bluuebunny/crossref_metadata_2025 huggingface dataset:
Fuzzy logic controller for stabilization of biped robot gait
Authors: Ryadchikov I.V. , Sechenev S.I. , Gusev A.A.
Published: April 2018

The article centers round the problem of stabilization of biped robot gait through smoothing out the jumps of first and second order derivatives of a biped robot control vector using the fuzzy logic approach. The structure of a composite Takagi-Sugeno fuzzy logic controller developed by the authors is presented. The simulation study of a robot gait with climbing an obstacle is carried out and the results provided in the article showed that the developed controller performed significantly better than the analytical formula model in terms of smoothing out the derivatives of the control vector.
Economic optimization and evolutionary programming when using remote sensing data
Authors: Shamin Roman , Alberto Gabriel Enrike , Uryngaliyeva Ayzhana , Semenov Aleksandr
Published: April 2018

The article considers the issues of optimizing the use of remote sensing data. Built a mathematical model to describe the economic effect of the use of remote sensing data. It is shown that this model is incorrect optimisation task. Given a numerical method of solving this problem. Also discusses how to optimize organizational structure by using genetic algorithm based on remote sensing. The methods considered allow the use of remote sensing data in an optimal way. The proposed mathematical model allows various generalizations for optimization of decision making in the presence of remote sensing data. The approach associated with evolutionary programming is an effective solution when optimizing economic structures in the presence of remote sensing data.
Does symbolic and non-symbolic estimation ability predict mathematical achievement across primary school years?
Authors: Tikhomirova Tatiana , Kuzmina Yulia , Malykh Sergey
Published: April 2018

The article presents the results of a longitudinal study of the association between number sense and success in learning mathematics in primary school. We analysed the data of 133 schoolchildren on two aspects of number sense related to the symbolic and non-symbolic magnitude estimation abilities and academic success in mathematics in third and fourth grade. The average age of schoolchildren during the first assessment was 9.82 ± 0.30; during the second assessment – 10.82 ± 0.30. For the analysis of interrelations, the cross-lagged method was used. It was shown that the reciprocal model best describes the data suggesting cross-lagged associations between number sense and the success in learning mathematics at primary school age. The results of the longitudinal analysis revealed differences in the relationship between the success in learning mathematics with the two aspects of number sense: academic success in third grade only predicted the indicator of number sense associated with the symbolic magnitude estimation ability in fourth grade. The differences in the age dynamics of the two aspects of number sense in primary school are also revealed: the indicator of number sense associated with the non-symbolic magnitude estimation ability was the most stable over time.
Direct Torque Control with Adaptive PI Speed Controller based on Neural Network for PMSM Drives
Authors: Zhenyu Jia, , Byeongwoo Kim,
Published: April 2018

This paper presents an adaptive speed controller based on artificial intelligent technique to improvethe performance of classical Direct Torque Control (DTC) for Permanent Magnet Synchronous Motor (PMSM) drives. The proposed method applies back propagation (BP) based neural network (NN) to tune the parameters of classical proportional-integral (PI) speed controller. Comparisons between conventional PI speed controller and proposed method are carried out by Simulation.Simulation results demonstrate that conventional DTC system based on the proposed NN speed controller can achieve higher performance with fast speed response, small overshoot and robustness.
The Strategy of Inverter Seamless Mode Switching in Master-Slave Independent Micro-grid
Authors: Jiang Hanhong , Lu Yao , Wu You , Wang Yi
Published: April 2018

In order to realize the uninterruptible power supply in the master-slave independent micro-grid system, the micro-grid inverter needs to realize the mode switching of the grid-connection/grid-disconnection. How to reduce the transient oscillation during switching, so as to effectively achieve seamless mode switching is a key issue to be solved. In this paper, a typical master-slave control independent micro-grid is used as an example, the strategy of mode switching is improved in two aspects. On the one hand, the state-following algorithm is adopted to improve the switching strategy of the outer loop. On the other hand, the current inner loop is taken by the H∞ robust controller to improve the robustness of the controller. Compared with the traditional PI control mode switching, this paper illustrates the feasibility of the proposed strategy through the simulation and experiment verification. The improvement strategy in this paper can effectively reduce the voltage and current oscillation during mode switching.
Nanocrystalization of Pioglitazone by Precipitation Method
Authors: Varshosaz Jaleh , Ahmadipour Saeedeh , Tabbakhian Majid , Ahmadipour Shokoufeh
Published: April 2018

Background Poor solubility in aqueous medium limits the use of many drugs. Different methods have been adopted to promote the rate of dissolution of slightly water soluble drugs. Crystallization improves solubility, and bioavailability by increasing the surface area of slightly water soluble drugs. Pioglitazone (PGZ), which is a class II Biopharmaceutical Classification System drug has a slight solubility in water and a slow rate of dissolution, which may have a negative effect on its metabolism leading to a therapeutic failure.

Aim The aim of this study was to improve the solubility of PGZ-HCl; an antidiabetic drug using precipitation method.

Materials and Methods Formulations were prepared with polyethylene glycol 6000 and isomalt using different speed of homogenizer and quantity of solvent by precipitation method. Drug-polymer interactions were examined using differential scanning calorimetry (DSC), and Powder X-Ray Diffraction (PXRD). Surface structure were shown by SEM photographs.

Results The particle size was significantly decreased and solubility was enhanced with increase speed, ethanol solvent and increase stabilizer, however very high amount of stabilizer resulted in a decrease in solubility.

Conclusion This result however showed that solid dispersion technique is a potential method for increasing dissolution profile of a poorly aqueous soluble agent.
Vorhersage von modalitätsspezifischen Arbeitsgedächtnisleistungen im Kindergartenalter
Authors: Kiese-Himmel Christiane
Published: April 2018

Hintergrund Das Arbeitsgedächtnis (AG) als ein zentrales kognitives Konstrukt ist eine fundamentale Voraussetzung für Lernen und gilt als Marker für
Entwicklungsstörungen. In den letzten Jahren hat es beachtliche Aufmerksamkeit in der Forschung gewonnen. Um Prädiktoren für phonologische und visuelle
AG-Leistungen zu bestimmen, wurden hier multivariate Regressionsanalysen mittels generalisierter linearer Modelle gerechnet.

Material und Methoden Das phonologische AG wurde durch das Nachsprechen von Nichtwörtern (SETK 3–5-Subtest PGN) und von Zahlenfolgen (K-ABC-Subtest), das
visuell-räumliche durch die Imitation von Handbewegungen (K-ABC-Subtest) untersucht. Eine Intelligenzschätzung wurde durch das Ergebnis in der K-ABC-Skala
„Ganzheitliches Denken“ vorgenommen. Stichprobe: 169 Kindergartenkinder (49 % Jungen; 51 % Mädchen), überwiegend mit Migrationshintergrund und Deutsch als
Zweitsprache, im mittleren Alter von 45,9 (SD 6,2; Min 36; Max 61) Monaten; zum Zeitpunkt der Untersuchung im Durchschnitt seit 9,9 (SD 6,9) Monaten im
Kindergarten und durchschnittlich intelligent. Als Faktoren wurden Geschlecht und Migrationshintergrund festgelegt, als Kovariaten Lebensalter, Dauer des
Kindergartenbesuchs bis zur Testung sowie ganzheitliches Denken in die Modelle aufgenommen.

Ergebnisse Alle mittleren AG-Leistungen waren durchschnittlich. Nur das Alter zum Untersuchungszeitpunkt sowie das ganzheitliche Denken hatte einen
signifikanten Einfluss auf die AG-Leistungen.

Schlussfolgerung Im Alter von 36–61 Monaten lassen sich die beiden o. g. Arbeitsgedächtnissysteme als ein anlagebedingter, reifungsabhängiger und eher
geschlechtsunspezifischer Mechanismus beschreiben.
Interne Validität des Acoustic Voice Quality Index Version
03.01 und des Acoustic Breathiness Index
Authors: Latoszek Ben Barsties v. , Lehnert Bernhard
Published: April 2018

Hintergrund Akustische Messverfahren haben das Potential Heiserkeit und
Behauchtheit objektiv zu messen und der Acoustic Voice Quality Index (AVQI) und
der Acoustic Breathiness Index (ABI) zeigen gute Ergebnisse hinsichtlich
Validität und Reliabilität. Das Ziel dieser Studie war die Überprüfung der
internen Validität der aktuellen Version des AVQI 03.01 und des ABI im
Deutschen. Hierzu wurde die Sensitivität gegenüber Stimmveränderungen im
Heiserkeits- und Behauchtheitsgrad durch logopädische Stimmtherapie
untersucht.

Material und Methoden Insgesamt wurden 84 Stimmaufzeichnungen von
fortlaufender Sprache und dem Vokal [a:] vor und nach einer Stimmtherapie
verwendet. Alle Aufnahmen der 42 Probanden stammten von Stimmpatienten mit
unterschiedlichen Schweregraden einer Dysphonie vor und nach einer konservativen
Therapie. Alle Stimmen wurden von drei Stimmexperten nach dem RBH-System
beurteilt.

Ergebnisse Die Intra- Beurteiler Reliabilität ergab insgesamt eine hohe
Reliabilität für Heiserkeit (Kappa Mittelwert = 0,76) und Behauchtheit (Kappa
Mittelwert = 0,69). Die Inter- Beurteiler Reliabilität erreichte hingegen eine
niedrigere Reliabilität für beide Stimmqualitätsaspekte, die zwischen Kappa =
0,27 und 0,29 lag. Für beide Messverfahren, AVQI und ABI, zeigte sich ein
deutlicher Zusammenhang zwischen der Perzeption von Veränderungen der
Stimmqualität vor und nach der Therapie und dem Messergebnis (Heiserkeit vs.
AVQI: r = 0,715, p < 0,01 und Behauchtheit vs. ABI: r = 0,712, p < 0,01).
Die Unterschiede waren auch nicht signifikant.

Schlussfolgerung Die Resultate zeigten, dass AVQI Version 03.01 und ABI
eine hohe interne Validität haben, um Stimmveränderungen nach Intervention zu
erfassen. AVQI und ABI sind zwei valide und robuste Messinstrumente, die
Heiserkeit und Behauchtheit objektiv messen können.
Upper Blepharoplasty: Management of the Upper Eyelid and Brow Complex via Transblepharoplasty Approach
Authors: Pham Tuan
Published: April 2018

Upper blepharoplasty is one of the more common facial plastic procedures. The upper lid and brow complex are managed together. Whether upper blepharoplasty is performed for medical or cosmetic reasons, the aim is to improve appearance while retaining natural shape and maintaining (or improving) function. For optimal results, it is important to understand relevant eyelid anatomy and the concept of maintaining youthful volume and position of the eyelid brow orbit complex. Management of patient expectations, meticulous planning, and a degree of surgical finesse all contribute to the desired outcome. The article will focus on the assessment, techniques, and complications of upper blepharoplasty, which involve management of the skin, orbicularis oculi, preaponeurotic fat, levator aponeurosis and muscle as related to concomitant ptosis, and lateral brow complex via transblepharoplasty (internal) brow lift and fixation.
Aesthetics and Rejuvenation of the Temple
Authors: Rihani Jordan
Published: April 2018

The temples are an often overlooked, but important element of facial rejuvenation. The anatomy of the temple should be understood prior to any intervention in this location. Multimodal treatment to re-establish youthful convexity, proper hairline position, and correct actinic damage is recommended for optimal results. Important anatomy, aesthetic goals, and methods of rejuvenation are reviewed in detail.
Fat Grafting Volume Restoration to the Brow and Temporal Regions
Authors: Tzikas Thomas
Published: April 2018

Primary manifestations of facial aging are the reduction in subcutaneous tissue volume, especially the atrophy of fat as well as bone volume depletion which directly contribute to loss of support and laxity of the skin. Depressions and hollows develop with a visible disruption of the cosmetic facial aesthetic units resulting in harsh shadows. This is especially evident in the eyebrow and temporal regions which accentuate the appearance of brow ptosis and a hollow, almost cadaveric look to the temple. Restoration of volume to these areas has been shown to rejuvenate the upper face creating a softer, fuller, and more youthful appearance. Fat grafting by itself or in combination with upper facial surgical procedures plays a major role in the restoration of youthful facial qualities in this region.
Acute Hypoxia Induces Enkephalin Production and Release in an Adrenergic Cell Line Model of Neonatal Chromaffin Cell Responses to Hypoxic Stress
Authors: Calero Alexa , Villanueva Hazel , Giri Priyadarshani , Tischler Arthur , Powers James , Evinger Marian
Published: April 2018

Objective Prior to maturation of the human sympathetic nervous system, the neonatal adrenal medulla senses and responds to hypoxia. In addition to catecholamine release, the adrenal medulla synthesizes and stores opioid peptides, notably enkephalin (ENK). However, it is not known whether acute hypoxia evokes adrenal ENK production and release, as seen in the central nervous system (CNS). We hypothesize that acute hypoxia stimulates synthesis and release of ENK in chromaffin cells.

Study Design Cultures of adrenergic mouse pheochromocytoma cells (MPC) 10/9/96CR were incubated in 10% oxygen (O2) at intervals of up to 60 minutes. ENK content and release were measured by Met-ENK enzyme-linked immunosorbent assay (ELISA). ENK messenger ribonucleic acid (mRNA) was analyzed by quantitative reverse-transcriptase polymerase chain reaction (PCR).

Results Incubation of MPC 10/9 cells in 10% O2 evoked rapid release of epinephrine and of Met-ENK which increased approximately twofold in 15 minutes. Reduced [O2] also induced an overall increase (14%) in cellular ENK peptide content within 60 minutes. Acute hypoxia-stimulated release of Met-ENK was accompanied by increased mRNAENK expression in MPC 10/9s, a cell culture model of adrenergic chromaffin cells.

Conclusion We speculate that the ability of reduced [O2] to evoke ENK release from chromaffin cells may influence blood pressure regulation and heart contractility, thereby providing an adaptive survival advantage during neonatal asphyxia.
Spectral semi-classical analysis of a complex Schrödinger operator in exterior domains
Authors: Almog Y. , Grebenkov D. S. , Helffer B.
Published: April 2018

Generalizing previous results obtained for the spectrum of the Dirichlet and Neumann realizations in a bounded domain of a Schrödinger operator with a purely imaginary potential −h2Δ + iV in the semiclassical limit h → 0, we address the same problem in exterior domains. In particular, we obtain the left margin of the spectrum and the emptiness of the essential part of the spectrum under some additional assumptions.
Using reweighting and free energy surface interpolation to predict solid-solid phase diagrams
Authors: Schieber Natalie P. , Dybeck Eric C. , Shirts Michael R.
Published: April 2018

Many physical properties of small organic molecules are dependent on the current crystal packing, or polymorph, of the material, including bioavailability of pharmaceuticals, optical properties of dyes, and charge transport properties of semiconductors. Predicting the most stable crystalline form at a given temperature and pressure requires determining the crystalline form with the lowest relative Gibbs free energy. Effective computational prediction of the most stable polymorph could save significant time and effort in the design of novel molecular crystalline solids or predict their behavior under new conditions. In this study, we introduce a new approach using multistate reweighting to address the problem of determining solid-solid phase diagrams and apply this approach to the phase diagram of solid benzene. For this approach, we perform sampling at a selection of temperature and pressure states in the region of interest. We use multistate reweighting methods to determine the reduced free energy differences between T and P states within a given polymorph and validate this phase diagram using several measures. The relative stability of the polymorphs at the sampled states can be successively interpolated from these points to create the phase diagram by combining these reduced free energy differences with a reference Gibbs free energy difference between polymorphs. The method also allows for straightforward estimation of uncertainties in the phase boundary. We also find that when properly implemented, multistate reweighting for phase diagram determination scales better with the size of the system than previously estimated.
Note: Comparison experimental results of the laser heterodyne interferometer for angle measurement based on the Faraday effect
Authors: Zhang Enzheng , Chen Benyong , Zheng Hao , Teng Xueying , Yan Liping
Published: April 2018

A laser heterodyne interferometer for angle measurement based on the Faraday effect is proposed. A novel optical configuration, designed by using the orthogonal return method for a linearly polarized beam based on the Faraday effect, guarantees that the measurement beam can return effectively even though an angular reflector has a large lateral displacement movement. The optical configuration and measurement principle are presented in detail. Two verification experiments were performed; the experimental results show that the proposed interferometer can achieve a large lateral displacement tolerance of 7.4 mm and also can realize high precision angle measurement with a large measurement range.
Low-lying excited states by constrained DFT
Authors: Ramos Pablo , Pavanello Michele
Published: April 2018

Exploiting the machinery of Constrained Density Functional Theory (CDFT), we propose a variational method for calculating low-lying excited states of molecular systems. We dub this method eXcited CDFT (XCDFT). Excited states are obtained by self-consistently constraining a user-defined population of electrons, Nc, in the virtual space of a reference set of occupied orbitals. By imposing this population to be Nc = 1.0, we computed the first excited state of 15 molecules from a test set. Our results show that XCDFT achieves an accuracy in the predicted excitation energy only slightly worse than linear-response time-dependent DFT (TDDFT), but without incurring into problems of variational collapse typical of the more commonly adopted ΔSCF method. In addition, we selected a few challenging processes to test the limits of applicability of XCDFT. We find that in contrast to TDDFT, XCDFT is capable of reproducing energy surfaces featuring conical intersections (azobenzene and H3) with correct topology and correct overall energetics also away from the intersection. Venturing to condensed-phase systems, XCDFT reproduces the TDDFT solvatochromic shift of benzaldehyde when it is embedded by a cluster of water molecules. Thus, we find XCDFT to be a competitive method among single-reference methods for computations of excited states in terms of time to solution, rate of convergence, and accuracy of the result.
Instability and thermal conductivity of pressure-densified and elastically altered orientational glass of Buckminsterfullerene
Authors: Johari G. P. , Andersson Ove , Sundqvist Bertil
Published: April 2018

We report on the temperature, pressure, and time (T, p, and t)-dependent features of thermal conductivity, κ, of partially ordered, non-equilibrium state of C60-OG, the orientational glass of Buckminsterfullerene (at T below the orientational freezing temperature Tog) made more unstable (i) by partially depressurizing its high-p formed state to elastically expand it and (ii) by further pressurizing that state to elastically contract it. The sub-Tog effects observed on heating of C60-OG differ from those of glasses because phonon propagation depends on the ratio of two well-defined orientational states of C60 molecules and the density of the solid. A broad peak-like feature appears at T near Tog in the κ-T plots of C60-OG formed at 0.7 GPa, depressurized to 0.2 GPa and heated at 0.2 GPa, which we attribute to partial overlap of the sub-Tog and Tog features. A sub-Tog local minimum appears in the κ-T plots at T well below Tog of C60-OG formed at 0.1 GPa, pressurized to 0.5 GPa and heated at 0.5 GPa and it corresponds to the state of maximum disorder. Although Buckminsterfullerene is regarded as an orientationally disordered crystal, variation of its properties with T and p is qualitatively different from other such crystals. We discuss the findings in terms of the nature of its disorder, sensitivity of its rotational dynamics to temperature, and the absence of the Johari-Goldstein relaxation. All seem to affect the phenomenology of its glass-like transition.
Quantum size effect in an Fe quantum well detected by resonant tunneling carriers injected from a p-type Ge semiconductor electrode
Authors: Suzuki Ryota , Wakabayashi Yuki K. , Okamoto Kohei , Tanaka Masaaki , Ohya Shinobu
Published: April 2018

We report the clear observation of the quantum size effect in an Fe quantum well (QW) detected by resonant tunneling carriers injected from a p-type Ge semiconductor electrode in fully epitaxial double-barrier magnetic tunnel junctions, which are composed of Co/Fe/MgO/Fe QW/MgO/Ge:B grown on a p+-Ge(001) substrate. A large tunnel magnetoresistance (TMR) ratio up to 137% (237%), which is comparable to that in Fe/MgO/Fe, is obtained at 297 K (3.5 K). The quantum oscillations are clearly observed in the dI/dV–V and d2I/dV2–V curves of our devices, and the resonance voltages are in good agreement with the resonant levels calculated by the phase accumulation model. Following these oscillations, the TMR is modulated by the quantum size effect. Our results are promising for realizing future quantum spintronics devices based on semiconductor/metal hybrid heterostructures with advanced functionalities.
Dropwise condensation on hydrophobic bumps and dimples
Authors: Yao Yuehan , Aizenberg Joanna , Park Kyoo-Chul
Published: April 2018

Surface topography plays an important role in promoting or suppressing localized condensation. In this work, we study the growth of water droplets on hydrophobic convex surface textures such as bumps and concave surface textures such as dimples with a millimeter scale radius of curvature. We analyze the spatio-temporal droplet size distribution under a supersaturation condition created by keeping the uniform surface temperature below the dew point and show its relationship with the sign and magnitude of the surface curvature. In particular, in contrast to the well-known capillary condensation effect, we report an unexpectedly less favorable condensation on smaller, millimeter-scale dimples where the capillary condensation effect is negligible. To explain these experimental results, we numerically calculated the diffusion flux of water vapor around the surface textures, showing that its magnitude is higher on bumps and lower on dimples compared to a flat surface. We envision that our understanding of millimetric surface topography can be applied to improve the energy efficiency of condensation in applications such as water harvesting, heating, ventilation, and air conditioning systems for buildings and transportation, heat exchangers, thermal desalination plants, and fuel processing systems.
Atmospheric pressure reaction cell for operando sum frequency generation spectroscopy of ultrahigh vacuum grown model catalysts
Authors: Roiaz Matteo , Pramhaas Verena , Li Xia , Rameshan Christoph , Rupprechter Günther
Published: April 2018

A new custom-designed ultrahigh vacuum (UHV) chamber coupled to a UHV and atmospheric-pressure-compatible spectroscopic and catalytic reaction cell is described, which allows us to perform IR-vis sum frequency generation (SFG) vibrational spectroscopy during catalytic (kinetic) measurements. SFG spectroscopy is an exceptional tool to study vibrational properties of surface adsorbates under operando conditions, close to those of technical catalysis. This versatile setup allows performing surface science, SFG spectroscopy, catalysis, and electrochemical investigations on model systems, including single crystals, thin films, and deposited metal nanoparticles, under well-controlled conditions of gas composition, pressure, temperature, and potential. The UHV chamber enables us to prepare the model catalysts and to analyze their surface structure and composition by low energy electron diffraction and Auger electron spectroscopy, respectively. Thereafter, a sample transfer mechanism moves samples under UHV to the spectroscopic cell, avoiding air exposure. In the catalytic cell, SFG spectroscopy and catalytic tests (reactant/product analysis by mass spectrometry or gas chromatography) are performed simultaneously. A dedicated sample manipulation stage allows the model catalysts to be examined from LN2 temperature to 1273 K, with gaseous reactants in a pressure range from UHV to atmospheric. For post-reaction analysis, the SFG cell is rapidly evacuated and samples are transferred back to the UHV chamber. The capabilities of this new setup are demonstrated by benchmark results of CO adsorption on Pt and Pd(111) single crystal surfaces and of CO adsorption and oxidation on a ZrO2 supported Pt nanoparticle model catalyst grown by atomic layer deposition.
Microsolvation of phthalocyanine molecules in superfluid helium nanodroplets as revealed by the optical line shape at electronic origin
Authors: Fuchs S. , Fischer J. , Slenczka A. , Karra M. , Friedrich B.
Published: April 2018

We investigate the solvent shift of phthalocyanine (Pc) doped into superfluid helium droplets and probed by optical spectroscopy at the electronic origin. Our present work complements extant studies and provides results that in part contradict previous conclusions. In particular, the solvent shift does not increase monotonously with droplet radius all the way up to the bulk limit, but exhibits just the reverse dependence instead. Moreover, a substructure is resolved, whose characteristics depend on the droplet size. This behavior can hardly be reconciled with that of a freely rotating Pc-helium complex.
Nanostructuring of conduction channels in (In,Ga)As-InP heterostructures: Overcoming carrier generation caused by Ar ion milling
Authors: Hortelano V. , Weidlich H. , Semtsiv M. P. , Masselink W. T. , Ramsteiner M. , Jahn U. , Biermann K. , Takagaki Y.
Published: April 2018

Nanometer-sized channels are fabricated in (In,Ga)As-InP heterostructures using Ar ion milling. The ion milling causes spontaneous creation of nanowires, and moreover, electrical conduction of the surface as carriers is generated by sputtering-induced defects. We demonstrate a method to restore electrical isolation in the etched area that is compatible with the presence of the nanochannels. We remove the heavily damaged surface layer using a diluted HCl solution and subsequently recover the crystalline order in the moderately damaged part by annealing. We optimize the HCl concentration to make the removal stop on its own before reaching the conduction channel part. The lateral depletion in the channels is shown to be almost absent.
Spectroscopic method to study low charge state ion and cold electron population in ECRIS plasma
Authors: Kronholm R. , Kalvas T. , Koivisto H. , Tarvainen O.
Published: April 2018

The results of optical emission spectroscopy experiments probing the cold electron population of a 14 GHz Electron Cyclotron Resonance Ion Source (ECRIS) are reported. The study has been conducted with a high resolution spectrometer and data acquisition setup developed specifically for the diagnostics of weak emission line characteristic to ECRIS plasmas. The optical emission lines of low charge state ions and neutral atoms of neon have been measured and analyzed with the line-ratio method. The aforementioned electron population temperature of the cold electron population (Te < 100 eV) is determined for Maxwell-Boltzmann and Druyvesteyn energy distributions to demonstrate the applicability of the method. The temperature was found to change significantly when the extraction voltage of the ion source is turned on/off. In the case of the Maxwellian distribution, the temperature of the cold electron population is 20 ± 10 eV when the extraction voltage is off and 40 ± 10 eV when it is on. The optical emission measurements revealed that the extraction voltage also affects both neutral and ion densities. Based on the rate coefficient analysis with the aforementioned temperatures, switching the extraction voltage off decreases the rate coefficient of neutral to 1+ ionization to 42% and 1+ to 2+ ionization to 24% of the original. This suggests that switching the extraction voltage on favors ionization to charge states ≥2+ and, thus, the charge state distributions of ECRIS plasmas are probably different with the extraction voltage on/off. It is therefore concluded that diagnostics results of ECRIS plasmas obtained without the extraction voltage are not depicting the plasma conditions in normal ECRIS operation.
Polymer effects on Kármán vortex: Molecular dynamics study
Authors: Asano Yuta , Watanabe Hiroshi , Noguchi Hiroshi
Published: April 2018

We investigated the Kármán vortex behind a circular cylinder in a polymer solution by a molecular dynamics simulation. The vortex characteristics are distinctly different for short and long polymers. The solution with the long polymer exhibits a reduction in the vortex shedding frequency and broadening of the lift coefficient spectrum. On the other hand, the characteristics of the short-polymer solution are almost the same as those of the Newtonian fluid. These facts are consistent with the experiments. Because the distributions of the gyration radius and the orientational order of the long-polymer solution are highly inhomogeneous in the flow field, we conclude that the extensional property of the polymer plays an important role in changing the flow characteristics.
The dependency of adhesion and friction on electrostatic attraction
Authors: Persson B. N. J.
Published: April 2018

I develop a general mean-field theory for the influence of electrostatic attraction between two solids on the contact mechanics. I assume elastic solids with random surface roughness. I consider two cases, namely, with and without an electrically insulating layer between the conducting solids. The former case is important for, e.g., the finger–touch screen interaction. I study how the electrostatic attraction influences the adhesion and friction. For the case of an insulating layer, I find that when the applied nominal contact pressure is relatively small, as the applied voltage increases, there is a sharp increase in the contact area, and hence in the friction, at a critical voltage.
On the origin of the low-temperature band in depolarization current spectra of poled multicomponent silicate glasses
Authors: Brunkov P. N. , Kaasik V. P. , Lipovskii A. A. , Tagantsev D. K.
Published: April 2018

Thermally stimulated depolarization current spectra of poled silicate multicomponent glasses in the vicinity of room temperature (220–320 K) have been recorded and two bands, typical for such glasses, have been observed. It was shown that the high-temperature band (at about 290 K) is related to the relaxation of poled glass structure in the bulk, while the low-temperature band (at about 230–270 K) should be attributed to the surface phenomenon—absorption/desorption of positive species of ambient atmosphere, supposedly, water cluster ions H+(H2O)n.
Local structure of Ge2Sb2Te5 during crystallization under pressure
Authors: Roscioni O. M. , Branicio P. S. , Kalikka J. , Zhou X. , Simpson R. E.
Published: April 2018

The role of stress on the crystallization process of the phase change data storage material, Ge2Sb2Te5, is studied. When thin Ge2Sb2Te5 films are capped with Si3N4, stress is generated in the Ge2Sb2Te5 layer which causes the crystallization temperature to increase. Si3N4 films of 25 nm thickness increase the crystallization temperature from 446 K to 464 K. We show that stress predominantly destabilizes voids and increases the number of Ge-Sb and homopolar bonds in the vicinity of Ge atoms, and this makes the crystallization less probable, thus resulting in the increase in the measured temperature.
NMR and DFT Studies of 2-Oxo-1,2,3,4-tetrahydropyridines: Solvent and Temperature Effects
Authors: Memarian Hamid R. , Kalantari Mahdieh , Sabzyan Hassan
Published: April 2018

Various 5-carboethoxy-2-oxo-1,2,3,4-tetrahydropyridines and their corresponding oxidation products containing methoxy or nitro groups on different positions of the C4-aryl ring were synthesized and the effect of steric and electrostatic interactions of these aryl substituents on the characteristic peaks in 1H NMR spectra were investigated. In addition, the intermolecular interaction of the parent compound and its oxidized form with solvent was experimentally investigated. For this, 1H NMR spectra of these compounds at different concentrations and temperatures in [D6]DMSO and CDCl3 were investigated. For comparison of the dimerization ability of these heterocyclic compounds with different conformations, the binding electronic energies, the total enthalpies and free energies of dimerization in the gas and solution phases, and the QTAIM (quantum theory of atoms-in-molecules) analysis were determined. These interactions were also studied using density functional theory at the B3LYP/6–311++G(d,p) level. The theoretical results are in good agreement with the experimental results and indicate that the electronic effect of the methoxy and nitro groups on the C4-aryl ring influences the electron density of the heterocyclic ring via the σ bond and, consequently, the chemical shift of the heterocyclic ring protons.
CASA in invertebrates
Authors: van der Horst Gerhard , Bennett Monique , Bishop John D. D.
Published: April 2018

Sperm movement has been described in several phyla of invertebrates. Yet, sperm motility has only been quantified using computer-aided sperm analysis (CASA-Mot) in externally fertilising species (broadcast spawners) of two phyla, molluscs and echinoderms. In the present study we quantified in detail the nature of the sperm tracks, percentage motility groupings and detailed kinematics of rapid-, medium- and slow-swimming spermatozoa in the oyster Crassostrea gigas and four species never previously studied by CASA-Mot, namely the molluscs Choromytilus meridionalis, Donax serra and Haliotis midae and the echinoderm Parechinus angulosus. A feature common to all these species are the helical tracks, the diameter of which seems to be species specific. Using CASA-Mot, the behaviour of spermatozoa was also studied over time and in the presence of egg water and Ca2+ modulators such as caffeine and procaine hydrochloride. For the first time, we show that hyperactivation can be induced in all species in the presence of egg water (sea water that was mixed with mature eggs and then centrifuged) and/or caffeine, and these hyperactivated sperm tracks were characterised using CASA-Mot. We relate the different patterns of sperm motility and behaviour to reproductive strategies such as broadcast spawning and spermcasting, and briefly review studies using CASA-Mot on other invertebrates.
Ecological responses of Stipa steppe in Inner Mongolia to experimentally increased temperature and precipitation. 4. Carbon exchange
Authors: Chao Luomeng , Wan Zhiqiang , Yan Yulong , Gu Rui , Chen Yali , Gao Qingzhu
Published: April 2018

Aspects of carbon exchange were investigated in typical steppe east of Xilinhot city in Inner Mongolia. Four treatments with four replicates were imposed in a randomised block design: Control (C), warming (T), increased precipitation (P) and combined warming and increased precipitation (TP). Increased precipitation significantly increased both ecosystem respiration (ER) and soil respiration (SR) rates. Warming significantly reduced the ER rate but not the SR rate. The combination of increased precipitation and warming produced an intermediate response. The sensitivity of ER and SR to soil temperature and air temperature was assessed by calculating Q10 values: the increase in respiration for a 10°C increase in temperature. Q10 was lowest under T and TP, and highest under P. Both ER and SR all had significantly positive correlation with soil moisture. Increased precipitation increased net ecosystem exchange and gross ecosystem productivity, whereas warming reduced them. The combination of warming and increased precipitation had an intermediate effect. Both net ecosystem exchange and gross ecosystem productivity were positively related to soil moisture and negatively related to soil and air temperature. These findings suggest that predicted climate change in this region, involving both increased precipitation and warmer temperatures, will increase the net ecosystem exchange in the Stipa steppe meaning that the ecosystem will fix more carbon.
Symbiont selection via alcohol benefits fungus farming by ambrosia beetles
Authors: Ranger Christopher M. , Biedermann Peter H. W. , Phuntumart Vipaporn , Beligala Gayathri U. , Ghosh Satyaki , Palmquist Debra E. , Mueller Robert , Barnett Jenny , Schultz Peter B. , Reding Michael E. , Benz J. Philipp
Published: April 2018

Significance

Ambrosia beetles are among the true fungus-farming insects and cultivate fungal gardens on which the larvae and adults feed. After invading new habitats, some species destructively attack living or weakened trees growing in managed and unmanaged settings. Ambrosia beetles adapted to weakened trees tunnel into stem tissues containing ethanol to farm their symbiotic fungi, even though ethanol is a potent antimicrobial agent that inhibits the growth of various fungi, yeasts, and bacteria. Here we demonstrate that ambrosia beetles rely on ethanol for host tree colonization because it promotes the growth of their fungal gardens while inhibiting the growth of “weedy” fungal competitors. We propose that ambrosia beetles use ethanol to optimize their food production.
Harmonics added to a flickering light can upset the balance between ON and OFF pathways to produce illusory colors
Authors: Rider Andrew T. , Henning G. Bruce , Eskew Rhea T. , Stockman Andrew
Published: April 2018

Significance

By varying the temporal waveforms of complex flickering stimuli, we can produce alterations in their mean color that can be predicted by a physiologically based model of visual processing. The model highlights the perceptual effects of a well-known feature of most visual pathways, namely the early separation of visual signals into increments and decrements. The role of this separation in improving the efficiency and sensitivity of the visual system has been discussed before, but its effect on perception has been neglected. The application of a model incorporating half-wave rectification offers an exciting psychophysical method for investigating the inner workings of the human visual system.
Programmed self-assembly of peptide–major histocompatibility complex for antigen-specific immune modulation
Authors: Mao Chih-Ping , Peng Shiwen , Yang Andrew , He Liangmei , Tsai Ya-Chea , Hung Chien-Fu , Wu T.-C.
Published: April 2018

Significance

T cells play a critical role in the control of diseases, ranging from infection to cancer. However, the activation of antigen-specific T cells against low-affinity antigens, such as tumor self-antigens, remains a challenge. Here, we report a technology for amplifying antigen-specific lymphocyte responses based on orchestrating coordinated signaling events at the level of peptide–major histocompatibility complex (pMHC)–TCR interactions. We engineered a soluble chimeric protein composed of annexin V (ANXA5) linked to pMHC. ANXA5 behaves as an anchor that facilitates stable, repeated cognate pMHC–TCR contacts and TCR cross-linking via programmed self-assembly. pMHC/ANXA5 fusion augments lymphocyte responses by several orders of magnitude and overcomes low-affinity pMHC–TCR interactions.
Neddylation mediates ventricular chamber maturation through repression of Hippo signaling
Authors: Zou Jianqiu , Ma Wenxia , Li Jie , Littlejohn Rodney , Zhou Hongyi , Kim Il-man , Fulton David J. R. , Chen Weiqin , Weintraub Neal L. , Zhou Jiliang , Su Huabo
Published: April 2018

Significance

Myocardium thickening at midgestation to late gestation is crucial for the formation of a functionally competent postnatal heart. However, posttranslational mechanisms regulating this process remain unexplored. Here, we uncover a critical role for the ubiquitin-like protein NEDD8 in heart development. By targeting the E1 enzyme that mediates the conjugation of NEDD8 to protein targets, we show that NEDD8 modification is essential for ventricular compaction and heart function. We further identify that the NEDD8 substrate Cullin 7 mediates the degradation of Hippo kinase Mst1, thereby enabling YAP signaling, cardiomyocyte proliferation, and proper heart development. These results reveal a posttranslational regulatory mechanism in ventricular wall maturation and may provide mechanistic insights into the etiology of left ventricular noncompaction cardiomyopathy.
Roles of the CSE1L-mediated nuclear import pathway in epigenetic silencing
Authors: Dong Qiang , Li Xiang , Wang Cheng-Zhi , Xu Shaohua , Yuan Gang , Shao Wei , Liu Baodong , Zheng Yong , Wang Hailin , Lei Xiaoguang , Zhang Zhuqiang , Zhu Bing
Published: April 2018

Significance

Regulators essential for facilitating gene silencing are interesting targets of epigenetic studies. Our work describes a regulator, CSE1L, that is essential for the silencing of many endogenous methylated genes. Depletion of CSE1L reactivates these genes without causing DNA demethylation. Interestingly, such reactivation is not due to a direct chromatin role of CSE1L. Instead, it depends on the role of CSE1L in importin-mediated protein nuclear transportation, which is confirmed by similar effects observed in cells depleted of other players in the same protein transportation pathway. Intriguingly, importin-mediated protein nuclear transportation preferentially facilitates gene silencing with specificity for a subset of genes, suggesting that the cargo specificity of protein nuclear import systems may impact the selectivity of gene regulation.
Facet-specific interaction between methanol and TiO
2
probed by sum-frequency vibrational spectroscopy
Authors: Yang Deheng , Li Yadong , Liu Xinyi , Cao Yue , Gao Yi , Shen Y. Ron , Liu Wei-Tao
Published: April 2018

Significance

Facet engineering has become a major strategy for designing crystalline catalysts, yet many fundamental issues, including facet-specific interaction with adsorbates, remain unsolved due to lack of experimental investigation. Using surface-specific sum-frequency vibrational spectroscopy, we have conducted an in-depth study of methanol adsorption on four different facets of TiO
2
under ambient conditions. The spectra revealed that for the four facets investigated, dissociation of adsorbed methanol occurs only when surface defects are present. Adsorption kinetics and energetics appeared nearly the same on different facets, but the Fermi resonance coupling strength for CH
3
of adsorbed methanol was found to depend sensitively on facets and methanol coverage, and could serve as a gauge for studying facet effects on molecular adsorption and surface reactions.
Crystal structure and mechanism of human carboxypeptidase O: Insights into its specific activity for acidic residues
Authors: Garcia-Guerrero Maria C. , Garcia-Pardo Javier , Berenguer Esther , Fernandez-Alvarez Roberto , Barfi Gifty B. , Lyons Peter J. , Aviles Francesc X. , Huber Robert , Lorenzo Julia , Reverter David
Published: April 2018

Significance

Carboxypeptidase O (CPO) is a membrane-anchored brush-border enzyme associated with the small intestinal phase of protein digestion with distinctive specificity toward acidic C-terminal (C-t) amino acids. The combined activity of human CPO (hCPO) and pancreatic carboxypeptidases enables the C-t proteolysis of the great majority of amino acids present in dietary proteins. Here we disclose mechanism and structures of hCPO, both ligand-free and -bound with a natural peptidic inhibitor ascribing the exquisite specificity toward C-t acidic residues to a single amino acid, Arg275, in the substrate-binding pocket. Mutations of this residue to Asp and Ala suffices to reverse the specificity to C-t basic and hydrophobic residues, respectively, and faithfully mirror the specificity variants (hCPB, hCPA1, hCPA2) in enzyme kinetic assays.
Yaḥyā Dawlatābādī’s Contribution to Persian Poetic Modernity
Authors: Ahmed Amr Taher
Published: April 2018

In 1912, Yaḥyā Dawlatābādī composed two poems, the form of which diverged greatly from the canonical rules of tradition. Both poems were based on syllabic meters. Critics and historians of modern Persian literature have given these poems little consideration, and discussed them merely from the point of view of metrics. When compared to the great modernist endeavors in the poetry of the time, these pieces were judged severely, or altogether disavowed. This paper aims to show that, beyond mere metrical audacity, Yaḥyā Dawlatābādī’s syllabic poems were in fact innovative. As the article argues, they were born out of the same quest for fresh poetic forms that induced contemporaneous modernists to create new, individualized poetic patterns.
Offspring Rivers of The United States
Authors: Sublett Michael D.
Published: April 2018

Streams are significant landmarks in the landscape, often acquiring their specific names before other surface features. In English, rivers stand at the apex of the stream hierarchy. This study looks at those rivers in the United States that have their headwaters, their origin points, at the places where two other rivers, of names different from the resulting river, end, like the Allegheny and Monongahela ceasing to exist downstream of the place where they unite to form the Ohio. An adapted term, offspring, was necessary to designate this special circumstance of what turned out to be 71 rivers in the United States.
On-site comparison of Quantum Hall Effect resistance standards of METAS and the BIPM: Ongoing key comparison BIPM.EM-K12
Authors: Gournay Pierre , Rolland Benjamin , Mortara Alessandro , Jeanneret Blaise
Published: April 2018

An on-site comparison of the quantum Hall effect (QHE) resistance standards of the Federal Institute of Metrology METAS (Switzerland) and of the Bureau International des Poids et Mesures (BIPM) was made in December 2017. Measurements of a 100 Ω standard in terms of the conventional value of the von Klitzing constant, R
K-90, agreed to 5 parts in 1010 with a relative combined standard uncertainty u
c = 23 × 10−10.

Scaling from 100 Ω to 10 kΩ has also been addressed through the measurement of a 10000 Ω/100 Ω ratio. The measurements carried out agreed to 2 parts in 1010 with a relative combined standard uncertainty u
c = 19 × 10−10.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).