which are validated through numerical simulations and experiments.

Nature has always been an inspiration for engineers and designers to have technological inventions. The postures, locomotion and gait cycles of animals are usually smooth, dynamically stable, and highly adaptable in an unknown terrain. Based on a giraffe's leg folding pattern, we develop a quadruped hybrid drain mapping robot with modular sub-systems, four bar inversion mechanism based legs and bi-directional rolling wheel, named, Tarantula-II. The platform undergoes self-reconfiguration and achieves variable height and width, which in turn helps in navigation in a drain with multiple level-shifts. This paper describes the key features of giraffe's limb, how the folding pattern of the limbs are implemented in the robot design. In addition, we discuss the detailed mechanical design of platform, the kinematics analysis of each leg, kinematics of the platform with respect to wheels, and structural analysis of the platform under different gait condition. Applying the kinematics formulation and posture correction algorithm, we verify the mobility and level shifting capability of the platform both in lab setting and drain environment.

Signals of opportunity (SoOp) reflectometry (SoOp-R) is a maturing field for geophysical remote sensing as evidenced by the growing number of airborne and spaceborne experiments. As this approach receives more attention, it is worth analyzing SoOp-R's capabilities to retrieve subsurface soil moisture (SM) by leveraging communication and navigation satellite transmitters. In this research, the Cramer-Rao lower bound (CRLB) is used to identify the effects of variable SoOp-R parameters on the best achievable estimation error for root-zone soil moisture (RZSM). This study investigates the use of multiple frequency, polarization, and incidence angle measurement configurations on a two-layered dielectric profile. The results also detail the effects of variable SM conditions on the capability of SoOp-R systems to predict subsurface SM. The most prevalent observation is the importance of using at least two frequencies to limit uncertainties from subsurface SM estimates. If at least two frequencies are used, the CRLB of a profile is retrievable within the root-zone depending on the surface SM content as well as the number of independent measurements of the profile. For a depth of 30 cm, it is observed that a CRLB corresponding to 4% RZSM estimation accuracy is achievable with as few as two dual-frequency-based SoOp-R measurements. For this depth, increasing number of measurements provided by polarization and incidence angle allow for sensing of increasingly wet SM profile structures. This study, overall, details a methodology by which SoOp-R receiver system can be designed to achieve a desired CRLB using a tradeoff study between the available measurements and SM profile.

Glass-façade-cleaning robots are an emerging class of service robots. This kind of cleaning robot is designed to operate on vertical surfaces, for which tracking the position and orientation becomes more challenging. In this article, we have presented a glass-façade-cleaning robot, Mantis v2, who can shift from one window panel to another like any other in the market. Due to the complexity of the panel shifting, we proposed and evaluated different methods for estimating its orientation using different kinds of sensors working together on the Robot Operating System (ROS). For this application, we used an onboard Inertial Measurement Unit (IMU), wheel encoders, a beacon-based system, Time-of-Flight (ToF) range sensors, and an external vision sensor (camera) for angular position estimation of the Mantis v2 robot. The external camera is used to monitor the robot’s operation and to track the coordinates of two colored markers attached along the longitudinal axis of the robot to estimate its orientation angle. ToF lidar sensors are attached on both sides of the robot to detect the window frame. ToF sensors are used for calculating the distance to the window frame; differences between beam readings are used to calculate the orientation angle of the robot. Differential drive wheel encoder data are used to estimate the robot’s heading angle on a 2D façade surface. An integrated heading angle estimation is also provided by using simple fusion techniques, i.e., a complementary filter (CF) and 1D Kalman filter (KF) utilizing the IMU sensor’s raw data. The heading angle information provided by different sensory systems is then evaluated in static and dynamic tests against an off-the-shelf attitude and heading reference system (AHRS). It is observed that ToF sensors work effectively from 0 to 30 degrees, beacons have a delay up to five seconds, and the odometry error increases according to the navigation distance due to slippage and/or sliding on the glass. Among all tested orientation sensors and methods, the vision sensor scheme proved to be better, with an orientation angle error of less than 0.8 degrees for this application. The experimental results demonstrate the efficacy of our proposed techniques in this orientation tracking, which has never applied in this specific application of cleaning robots.

Wall cleaning robots are developed to cater to the demands of the building maintenance sector. The ability to climb vertical surfaces is one of the crucial requirements of a wall cleaning robot. Robots that can climb vertical surfaces by adhesion to a surface are preferred since those do not require additional support structures. Vacuum suction mechanisms are widely used in this regard. The suction force acting on the robot due to the negative pressure built up is used by these robots for the adhesion. A robot will fall off or overturn when the pressure difference drops down a certain threshold. In contrast, if the pressure difference becomes too high, the excessive amount of frictional forces will hinder the locomotion ability. Moreover, a wall cleaning robot should be capable of adapting the adhesion force to maintain the symmetry between safe adhesion and reliable locomotion since adhesion forces which are too low or too high hinder the safety of adhesion and reliability of locomotion respectively. Thus, the pressure difference needs to be sustained within a desired range to ensure a robot’s safety and reliability. However, the pressure difference built up by a vacuum system may unpredictably vary due to unexpected variation of air leakages due to irregularities in surfaces. The existing wall cleaning robots that use vacuum suction mechanisms for adhesion are not aware of the adhesion status, or subsequently responding to them. Therefore, this paper proposes a design for a wall cleaning robot that is capable of adapting vacuum power based on the adhesion-awareness to improve safety and reliability. A fuzzy inference system is proposed here to adapt the vacuum power based on the variation of the adhesion and the present power setting of the vacuum. Moreover, an application of fuzzy logic to produce a novel controlling criterion for a wall cleaning robot to ensure safety and reliability of operation is proposed. A fuzzy inference system was used to achieve the control goals, since the exact underlying dynamics of the vacuum-adhesion cannot be mathematically modeled. The design details of the robot are presented with due attention to the proposed control strategy. Experimental results confirmed that the performance of a robot with proposed adhesion-awareness surpasses that of a robot with no adhesion-awareness in the aspects of safety, reliability, and efficiency. The limitations of the work and future design suggestions are also discussed.

The autonomous floor-cleaning self-reconfigurable robots have entered into the practical stage by establishing enhanced area coverage over the fixed morphology counterparts. Energy consumption during the self-reconfiguration, i.e., changing the shape of the robot from one form to another, becomes a primary focus in these robots that carry finite energy sources. In this paper, hTetro platform with two hinge dissections namely, Left−Left−Left (LLL) and Left−Left−Right (LLR) are modeled and assessed for the energy consumption during the reconfiguration. The geometry of the two dissections, its workspaces, and the set of inverse kinematics solutions for the seven forms are presented. The inverse dynamics using the Newton−Euler approach was adopted to calculate the wrench, i.e., forces and moments at the hinge joints, and subsequently assess the power consumed during the reconfigurations of two hinge dissections in the simulation. Extensive experiments were performed across the two assembled platforms to estimate the power consumption by logging the current data. The comparison was made with the simulation results. The results are particularly useful in the selection of reconfiguration with minimal energy consumption during the floor cleaning.

Abstract Paspalum notatum Flüggé is an economically important subtropical fodder grass that is widely used in the Americas. Here, we report a new chromosome-scale genome assembly and annotation of a diploid biotype collected in the center of origin of the species. Using Oxford Nanopore long reads, we generated a 557.81 Mb genome assembly (N50 = 56.1 Mb) with high gene completeness (BUSCO = 98.73%). Genome annotation identified 320 Mb (57.86%) of repetitive elements and 45,074 gene models, of which 36,079 have a high level of confidence. Further characterisation included the identification of 59 miRNA precursors together with their putative targets. The present work provides a comprehensive genomic resource for P. notatum improvement and a reference frame for functional and evolutionary research within the genus.

El presente artículo busca contribuir al desarrollo y consolidación de los estudios sobre la gourmetización y la gentrificación alimentaria, enfatizando los efectos que estos procesos tienen en ámbitos que exceden a la vida urbana. En ese marco, se propone recuperar los engranajes de la cadena de valor y sus localizaciones –desde los barrios gentrificados hasta las comunidades rurales agrícolas–, indicando los procesos de valorización y desvalorización y cómo estos afectan de forma desigual a los actores involucrados. Se enfatiza sobre este punto, estableciendo un diálogo interdisciplinar. A partir de una revisión bibliográfica, el artículo se basa en cuatro casos que se recuperan de fuentes secundarias y que ilustran la forma en la que operan estos procesos en distintos niveles, territorios y escalas: el café de autor en cuanto símbolo de distinción en los barrios gentrificados; la palta o aguacate a partir de su manifestación gastronómica en el avocado toast; el vino, desde la turistificación de su producción hasta las estrategias de valorización en su consumo urbano; y la quinoa desde el patentamiento de nuevas variedades hasta el desarrollo de mercados expulsivos de amplios sectores de población. Se concluye que el auge de estos alimentos tiene efectos de acumulación del capital por desposesión en los ámbitos rural y urbano al igual que en los procesos de producción y de consumo.

Se trabajó con escolares de cuarto y quinto de secundaria, procedentes de clase media baja de cuatro centros educativos pertenecientes al cono este y norte para analizar las características de identidad en sus niveles: nacional, generacional, regional, de género, familiar y personal. Para la recolección de datos se elaboró un instrumento basado en el inventario de identidad de Zavalloni que establece la relación entre la conciencia subjetiva y los atributos sociales objetivos, las respuestas de los sujetos fueron codificadas con sus respectivas frecuencias y clasificadas en función de su orientación positiva, negativa o neutra, finalmente las respuestas positivas y negativas fueron clasificadas en cinco categorías: instrumentales, afectivas, sociales, morales y políticas. Los resultados indicaron la presencia predominante de las respuestas instrumentales y la orientación positiva de las respuestas en cada uno de los niveles, siendo más evidentes las referidas a la identidad generacional y familiar.

En procesos de molienda de materiales abrasivos, cuya dureza sea mayor que la de los carburos cementíticos, es frecuente utilizar fundiciones aleadas de alto cromo. Estas, además del buen comportamiento a la abrasión, añaden buena resistencia a la corrosión. Las condiciones de comportamiento en servicio dependen de las microestructuras. Estas, vienen dadas por la composición, y por la modo de solidificación y tratamientos térmicos. En este trabajo, se busca, de modo experimental, observar el comportamiento de cuerpos moledores con variantes en la cantidad de Cromo, en el tratamiento térmico, y bajo condiciones variable: solo corrosión, y abrasión mas corrosión. Se observa el papel preponderante del porcentaje de Cromo, así como la dureza de los elementos moledores. Los ensayos se realizaron en un tambor giratorio simulando los molinos industriales. Estos ensayos permitieron establecer algunos parámetros de comportamiento frente a los niveles de desgaste en la molienda de piedra caliza húmeda para la fabricación de cemento Portland.

La interferencia de tallado, también conocida como penetración del perfil, es un fenómeno que puede presentarse en la generación de engranajes de perfil de evolvente con números de dientes reducidos. El resultado es un diente debilitado en su base, y por tanto con menor capacidad de transmisión desde el punto de vista de la resistencia a la flexión. No obstante, el hecho de que el diente vea disminuida su capacidad de transmisión no significa que quede inutilizado para transmitir potencia en reductores de mecanismos de minería, en especial si se tiene en cuenta que, en la inmensa mayoría de los casos, el riesgo de fallo por picadura es mucho más restrictivo que el de fallo por rotura en la base; siendo así que la penetración del perfil no tiene influencia significativa en el comportamiento a presión superficial, que origina la picadura. El presente trabajo presenta la caracterización de este fenómeno y las ecuaciones analíticas que permiten calcular el punto de intersección de las curvas que definen el perfil del diente debilitado.

La fabricación de piezas en Fundición de hierro ocupa un campo muy extenso de la industria de maquinaría. Estos materiales son aleaciones de Hierro-Carbono con altos porcentajes y que se denominan bajo el nombre de fundiciones por ser este el procedimiento industrial de fabricación de las mismas. El mayor porcentaje de Carbono hace que la temperatura de fusión de estas sea mucho menor que la de los aceros y además se logra una mayor fluidez del material líquido, lo que permite el llenado de piezas de espesores menores y de formas complicadas, es decir, tienen una mejor colabilidad. Por otra parte, la menor temperatura de fusión permite que la interacción metal – molde sea menos agresiva y en consecuencia se pueden obtener piezas más sanas.

Según sean las condiciones de dureza del material a trabajar y los esfuerzos a que esté sometida la herramienta se deberá elegir el material más adecuado para esta. Las caracterísiticas de los constituyentes permiten formular criterios de comportamiento de las herrmaientas en las diversas condiciones de trabajo.

La braquiterapia vaginal intracavitaria es frecuentemente administrada con aplicadores cilíndricos de un solo canal con fuentes HDR. El cilindro multicanal (8 canales) vaginal intracavitario permite el tratamiento preferencial de una parte de la mucosa vaginal, se se desarrolla para perfeccionar y ampliar la capacidad de la braquiterapia intracavitaria. El aplicador permite activar los canales que se entienden útiles, con longitudes variables, para irradiar volúmenes blancos de la vagina, evitando sobreirradiar las regiones sanas. Se obtiene un gradiente de dosis en la superficie del aplicador vaginal multicanal periférico favorable al tratamiento de lesiones superficiales de la mucosa vaginal, con lo que se disminuye las dosis de recto en el orden del 12 %. Se realizó este estudio con el objetivo de demostrar la utilidad del uso de aplicadores multicanales en vagina y recto, se expresaron los resultados de la construcción de aplicadores y sus característicasThe intracavitary vaginal brachytherapy is often administered using single-channel cylindrical applicators with HDR sources. The intracavitary vaginal multichannel cylinder (8 channels) allows the preferential treatment of a part of the vaginal mucosa, and it is developed to improve and to widen the intracavitary brachytherapy capacity. The applicator makes possible to activate channels considered useful, with variable lengths, to irradiate the target volumes of the vagina, avoiding the overirradiation of the healthy regions. A dose gradient is achieved in the surface of the peripheral multichannel vaginal applicator favouring the treatment of the superficial injuries of the vaginal mucosa, dropping the dose of the rectum by 12 %. This study was undertaken to demonstrate the usefulness of the multichannel applicators in the vagina and rectum. The results of the construction of applicators and their characteristics were explained

Breast cancer is the most common type of cancer in women. Although current treatments can increase patient survival, they are rarely curative when the disease is advanced (metastasis). Therefore, there is an urgent need to develop new cytotoxic drugs with a high selectivity toward cancer cells. Since repurposing approved drugs for cancer therapy has been a successful strategy in recent years, in this study, we screened a library of antiviral piperazine-derived compounds as anticancer agents. The compounds included a piperazine ring and aryl urea functions, which are privileged structures present in several anti-breast cancer drugs. The selective cytotoxic activity of a set of thirty-four 4-acyl-2-substituted piperazine urea derivatives against MCF7 breast cancer cells and MCF 10A normal breast cells was determined. Compounds 31, 32, 35, and 37 showed high selective anticancer activity against breast cancer cells and were also tested against another common type of cancer, non-small cell lung cancer (A549 lung cancer cells versus MRC-5 lung normal cells). Compounds 35 and 37 also showed selectivity against lung cancer cells. These results suggest that compounds 35 and 37 may be promising hit compounds for the development of new anticancer agents.