Voltage Regulation in a Buck Converter for an Unknown CPL: An Extended Feedback Control Design

This paper deals with the problem of the output voltage regulation in a buck converter for an unknown constant power terminal (CPL) which generates a nonlinear dynamical model that requires an efficient control technique. An extended feedback linearization (EFL) approach is proposed to regulate the voltage provided to the CPL. The main characteristic of the EFL control is that it is based on the linearization of the dynamical model around the desired operative point, making it equivalent in this point to the classical approximated feedback control design. However, the EFL, even if designed with the linearized model, provides a nonlinear feedback control law that extends the action area near the operating point with better performance than linear controllers. To estimate the unknown load value, the estimation technique known as the inverse and invariant approach is applied with the main advantage that the load estimation has exponential convergence to the real value of the CPL. Numerical simulations in the PLECs software for MATLAB/Simulink reveal the effectiveness of the proposed EFL control compared to the exact feedback linearization controller

Extended Feedback Linearization Control for Voltage Regulation in a Buck Converter with an Unknown Resistive Load

This paper deals with the control problem in a buck converter while considering an unknown resistive load. The control design is based on extended feedback linearization (EFL) theory, which allows finding a general control law equivalent to the approximated feedback control method when the state variables are at the desired equilibrium point. The main advantage of an EFL controller is that the final feedback gains are independent of the converter parameters if and only if all the capacitances and inductances of the converter are perfectly known. To define the resistive load value, the inverse and invariance estimation method was employed, aiming to ensure the exponential convergence of the real resistive value. Numerical comparisons with an integral-action, passivity-based control design demonstrate the effectiveness of the proposed EFL approach. All numerical simulations were conducted in the PLECs simulation tool of the MATLAB/Simulink environment. © 2023 IEE

In vitro Study of the Survival, Reproduction and Morphology of Daphnia pulicaria irradiated with a Low Energy Laser

Daphnia is a genus of crustaceans that is representative of freshwater communities. The species exhibit a high sensitivity to a wide range of toxic compounds so that they have been used internationally as biomonitors in toxicity tests to evaluate ecosystem conditions such as water quality. It is also a model genus in genetics, epigenetics and reproductive ecology. In this work, we used Daphnia pulicaria as a model to measure the effects of low-energy laser irradiation on survival, reproduction, and morphology variables of parental organisms and their offspring. We used (1) a single clone line of organisms to eliminate interindividual genetic variability; (2) individuals from more than 50 generations after the clone line was established, and offspring from the third brood onwards to dissipate maternal and epigenetic effects, and (3) neonates, those individuals of the species that have less than 48 hours of life, because they are the most sensitive stage to optical stimuli. We analyzed number of deaths, longevity, age at first reproduction, number of offspring per week, number of total offspring during all their life cycle, body size, size of the antennules, and length of the apical spine of the 4th and 5th brood of the irradiated individuals, who were exposed to a blue laser stimulus of 405 nm for 25 minutes with a power of 40 mW at a distance of 50 cm, compared to those of the control (non-irradiated) group

Pricing and quality investments in a mixed brown-green product market

Sustainable Supply Chain Management (SSCM) has assumed a position of prominence for academics and industry over the last two decades. The sustainability literature shows that typically manufacturers aim to optimize their pricing and greening level decisions in a mixed (green and brown) consumer market. In this work, we capture a manufacturer’s classic dilemma on the pricing of green and brown products, and greening investments, while subject to budget constraint. We compute and analyze the variations of optimal decisions over time. Our findings underscore the importance of investing in greening technologies and learning for the survival of green products. Furthermore, we show that a manufacturer’s optimal pricing strategy is to enter the market with a lower price for the green product and to increase it over time, eventually, surpassing the price for the brown product. Our analysis reveals that the greening level attraction can nullify the effect of a high price on the green product, resulting in higher green demand than brown. Higher green product demand is a win-win situation for both the manufacturer and the environment

Protocolos de genómica para monitoreo ambiental asociado a acciones de respuesta por impacto o contingencia ambiental formalizados y listos para ser transferidos a usuarios interesados

En este documento se describen los aspectos más relevantes para aplicar la técnica de metabarcoding en estudios de biodiversidad. En la primera sección se realiza un recuento de los aspectos relevantes en el diseño experimental propios a la técnica. En la segunda se plantea una propuesta de protocolo para la aplicación del metabarcoding, incluyendo la toma de muestra, el procesamiento molecular y el procesamiento o depuración bioinformática. El diseño de muestreo y los análisis ecológicos no son incluidos desde que estos son totalmente contexto-dependientes. En la tercera sección se describe un estudio de caso usando metabarcoding en la caracterización de microorganismos de una zona altamente contaminada por actividades relacionadas a la extracción convencional de hidrocarburos. En la cuarta parte se realiza una revisión del potencial uso del metabarcoding en el monitoreo ambiental a través insectos. Finalmente, en la quinta y última parte se exponen algunas de las perspectivas y limitaciones del uso de la técnica en Colombia. El objetivo de este documento es fomentar el uso de esta herramienta en escenarios colombianos, generando datos cuantitativos de diversidad que puedan ser incluidos en la toma de decisiones.Bogotá, ColombiaPrograma de Ciencias de la Biodiversida

MARCO variants are associated with phagocytosis, pulmonary tuberculosis susceptibility and Beijing lineage

Macrophage receptor with collagenous structure (MARCO) has an important role in the phagocytosis of Mycobacterium tuberculosis (M. tuberculosis). We hypothesized that MARCO polymorphisms are associated with phagocytosis, tuberculosis (TB) disease susceptibility and presentation, and infecting lineage. We used a human cellular model to examine how MARCO genotype mediates the immune response; a case-control study to investigate tuberculosis host genetic susceptibility; and a host-pathogen genetic analysis to study host-pathogen interactions. Two MARCO heterozygous (AG) genotypes (single-nucleotide polymorphisms rs2278589 and rs6751745) were associated with impaired phagocytosis of M. tuberculosis trehalose 6,6'-dimycolate-cord factor and β-glucan-coated beads in macrophages. The heterozygous genotypes of rs2278589 and rs6751745 were also associated with increased risk of pulmonary TB (PTB; rs2278589, P=0.001, odds ratio (OR)=1.6; rs6751745, P=0.009, OR=1.4), and with severe chest X-ray abnormalities (P=0.007, OR=1.6). These two genotypes were also associated with the Beijing lineage (rs2278589, P=0.001, OR=1.7; rs6751745, P=0.01, OR=1.5). Together, these results suggest that MARCO polymorphisms may regulate phagocytosis of M. tuberculosis and susceptibility and severity of PTB. They also suggest MARCO genotype and Beijing strains may interact to increase the risk of PT

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE