bluuebunny/crossref_metadata_2025 huggingface dataset:
AVALIAÇÃO DO ATENDIMENTO DE PACIENTES COM SUSPEITA DE SÍNDROMES CORONÁRIAS AGUDAS COM BASE EM PROTOCOLO E ALGORITMO ESPECÍFICO
Authors: Santos Frinye , Carvalho Ana Lara , Menichele Jéssica , Tertuliano Maria Clara , Carvalho Felipe , Moreira Humberto
Published: December 2018

Objetivo: Verificar a efetividade no atendimento de emergência ao paciente com dor torácica e suspeita de síndrome coronária aguda (SCA) no Hospital Evangélico Goiano de Anápolis, segundo as metas preconizadas pelas diretrizes da Sociedade Brasileira de Cardiologia para SCA, descrever o perfil sociodemográfico e as características clínicas dos pacientes admitidos; descrever o tempo porta-ECG (eletrocardiograma) e ECG-laudo médico; descrever a realização ou não do AAS (ácido acetilsalicílico) na suspeita de SCA; descrever o tempo porta-balão; analisar os desfechos clínicos e a correlação dos mesmos com as variáveis expressas acima.

Métodos: Trata-se de um estudo descritivo, observacional e retrospectivo. Resultados: Foram analisados 175 pacientes, não previamente selecionados, no período de outubro de 2015 a março de 2016 submetidos ao protocolo de dor torácica. A idade média dos pacientes foi de 56,3 anos e 61% eram do sexo masculino. As médias do tempo porta-ECG e ECG-laudo foram de 5,8 e 6,4 minutos, respectivamente. O número daqueles com SCA e que receberam AAS foi de 58.3% para supradesnivelamento de segmento ST e de 93.8% naqueles sem elevação de ST. Ao todo, 165 pacientes (94,3%) receberam alta hospitalar e 10 pacientes (5,7%) vieram à óbito.

Conclusões: Embora as características da população atendida e do atendimento ao paciente com SCA se assemelhem aos de outros registros nacionais, pode-se verificar oportunidades de adequação para que esta assistência esteja totalmente dentro das metas preconizadas pelas diretrizes atuais.
ATEROSCLEROSE DE CARÓTIDA: ASSOCIAÇÃO ENTRE O LADO ACOMETIDO COM FATORES DE RISCO E DOENÇAS SISTÊMICAS
Authors: Dos Santos Silva Teófilo Dorneles Claro , Pimentel Laís dos Santos , Barbosa Ronan Lacerda , Santos Marlon Ferreira , De Carvalho Felipe Rodrigues , Dos Santos Leonardo Hunaldo , De Matos Junior Edem Moura
Published: December 2018

Introdução: A aterosclerose é uma doença degenerativa de etiologia multicausal. Diferentes fatores de risco (genéticos e adquiridos) atuando em conjunto podem determinar sua ocorrência. Objetivo: Considerando a importância epidemiológica da aterosclerose, resolveu-se estudá-la por meio da ultrassonografia e observar sua associação entre o lado acometido (direito, esquerdo, ambos os lados) com fatores de risco, como: idade, sexo, hipertensão arterial, tabagismo e diabetes melito. Metodologia: Os dados foram obtidos a partir da análise de fichas de atendimento, disponibilizadas por uma clínica particular de Imperatriz – MA, que oferece o serviço de doppler de carótida, no período de janeiro a dezembro de 2016. O exame ultrassonográfico teve como objetivo a localização e quantificação de lesões ateromatosas das carótidas. Resultado: Foram estudados 50 indivíduos, cuja a faixa etária variou de 42 a 86 anos, com idade média de 69,72 anos (± 9,43), dos quais 31 (62%) eram do sexo feminino e 19 (38%) masculino. Dessa população, 13 (26%) eram portadores de diabetes melito, e 11 (22%) eram tabagistas, 38 (76%) indivíduos eram hipertensos e 22 (44%) tinham história pregressa de acidente vascular cerebral. Conclusão: Embora os estudos evidenciem diferenças no grau de desenvolvimento aterosclerótico quando comparado o lado da artéria carótida acometida, demonstra-se não haver correlação específica ente o lado acometido (direito, esquerdo, ambos) com os fatores de risco (sexo, tabagismo) e doenças sistêmicas (acidente vascular cerebral, diabetes melito e hipertensão).
Inquiring, Inventing and Integrating: Applying Human-Centered Design to the Challenges of Future Government
Authors: Junginger Sabine
Published: December 2018

The challenges of future government involve opportunities for the conception, planning and delivery of new government services. Applying the principles and methods of human-centered design offers an alternative path for how we go about designing them. Inquiring into existing design practices allows for the discovery of new forms of design thinking and the application of new design methods and processes. A focus on human experience and human interaction promotes innovation and inventions, newly integrates public organizations and directly contributes to the creation of public value by benefitting the individual, government and society.
Inovação pedagógica na universidade
Authors: Campani Adriana , Silva Rejane Maria Gomes da , Parente Paulina Maria Mendes
Published: December 2018

O cenário contemporâneo vem provocando a emergência de novas atitudes, novos valores e outros saberes, que exigem, por sua vez, uma universidade capaz de refletir sobre a sua própria relação com o conhecimento. Acredita-se ser a Extensão Universitária o lócus privilegiado para promover essa reflexão. Nela podemos encontrar caminhos para a produção de um conhecimento inovador, intercultural e includente, abrindo-se para a construção de uma universidade mais aberta, ética, democrática, solidária e que possibilite a educação ser pensada de forma mais transgressora e autônoma. A emergência de uma formação universitária inovadora perpassada pela Extensão contribui para construção e socialização de conhecimentos significativos e em constante diálogo com os diversos setores da comunidade, possibilitando um currículo capaz de romper e reconhecer outras formas de produção de saberes, incorporar a dimensão sócio-histórica do conhecimento; buscar a gestão partilhada dos atos pedagógicos com ações reflexivas perante o conhecimento, compreender que o conhecimento com algo complexo e passível de reconfigurações e colocarem-se como mediadores includentes das relações socioafetivas como condição da aprendizagem. Compreende-se que a inovação pedagógica na universidade requer ruptura paradigmática, inovação curricular e fortalecimento da extensão universitária.
De la dépossession à l’expérience de la possession dans Meursault, contre-enquête de Kamel Daoud
Authors: Badr Maha
Published: December 2018

There is a clear correlation between the text of L'Étranger of Camus and Meursault, contre-enquête of Kamel Daoud, fertility is sure. Daoud, living in a previously colonised minority context, manipulates Camus’ memorised coded speech to make himself heard. Is it a confrontation or a duplication of speech? The writing attempts to find points of instability and mobility likely to ruin the ‘temple’ of a monumental literary building. Emphasis will be placed on this gesture of appropriation and the polyphony of the text sited between recovery and transgression. This play of intertextuality creates a discursiveness that destabilizes the reader. The reading follows a retroactive investigation that goes beyond an experience of negativity by traversing a path between myth and fantasy that visualises a peaceful relationship between East and West.
La fête et le spectacle carnavalesques dans Le Mât de cocagne (1979) et Hadriana dans tous mes rêves (1988) de René Depestre
Authors: Alvarez Domenech Irene
Published: December 2018

The aim of this article is to bring together two of René Despestre’s novels, Le Mât de cocagne (1979) and Hadriana dans tous mes rêves (1988), and place them within the tradition of the carnivalesque as it was discussed by Mikhail Bakhtin in L’œuvre de François Rabelais et la culture populaire au Moyen Âge et sous la Renaissance. By taking into account this wider perspective, I intend to show that the presence of a diegetic spectacle reinforces the subversive value of the two works by including a moment of utopian relief that invites both the characters and the readers to engage in a fight for freedom.
Caribbean Contemporary Poets and Graphic Artists Moored at the Venice Biennale of Architecture 2018
Authors: Spencer Matz Margaret
Published: December 2018

The Teatrino del Mondo of Aldo Rossi, a performance space set on a barge that could be reached by boat (1979-80), became an iconic metaphor for the first Venetian Biennale of Architecture. At the Venetian Biennale of Architecture 2018, this metaphorical representation was engaged by Caribbean contemporary poets Lasana M. Sekou and Charles Matz II and visual artists Cozbi Sanchez Cabrera and Jean-Ulrick Désert. In exploring ties that link the vessels of Caribbean contemporary literature and art to Venice, witness is the audacity of their opera, created while confronting intensifying natural disasters such as earthquakes and hurricanes, and recalling horrifying unnatural conditions of Slavery and war. The artists participated in collateral events in which poetry or visual art intersected marvellously with Venetian idioms.
Análisis de experiencias de innovación docente universitarias sobre evaluación
Authors: Cano García María Elena , Pons Seguí Laura , Lluch Molins Laia
Published: December 2018

Se analizan las experiencias relativas a la evaluación de aprendizaje contenidas en actas de innovación docente de los años 2011-2015, con el objetivo de conocer sobre qué aspectos de la evaluación se está innovando y a qué ámbitos de conocimiento pertenecen. Con este propósito se han establecido seis hipótesis en base a la literatura previa y, para verificarlas, se han seleccionado actas de congresos de innovación docente pertenecientes a universidades públicas del territorio español. Se ha analizado el instrumento o estrategia sobre el que versa la innovación y los agentes evaluativos, se ha identificado el tipo de asignatura, el campo de conocimiento y las estrategias de recogida de información para valorar sus resultados. Los datos obtenidos se han explorado de forma descriptiva. Los resultados del análisis muestran que el campo de Humanidades es donde se realizan menos innovaciones; la mayoría de innovaciones se desarrollan en el primer curso de grado; estas tienden a incorporar diversos agentes evaluativos; y el método más utilizado para valorar los resultados de una innovación son los cuestionarios de satisfacción y percepción de aprendizaje. No se ha podido comprobar si la mayoría de las innovaciones docentes están vinculadas a proyectos de innovación docente reconocidos institucionalmente, ni si estas se realizan con grupos reducidos de estudiantes. En conjunto, todo ello ofrece un panorama acerca del estado de las innovaciones en educación en España y proporciona una mayor comprensión de la evaluación de los aprendizajes en educación superior en la actualidad.
Modelo de ecuaciones estructurales y validación del modelo de formación TPACK: Estudio empírico
Authors: Cabero-Almenara Julio , Pérez Díez de los Ríos José Luís , Llorente-Cejudo Carmen
Published: December 2018

Resumen:Se analiza, mediante el modelo de ecuaciones estructurales, la viabilidad y validez del modelo TPACK y de las interacciones que se establecen, así como las del instrumento de diagnóstico utilizado para ello. La muestra estuvo conformada por 1.368 docentes de diferentes países latinoamericanos, y los instrumentos utilizados para el diagnóstico del TPACK fueron varios, centrándose en los cuestionarios, la observación no participante y la entrevista, utilizándose en este caso el elaborado por Schmidt et al. (2009).El principal propósito del estudio, que era la validación de un modelo del TPACK se ha visto confirmado, y se puede señalar que existe un modelo significativo para poder sugerir propuestas para la capacitación de los docentes en el uso educativo de las TIC, y para comprender su funcionamiento educativo. Se demuestra la eficacia del modelo, las posibilidades que ofrece la metodología de las ecuaciones estructurales y se valida un instrumento de análisis del TAM hacia la RA. Al mismo tiempo, los hallazgos sugieren que las relaciones que se pueden establecer entre las diferentes dimensiones del TPACK son más complejas que lo presentado en el modelo, lo que requiere una profundización en su conceptualización y comprensión.
La “técnica de clarificación 5-5-5”, un método natural para el tratamiento de material vegetal
Authors: Arambarri Ana M.
Published: December 2018

El objetivo de esta publicación es dar a conocer, como alternativa, una técnica de clarificación, sencilla, económica, sin agresividad para el material vegetal y que puede ser empleada para la investigación de diferentes órganos y tejidos. Hace algunos años, se comenzó a ensayar en el Laboratorio de Morfología Comparada de Espermatófitas (LAMCE), una técnica de diafanización de hojas de plantas. La misma se desarrolló ante la búsqueda de un método de clarificación que permitiera mantener la orientación del material y no fuera tan agresivo para los materiales pequeños y delicados. Como resultado se obtuvo un método natural con las características buscadas.
Cybersecurity Policy as if “Ordinary Citizens” Mattered: The Case for Public Participation in Cyber Policy Making
Authors: Shane Peter M.
Published: December 2018

Given the ubiquity of computer networks and our reliance as a society on their integrity and robustness, the quality of cyber-security is an issue that affects everyone. Yet, cyber-security policy making has remained almost entirely within the purview of lobbyists and technical experts. This article argues for both the plausibility and normative imperative of greater public participation in cyber policy making.
Risk Factors and Outcome of Patients with Obstetric Anal Sphincter Injuries (OASIS)
Authors: Bhatt Rabindra D. , Sitaula S. , Pradhan T. , Manandhar T. , Basnet T.
Published: December 2018

Background: Anal incontinence is an embarrassing condition that is largely underreported. Obstetric anal sphincter injuries are the most important etiological factors. Anal sphincter injury during delivery is considered to be one of the major risk factors for fecal incontinence in women. After anal sphincter injury at the time of delivery, up to 50% women have complaints of fecal incontinence, mainly because of persisting sphincter defects.

Objectives: To evaluate the risk factors for the occurrence of obstetric anal sphincter injuries during vaginal delivery. To evaluate the outcome of patients with obstetric anal sphincter injuries.

Methodology: A retrospective descriptive study was conducted from 2014 to 2016. Data of all patients with Obstetric Anal Sphincter Injuries (OASIS) over 3 years was collected from the medical record section after ethical clearance from Institutional Review Committee (IRC), BPKIHS. The data was entered in the excel sheet and analyzed using SPSS 17.

Results: The Most important risk factor of OASIS was operative vaginal delivery (vacuum assisted vaginal delivery), followed by birth weight of the baby greater than 3.5 Kg and primigravida.

Conclusion: Patients undergoing operative vaginal delivery, primigravida and birth weight greater than 3 kg are the important risk factors for OASIS. So, patients with these conditions should be handled carefully during second stage of labor to prevent the occurrence of OASIS.
Aprendizagem baseada em projetos na perspectiva dos alunos
Authors: Cervi Uzun Maria Luisa , Pugliesi Jaqueline Brigladori , Roland Carlos Eduardo de França
Published: December 2018

No contexto de discussões sobre metodologias ativas, especialmente no ensino superior, o presente trabalho objetivou investigar, na perspectiva dos alunos, a sua aprendizagem quando se utiliza o método aprendizagem baseada em projetos (ABP). Optou-se por utilizar o método misto de estudo (quantitativa e qualitativa), de acordo com Galvão, Pluye e Ricarte (2017). Para isso, foi enviado um questionário com 20 itens na escala Likert para verificar o nível de concordância e um item para resposta aberta objetivando fazer análise das mensagens escritas pelos alunos num curso de Análise e Desenvolvimento de Sistemas de uma Faculdade de Tecnologia envolvendo as disciplinas de Estatística Aplicada, Interação Humano Computador, Engenharia de Software e Linguagem de Programação. Este artigo é pautado nas principais teorias da aprendizagem de Lev Vygotsky (1896-1934), John Dewey (1859-1952), Carl Rogers (1902-1987) e David Ausubel (1918-2008). Os dados permitiram verificar, na perspectiva dos alunos, aspectos pedagógicos como: o seu grau de satisfação, autonomia, o papel do professor, entre outros.
Institucionalização do toyotismo: aliança entre academia e mercado
Authors: Vicente João Pedro Aparecido , Gonçalves Neto Wenceslau
Published: December 2018

Este artigo aborda a dicotomia estabelecida entre os usos da educação na conjuntura globalizada neoliberal, na qual a busca da erudição disciplinar se contrapõe ao atendimento das necessidades concretas do mercado de trabalho. Objetiva-se, neste texto, demonstrar a coerência entre os valores afins ao perfil toyotista de ordenação do trabalho e os pressupostos socialmente institucionalizados a partir da reestruturação econômica estimulada pela ideologia do livre mercado. Numa perspectiva estruturalista, busca-se extrair sentido das relações entre o Estado, os agentes econômicos hodiernos e a sociedade, com destaque para os usos das formações acadêmica e profissional como catalisadoras da adesão às condutas oportunas ao projeto dos dirigentes da coligação público-privada.
Precjepljivanje starih stabala maslina
Authors: Prgomet Željko , Prgomet Iva
Published: December 2018

Istraživanje je obavljeno na stablima maslina sorte Maurino starosti 7 godina. Precjepljivanje je obavljeno sa sortama Buža, Istarska bjelica i Pendolino krajem travnja 2011., stavljanjem plemki pod koru. U nasadu su se tijekom vegetacije obavljale sve potrebne agrotehničke mjere, od međuredne obrade tla do zaštite od bolesti i štetnika. Tijekom vegetacije smo pratili primitak cijepljenja i mjerili vegetativni porast izboja na plemkama po sortama. Također smo pratili utjecaj grana “hraniteljica”, od kojih smo neke i prstenovali, na postotak primitka cijepljenja, kao i na vegetativni porast novih izboja. Tijekom jednogodišnjeg praćenja i mjerenja, ustanovili smo da je sorta glavni čimbenik koji utječe na dužinu porasta novih izboja. Postotak primitka je bio 95%. Kod stabala s ostavljenim granama “hraniteljicama” bilo je manje izboja na primarnim granama i deblu precjepljivanih stabala
Utrošci energije i radni učinci kombajna za vađenje krumpira
Authors: Sito Stjepan , Kušec Vlado , Šket Branko , Očić Vesna , Džaja Vladimir , Brečko Natalija , Brkić Robert , Palinić Blanka
Published: December 2018

Krumpir se ubraja u jednu od četiriju strateški najvažnijih namirnica u svijetu. U Hrvatskoj se krumpir najviše uzgaja u Slavoniji i Međimurju gdje je posljednjih nekoliko godina prinos u porastu, ali još uvijek značajno ispod prosjeka zapadnoeuropskih zemalja. Neki od glavnih razloga nekonkurentnosti i neisplativosti proizvodnje na hrvatskom tržištu su: visoke cijene repromaterijala i velika ulaganja u modernizaciju mehanizacije. Cilj rad je utvrditi razinu utroška energije i radnih učinaka kombajna za vađenje krumpira. Kako bi se troškovi proizvodnje sveli na minimum potrebna je suvremena mehanizacija koja smanjuje vrijeme rada, a povećava radni učinak i prihode.
U radu su prikazani rezultati terenskog mjerenja utroška energije i radnih učinaka kod različitih izvedbi kombajna za vađenje krumpira. Analizirani su troškovi vađenja krumpira, a oni su se odnosili na troškove goriva i radnika, bez amortizacije strojeva.
Control of output mode and passband location of an overmoded defected coaxial Bragg structure
Authors: Lai Ying-Xin , Yang Lei , Zhang Shi-Chang
Published: December 2018

By making use of coupled-wave theory, the transmission characteristics of a defected coaxial Bragg structure which operates in the vicinity of 100 GHz are investigated. Results reveal that the overmoded operation of the example structure excites serious interaction among the operating mode and its neighboring modes, which spoils the passband structure and causes hybrid-mode transmission. However, single-mode output can be ensured by applying Hamming-window-function distribution to the ripple amplitude of the example structure, and one or more desired narrow passbands can be generated and controlled by adjusting the localized ripple defect or/and the initial phase difference between the outer-wall and the inner-rod ripples. These peculiarities provide potential applications of defected coaxial Bragg waveguides in constructing high-Q open resonators and narrow passband filters in the sub-terahertz and terahertz frequency ranges.
Structural analysis and design of micro-stirrer driven at a requested frequency for thrombus dissolution
Authors: Ajoudanian Mohammad , Jiang Zhongwei , Morita Minoru
Published: December 2018

This paper is concentrated on analysis and design of the structures of the micro-stirrer which have high performance at a requested frequency for thrombus dissolution. In this paper the new type structure of micro-stirrer which transmits the longitudinal elastic wave through catheter and converts to a bending motion at the tip stirrer is described first in order to get high performance of thrombus dissolution. Next how to design the structure which can be driven at a requested frequency without reduce the performance, because for dissolution of different type of thrombus it is necessary to drive micro-stirrers in a high performance frequency and with a certain deflection. To design and analysis the optimum structure, the modal analysis and harmonic analysis are carried on with the aid of FEM simulation. The results showed that it is possible to change the structures of the micro-stirrer to fit the requested driven frequency with keeping the high performance. The results also indicate that since the variations of design parameters are restricted rigidly, using the numerical simulation with proposed analysis model is a very efficient way to study the design of desirable structures.
Efficient methods for the computation of Pollaczek integrals in the magnetic field
Authors: Xiang Shuhuang , Ma Junjie
Published: December 2018

Calculation of the Pollaczek integral is very important in evaluating the magnetic field in air generated by an underground conductor. This paper provides an efficient algorithm to calculate these integrals by splitting the semi-infinite range into two parts, where the integral tail is evaluated by complex integration methods, and the integral on the finite segment is calculated by the Clenshaw-Curtis quadrature. The computational cost remains the same regardless the frequency, and the higher the oscillation the better the accuracy of the calculation. The efficiency and accuracy are tested by numerical examples.
Enhancement of conductometer functions with the measurements of surface roughness
Authors: Dziczkowski Leszek
Published: December 2018

The paper describes an innovative calibration method that makes it possible to efficiently measure the conductivity of workpieces with rough surfaces, where standard specimens with the already known properties are used for calibration. The calibration process leads to the determination of equivalent parameters of a probe. The measurements results are processed on line with the use of a simple mathematical model for the considered phenomenon. Finally, the determined conductivity value only slightly depends on the surface condition of the examined workpiece. During the conductivity determination there was calculated a parameter–namely, the eddy-current factor of surface roughness–that compensates the impact of the surface roughness. The parameter can be treated as a specific roughness factor of the eddy-currents. The factor has been determined for several samples with already known mechanical values obtained with the help of Ra and Rz methods.
Hardy's Multi-Quadric method of calibrating a wireless electromagnetic localization system for intestinal micro-devices
Authors: Guo Xudong , Yan Rongguo , Wang Cheng
Published: December 2018

A wireless electromagnetic localization method for tracking a medical micro-device in the gastrointestinal tract has been proposed and a prototype for the localization system has been developed. In the electromagnetic localization system, several excitation coils were mounted above the abdomen of human body to generate a varying electromagnetic field one by one. Then a wireless magnetic sensor was used to measure the magnetic field strength at the location of the micro-device. Thus the position and orientation of the micro-device could be obtained by solving the inverse problem of magnetic fields. In order to improve the localization precision, a global error correction technique based on the Hardy's Multi-Quadric scattered data interpolation method was investigated to correct the static errors. In the calibration experiment, dependencies between true locations of the micro-device and the corresponding tracked locations within the operational space were established. Based on these data sets, the Hardy's Multi-Quadric correction function was derived. The experimental results show that the localization error can be greatly reduced by using the Hardy's Multi-Quadric correction method. The advantage of the approach is that it allows for smooth continuous mapping from the tracked space to the true space within the entire tracked space.
Parameters determination of the modified J-A model with an optimization algorithm
Authors: Cong Haoxi , Zou Liang , Zhang Li , Li Qingmin
Published: December 2018

J-A model is widely used in hysteresis modeling as well as performance simulation of the magnetic materials. To achieve preferable adequacy, a modified J-A model is given, however, accurate solution of the parameters is very important for the modified J-A model, especially for over-determined nonlinear equations. In response to solving the over-determined nonlinear equations, this paper first turned the problem of the over-determined nonlinear equations into solving the minimum value of a multivariate function by means of the least square method. While the multivariate function is of high nonlinearity (the function is not continuous and the matrix of the partial derivatives is singular), solution methods using derivative calculation were abandoned, and the direct seeking methods with no derivative calculations(simplex algorithm) were involved to solve the problem. In the end the solution was validated with the use of the genetic algorithm and the simulated annealing algorithm.
Evaluation of lightning current using inverse procedure algorithm
Authors: Izadi M. , Ab Kadir M.Z.A. , Askari M.T. , Hajikhani M.
Published: December 2018

In this study an inverse procedure algorithm is proposed in the time domain to evaluate lightning return stroke current based on measured electromagnetic fields at an observation point. The proposed method considers on all electromagnetic fields components and can evaluate full shape of current, velocity and constant parameters of current models in contrast with previous studies. In order to validate the proposed method, a set of measured electromagnetic fields are applied on proposed algorithm and the evaluated currents are compared to the corresponding measured current as well as the results are discussed accordingly. The proposed method can be used for preparing of current data bank that is very useful for considering on lightning effects on the power lines and setting appropriate protection levels on the power systems.
A NDE strategy based on a database for evaluation of the anti-corrosive coating on curved steel bases of various sizes using ECT signals
Authors: Zhang Dongli , Wang Zhaoba , Chen Zhenmao
Published: December 2018

The anti-corrosive coating in pipeline and oil tanker is taken as a crucial component in petroleum industry and needs a robust NDE tool to evaluate its thickness. For the thick coating on the curved steel bases of various sizes, the eddy current sensor's evaluation capability for thick coating and the influence of the test-piece sizes on the evaluation precision are two key problems had to be solved. Taking into account the dimension effect of the sensor on signals, a wide-range sensor was designed and applied to the coating evaluation. The relationship between coil responses and liftoff was investigated and a NDE strategy based on a polynomial coefficient database was proposed to cope with the influence of test-piece sizes. Its applicability was verified by simulation results.
Support forces in a synchronized rotating spring-mass system and its electromagnetic equivalent
Authors: Provatidis Christopher G. , Gamble Michael A.
Published: December 2018

This paper deals with the dynamic analysis for the calculation of the support forces in a rotating elastic rod when subjected to simple types of axial forces. For simplicity the model starts with a linear straight spring and a lumped mass and expands into a distributed system. The analysis shows a shift in the natural frequency of the support forces, due to rotation and additional axial oscillations, these are highly influenced by both the axial and the shear forces, which are induced by the centripetal and Coriolis forces, respectively. Based on this finding, the paper shows that it is not possible to take advantage of the inertial forces and create long-term inertial thrust, even if the rotation is synchronized with the shifted natural frequency. The discussion includes extensions into the electromagnetic realm by comparing the mechanical system with its electrical equivalent.
Modeling and simulation of a piezodisc generator under central load
Authors: Wang Shuyun , Kan Junwu , Wang Bin , Yang Zhenyu , Ling Ronghua , Xu Hailong , Cheng Guangming
Published: December 2018

To enhance the energy-generating capability and obtain the optimal structural/material parameters, the deflection function of piezodisc and analytical model of energy generation is established based on the summation method in the theory of plates and shells. The influence of radius/thickness/Young's-modulus ratios of the piezodisc on energy generation was investigated. The research results show that there are different optimal thickness/radius/Young's-modulus ratios for a piezodisc generator under given central force and displacement to obtain maximal electrical energy. To enhance generated energy of a piezodisc under given central force, low Young's modulus ratio is helpful. While, high Young's modulus ratio should be utilized for a piezodisc generator under given central displacement. The Young's modulus radios of the piezodiscs with beryllium-bronze/brass/aluminum substrates are 1.5/1.1/0.94 respectively, and the optimal thickness-ratios/radius-ratios/maximal-energy under central force of 25 N are 0.55/0.43/0.35, 0.64/0.67/0.69, and 2.24/2.63/2.96 × 10 ^{-4} J. Whereas, those under given central displacement of 0.25 mm are 0.4/0.35/0.3, 0.85/0.86/0.87, and 2.7/2.19/1.96 × 10 ^{-4} J, respectively.
Equations for high-frequency vibrations of piezoelectric plates derived from a semi-mixed variational principle and applications in resonators
Authors: Zhang Chunli , Chen Weiqiu , Yang Jiashi
Published: December 2018

We derive two-dimensional equations for high-frequency vibrations of piezoelectric plates from a semi-mixed variational principle with the mechanical displacement vector, the electric potential, and the electric displacement vector as independent fields. This variational formulation allows independent expansions of the three fields into power series of the plate thickness coordinate. Similar to the shear correction factors used in Mindlin's equations for piezoelectric plates to adjust the thickness-shear frequencies predicted by the plate equations slightly so that they become the same as the exact frequencies from the three-dimensional equations, a charge correction factor is conveniently introduced in the plate equations in the present paper so that the inaccuracy of the plate equations in the literature in predicting the charge or current on the electrodes of an electroded plate is corrected. The final equations obtained are convenient and accurate to use for both electroded and unelectroded plates, and for calculating both the voltage and the charge on the electrodes at the plate surfaces in the case of an electroded plate.
Improving the energy conversion process in the switched reluctance motors
Authors: El-Kharashi Eyhab
Published: December 2018

Simply to improve the energy conversion process in the switched reluctance motor the magnetic circuit topology must be modified and the losses must be minimized. The magnetic geometry of switched reluctance machines has been effectively fixed for many years. The paper introduces different new magnetic circuit topologies to improve the energy conversion process in the switched reluctance motor. The switched reluctance motors always operate in the transient mode because of the switching process between the phases consequently the iron losses have a high value in comparison with the rest of the electrical machines due to the switching frequency. From this point of view the magnetic circuit of the switched reluctance motor must be re-shaped by a particular way to minimize the losses. There are many advantages of the presented new designs such as they are quite easy to be built and possess an efficient energy conversion process.
Parametric design for a piezoelectric cantilever carrying oscillators to harvest multi-frequency vibration energy
Authors: Liu Haili , Xu Tianzhu , Huang Zhenyu , Chen Dayue
Published: December 2018

Vibration-based piezoelectric energy harvesters usually work at their resonant frequencies. The resonant frequencies can match, at most, one or two ambient exciting frequencies. In order to freely design multiple operating frequencies to match the given exciting frequencies, several oscillators were attached on a piezoelectric cantilever in this paper, which is named as a multi-mode piezoelectric energy harvester (MPEHer). A distributed-parameter model of the MPEHer was established to predict its output power, and then a lumped-parameter model was derived to determine its operating frequencies. With the lumped-parameter model, the oscillator parameters can be searched for given exciting frequencies. Considering the volume and weight limitation in engineering application, optimizing procedures for the MPEHer were further proposed. Following these procedures, an MPEHer limited by the oscillator-to-cantilever mass ratio of 2.7 was designed for two given exciting frequencies. Experiments show that, under the same input excitation, the average output power of the designed MPEHer is increased by 82% compared with that of a classical configuration, i.e. a piezoelectric cantilever with a tip mass.
Viscous potential flow analysis of electrohydrodynamic Kelvin-Helmholtz instability with heat and mass transfer: Effect of free surface charge
Authors: Awasthi Mukesh Kumar
Published: December 2018

The electrohydrodynamic Kelvin-Helmholtz instability of the interface between two uniform superposed viscous and electrically conducting fluids in the presence of a free surface charge has been studied, when there is heat and mass transfer across the interface. Viscous potential flow theory has been used for the investigation. A dispersion relation has been derived for the linear stability analysis and the stability of the system is analyzed theoretically and numerically. Various graphs with respect to physical parameters, such as electric field, heat transfer coefficients, viscosity of the fluids and permittivity ratio have been drawn and effect of various parameters have been described. It has been observed that free surface charge and electric field both have stabilizing effect while heat transfer destabilizes the system.
FEM analysis of magnetorheological fluid seal of circular cooler and its experimental research
Authors: Zhou Hongliang , Bai Minghua , He Yunhua , Ren Subo
Published: December 2018

Magnetorheological fluid (MRF) exhibits drastic changes in rheological properties adjustable and controllable yield stress under external magnetic field. Based on its specialty, the MRF seal technique is proposed to deal with the air leakage of circular cooler to improve the energy efficiency for the steel industry. MRF is regarded as Bingham fluid with its magnetization vector and magnetic force expressed by mathematical functions. The FEM analysis results show that, under magnetic field, MRF which presents good pressure resistance as a result of its yield stress is in a dynamic equilibrium state in non-magnetic seal groove even with pressure difference, and due to the volume force, it presents unsteady swirl flow obviously at the right-angle edges of the two permanent magnets nearby non-magnetic separator, whereas, due to pressure difference, it shows an obvious flow without magnetic field. In the meantime, according to the experiment, it indicates that the air leakage of circular cooler is solvable effectively with the MRF seal method, and it is also proved that MRF shows controllable yield stress under magnetic field.
3D electrical impedance tomography represented by reconstructed planes in a semispherical electrode array model
Authors: He Wei , Ran Peng , Xu Zheng , Li Bing
Published: December 2018

This paper addresses the augmentation of a conventional plane electrode arrays electrical impedance tomography (EIT) system to form a combined electrode arrays EIT system. This enhances the system performs of providing more accordant information of objects. The system is built up of 65 electrodes, composing of 4 horizontal and 8 axial intercrossing image planes. A phantom experiment has been taken and the measurements been processed by Tikhonov Regularization algorithm and reconstructed by the data obtained from the corresponding model. From comparing the reconstructed volume of anomaly with the target, the results indicate that the described method augments the EIT 3-D rebuilding to a distinguishable level. The qualitative results illustrate the feasibility of this composite approach in exploiting sensitivity in 3-D space with expectable spatial resolution and positioning accuracy. Moreover, this method effectively reduces the amount of computation and demonstrates the practical potential of EIT for clinical inspection and monitoring.
Position control of ultrasonic motor using PID-IMC combined with neural network based on probability
Authors: Mu Shenglin , Tanaka Kanya
Published: December 2018

In this paper, a novel control scheme of PID type internal model control (PID-IMC) using neural network (NN) is proposed for the position control of ultrasonic motor (USM). In the proposed scheme, a new NN controller combined with particle swarm optimization (PSO) based on probability is introduced. The NN controller is employed for tuning the control parameter in PID-IMC for compensating the characteristic changes and non-linearity in USM. On one hand, the application of the proposed method avoids the Jacobian estimation in conventional back-propagation (BP) type NN. On the other hand, the PSO based on probability, originated from tribes-PSO, simplifies the PSO setting by reducing the parameters to be set in USM control. For confirming the effectiveness of the proposed method in position control, a group of experiments have been done on an existent USM servo system and the results are studied in this paper.
Natural characteristics of hard-coating damping plates with magnetic and electric effects
Authors: Han Qingkai , Yang Zhengxin , Wang Boping , Zhang Jie , Qi Fei , Li Xuejun
Published: December 2018

Based on the theory of magneto-electro-elastic (MEE) multilayered plate and by using the state-vector and propagator matrix approach, the natural characteristics (i.e. modal analyses) of the hard-coating plates are investigated. The hard-coating plates in this study are composed of a purely elastic substrate and one magneto-elastic or electro-elastic coating layer of which the thickness is much smaller compared to the substrate layer. Firstly, every field variable of the hard-coating multilayered plate is written into one of the two state vectors, which are related to each other by the form of matrix-production; Secondly, all the field variables are expanded into the form of infinite trigonometric series, and then the field variables of two adjacent layers are connected by the propagator matrix which is the expression of the unknown natural frequencies; Finally, by applying the boundary conditions at top and bottom surfaces, the natural frequencies can be exactly solved. Numerical examples are provided in the last part, and effect of both coating thickness and coating material properties (with either magnetic or electric effect involved) on the natural frequencies and mode shapes are discussed. The results are also compared with some finite element results.
Implementation of wireless remote controller with the function of tracking inner coil position for implantable active medical devices
Authors: Lee Sunjung , Lee Seung-ha , Park Ilyong
Published: December 2018

A popular technique for wireless power transfer and data communication between fully implantable active medical devices and base stations is inductive coupling. A weakness of current technology means that the magnetic coupling coefficient is sharply decreased by variations in the distance and misalignment between two coils. This can result in degradation of communication and efficiency of power transfer between implants and external devices. In this paper, a method to track the coil position of the implant device using a 3-axis magnetic sensor module in the wireless remote controller has been proposed for efficient power transfer and robust data communication. The magnetic sensor module is implemented for obtaining the magnetic flux vector of the magnet in the middle of the inner coil. Based on the obtained magnetic flux vector, the pseudo-distance vector between the inner coil and the outer coil can be calculated and the position of the inner coil can be tracked. From experiments to evaluate the performance of the implemented remote controller's ability to find the inner coil position, we found that our remote controller could track the position of the inner coil of the implant device with the averaged error range of 3.73 mm and increase to a maximum of about 30% above the minimal power requirement for charging a battery of the mock-up implant device. It is expected that the implemented remote controller can be used for implantable active medical devices such as fully implantable middle ear hearing devices.
Improvement in radiation losses of spur line resonators based LPF on an EBG substrate
Authors: Mukherjee Biswajeet , Tiwari Shashank , Samariya Ajay Lal
Published: December 2018

Filters have always remained a field of immense interest in the high frequency domain. Emerging applications such as wireless communications continue to challenge RF/microwave filters with ever more stringent requirements-high performance, smaller size, lightweight, and lower cost. In this paper we propose and investigate the application of Electromagnetic Bandgap (EBG) structures for improving the performance of a stub type 5 pole Low Pass Filter with spur line resonators. Whereas the spur line resonators, improve the roll off factor significantly from −22.666 dB/GHz to−38.0893 dB/GHz, the effect of the EBG is evident in reducing the radiation losses of the spur line resonators and getting almost the same return loss and roll off factor.
Investigation of a Hemispherical Dielectric Resonator Antenna for enhanced bandwidth of operation
Authors: Mukherjee Biswajeet , Raj Ankit
Published: December 2018

Due to small size, ease of fabrication; high radiation efficiency, increased bandwidth and low production cost Dielectric Resonator Antennas(DRAs) are very promising for application in wireless communications. Further, the ability to withstand high temperature variations gives it a very wide application range. In our research, a Hemispherical DRA has been investigated whose bandwidth has been enhanced from 11.4% to 16.44% under different structural geometries. It was also found that in some cases there was an improvement of Gain and Bandwidth along with a lower return loss to mark a sharp resonance peak. The results were verified using the S-parameter analysis, Impedance Bandwidth calculation and VSWR at the source port with CST and HFSS solvers.
Electromagnetic field diffraction of a paraboloidal mirror under oblique incidence
Authors: Ghaffar A. , Shoaib M. , Mehmood N. , Naz M.Y. , Azam M. , Naqvi Q.A.
Published: December 2018

Asymptotic ray theory (ART) or Geometrical optics approximation shows singularity in the focal region of focusing systems. Maslov's method is a technique which overcomes the defect of asymptotic ray theory (ART). In this research work, electromagnetic field expressions for a paraboloidal mirror are derived in which incident electromagnetic field is considered to be oblique. In this work polarization of the incidence wave are studied under two cases, when the field is parallel and perpendicular to the assumed meridional plane of incidence. The procedure used to calculate the electromagnetic field in the focal region of paraboloidal mirror is Maslov's method. The numerical integration is performed for the integrals obtained by this technique in order to get information about intensity of field in focal region.
Monostatic scattering from two-dimensional two-layer rough surfaces using hybrid 3DMLUV-ACA method
Authors: Li Chao , He Si-Yuan , Yang Jiong , Zhang Zhe , Xiao Bo-Xun , Zhu Guo-Qiang
Published: December 2018

The electromagnetic scattering from two-dimensional two-layer dielectric random rough surfaces is analyzed in this work based on Monte Carlo(MC) simulations. The random rough surface is characterized with Gaussian statistics for surface correlation length and for surface root mean square(RMS) height. The Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) surface integral equation is adopted and implemented. A rigorous three-dimensional(3-D) multilevel UV method combined with adaptive cross approximation (ACA) is proposed to solve for the unknown electric and magnetic surface currents. By calculating monostaitc statistical radar cross section (RCS) of the layered structure, the influence of the rough surface RMS height, the correlation length, the medium permittivity and the layer thickness on the scattering characteristic is investigated.
Study on the homogeneity of deformation under electromagnetic expansion of metal tube
Authors: Li Fen-Qiang , Fang Yang , Zhu Ying , Mo Jian-Hua , Li Jian-Jun
Published: December 2018

In this paper, a 3D numerical simulation method was put forward by coupling magnetic-structural fields, and its reliability was verified through comparing with the experimental data offered by Suzuki. According to the characteristics of electromagnetic expansion of metal tube, this simulation method was used to analyze the uniformity of tube expansion when the length of tube was less than that of the coil. Meanwhile, a curve of homogeneity of electromagnetic tube expansion with different aspect ratios (ratio of length to diameter) of tube was given based on the criterion of uniformity on deformation at the condition of specific parameters presented in this paper. By analyzing the mechanical characteristics of tube expansion, a length range of tube was found where the tube deformed uniformly. The results derived from this paper provided a good guidance for optimization design of electromagnetic ring expansion experiments which will be conducted on and this could ultimately promote the application of electromagnetic forming.