bluuebunny/crossref_metadata_2025 huggingface dataset:
Appropriate Testing of Isothiazolinones in Children
Authors: Goldenberg Alina , Lipp Michael , Jacob Sharon E.
Published: January 2017

Background/Objective

The isothiazolinones methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) are prevalent pediatric contact sensitizers. MI allergic contact dermatitis (ACD) is underreported in the literature. The objective of the current study was to use a database of provider‐reported U.S. pediatric patch test cases to evaluate the positive patch test (PPT) prevalence rates of the combined preservative test substrate MCI/MI and of MI alone.

Methods

U.S. pediatric patch test providers in all 50 states who had joined the registry were invited to submit deidentified cases to the database. More than 1100 logged cases in the database were evaluated for PPTs to MCI/MI combination, MCI/MI and MI, and MI alone.

Results

Within 1 year of data collection, 96 cases with a PPT for MCI/MI, MCI/MI and MI, and MI alone were identified; 37 of these were positive to MCI/MI, with MI alone not tested or negative, and 39 were positive to MI only, with MCI/MI and MI tested. Fifteen (41%) of the MCI/MI cases were detected using an epicutaneous patch test alone and 22 cases (59%) using comprehensive patch testing. Only one case (3%) of MI alone sensitization was detected using T.R.U.E. plus a supplemental panel of tests; the remaining 38 cases (97%) were detected using comprehensive testing. Testing with only the combined MCI/MI preservative substrate may miss 51% of MI allergies.

Conclusion

Appropriate testing of isothiazolinones is needed to clarify the true prevalence of sensitization to these allergens and the burden of pediatric ACD. Patch testing for MI alone in addition to MCI/MI combination is warranted in children with recalcitrant dermatitis.
Varied Presentations of Pediatric Lipoblastoma: Case Series and Review of the Literature
Authors: Shen Lisa Y. , Amin Sapna M. , Chamlin Sarah L. , Mancini Anthony J.
Published: January 2017

Lipoblastoma is a rare neoplasm of embryonal adipose tissue most often encountered on the trunk and extremities of children. It commonly presents as a painless subcutaneous soft tissue mass, but there are other unique clinical presentations that are important to recognize. The differential is broad and includes sarcoma, vascular tumor, myofibroma, and other fibromatoses. We present three varied, distinct cases of pediatric lipoblastoma and review the literature on this condition.
Metabolism of prostaglandin F2alpha in Eurasian lynx (Lynx lynx) and Asian leopard cat (Prionailurus bengalensis euptilura)
Authors: Dehnhard M , Naidenko SV , Jewgenow K
Published: January 2017

Contents

Methods for monitoring endocrine status are useful tools for reproduction management. In particular, successful captive breeding of endangered feline species requires reliable methods for pregnancy diagnosis. In many species, uterine and placental prostaglandin‐F2α (PGF2α) is involved in the regulation of reproductive processes. PGF2α is metabolized to 13,14‐dihydro‐15‐keto‐PGF2a (PGFM) during the first passage through the lungs. Immunoreactive PGFM is elevated in pregnant felids during the last trimester and is used for pregnancy diagnosis, although authentic PGFM is excreted in negligible amounts. To investigate the metabolism of PGF2α, a radiometabolism study was performed in two individuals of two feline species, Eurasian lynx and leopard cats, by injection of tritiated PGF2α and collection of faecal and urinary samples. All samples were extracted and subjected to HPLC separation. Radioactivity and immunoreactivity towards PGFM were determined in each HPLC fraction. The radio‐ and immunogramms differ slightly between the two species, and radiolabelled PGFM was present only in minor amounts. One major eicosanoid metabolite was found in all urine and faecal samples analysed, and also in previous studies in faecal samples of several pregnant feline species. Its polarity was similar, but not identical to PGF2α. We hypothesized that PGF2α is metabolized to more polar dinor and tetranor metabolites. First mass spectrometric analyses favoured a dinor metabolite as major compound of PGF2α metabolism in felids. Following identification and validation in the studied species, we aim to use these metabolites to improve pregnancy detection in other felids and probably other carnivores.
What can we do with 1000 plastid genomes?
Authors: Tonti‐Filippini Julian , Nevill Paul G. , Dixon Kingsley , Small Ian
Published: January 2017

The plastid genome of plants is the smallest and most gene‐rich of the three genomes in each cell and the one generally present in the highest copy number. As a result, obtaining plastid DNA sequence is a particularly cost‐effective way of discovering genetic information about a plant. Until recently, the sequence information gathered in this way was generally limited to small portions of the genome amplified by polymerase chain reaction, but recent advances in sequencing technology have stimulated a substantial rate of increase in the sequencing of complete plastid genomes. Within the last year, the number of complete plastid genomes accessible in public sequence repositories has exceeded 1000. This sudden flood of data raises numerous challenges in data analysis and interpretation, but also offers the keys to potential insights across large swathes of plant biology. We examine what has been learnt so far, what more could be learnt if we look at the data in the right way, and what we might gain from the tens of thousands more genome sequences that will surely arrive in the next few years. The most exciting new discoveries are likely to be made at the interdisciplinary interfaces between molecular biology and ecology.
Programmed death ligand 1 is expressed in canine B cell lymphoma and downregulated by MEK inhibitors
Authors: Kumar S. R. , Kim D. Y. , Henry C. J. , Bryan J. N. , Robinson K. L. , Eaton A. M.
Published: January 2017

Programmed death ligand 1 (PD‐L1) expression in antigen‐presenting cells and tumors can inhibit T cell‐mediated immunity. In this study,
PD‐L1
mRNA and protein expression was evaluated in canine B cell lymphoma (CLL17‐71), large T‐cell leukemia (CLGL‐90), B cell leukemia (GL‐1) and primitive leukocyte round cell neoplasia (CLL‐1390). Variable
PD‐L1
mRNA and protein were observed in these cells with high endogenous expression present in CLL17‐71 cells. PD‐L1 protein was also observed in canine patient B cell lymphoma tissues using immunostaining.
PD‐L1
and signal transducer and activator of transcription 1 (
STAT1
) mRNA expression were reduced in the presence of mitogen‐activated protein kinase kinase 1.2 (MEK1/2) inhibitors RDEA119 and AZD6244 in CLL 17‐71 cells. RDEA119 had similar effect on
PD‐L1
and
STAT‐1 in IFN‐γ activated CLL‐1390 cells. Overall, these results indicate that PD‐L1 is expressed in canine B cell lymphoma. Its inhibition by MEK1/2 inhibitors suggests a possible treatment strategy using targeted drugs which likely could enhance antitumor immune response.
Paraboline variation over -adic families of -modules
Authors: Bergdall John
Published: January 2017

We study the$p$-adic variation of triangulations over$p$-adic families of$(\unicode[STIX]{x1D711},\unicode[STIX]{x1D6E4})$-modules. In particular, we study certain canonical sub-filtrations of the pointwise triangulations and show that they extend to affinoid neighborhoods of crystalline points. This generalizes results of Kedlaya, Pottharst and Xiao and (independently) Liu in the case where one expects the entire triangulation to extend. We also study the ramification of weight parameters over natural$p$-adic families.
Análisis del desarrollo institucional desde el enfoque institucional histórico
Authors: Saavedra Echeverry Saúl
Published: January 2017

En el estudio del desarrollo de las instituciones políticas, los académicos que hoy trabajan con el enfoque institucionalista histórico vienen intro-duciendo en sus marcos de análisis conceptos, tales como el tiempo, los contextos, las coali-ciones políticas y las ideas. Su interés es tratar de conectarlos en estudios de caso, que tienen como objeto comprender y explicar la estabilidad y el cambio en la vida política. Estas dos últimas dimensiones no las conciben separadas del desarrollo institucional, pues los mecanismos que propician la estabilidad son los mismos que generan el cambio. Las indagaciones que se inspiran en las principales ideas fuerza del institucionalismo histórico pueden enriquecerse con los aportes del institucionalismo discursivo, novedoso programa de investigación institu-cionalista que subraya la influencia de las ideas (el discurso y la comunicación) en el desarrollo institucional. Para el institucionalismo discursi-vo, las instituciones cambian por el efecto de las ideas, tanto por el contenido sustantivo de estas como por el proceso interactivo del discurso. La coordinación política, la comunicación y la deli-beración que acompañan a la actividad pública tienen una dimensión discursiva
Racionalidad del modelo de desarrollo chino: una perspectiva institucionalista
Authors: Gálvez Rubio Tatiana , Defelipe Villa Camilo
Published: January 2017

El modelo de economía de mercado con ca-racterísticas chinas ha consolidado libertades para el desarrollo de la actividad económica y mayores niveles de ingreso para la población; sin embargo, algunas prácticas económicas todavía se desarrollan de acuerdo con lógicas de planifi-cación centralizada contrarias a los principios de eficiencia y premio económico que distorsionan las decisiones económicas de los agentes. El presente artículo pretende analizar la raciona-lidad del modelo económico chino a la luz del concepto de racionalidad cognitiva del enfoque institucionalista, y para ello se abordarán aspec-tos como los derechos de propiedad de la tierra y la corrupción. Se concluye que para el caso chino las prácticas, como el guanxi y el mianzi prevalecen como determinantes de la conducta económica y social de los ciudadanos, a pesar de la existencia de códigos legales contradictorios frente a dichas prácticas.
La violencia en el Triángulo Norte de Centroamérica: una realidad que genera desplazamiento
Authors: Jiménez Everardo Víctor
Published: January 2017

El trabajo que aquí se presenta, basado en una revisión de la literatura de lo que se ha producido en los últimos años, trata el fenómeno de la violencia en el Triángulo Norte de Centroamérica como un generador de desplazamiento forzado de la población. En primer lugar, según varios autores, se establecerán criterios válidos, con el fin de construir un concepto más amplio y más claro de la violencia, que a su vez permite la captura de todas las dimensiones de su manifestación en la región centroamericana. Los factores que fomentan esta violencia serán considerados más adelante, en relación con aspectos sociales, culturales o políticos. En toda esta alarmante ola de violencia, algunos de los actores principales son notorios, por ejemplo bandas como las maras y traficantes de droga. La violencia generada por estos actores, junto con la violencia estructural soportada por las sociedades centroamericanas del Triángulo del Norte, provoca el desplazamiento de la población. Por tanto, es imperativo encontrar soluciones para hacer frente a esta realidad que está creando tal expulsión de la población, que trata de escapar de la violencia y está a menudo indefensa frente a ella.
Atención centrada en el paciente y la familia en la Unidad de Cuidado Intensivo Pediátrico del hospital Pablo Tobón Uribe, sistematización de la experiencia
Authors: Torres-Ospina Julio Nicolás , Vanegas-Díaz César Augusto , Yepes-Delgado Carlos Enrique
Published: January 2017

Ante las frías relaciones que se suelen establecer en las unidades de cuidado intensivo pediátricas (UCIP), entre el personal de salud y las familias de los menores internados, algunos médicos del hospital Pablo Tobón Uribe, al buscar mejorar la comunicación, desarrollaron una estrategia que propició el diálogo y la escucha asertiva, luego de poner en práctica el modelo de “Atención Centrada en el Paciente y la Familia”. La metodología de sistematización de experiencias permitió un análisis reflexivo de los testimonios recogidos en los múltiples encuentros entre personal de salud y 820 familiares. Los resultados, en términos de aprendizajes, permitieron evidenciar una atención integral que involucró a la familia como sujeto de cuidado, concienció sobre la repercusión psicológica que implica la experiencia de permanencia en la UCIP y estimuló una reflexión crítica del equipo de salud en la atención ofrecida a las familias de los pacientes en la práctica clínica diaria.
Atención médica y diferencia cultural. Acceso a atención médica de mujeres musulmanas en Bogotá
Authors: Arboleda-Sarmiento Juan Camilo , Suárez-Montañez Roberto
Published: January 2017

Desde 1991 Colombia se define constitucionalmente como un país multicultural. Sin embargo, la aplicación de esta definición es aún incierta. Sobre esta base, el texto explora la relación entre diversidad cultural y acceso a servicios de salud, a partir del caso de las mujeres musulmanas en la ciudad de Bogotá, Colombia. Se plantea cómo los estilos de vida, el género y los sistemas de creencias afectan las trayectorias de cuidado y el encuentro terapéutico de personas definidas como musulmanes en los servicios de atención médica. Se desarrolló un trabajo de corte cualitativo, donde se articulan la salud pública y la antropología médica. Se encontró que el acceso a la atención médica de las mujeres musulmanas está mediado por interacciones sociales que facilitan los desencuentros médicos. De allí que la promoción de la salud y la prevención de la enfermedad requieran la comprensión e integración de la cultura como categoría mediadora en la salud pública.

 
Ahorro del sistema de salud por la regulación directa de precios de venta de medicamentos biotecnológicos en Colombia
Authors: Sánchez-Villalobos Oswaldo , Mesa-Escobar Giovanni Humberto , Ruíz-Correa Andrés Felipe , Quintero-Ortiz Diego Nadin , López Sandy Lorena , Serna-Guerrero Juan Sebastián , Muñoz-Díaz Paola Andrea
Published: January 2017

Se desarrolló un análisis retrospectivo sobre las ventas de trece biotecnológicos regulados, entre junio del 2010 y junio del 2014, en dos escenarios: valores facturados después de la regulación de precios y valores supuestos, calculados a partir del precio de venta promedio de los seis meses anteriores a la regulación, más el índice de precios al consumidor en salud. La diferencia entre ambos escenarios supone un ahorro al sistema. Los biotecnológicos analizados generaron un ahorro de USD $95 000 000 en dicho periodo; en el primer año el 10.2 %, el segundo año el 17.2 % y en el tercero el 30.5 %. El biotecnológico que más ahorro representó fue el rituximab (40,9 %), equivalente a USD $38 510 787. La regulación directa de precios de medicamentos biotecnológicos le ha generado ahorros significativos al sistema de salud, visto desde las ventas registradas en Audifarma. Probablemente, el ahorro económico que ha generado esta política es superior a lo estimado inicialmente por el Gobierno..
Leakage Degradation of Straight Labyrinth Seal Due to Wear of Round Tooth Tip and Acute Trapezoidal Rub-Groove
Authors: Dogu Yahya , Sertçakan Mustafa C. , Gezer Koray , Kocagül Mustafa , Arıcan Ercan , Ozmusul Murat S.
Published: January 2017

In this paper, labyrinth seal leakage is numerically quantified for an acute trapezoidal rub-groove accompanied with a rounded tooth, as a function of rub-groove sizes and tooth-groove axial positions. Analyses parameters include clearance, pressure ratio, number of teeth, and rotor speed. Labyrinth seals wear during engine transients. Radial incursion and axial movement of the rotor–stator pair cause the labyrinth teeth to rub against the unworn stator surface. The labyrinth teeth and/or stator wear depending on their material hardness. Wear damage in the form of material loss or deformation permanently increases seal clearance, and thus, leakage. This leakage is known to be dependent on the shape and geometry of the worn tooth and the stator rub groove. There are two types of reported tooth tip wear. These can be approximated as a mushroom shape and a round shape. The stator rub-groove shapes can be approximately simulated in five forms: rectangle, trapezoid (isosceles and acute), triangle, and ellipse. In this paper, the acute trapezoidal rub-groove shape is specifically chosen, since it is the most similar to the most commonly observed rub-groove form. The tooth tip is considered to be rounded, because the tooth tip wears smoothly and a round shape forms during rub-groove formation. To compare the unworn tooth, the flat stator is also analyzed as a reference case. All analyzed parameters for geometric dimensions (groove width, depth, wall angle, and tooth-groove axial position) and operating conditions (flow direction, clearance, pressure ratio, number of teeth, and rotor speed) are analyzed in their practical ranges. Computational fluid dynamics (CFD) analyses are carried out by employing a compressible turbulent flow solver in a 2D axisymmetrical coordinate system. CFD analyses show that the rounded tooth leaks more than an unworn sharp-edged tooth, due to the formation of a smooth and streamlined flow around the rounded geometry. This smooth flow yields less flow separation, flow disturbance, and less of vena contracta effect. The geometric dimensions of the acute trapezoidal rub-groove (width, depth, wall angle) significantly affect leakage. The effects of clearance, pressure ratio, number of teeth, and rotor speed on the leakage are also quantified. Analyses results are separately evaluated for each parameter.
Stability of the Size-Dependent and Functionally Graded Curvilinear Timoshenko Beams
Authors: Awrejcewicz J. , Krysko A. V. , Pavlov S. P. , Zhigalov M. V. , Krysko V. A.
Published: January 2017

The size-dependent model is studied based on the modified couple stress theory for the geometrically nonlinear curvilinear Timoshenko beam made from a functionally graded material having its properties changed along the beam thickness. The influence of the size-dependent coefficient and the material grading on the stability of the curvilinear beams is investigated with the use of the setup method. The second-order accuracy finite difference method is used to solve the problem of nonlinear partial differential equations (PDEs) by reducing it to the Cauchy problem. The obtained set of nonlinear ordinary differential equations (ODEs) is then solved by the fourth-order Runge–Kutta method. The relaxation method is employed to solve numerous static problems based on the dynamic approach. Eight different combinations of size-dependent coefficients and the functionally graded material coefficient are used to study the stress-strain responses of Timoshenko beams. Stability loss of the curvilinear Timoshenko beams is investigated using the Lyapunov criterion based on the estimation of the Lyapunov exponents. Beams with/without the size-dependent behavior, homogeneous beams, and functionally graded beams having the same stiffness are investigated. It is shown that in straight-line beams, the size-dependent effect decreases the beam deflection. The same is observed if the most rigid layer is located on the top of the beam. In the curvilinear Timoshenko beam, such a location of the most rigid layer essentially improves the beam strength against stability loss. The observed transition of the largest Lyapunov exponent from a negative to positive value corresponds to the transition from a precritical to postcritical beam state.
Evaluation of Scanning Parameters Based on Image Entropy for Dimensional Computed Tomography Metrology
Authors: Xue Lin , Suzuki Hiromasa
Published: January 2017

Many types of artifacts appear in X-ray computed tomography (CT) volume data, which influence measurement quality of industrial cone beam X-ray CT. Most of those artifacts are associated to CT scanning parameters; therefore, a good scanning parameter setting can weaken the influence to improve measurement accuracy. This paper presents a simulation method for evaluating CT scanning parameters for dimensional metrology. The method can aid CT metrology to achieve high measurement accuracy. In the method, image entropy is used as a criterion to evaluate the quality of CT volume data. For entropy calculation of CT volume data, a detailed description about bin width and entropy zone is given. The relationship between entropy values of CT volume data and error parameters of CT metrology is shown and discussed. By use of this method, mainly we focus on specimen orientation evaluation, and some other typical scanning parameters are used to evaluate the proposed method. Two typical specimens are used to evaluate the performance of the proposed method.
Local Analysis of Helicoid–Helicoid Intersections in Reconfigurable Linkages
Authors: López-Custodio P. C. , Rico J. M. , Cervantes-Sánchez J. J.
Published: January 2017

Kinematic chains are obtained from the helicoid–helicoid intersections applying the method of surfaces generated by kinematic dyads. Some local properties of the helicoids are used to obtain the bifurcation points in the configuration space of the obtained kinematic chains. It is proven that certain relationships between the two helicoids lead to a periodic behavior of these bifurcations, which suggest that, if the kinematic pairs (P and H) could move without a limit, the kinematic chain would theoretically feature an infinity of operation modes. Finally, a mechanism which is able to change the helicoid–helicoid intersection curve during its motion is proven to change its finite mobility in one of its operation modes.
Design and Static Analysis of Elastic Force and Torque Limiting Devices for Safe Physical Human–Robot Interaction
Authors: Zhang Meiying , Laliberté Thierry , Gosselin Clément
Published: January 2017

This paper presents the static analysis of elastic force and torque limiters that aim at limiting the forces that a robotic manipulator can apply on its environment. First, the design of one-degree-of-freedom force and torque limiting mechanisms is presented. It is shown that a single elastic component (spring) can be used to provide a prescribed preload and stiffness in both directions of motion along a given axis. Then, the mechanisms are analyzed in order to determine the nonlinear relationships between the motion of the mechanism and the extension of the spring. These relationships can then be used in the design of the force and torque limiters. Finally, the force capabilities of the mechanisms are investigated and numerical results are provided for example designs.
Force-Controlled Exploration for Updating Virtual Fixture Geometry in Model-Mediated Telemanipulation
Authors: Wang Long , Chen Zihan , Chalasani Preetham , Yasin Rashid M. , Kazanzides Peter , Taylor Russell H. , Simaan Nabil
Published: January 2017

This paper proposes an approach for using force-controlled exploration data to update and register an a priori virtual fixture geometry to a corresponding deformed and displaced physical environment. An approach for safe exploration implementing hybrid motion/force control is presented on the slave robot side. During exploration, the shape and the local surface normals of the environment are estimated and saved in an exploration data set. The geometric data collected during this exploration scan are used to deform and register the a priori environment model to the exploration data set. The environment registration is achieved using a deformable registration based on the coherent point drift method. The task-description of the high-level assistive telemanipulation law, called a virtual fixture (VF), is then deformed and registered in the new environment. The new model is updated and used within a model-mediated telemanipulation framework. The approach is experimentally validated using a da-Vinci research kit (dVRK) master interface, a dVRK patient side manipulator, and a Cartesian stage robot. Experiments demonstrate that the updated VF and the updated model allow the users to improve their path following performance and to shorten their completion time when the updated path following VF is applied. The approach presented has direct bearing on a multitude of surgical applications including force-controlled ablation.
Robotic Modular Leg: Design, Analysis, and Experimentation
Authors: Saab Wael , Rone William S. , Ben-Tzvi Pinhas
Published: January 2017

This paper presents the design and analysis of a reduced degree-of-freedom (DOF) robotic modular leg (RML) mechanism. The RML is composed of a two serially connected four-bar mechanisms that utilize mechanical constraints between articulations to maintain a parallel orientation between the foot and body without the use of an actuated ankle. Kinematic and dynamic models are developed for the leg mechanism and used to analyze actuation requirements and aid motor selection. Experimental results of an integrated prototype tracking a desired foot trajectory are analyzed to improve the accuracy and repeatability of the mechanism. The prototype weighs 4.7 kg and measures 368 mm in a fully extended configuration and exhibits a maximum deviation from the straight line support phase equivalent to 5.2 mm.
Hemodynamic Profile of Two Aortic Endografts Accounting for Their Postimplantation Position
Authors: Raptis Anastasios , Xenos Michalis , Georgakarakos Efstratios , Kouvelos George , Giannoukas Athanasios , Matsagkas Miltiadis
Published: January 2017

Endovascular aneurysm repair (EVAR) is a clinically effective technique for treating anatomically eligible abdominal aortic aneurysms (AAAs), involving the deployment of an endograft (EG) that is designed to prevent blood leakage in the aneurysmal sac. While most EGs have equivalent operating principles, the hemodynamic environment established by different EGs is not necessarily the same. So, to unveil the post-EVAR hemodynamic properties, we need an EG-specific computational approach that currently lacks from the literature. Endurant and Excluder are two EGs with similar pre-installation designs. We assumed that the flow conditions in the particular EGs do not vary significantly. The hypothesis was tested combining image reconstructions, computational fluid dynamics (CFD), and statistics, taking into account the postimplantation position of the EGs. Ten patients with Endurant EGs and ten patients with Excluder EGs were included in this study. The two groups were matched with respect to the preoperative morphological characteristics of the AAAs. The EG models are derived from image reconstructions of postoperative computed tomography scans. Wall shear stress (WSS), displacement force, velocity, and helicity were calculated in regions of interest within the EG structures, i.e., the main body, the upper and lower part of the limbs. Excluder generated higher WSS compared to Endurant, especially on the lower part of the limbs (p = 0.001). Spatial fluctuations of WSS were observed on the upper part of the Excluder limbs. Higher blood velocity was induced by Excluder in all the regions of interest (p = 0.04, p = 0.01, and p = 0.004). Focal points of secondary flow were detected in the main body of Endurant and the limbs of Excluder. The displacement force acting on the lower part of the Excluder limbs was stronger compared to the Endurant one (p = 0.03). The results showed that two similar EGs implanted in similar AAAs can induce significantly different flow properties. The delineation of the hemodynamic features associated with the various commercially available EGs could further promote the personalization of treatment offered to aneurysmal patients and inspire ideas for the improvement of EG designs in the future.
Strain Growth in a Finite-Length Cylindrical Shell Under Internal Pressure Pulse
Authors: Dong Qi , Li Q. M. , Zheng Jinyang
Published: January 2017

Strain growth is a phenomenon observed in the elastic response of containment vessels subjected to internal blast loading. The local dynamic response of a containment vessel may become larger in a later stage than its response in the earlier stage. In order to understand the possible mechanisms of the strain growth phenomenon in a cylindrical vessel, dynamic elastic responses of a finite-length cylindrical shell with different boundary conditions subjected to internal pressure pulse are studied by finite-element simulation using LS-DYNA. It is found that the strain growth in a finite-length cylindrical shell with sliding–sliding boundary conditions is caused by nonlinear modal coupling. Strain growth in a finite-length cylindrical shell with free–free or simply supported boundary conditions is primarily caused by the linear modal superposition, possibly enhanced by the nonlinear modal coupling. The understanding of these strain growth mechanisms can guide the design of cylindrical containment vessels.
Heat Transfer Enhancement in Turbulent Ribbed-Pipe Flow
Authors: Kang Changwoo , Yang Kyung-Soo
Published: January 2017

The present study aims at explaining why heat transfer is enhanced in turbulent ribbed-pipe flow, based on our previous large eddy simulation (LES) database (Kang and Yang, 2016, “Characterization of Turbulent Heat Transfer in Ribbed Pipe Flow,” ASME J. Heat Transfer, 138(4), p. 041901) obtained for Re = 24,000, Pr = 0.71, pitch ratio (PR) = 2, 4, 6, 8, 10, and 18, and blockage ratio (BR) = 0.0625. Here, the bulk velocity and the pipe diameter were used as the velocity and length scales, respectively. The ribs were implemented in the cylindrical coordinate system by means of an immersed boundary method. In particular, we focus on the cases of PR ≥ 4 for which heat transfer turns out to be significantly enhanced. Instantaneous flow fields reveal that the vortices shed from the ribs are entrained into the main recirculating region behind the ribs, inducing velocity fluctuations in the vicinity of the pipe wall. In order to identify the turbulence structures responsible for heat transfer enhancement in turbulent ribbed-pipe flow, various correlations among the fluctuations of temperature and velocity components have been computed and analyzed. The cross-correlation coefficient and joint probability density distributions of velocity and temperature fluctuations, obtained for PR = 10, confirm that temperature fluctuation is highly correlated with velocity-component fluctuation, but which component depends upon the axial location of interest between two neighboring ribs. Furthermore, it was found via the octant analysis performed for the same PR that at the axial point of the maximum heat transfer rate, O3 (cold wallward interaction) and O5 (hot outward interaction) events most contribute to turbulent heat flux and most frequently occur.
Two Methods to Broaden the Bandwidth of a Nonlinear Piezoelectric Bimorph Power Harvester
Authors: Hu Hongping , Dai Longxiang , Chen Hao , Jiang Shan , Wang Hairen , Laude Vincent
Published: January 2017

We propose two methods to broaden the operation bandwidth of a nonlinear pinned–pinned piezoelectric bimorph power harvester. The energy-scavenging structure consists of a properly poled and electroded flexible bimorph with a metallic layer in the middle, and is subjected to flexural vibration. Nonlinear effects at large deformations near resonance are considered by taking the in-plane extension of the bimorph into account. The resulting output powers are multivalued and exhibit jump phenomena. Two methods to broaden the operation bandwidth are proposed: The first method is to extend the operation frequency to the left single-valued region through optimal design. The second method is to excite optimal initial conditions with a voltage source. Larger output powers in the multivalued region of the nonlinear harvester are obtained. Hence, the operation bandwidth is broadened from the left single-valued region to the whole multivalued region.
Cloud-Based Augmented Reality Remote Maintenance Through Shop-Floor Monitoring: A Product-Service System Approach
Authors: Mourtzis Dimitris , Vlachou Aikaterini , Zogopoulos Vasilios
Published: January 2017

Maintenance and its cost continue, over the years, drawing the attention of production management, since the unplanned failures decrease the reliability of the system and the return of investments. Maintenance services of manufactured products are among the most common services in the industry; they account for more than half of the total costs and influence the environmental impact of the product. In order for manufacturers to increase their productivity, by performing accurate and quick maintenance, advanced monitoring systems should be considered in order to easily detect machine tool failures before they occur. Toward that end, a cloud-based platform for condition-based preventive maintenance, supported by a shop-floor monitoring service and an augmented reality (AR) application, is proposed as a product-service system (CARM2-PSS). The proposed AR maintenance service consists of algorithms of automated generation of assembly sequences, part movement scripts, and improved interface that aim to maximize existing knowledge usage while creating vivid AR service instructions. Moreover, the proposed monitoring system is supported by a wireless sensor network (WSN), and is deployed on a Cloud environment together with the AR tool. The monitoring system monitors the status of the machine tools, calculates their remaining operating time between failures (ROTBF), and identifies the available windows of the machine tools in order to perform the AR remote maintenance. In order to validate the proposed methodology and calculate its impact, it is applied in a real-life case study of a white-goods industry.
Experimental Study of Process Emissions From Atomic Layer Deposition of Al2O3 Under Various Temperatures and Purge Time
Authors: Ma Lulu , Pan Dongqing , Xie Yuanyuan , Wang Fenfen , Yuan Chris
Published: January 2017

Experimental investigations of process emissions from atomic layer deposition (ALD) of Al2O3 are accomplished under various temperatures and purge times to understand its environmental sustainability performance. About 93% of Trimethylaluminum (TMA) is found flowing through ALD system without deposition. 2–9 × 104 of ultrafine nanoparticles containing 51.9 ± 4.6% of C, 16.6 ± 0.9% of Al, 31.4 ± 4.1% of O are generated during each cycle of reactions. 0.34–0.38 cm3 of CH4 (25 °C, 1 atm), which takes up 45–51% of C contained in TMA is produced simultaneously. The concentration of nanoparticles drops with the increase of purge time. CH4 also has a trend of decreasing but acts more complex with the largest emission at a short purge time. Compared with temperature, which has limited effects on reactants, purge time changes the time of reaction as well as the degree of gas phase mixing, and therefore greatly influences ALD emissions.
Doping Effect of Alkaline Earth Metal on Oxygen Reduction Reaction in Praseodymium Nickelate With Layered Perovskite Structure
Authors: Wei Lai , Sun Li-Ping , Li Qiang , Huo Li-Hua , Zhao Hui
Published: January 2017

Pr1.9A0.1NiO4 (A = Ca, Sr, Ba) are synthesized and characterized by X-ray powder diffraction (XRD), infrared spectrum (IR), and X-ray photoelectron spectroscopy (XPS). The effects of alkaline earth doping on the covalence of Pr–O and Ni–O bond, the mean valence of Ni, and the hydroxide absorption ability of material surface are studied. It is found that the covalence of Pr–O and Ni–O bond increases with the decrease of alkaline earth element radius. Meanwhile, the mean valence of Ni and the surface hydroxide absorption ability are enhanced. The electrochemical measurement results indicate that the O2−2 /OH− replacement reaction is facilitated by the increase of mean valence of Ni in the material. The best oxygen reduction reaction (ORR) activity is found in Pr1.9Ca0.1NiO4. The current density of 2.16 mA cm−2 is obtained at a potential of −0.6 V (versus Hg/HgO). The tafel slope is 66.48 mV decade−1, close to Pt/C material.
Effective Spectral Emissivity of Gas Turbine Blades for Optical Pyrometry
Authors: Tian Jibin , Fu Tairan , Xu Qiaoqi , Jiang Hongde
Published: January 2017

Turbine blade temperature measurements are important for monitoring the turbine engine performance to protect the hot components from damage due to excess temperatures. However, the reflected radiation from the blades and the surrounding environment complicate the blade temperature measurements by optical pyrometers. This study characterizes the effect of the reflected radiation on the effective spectral emissivity of a three-dimensional turbine blade in a confined turbine space for optical pyrometry temperature measurements. The effective spectral emissivity distribution on a three-dimensional blade was numerically determined for various wavelengths (0.8–15.0 μm) and actual blade surface emissivities for a specified turbine blade model. When the actual spectral emissivity of the blade surface is assumed to be 0.5, the effective spectral emissivity varies from 0.5 to 0.538 at the longer wavelength of 10.0 μm and further increases from 0.5 to 1.396 at the shorter wavelength of 0.9 μm. The results show that the effective emissivity distributions at shorter wavelengths differ greatly from those at longer wavelengths. There are also obvious differences between the effective spectral emissivity and the actual surface emissivity at shorter wavelengths. The effect of the effective emissivity on the temperature measurement accuracy, when using the optical pyrometry, was also investigated for various wavelengths (0.8–15.0 μm). The results show that the radiation reflected from the blades has less effect on the temperature measurements than on the effective emissivity, especially at the shorter wavelengths of 0.8–3.0 μm. However, the temperature measurements still need to be corrected using the effective spectral emissivity to improve the temperature calculation accuracy. This analysis provides guidelines for choosing the optimum measurement wavelengths for optical pyrometry in turbine engines.
Experimental and Computational Analysis of the Swirling Flow Generated by an Axial Counter-Rotating Swirler in a Rectangular Model Chamber Using Water Test Rig
Authors: Vashahi Foad , Lee Sangho , Lee Jeekeun
Published: January 2017

This paper reports the particle image velocimetry (PIV) measurement of swirling flow in a confined rectangular-shaped model combustion chamber. Water is used as the working fluid, and the average profiles of axial, radial, and magnitudes of velocity are given. Flow behavior is investigated and a rebound angle term is defined to investigate the direct effects of the noncircular chamber shape. Flow behavior near the walls is discussed in detail, as are other important swirling flow features such as the appearance of corner and central toroidal recirculation zones. Additionally, experimental data are compared with simulation results. Analyses were performed via commercial software STAR-CCM+ version 9.0. The large eddy simulation (LES) dynamic Smagorinsky subgrid scale, realizable k–ε model, and k–ω shear-stress transport (SST) detached eddy version were used as simulation tools. Three different test filters of 1.0, 2.2, and 3.0 were applied to the LES to identify improvements in accuracy. The overall best turbulence model is compared to the experimental result and reliability of such model is evaluated. The ability of such model was profound within the upstream and to some extent unreliable in downstream.
Modeling and Simulation of an Inverted Brayton Cycle as an Exhaust-Gas Heat-Recovery System
Authors: Chen Zhihang , Copeland Colin , Ceen Bob , Jones Simon , Agurto Goya Alan
Published: January 2017

The exhaust gas from an internal combustion engine contains approximately 30% of the thermal energy of combustion. The exhaust-gas heat-recovery systems aim to reclaim a proportion of this energy in a bottoming thermodynamic cycle to raise the overall system thermal efficiency. The inverted Brayton cycle (IBC) considered as a potential exhaust-gas heat-recovery system is a little-studied approach, especially when applied to small automotive power-plants. Hence, a model of the inverted Brayton cycle using finite-time thermodynamics (FTT) is presented to study heat recovery applied to a highly downsizing automotive internal combustion engine. IBC system consists of a turbine, a heat exchanger (HE), and compressors in sequence. The use of IBC turbine is to fully expand the exhaust gas available from the upper cycle. The remaining heat in the exhaust after expansion is rejected by the downstream heat exchanger. Then, the cooled exhaust gases are compressed back up to the ambient pressure by one or more compressors. In this paper, the exhaust conditions available from the engine test bench data were introduced as the inlet conditions of the IBC thermodynamic model to quantify the power recovered by IBC, thereby revealing the benefits of IBC to this particular engine. It should be noted that the test bench data of the baseline engine were collected by the worldwide harmonized light vehicles test procedures (WLTP). WLTP define a global harmonized standard for determining the levels of pollutants and CO2 emissions, fuel consumption. The IBC thermodynamic model was simulated with the following variables: IBC inlet pressure, turbine pressure ratio, heat exchanger effectiveness, turbomachinery efficiencies, and the IBC compression stage. The aim of this paper is to analysis the performance of IBC system when it is applied to a light-duty automotive engine operating in a real-world driving cycle.
An Embedded System for a High-Speed Manipulator With Single Time Scale Visual Servoing
Authors: Liyanage Migara H. , Krouglicof Nicholas
Published: January 2017

This study presents the development of an embedded system for controlling a high-speed robotic manipulator. Three different types of controllers including hardware proportional derivative (PD), software PD, and single time scale visual servoing are considered in this study. Novel field programmable gate array (FPGA) technology was used for implementing the embedded system for faster execution speeds and parallelism. It is comprised of dedicated hardware and software modules for obtaining sensor feedback and control signal (CT) estimation, providing the control signal to the servovalves. A NIOS II virtual soft processor system was configured in the FPGA for implementing functions that are computationally expensive and difficult to implement in hardware. Quadrature decoding, serial peripheral interface (SPI) input and output modules, and control signal estimation in some cases was carried out using the dedicated hardware modules. The experiments show that the proposed controller performed satisfactory control of the end effector position. It performed single time scale visual servoing with control signal updates at 330 Hz to control the end effector trajectory at speeds of up to 0.8 ms−1. The FPGA technology also provided a more compact single chip implementation of the controller.
Improving Lithium-Ion Battery Pack Diagnostics by Optimizing the Internal Allocation of Demand Current for Parameter Identifiability
Authors: Rothenberger Michael J. , Safi Jariullah , Liu Ji , Anstrom Joel , Brennan Sean , Fathy Hosam K.
Published: January 2017

This article optimizes the allocation of external current demand among parallel strings of cells in a lithium-ion battery pack to improve Fisher identifiability for these strings. The article is motivated by the fact that better battery parameter identifiability can enable the more accurate detection of unhealthy outlier cells. This is critical for pack diagnostics. The literature shows that it is possible to optimize the cycling of a single battery cell for identifiability, thereby improving the speed and accuracy with which its health-related parameters can be estimated. However, the applicability of this idea to online pack management is limited by the fact that overall pack current is typically dictated by the user, and difficult to optimize. We circumvent this challenge by optimizing the internal allocation of total pack current for identifiability. We perform this optimization for two pack designs: one that exploits switching control to allocate current passively among parallel strings of cells, and one that incorporates bidirectional DC–DC conversion for active charge shuttling among the strings. A novel evolutionary algorithm optimizes identifiability for each pack design, and a local outlier probability (LoOP) algorithm is then used for diagnostics. Simulation studies show significant improvements in diagnostic accuracy for an automotive protocol.
A Preliminary Investigation Into the Characterization of Asphaltenes Extracted From an Oil Sand and Two Vacuum Residues From Petroleum Refining Using Nuclear Magnetic Resonance, DEPT, and MALDI-TOF
Authors: Zheng Ce , Zhu Mingming , Zhou Wenxu , Zhang Dongke
Published: January 2017

This paper reports the findings of an investigation into the molecular structures and properties of three asphaltene samples, namely, an asphaltene sample extracted from Buton Oil Sand (Indonesia), and two asphaltene samples extracted from vacuum residues from Liaohe Refinery (China) and Vene Refinery (Venezuela), respectively. The average molecular structural parameters, including the average polycyclic aromatic hydrocarbon (PAH) size, average side chain length, and average molecular weight (AMW), of the three asphaltene samples were estimated using data from nuclear magnetic resonance (NMR) in combination with distortionless enhancement by polarization transfer (DEPT), and then compared against each other. The molecular weight distributions (MWDs) of the three asphaltene samples were measured using a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The results indicated that the island molecular architecture predominated in all three asphaltenes and the average polycyclic aromatic hydrocarbon size was found to be six rings. The average molecular weight of the Buton asphaltene sample was found to be ca. 800 Da while those of the two petroleum asphaltene samples were approximately 600 Da. In comparison, the Buton asphaltene sample contained a much higher level of oxygen and sulfur, but a lower aromaticity than those of the two petroleum asphaltene samples. The use of liquid NMR in combination with DEPT was shown to provide an effective method for characterization and estimation of the molecular structures of asphaltenes, supported by MALDI-TOF mass spectra.
Design and Experimental Study of a Cascade Thermoacoustic Engine for Remote and Rural Communities
Authors: Dhuchakallaya Isares , Saechan Patcharin
Published: January 2017

The design, construction, and experimental evaluation of a cascade thermoacoustic engine are presented in this paper. The system was designed and built under the constraint of an inexpensive device to meet the energy needs of the people based in remote and rural areas. From the cost and straightforward system point of view, the air at atmospheric pressure was applied as a working fluid, and the main resonator tubes were then constructed of conventional polyvinyl chloride (PVC) pipes. Such device consists of one standing-wave unit and one traveling-wave unit connected in series. This topology is preferred because the traveling-wave unit provides an efficient energy conversion, and a straight-line series configuration is easy to build and allows no Gedeon streaming. The system was designed to operate at a low frequency of about 57 Hz. The measured results were in a reasonably good agreement with the predicted results. So far, this system can deliver up to 61 W of acoustic power, which was about 17% of the Carnot efficiency. In the further step, the proposed device will be applied as the prime mover for driving the thermoacoustic refrigerator.