Search

Highlights This study analyzes the feasibility of using Artificial Neural Networks (ANNs) to estimate canopy temperatures. A methodology is introduced to forecast canopy temperatures using historical canopy temperatures. ANNs can predict canopy temperatures with satisfactory accuracy for plant stress-based irrigation scheduling. The methodology can be useful to add redundancy to plant stress-based irrigation scheduling methods. Abstract. Recent advances can provide farmers with irrigation scheduling tools based on crop stress indicators to assist in the management of Variable Rate Irrigation (VRI) center pivot systems. These tools were integrated into an Irrigation Scheduling Supervisory Control and Data Acquisition System (ISSCADAS) developed by scientists with the USDA-Agricultural Research Service (ARS). The ISSCADAS automates the collection of data from a network of wireless infrared thermometers (IRTs) distributed on a center pivot’s lateral and in the field irrigated by the center pivot, as well as data from a wireless soil water sensor network and a microclimate weather station. This study analyzes the use of Artificial Neural Networks (ANNs), a type of machine learning algorithm, for the forecasting of canopy temperatures obtained by a wireless network of IRTs mounted on a three-span VRI center pivot irrigating corn near Bushland, TX, during the summer of 2017. Among the predictors used by the ANNs were weather variables relevant to the estimation of evapotranspiration (i.e., air temperature, relative humidity, solar irradiance, and wind speed), irrigation management variables (irrigation treatment, irrigation scheduling method, and the amount of water received during the last 5 days as irrigation or rainfall), and days after planting. Two case studies were conducted using data collected from periodic scans of the field performed during the growing season by running the pivot dry. In the first case, data from the first three scans were used to train an ANN, and canopy temperatures estimated using the ANN were then compared against canopy temperatures measured by the network of IRTs during the fourth scan. In the second case, data from the first six scans were used to train ANNs, and canopy temperatures estimated using the ANN were then compared against canopy temperatures measured by the network of IRTs during the seventh scan. The Root of the Mean Squared Error (RMSE) of ANN predictions in the first case ranged from 1.04°C to 2.49°C, whereas the RMSE of ANN predictions in the second case ranged from 2.14°C to 2.77°C. To assess the impact of ANN accuracy on irrigation management, estimated canopy temperatures were fed to a plant-stress-based irrigation scheduling method, and the resulting prescription maps were compared against prescription maps obtained by the same method using the canopy temperatures measured by the network of IRTs. In the first case, no difference was found between both prescription maps. In the second case, only one plot (out of 26) was assigned a different prescription. Results of this study suggest that machine learning techniques can be used to assist the ISSCADAS in situations where canopy temperatures cannot be measured by the network of IRTs due to poor visibility conditions, or because the center pivot cannot traverse the field within a reasonable amount of time. Keywords: Artificial Neural Network, Canopy temperature sensing, Center pivot irrigation, Irrigation scheduling, Machine learning, Metamodeling, Variable rate irrigation.

Speech-language therapists and audiologists (SLTAs) may encounter difficulties when confronted with patient death and dying, which may conflict with their moral beliefs and result in moral injury. Furthermore, South African SLTAs practice in a country with a high mortality rate, which may add to the complexity of their experience. Moreover, they may be influenced by African philosophies promoting care, which might conflict with their experiences of patient death and dying.To explore the moral injury experienced by South African SLTAs in patient death and dying, and how they overcame the injury.This article forms part of a larger qualitative study that explored SLTAs' experiences of patient death and dying in South Africa. Thematic analysis was conducted on the transcripts of 25 episodic narrative interviews conducted with South African SLTAs on their experiences of patient death and dying.Findings suggest that South African SLTAs experienced helplessness, guilt and anger in patient death and dying. However, with support from the allied team, engaging in self-reflection and religious practices, they reported alleviation of moral injury.In order to mitigate moral injury in South African SLTAs, they require professional education, self-care strategies, guidelines and support from the teams in which they work and their supervisors. Research is needed that explores how SLTAs' biographical characteristics and interactions with significant others of dying and deceased patients, may result in moral injury. WHAT THIS PAPER ADDS?: What is already known on this subject? Moral injury and measures used to overcome the injury have been explored in military personnel, doctors and nurses, but not in SLTAs. However, studies that explored the perceptions of SLTs and/or audiologists regarding providing palliative care and of death and dying, particularly that by Rivers et al. in 2009, suggested that these professionals may be at risk of experiencing emotional trauma due to patient death, particularly when not receiving undergraduate education on this subject. However, the extent of this trauma and the support needed to overcome it is unknown because the participants in these studies may have not experienced patient death, and were only students or just SLTs. What this article adds? This article highlights the complexity of speech-language therapy and audiology practice when confronted with patient death and dying. South African SLTAs may have to make decisions that conflict with their morals and professional practice standards, especially as the helping nature of their profession is characterized by African philosophies that promote care, which may result in moral injury. Clinical implications of this article This article indicates that in addition to undergraduate education on patient death and dying, SLTs and audiologists require continuous professional education on this topic, self-care strategies, support from the teams in which they work, and their supervisors and guidelines for when they encounter patient death and dying.

This paper employs the Ivaldi-Vibes algorithm to model the U.S. gasoline market under the hypothetical scenario in which the ethanol production subsidies were phased out from 1995- 2005. Under this hypothetical situation, the individuals were not only willing to switch their consumption decision, but they were also willing to consider alternative modes of transportation including public transportation, biking or walking. As a result, the outside alternative market share increased about 4% and 6% and the conventional gasoline market shares increased while the ethanol blends experienced decreases across all petroleum districts. This methodology also permitted simulating the impact of this elimination on the gasoline prices. The conventional gasoline prices increased in a range between 0.12 and 1.34 percent. Finally, since different types of oxygenates are blended with the regular gasoline to compliance the EPA regulations, the reduction in the reformulated gasoline market shares implied a trade off in the demand for these oxygenates whose variation rates averaged 55.14% for the ethanol-MTBE ratio. En este trabajo se emplea el algoritmo de Ivaldi-Vibes para modelar el mercado de combustibles de EE.UU. bajo el escenario hipotético en el que los subsidios a la producción de etanol fueron eliminados desde 1995 hasta 2005. En esta situación hipotética, los individuos no sólo estaban dispuestos a cambiar su decisión de consumo, sino también a considerar modos alternativos de transporte, incluyendo el transporte público, en bicicleta o caminar. Como resultado, la cuota de mercado exterior alternativa aumentó un 4% y 6% y las cuotas del mercado de combustibles convencionales aumentó, mientras que el etanol combinado experimentó disminuciones en todos los distritos petroleros. Esta metodología también permite simular el impacto de esta eliminación en los precios de los combustibles. Los precios de los combustibles convencionales aumentaron en un rango entre 0,12 y 1,34 por ciento. Por último, ya que los diferentes tipos de compuestos oxigenados son combinados con la gasolina regular para el cumplimiento de las regulaciones de la EPA, la reducción de las cuotas de mercado de combustibles reformulados implica un trade-off de la demanda de estos productos oxigenados, cuya tasa de variación promedio es de 55,14% para la razón etanol- MTBE.

Quantitative studies have explored the work abilities of persons with specific vestibular-related symptoms, but there seems to be a dearth of research that has explored the work experience of persons-with- vestibular- disorders, so this qualitative study explored this phenomenon. Audio-recorded semi-structured interviews were conducted online. Thematic analysis was used to analyse the transcripts. Together, two researchers coded the transcripts and deductively identified the main themes on the main components of the expanded International Classification of Functioning, Disability, and Health scheme, and thereafter generated the sub-themes inductively. Fourteen people with various vestibular disorders and occupations in South Africa participated in the study. Participants reported having difficulty performing work-related tasks requiring attention to detail and ambulation, and work environmental conditions triggered their vestibular-related symptoms. Some participants received time off from work and support from their supervisors and colleagues, while others did not. Seeking mental services allowed them to overcome their negative feelings, medication suppressed their vestibular-related symptoms, and vestibular rehabilitation allowed them to focus on their work. Vestibular-related symptoms may hinder persons- with- vestibular- disorders from completing and participating in work-related activities, which may result in them experiencing negative feelings. The nature of some of the work-related tasks that they need to complete and experiencing negative feelings may trigger their vestibular-related symptoms. Together, the work-related activity limitations, participation restrictions, and environmental and personal factors may cause persons- with- vestibular- disorders to experience disability in their workplaces. To prevent this potential disability, persons with vestibular disorders should be supported by and receive workplace accommodations. Furthermore, they should be enrolled into work rehabilitation programmes that include, vestibular rehabilitation, medication regimens, and mental health services.

Extracellular vesicles (EVs) are nanosized structures containing proteins, lipids, and nucleic acids, released by living cells to the surrounding medium. EVs participate in diverse processes, such as intercellular communication, virulence, and disease. In pathogenic fungi, EVs carry enzymes that allow them to invade the host or undergo environmental adaptation successfully. InNeurospora crassa, a non-pathogenic filamentous fungus widely used as a model organism, the vesicle-dependent secretory mechanisms that lead to polarized growth are well studied. In contrast, biosynthesis of EVs in this fungus has been practically unexplored. In the present work, we analyzedN. crassaculture’s supernatant for the presence of EVs by dynamic light scattering (DLS), transmission electron microscopy (TEM) and proteomic analysis. We identified spherical membranous structures, with a predominant subpopulation averaging a hydrodynamic diameter (dh) of 68 nm and a particle diameter (dp) of 38 nm. EV samples stained with osmium tetroxide vapors were better resolved than those stained with uranyl acetate. Mass spectrometry analysis identified 252 proteins, including enzymes involved in carbohydrate metabolic processes, oxidative stress response, cell wall organization/remodeling, and circadian clock-regulated proteins. Some of these proteins have been previously reported in exosomes from human cells or in EVs of other fungi. In view of the results, it is suggested a putative role for EVs in cell wall biosynthesis and vegetative development inN. crassa.

La acción del capital y la minería en la región de Antofagasta desde fines del siglo XIX ha significado profundas transformaciones sociales y ambientales. Ese proceso de larga duración hoy encuentra continuidad y amplificación en la minería del litio en el Salar de Atacama. Desde la década de 1990, la dimensión étnica de la acción colectiva en ese territorio ha redefinido las relaciones interculturales posibilitando, en la segunda década de este siglo, la firma de convenios entre mineras y organizaciones atacameñas que involucran la transferencia directa de dinero como compensación a los impactos negativos que suponen sus operaciones, especialmente, en el balance hídrico del lugar. Este artículo caracteriza esta nueva etapa de la organización y movilización atacameña, a partir de las estrategias de negociación y gestión del territorio que están implementando las comunidades y que han hecho emerger fuertes cuestionamientos al interior y entre las organizaciones atacameñas trasladando el acostumbrado enfrentamiento entre empresas y comunidades al interior de las organizaciones indígenas.

Soil textural variability diminishes the effectiveness of conventional irrigation management. Variable rate irrigation (VRI) can address soil variability; however, users need guidance to prepare prescriptions for optimal water application. A study was conducted at Portageville, MO, USA, in 2016 and 2017 with the objective to compare yield and irrigation water use efficiency among three water-management treatments for cotton: rainfed, irrigated based on the USDA-ARS Irrigation Scheduling Supervisory Control And Data Acquisition (ISSCADA) system, and irrigated based on a water balance method. Sand content in the top 533 mm soil layer was estimated from apparent electrical conductivity (ECa). Yield values measured near an ECaobservation were averaged to create a data set containing sand content and associated yield. Although the trend was for the rainfed treatment to have the lowest yield in both years, the yield differences among all treatments were not significant when sand content was not considered. A strong effect of sand content on cotton yield was observed in both seasons, although the slopes differed among the water management treatments in 2016. The ISSCADA system tended to have a higher irrigation water use efficiency in both seasons, but the difference was not significant in 2016 when total irrigation applications were low. The study is continuing at Portageville and other locations and the ISSCADA system is constantly being improved to better meet the needs of agricultural producers.

HighlightsThe ARSPivot software facilitates variable-rate irrigation management of a center pivot irrigation system.The software embodies a system capable of generating site-specific prescription maps based on weather, plant, and soil water information.ARSPivot’s graphical user interface (GUI) incorporates easy-to-use geographic information system (GIS) tools that help its users to make irrigation management decisions.Abstract. The ARSPivot software was developed for the seamless operation of a complex network consisting of a variable-rate irrigation (VRI) center pivot system and an Irrigation Scheduling Supervisory Control and Data Acquisition (ISSCADA) system that interfaces with weather, plant, and soil water sensing systems. ARSPivot’s graphical user interface (GUI) incorporates a built-in geographic information system (GIS) that maps a center pivot system and facilitates the analysis of data relevant to its operation. The GIS was developed following a minimalistic approach with the objective of making its geospatial data analysis tools accessible to a wide range of users (farmers, irrigation consultants, and researchers). The post-harvest analyses of two experiments carried out in the Texas High Plains during the summers of 2016 and 2017 using a three-span VRI center pivot are presented to illustrate the advantages of using ARSPivot as a decision support tool and how its GIS tools help its users make better informed decisions regarding irrigation management. In these experiments, the north-northwest (NNW) portion of a field planted with corn (Zea mays L.) was irrigated using VRI zone control, and the south-southeast (SSE) portion was irrigated using VRI speed control. Experimental plots in the NNW portion were assigned one of three irrigation levels (80%, 50%, or 30% replenishment of soil water depletion to field capacity in the top 1.5 m), and their irrigation was scheduled using either a plant stress-based algorithm implemented in the ARSPivot software or manual weekly neutron probe (NP) readings. Plots in the SSE portion were assigned a single irrigation level of 80%, and their irrigation was scheduled using either the plant stress method or a two-step hybrid approach in which soil water sensing was combined with the plant stress method to determine irrigation depths. Soil water sensing data for the ISSCADA system were provided by NP readings during the 2016 season and by sets of time-domain reflectometers (TDRs) installed at depths of 15, 30, and 45 cm during the 2017 season. No significant differences were found during either season in terms of mean dry grain yield and crop water productivity (CWP) obtained from plots irrigated at the 80% level in both sides of the field, regardless of the irrigation scheduling method or the type of VRI application method used for irrigation. No significant differences were found during either season between mean dry grain yield and CWP of plots in the NNW portion irrigated using the plant stress-based method and NP readings at the 80% irrigation level. The lack of significant differences documented the potential of the ARSPivot system as a plant and soil water sensing-based decision support software for site-specific irrigation management of corn using a VRI center pivot system. Keywords: Center pivot irrigation, Decision support system, Geographic information system, Precision agriculture, Software.

Highlights.Precision agriculture (PA) applications in irrigation are stymied by lack of decision support systems.Modern PA relies on sensor systems and near real-time feedback for irrigation decision support and control.Sophisticated understanding of biophysics and biological systems now guides site-specific irrigation.The internet of things (IOT) enables new ways to increase yield per unit of water used and nutrient use efficiency. Keywords: Crop water productivity, Decision support system, Internet of things, Remote sensing, SCADA, Soil water content.

HighlightsMulti-faceted research efforts converged to an automated irrigation decision support system (DSS).Low-cost, solar-powered, wireless plant abiotic and biotic stress sensors were developed to aid the DSS.Low-cost, accurate TDR soil water sensors and a wireless node and gateway system were developed for the DSS.Sensor systems and research-based algorithms were integrated into an automated irrigation DSS and control system.Abstract. Variable-rate irrigation (VRI) is now possible with every new center pivot irrigation system sold, either using sector (speed) control or both sector and zone (radial along the pipeline) control. However, decision support systems able to generate a prescription for spatially varying irrigation based on crop water need have lagged far behind VRI equipment. Irrigation based on crop water need has been shown to increase both crop water productivity and nutrient use efficiency, meaning that an effective VRI decision support system (DSS) could improve profitability while conserving resources. In this article, we report separately on a VRI DSS using sensor-based plant and soil water feedback as implemented in four U.S. states. This article describes the genesis and development of the Irrigation Scheduling Supervisory Control and Data Acquisition (ISSCADA) system, of the integral plant and soil sensors, and of its wireless sensor network subsystems, as well as the role of multi-location research efforts and cooperative research and development agreements in the development of the needed plant and soil sensors and the ISSCADA and wireless sensor network systems. Keywords: Crop water productivity, Decision support system, Product development, Sensors, Variable-rate irrigation, VRI.

O Caulim e uma argila fundamentalmente composta pelo argilomineral caulinita, um silicato pertencente a familia dos filossilicatos. Esse mineral e uma importante materia-prima usada em grande numero de aplicacoes industriais, a principal delas na industria de papel. O beneficiamento de caulim na regiao do Serido do estado da Paraiba (PB) gera uma quantidade consideravel de rejeitos, cerca de 70% da materia-prima utilizada no processamento e descartada. O principal objetivo deste trabalho foi caracterizar o caulim da regiao do Serido da Paraiba a fim de adequar as etapas de beneficiamento. Quatro amostras de caulim foram caracterizadas pelas tecnicas de difracao de raios X e analise granulometrica a laser, sendo possivel conhecer sua composicao mineralogica, assim como determinar sua distribuicao granulometrica. As quatro amostras estudadas apresentaram a mesma composicao (caulinita, quartzo, feldspato e moscovita). Tendo em vista que a distribuicao granulometrica e homogenea e bastante fina, recomenda-se a substituicao de peneiras por hidrociclones no processo de beneficiamento aumentando assim a recuperacao massica, proporcionando a reducao dos custos de producao, permitindo um melhor aproveitamento do minerio e consequentemente reduzindo seus impactos ambientais. Porem para ter resultados mais representativos e necessaria uma caracterizacao tecnologica completa.

HighlightsPotatoes irrigated at 80% and 100% replenishment of soil water depletion to field capacity resulted in statistically similar tuber yields and irrigation water productivity.In the drier growing season, irrigation scheduling using sensor feedback resulted in fewer irrigations compared with the manual-control method.In the wetter growing season, irrigation scheduling using sensor feedback resulted in similar or better tuber yields compared with the manual-control method.Abstract. Few studies have investigated yield and crop water productivity of plant and soil water sensing feedback systems for site-specific irrigation management of a potato crop. In this two-year study (2018 and 2019), the irrigation scheduling supervisory control and data acquisition (ISSCADA) system developed by scientists at the USDA-ARS Conservation and Production Research Laboratory in Bushland, Texas, was used to manage a potato crop at three irrigation levels. The ISSCADA system used two different irrigation scheduling methods: (1) plant feedback and (2) a hybrid method that combines plant feedback with soil water sensing with a soil water depletion (SWD) threshold initially set at 50% and reduced to 35% in the second year. Tuber yield, crop water productivity (CWP), and irrigation water productivity (IWP) resulting from the two ISSCADA irrigation scheduling methods were compared with a manual-control method based on weekly neutron probe readings. The irrigation levels were 100%, 80%, and 60% (I100, I80, and I60) of full and were accomplished by either replenishment of SWD to field capacity or by the equivalent plant feedback or SWD thresholds of the ISSCADA system. In the second study year, the SWD threshold was reduced to 35%. Cumulative irrigation amounts for the ISSCADA treatment methods were significantly less compared with the manual-control method in the I100 levels for both years. This resulted in significantly smaller tuber yields and CWP in the first year of the study, a hot dry growing season. In the second year of the study, tuber yields and CWP were similar between irrigation scheduling methods, and IWP was significantly greater for the ISSCADA-plant feedback method. Considering the effect of irrigation treatment, the tuber yields, CWP, and IWP between the I100 and I80 levels were similar in both years, resulting in an average savings of 85 mm at the I80 level. Future studies are needed to investigate if the change in the SWD threshold could enable the ISSCADA-hybrid system to adjust to variable climatic conditions and successfully irrigate potatoes in this region. Keywords: Center pivot, Dynamic prescription maps, Plant feedback, Site-specific variable-rate irrigation, Soil water sensing feedback, Wireless sensor networks

Los criterios y estándares de calidad asociados al personal docente en el plano nacional han suministrado información relevante sobre las competencias, llevando a definir un conjunto de líneas de investigación prioritarias para los organismos reguladores, con foco en el aseguramiento de la calidad en educación superior. Una de las líneas prioritarias es el desarrollo y uso de indicadores de desempeño sobre la docencia de pregrado y posgrado, que centren su acción en la observación permanente e indagación de cada uno de los componentes que le configuran. Algunos datos estadísticos relativos a estudiantes, docentes, recursos, infraestructura y resultados del proceso académico se entrecruzan, buscando comprender la complejidad inherente y constitutiva de la docencia, sin embargo, la investigación en esta área de la mano de universidades u otros organismos, aún parece ser escasa. La presente nota busca reflexionar, brevemente, con base en los datos, sobre el fenómeno de la valoración del desempeño docente y su imperativo protagónico en la calidad educativa en educación superior.

This paper describes a differential algorithm for the protection of a three-phase transformer to differentiate transient phenomena, such as inrush currents and external faults from solid and turn-to-turn faults. This algorithm is based on the behavior of the second central moment (SCM) to identify the kind of event. Instantaneous differential currents are used as input signals to the algorithm once they are filtered and normalized. The algorithm compares the magnitude of the SCM with an established threshold based on the binomial distribution to achieve a successful identification of the event. If the magnitude of the SCM is above the limit, the algorithm identifies the event as a fault condition. Otherwise, the event is determined as a transient event or a steady-state condition. The threshold is setting-free if the transformer parameters are changed or if the harmonic content of the differential current varies. Also, the threshold does not have to be recalculated if the power system is modified. The D index was introduced to improve the fault-detection time when the current transformers experience saturation. This index uses the magnitude of the SCM as a basis and is compared with an established limit to detect the fault current. Both indices run in parallel, and if any of them does cross its respective threshold, a fault condition is determined. The algorithm is tested in a real-time digital simulator and is implemented in MATLAB. The algorithm was compared against the conventional differential protection with harmonic restraint to evaluate the performance of both indices in critical conditions. The results validate the performance of the algorithm and indicate that it can be the basis of a new algorithm to protect power transformers.

This study describes an extended approach to the differential protection of power transformers to identify turn-to-turn faults based on the second central moment (SCM). The proposal uses the differential currents as the input signals to the algorithm. Differential currents are filtered and normalised to allow the proposed algorithm to be independent of the transformer parameters (power, reactance, connection etc.). Then, the SCM magnitude of the differential currents is computed and compared with an established threshold to detect the internal faults. If the SCM magnitude exceeds the limit, an internal fault is detected. Otherwise, the event is determined as a transient event or steady state. The proposed algorithm was implemented in MATLAB and was tested on a three-phase system using a Real-Time Digital Simulator. For laboratory experiments, a real 55-kVA transformer setup was used to validate the effectiveness of the algorithm. The algorithm successfully identified turn-to-turn faults from steady state, as well as during transformer energisations, in over 1000 cases.

HighlightsStationary and moving infrared thermometers aboard a center pivot were compared.Comparisons were in terms of directional brightness temperature discrepancies.Discrepancies were within 1.8°C, and many were within 1.0°C.Larger discrepancies tended to occur for sparser vegetation cover.Abstract. Infrared thermometers (IRTs) can measure canopy temperature, which is useful for irrigation and crop management. Center pivot and lateral move irrigation systems are suitable platforms to transport IRTs across cropped fields at regular intervals. IRTs aboard center pivots, when used in conjunction with irrigation scheduling algorithms, have resulted in crop yield and crop water productivity that is equivalent to or greater than what can be achieved using soil water measurements of the root zone profile with a field-calibrated neutron probe. Irrigation scheduling algorithms perform best when stationary IRT measurements are supplemented with moving IRT arrays, where the former provides time series data and the latter provides spatially distributed data. However, the normal deflection of moving irrigation systems and other confounding factors have caused concern that moving IRT measurements may be degraded relative to stationary IRT measurements. Directional brightness temperatures (TB) measured by stationary and moving IRTs were compared over two corn and one potato season at the USDA Agricultural Research Service, Bushland, Texas. Moving and stationary TB were compared in terms of root mean square error, mean absolute error, and mean bias error, and were all < 1.8°C, and many were < 1.0°C, and r2 = 0.95. Error terms tended to be larger for potato, which had less vegetation cover compared with corn. However, error terms were similar to previous studies of calibration and spatial variability for IRTs and thermal imagers. Therefore, TB measurements of moving IRTs did not appear to be degraded relative to TB measurements of stationary IRTs for this study. However, interpretation of stationary and moving IRT measurements may be aided by addition of low cost imagers to distinguish vegetation from soil background. Keywords: Canopy temperature, Crop management, Evapotranspiration, Irrigation, Remote sensing, Sensors.

Corn ( L.) for grain continues to be an important crop for livestock feed in the Texas High Plains (THP) region despite lackluster prices. It offers greater crop water productivity compared with other crops grown in the region but also has a relatively high water requirement, which must be met by irrigation. The sole water resource in the region is the Ogallala Aquifer, which is declining because withdrawals exceed recharge, and this is of major concern. Producers are interested in the performance of drought-tolerant (DT) corn, but data on DT crop production functions are limited. From 2015 to 2017, studies of DT corn response to different irrigation treatments were conducted in the THP at Bushland, Texas. Results showed that grain yields, seasonal evapotranspiration (ETc), and crop water use efficiency (WUE) varied significantly between seasons and among different DT hybrids. Comparisons between a mid-season (MS) and an early-maturing (EM) hybrid showed: (1) at the severe deficit irrigation treatment level, grain yields were low, but the EM hybrid produced 400% more grain; (2) at the moderate deficit irrigation treatment level, grain yields and ETc were similar; and (3) at the full irrigation treatment level, the EM hybrid required 75 mm less water, but it produced 24% less grain. Non-hail damaged MS DT corn produced grain yields that were numerically greater than conventional corn grown in the THP in an optimal year. However, during drought seasons, DT hybrid response was not improved over conventional hybrids under severe deficit irrigation. This study demonstrated that MS DT corn hybrid P1151AM, irrigated at a level that fully met evapotranspiration demand, resulted in grain yield and WUE levels that were near the upper limits for corn produced in the THP. Further research is needed to determine the constancy of response among different DT hybrids under favorable and drought conditions. Keywords: Center pivot, Deficit irrigation, Early-maturing corn, Hail damage, Mid-season corn, Variable-rate irrigation, Water use efficiency.

Variable rate irrigation (VRI) sprinklers on mechanical move irrigation systems (center pivot or lateral move) have been commercially available since 2004. Although the number of VRI, zone or individual sprinkler, systems adopted to date is lower than expected there is a continued interest to harness this technology, especially when climate variability, regulatory nutrient management, water conservation policies, and declining water for agriculture compound the challenges involved for irrigated crop production. This article reviews the potential advantages and potential disadvantages of VRI technology for moving sprinklers, provides updated examples on such aspects, suggests a protocol for designing and implementing VRI technology and reports on the recent advancements. The advantages of VRI technology are demonstrated in the areas of agronomic improvement, greater economic returns, environmental protection and risk management, while the main drawbacks to VRI technology include the complexity to successfully implement the technology and the lack of evidence that it assures better performance in net profit or water savings. Although advances have been made in VRI technologies, its penetration into the market will continue to depend on tangible and perceived benefits by producers. Keywords: Center pivots, Crop water use efficiency, Irrigation, Management zones, Moving sprinkler irrigation systems, Precision irrigation, Sensor based systems.

RESUMENEn la presente investigación se planteó como objetivo general analizar jurídicamente los derechos constitucionales de los pueblos y comunidades indígenas del Ecuador. Desde el paradigma cuantitativo, se desarrolló con una metodología de tipo descriptiva documental con un diseño bibliográfico, permitiendo indagar en fuentes bibliográficas, articulando un cuerpo reflexivo teórico como contribución al fortalecimiento del basamento teórico-jurídico del derecho. La utilización de estos métodos hizo posible que se analice doctrina, cuerpos normativos, documentos jurídicos, entre otros. La encuesta es un método del nivel empírico que consiste en la recopilación de datos estadísticos, el cuestionario se aplicó a 96 pobladores de la zona de la comunidad Piñan, ubicada en la parroquia rural Imantag, Cantón Santa Ana de Cotacachi, provincia de Imbabura. Se concluye que, los derechos constitucionales de los pueblos y comunidades indígenas, en la actualidad son vulnerados en diferentes regiones y provincias del Ecuador, debido a la existencia de comunidades marginadas.

The growing installation of distributed energy resources (DER) in the network allows an active interaction between the transmission and distribution system operators. This interaction is possible mainly by the power electronic converters (PECs) incorporated in the DER, used as an interface with the network. The PECs, also known as smart inverters, offers excellent controllability features and allow DER to provide procurement services to the distribution and transmission network. This paper focuses on evaluating the reactive power control features of the smart inverter considering eight control local modes following the IEEE 1547-2018 standard. Moreover, it is proposed an optimal reactive power controller able to minimise the active power losses in the network by optimally adapting the reactive power injection/absorption of the smart inverter. This optimal controller ensures all the busbar voltages are inside the permissible limits, and the reactive power limits of the smart inverter are enforced. The Vestfold and Telemark distribution network model was implemented using DIgSILENT PowerFactory to evaluate the optimal and the eight local reactive power control modes. Simulation results show the proposed optimal reactive power control is the best option to offer the service of active power loss minimisation using smart inverters for the daily steady-state performance of the DSO network.

Advances in environmental and agricultural management are increasingly enabled by unattended data acquisition using internet‐of‐things (IOT) approaches. These approaches combine advanced sensors and wireless data transmission to automatically convey field data to the internet. Users, either human or machine, then can access and act upon the data from nearly anywhere in the world. Particularly in the case of machines automatically acting on the data, robustness, reliability and accuracy of data are crucial to preventing unintended outcomes of machine operations and continued supply of key services. Low‐cost, low‐power, and solar‐powered systems are important to enable market entry of advanced decision support systems based on IOT data acquisition approaches. The polar vortex outbreak of February 2021 in the central United States provided an extreme test of such a node and gateway system for automatic data acquisition and telemetry to the internet over the cellular telephone network. The system, codesigned by USDA‐ARS and Acclima, performed admirably despite air temperatures reaching a minimum of −24 °C, temperatures < 0 °C for 8 d and < −7 °C for 6 d, two snowstorms, and overcast conditions. The six nodes, gateway, and 36 sensors continued to function reliably with a data transmission failure rate of

The use of phasor measurement units (PMU) allows us to obtain synchronized measurements of various points in the network and whit them analyze the stability of power systems. This chapter presents an algorithm based on participation factors to estimate generator clustering and to evaluate its application on controlled islanding on a power system, with distributed generation, using the data from PMUs after a severe disturbance. The proposed islanding detection method uses the data obtained from PMUs to represent the dynamics of the entire power system and form a measurement matrix, updated using a sliding window, containing the angles of the voltage phasors. Then, a covariance matrix is computed, and the eigenvalues and eigenvectors of this matrix are obtained. Subsequently, the most energetic eigenvalue is identified, and its participation factors are calculated. The participation factors are used as a contribution measurement of each generator into the most energetic eigenvalue, i.e., they will show the contribution made by each one after a disturbance. The clusters will be formed by generators sharing the same participation level. Controlled islanding condition of the system will be evaluated by using the clustering schemes proposed in the literature.

There are different definitions for Smart Grid, one of them is: Smart Grids is that it employs a wide variety of distributed energy resources (DER). In such conditions, the increasing local generation requires a new type of approach for protection. Ensuring the function of a relay to satisfy the requirements of the development of the smart grid and perform the protection task with high reliability, involves solving different technical aspects. In order to remove the fault with a minimum area of interruption, it requires the setup of multiple protection relays and their technical coordination. In order to meet the above requirements, protection devices based on various hardware platforms, different techniques and the on-site operational management of these devices have been proposed. An interesting feature proposed for the Smart Grid is self-healing. This means that the system is capable of continuing the power supply after any kind of disturbances. Self-healing is, in fact, a broad concept including the stability of transmission grids, but here the focus is on the protection of MV distribution networks. In this context, one way to achieve the self-healing functionality is to switch over to island operation in case of a fault in some parts of the network. The successful use of the local generation for achieving controlled island operation in some fault cases requires the use of suitable telecommunication between different parts of the system. In addition to this, there is a need to adapt the protection configuration to the system state. Especially critical in this respect is the power generated by the local sources and the loading in various parts of the network. Depending on the load/generation balances the size of suitable islands to be used in fault cases may be different at different times.

This paper presents a descriptive statistical analysis (DSA) of time-series of electro-mechanical quantities related to the frequency control (e.g. kinetic energy (KE), electrical frequency and power demand) of the Nordic power system (NPS). The idea of the DSA is to identify main observables features and patterns between these variables. Historical data publicly available has been used in this research paper; pre-processing included evaluating and identify missing data, and it filled by using the linear interpolation. The DSA uses descriptive statistical indicators to obtaining observable features. The dispersion analysis is used to observes how affects the KE to the electrical frequency. The data is grouped by weeks, days and hours, and its correlation coefficient was calculated. A correlation analysis between the KE and the power demand was computed, and the linear regression was used to construct a prediction model.

This research investigates the positive changes in the system frequency response indicators caused by the implementation of a set of optimal settings of an under-frequency load shedding (UFLS) scheme. The optimal under-frequency load shedding (UFLS) scheme is optimised by minimising the total amount of load shedding and taking into account the recovery process of the system frequency into its operational values after several losses of generation and satisfies the requirements of the under-frequency load shedding standard (PRC-006-SERC-02). The idea of implementing the optimal UFLS scheme is to identify how changes the minimum frequency, minimum time, rate of change of frequency and steady-state frequency when the amount of load shedding change. The optimal UFLS scheme formulation starts with identifying the variables to control with the optimisation and its respective bounds. Then, the objective function is formulated in terms of the total load shedding, and finally, the restrictions and requirements of the systems are written as inequality constraints. The optimal UFLS is evaluated in the IEEE 39-bus system. The simulations results demonstrate the suitability of the optimal UFLS to improve the frequency response indicators.

Lithium mining in Chile’s Salar de Atacama (SdA) has a relatively long and controversial history, especially when it comes to the local Indigenous peoples. In this context, this paper looks at the ways mining activities, and different visions of territory and indigeneity co-produce each other in the particular context of the SdA. For this, we use historical and ethnographic methods and draw on studies in anthropology and geography. We aim to escape simplistic images of Indigenous peoples’ reactions to mining as reflecting victimhood, resistance, or strategic pragmatism, and show instead how individuals and groups organize and express themselves in ambivalent ways, maintaining complex relationships with both mining and the territory. According to our local interlocutors, struggles around territory in the SdA mainly concern water scarcity, the survival of this unique ecosystem’s biological diversity, as well as continuity and change in local lifeways. While recent agreements between mining companies and local communities may benefit some individuals, they are also generating inter- and intra- community tensions over these issues. We find that mining shapes what ’indigenous’ means and who can claim this identity, while Indigenous mobilization in turn shapes how mining is perceived and carried out. Together, mining and Indigenous mobilization produce a particular kind of territory, pervaded by diverse lines of both consensus and tension. Rather than contradictions, the ambivalent positions Indigenous peoples maintain become comprehensible when considering, ethnographically and historically, the particular places and life- worlds they inhabit, and the asymmetrical patterns of constraint and opportunity they face. More broadly, the paper raises questions about the implications of a global transition to renewable energy based on lithium battery technologies, and ethical responses to the climate crisis.

This study describes a new differential protection algorithm for power transformers, which is not affected by transient conditions. The proposed algorithm uses the statistical second central moment, statistical variance, to characterise the signal waveform. The goal is to obtain the variance from each differential current after a pre-processing filter stage and to compare it with a threshold. The event will be identified as an internal fault, or otherwise as an inrush current. The algorithm was implemented in MATLAB, and a broad array of cases was carried out using the electromagnetic transient software PSCAD. All results show the algorithm successfully differentiated inrush from the internal fault conditions in over 2000 cases.

The accurate prediction of solute transport in water distribution systems has become a critical component of efforts aimed at delivering clean drinking water safely to large urban populations. One of the central assumptions that water quality models have traditionally relied upon dictates that, in a four-way junction, two incoming flows of differing quality will mix perfectly to produce two outgoing flows of equal quality, and that such complete mixing occurs irrespective of the specific assemblage characteristics of any particular four-way junction. In this study, laboratory experiments were conducted in order to characterize solute mixing patterns at double-tee and wye junctions, both of which are commonly found in urban water distribution systems. Results show that mixing at double-tee junctions tends to be less than complete when the tee connectors are located adjacent to each other and mix to a greater degree than flows at cross junctions.

Different thermal-based plant feedback systems have been used for irrigation management of cotton and grain crops in the Texas High Plains region, producing yields that are similar or better than irrigation scheduling using the neutron probe. However, there are limited studies using plant feedback systems to actively scheduling irrigations for corn. In this 2-year study, a drought tolerant and a conventional hybrid were managed under a variable rate center pivot irrigation system. The main treatments were manual and plant feedback irrigation scheduling based on weekly neutron probe readings and an integrated crop water stress index (CWSI), respectively. In each main treatment, three irrigation treatment levels were established. Crop responses were compared between irrigation methods and levels. Results demonstrated that overall grain and biomass yields and grain WUE for the plant feedback-control plots were similar to those from the manual-control plots for both years. These results indicate that a plant feedback system using a CWSI could be used to manage corn in a semi-arid region and over a large-sized field. The plant feedback system could provide convenience and time savings to farmers who manage multiple center pivot fields.

The Ecuadorian Government has, since the end of 2011, promoted an initiative for using pure jatropha oil, derived from the seeds of Jatropha curcas L., to generate electricity to supply Floreana Island (one of the Galapagos Islands). In the present study, nine elite accessions of J. curcas from tropical dry forests in Ecuador were cultivated for the purpose of evaluating seed production in relation to the propagation method used (seed, cutting). A split-plot design with three replicates was applied. Seed production, measured over a period of 7 years (2009–2015) showed a large year-to-year variation. However, seed production varied significantly among accessions and depended on the propagation method (seeds or cuttings). Propagation by stem cuttings stabilized the variability in the vegetative and seed production components measured, increasing the strength of their relationships with seed yield. The three highest yielding accessions produced 0.28–0.30 kg of seeds tree−1 year−1. As seed yield was not correlated with annual precipitation, the year-to-year variation in production of accessions indicates the effect of other factors not considered here, such as agronomic practices. The study findings suggest that agroforestry practices could be developed that would enable J. curcas to play a predominant role in a strategy for tropical dry forests aimed at reducing poverty (also known as pro-poor growth strategy).

The Altai-Uliastai regional power system (AURPS) is a regional power system radially interconnected to the power system of Mongolia. The 110 kV interconnection is exceptionally long and susceptible to frequent trips because of weather conditions. The load-rich and low-inertia AURPS must be islanded during interconnection outages, and the under-frequency load shedding (UFLS) scheme must act to ensure secure operation. Traditional UFLS over-sheds local demand, negatively affecting the local population, especially during the cold Mongolian winter season. This research paper proposes a novel methodology to optimally calculate the settings of the UFLS scheme, where each parameter of the scheme is individually adjusted to minimise the total amount of disconnected load. This paper presents a computationally efficient methodology that is illustrated in a specially created co-simulation environment (DIgSILENT&reg, PowerFactoryTM + Python). The results demonstrate an outstanding performance of the proposed approach when compared with the traditional one.

Automated irrigation scheduling of grain crops using a combination of plant and soil water sensing feedback has not been widely investigated. A three-year study was conducted at Bushland, Texas to investigate irrigation management of grain sorghum (Sorghum bicolor, L.), in 2012 using plant feedback with a single thermal stress threshold, and in 2018 and 2019 using multiple thermal stress thresholds and a combination of plant and soil water sensing (Hybrid) feedback. The goals of the studies were to optimize grain yield, crop water productivity (CWP) and irrigation water productivity (IWP) using sensor feedback at irrigation levels similar to 80 %, 50 % and 30 % (designated I80, I50 and I30) replenishment of soil water depletion to field capacity as determined with weekly neutron probe readings (the “manual” method). Results in 2012 indicated that irrigation scheduling using plant feedback alone with a single thermal stress threshold produced grain yields that were significantly less (0.49 and 0.38 kg m−2) compared with the manual method (0.63 and 0.51 kg m−2) at the I80 and I50 treatment levels, respectively. However, in 2018, the Hybrid feedback method produced mean grain yields (0.87 kg m−2) that were significantly greater compared with the plant feedback (0.76 kg m−2) and manual (0.74 kg m−2) irrigation scheduling methods at the I80 treatment level. In 2019, mean grain yields (0.86, 0.83 and 0.88 kg m−2), CWP (1.25, 1.29 and 1.20 kg m-3) and IWP (2.11, 2.19 and 1.88 kg m-3) for the Hybrid, plant feedback and manual methods, respectively, were similar at the I80 level. These results suggest that plant and soil water sensing feedback using multiple thermal stress thresholds and watering levels have the potential to produce optimal crop response for grain sorghum. More research is required to test the efficacy of soil water sensing in combination with plant sensing for other crops.

Power shunt reactors are critical elements in electric power systems for controlling reactive power and maintaining voltage within a permissible range in transmission systems. Protection schemes for shunt reactors are similar to those used in power transformers, e.g., the differential, overcurrent, and distance protection schemes. However, these protection schemes may misoperate for several reasons such as a decaying DC component when the reactor is energized, or the occurrence of current transformer saturation when an external fault occurs. In this context, a novel differential protection algorithm for power shunt reactors is proposed. This algorithm uses the magnitude of the second central moment as a basis for identifying whether the event corresponds to an internal fault. The proposed algorithm was tested and implemented using PSCAD and the MATLAB software. Current transformer saturation and noise were considered in all the events evaluated. The results show that the proposed algorithm accurately discriminates between internal and external faults as well as transient events such as inrush currents. Furthermore, the algorithm exhibits a limited capability for detecting turn-to-turn faults until 2% of short-circuited turns.

This study aims to create a cost function for residential subdivisions based on three key variables: population density, area, and slope. The cost function was developed by minimizing the capital cost of representative residential water distribution networks through a genetic algorithm and a heuristic search method known as the greedy algorithm. To test the proposed cost function and determine if a more efficient design would reduce cost, two subdivisions in Tucson, Arizona, were compared to an equivalent theoretical oblong network. The greedy algorithm required a fraction of the time demanded by the genetic algorithm and arrived at subdivision network costs that were consistently equal to or lower than the best solutions found by the genetic algorithm. Both optimization methods obtained results indicating that area has the greatest effect on cost and that the effect of population density is negligible when dealing with small areas.

This work presents a postoptimization methodology for refining the solutions found by adaptive search algorithms used in the design of large water distribution networks. The approach uses two heuristics to search for an optimal combination of pipes that, after a reduction of their diameters, will maximize cost savings while continuing to meet design constraints. Adaptive search methods are often used to design urban water distribution networks when the number of pipes in the network is insignificant. For complex, real-world networks, however, such methods are computationally demanding, and they have difficulty finding near-global optima. To identify a solution as close to the global optimum (and in which no pipe can be reduced without violating pressure constraint), requires a high-speed computer potentially running for a long time and also probably some good fortune. The postoptimization approach presented in this paper is shown to be an efficient complement to heuristic search algorithms used in...