bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the Influence of Non-sinusoidal Conditions on Power Transformers
Authors: Kovernikova Lidiia , Van Cuong Ngo
Published: October 2018

The electrical equipment operation is cost-effective and reliable when operating parameters of the electrical network correspond to the rated data of the equipment. The real operation conditions, however, differ from those required for electrical equipment, which negatively affects its efficiency. The non-sinusoidal conditions in electrical networks are currently very common. The paper provides an overview of the characteristics obtained from an analysis of publications, which are used to evaluate the effect of the non-sinusoidal conditions on power transformers. The results of the calculation of these characteristics for a transformer installed at a railway traction substation are presented. Parameters of the non-sinusoidal conditions are obtained as a result of measurements.
Effect of asymmetry of supply voltages on asynchronous motor operation modes
Authors: Romanova Victoria , Khromov Sergey
Published: October 2018

Effect of asymmetry of supply voltages on asynchronous motor operation modes was investigated using the computer-aided simulation experiments, the software complex Matlab and the package program Simulink. Publication relevance is determined by the necessity for performance of comparative analysis of the level of effect of asymmetry of supply voltages on asynchronous motors of different series and power capacities. Six motors of three different power capacities (5.5, 55, 160 kW) and of two different series (4A, AI) were modeled for investigation. The value of asymmetry of supply voltages was changed from 0 to 5%. The motor shaft load was changed from 0 to 120% of the motor rated load. Comparison of dependencies of the phase currents on the voltage unbalance ratio by reverse sequence (K2U) of asynchronous motors with short-circuited rotor series 4A and AI was made. The analysis and discussion of obtained investigation results were performed, recommendations on operation of asynchronous motors series 4A and AI in conditions of asymmetry of supply voltages were given.
Modeling of three-phase electric motor operation by the MATLAB system with deteriorated power quality in the 0.38 kV distribution networks
Authors: Naumov I.V , Savina N.V. , Shevchenko M.V.
Published: October 2018

One of the main operation modes that characterizes power quality in distribution networks is asymmetry of three-phase voltage system. Operation of an induction motor (IM) with disturbed voltage symmetry in the supply network can not be considered as a rated one. The system of voltages applied to the stator winding of IM under these conditions contains positive- and negative-sequence components. This worsens the performance characteristics of IM essentially. In order to balance the 0.38 kV network operation and enhance the efficiency of the three-phase electric motor operation it is suggested to use a special balancing unit (BU) that minimizes the negative-sequence components of current and voltage. The operation modes of the obtained system “supply source – induction motor – balancing unit” are simulated within the MATLAB software package of applied programs, which allows one to assess the impact of low quality of power on the operating characteristics of the electric motor and the efficiency of the balancing unit to increase the “durability” of the motor under the asymmetrical power consumption.
Complex dynamics of drill-strings: Theory and experiments
Authors: Wiercigroch Marian , Kapitaniak Marcin , Vaziri Vahid , Nandakumar Krishnan
Published: October 2018

We investigate complex drill-string dynamics in a downhole drilling where strong nonlinear interactions between various types of vibration take place. First, we present a low dimensional model of the downhole drilling where a drill-bit cutting a rock formation has a strong coupling between torsional and axial oscillations. The model can be used to study drilling stability as an example results are given. Then we introduce a new experimental rig developed by the Centre for Applied Dynamics Research at the University of Aberdeen, capable of reproducing all major types of drill-string vibration. One of the most important features of this versatile experimental rig is the fact that commercial drill-bits, employed in the drilling industry, and real rock-samples are used. The rig operate in different configurations, which enables the experimental study of various phenomena, such as stick-slip oscillations, whirling and drill-bit bounce. It also allows to determine mechanical characteristics of the drill-bits, which are used to calibrate mathematical models.
Investigating the route to flutter in a pitch-plunge airfoil with freeplay nonlinearity subjected to input flow fluctuations
Authors: Magu Raam Prasaad R , Venkatramani J
Published: October 2018

Aeroelastic systems with freeplay nonlinearity can exhibit a wide variety of qualitatively different dynamical responses such as limit cycle oscillations and chaos in the pre-flutter regimes. Consequently, the bifurcation scenario in an aeroelastic system with freeplay nonlinearity under uniform flows have received considerable attention in the literature. However, in reality flows are far from deterministic and often possess a small temporal random fluctuations about a mean value. Input flow fluctuations have the potential to alter the stability and give rise to atypical routes to flutter. Indeed, recent studies have shown that under flow fluctuations the aeroelastic systems loses its stability via a regime of oscillations called intermittency. Further, it is observed that the presence of cubic hardening nonlinearity and input flow fluctuations with predominantly long time scales can give rise to “on-off” type intermittency. This dynamical behaviour is attributed to type of nonlinearity and relatively short time scale for the system to stay and exhibit distinct dynamics. Extending the mechanism of intermittency route to flutter in aeroelastic systems with other prominent types of nonlinearities, such as, freeplay have however, received minimal attention in the literature. The present study devotes itself to investigate the response dynamics of an airfoil with freeplay nonlinearity subjected to long time scale input flow fluctuations.
Tip-timing analysis of last stage steam turbine mistuned bladed disc during run-down
Authors: Rzadkowski Romuald , Kubitz Leszek , Maziarz Michał , Troka Pawel , Piechowski Leszek , Szczepanik Ryszard
Published: October 2018

This paper presents the experimental and numerical studies of last stage LP mistuned steam turbine bladed discs during run-down. The natural frequencies and mode shapes of the turbine bladed disc were calculated using an FE model. The influence of shaft was considered. The tip-timing method was used to find the mistuned bladed disc modes and frequencies. The numerical results were compared with experimental ones.
Vibration of a crane system model equipped with flexible links in the presence of kinematic task-based constraints
Authors: Jarzębowska Elżbieta , Urbaś Andrzej , Augustynek Krzysztof
Published: October 2018

The paper presents motion analysis of dynamic models of systems with flexible mechanical components and subjected to position and kinematic programmed constraints, which can be imposed as control goals, work or service task demands. The constrained dynamics is derived using an automated computational procedure dedicated to constrained systems. The procedure was successfully implemented to rigid models. A class of systems composed of flexible parts and subjected to programmed motions is considered in the paper. The novelty of the approach is in possibility of analyzing system motions, including vibration, in the presence of programmed constraints. The constrained motion is examined using a crane model equipped with a flexible link. The example delivers a realistic work situation, in which the crane carries loads and moves according to programmed constraints put on its trajectory and velocity.
Effect of noise on support vector machine based fault diagnosis of IM using vibration and current signatures
Authors: Gangsar Purushottam , Tiwari Rajiv
Published: October 2018

This paper analyzes the effect of noise on support vector machine (SVM) based fault diagnosis of IM (IM). For this, a number of mechanical (bearing fault, unbalanced rotor, bowed rotor and misaligned rotor) and electrical faults (broken rotor bar, stator winding fault with two severity levels and phase unbalance with two severity levels) of IM are considered here. The vibration and current signals are used here for the diagnosis. Different experiments were performed in order to generate these signals at various operating condition of IM (Speed and Load). Time domain feature are then extracted from the raw vibration and current signals obtained from the experiments. Then, the noise are added in the raw signals and the same features are extracted from this corrupted signals. The features from the original and corrupted signals are used to feed the classifier. The one-versus-one multiclass SVM are used here to perform multi-fault diagnosis. The comparative analysis of performance of the SVM classifier using data with and without noise is presented.
Study of finite amplitude capillary waves stability
Authors: Petrov Alexander , Lopushanski Mariana
Published: October 2018

The direct Lyapunov method is used to study capillary waves. The dynamic equations of the capillary wave are presented in the form of an infinite Euler-Lagrange chain of equations for the Stokes coefficients. The stationary solution found for these equations is the Crapper solution for capillary waves. With the help of energy and momentum conservation laws the Lyapunov function is constructed. It is shown that the Lyapunov function is positive definite with respect to any perturbations of waves surfaces with the period that is a multiple of the wave period.
Vibrational tests of a system with two coupled beams and a distributed tip mass
Authors: Rysak Andrzej , Rodgers Euan , Litak Grzegorz
Published: October 2018

We present the dynamical response of a nonlinear system designed for vibrational energy harvesting. The mechanical resonator is composed of two steel beams. The beams are coupled by a screw together at the ends with various distance element. Additionally, two piezoelectric patches are placed on their surface giving output powers on electric loads. In the article, we examine the output powers and dynamics of the system for variable frequency, different sizes of distance elements and several tip mass distributions.
Performance of broadband tristable energy harvesters
Authors: Zhou Shengxi , Litak Grzegorz , Cao Junyi
Published: October 2018

We analyze dynamical responses of energy harvesters with a mechanical resonator possessing three potential wells. The frequency spectral analysis of simulated systems demonstrates that additional sub-harmonic and super-harmonic resonances appear. These additional solutions make the frequency broadband effect and effectively increase the voltage output. We show the characteristic features of the obtained solutions. Appearance of coexisting periodic solutions and chaotic solutions are also shortly discussed.
An Identification of the unbalanced magnetic pull in generator at excitation and the hydropower machine model validation
Authors: Lozina Željan , Sedlar Damir , Tomac Ivan
Published: October 2018

A mechanical vibration inverse analysis has been performed on 150MW hydro-power machine in order to identify unbalanced magnetic pull. FEM model of the machine is developed according to design data. The System Equivalent Reduction Expansion Process is involved in model validation during the power-machine experimental run. The unbalanced magnetic pull in the generator is calculated from the verified model and monitored data.
Vibration analysis based on the spectrum kurtosis for adjustment and monitoring of ball bearing radial clearance
Authors: Georgiadis Anthimos , Gong Xiaoyun , Meier Nicolas
Published: October 2018

Vibration signal analysis is a common tool to detect bearing condition. Effective methods of vibration signal analysis should extract useful information for bearing condition monitoring and fault diagnosis. Spectral kurtosis (SK) represents one valuable tool for these purposes. The aim of this paper is to study the relationship between bearing clearance and bearing vibration frequencies based on SK method. It also reveals the effect of the bearing clearance on the bearing vibration characteristic frequencies This enables adjustment of bearing clearance in situ, which could significantly affect the performance of the bearings. Furthermore, the application of the proposed method using SK on the measured data offers useful information for predicting bearing clearance change. Bearing vibration data recorded at various clearance settings on a floating and a fixed bearing mounted on a shaft are the basis of this study
Semi-analytical approaches to vibrations induced by moving loads
Authors: Dimitrovová Zuzana
Published: October 2018

With the evolution of the computational power, there is a tendency to overlook analytical and semi-analytical solutions, despite their inherent obvious advantages. One should, however, be aware of the fact, that these solutions provide the necessary insight into the relevant physical phenomena and are accompanied by highly precise results, quickly obtainable without the necessity of additional numerical convergence tests. The objective of this contribution is to fill the gap in available semi-analytical solutions related to wave propagation induced by moving loads, with practical applications of high-speed rails. The structures that will be considered are composed of a beam and a supporting medium. The beam represents the interface between the structure and the moving object and will be simplified in conformity with the Euler-Bernoulli theory. In this paper the supporting structure will be considered as a two-parameter viscoelastic foundation and the moving object will be simplified by masses carrying constant forces with harmonic components, under assumption of tight contact. Special attention is paid to the proximity of moving masses.
Numerical analysis of geogrid contribution to railway track reinforcement
Authors: Lanca António , Dimitrovová Zuzana , Barroso Madalena , Fontul Simona
Published: October 2018

In this work, influence of geogrids on overall stabilization of railway tracks is studied numerically. It is expected that by geogrids implementation significant reduction in the downward propagation of stresses will be obtained, which consequently should assure more resilient long-term performance. In this first approach, however, only added value to the confinement level of the ballast layer is analysed, by evaluation of lateral deformations. A case study is related to a part of the Portuguese railway network. The track and the passing vehicle are modelled in commercial explicit dynamics software LS-DYNA. Firstly, the model is validated by comparison with experimental data. Then a fictitious scenario of the same track with a deteriorated region which is further rehabilitated by the geogrid placement is analysed. Different situations are compared in terms of lateral and vertical displacements at several levels, but for simplicity only rail deflections are shown here.
Vibrations induced by the passage of trains at various speeds and their effect on the structural response of buildings - an experimental and numerical analysis
Authors: Kożuch Barbara , Pachla Filip , Tatara Tadeusz
Published: October 2018

This paper presents a selection of vibration measurement results and analyses performed with regard to their harmfulness to residential buildings. The first part of the paper refers to the analysis of railway vibrations measured in situ at the foundation level of residential building. These vibration records were then used to assess the harmfulness of vibrations relating to each train speed. Assessment of the vibration harmfulness of the building was performed with an indicator of the perceptibility of vibration through a structure (WODB), according to the Polish standard. The second part of the study refers to the creation of dynamic models of buildings with the use of the ‘Diana’ software program and analysis of their responses to railway vibrations. The thresholds specified by the standard in any of the train speeds of up to 250 km/h were not exceeded. Nevertheless, propagation of vibrations induced by train passages and their effect on the structural response of buildings is a complex phenomenon. Without in situ measurements, it is hard to assess the impact of induced vibrations on buildings. As proven in the paper, a train moving on a track at various speeds does not uniformly make the vibration greater in each frequency band.
The effectiveness of polymer adhesive in reduction of vibrations of structural members
Authors: Lasowicz Natalia , Kwiecień Arkadiusz , Jankowski Robert
Published: October 2018

In this paper, the idea of using polymer adhesive as a damping layer is proposed. An experimental study of two aluminium cantilevered beams has been conducted. One of them presents a plain cantilevered beam, while the second one considers two aluminium beams bonded with a polymer adhesive of different thickness (0,5; 1,2; 1,75; 3,1 and 5 mm). The polymer adhesive considered in the study is a specially designed flexible two-component grout, which has high damping properties. The aim of the study is to determine dynamic parameters, such as natural frequencies and damping ratios of both beams, based on the tests in which analyzed elements have been induced to vibrations by a modal hammer. The behaviour of the beams under different additional weight, installed at the end of elements, has been studied. The results of the study clearly show that the response of the composite aluminium beam with polymer adhesive inside is substantially different then the response of the plain beam. The application of polymer adhesive leads to significant increase in structural damping. Based on the results, the method of using the polymer adhesive can be considered as an effective one in reduction of structural vibrations.
Prediction of position-dependent stability lobes based on reduced virtual model
Authors: Ksica Filip , Hadas Zdenek
Published: October 2018

The stability of a machining process is directly affected by the dynamic response between the tool and the workpiece. However, as the tool moves along the path, the dynamic stiffness of the machine tool changes. To determine the position-dependent dynamic stiffness accurately, a computationally efficient methodology based on a complex virtual model is presented. The virtual model is assembled using Finite Element Method and is effectively reduced via Component Mode Synthesis and transformation to a State-Space Multi-Input-Multi-Output system. Combination of these techniques allows time-efficient response simulations with significantly less computational effort than the conventional full Finite Element models. Furthermore, they describe the behaviour of the complex structure more accurately opposed to the commonly used models based on a simple 1 Degree-of-Freedom systems. The reduced model is used to simulate dynamic response of the structure to a cutting force during operation. A response is measured on an existing machine to modify the virtual model by incorporating fuzzy parameters, such as damping. The stability regions are calculated for variable positions, resulting in position-dependent lobe diagrams. The presented approach can be used to create a map of stable zones to predict and prevent unstable behaviour during operation.
Use of mechanical resonance in impact machines
Authors: Fiebig Wieslaw , Wrobel Jakub
Published: October 2018

An innovative method exploiting mechanical resonance in machines drive systems, especially useful in impact machines, has been developed. Accumulation of energy at resonance can be applied to the drive system in a similar way as flywheels in eccentric presses. Under resonance conditions, the total energy consumption of the oscillating mass is equal to the energy lost due the damping forces. Energy accumulated in the oscillator can be several times greater than the energy supplied continuously to the oscillator. The developed method can be used in many applications, especially in impacting machines. Finally, the energy demand of resonance punching press will be compared with the energy demand of eccentric press.
FE-BE computation of electromagnetic noise of a permanent-magnetic excited synchronous ma-chine considering dynamic rotor eccentricity
Authors: Clappier Marcel , Gaul Lothar
Published: October 2018

Electromagnetic noise in Electrical Machines (EMs) occurs due to vibrations caused by magnetic forces acting onto rotor and stator surface. This is the dominant source for the considered permanent-magnetic excited synchronous machine in this paper. The radiated electromagnetic noise is sequentially calculated by a Finite Element (FE) and Boundary Element (BE) computation. An electromagnetic FE model is created to determine magnetic forces. Structure-borne sound and rotor dynamics are calculated using a structural dynamic FE model for the EM housing and the rotor. In order to predict resonance frequencies and amplitudes as reliable as possible, it is important to know the direction-dependent stiffness of the laminated rotor stacks and mechanical joints as well as their structural damping. Thereby, the properties of the laminated stack can be determined experimentally by a shear and dilatation test. Mechanical joint properties can be modelled by Thin-Layer Elements (TLEs) and the overall damping by the model of constant hysteretic damping. The radiated sound power is determined by a direct BE computation. The influence of dynamic rotor eccentricity on radiated sound power is examined for a run-up of the EM. All FE models are verified by data from experimental modal analysis.
Experimental results for active control of multimodal vibrations by optimally placed piezoelectric actuators
Authors: Rossi Andrea , Botta Fabio , Maiozzi Roberto , Scorza Andrea , Sciuto Salvatore Andrea
Published: October 2018

Vibration damping is an effective strategy to enhance the life-cycle and performance of mechanical components. In this regard passive control systems involve lower costs and are easier to implement but their bandwidth is limited, whereas active systems provide larger bandwidth and higher adaptability to dynamic loads but higher costs and complexity are required. The recent advances in smart materials promoted the development of smart structures suitable for vibration damping and control. Between them the piezoelectric systems seem to be the most promising, however their efficiency relies on their placement. In a previous work the authors proposed and validated an analytical method to detect the optimal location of piezoelectric plates to control the multi-modal vibrations of a cantilever beam. Recent findings show that, if all actuators are activated simultaneously, the optimization problem can be traced back to the determination of the optimal potential distribution on all the piezoelectric actuators. In this paper the above method is taken into account and applied to a cantilever beam with 13 pairs of surface mounted PZT plates under the excitation provided by an electrodynamic shaker. The experimental damping of two flexural modes combinations has been performed by means of a special-purpose workbench and the assessment of the damping efficiency has been measured by means of a micro I.C.P. accelerometer. The results showed that the multimode vibrations of the cantilever beam can be efficiently damped if the potential distribution on all the PZT plates is optimized.
Non-destructive testing based on vibrations in the low to mid-frequency range
Authors: Becht Philip , Deckers Elke , Claeys Claus , Pluymers Bert , Desmet Wim
Published: October 2018

Recently, it has been shown that a Time Reversal MUltiple Signal Classification (TR-MUSIC) algorithm can be employed to detect defects in samples, which are both challenging in terms of material and in terms of geometrical complexity. This can be achieved by lowering the detection frequency as compared to most other TR and TR-MUSIC applications. In this case, the method operates in a low to mid-frequency range, where accurate models are still realizable. The method relies on the measurement of the frequency response function (FRF) between multiple excitation and sensor locations. These are gathered in a matrix, which then is decomposed in its singular vectors, serving as input for a MUSIC algorithm.

In order to improve the applicability of this method, it is shown how to adapt the algorithm, in order to reduce the number of excitation locations or the number of sensors significantly. This results in a considerable speed-up for the application of this non-destructive testing strategy. Furthermore, it is investigated numerically how the robustness of the detection result under the influence of random measurement errors behaves if the number of excitation/sensor locations is reduced. Additionally, the dependency between, the decrease of the number of excitation/sensor locations and the types of defects, which can be detected is studied.
Closure of an oroantral fistula by bone autograft: a case report
Authors: Amroun Samy , Zouari Yassine , Bouattour Ayman
Published: October 2018

Introduction: The management of the oroantral fistula is mainly focused on th closure of the mucosa. The surgical management restoring the underlying bone defect are seldom. Maintaining this defect may compromise implant rehabilitation in this sector. The purpose of this article was to show, through a clinical case, an alternative way to manage an oroantral fistula and the bone tissue defect in the same time. Observation: After a rigourous clinical and radiological observation of a 2-year oroantral fistula, an impacted autologous bone graft of the maxillary tuberosity followed by a water tight closure of the mucosa, were realized in a 50-year old patient. Commentary: Using this surgical technique was successful for the closure of the mucosa as for the bone defect reconstruction. A consolidation was noticed and an pre-implant management and a dental implant placement could be realized. Conclusion: The choice of this surgical technique for the management of an oroantral fistua had a direct influence on the future prosthetic rehabilitation. The surgical technique presented for this case could be an interesting approach because the fixed or removable prosthetic treatment will be more effective if the maxillary bone tissue is reconstructed.
Recommandations de bonnes pratiques professionnelles entre le rationnel et le passionnel
Authors: Secret-Bobolakis Isabelle
Published: October 2018

Cet article propose une analyse de la méthodologie des recommandations de bonnes pratiques de la HAS dans le champ des troubles du spectre de l’autisme chez l’adulte. Il propose une discussion sur un certain nombre de mécanismes induisant des biais dans les recommandations : consensus, sélection des membres des groupes de travail, sélection des articles scientifiques.
Die Acid Pocket: ein neues Ziel für die Behandlung der gastroösophagealen Refluxkrankheit
Authors: Sauter Matthias , Fox Mark
Published: October 2018

Die gastroösophageale Refluxkrankheit stellt die häufigste Ursache für Symptome des oberen Gastrointestinaltrakts dar.

Der Säure-Reflux in der postprandialen Phase ist der prädominante Faktor der gastroösophagealen Refluxkrankheit (gastro-esophageal Reflux disease, GERD) und führt zu Beschwerden wie Sodbrennen und saurem Aufstoßen. Die chronische Säureexposition des Ösophagus führt zudem zu Komplikationen wie der Refluxösophagitis, peptischen Stenosen, dem Barrett-Ösophagus oder dem Adenokarzinom.

Das Ausmaß an mukosalen Schäden und Symptomen hängt von zwei Hauptfaktoren ab: (1.) dem Säuregehalt des Refluxats, welches primär von der gastralen Säureproduktion und der Verteilung der Säure im Magen abhängt sowie (2.) der Häufigkeit / Dauer an Refluxepisoden und der Stärke der Refluxbarriere am gastroösophagealen Übergang. Das Konzept der Acid Pocket ist ein Versuch, diese Faktoren in einem gemeinsamen Pathomechanismus zu vereinen.

Die Acid Pocket beschreibt eine Ansammlung von Magensäure am gastroösophagealen Übergang in der postprandialen Phase und stellt ein wichtiges Reservoir für gastroösophageale Refluxepisoden dar. Die Acid Pocket ist sowohl bei Gesunden wie auch bei Refluxpatienten vorhanden. Insbesondere bei Patienten mit einer Hiatushernie und / oder einem hypotensiven unteren Ösophagus-Sphinkter kann sich die Acid Pocket aber über den gastroösophagealen Übergang hinaus in den distalen Ösophagus ausbreiten, was zu einer erhöhten Säureexposition insbesondere des distalsten Ösophagus-Abschnitts und somit Refluxbeschwerden führt.

In den letzten Jahren wurde die Acid Pocket als mögliches Ziel von pharmakologischen und chirurgischen GERD-Therapien postuliert. Säurehemmende Medikamente wie z. B. Protonen-Pumpen-Inhibitoren reduzieren den Säuregehalt der Acid Pocket, wogegen Alginat-Substanzen, Prokinetika und die Fundoplikatio-Operation die Acid Pocket nach distal weg vom gastroösophagealen Übergang dislozieren.
Die Effekte nicht-pharmakologischer, gesundheitsfördernder Interventionen bei Menschen mit schweren psychischen Erkrankungen
Authors: Richter Daniel , Gühne Uta , Stein Janine , Weinmann Stefan , Becker Thomas , Riedel-Heller Steffi
Published: October 2018

Hintergrund Menschen mit schweren psychischen Erkrankungen sind deutlichen Risiken somatischer Morbidität und erhöhter Mortalität ausgesetzt. Gesundheitsfördernde Interventionen sollen die Risiken dafür reduzieren. Die Arbeit trägt die Evidenz in diesem Bereich zusammen.

Methodik Systematische Suche in Medline, EMBASE, PsycINFO und der Cochrane Library nach Übersichtsarbeiten und RCTs.

Ergebnisse Gesundheitsfördernde Interventionen zeigten nahezu durchweg positive Effekte in Bezug auf die untersuchten Parameter.

Schlussfolgerung Weitere nachhaltige Untersuchungen sind erforderlich.
In Vitro and Ex Vivo Effects of Silymarin Derivatives on Proinflammatory Cytokine Secretion Using a Murine Colonic Strip Model
Authors: Fitzpatrick Leo , Mokrushin Ella , Talbott George , Woldermariam Tibebe
Published: October 2018

Silymarin has anti-inflammatory properties and documented anti-colitis activity. Our prior study determined that in vitro treatment with certain extracted fractions of silymarin inhibited stimulated proinflammatory cytokine secretion from cell lines relevant to colitis. In this study, colitis was induced in mice by giving dextran sulfate sodium drinking water for 6 days. The ex vivo effects of crude silymarin extract, two different silymarin fractions, as well as commercially derived silibinin and isosilibinin were examined by determining the secretion of MIP-2, TNF-α, and IL-17 in cell culture media from colonic strips. Further, the effects of silymarin-derived treatments on IL-8 and TNF-α secretion induced by the colitis supernatant was characterized with HT-29 colonic epithelial and RAW 264.7 macrophage cell lines. Prominent inhibition of MIP-2 and TNF-α secretion from colonic strips of mice with/without dextran sulfate sodium-induced colitis was observed with various silymarin treatments. Further, inhibition of dual (IL-23+IL-1β) cytokine-stimulated secretion of IL-17 from colonic strips of mice was found with certain silymarin treatments. Significant attenuation of TNF-α secretion from colitis supernatant-stimulated RAW 264.7 cells was observed for crude silymarin extract and isosilibinin treatments. Finally, inhibition of IL-8 secretion from the colitis supernatant-stimulated HT29 colonic epithelial cell line was found with isosilibinin. These results contribute to the identification of silymarin-derived flavonoligans with optimal anti-inflammatory properties for further testing in colitis models.
Factors Influencing Sustained Engagement with ECG Self-Monitoring: Perspectives from Patients and Health Care Providers
Authors: Reading Meghan , Baik Dawon , Beauchemin Melissa , Hickey Kathleen , Merrill Jacqueline
Published: October 2018

Background Patient-generated health data (PGHD) collected digitally with mobile health (mHealth) technology has garnered recent excitement for its potential to improve precision management of chronic conditions such as atrial fibrillation (AF), a common cardiac arrhythmia. However, sustained engagement is a major barrier to collection of PGHD. Little is known about barriers to sustained engagement or strategies to intervene upon engagement through application design.

Objective This article investigates individual patient differences in sustained engagement among individuals with a history of AF who are self-monitoring using mHealth technology.

Methods This qualitative study involved patients, health care providers, and research coordinators previously involved in a randomized, controlled trial involving electrocardiogram (ECG) self-monitoring of AF. Patients were adults with a history of AF randomized to the intervention arm of this trial who self-monitored using ECG mHealth technology for 6 months. Semistructured interviews and focus groups were conducted separately with health care providers and research coordinators, engaged patients, and unengaged patients. A validated model of sustained engagement, an adapted unified theory of acceptance and use of technology (UTAUT), guided data collection, and analysis through directed content analysis.

Results We interviewed 13 patients (7 engaged, 6 unengaged), 6 providers, and 2 research coordinators. In addition to finding differences between engaged and unengaged patients within each predictor in the adapted UTAUT model (perceived ease of use, perceived usefulness, facilitating conditions), four additional factors were identified as being related to sustained engagement in this population. These are: (1) internal motivation to manage health, (2) relationship with health care provider, (3) supportive environments, and (4) feedback and guidance.

Conclusion Although it required some modification, the adapted UTAUT model was useful in understanding of the parameters of sustained engagement. The findings of this study provide initial requirement specifications for the design of applications that engage patients in this unique population of adults with AF.
Vestibular Migraine with Visual Aura and Olfactory Hallucination in Children: Two Case Reports
Authors: Villa T.R. , Agessi L.M.
Published: October 2018

Background Approximately 3.9% children with migraine have olfactory hallucination which was defined as a perception of a smell without the substantial existence of any physical odor.

Case We described the first two cases of children with vestibular migraine, presenting visual aura and olfactory hallucination. ​ We reported two children with vertigo, visual aura, and olfactory hallucination before the headache who were responsive to topiramate.

Conclusion The clinical description of olfactory hallucination presented some characteristics of migraine aura. Olfactory hallucinations could be inserted as a migraine aura in International Classification of Headache Disorders.
Liquid crystal polymer receiver modules for electron cyclotron emission imaging on the DIII-D tokamak
Authors: Zhu Y. , Ye Y. , Yu J-H. , Tobias B. , Pham A-V. , Wang Y. , Luo C. , Domier C. W. , Kramer G. , Ren Y. , Diallo A. , Nazikian R. , Chen M. , Yu G. , Luhmann N. C.
Published: October 2018

A new generation of millimeter-wave heterodyne imaging receiver arrays has been developed and demonstrated on the DIII-D electron cyclotron emission imaging (ECEI) system. Improved circuit integration, improved noise performance, and enhanced shielding from out-of-band emission are made possible by using advanced liquid crystal polymer (LCP) substrates and monolithic microwave integrated circuit (MMIC) receiver chips. This array exhibits ∼15 dB additional gain and >30× reduction in noise temperature compared to previous generation ECEI arrays. Each LCP horn-waveguide module houses a 3 × 3 mm GaAs MMIC receiver chip, which consists of a low noise millimeter-wave preamplifier, balanced mixer, and IF amplifier together with a local oscillator multiplier chain driven at ∼12 GHz. A proof-of-principle partial LCP instrument with 5 poloidal channels was installed on DIII-D in 2017, with a full proof-of-principle system (20 poloidal × 8 radial channels) installed and commissioned in early 2018. The enhanced shielding of the LCP modules is seen to greatly reduce the sensitivity of ECEI signals to out-of-band microwave noise which has plagued previous ECEI studies on DIII-D. The LCP ECEI system is expected to be a valuable diagnostic tool for pedestal region measurements, focusing particularly on electron temperature evolution during edge localized mode bursting.
Secondary electron emission detectors for neutral beam characterization on C-2W
Authors: Titus J. B. , Magee R. M. , Isakov I. , Pirogov K. , Korepanov S. ,   TAE Team
Published: October 2018

Heating, current drive, and partial fueling from neutral beam injection are essential to sustainment of C-2W field-reversed configuration plasmas. C-2W has eight 2.1 MW neutral beams (16.8 MW of total electrical power), capable of providing a beam of 15 keV hydrogen neutrals for 30 ms. To maximize the effectiveness of neutral beam injection, duct losses must be minimized by maintaining beam alignment and optimizing beam current for minimum divergence. Each beam terminates on a vertical and horizontal array of secondary electron emission detectors (nine in the vertical, seven in the horizontal, and sharing one in the middle). The molybdenum detectors are spatially separated to characterize the beam size and alignment. With knowledge of the geometry of the vacuum ducts and horizontal and vertical beam profiles from test stand measurements, the focal length, divergence, and power loss were calculated. Through characterization, the set of neutral beams are optimized to inject up to 12 MW of power into the confinement vessel throughout the plasma discharge.
Pixel-to-pixel variation on a calibrated PILATUS3-based multi-energy soft x-ray detector
Authors: VanMeter P. , Delgado-Aparicio L. F. , Reusch L. , Pablant N. , Maddox J. , Rissi M. , Luethi B. , Donath T. , Schulze-Briese C. , Hill K. , Den Hartog D.
Published: October 2018

A multi-energy soft x-ray pin-hole camera based on the PILATUS3 100 K x-ray detector has recently been installed on the Madison Symmetric Torus. This photon-counting detector consists of a two-dimensional array of ∼100 000 pixels for which the photon lower-threshold cutoff energy Ec can be independently set for each pixel. This capability allows the measurement of plasma x-ray emissivity in multiple energy ranges with a unique combination of spatial and spectral resolution and the inference of a variety of important plasma properties (e.g., Te, nZ, Zeff). The energy dependence of each pixel is calibrated for the 1.6–6 keV range by scanning individual trimbit settings, while the detector is exposed to fluorescence emission from Ag, In, Mo, Ti, V, and Zr targets. The resulting data for each line are then fit to a characteristic “S-curve” which determines the mapping between the 64 possible trimbit settings for each pixel. The statistical variation of this calibration from pixel-to-pixel was explored, and it was found that the discreteness of trimbit settings results in an effective threshold resolution of ΔE < 100 eV. A separate calibration was performed for the 4–14 keV range, with a resolution of ΔE < 200 eV.
Growth and characterization of detector-grade CdMnTe by the vertical Bridgman technique
Authors: Roy U. N. , Okobiah O. K. , Camarda G. S. , Cui Y. , Gul R. , Hossain A. , Yang G. , Egarievwe S. U. , James R. B.
Published: October 2018

We grew Cd1-xMnxTe crystals with a nominal Mn concentration of 5% by the vertical Bridgman growth technique. The compositional variation along the length of the grown ingot was studied by powder X-ray diffraction. The composition was found to be uniform along the growth direction. The achieved resistivity was 1-2.5 x1010 ohm-cm with a mobility-lifetime (μτ) product value for electrons of ∼1.7x10-3 cm2/V. An energy resolution of ∼7.5% at 662 keV was achieved for a 9-mm long Frisch grid detector fabricated from an ingot grown using as-received starting materials.
A local tensor that unifies kinetic energy density and vorticity in density functional theory
Authors: Sen Sangita , Tellgren Erik I.
Published: October 2018

We present a kinetic energy tensor that unifies a scalar kinetic energy density commonly used in meta-generalized gradient approximation functionals and the vorticity density that appears in paramagnetic current-density-functional theory. Both types of functionals can thus be subsumed as special cases of a novel functional form that is naturally placed on the third rung of Jacob’s ladder. Moreover, the kinetic energy tensor is related to the exchange hole curvature, is gauge invariant, and has very clearcut N-representability conditions. The latter conditions enable the definition of an effective number of non-negligible orbitals. Whereas quantities such as the electron localization function can discriminate effective one-orbital regions from other regions, the present kinetic energy tensor can discriminate between one-, two-, three-, and four-or-more orbital regions.
Effects of Fe doping on anomalous specific heat and XAFS oscillation in antiferromagnetic metal Mn3Si
Authors: Hiraka H. , Ohoyama K. , Kosaka M. , Matsumura D.
Published: October 2018

The specific heat of Mn3−xFexSi was measured over a wide temperature range. Aside from the lattice and electronic specific heat components, another component had a significant contribution to the specific heat at low temperatures in the case of x = 0.2; however, its contribution decreased when x = 1.0. It is observed that the net component was retained at temperatures significantly higher than TN for both x. The XAFS spectra of the Mn K-edge for x = 0 not only indicated a smooth structure near the edge, but also an unusually small amplitude in the extended high energy region; however, these features disappeared with Fe doping. The specific heat and XAFS data were discussed in terms of the charge degree of freedom or electronic inhomogeneity.
Sidewall profile reconstruction of microstructures with high aspect ratio based on near-infrared light scanning interferometry
Authors: Shi Jianhua , Han Bingchen
Published: October 2018

Sidewall profile reconstruction of microstructures with the high aspect ratio is a problem urgently to be solved in MEMS field. In this paper, a measuring method based on near-infrared light scanning interferometry (NILSI) is presented according to the transmission principle of semiconductor materials in the infrared light region. The NILSI is extended from the white light to near-infrared light and from surface profile reconstruction to sidewall profile reconstruction. The NILSI system is constituted by a near-infrared light source, an interference microscope, infrared CCD, piezoelectric ceramics (PZT) with high accuracy and the data acquisition system. The test sample is taken from GaAs microstructures with high aspect ratio and made by two different height steps for measuring with different typical testing equipment. Near-infrared light vertical scanning interference (NILVSI) is improved to compensate optical path difference (OPD) and the large surface roughness. The sidewall profile of the sample is obtained and compared with that of scanning electron microscopy (SEM) and white light scanning interferometry (WLSI). Test results demonstrate that the steps have 2.115 μm and 0.762 μm relative heights and 1.34 % and 2.14% relative errors respectively. There is a good agreement with the results of SEM and WLSI. The system can reconstruct the sidewall profile of microstructures with high aspect ratio.
Factors affecting the properties of highly conductive flexible ultrathin ITO films in confined large area magnetron sputtering in three dimensions
Authors: Sahu Bibhuti Bhusan , Wen Long , Kwon Ji Hye , Han Jeon Geon
Published: October 2018

A large area magnetron source with the strongly confined magnetic field from all direction is applied for the deposition of flexible ultrathin ITO (UT-ITO) films of thickness 30 nm at room temperature for their applications as transparent electrodes. The films show a minimum resistivity of ∼5.0 x 10-4 Ωcm and high transmittance >80% at wavelengths of 400-700 nm. Measurements and data reveal that a high plasma density, high energy flux, and a relatively low concentration of negative oxygen ions (NOIs) to the flux of positive ions (PIs) induce lower mechanical stress to the growing films, which enables a lower resistivity and superior crystallinity with the smooth surface. The capability of the magnetron source and the characteristic plasma properties are studied in light of the resulting film properties. The considerably lower resistivity with higher carrier concentration and mobility of the UT-ITO films prepared at a high power density of 3 W/cm2 and a low O2 gas flow can be attributed to the growth of crystallized UT-ITO films, resulting in the combination of the oxygen vacancy and substitution of Sn4+ to In3+ site through the deposition of a high energy flux and a low flux ratio of NOIs to PIs.
Morality
Authors: Graham Jesse , Valdesolo Piercarlo
Published: October 2018

Since the early 2000s, morality research in personality and social psychology has exploded, with more articles on moral judgment and moral behavior published in the first fifth of the 21st century than the entirety of the 20th century. However, while moral psychology is flourishing in the field, it remains deeply divided in several respects, with largely separate literatures for moral judgment and moral behavior, as well as separations between individual differences and situational effects for each. This chapter follows the two main cleavages in moral psychology, covering cultural and individual differences in moral judgment, situational effects on moral judgment, cultural and individual differences in moral behavior, and situational effects on moral behavior. Further, it highlights evidence of person–situation interactions for both moral judgment and moral behavior, and maps out several future directions for moral psychology.
Personality, Social Psychology, and Psychopathology
Authors: Costanzo Philip R. , Hoyle Rick H. , Leary Mark R.
Published: October 2018

This chapter considers the roots of the tripartite marriage of personality, social, and abnormal psychology. It calls for rekindling the conjunctive hopes to put normal and abnormal behavior, thought, and feeling on the same continua. Lewinian field theory and its definition of locomotion forces in the life space provide a frame. It illustrates the overlap of personality and social psychology with ideas and questions of abnormal behavior scholars. The analyses turn to Person × Environment interaction dynamics in life space. Meaning-making and multiple “worldview” existential models are defined as forces constituting the dynamics defining permeability of adaptive regions of the “life space.” Human adaptation in critical regions or domains of life experience in the behavioral field illustrate dynamics: the domains of regulatory transactions and of acceptance, social affection, and relationships. These are pertinent for parsing continua of normal-to-abnormal adaptation and conjoining psychopathology with humans’ struggles of personal and social significance.