A potential use for the C-band polarimetric SAR parameters to characterise the soil surface over bare agriculture fields

The objective of this study was to analyze the potential of the C-band polarimetric SAR parameters for the soil surface characterization of bare agricultural soils. RADARSAT-2 data and simulations using the Integral Equation Model (IEM) were analyzed to evaluate the polarimetric SAR parameters' sensitivities to the soil moisture and surface roughness. The results showed that the polarimetric parameters in the C-band were not very relevant to the characterization of the soil surface over bare agricultural areas. Low dynamics were often observed between the polarimetric parameters and both the soil moisture content and the soil surface roughness. These low dynamics do not allow for the accurate estimation of the soil parameters, but they could augment the standard inversion approaches to improve the estimation of these soil parameters. The polarimetric parameter alpha_1 could be used to detect very moist soils (>30%), while the anisotropy could be used to separate the smooth soils

Soil surface moisture estimation over a semi-arid region using ENVISAT ASAR radar data for soil evaporation evaluation

The present paper proposes a method for the evaluation of soil evaporation, using soil moisture estimations based on radar satellite measurements. We present firstly an approach for the estimation and monitoring of soil moisture in a semi-arid region in North Africa, using ENVISAT ASAR images, over two types of vegetation covers. The first mapping process is dedicated solely to the monitoring of moisture variability related to rainfall events, over areas in the "non-irrigated olive tree" class of land use. The developed approach is based on a simple linear relationship between soil moisture and the backscattered radar signal normalised at a reference incidence angle. The second process is proposed over wheat fields, using an analysis of moisture variability due to both rainfall and irrigation. A semi-empirical model, based on the water-cloud model for vegetation correction, is used to retrieve soil moisture from the radar signal. Moisture mapping is carried out over wheat fields, showing high variability between irrigated and non-irrigated wheat covers. This analysis is based on a large database, including both ENVISAT ASAR and simultaneously acquired ground-truth measurements (moisture, vegetation, roughness), during the 2008–2009 vegetation cycle. Finally, a semi-empirical approach is proposed in order to relate surface moisture to the difference between soil evaporation and the climate demand, as defined by the potential evaporation. Mapping of the soil evaporation is proposed

Nonlinear Speed Control of Switched Reluctance Motor Drives Taking into Account Mutual Inductance

A speed control algorithm is proposed for variable speed switched reluctance motor (SRM) drives taking into account the effects of mutual inductances. The control scheme adopts two-phase excitation; exciting two adjacent phases can overcome the problems associated with single-phase excitation such as large torque ripple, increased acoustic noise, and rotor shaft fatigues. The effects of mutual coupling between two adjacent phases and their contribution to the generated electromagnetic torque are considered in the design of the proposed control scheme for the motor. The proposed controller guarantees the convergence of the currents and the rotor speed of the motor to their desired values. Simulation results are given to illustrate the developed theory; the simulation studies show that the proposed controller works well. Moreover, the simulation results indicate that the proposed controller is robust to changes in the parameters of the motor and to changes in the load torque

Les goitres plongeants : particularites cliniques, radiologiques et therapeutiques

Introduction: Les goitres plongeants, devenus rares de nos jours, posent des problèmes diagnostiques et chirurgicaux particuliers. Leur prise en charge est facilitée par l’apport de la tomodensitometrie permettant de planifier l’attitude thérapeutique.Le but de ce travail est de préciser les modalités d’exploration et de prise en charge chirurgicale des goitres plongeants.Matériels et méthodes : Nous rapportons une étude rétrospective portant sur42 cas de goitre plongeant colligés sur une période de 11 ans entre 2001 et 2011.Résultats : L’âge moyen de nos patients était de 56,9 ans (36-86 ans). Le sex-ratio était de 0,13. La tuméfaction basi-cervicale était le motif de consultation le plus fréquent, rapportée dans 74 % des cas associée à des signes de compression oesotrachéale dans 45% des cas.Une paralysie récurrentielle unilatérale a été objectivée dans 3 cas.Une radiographie de thorax a montré un élargissement médiastinal dans 23% des cas avec déviation trachéale chez63 % des malades. Une TDM cervico-thoracique pratiquée dans 85% des cas a confirmé le diagnostic. Le traitement chirurgical était mené par voie cervicale exclusive chez tous les patients. Une paralysie récurentielle a été observée dans 3 cas. Aucune hypoparathyroïdie définitive n’a été rapportée avec un reculmoyen de 24mois.Conclusion : Les goitres plongeants devenus rares du fait de la prise en charge plus précoce des nodules thyroïdiens. Ils posent actuellement moins de difficultés thérapeutiques. L’indication chirurgicale est toujours formelle devant le risque vital qu’ils posent.Mots clés : goitre cervicothoracique, thyroïdectomie, paralysie récurrentielle, hypoparathyroïdie.Introduction: Substernal goiters, becoming rare, present diagnositic and therapeutic problems.Their management is facilitated by the contribution of computed tomography for planning the therapeutic approach. The aim of this study is to specify the procedures for exploration and surgical management of substernal goiters.Materials and Methods: We report a retrospective study of 42 cases of substernalgoiters collaged over a period of 11 years between 2001 and 2011.Results: The mean age was 56,9 years (36- 86 years). The sex ratio was 0,13. Cervical swelling was the most common reason for consultation, reported in 74% of cases associated with signs of oesotrachealcompression in 45% of cases. Unilateral laryngeal palsy has been objectified in 3 cases. Chest-x-Ray showed widening of mediastinal shadowwith tracheal deviation in 63% of patients. A cervico-thoracic CT performed in 85% of cases confirmed the diagnosis of substernal goiters. The cervical approach has been used in all cases. Laryngeal nerve palsy was observed in 3 cases. No definitive hypoparathyroidism have been reported with a mean of 24 months.Conclusion: Substernal goiters become rare due to the earlier diagnosis of thyroid nodules. They currently present fewer therapeutic difficulties, and must be managed surgically because of vital risk.Key words: substernal goiter, thyroidectomy, laryngeal nerve palsy, hypoparathoidism

The International Pharmacopoeia: Focus, Processes, Response to COVID-19 and Collaboration with other Pharmacopoeias

The World Health Organisation develops and promotes international standards for pharmaceutical products, in support of efforts to increase access to quality-assured medicines for all, and to safeguard patients from substandard and falsified medicines. The International Pharmacopoeia is a key output of this work. Its focus, processes to establish texts for inclusion or revision, response to COVID-19 and the collaboration with other Pharmacopoeias shall be discussed in this review. Pharmacopoeias provide public standards (written norms as well as physical reference standards), which ensure the quality of medicines by defining the attributes that are essential to their safety and efficacy. They consist of analytical methods to test for the identity, purity and content of pharmaceutical products, together with acceptance criteria to evaluate test results, and information about storage, labelling and production. Pharmacopoeias greatly facilitate the development of multi-source medicines (generics) by defining minimum quality standards that a group of medicines must meet in order to be considered of commensurate safety, quality and effectiveness as the originator product(s). The added value of The International Pharmacopoeia lies in its focus on monographs of particular relevance to lowand middle-income countries which may not have sufficient resources to develop national pharmacopoeias. In a globalised world, where medicines and health products are frequently sourced from several countries with differing regulatory standards and requirements, and when the response to Public Health Emergencies of International Concern, like the COVID-19 pandemic, necessitates swift and equitable access to urgently needed quality-assured therapeutics, such a resource is indispensable

Международная фармакопея: основные направления деятельности, организация работы, борьба с COVID-19 и сотрудничество с другими фармакопеями

The World Health Organisation develops and promotes international standards for pharmaceutical products, in support of efforts to increase access to quality-assured medicines for all, and to safeguard patients from substandard and falsified medicines. The International Pharmacopoeia is a key output of this work. Its focus, processes to establish texts for inclusion or revision, response to COVID-19 and the collaboration with other Pharmacopoeias shall be discussed in this review. Pharmacopoeias provide public standards (written norms as well as physical reference standards), which ensure the quality of medicines by defining the attributes that are essential to their safety and efficacy. They consist of analytical methods to test for the identity, purity and content of pharmaceutical products, together with acceptance criteria to evaluate test results, and information about storage, labelling and production. Pharmacopoeias greatly facilitate the development of multi-source medicines (generics) by defining minimum quality standards that a group of medicines must meet in order to be considered of commensurate safety, quality and effectiveness as the originator product(s). The added value of The International Pharmacopoeia lies in its focus on monographs of particular relevance to low- and middle-income countries which may not have sufficient resources to develop national pharmacopoeias. In a globalised world, where medicines and health products are frequently sourced from several countries with differing regulatory standards and requirements, and when the response to Public Health Emergencies of International Concern, like the COVID-19 pandemic, necessitates swift and equitable access to urgently needed quality-assured therapeutics, such a resource is indispensable.Всемирная организация здравоохранения (ВОЗ) занимается разработкой и распространением международных стандартов для лекарственных средств, чтобы обеспечить всеобщий доступ к гарантированно качественным препаратам и оградить пациентов от недоброкачественных и фальсифицированных лекарственных средств. Международная фармакопея — один из важнейших результатов работы ВОЗ в этой области. В статье рассмотрены основные направления деятельности Международной фармакопеи, порядок подбора текстов для включения в издание или их пересмотра, участие в борьбе с COVID-19 и сотрудничество с другими фармакопеями. Фармакопеи предлагают общедоступные стандарты (в виде текстов с требованиями и стандартных образцов), позволяющие обеспечить качество лекарственных средств за счет нормирования показателей, наиболее важных для безопасности и эффективности. Фармакопейные стандарты представлены методами анализа подлинности, чистоты и состава лекарственных средств, критериями приемлемости получаемых результатов, а также информацией о хранении, маркировке и производстве лекарственных средств. Наличие фармакопейных монографий существенно упрощает разработку воспроизведенных лекарственных средств согласно заданным минимальным стандартам качества, которым должен соответствовать препарат, чтобы можно было считать его сопоставимым с оригинальным препаратом (или несколькими) по безопасности, качеству и эффективности. Особенность Международной фармакопеи состоит в том, что основные усилия прикладываются к созданию монографий, актуальных для стран с низким и средним уровнем дохода, где может быть недостаточно ресурсов для разработки собственных фармакопей. В условиях глобализации лекарственные препараты, медицинские изделия и косметические средства часто импортируют из стран с разными стандартами регулирования и требованиями к медицинской продукции. При реагировании на чрезвычайные ситуации глобального характера в области общественного здравоохранения, такие как пандемия COVID-19, требуется оперативно проверять качество лекарственных средств и как можно быстрее с учетом интересов всех сторон обеспечить населению доступ к ним, что делает Международную фармакопею крайне необходимой

Shadow analysis: A method for measuring soil surface roughness

Erosion potential and the effects of tillage can be evaluated from quantitative descriptions of soil surface roughness. The present study therefore aimed to fill the need for a reliable, low-cost and convenient method to measure that parameter. Based on the interpretation of micro-topographic shadows, this new procedure is primarily designed for use in the field after tillage. The principle underlying shadow analysis is the direct relationship between soil surface roughness and the shadows cast by soil structures under fixed sunlight conditions. The results obtained with this method were compared to the statistical indexes used to interpret field readings recorded by a pin meter. The tests were conducted on 4-m2 sandy loam and sandy clay loam plots divided into 1-m2 subplots tilled with three different tools: chisel, tiller and roller. The highly significant correlation between the statistical indexes and shadow analysis results obtained in the laboratory as well as in the field for all the soil–tool combinations proved that both variability (CV) and dispersion (SD) are accommodated by the new method. This procedure simplifies the interpretation of soil surface roughness and shortens the time involved in field operations by a factor ranging from 12 to 20

Design and evaluation of advanced intelligent flight controllers

Reinforcement learning based methods could be feasible of solving adaptive optimal control problems for nonlinear dynamical systems. This work presents a proof of concept for applying reinforcement learning based methods to robust and adaptive flight control tasks. A framework for designing and examining these methods is introduced by means of the open research civil aircraft model (RCAM) and optimality criteria. A state-of-the-art robust flight controller - the incremental nonlinear dynamic inversion (INDI) controller - serves as a reference controller. Two intelligent control methods are introduced and examined. The deep deterministic policy gradient (DDPG) controller is selected as a promising actor critic reinforcement learning method that currently gains much attraction in the field of robotics. In addition, an adaptive version of a proportional-integral-derivative (PID) controller, the PID neural network (PIDNN) controller, is selected as the second method. The results show that all controllers are able to control the aircraft model. Moreover, the PIDNN controller exhibits improved reference tracking if a good initial guess of its weights is available. In turn, the DDPG algorithm is able to control the nonlinear aircraft model while minimizing a multi-objective value function. This work provides insight into the usability of selected intelligent controllers as flight control functions as well as a comparison to state-of-the-art flight control functions

Relationship between nano-architectured Ti1−xCux thin film and electrical resistivity for resistance temperature detectors

Ti1−xCux thin films were produced by the glancing angle deposition technique (GLAD) for resistance temperature measurements. The deposition angle was fixed at α = 0° to growth columnar structures and α = 45° to growth zigzag structures. The Ti-to-Cu atomic concentration was tuned from 0 to 100 at.% of Cu in order to optimize the temperature coefficient of resistance (TCR) value. Increasing the amount of Cu in the Ti1−xCux thin films, the electrical conductivity was gradually changed from 4.35 to 7.87 × 105 Ω−1 m−1. After thermal “stabilization,” the zigzag structures of Ti1−xCux films induce strong variation of the thermosensitive response of the materials and exhibited a reversible resistivity versus temperature between 35 and 200 °C. The results reveal that the microstructure has an evident influence on the overall response of the films, leading to values of TCR of 8.73 × 10−3 °C−1 for pure copper films and of 4.38 × 10−3 °C−1 for a films of composition Ti0.49Cu0.51. These values are very close to the ones reported for the bulk platinum (3.93 × 10−3 °C−1), which is known to be one of the best material available for these kind of temperature-related applications. The non-existence of hysteresis in the electrical response of consecutive heating and cooling steps indicates the viability of these nanostructured zigzag materials to be used as thermosensitive sensors.Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013 and Project PTDC/EEI-SII/5582/2014. A. Ferreira and C. Lopes thanks the FCT for Grant SFRH/BPD/102402/2014 and SFRH/BD/103373/2014. The authors thank financial support from the Basque Government Industry Department under the ELKARTEK Programinfo:eu-repo/semantics/publishedVersio