bluuebunny/crossref_metadata_2025 huggingface dataset:
The management of clival chordomas: an Italian multicentric study
Authors: Cavallo Luigi Maria , Mazzatenta Diego , d’Avella Elena , Catapano Domenico , Fontanella Marco Maria , Locatelli Davide , Luglietto Davide , Milani Davide , Solari Domenico , Vindigni Marco , Zenga Francesco , Zona Gianluigi , Cappabianca Paolo
Published: September 2020

OBJECTIVE

In the last 2 decades, the endoscopic endonasal approach in the treatment of clival chordomas has evolved to be a viable strategy to achieve maximal safe resection of this tumor. Here, the authors present a multicentric national study, intending to analyze the evolution of this approach over a 20-year time frame and its contribution in the treatment of clival chordomas.

METHODS

Clival chordoma cases surgically treated between 1999 and 2018 at 10 Italian neurosurgical departments were included in this retrospective study. Clinical, radiological, and surgical findings, adjuvant therapy, and outcomes were evaluated and compared according to classification in the treatment eras from 1999 to 2008 and from 2009 to 2018.

RESULTS

One hundred eighty-two surgical procedures were reviewed, with an increase in case load since 2009. The endoscopic endonasal transclival approach (EETA) was performed in 151 of 182 cases (83.0%) and other approaches were performed in 31 cases (17%). There was an increment in the use of EETA, neuronavigation, and Doppler ultrasound after 2008. The overall postoperative complication rate was 14.3% (26 of 182 cases) consisting of 9 CSF leaks (4.9%), 7 intracranial hemorrhages (3.8%), 5 cases of meningitis (2.7%), and 5 cerebral ischemic injuries (2.7%). Gross-total resection (GTR) was achieved in 93 of 182 cases (51.1%). Extent of resection (EOR) improved in the second era of the study. Signs and/or symptoms at presentation worsened in 27 cases (14.8%), and the Katz Index worsened in 10 cases (5.5%). Previous treatment, dural involvement, EETA, and intraoperative Doppler ultrasound correlated with GTR. Patients received adjuvant proton beam radiation in 115 of 182 cases (63.2%), which was administered more in the latter era. Five-year progression-free survival (PFS) and overall survival (OS) were 62.3% and 73.5%, respectively. GTR, EETA, proton beam therapy, and the chondroid subtype correlated with a better survival rate. The mean follow-up was 62 months.

CONCLUSIONS

Through multicentric data collection, this study encompasses the largest series in the literature of clival chordomas surgically treated through an EETA. An increase in the use of this approach was found among Italian neurosurgical departments together with an improved extent of resection over time. The satisfactory rate of GTR was marked by low surgical morbidity and the preservation of patient quality of life. Surgical outcome was reinforced, in terms of PFS and OS, by the use of proton beam therapy, which was increasingly performed along the period of study.
Phraseme mit übernatürlichen Komponenten und Pseudo-Kinegramme
Authors: Pavić Pintarić Anita , Valenčič Arh Urška
Published: September 2020

Dieser Aufsatz befasst sich mit Phrasemen, die
übernatürliche Komponenten wie Gott, Teufel oder Engel enthalten, und mit
Pseudo-Kinegrammen, d. h. Phrasemen, die auf Bewegungen hinweisen, die als
ungewöhnlich, fast übernatürlich verstanden werden können. Ziel ist es, Dialoge
der kroatischen und slowenischen Literatur für Kinder und Jugendliche zu
untersuchen, in denen die Figuren miteinander in Konflikt stehen. Es wird davon
ausgegangen, dass diese Phraseme in literarischen Dialogen verwendet werden, um
das Gesagte hervorzuheben oder sich mit Beschreibungen des nonverbalen Verhaltens auf Emotionen zu beziehen. Die Arbeit zielt darauf ab, folgende Fragen zu beantworten:
In welchen Konfliktsituationen und an welcher Textstelle werden die
untersuchten Phraseme verwendet? Welche Funktionen haben die untersuchten
Phraseme in Konfliktsituationen? Werden die untersuchten Phraseme in den
Konfliktsituationen in ihrer üblichen oder geänderten Form verwendet?
Analiza tvorbenih načina u hrvatskome nazivlju arhitekture i urbanizma s osobitim osvrtom na značenje
Authors: Borić Neda
Published: September 2020

U radu se korpusnim tipom istraživanja analiziraju tvorbeni načini u hrvatskome nazivlju arhitekture i urbanizma. Na temelju dobivenih rezultata izvedena je njihova tipologija i opisane su njihove specifičnosti. Analiza je upotpunjena osvrtom na semantičke aspekte koji ukazuju na čvrstu isprepletenost morfoloških i značenjskih aspekata u stvaranju naziva ovisno o specifičnome kognitivnom makrokontekstu, odnosno specifičnoj domeni upotrebe. Rad može koristiti budućim istraživanjima nazivljā drugih struka te poslužiti kao polazište u radu na normizaciji i usustavljivanju nazivlja arhitekture i urbanizma.
Značenja sufiksa -suz u bosanskom jeziku
Authors: Bulić Halid
Published: September 2020

Među riječima koje su u bosanski jezik došle iz turskog jezika mnogo je onih koje su tvorene sufiksom -suz. Osnovno značenje sufiksa -suz u turskom jeziku je ‘bez’, odnosno ‘odsustvo onoga što je iskazano osnovom riječi’. Ono se obično zadržava i u posuđenicama u bosanskom jeziku. Međutim, istraživanje pokazuje da to nije uvijek tako. U savremenom bosanskom jeziku postoji više riječi u kojima sufiks -suz ima značenje drukčije od izvornog, odnosno u kojima ne označava odsustvo ili nedostatak onoga što je kazano osnovom riječi. Većina posuđenica iz turskog u bosanski jezik koje se završavaju sufiksom -suz označavaju odsustvo nečeg što je dobro i poželjno pa, prema tome, označavaju negativne pojave. Zbog toga je novo značenje sufiksa -suz ‘nosilac loše osobine’. Takvo je značenje prisutno u riječima hatèrsuz, belájsuz, problémsuz, drvènsuz, harámsuz, beznafàksuz i bezbismilèsuz.
Prosecuting Attorneys in a Democracy – A California Perspective
Authors: McKinley Patrick
Published: September 2020

A prosecuting attorney in a democracy is very important in the processing of criminal cases- from pre-filing to final appeal. Much of the involvement of the District Attorney, both before a criminal case is filed, and during the prosecution of the case, stems from the “Exclusionary Rule”. It is the usual case that the police will bring their investigation, their arrest warrant or search warrant affidavit to a District Attorney to review it prior to taking it to the judge. In this connection, District Attorneys will themselves reject 5-10% of the warrant requests submitted to them for approval, often asking law enforcement to do some further investigation before resubmitting the warrant. Furthermore, because of the Doctrine of Separation of Powers, only the District Attorney or the California State Attorney General can make the decision to file or not file a case. This Article illustrates the impact of such discretion. The problem of democracy is strictly connected to the process of DA’s selection, what has also been here presented. Another fundamental issue is a role of DA in voir dire, mainly because jury trials are guaranteed by the federal Constitution and are associated with the idea of democracy. Separation of Powers and Judicial Control of the DA, the police, and the sentencing of those convicted of crimes have been analyzed from the perspective of the California law. Additionally, the article includes final comments on the technological progress and its impact on criminal law and democracy. All the conclusions have been made in reference to Author’s experience as Assistant DA in California.
Academic Freedom: a Choice Between Conservative or Liberal Perceptions – the Case of the United States
Authors: Maćkowska Katarzyna Teresa
Published: September 2020

It is only the minimum extent to which the law becomes the instrument of coping with social tautness regarding the academic freedom. On the one hand, legal provisions significantly limit the number of cases related to hate crimes but on the other, they sometimes narrow a discussion due to difficulties in harmonizing individual’s rights and campuses’ perception - a phenomenon, which in the U.S. had been called as “chilling” the freedom. Undoubtedly, the enactment of free speech or academic freedom regulations at universities is necessary as it helps to prevent from a “hate speech” but the legal shape of this process has been strictly connected to a determination for either liberal or conservative description of the academic freedom.
Regarding the newest Niche’s rankings, ten universities have been selected, five out of the most liberal and five the most conservative public ones. Furthermore, two catholic universities have been added to describe differences in defining the academic freedom. Moreover, some references have been made to the U.S. Supreme Court decisions, and the very fundamental documents, namely the 1940 Statement and Harvard Free Speech Guidelines. In the separate article a problem of legislative acts that had been enacted for the past two years in a response to Report of the Committee on Freedom of Expression by the University of Chicago of 2014 will be covered. A few remarks upon this matter have been hereby made, though.
The article is based on a dogmatic legal method, including quotations of legal sources and their subsequent analysis.
STATUS HUKUM TANAH KERATON KASEPUHAN CIREBON SETELAH BERLAKUNYA UNDANG-UNDANG NOMOR 5 TAHUN 1960 TENTANG PERATURAN DASAR POKOK-POKOK AGRARIA
Authors: Murbarani Thanisa Dita
Published: September 2020

This study aims to analyze and determine the legal status of the land of the Kasepuhan Palace in Cirebon after the enactment of Law Number 5 of 1960 concerning Basic Agrarian Regulations. The results show that the legal status of the Kasepuhan Sultanate lands has been transferred to the state based on the Fourth Dictum letter A Law Number 5 of 1960 concerning Basic Agrarian Principles and the land is redistributed as the object of the provisions regarding land reform on the legal basis of Article 1 Government Regulation Number 224 of 1961. It is very inversely proportional to assuming that the Kasepuhan Palace land is not and has never become self-government, then the legal status of the Kasepuhan Palace land is fully controlled as customary land / wewengkon land / prohibited forest belonging to the Kasepuhan Palace Cirebon. The problem is, based on authentic evidence, the Kasepuhan Palace has never been self-governing, but the lands controlled from generation to generation or the land of the Keraton Kasepuhan Cirebon are still redistributed by the government. So, the legal status of the Kasepuhan Palace lands is currently unclear.

Keywords:

Keraton; Land; Cirebon.
Problematika Pemilihan Kepala Daerah Calon Tunggal Dalam Demokrasi Indonesia
Authors: Ishak Nurfaika
Published: September 2020

This study aims to explain the arrangements for a single candidate regional head election and how people's sovereignty is channeled into the democratic process of regional head elections. This type of research is a descriptive normative juridical study. The data used are secondary data in the form of primary legal materials and secondary legal materials obtained through literature study. The results showed that the regulation of regional head elections with only 1 (one) pair of candidates began with the issuance of the Constitutional Court decision Number 100 / PUU-XIII / 2015 which was subsequently followed by the issuance of General Election Commission Regulation Number 14 of 2015 and Law Number 10 of 2016. Whereas the people are the determinants of government administration power through the regional head election process so that the people as the main activator of the wheel of democracy should not be hindered in choosing candidates for regional head leaders even though there is only one pair of candidates involved in the election. Election of heads must be carried out honestly and fairly so that political awareness by all citizens can be realized.

Keywords: Local Elections; Sovereignty; Democracy.
Relación entre la ocupación y la automedicación en adultos mayores de 65 años en adelante, en la parroquia el Sagrario, Cuenca-Ecuador, 2017
Authors: Bravo Angamarca Lourdes Alejandra
Published: September 2020

Relacionar la ocupación con la automedicación en adultos mayores de 65 años de edad en la parroquia el Sagrario, Cuenca-Ecuador, 2017. La metodología aplicada fue de tipo caso-control porque se buscó asociar la relación entre 2 variables, la ocupación y automedicación. Utilizando la encuesta dirigida como instrumento se realiza una investigación de campo. La población estuvo conformada por 801 personas mayores de 65 años de edad que residen en la parroquia El Sagrario, se obtuvo una muestra de 417 personas que representan la totalidad de la población. La misma que fue calculado considerando la diferencia entre los dos grupos de estudio concluyendo un tamaño muestral de 116 personas, constituida a su vez por 58 personas en casos y 58 personas en los controles. Para determinar la exposición al factor de riesgo se obtuvo 47 casos y 42 controles expuestos, y 11 casos y 16 controles no expuestos. Se reporta que el Odds Ratio es de 1.628 con IC de (0;4) por lo tanto se interpreta que la ocupación no tiene asociación con la automedicación y es un factor de protección.
Perfil epidemiológico de patologías apicales en pacientes que acuden a centros de atención odontológica en Cuenca (Ecuador)
Authors: Cedillo Orellana Sara Ivanna
Published: September 2020

Objetivo: Definir el perfil epidemiológico de las patologías apicales en la ciudad de Cuenca-Ecuador en el período marzo 2017 - febrero 2018. Materiales y métodos: Se realizó un estudio retrospectivo, basado en el análisis de 785 fichas clínicas del área de endodoncia correspondientes a pacientes atendidos en centros de atención odontológica en la ciudad de Cuenca (Ecuador) en el período marzo 2017-febrero 2018. Resultados: El 29,17 % de los pacientes atendidos presentaron algún tipo de patología apical. Estas patologías se presentan principalmente en pacientes de sexo femenino, con edades comprendidas entre los 26 y los 35 años y cuya ocupación se clasifica dentro de la categoría “ocupaciones elementales”. Conclusión: Existe una moderada frecuencia de patologías apicales en los pacientes que son remitidos al área de endodoncia de centros de atención odontológica de la ciudad de Cuenca. Esto muy probablemente es el resultado de patologías pulpares no atendidas oportunamente.
La ocupación como factor de riesgo para la automedicación en jóvenes:Casos y controles
Authors: Cárdenas Fernández Bryan
Published: September 2020

Objetivo: El objetivo del estudio fue determinar la relación entre la ocupación y la automedicación en adultos de 18-44 años en la parroquia el Sagrario de Cuenca en el año 2017. Materiales y Métodos: Se llevó a cabo un estudio de caso control, retrospectivo observacional en la parroquia Sagrario. La muestra fue de 236 personas, se obtuvo 112 hombres y 124 mujeres, calculada con la fórmula de 2 grupos de variable cualitativa. Se registra una mayor distribución de la muestra entre personas de 18 a 25 años con 158 del total de la muestra. Para la evaluación del riesgo se utilizó la encuesta de Andrea Conhi. Los datos recolectados fueron registrados en el programa de libre acceso EPI INFO versión 7.2. Resultados: De acuerdo al análisis realizado en los participantes, para determinar la exposición al factor de riesgo tuvimos 101 casos expuestos, 88 controles expuestos, y 17 casos no expuestos, 30 controles no expuestos, obteniendo un Odds Ratio de 2.025 comprobando que la ocupación si es factor de riesgo de la automedicación. Conclusiones: La ocupación es un factor de riesgo para la automedicación en personas de 18 a 44 años de la parroquia el Sagrario de la ciudad de Cuenca en el año 2017.
Uso de CBCT y herramientas computacionales odontológicas para la reconstrucción tridimensional de objetos arqueológicos.
Authors: Cazar Marcelo Enrique
Published: September 2020

Las tomografías computarizadas de haz cónico (CBCT) proporcionan imágenes 3D de alta calidad con resoluciones submilimétricas, con tiempos de exploración bastante cortos (10 a 70 segundos) y dosis de radiación hasta 15 veces menor que los sistemas clásicos de tomografías. Gracias a esto, su uso en diferentes ámbitos, tanto en odontología como en otras áreas, ha aumentado significativamente. Adicionalmente, el avance de la teleradiología y la compatibilidad de las imágenes DICOM resultantes con distintos tipos de software de planificación, simulación e impresión 3D; han permitido consolidar una herramienta potente para el posible diagnóstico temprano y preciso de distintas lesiones profundas, anomalías y la adquisición de un conocimiento profundo sobre un área maxilofacial específica y su relación con las estructuras adyacentes. Sin embargo, sus mediciones resultantes con muy poco rango de error y la posibilidad de generar reconstrucciones tridimensionales la pintan como un claro instrumento pedagógico y de gran utilidad en técnicas modernas de investigación arqueológica, tecnológica, forense, antropológica y biomédica. Este artículo, proporciona una descripción general de los sistemas de CBCT, sus tecnologías computacionales asociadas y demuestra su aplicabilidad como herramientas para el análisis, preservación, reconstrucción y reproducción de piezas arqueológicas. A modo de prueba, se describe su aplicación en la adquisición de distintos modelos estereolitográficos de restos arqueológicos del Museo Pumapungo de la ciudad de Cuenca, Ecuador.
A new concept of motion preservation surgery of the cervical spine: PEEK rods for the posterior cervical region
Authors: Aydin Ahmet Levent , Sasani Mehdi , Erbulut Deniz Ufuk , Oktenoglu Tunc , Ozer Ali Fahir
Published: September 2020

BACKGROUND: Laminectomy may cause kyphotic postoperative deformity in the cervical region leading to segmental instability over time. Laminoplasty may be an alternative procedure to laminectomy, as it protects the spine against post-laminectomy kyphosis; however, similar to laminectomy, laminoplasty may cause sagittal plane deformities by destructing or weakening the dorsal tension band. OBJECTIVE: Using finite element analysis (FE), we attempted to determine whether a posterior motion preservation system (PEEK posterior rod system concept) could overcome the postoperative complications of laminectomy and laminoplasty and eliminate the side effects of rigid posterior stabilization in the cervical region. METHODS: We compared PEEK rods in four different diameters with a titanium rod for posterior cervical fixation. The present study may lead to motion preservation systems of the cervical vertebra. RESULTS: When PEEK rod is compared with titanium rod, considerable increase in range of motion is observed. CONCLUSIONS: PEEK rod-lateral mass screw instrumentation systems may be useful in motion preservation surgery of the posterior cervical region.
Miles Conrad Award 2020: A panel discussion with James Neal, Deanna Marcum, and Todd Carpenter
Authors: Neal James G. , Marcum Deanna , Carpenter Todd
Published: September 2020

This paper is based upon a panel discussion that took place after James G. Neal gave his 2020 Miles Conrad Award address during the inaugural NISO Plus conference that was held in Baltimore, MD (USA) from February 23–25, 2020. The discussion was a thoughtful conversation among three information industry leaders - Neal, Deanna Marcum, and Todd Carpenter - that touched upon many of the issues that continue to swirl within the information community today, such as information literacy, information access, policy awareness and advocacy, digital preservation, collaborative initiatives, diversity, information access and control, etc. There were no clear solutions to the issues, but there was general agreement that the future success of all stakeholders requires that we identify those things where we have common interests and common concerns and build the capacity for legal, legislative, and policy advocacy that will allow all stakeholders to be players not only in their communities, but also, and perhaps even more importantly, in Washington, D.C. and in international venues where global information policies are being set.
Bistable permanent magnet actuator based on double wing magnetic flux
Authors: Zhao Yang , Li Yong , Shen Yunde
Published: September 2020

This letter presents a bistable permanent magnet actuator, based on double wing magnetic flux (DWMF) formed by the structure of welding sleeve and slotted armature. The double wing magnetic flux consist of high wing magnetic flux (HWMF) and low wing magnetic flux (LWMF), resulting in bistable performance under differentiating control. Parameters improvement around DWMF is analyzed based on modeling, and optimized results for a prototype actuator are obtained. The experimental and simulation results agree well, and show that the prototype actuator can realize bistable performance under the DC step voltage drive, with the holding force of 8.2 N (without current) and the restoring force of −31.7 N (with negative current), the dynamic results show that the displacement response time within 8 mm is 28 ms, of which the actuation time is 16.5 ms, the transient maximum power consumption of the restoring period is 18 W.
Probabilistic evaluation of detection capability of eddy current testing to inspect pitting on a stainless steel clad using multiple signal features
Authors: Tomizawa Takuma , Song Haicheng , Yusa Noritaka
Published: September 2020

This study proposes a probability of detection (POD) model to quantitatively evaluate the capability of eddy current testing to detect flaws on the inner surface of pressure vessels cladded by stainless steel and in the presence of high noise level. Welded plate samples with drill holes were prepared to simulate corrosion that typically appears on the inner surface of large-scale pressure vessels. The signals generated by the drill holes and the noise caused by the weld were examined using eddy current testing. A hit/miss-based POD model with multiple flaw parameters and multiple signal features was proposed to analyze the measured signals. It is shown that the proposed model is able to more reasonably characterize the detectability of eddy current signals compared to conventional models that consider a single signal feature.
From centralized to decentralized power system: A space-analysis for France
Authors: Cluet Raphaël , Maïzi Nadia , Mazauric Vincent
Published: September 2020

This paper reviews the conditions for ensuring the space consolidation and time reconciliation of all scales involved in power system energy planning. At the upper space scale, a simplified description of the grid based on the Kuramoto model is adopted to assess the stability of the synchronism state of the power system. The consequences of a massive dissemination of renewables for the future of the power system is addressed in the case of France in a long-term planning exercise up to 2050. Attention is paid to how the new capacities are dispatched among the administrative regions. While a favorable impact of sparse generation on the synchronism is obtained, the constraint on the inertia provided by the kinetic energy has to be endogenized to enforce an operable power mix under admissible disturbances.
Digital fluxgate current sensor based on second harmonic detection
Authors: Wei Yutong , Wang Yang , Wang Meiling , Ye Chaofeng
Published: September 2020

This paper presents a new digital fluxgate current sensor based on second harmonic detection for DC and AC measurement. The sensor utilizes a feedback loop to obtain an almost zero-flux condition, i.e., a balance between the magnetic flux of the primary current and the feedback current, in which way the feedback current is proportional to the primary current. The AC magnetic flux is detected with an induction coil, and the DC zero-flux condition is realized by magnetic saturation effect method, where the magnetic core is periodically magnetized and then the second harmonic of the magnetization current is calculated as an indication of the DC magnetic flux. After theoretical derivation, the operating principle of the sensor was investigated using a numerical simulation model built with Simulink of MATLAB. In addition, a prototype sensor was developed and tested. The experiment results demonstrate that the current sensor works properly for DC and AC measurement. The average error is about 0.06% for DC measurement.
A narrowband active noise control algorithm considering the harmonic distortion of the loudspeaker
Authors: Cai Yinshan , Dong Longlei , Zhou Yanxin
Published: September 2020

Electrodynamic loudspeakers are the main actuators of the active noise control system, and their harmonic distortion has a detrimental effect on the noise reduction of the system. To improve the performance, this paper proposes a novel narrowband active noise control algorithm with compensating the nonlinearity of the loudspeaker. In the proposed algorithm, the parameters of the controller are obtained by iteration through the filtered-x least mean square algorithm. Meanwhile, they are adjusted in real-time by establishing the online inverse model of the loudspeaker using the Volterra expansion. The simulation experiments for the typical loudspeaker model show that the proposed algorithm can dramatically improve noise reduction compared to the conventional algorithm.
Rectangular wave eddy current testing using for imaging of backside defects of steel plates
Authors: Sasayama Teruyoshi , Yoshimura Wataru , Enpuku Keiji
Published: September 2020

Accurate, easy, and fast inspection of defects on the backside of thick steel plates is essential for the maintenance of infrastructures. Low frequency eddy current testing (LF-ECT) is a promising method to detect defects of the backside of steel plates, with a thickness of approximately 10 mm. However, it is possible that the signal from the backside defect is smaller than that from the surface magnetic noise, causing difficulty identifying the backside defect. In this study, we propose a method to reduce the surface noise by employing a square wave inverter to generate a harmonic signal (rectangular wave ECT, or RECT), and the result demonstrates that the surface noise is successfully reduced using the harmonic signal.
Dynamical analysis and control of rotatory manipulators with time varying mass loads
Authors: Ma Chicheng , Jing Dong , Shao Mingyu , Yu Hui , Guo Zonghe
Published: September 2020

Manipulators are widely used in industrial fields as automation equipment and robotic structures. Besides moving objects, manipulators often work with variable payloads, and the residual vibration significantly affects the position accuracy of manipulators. This paper mainly investigates the dynamic characteristics of flexible manipulators with time varying mass payloads and active control of the residual vibration is carried out. Finite element method is utilized to construct the dynamical model, and responses of the system are calculated by Bathe’s method. The influence of the time varying mass is analyzed in details, including an increasing mass case and a decreasing mass case. Then active control of the residual vibration is given based on a PID controller. To improve the control effect, genetic algorithm (GA) is applied to tune the parameters of the PID controller. Simulations demonstrate that the time varying mass affects the residual vibration of the system remarkably. For a decreasing mass system, a nonstructural negative damping is induced and the residual vibration may be strengthened, while for an increasing mass system, a nonstructural positive damping is caused and the residual vibration may be attenuated. The comparison of the control methods demonstrates that the GA-PID controller results in a significant improvement in the vibration reduction.
Experimental verification of a TE01 mode converter to locate a crack in a metal pipe
Authors: Katagiri Takuya , Chen Guanren , Yusa Noritaka , Hashizume Hidetoshi
Published: September 2020

In this study, a TE01 mode converter was developed to locate an axial crack on the inner surface of a metal pipe. Three-dimensional finite element simulation was conducted to evaluate the effect of inserted coaxial cables on the transmission characteristic of the mode converter. The result showed that the energy of TE mode microwaves leaned to transmit to one side when the cables penetrated with inclination. To demonstrate the effectiveness of the mode converter, experimental verification was conducted. The mode converter was fabricated based on the simulation result. Microwaves were emitted through the pipe wall of the converter to propagate on both sides (‘right side’ and ‘left side’) of a pipe with an artificial slit. Compared with the signals from each side, the reflection from the slit on the right side was more significant than that on the left side. This result is consistent with the numerical simulation result.
Feasibility study of detecting the end contacting status of threaded-sleeve-connected reinforcing bar using magnetostrictive guided wave
Authors: Hu Chaoyue , Xu Jiang , Li Yunfei
Published: September 2020

The reinforcing bar connected by threaded sleeve is widely used. The end contacting status under the sleeve indicates the tightness of the threaded sleeve connection. In this paper, the feasibility of using magnetostrictive guided wave to detect the end contacting status of the reinforcing bar is studied. Firstly, the propagation characteristic of the wave propagating through the threaded sleeve connection is analyzed. The end contacting status affects the reflection and transmission of the wave. Then, experiments are carried out on a thread-sleeve-connected reinforcing bar. The passing signals of the threaded sleeve connection at an exciting frequency of 30 kHz can be used to distinguish end contacting status of the reinforcing bar. Additionally, the peak voltage of the passing signal’s first passing wave decreases with the increasing loosening angle of the threaded sleeve connection. The study proves the feasibility of detecting the end contacting status using magnetostrictive guided wave.
Micro-power-generator for energy harvesting from vortex induced vibration
Authors: Chen Yuansheng , Gu Cong , Wang Hao , Qiu Jinhao , Zhao Sunchong
Published: September 2020

A micro-power-generator is developed with piezoelectric ceramics, which can convert the structural vibration energy generated by wind power into electricity to provide energy for micro-devices such as wireless sensor nodes. The vibration modes of the device are analyzed. The standard interface circuit for piezoelectric energy recovery and LTC3588-1 voltage stabilization circuit are selected, and the hardware circuit of the device is designed. The output voltage and power characteristics of micro-power-generator were analyzed under different loads, frequencies and amplitudes. The experimental results show that under the same wind speed, When the blunt body is a cuboid, the power generation effect of this device is the best under the optimal load, with the maximum output power of 350.7 μW. Under the same load with the same shape and structure, the load voltage and output power increase with the increase of wind speed.
Characteristic analysis of flux switching PM machine with various pole and slot combinations
Authors: Azeem Muhammad , Kim Byungtaek
Published: September 2020

This paper examines the influence of pole and slot combinations on the electromagnetic performance of the flux-switching permanent magnet (FSPMs) machine. For this purpose, first the production of air gap flux density in machine analytically discussed. Next, five different pole and slot combination are selected by using the knowledge of air-gap flux density expression. The performances of the different combinations are analyzed and compared using the finite element analysis (FEA), and optimal pole and slot combination is suggested. It is found that the pole and slot combination has a dominant effect on machine performance and needs to be considered during the design stage.
Effect of different vacuum on field emission of carbon nanotube arrays
Authors: Hu Jiaming , Bai Baodong , Chen Dezhi
Published: September 2020

In this paper, the electron-molecule collision ionization is added to field emission under non-vacuum conditions, and the change of emission current caused by vacuum adjustment in field emission of carbon nanotubes is explained. The field emission current density equation under non-vacuum conditions is established. Through the theoretical analysis and the processing of experimental data, it can be concluded that when other variables are controlled unchanged, the change of pressure will affect the concentration of gas molecules in the air and the collision probability with electrons, then the density of emission current is changed. The study has a certain reference value for the application of field emission in low vacuum and atmospheric pressure.
Hard-point detection of catenary based on Hidden Markov Model
Authors: Tian Shuxia , Zhang Penghui , Huang Liping , Song Xueqian , Chen Zhenmao , Liu Jianxiu , He Wenbin , Cao Yang
Published: September 2020

Hard-point detection is an important content of catenary detection. In this paper, the pantograph-catenary coupling model was established firstly. Then the vertical acceleration of pantograph during operation was calculated by using three-dimensional modeling software and finite element analysis software. The acceleration signal mixed with white noise was filtered by global default threshold, and the hard-point detection feature signal was obtained. Finally, the Hidden Markov Model corresponding to each state of the hard-point was obtained by using the characteristic signal, which verified the feasibility of the Hidden Markov Model for hard-point detection.
Output power improvement of a vernier motor using field winding configuration
Authors: Rashid Kashif , Azeem Muhammad , Kim Byungtaek
Published: September 2020

In this paper, a field winding vernier (FWV) machine is proposed to get higher back electromotive force (EMF) than surface permanent magnet vernier (SPMV) machine. First, the magneto motive force (MMF) equation of FWV machine is derived to obtain the requisite field current to produce the same back EMF as SPMV machine. Using the derived equation, the surface current density is also estimated and compared with the maximum allowable current density to examine the possibility of improving the back EMF of the FWV machine and find the slot-pole combination that is advantageous for the FWV structure. Using the obtained information, three models of SPMV and FWV machines are designed, finite element analysis are performed, and it is verified that proposed FWV machine has the capability of producing higher back EMF than SPMV machine.
Study on the conductivity model of SCC by using a new eddy current probe
Authors: Zhang Dongli , Wu Meixian , Chen Zhenmao , Li Yong
Published: September 2020

Usually, the stress corrosion crack (SCC) has a complex shape of non-zero conductivity. Its shape is very difficult to reconstruct accurately by using eddy current testing signals. At present, most defaults being dealt with are shallow cracks with a simple shape, which are not consistent with the actual cases. In order to detect the deep SCC in metal materials quantitatively, a new eddy current probe with capability of deep penetrating is proposed in the paper. Based on the research results of current literature, the conductivity model of deep SCC is established. ANSYS software is used to analyze the influence of crack inclination, branching position and branch number on eddy current signals to build the equivalent model of SCC. Simulation results show that the new probe is more sensitive to complex SCC than the conventional pancake probe, and can distinguish whether the SCC having branches or not and what the branching position is. The quantitative results of SCC obtained by using a calibration curve show that the detection signals picked up by the new probe can effectively be used to deduce the depth of branching SCC.
Performance analysis of magnetic gear with Halbach array for high power and high speed
Authors: Kim Se-Yeong , Lee Tae-Woo , Chun Yon-Do , Hong Do-Kwan
Published: September 2020

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.
Mathematical modeling analysis and verification of vibration isolation parts of washing machine
Authors: Jiang Jinhui , Qu Yidan
Published: September 2020

Washing machines are used very frequently in everyday life. There have been many related studies on the vibration and noise of washing machines. The suspension system is an important vibration isolation component of the washing machine. Based on the Lagrangian equation, the dynamic model of the suspension system was established. The reliability of the model was verified by finite element simulation and experimental methods. Finally, this paper used a multi-objective optimization method to obtain optimal parameters of the washing machine and further to reduce the vibration level of washing machines.
A study on torsional guided wave EMAT array and its application in embedment depth inspection of guardrail post
Authors: Zhang Yinghong , Wang Bin , Wei Xiao , Qian Zhenghua
Published: September 2020

It is always a challenge to quickly and effectively inspect the embedment depth of highway guardrail posts. This paper focuses on an electromagnetic ultrasonic transducer (EMAT) array that can excites torsional mode (T-mode) guided waves and applies it to check the embedment depth of guardrail posts. First of all, we presented a torsional guided wave EMAT array that can be used to quickly inspect the embedment depth of guardrail posts. The working principle of the EMAT array was described in detail. Secondly, a torsional guided wave EMAT array composed of 12 racetrack coils and 24 permanent magnets was simulated to verify the excitation and propagation process of torsional guided wave in a post. Then, a method for detecting the embedment depth of a post using the travel time of a torsional guided wave in the post was put forward. Finally, an experimental system was set up to carry out embedment depth detection experiments on posts with different depths buried in soil and concrete. Experiments have verified the feasibility of using the torsional guided wave EMAT array to inspect the embedment depth of the guardrail post.
Comparative study of thrust of U-shaped ironless permanent magnet synchronous linear motor based on analytical method and finite element analysis
Authors: Yang Zhihui , Liu Ren , Xia Bin
Published: September 2020

Due to the large transverse edge effect for U-shaped ironless permanent magnet synchronous linear motor affect the distribution of air gap magnetic field is large, it will reduce the no-load back electromotive force and thrust. This paper proposes a novel method to evaluate the effect of transverse edge effect based on Kriging surrogate model. By comparing the results of the two-dimensional and three-dimensional finite element analysis of the air gap magnetic field of the motor, it can be seen transverse length of the motor, air gap height and thickness of the permanent magnet are the main influencing factors.
Thickness measurement for non-ferromagnetic metal under the large liftoff based on the last peak point of differential pulsed eddy current signals
Authors: Song Yun , Wu Xinjun
Published: September 2020

Pulsed Eddy Current Testing (PECT) has been used to measure the wall thickness of ferromagnetic metallic component with thick insulation. However, for the non-ferromagnetic metallic component, there is still the problem to be solved. The main purpose of this study is to find an effective feature, to measure wall thinning of the non-ferromagnetic metallic component under the large liftoff, and further expand application of the PECT technology. Hence, the time to the last peak point (TLPP) is proposed based on the analytical predicted signals. Furthermore, the influence of the variable liftoff is studied, and the error caused by the liftoff is within the acceptable range. Two sets of experiments are conducted to test the performance of the TLPP under various liftoffs. The results show that when the wall thickness is reduced by more than 40%, the measurement error based on the TLPP is within 11%.
Measurement of directionality in carbon fiber reinforced plastic composite with eddy current testing
Authors: Cheng Jun , Yu Cheng , Xu Shuai , Qiu Jinhao , Takagi Toshiyuki , Xu Dezhang
Published: September 2020

In carbon fiber reinforced plastic (CFRP) composite, the alignment of continuous carbon fibers guides the directional flow of eddy currents, which is beneficial to the structural and damage detection. In this study, for the purpose of impact damage repair, the transmitter-receiver (T-R) and the flat-tangent eddy current probes are used to determine the fiber orientations and stacking sequence in the CFRP laminate by surface scanning. Theoretical analysis shows that the T-R probe can flexibly pick up the magnetic field generated by the stretched eddy current in CFRP layers. In the meanwhile, the flat-tangent probe possesses layer selective characteristics. By calculating the fiber distribution images of individual directions based on two-dimensional fast Fourier transform (2D-FFT) and comparing the order of pixel intensity values of these images, the fiber orientation and the stacking sequence in the laminate plates can be obtained simultaneously, which provides guidance for damage detection and repair of the CFRP structures.
Numerical and experimental analysis of turbulent boundary layer control with piezo-ceramic actuator
Authors: Li Dawei , Li Guijuan , Sun Lin , Chen Yunfei
Published: September 2020

The effects of smart-material-based active surface perturbation (i.e. piezo-ceramic actuators) on wall shear stress and noise metric have been investigated by simulations and wind tunnel experiments. A periodic vibration through the application of piezo-ceramic actuators is imposed on the surface of a plate, and the vibration position is located on the upper part of the leading edge of the plate. Both the control results from simulations and experiments are close to each other, when the control parameters are the same. The simulations and wind tunnel experiments show that downstream skin-friction drag and noise metric can be reduced with the active control, and the reductions strongly depend on control parameters. Comparing with the near wall flow structures, the turbulent kinetic energy and characteristic turbulence length scale in the turbulent boundary layer can be controlled with the piezo-ceramic actuator.
A fuzzy evaluation method of road vehicle automatic weighing instrument in dynamic force metrological performance
Authors: Mao Xiaohui , Fei Liping , Shang Xianping , Chen Jie , Zhao Zhihao
Published: September 2020

The measurement performance of road vehicle automatic weighing instrument installed on highways is directly related to the safety of roads and bridges. The fuzzy number indicates that the uncertain quantization problem has obvious advantages. By analyzing the factors affecting the metrological performance of the road vehicle automatic weighing instrument, combined with the fuzzy mathematics theory, the weight evaluation model of the dynamic performance evaluation of the road vehicle automatic weighing instrument is proposed. The factors of measurement performance are summarized and calculated, and the comprehensive evaluation standard of the metering performance of the weighing equipment is obtained, so as to realize the quantifiable analysis and evaluation of the metering performance of the dynamic road vehicle automatic weighing instrument in use, and provide data reference for adopting a more scientific measurement supervision method.
Study of multiple-site structural damage detection application using vibration response
Authors: Miao Bingrong , Yang Shuwang , Wang Mingyue , Jiang Chuanying , Peng Qiming , Luo Yaoxiang
Published: September 2020

The identification effects of different modal parameters (displacement mode, rotation mode, and curvature mode) of the beam structure on structural damage during crack initiation are studied in this paper. Firstly, the displacement mode, the rotation mode and the curvature mode of the two-span simply supported beam are calculated using the vibration response. Secondly, combining the multi-resolution and singularity analysis characteristics of continuous wavelet transform, the wavelet transform coefficients of three modal parameters are calculated to identify the singularity of structural modal parameters. Thirdly, the recognition effects of each method on structural damage are compared by adding different degrees of random noise to the simulation data. The results show that the damage identification methods based on three different modal parameters can locate small-scale structural damage, but the anti-noise performance of each method is different, the anti-noise performance of the rotation mode is the best, the displacement mode is second and the curvature mode is poor. Finally, the experimental data is used to verify the recognition effect of each damage identification method based on different modal parameters on the actual structural damage. The experimental results show that the damage recognition effect of the rotation mode parameters is better, while the displacement mode and the curvature mode parameters are similar, but the curvature mode method is more likely to be interfered at the smaller damage. These analysis results provide a reference for the selection of different damage identification parameters according to the environment and response characteristics in engineering practice.
Accuracy of parent-reported ages and stages questionnaire in assessing the motor and language skills of preterm infants
Authors: Hwarng G. Y. H. , Ereno I. L. , Ho S. K. Y. , Allen J. C. , Moorakonda R. B. , Yeo C. L.
Published: September 2020

BACKGROUND:

Parent-completed tools like the Ages and Stages Questionnaire Third Edition (ASQ-3) are important in developmental screening. As a screening tool, a high negative predictive value (NPV) is critical to avoid missing the diagnosis of developmental delay. This study evaluated the NPV and accuracy of the ASQ-3 in assessing the development of preterm infants.

METHODS:

Infants born at <32 weeks and/or <1250 grams, presenting to the Neonatal Neurodevelopmental Clinic at the Singapore General Hospital for follow-up from January 2014 to June 2017, at 6, 12, and 18 months corrected age, were included. The ASQ-3 and standardized tests – Peabody Developmental Motor Scale-Second Edition (PDMS-2) and Preschool Language Scale, Fourth Edition UK (PLS-4 UK) – were administered. ASQ-3 gross motor and fine motor scores were compared to PDMS-2 at 6 and 12 months, and ASQ-3 communication scores to PLS-4 UK at 18 months.

RESULTS:

At 6 months ( n = 145), NPV for gross motor and fine motor were 96.4% (accuracy 80.0%) and 95.4% (accuracy 77.2%) respectively. At 12 months ( n = 127), NPV for gross motor and fine motor were 88.9% (accuracy 79.8%) and 82.8% (accuracy 74.0%) respectively. At 18 months ( n = 113), NPV for language was 56.9% (accuracy 63.7%).

CONCLUSIONS:

The ASQ-3 showed high NPV and accuracy in screening gross motor and fine motor skills at 6 and 12 months, but not in screening language skills at 18 months. Judicious use of the ASQ-3 may allow for more effective utilization of resources.
Sobre el I plan de desarrollo
Authors: Gorosquieta Francisco Javier
Published: September 2020

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La sociología de Marx
Authors: Prieto Carlos
Published: September 2020

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