bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydraulic Simulation Analysis of Sonic Drilling Hydraulic Vibration Head
Authors: Shan Fan , Chen Zeping
Published: January 2019

The hydraulic vibration head is the core component of sonic drilling rig, and the performance of its hydraulic system influences the technology of sonic drilling directly. The structure and hydraulic system of the hydraulic vibration head are designed, and the AMESim model of the hydraulic system is established in the paper. The hydraulic vibration system is simulated and analyzed to find out the influence rule of vibration frequency on the system performance. The results show that the larger the vibration frequency f is, the smaller the amplitude H is, and the displacement response of the vibrating piston approximates the sine curve.The velocity and acceleration of the vibrating piston accordingly increased, and the exciting force F of the vibrating piston increased significantly.
Implicit Euler Implementation of Twisting Controller and Super-Twisting Observer without Numerical Chattering: Precise Quasi-Static MEMS Mirrors Control
Authors: Luo Dong , Xiong Xiaogang , Jin Shanhai , Chen Wei
Published: January 2019

The quasi-static operations of MEMS mirror are very sensitive to undesired oscillations due to its very low damping. It has been shown that closed-loop control can be superior to reduce those oscillations than open-loop control in the literature. For the closed-loop control, the conventional way of implementing sliding mode control (SMC) algorithm is forward Euler method, which results in numerical chattering in the control input and output. This paper proposes an implicit Euler implementation scheme of super twisting observer and twisting control for a commercial MEMS mirror actuated by an electrostatic staggered vertical comb (SVC) drive structure. The famous super-twisting algorithm is used as an observer and twisting SMC is used as a controller. Both are discretized by an implicit Euler integration method, and their implementation algorithms are provided. Simulations verify that, as compared to traditional sliding mode control implementation, the proposed scheme reduces the chattering both in trajectory tracking output and control input in presence of model uncertainties and external disturbances. The comparison demonstrates the potential applications of the proposed scheme in industrial applications in terms of feasibility and performance.
Current Decoupling and Controller Design for Induction Motors Based on Neutral Delay System
Authors: Wang Guofang , Pan Yuedou , Li Yongliang
Published: January 2019

In the AC power transmission system, in order to reduce the loss of switching devices, the switching frequency of the traction converter is generally low, and a large digital control delay will occur, which will aggravate the cross coupling between the excitation component and the torque component of the stator current of the motor, resulting in poor system performance. In order to solve this problem, based on the theory of neutral time-delay system and the rotor flux-oriented model of induction motors, the mathematical model of neutral-type time-delay system for induction motors is established, and a neutral current controller with current decoupling control is designed. The decoupling control of the stator current reduces the influence of the digital control delay on the system performance. The simulation results show that the induction motor system with a neutral current controller has the advantages of small coupling, rapid response, and strong robustness. Explains the feasibility of the designed current controller.
Defect Detection and Three Dimensional Reconstruction of Castings
Authors: Jing Liu
Published: January 2019

There are defects inevitably in the production of castings. These defects will short the life of castings. In this paper, defects of the castings are detected by industrial CT non-destructive testing method and a series of CT slice images are obtained. Then edge extraction is realized through the Canny operator and the defects in the castings are found. Finally, surfaces and its internal defects are reconstructed for the casting based on secondary development of Unigraphics software and Visual Studio 2013. Experiments show that internal defects of the castings can be extracted by the Canny operator effectively. Internal position and shape of defects can be observed directly by three dimensional reconstruction.
Deployment Kinematic Analysis and Control of a New Hoop Truss Deployable Antenna
Authors: Zihan Sun , Ding Yankang , Zhang Yiqun , Yang Dongwu , Li Na
Published: January 2019

Firstly, based on the structural characteristics of a new type of hoop truss deployable antenna, this paper derives the motion transformation relation between two hoop modules by using the method of coordinate transformation, and establishes the general model for deployment kinematic analysis, which can be applied to analyze the position, velocity and acceleration of any point on the structure. Secondly, according to the relation between the driving cable and the hoop module, the motion planning of the hoop module is transformed into the motion control of the driving cable, which can realize the deploying position control of the antenna. Finally, numerical simulations show the control method can make the antenna smoothly deploy following the specified deployable motion.
Le diagnostic préimplantatoire (DPI) à l’ère de la médecine prédictive
Authors: Baertschi Bernard
Published: January 2019

Le séquençage à haut débit est en train de révolutionner les différents diagnostics génétiques et notamment le diagnostic préimplantatoire (DPI), ouvrant les portes à une médecine prédictive de plus en plus performante. Le DPI n’est pas lui-même nouveau, et les différentes législations s’en sont saisies depuis une vingtaine d’années ; les comités nationaux d’éthique ont de leur côté largement débattu des tests anténataux dans le cadre de l’assistance médicale à la procréation. Cet article examine les travaux de ces comités concernant le DPI dans trois États, la France, la Belgique et la Suisse, afin de mettre en lumière leurs similitudes et leurs différences. Le sujet a par ailleurs été soulevé et discuté dans le cadre des États généraux de la bioéthique qui se sont déroulés cette année en France et, vu les progrès diagnostiques réalisés depuis peu, ils se sont fait l’écho de certaines demandes de la société civile. Toutefois, en France, c’est la prudence qui continue de dominer.
Quorum sensing et quorum quenching : Comment bloquer la communication des bactéries pour inhiber leur virulence ?
Authors: Mion Sonia , Rémy Benjamin , Plener Laure , Chabrière Éric , Daudé David
Published: January 2019

La plupart des bactéries utilisent un système de communication, le quorum sensing, fondé sur la sécrétion et la perception de petites molécules appelées autoinducteurs qui leur permettent d’adapter leur comportement en fonction de la taille de la population. Les bactéries mutualisent ainsi leurs efforts de survie en synchronisant entre elles la régulation de gènes impliqués notamment dans la virulence, la résistance aux antimicrobiens ou la formation du biofilm. Des méthodes ont vu le jour pour inhiber cette communication entre bactéries et limiter leurs effets nocifs. Des inhibiteurs chimiques, des anticorps ou encore des enzymes capables d’interférer avec les autoinducteurs ont été développés et se sont montrés efficaces pour diminuer la virulence des bactéries à la fois in vitro et in vivo. Cette stratégie, appelée quorum quenching, a également montré des effets synergiques avec des traitements antibactériens classiques. Il permettrait notamment d’augmenter la sensibilité des bactéries aux antibiotiques. Ceci constitue une piste thérapeutique prometteuse pour lutter contre les infections bactériennes et limiter les conséquences de l’antibiorésistance.
Les lois françaises de bioéthique
Authors: Thouvenin Dominique
Published: January 2019

médecine/sciences (m/s) a, tout au long de son existence, accompagné les nombreux débats qui ont agité la communauté scientifique et médicale concernant les questions de bioéthique posées par les bouleversements majeurs que les avancées de la recherche biomédicale ont introduits dans les pratiques thérapeutiques. La révision des lois de bioéthique est désormais proche et notre revue a voulu éclairer nos lectrices et nos lecteurs en leur proposant des regards multiples et croisés sur différents thèmes que cette révision aborde. Regard d’une juriste sur l’histoire de ces lois, leur genèse et les débats qui ont présidé à leur évolution jusqu’à ce jour, regard d’une sociologue sur certains des débats qui ont animé les États généraux de 2018, regard d’un philosophe penseur du « moment » et s’interrogeant sur ce que signifie la bioéthique, et, enfin, regards comparatifs de collègues étrangers mais francophones (un grand merci à ces auteur[e]s !) qui nous éclairent sur la façon dont certaines des thématiques faisant l’objet de ces lois dans notre pays sont abordées dans d’autres pays. Enfin, nous essaierons, autant que faire se peut, d’accompagner ces manuscrits de Nouvelles et de Synthèses portant sur les dernières avancées des sciences biologiques et médicales susceptibles d’éclairer les débats en leur apportant des données scientifiques et cliniques.

Marie Gaille et la Rédaction
Notfallversorgung und Erstbehandlung epileptischer Anfälle im Erwachsenenalter
Authors: Schiefer Johannes , Surges Rainer
Published: January 2019

Suspected epileptic seizures are a frequent cause of emergency hospital care. After single seizures, the emergency management includes safety measures and diagnostic efforts to distinguish epileptic seizures from its manifold mimics and to possibly detect acute causes of epileptic seizures. Convulsive status epilepticus requires rapid anticonvulsant treatment according to established protocols and diagnostics to rule out underlying acute brain diseases. After a first seizure, typical EEG- and MRI findings may indicate an elevated recurrence risk, thereby justifying the ultimate diagnosis of epilepsy and initiation of anticonvulsant therapy. This article reviews the recent definition of epilepsy, summarizes clinical characteristics of epileptic seizures and its mimics and provides an overview of established therapies of single convulsive seizures, convulsive status epilepticus and early care of adults after first unprovoked seizures.
Keuchhusten, die vergessene Krankheit
Authors: Abermann Christoph , Müller Susanne
Published: January 2019

Keuchhusten wird bei Patienten nach Erfahrung des Autors häufig übersehen, da viele Ärzte anscheinend nicht mehr mit dem Auftreten der Erkrankung rechnen. Die Inzidenz des Keuchhustens ist jedoch ansteigend, und selbst eine erfolgte Impfung oder eine früher durchgemachte Erkrankung sind keine Garantie für eine lang andauernde Schutzwirkung. Ziel dieses Artikels ist daher, einen Überblick über die Erkrankung, ihre Diagnostik und Therapiemöglichkeiten zu geben, sowie auf mögliche Gründe hinzuweisen, warum der Keuchhusten oft übersehen wird. Anhand mehrerer Fälle aus meiner Praxis wird schließlich die homöopathische Behandlung des Keuchhustens näher betrachtet.
Schwere Tirofiban-induzierte Thrombozytopenie und thrombotische Mikroangiopathie nach perkutaner Koronarintervention
Authors: Nettersheim Felix , Hohmann Christopher , Pfister Roman , Michels Guido
Published: January 2019

Anamnese und klinischer Befund Ein 76-jähriger Patient wurde bei Nicht-ST-Streckenhebungsinfarkt (NSTEMI) einer Koronarangiografie zugeführt.

Untersuchungen und Diagnose Bei Verschluss der rechten Herzkranzarterie erfolgte eine Koronarintervention mit Stentimplantation. Bei hoher Thrombus-Last wurde eine Therapie mit Tirofiban initiiert. Im kurzzeitigen Verlauf entwickelte der Patient eine hämodynamische Instabilität, Hämoptysen sowie einen erheblichen Thrombozyten-Abfall.

Therapie und Verlauf Die Tirofiban-Therapie wurde sofort beendet. Unter Volumentherapie gelang eine hämodynamische Stabilisierung und die Hämoptysen sistierten. Der Patient erhielt ein Thrombozyten-Konzentrat und Prednisolon, woraufhin sich die Thrombozyten stabilisierten. Am Folgetag kam es zu einer erheblichen Lungenblutung mit asphyktischem Herzkreislauf-Stillstand und 2 Tage später zu einem erneuten Thrombozyten-Abfall. Trotz Normalisierung der Thrombozyten nach erneuter Transfusion verstarb der Patient an den Folgen einer Sepsis.

Folgerung Die Thrombozytopenie ist eine seltene, aber potenziell schwerwiegende Komplikation der Tirofiban-Therapie. Empfohlene Maßnahmen sind die sofortige Beendigung der Medikation, der Ausschluss möglicher Differenzialdiagnosen sowie gegebenenfalls die Substitution von Thrombozyten.
Secale cornutum
Authors: Allen H. , Holzapfel mit einer Einleitung von
Published: January 2019

Es werden die Prüfungssymptome im Kopf-zu-Fuß-Schema der fragmentarischen Secale-cornutum-Prüfung von H. C. Allen vorgelegt.
Role of Vasopressin Receptor 2 and 3 in ACTH-Secreting Tumors and
their Potential Therapeutic Implications
Authors: Yang Jia , Yang Yehong , Wang Yongfei , Zhang Shuo , Cheng Haixia , Wang Shuyang , Ge Liang , Li Yiming , Ye Hongying
Published: January 2019

Purpose We investigated the expression of vasopressin receptor 2 and
3 on corticotrophin tumor cells, their role in regulating ACTH secretion,
and their potential therapeutic implications.

Methods We retrospectively assessed 52 hospitalized patients with
pathologically confirmed ACTH-secreting tumors. The expression of
vasopressin receptor 2 and 3 was explored via qualitative and quantitative
immunohistochemistry analyses. The role of vasopressin receptors in
regulating ACTH secretion was further studied in the AtT-20 cell line.

Results Among 50 cases of pituitary corticotrophin adenoma, 31 were
vasopressin receptor 2 positive, 38 were vasopressin receptor 3 positive,
and 24 were both vasopressin receptor 2 and 3 positive. Two patients with
ectopic ACTH syndrome were vasopressin receptor 3 positive, and one was also
vasopressin receptor 2 positive. In 12 patients who underwent bilateral
inferior petrosal sinus sampling before surgery, the central ACTH increment
ratio after desmopressin stimulation was correlated with vasopressin
receptor 2 but not with vasopressin receptor 3 staining intensity. In an in
vitro study, the expression of both vasopressin receptor 2 and 3 on AtT-20
cells was confirmed. The vasopressin receptor 2 antagonist Tolvaptan
inhibited desmopressin-induced ACTH secretion in a dose-dependent
manner.

Conclusions Both vasopressin receptor 2 and 3 are expressed in
ACTH-secreting tumors. Vasopressin receptor 2 rather than vasopressin
receptor 3 is the primary receptor that seems to mediate the ACTH response
in corticotrophin tumors. A vasopressin receptor 2 antagonist can inhibit
ACTH secretion induced by desmopressin in AtT-20 cells.
Efficient Synthesis of Several Natural Oligostilbenes from the ­Biomimetic Oxidation of Brominated Isorhapontigenin
Authors: Guan Xingchao , Liu Meijie , Shao Zhibo , Li Hongpeng , Ran Lu , Li Wenling
Published: January 2019

This study extensively investigated the regioselective oxidative coupling reactions of 5-bromoisorhapontigenin catalyzed by ­FeCl3·6H2O or HRP/H2O2 in different solvent systems and the distinct reductive debromination of the isolated dimeric coupling intermediates. Natural (±)-bisisorhapontigenin A and (±)-lehmbachol A and B were efficiently prepared. (±)-Gnetuhainin I, (±)-gnemontanin E, (±)-7-O-ethylgnetuhainin I, and (±)-gnemontanin F were synthesized for the first time.
Clinical Short-Term Outcome and Hemodynamic Comparison of Six Contemporary Bovine Aortic Valve Prostheses
Authors: Hartrumpf Martin , Kuehnel Ralf-Uwe , Schroeter Filip , Haase Robert , Laux Magdalena L. , Ostovar Roya , Albes Johannes M.
Published: January 2019

Background Conventional stented valves (CV) remain gold standard for aortic valve disease. Bovine prostheses have been improved and rapid deployment valves (RDV) have arrived in the recent decade. We compare clinical and hemodynamic short-term outcome of six bovine valves.

Methods We retrospectively evaluated 829 consecutive patients (all-comers) receiving bovine aortic valve replacement (AVR). Four CV from different manufacturers (Mitroflow, Crown, Perimount, Trifecta) and two RDV (Perceval, Intuity) were compared in terms of pre-, intra-, and postprocedural data. A risk model for mortality was created.

Results All valves reduced gradients. From 23 mm, all CV showed acceptable gradients. Twenty-one millimeter Mitroflow/Perceval and 19 mm Crown showed above-average gradients. As baseline data differed, we performed propensity matching between aggregated isolated CV and RDV groups. Cardiopulmonary bypass (CPB), clamp, and surgery times were shorter with RDV (87.4 ± 34.0 min vs 111.0 ± 34.2, 54.3 ± 21.1 vs 74.9 ± 20.4, 155.2 ± 42.9 vs 178.0 ± 46.8, p < 0.001). New pacemaker rate (10.1 vs 1.3%, p = 0.016) and the tendency toward neurologic events (8.9 vs 2.5%, p = 0.086) were higher using RDV, induced mainly by the Perceval. Early mortality was equal (2.5 vs 1.3%, p = 0.560). Revision for bleeding, dialysis, blood products, length-of-stay, gradients, and regurgitation was also equal. Risk analysis showed that low valve size, low ejection fraction, endocarditis, administration of red cells, and prolonged CPB time were predictors of elevated mortality.

Conclusion Isolated bovine AVR has low mortality. Valves ≥ 23 mm show comparable gradients while the valve model matters < 23 mm. RDV should be used with care. Procedure-related times are shorter than those of CV but pacemaker implantation and neurologic events are more frequent (Perceval). Early mortality is low and valve performance comparable to CV.
Integration of Postcoordination Content into a Clinical Interface Terminology to Support Administrative Coding
Authors: Rose Eric , Rube Steven , Kanter Andrew , Cardwell Matthew , Naeymi-Rad Frank
Published: January 2019

Background Clinical interface terminologies (CITs) consist of terms designed for clinical documentation and, through mappings to standardized vocabularies, to support secondary uses of patient data, including clinical decision support, quality measurement, and billing for health care services. The latter purpose requires maps to administrative coding systems, such as the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), for diagnoses in the United States.

Objectives The transition from ICD-9-CM to ICD-10-CM posed a challenge to CIT users due to the substantially increased details in ICD-10-CM. To address this, we developed a content layer within a CIT that provides postcoordination prompts for the details required for accurate ICD-10-CM coding.

Methods We developed content to support prompting for and capture of additional information specified by the user in a single, clinically relevant term that is added to the patient's record, and whose mapping to other coding systems (like Systematized Nomenclature of Medicine—Clinical Terms [SNOMED CT]) reflects the details added during postcoordination. We worked with clinical information system developers to incorporate this into user interfaces, and with end-users to refine the design.

Results While the prompts were designed around the precoordinated elements implicit in ICD-10-CM, irregularities in ICD-10-CM required some additional design measures, such as providing postcoordination options that interpolate gaps in ICD-10-CM to avoid user confusion. The system we describe has been implemented by ∼30,000 health care provider organizations, with content that covers the vast majority of encounter diagnoses. User feedback has been largely positive, though concerns have been raised about expanding postcoordination content beyond that required for ICD-10-CM coding.

Conclusion We have demonstrated the design and development of what, to our knowledge, is the first system that uses postcoordination to capture ICD-10-CM-relevant details in a CIT while also reflecting the details added by the user in maps to other vocabularies.
Automated Generation of CONSORT Diagrams Using Relational Database Software
Authors: O'Leary Teresa , Weiss June , Toll Benjamin , Brandt Cynthia , Bernstein Steven
Published: January 2019

Background Investigators conducting prospective clinical trials must report patient flow using the Consolidated Standards of Reporting Trials (CONSORT) statement. Depending on how data are collected, this can be a laborious, time-intensive process. However, because many trials enter data electronically, CONSORT diagrams may be generated in an automated fashion.

Objective Our objective was to use an off-the-shelf software to develop a technique to generate CONSORT diagrams automatically.

Methods During a recent trial, data were entered into FileMaker Pro, a commercially available software, at enrollment and three waves of follow-up. Patient-level data were coded to automatically generate CONSORT diagrams for use by the study team.

Results From August 2012 to July 2014, 1,044 participants were enrolled. CONSORT diagrams were generated weekly for study team meetings to track follow-ups at 1, 6, and 12 months, for 960 (92%), 921 (90%), and 871 (88%) participants who were contacted or deceased, respectively. Reasons for loss to follow-up were captured at each follow-up.

Conclusion CONSORT diagrams can be generated using a standard software for any trial and can facilitate data collection, project management, and reporting.
Pseudoaneurysms of the Peripheral Arteries
Authors: Henry Jon , Franz Randall
Published: January 2019

Peripheral arterial pseudoaneurysm, while relatively rare, are encountered by most vascular specialists. This review evaluates the epidemiology, diagnosis, natural history, and treatment of pseudoaneurysm in the peripheral arteries. Most of this review concentrates on iatrogenic peripheral pseudoaneurysms, but pseudoaneurysms of other etiologies will also be discussed.
National Analysis of Risk Factors for Nasal Fractures and Associated Injuries in Trauma
Authors: Pham Tiffany T. , Lester Ellen , Grigorian Areg , Roditi Rachel E. , Nahmias Jeffry T.
Published: January 2019

Nasal fractures account for up to 58% of facial fractures. However, the literature characterizing associated injuries and risk factors for nasal fractures is sparse and is mostly composed of single-center experiences. This study sought to provide a large descriptive analysis and identify associated injuries and risk factors for nasal fractures in trauma using a national database. A retrospective analysis of the National Trauma Data Bank (NTDB) from 2007 to 2015 was performed. Patients ≥18 years of age with nasal fractures were included. A multivariable logistic regression model was used to identify predictors for nasal fracture in trauma. Of 5,494,609 trauma patients in the NTDB, 255,533 (4.6%) had a nasal fracture. Most were male (74.8%) with a mean age of 45.6 years. Blunt trauma accounted for 90.5% of fractures, with motor vehicle accident being the most common mechanism (27.5%). Closed fractures occurred in 93.0% of patients. Concomitant injuries included traumatic brain injury (TBI; 56.9%), malar/maxillary fracture (27.9%), and open wound of the face (38.6%) and nose (9.5%). Of all patients, 10.1% underwent closed or open reductions at index hospitalization. The strongest associated injuries with nasal fracture included open wound of the nose (odds ratio [OR]: 8.71, 95% confidence interval [CI]: 8.49–8.94, p < 0.001), epistaxis (OR: 5.26, 95% CI: 4.59–6.02, p < 0.001), malar/maxillary fracture (OR: 4.38, 95% CI: 4.30–4.45, p < 0.001), and orbital fracture (OR: 3.99, 95% CI: 3.91–4.06, p < 0.001). Nasal fractures are common traumatic injuries with more than 90% occurring by blunt mechanism and over half suffering from a concomitant TBI. The strongest associated injury with nasal fracture is an open wound of the nose.
Combined impact of compression ratio and re-circulated exhaust gas on the performance of a biogas fueled spark ignition engine
Authors: Chaudhari Ashish J. , Hotta Santosh K. , Sahoo Niranjan , Kulkarni Vinayak
Published: January 2019

The usage of biogas as a potential fuel in a spark ignition (SI) engine is the theme for the present study. The exhaust gas recirculation (EGR) is a significant technique for improving the performance of the SI engine. Thus, the novelty of the experimental investigations lies in implementing the EGR technique for emission control of the biogas-fueled engine. The raw biogas (52% methane and 47% carbon dioxide), obtained from a biogas digester (using cow dung as the source), was the engine fuel for a four stroke, water cooled, variable compression ratio SI engine set-up. Here, the engine performance and emission related parameters were measured. When operated in the raw biogas mode at an optimum spark timing of 45 °CA before the top dead center, the engine produced maximum torques of 11 N m, 14 N m, and 16 N m for compression ratios 8, 9, and 10, respectively. The effect of different EGR rates on the emission control was also investigated. The net heat release rate without EGR was found to be 22.623J/°CA at 368 °CA, which further reduced to 14.233 J/°CA at 386 °CA for EGR10. Moreover, it was clearly evident that low EGR rates (below 10%) were effective in reducing NOX significantly, with minor compromise in power and brake specific fuel consumption. But the emissions of hydrocarbon and carbon monoxide were found to be higher with the increase in EGR. The operation of the engine with medium or heavy EGR rates resulted in issues related to intense pressure fluctuations and large cycle-to-cycle variation in performance. Thus, the present investigations recommend the use of low EGR (below 10%) in a biogas-based engine for lower NOX emission and better fuel efficiency.
On phase steepening as an intense plasma heating mechanism
Authors: Campos L. M. B. C.
Published: January 2019

A new physical mechanism of the intense plasma heating is introduced, which may be designated as phase steepening: (i) it applies to velocity and/or magnetic field scaling like a power of the distance with a complex exponent; (ii) the imaginary part the exponent corresponds to a phase with a logarithmic singularity, which leads to oscillations with increasing diverging steepness; and (iii) the steep gradients, even with finite or moderately decaying amplitude, lead to intense dissipation and heating. The physical process of phase steepening is identified in a quite general case of steady magnetohydrodynamics of an incompressible fluid subject to rotation and gravity, in the combined presence of three dissipation mechanisms: electrical resistance, fluid viscosity, and thermal conduction (Fig. 1). The exact analytical solution of the problem leads to 13 cases, one of which suggests the possibility of phase steepening, with conditions that are not fully satisfied. Most of the cases assume the existence of an axisymmetric flow source or sink at the axis and also of a split-monopole magnetic field decaying like the inverse of the radial distance, with opposite directions in different angular sectors, so that the total magnetic flux across a cylindrical surface is zero. The possibility remains that all conditions for phase steepening could be met in other physical conditions.
Thermal-wave resonant cavity signal processing
Authors: Gu Caikang , Shen Jun , Zhou Jianqin , Michaelian Kirk H. , Gieleciak Rafal , Astrath Nelson G. C. , Baesso Mauro L.
Published: January 2019

The thermal-wave resonant cavity (TWRC) technique has been used for thermal diffusivity measurements by many researchers. This study aims to reduce the uncertainty associated with TWRC signal processing (curve fitting) by means of numerical simulation and experimental verification. Simulations show that the plot of signal amplitude versus cavity length can be fitted to a simplified model reported previously when the initial fitting position is at least twice the thermal-wave diffusion length (2 μg), and that the uncertainty caused by different end positions is negligible in the range of 6–10 μg. Upon consideration of the simulation results, signal-to-noise ratio, and clearly defined amplitude curve shape, fitting ranges of about 2.2–8.0 μg and 2.2–8.7 μg were chosen for the experimental data. Thermal diffusivity values (1.438 ± 0.001) × 10−7 and (1.436 ± 0.001) × 10−7 m2 s−1, respectively, were obtained for distilled water, in excellent agreement with the accepted literature value. The ratio of standard deviation to the mean value is smaller than 0.07%, one order of magnitude lower than typical results reported in the literature. Similar simulation results were obtained for air and methanol as intra-cavity samples.
Thermal insulation performance of an advanced photovoltaic vacuum glazing: A numerical investigation and simulation
Authors: Chen Benyuan , Lv Hui , Liao Jun , Dong Shijie , Cheng Chunfu , Lv Qinghua , Li Jin , Su Yuehong , Riffat Saffa
Published: January 2019

Structural details of an advanced laminated PV (photovoltaic) vacuum glazing are illustrated. The glazing design features low heat gain or loss, while the sandwiched PV film generates electricity and allows daylight and vision. The thin vacuum gap and glass sheets make it slimmer and lighter than conventional designs. Aerogel support pillars and epoxy resin edge seals minimise conductive heat transfer and further reduce the weight of the window. The thermal insulation performance of the PV vacuum glazing is numerically investigated. All the three heat transfer mechanisms are considered in the COMSOL modelling. During the modelling of radiation in participating media, the optical properties of low-e (low-emissivity) and PV coating are considered and a boundary condition for translucence is re-customized in particular. For the verification of the modeling accuracy, a simplified vacuum glazing model is adopted first. The simulation results are consistent with the thermal performance data report of a vacuum glazing manufacturer. Subsequently, comprehensive simulation results with different configurations of the PV vacuum glazing are presented and discussed. Retrofitting of steel pillars with aerogel pillars for conventional vacuum glazing can yield a decrease of 0.3255 W/m2 K in the overall U-value and a decrease of 0.2559 W/m2 K in the central U-value. Besides, the thermal resistances of the laminated structure are calculated layer by layer. Moreover, the influence of the radiative parameters of the PV film on the thermal performance of the glazing is assessed. On the other hand, the simulation of the PV vacuum glazing under solar radiation is carried out to evaluate its working temperature.
A new approach to braided monoidal categories
Authors: Zhang Tao , Wang Shuanhong , Wang Dingguo
Published: January 2019

Let H be a Hopf quasigroup over k possessing an adjoint quasiaction. Then we first show that if M is any right H-comodule and N is any right H-quasimodule such that τN,M2=idN⊗M, where τN,M : N ⊗ M → M ⊗ N is a favourable map, then we have H = k as a generalization of Pareigis’ theorem [J. Pure Appl. Algebra 155, 91 (2001)]. Then we mainly give a new approach to a braided monoidal category by generalizing one of Schauenburg’s main results [Schauenburg, P., J. Algebra 169, 874–890 (1994)] in the setting of Hopf quasigroups introduced by Klim and Majid [J. Algebra 323, 3067–3110 (2010)]. This yields new sources of braidings which provide solutions to the Yang-Baxter equation playing an important role in various areas of mathematics.
Synchrotron-based infrared spectroscopy of formic acid: Confirmation of the reassignment of Fermi-coupled 8 μm states
Authors: Hull Killian , Wells Tyler , Billinghurst Brant E. , Bunn Hayley , Raston Paul L.
Published: January 2019

The empirically derived assignment of the strongly interacting 51 and 92 vibrational states of trans-HCOOH has recently been reassigned on the basis of anharmonic frequency calculations, and this, in turn, affects the assignment of many higher energy states. Here, we investigate the high-resolution synchrotron-based torsional spectrum of trans-HCOOH, and find experimental confirmation that the proposed reassignment is indeed correct, i.e., that 92 is in fact lower in energy than 51. This is largely based on examining the intensity ratio of transitions with the same rotational quantum numbers between the 92-91 and 51-91 hot bands, which indicates that the 51 [92] state has ∼31% 92 [51] character. We also examined the torsional spectrum of trans-HCOOD, and find that the intensity ratios are consistent with 92 instead being higher in energy than 61 (which is analogous to 51 in trans-HCOOD), as previously determined from higher energy spectra.
BiVO4 as highly efficient host for near-infrared to visible upconversion
Authors: Regmi Chhabilal , Kshetri Yuwaraj K. , Jeong Sang Hoon , Lee Soo Wohn
Published: January 2019

BiVO4 is a well-known visible-light-active semiconductor photocatalyst. Here, we report BiVO4 as a highly efficient host material for near-infrared (NIR) to visible frequency upconversion. Various lanthanide ions (Yb, Er, and Tm) doped BiVO4 upconversion phosphors were successfully synthesized through a facile microwave hydrothermal method. As-synthesized samples exhibit intense green, red, and NIR upconversion emissions under 980 nm excitation at power density as low as 0.02 W cm−2. The quantum efficiency for Yb, Er, and Tm triply doped BiVO4 under 2.0 W cm−2 was as high as 2.19% in the 500–850 nm range. Moderately low phonon energy (824 cm−1) of BiVO4 was found to be responsible for the existence of long-lived metastable energy levels leading to efficient upconversion emissions. Potential application of the material for producing latent images and security printing has been demonstrated. The high quantum efficiency of BiVO4 offers an opportunity to develop alternative upconversion materials based on the BiVO4 host for various optical applications.
Guiding robust valley-dependent edge states by surface acoustic waves
Authors: Wang Zhen , Liu Fu-Kang , Yu Si-Yuan , Yan Shi-Ling , Lu Ming-Hui , Jing Yun , Chen Yan-Feng
Published: January 2019

Recently, the concept of valley pseudospin, labeling quantum states of energy extrema in momentum space, has attracted enormous attention because of its potential as a new type of information carrier. Here, we present surface acoustic wave (SAW) waveguides which utilize and transport valley pseudospins in two-dimensional SAW phononic crystals. In addition to a direct visualization of the valley-dependent modes excited from the corresponding chiral sources, the backscattering suppression of SAW valley-dependent edge modes transport is observed in sharply curved interfaces. By means of band structure engineering, elastic wave energy in the SAW waveguides can be transported with remarkable robustness, which is very promising for new generations of integrated solid-state phononic circuits with great versatility.
Nonlinear saturation of kinetic ballooning modes by zonal fields in toroidal plasmas
Authors: Dong G. , Bao J. , Bhattacharjee A. , Lin Z.
Published: January 2019

Kinetic ballooning modes (KBMs) are widely believed to play a critical role in disruptive dynamics as well as turbulent transport in magnetic fusion and space plasmas. While the nonlinear evolution of the ballooning modes has been proposed as a mechanism for “detonation” in various scenarios such as the edge localized modes in tokamaks, the role of the kinetic effects in such nonlinear dynamics remains largely unexplored. In this work, global gyrokinetic simulation results of KBM nonlinear behavior are presented. Instead of the finite-time singularity predicted by ideal magnetohydrodynamic theory, the kinetic instability is shown to develop into an intermediate nonlinear regime of exponential growth, followed by a nonlinear saturation regulated by spontaneously generated zonal fields. In the intermediate nonlinear regime, rapid growth of localized current sheets, which can induce magnetic reconnection, is observed.
Realization of entire-space electromagnetic wave manipulation with multifunctional metasurface
Authors: Zhang C. , Cao X. Y. , Gao J. , Li S. J. , Yang H. H. , Li T.
Published: January 2019

In this paper, we present a multifunctional metasurface (MS) to manipulate electromagnetic wave in the entire-space. First, we propose a MS unit structure which consists of four elaborately designed metal patterns separated by three substrate layers. Through changing the structures of metal layer 2 and layer 4, two different 1-bit units for transmission and reflection modes are obtained. By combining these two working modes together, the proposed MS can adjust the transmitted and reflected phases respectively in the upper and lower half-spaces. Thus we demonstrate some intriguing electromagnetic modulation functions in the entire-space, such as beam forming, anomalous reflection and diffusion. The simulated and experimental results prove that our method offers a feasible strategy for multifunctional MS design and other related practical applications.
Darcy Forchheimer nanofluid thin film flow of SWCNTs and heat transfer analysis over an unsteady stretching sheet
Authors: Nasir Saleem , Shah Zahir , Islam Saeed , Bonyah Ebenezer , Gul Taza
Published: January 2019

This article analyzes the Darcy Forchheimer 2D thin film fluid of nanoliquid. Flow of nanoliquid is made due to a flat unsteady stretchable sheet. In nanoliquids, nanomaterial is in form of CNTs (carbon nanotubes). Also, in present analysis, single walled carbon nanotubes (SWCNTs) are accounted as nanoparticles. The classical liquid ‘water’ is treated as based liquid. The flow in permeable region is characterized by Darcy–Forchheimer relation. Heat transport phenomena are studied from convective point of view. The transformation of partial differential set of equations into strong ordinary differential frame is formed through appropriate variables. Homotopy Analysis Method (HAM) scheme is executed for solving the simplified set of equations. In addition, a numerical analysis (ND-Solve) is utilized for the convergence of the applied technique. The influence of some flow model quantities like Pr (Prandtl number), λ (unsteadiness factor), k (porous medium factor), F (Darcy-porous medium factor) on liquid velocity and thermal field are scrutinized and studied through sketches. Certain physical factors like f″(0) (friction factor coefficient) and −θ′(0) (rate of heat transport) are first derived and then presented through tables.
Comparative Study of Different Electrochemical Techniques for the Preparation of Supported Pt-Ru Catalysts
Authors: Castagna Rodrigo M. , Sieben Juan Manuel , Alvarez Andrea E. , Duarte Marta M. E.
Published: January 2019

Bimetallic Pt-Ru particles supported on glassy carbon rods were synthesized by simultaneous electrochemical deposition. Pt-Ru alloy particles were deposited from a dilute aqueous acid solution of chloroplatinic acid and ruthenium trichloride by different electrochemical techniques: (i) coulostatic deposition at constant potential; (ii) double potentiostatic steps; and (iii) multiple cycles of potentiostatic pulses. It was found that particle size distribution, and the morphology and composition of the deposits strongly depend on the deposition method. Scanning electron microscopy images showed the presence of agglomerates with diameters in the submicrometre scale composed of nano-sized particles. The catalysts prepared by multiple cycles of potentiostatic pulses exhibited better activity for methanol oxidation and enhanced tolerance to CO poisoning compared with those prepared by the other techniques. This behaviour could be associated with the structure containing a high number of defects of the particles and a higher ruthenium content in the solid solution.
Symbiotic skin bacteria as a source for sex-specific scents in frogs
Authors: Brunetti Andrés E. , Lyra Mariana L. , Melo Weilan G. P. , Andrade Laura E. , Palacios-Rodríguez Pablo , Prado Bárbara M. , Haddad Célio F. B. , Pupo Mônica T. , Lopes Norberto P.
Published: January 2019

Amphibians are known to possess a wide variety of compounds stored in their skin glands. While significant progress has been made in understanding the chemical diversity and biological relevance of alkaloids, amines, steroids, and peptides, most aspects of the odorous secretions are completely unknown. In this study, we examined sexual variations in the volatile profile from the skin of the tree frogBoana prasinaand combined culture and culture-independent methods to investigate if microorganisms might be a source of these compounds. We found that sesquiterpenes, thioethers, and methoxypyrazines are major contributors to the observed sex differences. We also observed that each sex has a distinct profile of methoxypyrazines, and that the chemical origin of these compounds can be traced to aPseudomonassp. strain isolated from the frog’s skin. This symbiotic bacterium was present in almost all individuals examined from different sites and was maintained in captive conditions, supporting its significance as the source of methoxypyrazines in these frogs. Our results highlight the potential relevance of bacteria as a source of chemical signals in amphibians and contribute to increasing our understanding of the role that symbiotic associations have in animals.
Triparental inheritance in
Dictyostelium
Authors: Bloomfield Gareth , Paschke Peggy , Okamoto Marina , Stevens Tim J. , Urushihara Hideko
Published: January 2019

Sex promotes the recombination and reassortment of genetic material and is prevalent across eukaryotes, although our knowledge of the molecular details of sexual inheritance is scant in several major lineages. In social amoebae, sex involves a promiscuous mixing of cytoplasm before zygotes consume the majority of cells, but for technical reasons, sexual progeny have been difficult to obtain and study. We report here genome-wide characterization of meiotic progeny in
Dictyostelium discoideum
. We find that recombination occurs at high frequency in pairwise crosses between all three mating types, despite the absence of the Spo11 enzyme that is normally required to initiate crossover formation. Fusions of more than two gametes to form transient syncytia lead to frequent triparental inheritance, with haploid meiotic progeny bearing recombined nuclear haplotypes from two parents and the mitochondrial genome from a third. Cells that do not contribute genetically to the
Dictyostelium
zygote nucleus thereby have a stake in the next haploid generation.
D. discoideum
mitochondrial genomes are polymorphic, and our findings raise the possibility that some of this variation might be a result of sexual selection on genes that can promote the spread of individual organelle genomes during sex. This kind of self-interested mitochondrial behavior may have had important consequences during eukaryogenesis and the initial evolution of sex.
Enhancing human learning via spaced repetition optimization
Authors: Tabibian Behzad , Upadhyay Utkarsh , De Abir , Zarezade Ali , Schölkopf Bernhard , Gomez-Rodriguez Manuel
Published: January 2019

Spaced repetition is a technique for efficient memorization which uses repeated review of content following a schedule determined by a spaced repetition algorithm to improve long-term retention. However, current spaced repetition algorithms are simple rule-based heuristics with a few hard-coded parameters. Here, we introduce a flexible representation of spaced repetition using the framework of marked temporal point processes and then address the design of spaced repetition algorithms with provable guarantees as an optimal control problem for stochastic differential equations with jumps. For two well-known human memory models, we show that, if the learner aims to maximize recall probability of the content to be learned subject to a cost on the reviewing frequency, the optimal reviewing schedule is given by the recall probability itself. As a result, we can then develop a simple, scalable online spaced repetition algorithm, MEMORIZE, to determine the optimal reviewing times. We perform a large-scale natural experiment using data from Duolingo, a popular language-learning online platform, and show that learners who follow a reviewing schedule determined by our algorithm memorize more effectively than learners who follow alternative schedules determined by several heuristics.
Translation memories and the translator
Authors: Schneider Dominik , Zampieri Marcos , van Genabith Josef
Published: January 2019

This paper presents a comprehensive study on the use of translation memory software by translators of different backgrounds. We designed a questionnaire that was completed by a pool of 723 respondents including professional translators, translation students, and lecturers in translation studies and translation practice. We analyse the results of the survey providing important information concerning user requirements, the most important features of TM software, users’ perceived productivity, and market shares.
Coenzyme Q biosynthetic proteins assemble in a substrate-dependent manner into domains at ER–mitochondria contacts
Authors: Subramanian Kelly , Jochem Adam , Le Vasseur Maxence , Lewis Samantha , Paulson Brett R. , Reddy Thiruchelvi R. , Russell Jason D. , Coon Joshua J. , Pagliarini David J. , Nunnari Jodi
Published: January 2019

Coenzyme Q (CoQ) lipids are ancient electron carriers that, in eukaryotes, function in the mitochondrial respiratory chain. In mitochondria, CoQ lipids are built by an inner membrane–associated, multicomponent, biosynthetic pathway via successive steps of isoprenyl tail polymerization, 4-hydroxybenzoate head-to-tail attachment, and head modification, resulting in the production of CoQ. In yeast, we discovered that head-modifying CoQ pathway components selectively colocalize to multiple resolvable domains in vivo, representing supramolecular assemblies. In cells engineered with conditional ON or OFF CoQ pathways, domains were strictly correlated with CoQ production and substrate flux, respectively, indicating that CoQ lipid intermediates are required for domain formation. Mitochondrial CoQ domains were also observed in human cells, underscoring their conserved functional importance. CoQ domains within cells were highly enriched adjacent to ER–mitochondria contact sites. Together, our data suggest that CoQ domains function to facilitate substrate accessibility for processive and efficient CoQ production and distribution in cells.
Mentors: Ron Kaback
Authors: Carrasco Nancy
Published: January 2019

Carrasco reflects on her postdoctoral advisor, Ron Kaback—an exceptional scientist and inspiring mentor.
Galactic halo age estimated from LAMOST DR4 and Gaia DR1
Authors: Guo Jin-Cheng , Zhang Hua-Wei , Huang Yang , Liu Xiao-Wei , Liu Ji-Feng , Xiang Mao-Sheng , Chen Bing-Qiu , Yuan Hai-Bo , Tian Zhi-Jia , Huo Zhi-Ying , Wang Chun
Published: January 2019

The stellar halo is one of the major components in the Milky Way. Research on its age can provide critical constraints on the origin of the stellar halo and further on the formation of our Galaxy. So far, different approaches and samples have been used to estimate the age of the Galactic halo. In our previous paper, we carefully selected 63 field halo turn-off stars within 1 kpc from the literature using a kinematic approach, then estimated the age of the halo. In this following work, we not only update the data from LAMOST DR4 and Gaia DR1, but also try a different method to select a clean halo sample by combining the metallicity and orbital parameters. Then we compare this halo turn-off sample with the GARSTEC model in the B – V vs. metallicity plane. After Monte Carlo simulations are performed, the age is estimated to be 10.5±1.4 Gyr, highly consistent with our previous result and other studies. However, due to the limited common sources between LAMOST DR4 and Gaia DR1, the final sample in this paper is still quite small. The estimated age will be more robust with the much larger Gaia DR2.