bluuebunny/crossref_metadata_2025 huggingface dataset:
Ser professora negra no ensino superior: vivência e experiências
Authors: Silva Marisleila Julia , Mota de Castro Raimundo Márcio
Published: December 2018

A pesquisa apresenta algumas considerações sobre os princípios democráticos e igualitários prescritos em lei em relação à diversidade racial negra. O recorte que buscamos investigar está centrado nas ações afirmativas implementadas a partir do início deste século e que, apesar das inúmeras críticas, representam um avanço social e político no cenário nacional marcado por um histórico de exclusão em relação à população negra. Os estudos indicam que a garantia dos direitos conquistados ainda se constitui um grande desafio a ser vencido e a educação tem papel fundamental no sentido de colocar em prática atitudes concretas de inclusão e de valorização das diferentes culturas. No viés desse debate, inúmeras temáticas são suscitadas, possibilitando a compreensão da diversidade como instrumento para construção de uma sociedade mais justa e solidária. Por meio da narrativa (auto)biográfica de uma professora negra, docente do ensino superior, inferimos reflexões sobre questões tangentes à diversidade racial negra, na intenção de responder ao questionamento: que sentidos e implicações de formação e relações socioculturais emergem nas narrativas constituídas por professores e professoras negros/as no campo educacional? Esta pesquisa é de abordagem qualitativa, exploratória e bibliográfica, sustentada pelo aporte teórico de Santos (2006); Gomes (2001, 2005, 2007); Munanga (2007, 2008); Cavalleiro (2001) entre outros.
Douleurs chroniques après mise en place d’une prothèse de genou : étude rétrospective observationnelle au CETD de Berck-sur-Mer
Authors: Veys B. , Dequidt C. , Boisselier C. , Desenclos C , Delecourt C. , Grosbety H. , Van Cleef J. , Vertrez F. , Bouillant S. , Cazenave A.
Published: December 2018

Introduction : L’objectif principal était d’évaluer l’efficacité des traitements des douleurs neuropathiques persistantes après mise en place d’une prothèse du genou (DNPG) par patch de capsaïcine et les techniques de neurostimulation électrique, afin de proposer une prise en charge optimale.

Méthodes : Une étude observationnelle, rétrospective, a été réalisée de janvier 2014 à décembre 2015 auprès des patients présentant des gonalgies persistantes après prothèse du genou, hospitalisés au sein du CETD de Berck-sur-Mer. Les patients ont été soumis à une enquête diagnostique pluridisciplinaire et une évaluation multidimensionnelle pluriprofessionnelle. L’efficacité des techniques de neurostimulation électrique et du traitement topique par capsaïcine a été étudiée à partir des données des dossiers médicaux.

Résultats : Cent patients ont été inclus. Douze patients souffraient de douleurs nociceptives, 20 de douleurs neuropathiques pures (DNP) et 68 patients d’un syndrome douloureux régional complexe (SDRC). La moyenne d’âge était de 63,5 ans, le ratio homme/femme de 35/65. Vingt-cinq pour cent des gonalgies rattachées à un SDRC apparaissent durant le deuxième mois postopératoire. La neurostimulation transcutanée (85 patients) semble plus efficace en cas de DNP (78 % de répondeurs à 30 %) qu’en cas de SDRC (52 % de répondeurs à 30 %) [p = 0,127], reste efficace quel que soit le délai de prise en charge. L’application du patch de capsaïcine ne soulage qu’environ un patient sur deux que ce soit en cas de DNP (55 % de répondeurs à 30 %) qu’en cas de SDRC (58 % de répondeurs à 30 %), avec une efficacité plus spectaculaire en cas de SDRC. Plus l’application du patch est précoce, plus le soulagement est important (p = 0,036). Par ailleurs, cette étude permet de confirmer que ce traitement topique agit sur toutes les composantes des douleurs neuropathiques, à la fois les symptômes d’allodynie et les douleurs spontanées. La stimulation médullaire chronique reste une alternative efficace vis-à-vis des douleurs neuropathiques réfractaires (quatre patients). L’efficacité de notre prise en charge globale, mesurée à l’aide du questionnaire d’impression globale de changement à trois mois, constate une amélioration significative chez 70 % des patients présentant une DNP et 80 % des patients présentant un SDRC.

Conclusion : Notre étude rétrospective confirme l’efficacité des techniques de neurostimulation électrique et du traitement topique à longue durée d’action par patch de capsaïcine dans le traitement des douleurs neuropathiques persistantes après mise en place d’une prothèse du genou. Un dépistage précoce des DNPG (par une surveillance systématique) peut permettre une prise en charge plus rapide et donc plus efficiente.
Utjecaj hladne maceracije na kakvoću vina Grk
Authors: Jagatić Korenika Ana-Marija , Batisitć Ivan , Jeromel Ana
Published: December 2018

Hladna maceracija se sve više nameće kao jedan od uobičajenijih tehnoloških postupaka u proizvodnji bijelih vina čime se utječe na kompleksnost arome i punoću okusa vina. Područje uzgoja autohtone sorte ´Grk´ (Vitis vinifera L.) usko je vezano uz otok Korčulu pri čemu je najpoznatiji vinogradarski položaj u Lumbardi. Dosadašnja tehnologija proizvodnje bijelih vina na tom području bila je vezana isključivo uz postupak brze prerade ili uz tradicionalnu maceraciju u nekontroliranim uvjetima. Cilj ovoga rada je primjenom kontrolirane hladne maceracije i različitih selekcioniranih sojeva kvasaca definirati osnovna fizikalno-kemijska svojstva, aromatski profil te senzorna svojstva vina Grk. U istraživanju je korišteno grožđe sorte ´Grk´, berbe 2014. godine te komercijalni sojevi kvasaca Lalvin EC 1118 i Lalvin QA23. Neposredno nakon procesa runjenja i muljanja ohlađenoga grožđa, dobiveni masulj maceriran je na temperaturi od 10 °C u trajanju od 6 sati. Nakon procesa taloženja, moštovi su inokulirani selekcioniranim kvascima te je provedena alkoholna fermentacija u kontroliranim uvjetima. U dobivenim vinima je provedena osnovna fizikalno-kemijska analiza prema metodama OIV-a, analiza aromatskih spojeva uz pomoć plinske kromatografije te senzorno ocjenjivanje.
Utjecaj tehnologije fermentacije imobiliziranim kvascima na prisutnost biogenih amina u pjenušcu
Authors: Miličević Borislav , Babić Jurislav , Ačkar Đurđica , Jozinović Antun , Previšić Vlado , Miličević Radoslav , Šubarić Drago
Published: December 2018

Novi trendovi na području sigurnosti hrane povećali su fokus na elemente i spojeve u tragovima koji mogu utjecati na ljudsko zdravlje, u koje se ubrajaju i biogeni amini. Biogeni amini su biološki aktivni dušični spojevi male molekulske mase. U vinu mogu nastati iz prekursora, djelovanjem mikroorganizama u bilo kojoj fazi proizvodnje. Cilj ovoga rada bio je ispitati utjecaj fermentacije imobiliziranim kvascima na sadržaj biogenih amina u pjenušcu. Kvantitativno određivanje provedeno je pomoću RP-HPLC (Reversed Phase High Performance Liquid Chromatography) te je utvrđeno da je pjenušac proizveden pomoću imobiliziranih kvasaca sadržavao niži udio biogenih amina (5,41 mgL-1 u odnosu na 7,24 mgL-1 u klasično proizvedenom).
Percepcije i stavovi građana o primjeni i održavanju cvjetnih vrsta na terasama i balkonima Knina
Authors: Dorbić Boris , Filipović Glorija , Friganović Emilija , Temim Elma , Pamuković Anita , Hadžiabulić Alisa , Davitkovska Margarita
Published: December 2018

Oduvijek je poznato kako se uređenju terasa i balkona poklanjala velika pažnja, ali prije svega i znanje o pojedinim vrstama cvijeća, kako ih uzgajati, njegovati i održavati. Njega o cvjetnim lončanicama ovisi o mjestu na kojem se uzgajaju, supstratu te vremenskim uvjetima koji djeluju na njihov rast i razvoj. Biljke koje se uzgajaju na balkonima i terasama najčešće dolaze iz Sredozemlja, tropskih ili suptropskih područja. Grad Knin ima submediteransku klimu, koju karakteriziraju duge zime s velikom količinom kiše te vruća ljeta s malo oborina. Cilj rada je bio utvrditi percepciju nabave, uporabe, primjene i održavanja cvjetnih vrsta na balkonima i terasama grada Knina metodom anketnog istraživanja. Istraživanje je provedeno tijekom mjeseca lipnja 2016. godine. Na temelju anketnog istraživanja provedenog na građanima Knina i okolice utvrđeni su njihovi stavovi i mišljenja o nabavi, uporabi i primjeni cvjetnih lončanica na terasama i balkonima. Građani su ocjenom vrlo dobar (4,37) među ostalim ocijenili važnost dekoriranja balkona ili terasa cvjetnim lončanicama kako bi se unaprijedila ukupna estetska slika grada. 47,5 % građana grada Knina navodi kako za ukrašavanje svojih balkona i terasa koristi kombinaciju trajnica, jedno i dvogodišnjih cvjetnih vrsta te lukovičastih vrsta. Boravak na balkonu ili terasi ukrašenim cvjetnim lončanicama kao zamjenu za boravak u prirodi ocijenili su ocjenom 4,12. Najmanje preferiraju uporabu cvjetnih lončanica u visećim žardinjerama (3,42).
Onečišćenje okoliša pesticidima kod primjene prskalica i orošivača i mogućnosti njegova smanjenja
Authors: Poje Tomaž
Published: December 2018

Poljoprivreda kao djelatnost svrstava se prvenstveno u difuzne (raspršene) izvore onečišćenja okoliša. Takvi izvori onečišćenja teže se nadziru u odnosu na točkaste, koji su vezani za ispuštanje otpadnih voda iz gradova i stambenih naselja. Međutim, poljoprivreda se može pojaviti istovremeno i kao točkasti (koncentrirani) izvor onečišćenja. Kod pripreme škropiva i kod vanjskog pranja strojeva za zaštitu bilja može doći do onečišćenja okoliša pesticidima. Zato treba pripremu škropiva i vanjsko pranje strojeva nakon aplikacije pesticida izvoditi na betonskoj podlozi, gdje se otpadna voda od pranja i moguća odlijevanja sredstava skuplja i dalje obrađuje jednim od biopurifikacijskih sustava. U Sloveniji su postavljena dva sustava za pročišćavanje otpadnih voda kontaminiranih pesticidima. Jedan radi na principu otparavanja vode, a drugi na način razgradnje pesticida pomoću mikroorganizama u supstratu.
Zastupljenost ekološkog voća na odabranim prodajnim mjestima u Gradu Zagrebu
Authors: Batelja Lodeta Kristina , Megla Petra , Kereša Snježana , Bošnjak Mihovilović Anita , Mesić Željka , Očić Vesna , Gugić Josip
Published: December 2018

U Hrvatskoj se posljednjih godina povećala ukupna površina pod ekološkom poljoprivredom kao i površine pod ekološkim voćnjacima. Analizom ponude na izravnim i neizravnim prodajnim kanalima u Gradu Zagrebu tijekom 2017. godine utvrđeno je da je domaće ekološko voće prvenstveno zastupljeno u izravnim kanalima (tržnice). U neizravnim kanalima (hipermarketi i specijalizirane prodavaonice) ponuda voća je veća, no ono je prvenstveno iz zemalja EU. Ponuda domaće proizvedenog ekološkog voća na području Grada Zagreba nije zadovoljavajuća, ali budući da se radi o višegodišnjim kulturama, možemo očekivati povećanje ponude, homogeniju kvalitetu i dostatne količine te prisutnost i na drugim prodajnim kanalima.
Pregled simptoma, epidemiologije i mjera za sprječavanje širenja zlatne žutice vinove loze u nezaražena područja
Authors: Grozić Kristina , Bubola Marijan , Poljuha Danijela
Published: December 2018

Zbog potencijalno visokih šteta koje može uzrokovati, zlatna žutica se smatra jednom od najštetnijih bolesti vinove loze u Europi, gdje je indeksirana na A2 EPPO listi karantenskih organizama (Direktiva 2000/29/EC). Vektor koji epidemijski prenosi zlatnu žuticu s trsa na trs je američki cvrčak. Primarne štete uzrokovane zlatnom žuticom su znatno smanjenje prinosa i propadanje zaraženih trsova, a ukoliko se ne provode potrebne mjere suzbijanja, bolest se može epidemijski širiti te u roku od svega nekoliko godina vinograd može postati u potpunosti zaražen i neproduktivan. U slučaju sumnje na zarazu, potrebno je provjeriti javljaju li se na trsu najmanje tri različita simptoma koja su tipična za zlatnu žuticu, a to su promjena boje lista, izostanak odrvenjavanja mladica i sušenje bobica ili nekroza grozdova. Navedeni simptomi međutim nisu pouzdani pokazatelji zaraze zlatnom žuticom te se sa sigurnošću ova bolest može potvrditi jedino laboratorijskom analizom. U regijama u kojima zlatna žutica još nije utvrđena, iznimno je važno provoditi temeljito praćenje vinogradarskog područja kako bi se spriječio unos i eventualna pojava epidemijskog širenja zlatne žutice. Neke od ključnih mjera koje treba primijeniti u vinogradarskim regijama prije unosa zlatne žutice uključuju praćenje distribucije i visine populacije američkog cvrčka, uz izostanak primjene mjera suzbijanja vektora ukoliko je njegova populacija niska ili nepoznata. U područjima gdje je vektor zastupljen u visokim populacijama preporuča se primijeniti mjere njegova suzbijanja uz temeljito praćenje svih vinograda (proizvodnih i zapuštenih) kako bi se pravovremeno utvrdila eventualna pojava simptoma zlatne žutice vinove loze. U ovom je radu dan pregled simptoma zlatne žutice, primarnog vektora američkog cvrčka, biljaka domaćina te njihovog međusobnog odnosa, kao i pregled mjera za prevenciju širenja zlatne žutice u nova nezaražena područja.
Siva plijesan vinove loze
Authors: Jelinić Jelena , Ilić Jelena
Published: December 2018

Siva plijesan je jedna od ekonomski najznačajnijih bolesti vinove loze, koja se javlja svake godine u većem ili manjem intenzitetu. Osim na vinovoj lozi javlja se na vrlo velikom broju biljaka. Uzrokuje ju gljivica Botrytis cinerea Pers. koju zbog pojave na velikom broju kultura nazivamo polifagom. Javlja se svake godine te se proizvođačima za njeno suzbijanje preporučuju preventivne mjere kako bi se maksimalno smanjio intenzitet bolesti. Uz te mjere vrše se i obavezna tretiranja fungicidima. Uspješnost borbe protiv ove bolesti ovisi prije svega o vremenskim uvjetima, osjetljivosti sorte vinove loze te o količini zaostalog inokuluma patogene gljive u polju.
Duhanski otpad Bosne i Hercegovine – problem ili vrijedna sirovina
Authors: Banožić Marija , Šubarić Drago , Jokić Stela
Published: December 2018

Duhan se na području Bosne i Hercegovine proizvodi još od prve polovice 17. stoljeća, a sedamdesetih i osamdesetih godina prošlog stoljeća proizvodnja doživljava svoj vrhunac, nakon čega slijedi stagnacija i naglo opadanje proizvodnje. Ipak duhan se na području Bosne i Hercegovine, još uvijek uzgaja kao važna poljoprivredna kultura. Zbog neorganiziranog otkupa kao i nedostatka nadzora od strane države Bosne i Hercegovine nad proizvodnjom duhana, proizvođači svu svoju proizvodnju duhana plasiraju na sivo tržište u obliku poluproizvoda, rezanog duhana, poznatog na ostalim tržištima kao hercegovačka škija, dok na području Posavine postoji organizirani otkup, no niska otkupna cijena, proizvođače stavlja u izuzetno težak položaj. Je li revitalizacija duhana na području Bosne i Hercegovine moguća? Općeprihvaćeno mišljenje je da je revitalizacija nekadašnjeg načina uzgoja duhana zbog promjena preferencija potrošača, tipova cigareta i promjene tehnologije obrade duhana nemoguća. No potrebno je tražiti alternativne načine plasiranja ovih tipova duhana, kao duhana za motanje, te kao autohtonih proizvoda. Jedna od najvažnijih komponenti je i uloga države, s obzirom da duhan podliježe posebnom sustavu trošarina i poreza. U lancu vrijednosti, od poljoprivrednih proizvođača, do prerađivača, važna komponenta je i zbrinjavanje otpada. S obzirom da je duhanski otpad, bogat izvor visokovrijednih komponenti koje su i prikazane u ovom preglednom radu, njegovo iskorištavanje moglo bi dati dodatnu vrijednost i podići nisku otkupnu cijenu duhana, a ujedno riješiti i problem zbrinjavanja ovog opasnog otpada.
Neuronal Exosome-Derived Human Tau is Toxic to Recipient Mouse Neurons in vivo
Authors: Winston Charisse N. , Aulston Brent , Rockenstein Edward M. , Adame Anthony , Prikhodko Olga , Dave Kishan N. , Mishra Priyanka , Rissman Robert A. , Yuan Shauna H.
Published: December 2018

Progressive accumulation of aggregation-prone proteins, amyloid- β (A β) and hyperphosphorylated tau (p-tau), are the defining hallmarks of Alzheimer’s disease (AD). The mechanisms by which A β and p-tau are transmitted throughout the diseased brain are not yet completely understood. Interest in exosome research has grown dramatically over the past few years, specifically due to their potential role as biomarkers for staging of neurodegenerative diseases, including AD. Despite their diagnostic utility, the pathogenic potential of exosomes has yet to be fully elucidated. In this study, we use a series of recombinant tau antibodies to characterize a new model of human tau in vivo. Exosome suspensions derived from neuronally-differentiated, human induced pluripotent stem cells that express the repeat domain of tau P301L and V337M mutations (NiPSCEs) were injected into the wild-type mouse brain and pathological changes were characterized by immunostaining at one- (1 m) and two-month (2 m) post-injection. We found that tau inclusions were present throughout the brain at 2 m post-injection, which were detectable using antibodies raised against full-length tau (K9JA) and misfolded tau (MC1). Furthermore, we found that phosphorylated tau immunoreactivity was elevated 1 m post-injection, which was surprisingly normalized after 2 m. Finally, we observed extensive degeneration of neuronal dendrites in both ipsilateral and contralateral hippocampi in NiPSCE treated mice. In summary, we demonstrate that exosomes are sufficient to cause long-distance propagation of tau pathology and neurodegeneration in vivo. These novel findings support an active role of exosomes in AD pathogenesis.
Robotic cell injection force control based on static PVDF sensor and Fuzzy-PID control method
Authors: Sun Zhiyong , Hao Lina , Chen Wenlin , Li Zhi
Published: December 2018

Cell injection procedure is very essential in the field of molecular biology, and the injection force affects the success rates very much. However, conventional methods of manipulating individual biological cell failed to make use of the injection force information. This article is intended to design a static micro-force sensor with a simple structure which employs the piezoelectric material PVDF (polyvinylidene fluoride) film as its sensing element to detect the micro-force during cells injection and to develop a close-loop control method to regulate the whole fore-tracking system. A Fuzzy-PID and an ordinary PD feedback control method are employed separately in this article to regulate the micro-force tracking system which is used to carry out automatic living-cell injection tests. Experimental results with different control methods are achieved. And the Fuzzy-PID and PVDF sensor based force control method is validated.
Design and development of hinge-type microstirrer for thrombus dissolution
Authors: Morita Minoru , Jiang Zongwei , Yamamoto Kazunori , Suzuki Michiyasu
Published: December 2018

Cerebral strokes occur on account of a thrombus formed in blood vessels, which blocks the blood flow to the brain and induces brain cell necrosis. We require the ability to quickly treat this by dissolving the thrombus with a low risk of brain hemorrhage. In this study, we concentrate on the design of a high-performance microstirrer to dissolve the thrombus. The piezoactuator is selected and discussed because it has both sensing and actuation functions, and has a high power in relation with its size. Further, a new type of microstirrer is designed to generate high-amplitude vibration, and its motion can be easily controlled by adjusting the input signals to the actuators. Several types of microstirrers were manufactured on the basis of the finite-element method (FEM) simulation results, and the effect on the dissolution was experimentally validated.
Fabrication and thermoelectricity of La_{1-x}(Ca, RE)_{x}VO_{3}(⩽ x ⩽ 1) composition-spread films
Authors: Wang Qunjiao , Chang Shouwei
Published: December 2018

La _{1-x} (Ca, RE) _x VO _3 (0⩽ x ⩽ 1) composition-spread films were fabricated successfully by Combinatorial Pulsed Laser Deposition (CPLD). The structures and thermoelectric (TE) properties of the films were evaluated paralelly by Concurrent X-ray Diffraction (CXRD) and Multi-channel Thermoelectric Measurement systems respectively. The CXRD (200) peaks of the composition-spread films changed linearly, which indicated that the composition-spread films formed solid solution in the whole composition range (0 ⩽ x ⩽ 1). The effects of oxygen content and the substitutions of Ca and rare earth (RE: Ce, Nd, Eu) ions on TE properties of LaVO _3 were also analysed respectively. There was little change in the Seebeck coefficients of LaVO _3 films grown at different growth temperatures, while the resistivity decreased with the enhance of the growth temperatures. The largest power factor (0.7 μW/cm K ^2 ) of LaVO _3 film was obtained at 800°C, while the valence of vanadium ion changed from 3+ to 2+ because of the lack of oxygen. With the increase of the content of Ca ^{2+} ions, the valence of vanadium ion changed from 3+ to 4+, which was responsible for the decrease of TE properties in La1-xCaxVO _3 system. The substitution of RE (Ce, Nd, Eu) ions for La ions changed not only Seebeck coefficient but also resistivity, but power factor (α) was not increased obviously. In La1-xCexVO _3 system, La ion took 3+, and Ce ion took 3+ although Ce ^{4+} was stable in theory, which caused the valence of V ion not changed as expected from 3+ to 2+. The reason may be that the size of Ce ^{3+} ion is similar to that of La ^{3+} ion, so Ce takes the valence of 3+ easily in LaVO _3 .
A zero suspension force improvement method of a permanent magnetic suspension device
Authors: Sun Feng , Oka Koichi , Jin Junjie
Published: December 2018

This paper proposes an improvement method of zero suspension force of a permanent magnetic suspension device. The zero suspension force of a magnetic suspension device is indispensable for floating off from the adhere position. Generally, the magnetic suspension system using permanent magnet is difficult to realize the zero suspension force, since the permanent magnet cannot make its attractive force zero. However, the proposed magnetic suspension device that mainly consists of a disk-shape permanent magnet, two"F" shape iron cores, a suspended object, and an actuator, has realized the semi-zero power suspension and semi-zero suspension force. In the magnetic suspension device, since there is magnetic leakage, the suspension force could not be made exact zero. Therefore, in this paper, the zero suspension force performance will be improved using a special shape permanent magnet. Some IEM(Integral Element Method) analysis and experimental measurement have been carried out, and the comparison results indicate that the zero suspension force is decreased above 83 percent comparing with the original device in generally using conditions. Finally, the suspension simulation and experiment results indicate that the suspended object can be levitated robustly.
Buckling of a piezoelectric thin film bonded to compliant substrates
Authors: Zhou Zhi-Dong , Fu Zhi-Peng , Jiang Quan
Published: December 2018

A thin stiff film subjected a compressive force on a compliant substrate can form wrinkles. Buckling stiff piezoelectric thin films hold great applications for micro- and nano-electromechanical systems. The present study focuses on the buckling process of a piezoelectric thin film bonded to a compliant layer, which in turn lies on a rigid support. Nonlinear electromechanical equations for the buckling of a thin piezoelectric plate are employed to model the piezoelectric film poled in the thickness direction. By solving the boundary value problem, the critical buckling condition and the wavelength of the buckles for substrates of various moduli and the thicknesses are obtained and discussed. The effect of piezoelectricity on the critical buckling condition of piezoelectric film is examined. It is found that the piezoelectricity has a stiffening effect, which is not negligible.
Magnetic force analytic model of step conical PMB
Authors: Tian Lulin , Tian Yaqi , Tian Qi , Jia Rong
Published: December 2018

The cost of precision conical permanent magnetic bearings (PMB) is very expensive in the engineering manufacture. Step conical PMB, which consists of by piling up several couples PM rings of different diameters with rectangular cross section, in a conic disposition, characterized by such advantages as low cost and easy manufacture. Based on the magnetic field of planar point magnetic charge, virtual work principle, and superposition theorem, combining two parallel rectangular section permanent magnets (PM) and the structure trait of step conical PMB, the magnetic force analytical model of step conical PMB is established, and the relationship between magnetic force and structure parameters of step conical PMB is analyzed, and the correctness of the magnetic force analytical model is validity by ANSYS simulation, comparisons show that the analytical solution closely matches with the results of the finite element analysis. The results indicate that the magnetic force of step conical PMB is proportional to the magnetic annular average perimeter and the square of residual magnetism induction density, and that the magnetic force increases with an increment in the magnetic annular section size, the axial magnetic force increases with an increment in the axial deflection, the radial magnetic force increases with an increment in the radial deflection. The paper provides technical support for design and structure parameters optimization of step conical PMB.
Efficient solution to the RCS of trihedral corner reflector
Authors: Weng Yin-Kan , Li Song , Yang Jin-Ling , Zhou Hui , Yi Hong , Wang Hong
Published: December 2018

In this paper, a kind of efficient solution to the trihedral corner reflector's (TCR's) radar cross section (RCS) is proposed. Based on the combination of geometrical optics (GO) and Gordan surface integral method, TCR's RCS was computed and was compared with the results from computational electromagnetics software FEKO. Good agreement and significant speedup achieved show that the method mentioned in this paper is capable of practical rapid simulation and design, especially suitable for electrically large plate structure.
Dynamic response of rails due to armature movement for electromagnetic railguns
Authors: Jin Longwen , Lei Bin , Li Zhiyuan , Zhang Qian
Published: December 2018

An analytical model is proposed to investigate the dynamic behavior of rail under the effect of both the rail repulsive force and the armature contact force. The rail is modeled as a Bernoulli – Euler beam resting on a continuous elastic foundation with simply support at both ends of the rail. Numerical simulations are carried out using the analytical model at below, near and above the critical velocities respectively. The results show that the dynamic response of the rail under the effect of both the repulsive force and contact force is more intensive and complicated than the case in which only the repulsive force acted. The additional oscillations caused by the contact force may increase the possibility of electrical contact failure between the armature and the rails. For more detailed analysis, the analytical model is needed to take into account the varying elastic stiffness and damping effect of practical railgun structure.
Investigation of the sensing properties of a localized surface plasmon nanocavity
Authors: Silva Anderson O. , Cardoso Markos P. , Giraldi Maria T.M.R. , Costa João C.W.A.
Published: December 2018

Surface plasmon-polariton excitations are electromagnetic modes responsible for a huge field confinement at the interface between a conductor and a dielectric. These modes mitigate light scattering even below the diffraction limit, which allows the reduction in size of several kinds of electromagnetic devices such as waveguides, resonators and sensors. Within this framework, we apply the FEM-RBCI formulation to investigate the response at the optical spectrum of a nanocavity filled with silver nanodisks. Computational simulations show that the coupling between localized surface plasmon modes excited at the periphery of the nanodisks yields a high sensitivity degree in an ultra-compact area. Such sensitivity is nearly constant and covers a wide range of refraction indexes of the surrounding medium. Furthermore, it is not required any external phase matching technique to achieve surface plasmon resonance. These characteristics demonstrates the great potential of the structure to improve optical sensing applications.
Innovative servo gap-retainer design by applying electromagnetic attraction force
Authors: Aw Hong-Seng , Chiang Chao-Wen , Tsai Nan-Chyuan
Published: December 2018

A TDOF (Two Degrees of Freedom) Servo Gap-Retained Mechanism (SGRM) is proposed and verified by experiments in this work. It mainly consists of a flywheel and an Intelligent Posture Tracking System (IPTS). The flywheel, driven by an induction motor for spinning, is regarded as the tracking objective of the IPTS. The IPTS is mainly composed by an intelligent disc and the Hybrid Magnetic Actuators (HMAs). The posture of the intelligent disc is controlled by the magnetic forces induced by the HMAs to retain a constant gap with respect to the eccentric flywheel which spins, tilts and wobbles. Since the HMA is highly nonlinear, a Feedback-Linearized Sliding Mode Control (FLSMC) is synthesized to account for system parameter nonlinearities or unmodeled dynamics. The dynamics of the flywheel and the IPTS are theoretically investigated and analyzed. In fact, the proposed SGRM is a part of an entire flywheel cell. That is, once the MGU (Motor/Generator Unit) in flywheel cell operates at idle mode, the shaft of flywheel will be separated apart from MGU in order to avoid the energy loss of the flywheel by the back EMF induced by the magnetic field of MGU. On the other hand, the shaft of flywheel and MGU still need to maintain synchronous power transmission even at idle mode so that a non-contact clutch is equipped. Generally speaking, the role of SGRM in a flywheel cell is to ensure the centerline of the flywheel properly aligned with the non-contact clutch. At last, intensive computer and experimental simulations are undertaken to verify the feasibility of the proposed SGRM and FLSMC. It is evidently showed that the proposed SGRM under FLSMC exhibits superior transient response and servo capability upon constant gap retained. The steady-state tracking errors are about 5% with respect to the amplitudes of the reference trajectories in two radial directions (i.e., X-axis and Y-axis).
Influence of slot wedge material on permanent magnet losses in a traction motor with tooth coil windings
Authors: Lindh Pia , Vaimann Toomas , Kallaste Ants , Pyrhönen Juha , Vinnikov Dmitri , Naumanen Ville
Published: December 2018

Permanent magnet (PM) machines with tooth coil windings are designed and analyzed. We study how the slot wedge material affects the behavior of PM losses when using tooth coil windings, which generate a significant air gap flux density harmonic content. The losses and cogging torques of a surface permanent magnet rotor and an interior permanent magnet rotor are compared in no-load and load situations. A finite element analysis applying Cedrat's Flux2D is made. Motors of this size can have high permanent magnet eddy current losses, and therefore, segmented magnets are often preferred even though interior magnets and semi-magnetic wedge material are used. The study shows that tooth coil windings may benefit from using semi magnetic material as a wedge material as it decreases the stator iron losses and, especially, losses in the permanent magnets.
Electromagnetic reflection of conductive plane covered with double inhomogeneous plasma slabs
Authors: Yuan Zhong-Cai , Shi Jia-Ming
Published: December 2018

This paper presents numerical results in the form of graphs of the power reflection coefficients for electromagnetic signals normally incident upon a conductive plane covered with two layers of inhomogeneous plasma slabs. The plasma electron density varies only in the direction perpendicular to the plane. Parameters considered in the computation cover a relatively wide range and the functional dependence of the power reflection coefficients on these parameters is studied. The results indicate that in a rather broad frequency range, the electromagnetic attenuations by the double slabs obviously excel the sum of attenuations resulted from two plasma layers when each layer exits respectively. The structure presented is easy to set up, which is instructive for plasma stealth.
A sensitivity study for microwave breast cancer detection using the Contrast-Source Integral Equation and realistic anthropomorphic numerical 3-D phantoms
Authors: Angiulli G. , De Carlo D. , Isernia T.
Published: December 2018

In this paper, a sensitivity study aimed to evaluate how the field scattered by a malignant tumor is influenced by the operation frequency f_o of the microwave tomographic diagnostic system, and by the permittivity {ϵ}_f of the matching fluid, is presented. The study has been carried out exploiting accurate anthropomorphic numerical breast phantoms in conjunction with the Contrast Source Integral Equation. Numerical results provide useful insights towards an optimal choice of these parameters able to enhance the cancer's detectability.
Dual-band patch antenna with complementary split ring resonators loaded modified ground plane
Authors: Raval Falguni , Kosta Y.P. , Joshi Harshita
Published: December 2018

In this paper, dual-band microstrip antenna with complementary split ring resonator is presented. The designs are based on the metamaterial property of the complementary split ring resonator. A simple dual-band antenna can be realized by etching single CSRR in the ground plane of a conventional patch antenna. The proposed antenna shows good performances at both resonant frequencies. The CSRR in the ground plane makes a major contribution to the first operating band, but it has a minor effect on the second operating band. The simulation results are analyzed and compared with the measured results, which shows that there is a good agreement between them.
A thickness measuring strategy for coating in hemispherical steel shells with EC-laser combined sensors
Authors: Zhang Dongli , Wu Meixian , Wang Zhaoba , Chen Zhenmao
Published: December 2018

In order to make an effective on-line thickness measurement of thick coating in hemispherical steel shells, a strategy using combined laser and eddy current (EC) sensors based on displacement differential method was proposed. To enhance the measuring precision, an EC displacement sensor with large test range was adopted and the effect of shell curvature on its output was reduced by applying the polynomial curve fitting. Its feasibility was verified by experimental results.
Clarification of the rational solution obtained from game theory in multipurposed optimisation problem
Authors: Miyamoto Tomoyuki , Matsutomo Shinya , Terauchi Naoya , Noguchi So , Igarashi Hajime
Published: December 2018

Usually, multiple objectives have to be considered when an electromagnetic apparatus is optimally designed. In such a multipurposed optimal design problem many solutions exist and are termed Pareto optimum. Hence, we have previously proposed a multipurposed optimal design method based on a game theory. The proposed method can choose one rational solution from Pareto optima. It is, however, unconfirmed what the signification of the chosen rational solution is. Therefore, the signification is investigated by calculating the weight parameters of a weighted summed objective function.
Multi-physics design rules using lumped models for a permanent magnet synchronous machine
Authors: Bracikowski Nicolas , Rossi Mathieu , Hecquet Michel , Gillon Fréderic
Published: December 2018

Modeling the dynamic behavior of electrical machines involves several fields of physics, such as electromagnetics, electronics, mechanics, thermodynamics and acoustics. Multi-physics lumped models are applied to an inverter-fed permanent magnet synchronous machine. These models are coupled and fully parameterized to optimize the machine for traction applications. A particle swarm optimization algorithm is used to obtain general tendencies and different design rules. The objective is to provide a decision-making tool using lumped models to design permanent magnet synchronous motors. In this paper, we focus on electromagnetic noise, and average and ripple electromagnetic torque. The magnetic model, a permeance network, provides a good compromise between accuracy and computing time.
Boussinesq contact of transversely isotropic piezoelectric materials
Authors: Yang Fuqian
Published: December 2018

The contact behavior between a transversely isotropic piezoelectric material and a rigid-conducting punch of flat-end was analyzed under the condition that there is no biased-electric potential applied to the punch. Two limiting cases were studied; one was for semi-infinite piezoelectric materials and the other for piezoelectric films with contact radius much larger than the film thickness. Analytical relationships were derived between the indentation load and the indentation depth and between the indentation-induced potential and the indentation depth. Both the indentation load and the indentation-induced potential are proportional to the indentation depth. For the adhesive contact, the pull-off force is proportional to the 3/2 power of the punch radius for semi-infinite piezoelectric materials and to the square of the punch radius for piezoelectric films. The piezoelectric charge coefficient determined from the contact deformation of a piezoelectric film with contact radius much larger than the film thickness is only dependent on dielectric constant and piezoelectric constant.
Thermoelectric coupling model for asphalt mixtures based on microwave heating
Authors: Sun Tongsheng
Published: December 2018

In order to improve recycling quality of asphalt mixtures based on microwave heating, thermoelectric coupling theory is researched. Heat conduction equation is built according to Fourier's Law. Series model, parallel model and Maxwell model are studied to solve thermal conductivity of asphalt mixtures. Radiation field model of pyramidal horn antenna is set up and mean value of electric field intensity is measured by experiment. Thermoelectric coupling model is built on the basis of dielectric property of asphalt mixtures. Numerical simulation is performed for the model. It is found that influence of asphalt-aggregate ratio on temperature field is not distinct. Average temperature of asphalt mixtures is related to microwave power and increases with microwave power linearly. The asphalt mixtures using diorite as aggregate have a strongest adsorption capability to energy. The result can simulate hot in-place regeneration process, and has important significance to improve regeneration quality of asphalt mixtures.
Design and development of a slot-less permanent magnet linear motor using permeance analysis method for spray application
Authors: Parvez Iqbal A.K.M. , Aris Ishak , Norhisam M.
Published: December 2018

Mostly in industrial spray applications pneumatic systems are utilized for operating the automatic spray gun. Linear motor can be one of the alternatives for triggering the spray gun instead of pneumatic systems due to its accuracy in valve positioning according to the required flow rate. From this point of view a tubular linear permanent magnet motor has been designed using Permeance Analysis Method (PAM) and developed. Three permeance models have been developed for PAM analysis. Among these three models, only one model is selected as a PAM model which can be produced the required amount of thrust for triggering the spray gun. After selecting the PAM thrust model, the size of the motor has been optimized by analyzing the effect of thrust constant, electrical and mechanical time constant. Finally based on the optimized data, the motor has been fabricated and tested that shows the good argument with the analysis result.
Effects on reflected and transmitted powers of planar stratified structures involving chiral nihility metamaterials
Authors: Shah Nayyar Abbas , Ahmad Faiz , Syed Aqeel A. , Naqvi Qaisar A.
Published: December 2018

Behavior of different planar multilayer periodic structures due to plane wave excitation has been studied using the transfer matrix method. Multilayer structure is composed of odd number of slabs and the layers at odd locations have same characteristics and layers at even locations have same characteristics. For each structure, layers at odd locations are of chiral nihility metamaterial whereas three different cases are considered for layers at even locations, i.e., dielectric, chiral and chiral nihility. Effects of polarization rotation due to the optical activity of material's chirality is studied with respect angle of incidence and frequency in THz region. Chiral nihility adds property of transparency to the structure for normal incidence. Chiral nihility-chiral nihility structure for normal incidence yields transparency whereas same structure for oblique incidence yields total rejection at higher frequencies.
The signal characteristics of light flash generated by hypervelocity impact natural dolomite plate
Authors: Tang Enling , Xu Hongjie , Wang Meng , Zhang Qingming , Li Zhiqiu , Xiang Shenghai , Yang Minghai
Published: December 2018

To investigate light flash produced during hypervelocity impact in the laboratory, we have conducted a series of experiments on a two-stage light gas gun at different impact velocities and the same impact angle. Light flash were acquired through optical fiber pyrometer measurement system during the whole physical process in hypervelocity impact, Experimental results showed that the maximum light flash intensity decreases with impact velocity increasing, and maximum light flash intensity should exist a critical impact velocity for polycarbonate projectile impacting natural dolomite plate, which may be between 2.52 km/s and 4.21 km/s at the wavelength of 550 nm–700 nm. In addition, the light flash intensity peak value was 0.4 ∼ 0.5 mW.cm ^{-2} .nm ^{-1} in the experimental conditions in the paper.
Design, fabrication and performances of MEMS piezoelectric energy harvester
Authors: Li Ping , Gao Shiqiao , Cai Huatong , Cui Yan
Published: December 2018

MEMS piezoelectric energy harvester is optimally designed and fabricated, and its vibration characteristics, output voltage, power, power spectral density (SD) and frequency response function under harmonic and random excitation is studied by theory analysis, simulation and experimental test. For the designed MEMS piezoelectric energy harvester, the accurate solutions and expressions of amplitude, voltage, power and power spectral density are derived. Then, vibration characteristic, voltage, power and power SD with different load resistance, sinusoidal acceleration and random acceleration SD are simulated and tested; moreover, frequency response function of MEMS piezoelectric energy harvester is obtained by experimental test, and the results are consistent with theoretical model. When sinusoidal acceleration is 0.6 g, the maximal amplitude of mass is 116 μm and the power density is 0.1 mW/cm ^{3} . By testing results, output voltage of piezoelectric energy harvester is proportional to the amplitude, and the amplitude at optimal load is smaller than of at open circuit because of the feedback effect of load resistance. In addition, output power SD linearly increases with acceleration SD increasing. When acceleration SD is 5× 10 ^{-4} (m/s ^{2} ) ^{2} /Hz, power SD is 1.24 μW ^{2} /Hz.
Viscous potential flow analysis of electrohydrodynamic capillary instability with heat and mass transfer: Effect of free surface charge
Authors: Tiwari D.K. , Awasthi M.K. , Agrawal G.S.
Published: December 2018

We study the electrohydrodynamic capillary instability of the interface between two uniform superposed viscous and electrically conducting fluids in the presence of a free surface charge, when there is heat and mass transfer across the interface. The fluids are subjected to the uniform electric field in the axial direction and the viscous potential flow theory is used for the investigation. A quadratic dispersion relation that accounts for the growth of disturbance waves is derived for the linear stability analysis and the stability of the system is analyzed theoretically and numerically. The stability criterion is given in terms of the critical value of applied electric field as well as critical wave number. Various graphs with respect to physical parameters such as electric field, heat transfer coefficients, conductivity and permittivity ratio are drawn and effect of various parameters is described. It is observed that free surface charge and electric field both have stabilizing effect on the stability of the system.
Electromechanical coupled nonlinear free vibration of rails for electromagnetic railguns
Authors: Xu Lizhong , Zheng Fengjie , Peng Lingchao
Published: December 2018

The railgun system is an electromechanical coupled nonlinear system. Here, considering the electromagnetic force nonlinearity of the rail, the electromechanical coupled nonlinear dynamic equations for the rail are proposed. Using these equations, the nonlinear vibrating frequencies of the railgun system and their changes along with the system parameters are investigated. The amplitude frequency characteristics of the rail are discussed. The results show that the electromagnetic nonlinearity should be considered for a small stiffness of the elastic foundation, small distance between the two rails, and a large rail current. The results can be used for dynamic performance design of the railgun system.
Analysis of slot loaded compact patch antennas for dualband operation
Authors: Singh Ashish , Ansari J.A. , Kamakshi Dr. , Aneesh Mohd. , Sayeed Saiyed Salim
Published: December 2018

In this article, analysis of slot loaded compact rectangular patch antennas have been presented theoretically using circuit theory concept. The theoretical investigations of L-strip fed slot loaded compact rectangular microstrip patch antenna parameters such as return loss, VSWR, radiation pattern have been calculated. It is found that antenna resonates at 2.95 GHz and 6.01 GHz for lower and upper resonance frequencies respectively. The bandwidth of the L-strip fed slot loaded compact rectangular microstrip patch antenna at lower resonance frequency is 1.16% (simulated) and 10.16%(theoretical) whereas at upper resonance frequency, it is 1.5% (simulated) and 2.51% (theoretical). The characteristics of the L-strip fed slot loaded compact rectangular microstrip patch antennas is compared with other rectangular patch antennas. Circuit diagram of this antenna is proposed, fabricated and simulated using AWR circuit simulator. The theoretical results are compared with IE3D and AWR simulation results along with measured results and they are in close agreement.
Equivalent MFL model of pipelines for 3-D defect reconstruction using simulated annealing inversion procedure
Authors: Chen Junjie , Huang Songling , Zhao Wei
Published: December 2018

In this paper, we propose an equivalent forward model of magnetic flux leakage (MFL) inspection in pipelines to reduce the computation effort to predict MFL signals. Then an iterative simulated annealing inversion procedure is developed to reconstruct the three-dimensional (3-D) defect profile from MFL signals. Experiments results, based on both simulated and measured MFL signals, demonstrate that the proposed inversion procedure using the equivalent forward model has high performance in terms of execution speed and accuracy.
A novel method transferring the copper rod without contact by axial magnet wheels
Authors: Jung Kwang Suk
Published: December 2018

An axial magnet wheel, in which permanent magnets are arranged circumferentially and polarized periodically, is proposed as a driving method to transfer a conductive rod without mechanical contact in space. The magnet wheel, whose axial plane is laid parallel to the rod, is rotated to generate three axial magnetic forces on the rod. But, the all forces are strongly coupled to each other through the rotational speed of the wheel. Furthermore, the number of degrees of freedom to be controlled in the transfer system, in which the rod is supported by two pairs of magnet wheels actuated by two wheel motors, is more than the number of input variables. To solve the above problem, a novel method in which the transfer control of the rod is converted to a tilt control of the rod is proposed and verified experimentally. And, the force characteristic of the magnet wheel is analyzed for variations of the main geometric parameters to obtain the desired design specifications.