bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Network Science Measures to Predict the Lexical Decision Performance of Adults Who Stutter
Authors: Castro Nichol , Pelczarski Kristin M. , Vitevitch Michael S.
Published: June 2017

Purpose

Methods from network science have examined various aspects of language processing. Clinical populations may also benefit from these novel analyses. Phonological and lexical factors have been examined in adults who stutter (AWS) as potential contributing factors to stuttering, although differences reported are often subtle. We reexamined the performance of AWS and adults who do not stutter (AWNS) from a previously conducted lexical decision task in an attempt to determine if network science measures would provide additional insight into the phonological network of AWS beyond traditional psycholinguistic measures.

Method

Multiple regression was used to examine the influence of several traditional psycholinguistic measures as well as several new measures from network science on response times.

Results

AWS responded to low-frequency words more slowly than AWNS; responses for both groups were equivalent for high-frequency words. AWS responded to shorter words more slowly than AWNS, producing a reverse word-length effect. For the network measures, degree/neighborhood density and closeness centrality, but not whether a word was inside or outside the giant component, influenced response times similarly between groups.

Conclusions

Network analyses suggest that multiple levels of the phonological network might influence phonological processing, not just the micro-level traditionally considered by mainstream psycholinguistics.
Clinical Supervision in a Medical Setting: A Preliminary Study About the Practices and Beliefs of Expert and Novice Clinician Supervisors
Authors: Taliancich-Klinger Casey , Cooperson Solaman
Published: June 2017

This project explores perceptions of the clinical supervision practices from the perspective of expert and novice speech-language pathologists (SLPs) in a medical setting. Expert and novices may have different philosophies and beliefs about supervision that could impact a young clinician's learning (Peña & Kiran, 2008). An expert was defined as having more than five years of clinical experience in the medical setting with supervision experience of at least 10 students. Novice clinicians had worked for less than five years and had supervised a minimum of one student. An interview adapted from counseling literature (Okech & Rubel, 2009), was used to collect data on beliefs about supervision practices of two expert and two novice SLPs supervising graduate students at a hospital in Texas. Results indicated that novices were more likely to experience stress related to supervision and did not provide regular feedback to their supervisees in comparison to their expert peers. Experts were more likely to have a positive view of supervision and provide feedback more consistently. These reported differences in perceptions have implications for clinical teaching as novices and experts may have different ways of supervising potentially impacting learning for beginning speech-language pathology clinicians.
Performance of maximum‐ratio combining‐enabled heterodyne detection for free‐space optical systems under mixture‐Gamma fading channels and pointing errors
Authors: Miridakis N.I. , Vergados D.D. , Michalas A.
Published: June 2017

The performance of maximum‐ratio combining for free‐space optical systems using heterodyne detection is analytically studied. The analysis includes the joint effect of turbulence‐ and misalignment‐induced channel fading. Particularly, novel closed‐form expressions regarding the scintillation index, outage probability and average bit‐error rate are derived. Based on these results, some useful outcomes are manifested, such as the system diversity order, the crucial role of diversity branches, and the impact of composite channel fading onto the system performance.
Wide‐range, high‐precision and low‐complexity MPPT circuit based on perturb and observe algorithm
Authors: Jiang Rucheng , Han Yan , Zhang Shifeng
Published: June 2017

A novel CMOS maximum power point (MPP) tracking circuit with high‐power throughput, high‐tracking efficiency and low complexity for solar converters is presented. The power acquisition circuit guarantees the tracking efficiency and the control logic module which implements the multiplexing of power conversion, power storage and power comparison, simplifies MPPT circuit significantly. Simulation and measurement results show that the MPPT circuit operates properly and the tracking efficiency stays larger than 99.9% with the output current of the power acquisition circuit varying from 5 to 100 μA
Design and prototyping of a new flywheel energy storage system
Authors: Ghaemi Ehsan , Mirsalim Mojtaba
Published: June 2017

This study presents a new ‘cascaded flywheel energy storage system’ topology. The principles of the proposed structure are presented. Electromechanical behaviour of the system is derived base on the extension of the general formulation of the electric machines. Design considerations and criteria are discussed and a general procedure for designing of such energy storage system is developed. Typical machine is designed and an analogy between it and the conventional one is discussed. Comparison shows significant improvements in energy density and utility requirements of the proposed system in comparison to the conventional structure. Dynamic response of the designed machine is studied in various conditions as the stand‐alone and also as the grid‐connected system. Finally, a typical three‐stage system is designed, prototyped and tested which shows a good agreement between an analytical and experimental analysis.
Fault diagnosis of rotor winding inter‐turn short circuit for sensorless synchronous generator through screw
Authors: Yucai Wu , Qianqian Ma , Bochong Cai
Published: June 2017

Timely and accurate detection of the rotor winding inter‐turn short‐circuit fault of a synchronous generator can reduce the more serious damages caused by fault deterioration and economic losses, so developing online detection methods with high sensitivity is necessary. On the basis of the structural characteristics of the synchronous generator, this study proposes a sensorless online detection method for rotor winding inter‐turn short‐circuit faults, respectively, taking a 300 MW turbo generator and a 550 MW hydro‐generator as the objects of finite‐element simulation. The results show that the new fault diagnosis method of the rotor winding inter‐turn short circuit for the sensorless synchronous generator has high sensitivity and can realise real‐time monitoring of the faults.
Bifurcation of lane change on highway for large bus
Authors: Tao Peng , Zhi‐Wei Guan , Rong‐Hui Zhang , Ling Huang , Hong‐Guo Xu , Hong‐Fei Liu
Published: June 2017

In this study, a new method is proposed for analysing the non‐linear dynamics and stability in lane changes on highways by large buses. Unlike most of the literature associated with a simulated linear dynamic model for large buses, a verified 4DOF mechanical model with non‐linear tire based on vehicle test is used in the lane‐change simulation, including sinusoidal steering and steer returning. According to Jacobian matrix eigenvalues of the vehicle model, bifurcations of steady steering, sinusoidal steering and steer returning with disturbance on highways are investigated using a numerical method. The numerical simulation results reveal that Hopf bifurcations are identified in steady and sinusoidal steering conditions, which translates into an oscillatory behaviour leading to instability. Various equilibrium forms of stability are found, as well as saddle and Hopf bifurcations with disturbance ζ variety. The derived knowledge of the bifurcations set is hugely important to fully understand the actual dynamic motions of vehicles when lane changing on an even surface. It is a valuable reference for safety design of large buses to improve the traffic safety of driver–vehicle–road closed‐loop system.
Performance of a dipole placed above a novel double layered via‐less high impedance surface
Authors: Gupta Gaurangi , Harish Ayyangar R.
Published: June 2017

A novel double layer via‐less high impedance surface (HIS) has been used as a reflector for a dipole antenna. The structure consists of two layers of metallic patches, where one layer is rotated by 45° with respect to other thus producing an interwoven geometry. This facilitates the HIS to be symmetric and flexible as a reflector for achieving desired performance. The antenna properties with the proposed HIS are compared against two other HIS structures available in the literature, namely single layered structure consisting of metal patches with and without via. The authors also demonstrate the performance improvement by changing the orientation of the dipole with respect to the HIS structure.
Modified current distribution for analysis of spiral antennas
Authors: Jalali‐Deel Ahmad , Nayyeri Vahid , Soleimani Mohammad , Naghdehforushha Seyed‐Arash
Published: June 2017

Circular current distribution is conventionally used to model current on spiral antennas. However, this model does not include the radial component of the current on the spiral arms. Therefore, it is valid only for the spiral antennas with very small values of the growth rate, where the radial component of the current is negligible. This study proposes a modified current distribution including both radial and azimuthal components of the current, hence, the modified model is not restricted to very small values of the growth rate. Using the modified current distribution, the radiation characteristics of spiral antennas with different growth rates are extracted. Validation is achieved by comparison of the results with those obtained by full wave numerical simulations.
One‐day ahead wind speed/power prediction based on polynomial autoregressive model
Authors: Karakuş Oktay , Kuruoğlu Ercan E. , Altınkaya Mustafa A.
Published: June 2017

Wind has been one of the popular renewable energy generation methods in the last decades. Foreknowledge of power to be generated from wind is crucial especially for planning and storing the power. It is evident in various experimental data that wind speed time series has non‐linear characteristics. It has been reported in the literature that nonlinear prediction methods such as artificial neural network (ANN) and adaptive neuro fuzzy inference system (ANFIS) perform better than linear autoregressive (AR) and AR moving average models. Polynomial AR (PAR) models, despite being non‐linear, are simpler to implement when compared with other non‐linear AR models due to their linear‐in‐the‐parameters property. In this study, a PAR model is used for one‐day ahead wind speed prediction by using the past hourly average wind speed measurements of Çeşme and Bandon and performance comparison studies between PAR and ANN‐ANFIS models are performed. In addition, wind power data which was published for Global Energy Forecasting Competition 2012 has been used to make power predictions. Despite having lower number of model parameters, PAR models outperform all other models for both of the locations in speed predictions as well as in power predictions when the prediction horizon is longer than 12 h.
Fatigue assessment by electroencephalogram measured with candle‐like dry microneedle electrodes
Authors: Kudo Yuta , Arai Miyako , Miki Norihisa
Published: June 2017

This work reports on the creation of an electroencephalogram (EEG) index and the discovery of a power ratio related to alpha band frequencies (8–13 Hz) that were experimentally found to have a high correlation with human mental fatigue. The EEG was measured from occipital lobe of the human brain by microfabricated dry candle‐like microneedle electrodes (CMEs) that can avoid hairs and penetrate through the high‐impedance stratum corneum. The newly identified EEG index exhibited higher correlations to mental fatigue states, which were rated subjectively via the visual analogue scale (VAS), than did heart rate variance, which is often used as the objective measure of fatigue levels. Interestingly, it was found that the index trend changed 10 min before the VAS did, which implies that the index could assess the onset of mental fatigue even before the subjects recognised it themselves. The identification of this EEG index, along with the ease of obtaining EEG measurements via CME, which is due to the fact that the CME does not require any skin preparation or conductive gels and can acquire EEGs from hair‐covered parts of the scalp, can be expected to promote practical fatigue assessment applications that use EEGs.
Analyses of particle size and magnetisation of magnetic nanoparticles via Minitab Statistical Software
Authors: Yaman Sertaç , Öztürk Yavuz
Published: June 2017

In this work, the influence of statistically determined synthesis parameters on the properties of magnetite (Fe3O4) nanoparticles (MNPs) was investigated. The synthesis temperature and pH parameters generated with the help of Minitab Statistical Software v.16 were selected to examine. The effects of these parameters on MNPs produced by using co‐precipitation method were presented. The average particle size and saturation magnetisation were measured, which were chosen for statistical evaluation in the software. The fit test results of Minitab show that the initial condition parameters and results of the selected measurements in correlation to fit in the normal distribution. It was also shown that the results of saturation magnetisation and particle size depend on solution pH and the temperature is compatible with several studies. Outcomes of this work indicate that this software can be used for determining a minimum number of trials needed to find the influence of synthesis parameters (temperature, pH) on the material properties and so decrease the time for synthesis of new material with desired properties.
Concept of Combined Femoral and Tibial Osteotomies
Authors: Sigwalt Loic , Rubens-Duval Brice , Chedal-Bornu Billy , Pailhe Regis , Saragaglia Dominique
Published: June 2017

Medial knee osteoarthritis is not uncommon, and high tibial osteotomy (HTO) for some surgeons is a unique treatment option for young and active patients. However, the deformity is not always located at the level of proximal part of the tibia and the overcorrection needed to achieve a lasting functional result can lead to an oblique joint line. To avoid this undesirable effect to the joint line, a double-level osteotomy (DLO), one at the distal part of the femur and another one at the proximal part of the tibia, is a viable option. The aim of this article is to present the preoperative radiological assessment, the operative procedure, the indications of HTO, distal femoral osteotomy (DFO), and DLO presenting the rationale behind the treatment options. Long-leg radiographs are mandatory to measure the hip–knee–ankle angle, and the femoral and tibial mechanical axes to plan the location of the osteotomy. The best indication for DLO is a severe varus knee deformity with femoral and tibial mechanical axes in varus. This argument can be applied to a genu valgum deformity, especially when the femur is in valgus as well as the tibia, which is not rare. Although the operative technique is demanding, the biggest challenge is not the procedure itself but rather how to reach the exact degree of overcorrection. Computer-assisted surgery is a good alternative and can improve the accuracy of the surgery.
A Less Invasive Approach to Periacetabular Osteotomy Improves Patient Reported Outcomes without Compromising Orientation
Authors: Pelt Christopher , Wingert Nathaniel , Erickson Jill , Anderson Mike , Peters Christopher
Published: June 2017

A less-invasive modification of the approach to periacetabular osteotomy (PAO) has recently been popularized by sparing the rectus femoris origin (RS-PAO). The RS-PAO approach with its lack of intra-articular inspection and associated treatment is novel, and there are few published results on the outcomes following this technique. We report on a consecutive series of RS-PAO cases, including patient reported outcomes (PROs), acetabular fragment reorientation, and complications. We reviewed a consecutive series of 103 patients (103 procedures) who underwent RS-PAO from June 2012 to January 2016 with a mean 2-year follow-up. We collected PROs, radiographic, and clinical outcomes. PROs consisted of PROMIS (Patient Reported Outcomes Measurement Information System) measures covering the domains of physical function, mental health, and a numeric pain score (NPS). Physical function and mental health were reported as standardized T-scores. Appropriate bivariate statistics were used for the analyses. Physical function improved from a preoperative mean of 39.9 (95% confidence interval [CI], 38.0–42.0) to a postoperative value of 50.0 T-score units (95% CI, 47.01–52.7; dav = 1.2). The PROMIS global mental-health T-scores improved from a preoperative median of 45.8 (interquartile range [IQR], 41.1–50.8) to a postoperative value of 53.3 (IQR, 50.8–59.0; p < 0.001, correlation coefficient [r] = 0.77). Pain decreased from a median preoperative value of 6 (IQR, 3–8) to a postoperative value of 2 (IQR, 1–3; p < 0.001, r = 0.71). The postoperative acetabular index (AI) was within the correction goal in 75% of the cases (77/103) and lateral center-edge angle (LCEA) was within goal in 87% (90/103) of the cases. Complications included intraoperative ischial fracture (n = 1), nonunion of the superior ramus (n = 1), ischiofemoral impingement (n = 1), delayed union (n = 1), and wound dehiscence (n = 2). There have been no reoperations for intra-articular pathology. The data demonstrated that using the RS-PAO technique without concomitant intra-articular work allows for appropriate acetabular positioning as well as significant improvement in physical function, mental health, and pain with an acceptable short-term complication profile and low rate of reoperation.
Combined Effect of the PGR +331C > T, CYP17A1 -34A > G and CYP19A1 1531G > A Polymorphisms on the Risk of Developing Endometriosis
Authors: Cardoso Jéssica Vilarinho , Machado Daniel Escorsim , Ferrari Renato , Silva Mayara Calixto da , Berardo Plínio Tostes , Perini Jamila Alessandra
Published: June 2017

Purpose To evaluate the magnitude of the association of the polymorphisms of the genes PGR, CYP17A1 and CYP19A1 in the development of endometriosis.

Methods This is a retrospective case-control study involving 161 women with endometriosis (cases) and 179 controls. The polymorphisms were genotyped by real-time polymerase chain reaction using the TaqMan system. The association of the polymorphisms with endometriosis was evaluated using the multivariate logistic regression.

Results The endometriosis patients were significantly younger than the controls (36.0 ± 7.3 versus 38.0 ± 8.5 respectively, p = 0.023), and they had a lower body mass index (26.3 ± 4.8 versus 27.9 ± 5.7 respectively, p = 0.006), higher average duration of the menstrual flow (7.4 ± 4.9 versus 6.1 ± 4.4 days respectively, p = 0.03), and lower average time intervals between menstrual periods (25.2 ± 9.6 versus 27.5 ± 11.1 days respectively, p = 0.05). A higher prevalence of symptoms of dysmenorrhea, dyspareunia, chronic pelvic pain, infertility and intestinal or urinary changes was observed in the case group when compared with the control group. The interval between the onset of symptoms and the definitive diagnosis of endometriosis was 5.2 ± 6.9 years. When comparing both groups, significant differences were not observed in the allelic and genotypic frequencies of the polymorphisms PGR +331C > T, CYP17A1 -34A > G and CYP19A1 1531G > A, even when considering the symptoms, classification and stage of the endometriosis. The combined genotype PGR +331TT/CYP17A1 -34AA/CYP19A11531AA is positively associated with endometriosis (odds ratio [OR] = 1.72; 95% confidence interval [95%CI] = 1.09–2.72).

Conclusions The combined analysis of the polymorphisms PGR-CYP17A1-CYP19A1 suggests a gene-gene interaction in the susceptibility to endometriosis. These results may contribute to the identification of biomarkers for the diagnosis and/or prognosis of the disease and of possible molecular targets for individualized treatments.
Der Patient mit Thoraxtrauma: anästhesiologisches Management
Authors: Kozian Alf , Bergmann Astrid , Hachenberg Thomas , Schilling Thomas
Published: June 2017

In der anästhesiologischen Praxis ist das Thoraxtrauma eine große Herausforderung. Verletzungen von Atemwegen, Lunge, Zwerchfell, Herz und großen thorakalen Gefäßen sind die vorherrschenden Probleme. Art und Ausmaß des chirurgischen Eingriffs sowie Wirkungen von Anästhetika und mechanischer Ventilation auf die pulmonale und kardiale Funktion sind besonders zu beachten.
Der Patient mit Thoraxtrauma: präklinische Versorgung
Authors: Hansen Michael , Hachenberg Thomas
Published: June 2017

Etwa jeder 10. Traumapatient in den Notaufnahmen weist ein stumpfes Thoraxtrauma auf, aus dem lebensbedrohliche Verletzungen wie Spannungspneumothorax oder Perikardtamponade resultieren können. Zeitkritische Diagnostik und Therapie stehen bei der Versorgung im Vordergrund. Die Durchführung lebensrettender therapeutischer Maßnahmen muss jedem Notarzt geläufig sein, und das Verletzungsmuster entscheidet über die Auswahl der Zielklinik.
Diätetische Maßnahmen bei Dialysepatienten
Authors: Thilo Florian , Stracke Sylvia , Gärtner Simone
Published: June 2017

Wenn ernährungsmedizinisch relevante Eigenheiten von Patienten mit einer dialysepflichtigen Niereninsuffizienz berücksichtigt werden, bietet die Ernährungsmedizin eine wesentliche und oftmals nicht genügend ausgeschöpfte Möglichkeit, um das Langzeitüberleben an der Dialyse zu verlängern, auf die in Zeiten knapper Spenderorgane mehr eingegangen werden sollte. Eine allzu strenge Adhärenz an einer umfassenden Nahrungsmittelrestriktion, z. B. gegenüber Eiweiß, Phosphat und Kalium, lässt sich durch die aktuelle Datenlage sicher nicht unterstützen, sodass grundsätzlich Fingerspitzengefühl und Augenmaß im Einzelfall vonnöten sind. Auch woran der Erfolg einer ernährungsmedizinischen Intervention gemessen werden sollte, bleibt weiterhin Gegenstand der Forschung.
Blutdruckeinstellung und -medikation
Authors: Hausberg Martin
Published: June 2017

Patienten mit terminaler Niereninsuffizienz weisen eine deutlich erhöhte kardiovaskuläre Morbidität und Sterblichkeit auf. Die Ursachen hierfür sind multifaktoriell, wesentlich sind erhebliche Schädigungen der arteriellen Gefäße. Die bei einem großen Teil der Dialysepatienten prävalente arterielle Hypertonie trägt zu der hohen kardiovaskulären Komplikationsrate bei. Wegen der ausgeprägten Alterationen des kardiovaskulären Systems bei Dialysepatienten besteht eine U-förmige Beziehung zwischen Blutdruck vor Dialyse und kardiovaskulärer Komplikationsrate. Blutdruckwerte zwischen 140 und 160 mmHg systolisch vor Dialysebeginn sind mit der geringsten kardiovaskulären Komplikationsrate bei Dialysepatienten assoziiert. Für die Blutdruckkontrolle und die kardiovaskuläre Prognose entscheidend ist die konsequente Einstellung der Patienten auf das Trockengewicht. Darüber hinaus sind bei vielen Patienten Antihypertensiva erforderlich. Es ist bislang nicht definitiv geklärt, ob gewisse Klassen von Antihypertensiva wie z. B. Hemmstoffe des Renin-Angiotensin-Aldosteron-Systems Vorteile gegenüber anderen Klassen von Antihypertensiva haben in Bezug auf die kardiovaskuläre Prognose.
Primary Fetal Lung Hypoplasia (PFLH): Imaging and Clinical Characteristics
Authors: Achiron Reuven , Gilboa Yinon , Salem Yishay , Jacobson Yizhak , Raviv-Zilka Lisa , Cioca Andreea , Kidron Debora , Kivilevitch Zvi
Published: June 2017

Purpose To describe in utero and postnatal imaging and clinical characteristics of primary fetal lung hypoplasia (PFLH).

Methods A retrospective review of fetuses and neonates diagnosed in one academic tertiary center during an eleven-year period.

Results 12 cases of PFLH were identified. 4 were bilateral and 8 had unilateral involvement. Prenatal sonographic characteristics, postnatal magnetic resonance imaging (MRI), computerized tomographic angiography (CTA), and histologic findings are described. 3 of the 4 bilateral cases were evaluated during fetal live. 2 were terminated and 2 died shortly after delivery. Among the 8 cases with unilateral PFLH, 7 involved the right lung and 1 the left lung. In fetuses with right hypoplasia, 5 showed characteristic features of Scimitar syndrome, while associated gastrointestinal tract (GIT) anomalies were presented in 2 cases. In this group 3 were born alive and the other 5 were terminated.

Conclusion Primary PFLH is a rare anomaly that lethal in its bilateral form and with variable prognosis in its unilateral variant. Targeted evaluation of lung vascularity and exclusion of associated anomalies, especially of the GIT, are important prognostic factors.
Medizinische Versorgung von Flüchtlingen: Chancen und Herausforderungen in Hamburg – ein Praxisbericht
Authors: Jakubowski Elke , Rau Cornelius , Quellhorst Sibylle , Sothmann Peter , Plenge-Bönig Anita , Niessen Johannes
Published: June 2017

Die stark gestiegenen Zahlen von Menschen auf der Flucht stellen insbesondere deutsche Großstädte vor Herausforderungen. Im Jahr 2015 meldeten sich in Hamburg 40 868 Schutzsuchende, von denen 22 315 aufgenommen wurden. Ziel der medizinischen Grundversorgung ist es, auf die besonderen gesundheitlichen Risiken und Bedürfnisse der Asylsuchenden einzugehen und gleichzeitig einen möglichst raschen Übergang in das Regelsystem zu ermöglichen. Öffentliche Stellen, Hilfsorganisationen und die Zivilgesellschaft arbeiten dazu Hand in Hand. In allen Hamburger Erstaufnahmeeinrichtungen werden von Übersetzern begleitete medizinische Sprechstunden in voll ausgestatteten Arztpraxiscontainern angeboten. Pro 1 000 Asylsuchenden stehen ein Arzt und eine medizinische Assistenzkraft vollzeitig zur Verfügung. Neben Honorarkräften beteiligen sich auch Mitarbeiter vertraglich eingebundener Krankenhäuser an der Versorgung. Die systematische Erhebung von Daten über den Gesundheitszustand der Asylsuchenden sowie die Stärkung des Öffentlichen Gesundheitsdienstes sind Schlüsselfaktoren, um die Versorgung zukünftig zu planen und zu verbessern. Die Schaffung eines gesünderen Lebensumfeldes und der Zugang zum medizinischen Regelsystem bieten die Chance, eine erfolgreiche Integration der Asylsuchenden in die Gesellschaft zu unterstützen.
Recommended Ideal-Gas Thermochemical Functions for Heavy Water and its Substituent Isotopologues
Authors: Simkó Irén , Furtenbacher Tibor , Hrubý Jan , Zobov Nikolai F. , Polyansky Oleg L. , Tennyson Jonathan , Gamache Robert R. , Szidarovszky Tamás , Dénes Nóra , Császár Attila G.
Published: June 2017

Accurate temperature-dependent ideal-gas internal partition functions, Qint(T), and several derived thermochemical functions are reported for heavy water, with an oxygen content corresponding to the isotopic composition of Vienna Standard Mean Ocean Water (VSMOW), and its constituent isotopologues, D216O, D217O, and D218O, for temperatures between 0 and 6000 K. The nuclear-spin-dependent partition functions are obtained by the direct summation technique, involving altogether about 16 000 measured and more than nine million computed bound rovibrational energy levels for the three molecules. Reliable standard uncertainties, as a function of temperature, are estimated for each thermochemical quantity determined, including the enthalpy, the entropy, and the isobaric heat capacity of the individual nuclear-spin-equilibrated isotopologues and of heavy water. The accuracy of the heavy-water ideal-gas Cp(T) is unprecedented, below 0.01% up to 1800 K. All the thermochemical functions are reported, in 1 K increments, in the supplementary material.
Controlling relative polymorph stability in soft porous crystals with a barostat
Authors: Mahynski Nathan A. , Shen Vincent K.
Published: June 2017

We use Monte Carlo simulations to investigate the thermodynamic behavior of soft porous crystal (SPC) adsorbents under the influence of an external barostat. We consider SPCs that naturally exhibit polymorphism between crystal forms of two distinct pore sizes. In the absence of barostatting, these crystals may be naturally divided into two categories depending on their response to stress applied by the adsorbate fluid: those which macroscopically deform and change the volume of their unit cell (“breathing”) and those which instead undergo internal rearrangements that change the adsorbate-accessible volume without modifying the unit cell volume (“gate-opening”). When breathing SPCs have a constant external pressure applied, in addition to the thermodynamic pressure of the adsorbate fluid, we find that the free energy difference between the crystal polymorphs is shifted by a constant amount over the entire course of adsorption. Thus, their relative stability may be easily controlled by the barostat. However, when the crystal is held at a fixed overall pressure, changes to the relative stability of the polymorphs tend to be more complex. We demonstrate a thermodynamic analogy between breathing SPCs held at a fixed pressure and macroscopically rigid gate-opening ones which explains this behavior. Furthermore, we illustrate how this implies that external mechanical forces may be employed to tune the effective free energy profile of an empty SPC, which may open new avenues to engineer the thermodynamic properties of these polymorphic adsorbents, such as selectivity.
Critical Evaluation of Thermodynamic Properties for Halobenzoic Acids Through Consistency Analyses for Results from Experiment and Computational Chemistry
Authors: Chirico Robert D. , Kazakov Andrei , Bazyleva Ala , Diky Vladimir , Kroenlein Kenneth , Emel′yanenko Vladimir N. , Verevkin Sergey P.
Published: June 2017

Thermodynamic properties of the twelve monohalobenzoic acids are critically evaluated through the application of computational chemistry methods for the ideal-gas phase and thermodynamic consistency assessment of properties determined experimentally and reported in the literature, including enthalpies of combustion, enthalpies of sublimation, and enthalpies of fusion. The compounds of interest are the 2-, 3-, and 4-halo isomers of fluoro-, chloro-, bromo-, and iodobenzoic acids. Computations were validated by comparison with critically evaluated entropies and heat capacities in the ideal-gas state for benzoic acid, benzene, and some halobenzenes. Experimental enthalpies of formation for 2- and 3-bromobenzoic acids, measured by well-established research groups, are mutually inconsistent and further, are shown to be inconsistent with the computations and assessment in this work. Origins of the discrepancies are unknown, and recommended values for these compounds are based on computations and enthalpies of sublimation validated, in part, by a structure-property (i.e., group-additivity) analysis. Lesser, but significant, inconsistencies between experimental and computed results are demonstrated also for 3- and 4-iodobenzoic acids. The comparison of enthalpies of formation based on the experiment and computation for the ideal-gas state of 1- and 2-chloro-, bromo-, and iodonaphthalenes provides additional support for the findings for halobenzoic acids and also reveals some anomalous results in the experimental literature for chloronaphthalenes. Computations are discussed in detail to demonstrate the approach required to obtain optimal results with modern quantum chemical methods.
Towards the Irving-Kirkwood limit of the mechanical stress tensor
Authors: Smith E. R. , Heyes D. M. , Dini D.
Published: June 2017

The probability density functions (PDFs) of the local measure of pressure as a function of the sampling volume are computed for a model Lennard-Jones (LJ) fluid using the Method of Planes (MOP) and Volume Averaging (VA) techniques. This builds on the study of Heyes, Dini, and Smith [J. Chem. Phys. 145, 104504 (2016)] which only considered the VA method for larger subvolumes. The focus here is typically on much smaller subvolumes than considered previously, which tend to the Irving-Kirkwood limit where the pressure tensor is defined at a point. The PDFs from the MOP and VA routes are compared for cubic subvolumes, V=ℓ3. Using very high grid-resolution and box-counting analysis, we also show that any measurement of pressure in a molecular system will fail to exactly capture the molecular configuration. This suggests that it is impossible to obtain the pressure in the Irving-Kirkwood limit using the commonly employed grid based averaging techniques. More importantly, below ℓ≈3 in LJ reduced units, the PDFs depart from Gaussian statistics, and for ℓ=1.0, a double peaked PDF is observed in the MOP but not VA pressure distributions. This departure from a Gaussian shape means that the average pressure is not the most representative or common value to arise. In addition to contributing to our understanding of local pressure formulas, this work shows a clear lower limit on the validity of simply taking the average value when coarse graining pressure from molecular (and colloidal) systems.
Theory of relativistic heat polynomials and one-sided Lévy distributions
Authors: Dattoli G. , Górska K. , Horzela A. , Penson K. A. , Sabia E.
Published: June 2017

The theory of pseudo-differential operators is a powerful tool to deal with differential equations involving differential operators under the square root sign. These types of equations are pivotal elements to treat problems in anomalous diffusion and in relativistic quantum mechanics. In this paper, we report on new links between fractional diffusion, quantum relativistic equations, and particular families of polynomials, linked to the Bessel polynomials in Carlitz form and playing the role of relativistic heat polynomials. We introduce generalizations of these polynomial families and point out their specific use for the solutions of problems of practical importance.
On the oscillatory hydrodynamic instability of gravitational thermal flows of liquid metals in variable cross-section containers
Authors: Lappa Marcello , Ferialdi Hermes
Published: June 2017

Natural convective flows of liquid metals in open or closed ducts and containers play a relevant role in a variety of applications in mechanical, materials, and nuclear engineering. This analysis follows and integrates the line of inquiry started in past authors’ work about the typical properties of these flows and associated hierarchy of bifurcations in rectangular geometries. The Navier–Stokes and energy equations are solved in their time-dependent and non-linear formulation to investigate the onset and evolution of oscillatory disturbances and other effects breaking the initially unicellular structure of the flow. It is shown that a kaleidoscope of oscillatory patterns is made possible by the new degree of freedom represented by the opposite inclination of the walls with respect to the horizontal direction. Even minute variations in the geometry and/or initial conditions can cause significant changes. Multiple states exist which can replace each other in given sub-regions of the space of parameters. Observed regimes include stationary convection, weakly oscillating rolls, coalescing rolls, traveling waves, and modulated (pulso-traveling) disturbances. Most interestingly, traveling waves can propagate either in the downstream or in the upstream direction according to whether the walls are converging or diverging.
Influence of plasma resistivity on peeling-ballooning modes
Authors: Zhang Y. , Huang J. , Chen S. Y. , Tang C. J.
Published: June 2017

The influence of plasma resistivity on the edge localized mode is studied with the BOUT++ code. From the linear simulation, it is found that the growth rate of the peeling-ballooning mode is mainly affected by the plasma resistance in the middle of the pedestal, while the resistance on the top or at the bottom of the pedestal plays a lesser role. Furthermore, in the nonlinear simulation, the resistance at the bottom of the pedestal has a more important effect on the energy loss in the turbulent transport phase.
Ion mass and energy selective hyperthermal ion-beam assisted deposition setup
Authors: Gerlach J. W. , Schumacher P. , Mensing M. , Rauschenbach S. , Cermak I. , Rauschenbach B.
Published: June 2017

For the synthesis of high-quality thin films, ion-beam assisted deposition (IBAD) is a frequently used technique providing precise control over several substantial film properties. IBAD typically relies on the use of a broad-beam ion source. Such ion sources suffer from the limitation that they deliver a blend of ions with different ion masses, each of them possessing a certain distribution of kinetic energy. In this paper, a compact experimental setup is presented that enables the separate control of ion mass and ion kinetic energy in the region of hyperthermal energies (few 1 eV – few 100 eV). This ion energy region is of increasing interest not only for ion-assisted film growth but also for the wide field of preparative mass spectrometry. The setup consists of a constricted glow-discharge plasma beam source and a tailor-made, compact quadrupole system equipped with entry and exit ion optics. It is demonstrated that the separation of monoatomic and polyatomic nitrogen ions (N+ and N2+) is accomplished. For both ion species, the kinetic energy is shown to be selectable in the region of hyperthermal energies. At the sample position, ion current densities are found to be in the order of 1 μA/cm2 and the full width at half maximum of the ion beam profile is in the order of 10 mm. Thus, the requirements for homogeneous deposition processes in sufficiently short periods of time are fulfilled. Finally, employing the described setup, for the first time in practice epitaxial GaN films were deposited. This opens up the opportunity to fundamentally study the influence of the simultaneous irradiation with hyperthermal ions on the thin film growth in IBAD processes and to increase the flexibility of the technique.
A detailed-balance model for thermionic emission from polyanions: The case of fullerene dianions
Authors: Concina Bruno , Lépine Franck , Bordas Christian
Published: June 2017

A detailed-balance model for thermionic emission from polyanions has been developed and applied to fullerene dianions. The specificity of this delayed decay process is electron tunneling through the repulsive Coulomb barrier (RCB). An analytical expression of the RCB is derived from electrostatic modeling of the fullerene cage. The reverse process, namely, electron attachment to the singly charged anion, is described by a hard sphere cross section weighted by the Wentzel-Kramers-Brillouin tunneling probability. This simple expression leads to a very good agreement with a measured time-resolved kinetic energy distribution of C842−. Electron binding energy is reduced when the fullerene cage size decreases, leading to an almost zero one for C702− and a negative one for C602−. Extension of the model to these systems of interest is discussed, and model outputs are compared with the experimental data from the literature.
Tunable electromagnetically induced transparency from a superconducting terahertz metamaterial
Authors: Zhang Caihong , Wu Jingbo , Jin Biaobing , Jia Xiaoqing , Kang Lin , Xu Weiwei , Wang Huabing , Chen Jian , Tonouchi Masoyoshi , Wu Peiheng
Published: June 2017

We demonstrate in this paper the tunable electromagnetically induced transparency (EIT) made from a superconducting (SC) niobium nitride (NbN) film induced by an intense terahertz (THz) field. As the variation of the incident THz field alters the intrinsic ohmic loss of the SC NbN film, the field-dependent transmittance is observed. To elaborate the role of the bright and dark modes, a hybrid coupling model is introduced to fit the experimental transmission spectra and extract the characteristic parameters of each mode. It is shown that the resonator for the bright mode is altered greatly due to strong direct coupling to the incident intense THz field, whereas the dark mode resonator has little interaction with the incident THz field via a weak near-filed coupling to the bright-mode resonator. This implies that we can partially control a mode or a part of metamaterial by introducing the intense THz field, which offers an effective manner to selectively control the electromagnetic property of the metamaterial. This work may bring many potential applications for the tunable EIT-like metamaterial.
Room temperature magnetodielectric effects in epitaxial hexaferrite BaFe10.2Sc1.8O19 thin film
Authors: Tang Rujun , Zhou Hao , Huang Jijie , Fan Meng , Wang Han , Jian Jie , Wang Haiyan , Yang Hao
Published: June 2017

The magnetodielectric (MD) effects of epitaxial hexaferrite BaFe10.2Sc1.8O19 thin film have been investigated around room temperature. The frequency dependent dielectric constant and MD analysis at room temperature show that in the low frequency regime (f <100 Hz), the MD effect exists, but it is very small. When the frequency is higher than 1 kHz, two strong MD peaks exist which should be contributed by the magnetic field dependent sample/electrode interface polarizations (1 kHz < f < 100 kHz) and electric dipole rotations in the film (f > 100 kHz), respectively. Further temperature dependent MD analysis at 1 MHz shows that the magnetic-field-induced electric dipoles dominate the MD effect below the conical magnetic transition temperature (Tcone = 306 K), while the lattice-type dipoles dominate the MD effect above Tcone. The above findings further the potential applications of multiferroic hexaferrite thin films in the magnetoelectric devices.
Polarization effects from the ambient and the gate dielectric on charge transport in polymer field-effect transistors
Authors: Kim Seohee , Dodabalapur Ananth
Published: June 2017

Charge transport in polymer field-effect transistors is hugely affected by the polarization effects, which can be originated from polar molecules in the gate dielectric and ambient air. In this letter, we investigate the polarization induced trapping enhancement by dipoles in the gate dielectric layer and ambient air at the same time through the experiment with varying conditions of surface dielectric and polar analytes in the atmosphere. We demonstrate the result from diketopyrrolopyrrole based co-polymer transistors with high mobility. Polarization effects from dipoles in the atmosphere affect mostly the shallower trap states and are relatively less severe when the interface of the gate dielectric is very polar.
Room temperature large magneto-absorption effect in Co-coated ZnO nanowires
Authors: Hsu Hua-Shu , Yeih Syun-Long , Liu Keng-Wen
Published: June 2017

We report a room temperature sizable magneto-absorption (MA) effect in Co-coated ZnO nanowires. The MA effect is energy dependent, and its value reaches a maximum in the ultraviolet region. The appearance of the MA effect strongly depends on the spin-polarized semiconductor band in ZnO, which is supposedly induced by the interfacial hybridization between the Co d-orbitals and the defect-related band near the ZnO surfaces. A two-peaked density of states related to magnetic field-dependent spin splitting has been proposed to describe the MA, which is controlled by the energy and the magnetic field.
Formation of distinctive structures of GaN by inductively-coupled-plasma and reactive ion etching under optimized chemical etching conditions
Authors: Okada N. , Nojima K. , Ishibashi N. , Nagatoshi K. , Itagaki N. , Inomoto R. , Motoyama S. , Kobayashi T. , Tadatomo K.
Published: June 2017

We focused on inductively coupled plasma and reactive ion etching (ICP–RIE) for etching GaN and tried to fabricate distinctive GaN structures under optimized chemical etching conditions. To determine the optimum chemical etching conditions, the flow rates of Ar and Cl2, ICP power, and chamber pressure were varied in the etching of c-plane GaN layers with stripe patterns. It was determined that the combination of Ar and Cl2 flow rates of 100 sccm, chamber pressure of 7 Pa, and ICP power of 800 W resulted in the most enhanced reaction, yielding distinctive GaN structures such as pillars with inverted mesa structures for c-plane GaN and a semipolar GaN layer with asymmetric inclined sidewalls. The selectivity and etching rate were also investigated.
Detection of heat produced during roughage digestion in ruminants by using infrared thermography
Authors: Salles Márcia Saladini Vieira , Silva Suelen Correa , Roma Luiz Carlos , El Faro Lenira , Bittar Carla Maris Machado , Oliveira Celso Eduardo Lins , Salles Fernando André
Published: June 2017

The present study aimed to establish the relationship of infrared thermography (IRT) with fermentation dynamics in ruminants, and to initiate the development of a method that allows associating these images with the heat produced during feed digestion. The experiment was conducted at APTA, Brazil. Twenty-four Jersey heifers (mean liveweight of 221.25 ± 59.41 kg) were subjected to the following treatments: 30R (30% corn silage and 70% concentrate), 50R (50% corn silage and 50% concentrate) and 70R (70% corn silage and 30% concentrate) in a Latin square design. The diet (corn silage + concentrate) was offered at 3% of liveweight from 0800 hours to 1400 hours. Infrared images were collected from the whole body on the left and right sides, from the eyes, from the left foreleg on the cranial and caudal side, and from the forehead. IRT images were taken at 2-h intervals for 12 h (from 0600 hours to 1800 hours) and 24 h (0600 hours of the following day) after the beginning of feeding and so on. Physiological parameters were obtained at the same time as the IRT were taken. Ruminal parameters were collected after 4 h of feeding. The thermograms of the right (P < 0.001) and left flank (P < 0.001) differed among sampling times, with an increase in temperature until 1400 hours and a reduction thereafter. The temperatures on the right (P = 0.037) and left (P = 0.017) flank were higher in animals consuming the 50R diet and lower in those consuming the 70R diet. When the 50R diet was offered, the heifers exhibited higher dry-matter intake (P < 0.001), neutral detergent fibre (P < 0.001), non-fibrous carbohydrates (P < 0.001) and total digestible nutrients (P < 0.001). A decrease in the concentrations of butyric acid (P = 0.042), isobutyric acid (P = 0.001), isovaleric acid (P = 0.019) and ammonia nitrogen (P = 0.001) in the rumen fluid of heifers was observed with an increasing dietary roughage level. Infrared thermography was able to detect differences in the body temperature of animals associated with different fibre proportions in the diets. However, the magnitude of these differences was small and further research is needed to investigate the application of IRT to the detection of possible differences in the body temperature of ruminants as part of the digestive process.