A Multi-Level Operation Method for Improving the Resilience of Power Systems under Extreme Weather through Preventive Control and a Virtual Oscillator.

This paper proposes a multi-level operation method designed to enhance the resilience of power systems under extreme weather conditions by utilizing preventive control and virtual oscillator (VO) technology. Firstly, a novel model for predicting time intervals between successive failures of the power system during extreme weather is introduced. Based on this, this paper proposes a preventive control method considering the system ramping and transmission constraints prior to failures so as to ensure the normal electricity demand within the system. Further, a VO-based adaptive frequency control strategy is designed to accelerate the regulation speed and eliminate the frequency deviation. Finally, the control performance is comprehensively compared under different experimental conditions. The results verify that the method accurately predicted the time of the line fault occurrence, with a maximum error not exceeding 3 min compared to the actual occurrence; also, the virtual oscillator control (VOC) strategy outperformed traditional droop control in frequency stabilization, achieving stability within 2 s compared to the droop control's continued fluctuations beyond 20 s. These results highlight VOC's superior effectiveness in frequency stability and control in power systems.

Guidance on validation of lethal control measures for foodborne pathogens in foods.

Food manufacturers are required to obtain scientific and technical evidence that a control measure or combination of control measures is capable of reducing a significant hazard to an acceptable level that does not pose a public health risk under normal conditions of distribution and storage. A validation study provides evidence that a control measure is capable of controlling the identified hazard under a worst-case scenario for process and product parameters tested. It also defines the critical parameters that must be controlled, monitored, and verified during processing. This review document is intended as guidance for the food industry to support appropriate validation studies, and aims to limit methodological discrepancies in validation studies that can occur among food safety professionals, consultants, and third-party laboratories. The document describes product and process factors that are essential when designing a validation study, and gives selection criteria for identifying an appropriate target pathogen or surrogate organism for a food product and process validation. Guidance is provided for approaches to evaluate available microbiological data for the target pathogen or surrogate organism in the product type of interest that can serve as part of the weight of evidence to support a validation study. The document intends to help food manufacturers, processors, and food safety professionals to better understand, plan, and perform validation studies by offering an overview of the choices and key technical elements of a validation plan, the necessary preparations including assembling the validation team and establishing prerequisite programs, and the elements of a validation report.

Efficacy of essential oils in the management of soft rot caused by Pectobacterium aroidearum in lettuce

Lettuce is susceptible to several diseases, especially soft rot caused by bacteria of the genus Pectobacterium. Due to the adaptability of this pathogen and the lack of disease control registered for the crop, the objective of this work was to evaluate the effects of essential oils in the management of soft rot caused by P. aroidearum in lettuce. The study was developed at the Universidade do Estado da Bahia, Juazeiro, BA, Brazil, and the essential oils (EOs) of orange, bergamot, lemongrass, palmarosa, citronella, cloves, tea tree, rosemary, sage, and ginger were used in concentrations of 0.25; 0.5; 0.75 and 1.0% to assess the in vitro growth inhibition of the bacterium. Subsequently, the curative effects of the disease were evaluated by applying the EOs that obtained the best results in vitro in lettuce plants of the susceptible variety "Mônica". The treatments were applied, via spraying, 12 hours after inoculation using the bite method with bacterial suspension. The best in vivo treatment was selected to assess its preventive and curative activity, as well as to find the ideal concentration for reducing epidemiological variables and chromatographic characterization. The EOs of palmarosa, sage, citronella, lemongrass, and cloves (0.25%), and that of sage (0.75%), inhibited bacterial growth in vitro. The EO of salvia showed the best results in vivo, inhibiting the growth of the disease in concentrations of 0.50 and 0.75%, so it was selected for the preventive and curative control tests alone. The preventive treatment was not efficient for the management of soft rot in lettuce, however, from the regression analysis, a concentration of 0.64% of the salvia EO was found as a potential for curative control of this bacteriosis, as it reduces the incidence and severity of the disease. Linalyl acetate and linalool were found in higher concentrations in the chromatographic analysis. These components, probably, conferred the bactericidal capacity of the EO of sage, being potential for the use in the control of P. aroidearum in lettuce.

El ciclo evolutivo de parásitos de la familia anisakidae. Hacia una prospectiva de medidas sanitarias de control / The evolutionary cycle of parasites of the anisakidae family. towards a prospective of sanitary control measures

Las larvas de nematodos en los peces, generalmente corresponde a especies de la familia Anisakidae, son gusanos redondos, sin segmentación; con hospedadores intermediarios y definitivos y un huésped accidental que es el humano, en quién va producir una enfermedad parasitaria del tacto digestivo, mundialmente conocida como anisakiasis, asociada a reacciones de hipersensibilidad debido a los alérgenos del parásito. La presencia de estos parásitos en los productos de la pesca, deberá ser controlada con medidas preventivas establecidas en la legislación sanitaria de países; estableciendo profilaxis, medidas higiénicas como consumir el pescado cocido, o sometido previamente a congelación a -20°C por 48 a 72 horas, para prevenir la enfermedad. Cuando enfocamos hacia una prospectiva de medidas sanitarias de control preventivo, se plantea el establecimiento de un plan de requerimientos de alimentos seguros, basado en el análisis de riesgos y control de puntos críticos (HACCP), constituido por un paquete de documentos escritos basados en los principios de seguridad de alimentos; que contendrá: el análisis de riesgos; controles preventivos; programas en la cadena de suministros; delineamiento de los procedimientos para ser seguidos por monitoreo, acciones correctivas y verificación. Estará basado en las obligaciones que se puedan establecer bajo jurisdicción regulatoria para el pescado, en cuanto a la pesca o captura, manipulación a bordo o en la orilla y mecanismos de conservación hasta el expendio; que dé lugar a un manual de buenas prácticas de manufactura, análisis de riesgo y controles preventivos de riesgos para la regulación de alimentos de origen marino para consumo humano

The larvae of nematodes in fish generally correspond to species of the Anisakidae family, they are round worms, without segmentation; with intermediate and definitive hosts and an accidental host that is human, in whom it will produce a parasitic disease of the digestive tract, worldwide known as anisakiasis, associated with hypersensitivity reactions due to parasite allergens. The presence of these Parasites in fishery products should be controlled with preventive measures established in the sanitary legislation of countries; establishing prophylaxis, hygienic measures such as consuming the cooked fish, or previously subjected to freezing at -20 ° C for 48 to 72 hours to prevent the disease. When we focus on a prospective of preventive control sanitary measures, the establishment of a plan for safe food requirements based on risk analysis and control of critical points (HACCP), constituted by a package of written documents based on the principles, is considered food safety; which will contain: risk analysis; preventive controls; programs in the supply chain; delineation of the procedures to be followed by monitoring, corrective actions and verification. It will be based on the obligations that can be established under the regulatory jurisdiction for fish, in terms of fishing or capture, handling on board or on the shore and conservation mechanisms up to the sale; that results in a manual of good manufacturing practices, risk analysis and preventive risk controls for the regulation of food of marine origin for human consumption

Identification of generator criticality and transient instability by supervising real-time rotor angle trajectories employing RBFNN.

Identification of transient stability state in real-time and maintaining stability through preventive control technology are challenging tasks for a large power system while integrating deregulation constraints. Widely employment of the phasor measurement units (PMUs) in a power system and development of wide area management systems (WAMS) give relaxation to monitoring, measurement and control hurdles. This paper focuses on two research objectives; the first is transient stability assessment (TSA) and second is selection of the appropriate member for the control operation in unstable operating scenario. A model based on the artificial machine learning and PMU data is constructed for achieving both the objectives. This model works through prompt TSA status with radial basis function neural network (RBFNN) and validates it with PMU data to determine the criticality level of the generators. To reduce the complexity of the model a transient stability index (TSI) is proposed in this paper. A RBFNN is used to determine the transient stability aspects like stability status of system, coherent group and criticality rank of generator and preventive control action, following a large perturbation. PMUs measure post-fault rotor angle values and these are used as input for training RBFNN. The proposed approach is demonstrated on the IEEE 10-generator 39-bus, 16-generator 68-bus and 50-generator 145-bus test power systems successfully and the effectiveness of the approaches is discussed.

Improving preventive locust management: insights from a multi-agent model.

BACKGROUND: Preventive management of locust plagues works in some cases but still fails frequently. The role of funding institution awareness was suggested as a potential facilitating factor for cyclic locust plagues. We designed a multi-agent system to represent the events of locust plague development and a management system with three levels: funding institution, national control unit and field teams. A sensitivity analysis identified the limits and improvements of the management system. RESULTS: The model generated cyclic locust plagues through a decrease in funding institution awareness. The funding institution could improve its impact by increasing its support by just a few percent. The control unit should avoid hiring too many field teams when plagues bring in money, in order to ensure that surveys can be maintained in times of recession. The more information the teams can acquire about the natural system, the more efficient they will be. CONCLUSION: We argue that anti-locust management should be considered as a complex adaptive system. This not only would allow managers to prove to funders the random aspect of their needs, but would also enable funders and decision-makers to understand and integrate their own decisions into the locust dynamics that still regularly affect human populations. © 2017 Society of Chemical Industry.

Essential Oil of Cymbopogon citratus on the Control of the Curvularia Leaf Spot Disease on Maize.

The Curvularia Leaf Spot is becoming more common due to the culture expansion and the low resistance of the cultivated genotypes in tropical regions. Thus, the objective was to evaluate the fungitoxicity of the essential oil of Cymbopogon citratus upon the phytopathogen Curvularia lunata, causative agent of the Curvularia Leaf Spot. There was realized pathogenicity tests of C. lunata in maize plants, phytotoxicity of the essential oil of C. citratus and gas chromatography attached, germination tests of the conidia, and of in vitro inhibition of C. lunata. Also, there were realized tests aiming at verifying the phytopathogen control in vivo. In the pathogenicity tests, there were verified symptoms of the disease in all of the suspensions tested on plants. It was observed that the essential oil concentrations of 7.5 µL mL-1 to 50 µL mL-1 were phytotoxic. The majoritarian chemical components of the essential oil of C. citratus were Geranial (41.46%) and Neral (32.43%). The concentrations of 5 and 7.5 µL mL-1 inhibited 100% of conidia germination. None of the concentrations evaluated effectively inhibited C. lunata mycelial growth in in vitro tests. In the preventive control, the concentration of 7.5 µL mL-1 was sufficient for the reduction of the progress of the disease, however the curative control was not efficient on the tested dosages.

Model of epidemic control based on quarantine and message delivery.

The model provides two novel strategies for the preventive control of epidemic diseases. One approach is related to the different isolating rates in latent period and invasion period. Experiments show that the increasing of isolating rates in invasion period, as long as over 0.5, contributes little to the preventing of epidemic; the improvement of isolation rate in latent period is key to control the disease spreading. Another is a specific mechanism of message delivering and forwarding. Information quality and information accumulating process are also considered there. Macroscopically, diseases are easy to control as long as the immune messages reach a certain quality. Individually, the accumulating messages bring people with certain immunity to the disease. Also, the model is performed on the classic complex networks like scale-free network and small-world network, and location-based social networks. Results show that the proposed measures demonstrate superior performance and significantly reduce the negative impact of epidemic disease.