A seca-da-mangueira no Estado do Piauí: situação atual e recomendações de controle.

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Parametric Amplification in the Dynamic Radiation Force of Acoustic Waves in Fluids

We report on parametric amplification in dynamic radiation force produced by a bichromatic acoustic beam in a fluid. To explain this effect we develop a theory taking into account the nonlinearity of the fluid. The theory is validated through an experiment to measure the dynamic radiation force on an acrylic sphere. Results exhibit an amplification of 66 dB in water and 80 dB in alcohol as the difference of the frequencies is increased from 10 Hz to 240 kHz

Avaliação do stress parental em mães de crianças com perturbação de hiperatividade com défice de atenção

Introdução: Pretendeu-se identificar os níveis de stress nas mães de crianças e adolescentes com perturbação de hiperatividadecom défice de atenção e verificar se existe uma associação entre o stress percecionado por estas mães e o funcionamento familiar.Métodos: Foram utilizados o índice de stress parental, versão reduzida, que caracteriza o stress parental total de acordo comtrês dimensões (dificuldade parental, interação pais / criança e criança difícil), e a escala de avaliação da adaptabilidade e coesãofamiliar, que classifica as famílias em equilibradas, meio-termo ou extremas.Resultados: Participaram neste estudo 89 mães. Obtiveram-se valores médios no questionário índice de stress parental acimado percentil 85 (valor de cutoff) nas subescalas interação disfuncional criança-pais, criança difícil e no valor de stress total.Verificou-se ainda que havia uma forte correlação entre stress total e as três subescalas, isto é, mães com níveis mais elevadosde stress tendem a ter uma maior perceção de dificuldade parental, de interação disfuncional com a criança e de criança difícil.Não se verificaram diferenças estatisticamente significativas entre o tipo de família (equilibrada versus meio-termo ou extrema,ou monoparental versus nuclear) e o stress parental.Discussão: Concluiu-se que as mães das crianças com perturbação de hiperatividade com défice de atenção apresentam elevadosníveis de stress, o qual parece advir fundamentalmente das características da criança, que é percecionada como sendouma criança difícil, e de uma interação disfuncional entre os pais e a criança. Não parece haver relação entre o nível de stressexperienciado por estas mães e a funcionalidade ou organização da famíli

Mothers' eating styles influence on their feeding practices and on their children's appetite traits

Background: Overweight and obesity in children and adolescents has become an important public health concern in the last decades. To study the way mothers and childrens behavioral factors interact with each other, influencing eating and body weight, may provide information to be used in preventive and treatment strategies.Goals: To study the association of mothers eating style on their feeding behavior and on their childrens eating behavior.Methods: Cross-sectional observational study with a non-probabilistic sample of mother and child dyads (from three schools). Mothers eating behavior (assessed with Dutch Eating Behavior Questionnaire scale; DEBQ) was classified and they were grouped into three eating styles: restrictive, emotional-external or neutral styles. Mothers feeding restriction, pressure to eat and concern about childs weight were assessed (through the Child Feeding Questionnaire; CFQ). Finally, mothers classified their childs appetite behaviors (with the Childrens Eating Behaviour Questionnaire; CEBQ).Results: Overall, participated 279 mothers, aged between 23 and 59 years (Mean= 38.03 years, SD=5.09) and respective children (n=279), aged between 6 and 13 years (Mean= 9.43 years, SD= 1.35), 140 of those were females (50.2 %). Associations between mothers eating style, their feeding behaviors and childrens appetite traits showed that restrictive and emotional-external eating mothers had higher scores of CFQ and CEBQ items related with obesity, when compared to neutral eating style mothers. Mothers feeding restriction and childrens weight concern associated positively with childrens food approach behaviors (enjoyment of food, food responsiveness, emotional over-eating), and negatively with food avoidance behaviors (satiety responsiveness and slowness in eating). On the contrary, pressure to eat associated positively with food avoidance behaviors and negatively with food approach behaviors. Mothers concern about child weight and feeding restriction were positively associated with CEBQ subscales that reflect food approach and negatively associated with subscales that reflect food avoidance. Pressure to eat had the symmetric associations. Discussion: Results support the hypothesis of the transmission of eating behaviors that promote obesity from mothers to children, and have implications both for prevention and children and adolescents obesity treatment. Therefore, mothers should be a part of the intervention when treating their children obesity</jats:p

Mould redesign and analysis for the production of a micro-accelerometer

In this paper we present an alternative fabrication method based on polymeric materials and technologies for three-axis thermal accelerometers. The device is composed by four microinjected parts forming an external structure responsible for the coupling and sealing of a polymeric membrane. The membrane contains and protects the heater and thermoresistors and is fabricated by microtechnologies. The fabrication process was successful although some issues were noticed in the mould during the microinjection process. Regarding the ejection side, a redesign was done to first assure the locking of the micro-parts on the movable side of the mould and second to improve the extraction of the parts avoiding its deformation. Overheating of the mould and polymer freezing on the injection nozzle were the main issues found on the injection side of the mould. Three different injection nozzle designs and two different fabrication materials were analyzed and simulated. The results show that an intermediate injection nozzle design using Ampcoloy 940® as construction material can improve the maintenance of the established temperature values for both mould and injection nozzle

Novas doenças de plantas ornamentais no Estado do Ceará.

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Aligned carbon nanotube-based sensors for strain monitoring of composites

This paper presents a proof of concept of an aligned carbon nanotube (CNT) based strain sensor tested on the surface of a conventional aeronautic laminate. Two type of strain sensors were produced, type S and type T, in which the CNT alignment was parallel (Y) and transversal (X) to strain direction, respectively. Their electrical resistance response was thoroughly evaluated during cyclic tensile tests. Despite some disparities of the relative electrical resistance behavior in specific strain cycles, probably due to one-off interferences in the CNT conductive mechanism, the obtained gauge factor (GF) values were quite stable. Also, the electrical resistance anisotropy was evaluated and its opposite behavior when the samples were strained in Y- and X-directions may be used as strain direction indicator. Being able to quantify and indicate strain direction with just one 10 x 10 mm CNT patch, this sensor has proven to be suitable for strain sensing applications, namely for structure health monitoring of advanced composites.- Manuscript received March 4, 2021; revised March 25, 2021; accepted March 31, 2021. Date of publication April 5, 2021; date of current version June 30, 2021. This work was supported in part by the Project "Introduction of Advanced Materials Technologies Into New Product Development for the Mobility Industries-IAMAT," under the MIT-Portugal program exclusively financed by Fundacao para a Ciencia e Tecnologia "FCT" under Grant MITP-TB/PFM/0005/2013 and in part by the North Portugal Regional Operational Programme (NORTE 2020) under the Portugal 2020 Partnership Agreements through the European Regional Development Fund (ERDF) Project "Technologies for Sustainable and Smart Innovative Products (TSSiPRO)" under Grant NORTE-01-0145FEDER-000015. The associate editor coordinating the review of this article and approving it for publication was Dr. Cheng-Sheng Huang. (Corresponding author: Ana Raquel Santos.

Carbon nanotubes based multi-directional strain sensor

In this work a new carbon nanotubes (CNT) based multi-directional strain sensor capable of quantifying and indicate strain direction is foreseen. This work investigates the electromechanical behavior of an aligned CNT sensing patch strained at 45◦ in order to validate its multi-directional sensing capability. Vertically aligned CNT forests are produced by chemical vapor deposition (CVD) and then mechanically knocked down onto polyimide (PI) films. Two configurations, diamond (D sample) and square (Sq sample), are considered. The relative electrical resistance (ΔR/R0) and the electrical anisotropy (RB/RA) upon strain increments are analyzed and compared to previous work results (0◦ and 90◦ strain direction). Both 45◦ samples, D and Sq, are sensitive to strain. A correlation between electrical anisotropy behavior and strain direction (0◦, 45◦ and 90◦) is established. The results show that with only an aligned CNT small patch it is possible to quantify and indicate strain in three directions.This work was partially funded under the project “IAMAT – Introduction of advanced materials technologies into new product development for the mobility industries”, with reference MITP-TB/PFM/0005/2013, under the MIT-Portugal program exclusively financed by FCT – Fundação para a Ciência e Tecnologia. This work was also co-financed by national funds through FCT – Fundação para a Ciência e Tecnologia, with the scope of projects with references UIDB/05256/2020 and UIDP/05256/2020”