bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainable production of ethylene from bioethanol over hierarchical ZSM-5 nanosheets
Authors: Shetsiri Sirawit , Thivasasith Anawat , Saenluang Kachaporn , Wannapakdee Wannaruedee , Salakhum Saros , Wetchasat Piraya , Nokbin Somkiat , Limtrakul Jumras , Wattanakit Chularat
Published: October 2018

Highly selective production of ethylene from bioethanol dehydration over hierarchical ZSM-5 nanosheets.
Dynamics of the floating nematic phase formation in platelet suspension with thickness polydispersity by sedimentation
Authors: Sui Jize , Doi Masao , Ding Yiming
Published: October 2018

An inverted phase coexistence, where an ordered phase appears on top of a disordered phase, has been observed in polydisperse colloidal suspensions.
Switchable electrorheological activity of polyacrylonitrile microspheres by thermal treatment: from negative to positive
Authors: Do Taegu , Ko Young Gun , Chun Youngsang , Jung Youngkyun , Choi Ung Su , Park Yong-Sung , Woo Je-Wan
Published: October 2018

The color change of polyacrylonitrile microspheres with thermal treatment temperature, and their positive- and negative-electrorheological behaviors.
Light-driven carbon dioxide reduction coupled with conversion of acetylenic group to ketone by a functional Janus catalyst based on keplerate {Mo132}
Authors: Lodh Joyeeta , Mallick Apabrita , Roy Soumyajit
Published: October 2018

A novel dual functional Janus catalyst {Mo132} for photocatalytic carbon dioxide reduction coupled with organic hydroxylation from phenylacetylene to acetophenone is reported.
A hot-electron-triggered catalytic oxidation reaction of plasmonic silver nanoparticles evidenced by surface potential mapping
Authors: Lee Seung-Hoon , Jo Jeong-Sik , Park Ju Hyeun , Lee Seung Woo , Jang Jae-Won
Published: October 2018

Electron's working as a majority carrier for the catalytic oxidation reaction of plasmonic silver nanoparticles is directly observed.
Achieving a high loading Si anode via employing a triblock copolymer elastomer binder, metal nanowires and a laminated conductive structure
Authors: Wei Difeng , Mao Jie , Zheng Zhenan , Fang Junjie , Luo Yingwu , Gao Xiang
Published: October 2018

A Si anode with a mass loading of 5.31 mg cm−2 was achieved via enhancing both ion and electron transportation in an electrode.
Rapid activation of Co3O4 cocatalysts with oxygen vacancies on TiO2 photoanodes for efficient water splitting
Authors: Dong Guojun , Hu Hongyan , Huang Xiaojuan , Zhang Yajun , Bi Yingpu
Published: October 2018

Herein, we demonstrate a rapid and highly efficient strategy for rationally constructing oxygen vacancies on Co3O4 cocatalysts by Ar-plasma treatment, and the photocurrent density could be achieved up to 2.5 mA cm−2 (1.23 VRHE) under AM 1.5G irradiation (100 mW cm−2).
Photocatalysis in an evanescent field: an in situ approach to studying photocatalytic performance by tracing interfacial refractive index changes and kinetics
Authors: Huang Yunyun , Xiao Aoxiang , Hou Guanhua , Li Hongtao , Guo Tuan , Guan Bai-Ou
Published: October 2018

An in situ strategy to understand the photocatalytic performance of Cu2O–Ag@rGO nanocomposites through interfacial photocatalysis on an optical microfiber has been demonstrated.
Photoluminescent and pH-responsive supramolecular structures from co-assembly of carbon quantum dots and zwitterionic surfactant micelles
Authors: Sun Xiaofeng , Chen Mengjun , Zhang Yiqiang , Yin Yanji , Zhang Linwen , Li Hongguang , Hao Jingcheng
Published: October 2018

Mixing negatively charged carbon quantum dots with a zwitterionic surfactant in water produces a variety of supramolecular structures, which are photoluminescent and show a reversible response to pH.
Rational design of coralloid Co9S8–CuS hierarchical architectures for quantum dot-sensitized solar cells
Authors: Hong Xiaodan , Liu Qun , Gao Xiaoyue , He Chunfeng , You Xingyan , Zhao Xin , Liu Xiangyang , Ye Meidan
Published: October 2018

Coralloid Co9S8–CuS hierarchical structures with high stability and remarkable electrochemical activity in QDSCs are firstly in situ grown on FTO substrates, which are also applicative on other flexible conductive substrates for potential applications in wearable devices.
An efficient code to solve the Kepler equation
Authors: Raposo-Pulido V. , Peláez J.
Published: October 2018

Context. This paper introduces a new approach for solving the Kepler equation for hyperbolic orbits. We provide here the Hyperbolic Kepler Equation–Space Dynamics Group (HKE–SDG), a code to solve the equation.

Methods. Instead of looking for new algorithms, in this paper we have tried to substantially improve well-known classic schemes based on the excellent properties of the Newton–Raphson iterative methods. The key point is the seed from which the iteration of the Newton–Raphson methods begin. If this initial seed is close to the solution sought, the Newton–Raphson methods exhibit an excellent behavior. For each one of the resulting intervals of the discretized domain of the hyperbolic anomaly a fifth degree interpolating polynomial is introduced, with the exception of the last one where an asymptotic expansion is defined. This way the accuracy of initial seed is optimized. The polynomials have six coefficients which are obtained by imposing six conditions at both ends of the corresponding interval: the polynomial and the real function to be approximated have equal values at each of the two ends of the interval and identical relations are imposed for the two first derivatives. A different approach is used in the singular corner of the Kepler equation – |M| < 0.15 and 1 < e <  1.25 – where an asymptotic expansion is developed.

Results. In all simulations carried out to check the algorithm, the seed generated leads to reach machine error accuracy with a maximum of three iterations (∼99.8% of cases with one or two iterations) when using different Newton–Raphson methods in double and quadruple precision. The final algorithm is very reliable and slightly faster in double precision (∼0.3 s). The numerical results confirm the use of only one asymptotic expansion in the whole domain of the singular corner as well as the reliability and stability of the HKE–SDG. In double and quadruple precision it provides the most precise solution compared with other methods.
Impact of binary interaction on the evolution of blue supergiants
Authors: Farrell E. J. , Groh J. H. , Meynet G. , Kudritzki R. , Eldridge J. J. , Georgy C. , Ekström S. , Yoon S.-C.
Published: October 2018

A large fraction of massive stars evolve in interacting binary systems, which dramatically modifies the outcome of stellar evolution. We investigated the properties of blue supergiants in binary systems and whether they are suitable for extragalactic distance determinations using the flux-weighted gravity luminosity relationship (FGLR). This is a relationship between the absolute bolometric magnitude Mbol and the spectroscopically determined flux-weighted gravity gF = g/T4eff, where g is the surface gravity and Teff is the effective temperature. We computed a grid of binary stellar evolution models with MESA and use the v2.1 BPASS models to examine whether they are compatible with the relatively small scatter shown by the observed relationship. Our models have initial primary masses of 9–30 M⊙, initial orbital periods of 10–2511 days, mass ratio q = 0.9, and metallicity Z = 0.02. We find that the majority of primary stars that produce blue supergiant stages are consistent with the observed FGLR, with a small offset towards brighter bolometric magnitudes. In between 1%–24% of cases, binary evolution may produce blue supergiants after a mass transfer episode, that lie below the observed FGLR. A very small number of such stars have been found in extragalactic FGLR studies, suggesting that they may have evolved through binary interaction. Some models with shorter periods could resemble blue hypergiants and luminous blue variables. We used CMFGEN radiative transfer models to investigate the effects of unresolved secondaries on diagnostics for Teff and g, and the biases on the determination of interstellar reddening and Mbol. We find that the effects are small and within the observed scatter, but could lead to a small overestimate of the luminosity, of Teff and of g for extreme cases. We conclude that the observed FGLR can, in principle, be well reproduced by close binary evolution models. We outline directions for future work, including rotation and binary population synthesis techniques.
Zum Einfluss von Körpermaßen der Eltern auf das Geburtsgewicht von eutrophen Termingeborenen (TG) unter besonderer Berücksichtigung der Körperhöhe und des Körpergewichts des Vaters
Authors: Olbertz Dirk , Pippig Stanley , Hesse Volker , Schwab Karl , Wittwer-Backofen Ursula , Hentschel Roland , Voigt Manfred
Published: October 2018

Zur Bestimmung des quantitativen Einflusses der Körpermesswerte von Mutter und Vater auf das Geburtsgewicht Neugeborener wurden im Rahmen einer Multizenterstudie an 10 deutschen Geburtskliniken das Geburtsgewicht von 1312 eutrophen Termingeborenen sowie die Körperhöhe und das Körpergewicht ihrer Eltern erfasst. Auch wenn man die Körperhöhe der Väter von 176–184 cm mit einem Körpergewicht von 76–84 kg relativ konstant hält, liegen die Geburtsgewichte bei größeren Müttern höher als bei kleineren. Hinsichtlich Körpergewicht der Mutter und Geburtsgewicht zeigt sich ebenfalls ein deutlicher Anstieg des Geburtsgewichtes bei steigendem Körpergewicht der Mutter. Hält man hier Körperhöhe (164–172 cm) und Körpergewicht (56–64 kg) der Mutter konstant, so steigen auch hier die Geburtsgewichte deutlich mit der Körperhöhe des Vaters an. Ein signifikanter Beitrag des Körpergewichtes des Vaters zum Geburtsgewicht ist nicht zu erkennen. Aus der multivariablen Regressionsanalyse wurde folgende Rangfolge für die Einflussfaktoren Körperhöhe und Körpergewicht der Eltern auf das Geburtsgewicht ihrer Neugeborenen ermittelt: 1.: Körperhöhe der Mutter, 2.: Körpergewicht der Mutter, 3.: Körperhöhe des Vaters. Bei der Beurteilung des somatischen Entwicklungsstandes der Neugeborenen, sollten neben der Körperhöhe und Körpergewicht der Mutter auch die Körperhöhe des Vaters herangezogen werden.
(Diacetoxyiodo)benzene-Mediated Transition-Metal-Free Amination of C(sp3)–H Bonds Adjacent to Heteroatoms with Azoles: Synthesis of N-Alkylated Azoles
Authors: Jin Can , Su Weike , Sun Bin , Yan Zhiyang
Published: October 2018

A novel PhI(OAc)2-mediated cross-dehydrogenative coupling reaction of α-C(sp3)–H bonds adjacent to a hetero atom with various azoles has been developed, which provides an alternative method for constructing C–N bonds with high atom efficiency. This new protocol requires no metal catalyst and it provides ready access to a wide range of N-alkylated azole derivatives in moderate to excellent yields by using commercially available PhI(OAc)2 as the sole oxidant. Furthermore, the method is effective on a gram scale, which highlights the practicality of this transformation. The result of radical-captured experiments indicated that the transformation might involve a free-radical pathway.
Trochlear Nerve Repair during Retrosigmoid Suprameatal Approach for Petrotentorial Meningioma: Operative Video
Authors: Matsushima Ken , Kohno Michihiro , Nakajima Nobuyuki , Ichimasu Norio
Published: October 2018

When operating on difficult skull base lesions, it is essential to be able to handle unexpected intraoperative findings or troubles, while achieving maximal lesion removal and minimal functional deficit. This video demonstrates a case of trochlear nerve repair that was performed during the retrosigmoid suprameatal approach for treatment of a petrotentorial meningioma, extending into the Meckel's cave. The patient is a 47-year-old woman with a right petrotentorial meningioma, extending into the Meckel's cave. The retrosigmoid suprameatal approach was performed with preservation of the superior petrosal vein. However, a divided trochlear nerve was incidentally found during tumor resection. We hence carefully dissected both nerve ends from the tumor without shortening their lengths, and repaired them by end-to-end anastomosis, using fibrin glue without any graft materials. The tumor was removed completely and the patient's preoperative facial sensory impairment disappeared after the surgery. The patient's facial sensory impairment disappeared completely, but she had transient diplopia after the surgery. However, the newly developed diplopia resolved completely, and she had no neurological deficits or tumor recurrence during the follow-up period of 1-year.

The link to the video can be found at: https://youtu.be/g-B-w_zDudg.
A Cephalometric Study to Evaluate the Variations in Pharyngeal Airway Spaces in Class I and Class II Malcocclusions
Authors: Sandhu Navreet , Sandhu Sarabjeet , Mehta Kavita , Kashyap Rita
Published: October 2018

Introduction: Ever since the time of Edward H. Angle, the effects of upper airway obstruction have been recognized in the field of craniofacial biology. Because of the close relationship between the pharynx and the dentofacial structures, a mutual interaction is expected to occur between the pharyngeal structures and the dentofacial pattern, and therefore justifies orthodontic interest. The purpose of this study was to compare the upper and lower pharyngeal widths and nasopharyngeal area in class I and class II malocclusion patients. Methods: The study sample consisted of 48 subjects of age group 18-26 years, divided into 2 groups : class I(n=24) and class II(n=24). Pharyngeal airways were assessed according to Mc Namara's analysis and Handelman and Osborne method of measuring pharyngeal widths and nasopharyngeal areas. Results: Independent t –test showed a statistically significant difference (p<0.01) in upper aerial width and nasopharyngeal airway area between two groups, showing that in class II cases upper aerial width is narrower and nasopharyngeal area is small when compared to class I cases. Conclusion: Conclusion of the study was that upper aerial width and nasopharyngeal airway area of class II cases were smaller than Class I cases. It was observed that mandibular position with respect to cranial base had an effect on pharyngeal airway.
Dentin Tubular Occlusion with Bioactive Glass Containing Dentrifice and Gluma Desensitizer–A Comparative Sem Evaluation
Authors: Gupta Ashu , Sharma Neha , Bramta Manmohan
Published: October 2018

Dentinal hypersensitivity (DH) is a painful clinical condition and is characterized by pain arising from exposed dentin in response to various stimuli. Various treatment modalities are available to treat dentinal hypersensitivity which include at-home and in-office treatment. At home treatment generally consists of a variety of dentrifices containing different constituents like stannous fluoride, strontium chloride and potassium oxalate. These agents cause occlusion of dentinal tubules which decreases both dentine permeability and fluid movement thereby reducing hypersensitivity. Recently, bioactive glass (NovaMin) has been incorporated as a remineralising ingredient in dentifrice formulations for treating Dentinal Hyprsensitivity. It relieves the symptoms by precipitating hydroxycarbonate apatite (HCA) onto the tooth surface. Another combination product consisting of an aqueous solution of 5% glutaraldehyde and 35% hydroxyethyl methacrylate (Gluma desensitizer) has also been reported to be an effective desensitizing agent. Thus, the aim of the study was to evaluate and compare the tubule occluding effect of of two desensitizing agents, which are bioactive glass (Novamin), and Gluma Desensitizer. In the present study bioactive glass was found to produce more completely occluded tubules while Gluma desensitizer caused more partial occlusion on initial application. Hence, NovaMin application could be more effective in providing relief from dentinal hypersensitivity when compared with Gluma Desensitizer.
Removable or Fixed??? Force is in the Hands of Orthodontist not Appliance
Authors: Gupta Garima , Goyal Sachin
Published: October 2018

Objective: To present a new, simple and economical appliance for bringing a palatally impacted canine into the oral cavity. Material and methods-The basic appliance design incorporatesAdams clasps, usually on both first molars, a posterior bite block and bow of 0.8 mm wire with a stainless steel tubing (to increase the strength) with a helix at the open end, to wear an elastic from attachment on the tooth. Results: Treatment resulted in the eruption of left canine till the occlusal level in the oral cavity through the attached mucosa and simultaneous correction of rotated right canine, with coinciding midlines and no mandibular shift. Conclusion: The simple upper removable appliance can be used as an excellent method of treating palatally impacted canines.
Comparison of ISO Method with Two New Methods for Determining the Radio-Opacity of Restorative Resins.
Authors: Kapila Rishabh , Matsuda Yukiko , Nishikawa Keiichi , Sano Tsukasa
Published: October 2018

Objective: To evaluate alternate methods for determining the radio-opacity of restorative resins. Materials and Methods: Disks of five restorative resins were made and placed on the sensor of intraoral X-ray sensor. Exposures were made and the images were generated without using automatic gain control and exported as DICOM files. Gray values were measured from these images using Image-J software. Results: These gray values were used to estimate the equivalent aluminium thickness in mm using the ISO method and using methods described by Vivian et al and Lachowski et al. The equivalent aluminium values obtained from ISO method was statistically compared to the other two methods using ANOVA and Dunnet's test. The level of significance was set at p <0.05. A statistical significant difference was seen for the 2nd method. However, no statistical differences were seen for the 3rd method. Conclusion: The alternate methods are relatively simple to use, non-time consuming, and need no special softwares for calculations.
A Comparative Evaluation of Microleakage of Glass Ionomer Restoration with Different Surface Protectors - an In-Vitro Study
Authors: Ninawe Nupur , Nayak Ullal , Nagar Priya , Khandelwal Vishal , Jain Suyash , Gupta Ambika
Published: October 2018

Aim: All the restorative material whatsoever introduced till-date have an inherent disadvantage of micro-leakage measurable different grades. The present study comparatively evaluates the micro-leakage of glass ionomer restoration with different surface protection methods. Methodology: 36 premolars were obtained without any cracks or restorations for the study. Teeth were stored in distilled water containing thymol crystals till the beginning of the study. The teeth were randomly divided into 3 groups based on surface protectors used. Group I is GC Fuji Varnish, Group II is vaseline and Group III is G-Coat plus along with GIC restoration. Class V cavities were prepared of dimensions mesio-distal width of 3 mm, occluso-gingival length of 2 mm, and a depth of 1.5 mm on buccal and lingual surfaces with a high-speed hand-piece with air-water spray. Results: Kruskal- Wallis test was applied and Vaseline group showed significantly less micro-leakage compared to G-Coat plus i.e. G-Coat plus exhibited significantly higher microleakage compared to other groups. Conclusion: Evaluation of micro-leakage of glass ionomer cements using various surface protecting agents, Vaseline was considered the best surface protecting agent maintaining the water balance and showing no micro-leakage.
Adsorption characteristics of epigenetically modified DNA nucleobases on single-layer MoS2: A first-principles study
Authors: Tabatabaei Seyed-Mohammad , Pourfath Mahdi , Fathipour Morteza
Published: October 2018

We report a comprehensive van der Waals density functional theory study on the adsorption characteristics of four canonical and six epigenetically modified DNA nucleobases on single-layer molybdenum disulfide (SL-MoS2) substrates. All the considered nucleobases are physisorbed on SL-MoS2 with a modest electron transfer, ranging from 0.007e− to 0.041e−, from the adsorbates to SL-MoS2. Upon the physisorption of adenine, cytosine, guanine, and thymine on the SL-MoS2 sheet, the work function is decreased by 0.29, 0.09, 0.54, and 0.01 eV, respectively. It is shown that the bandgap of SL-MoS2 can be significantly reduced, by as much as 30%, through the adsorption of nucleobase molecules as the induced molecular flat bands tend to appear either in the energy gap region or in the vicinity of the valence band maximum. We unfold the emergence of distinct electron energy loss spectra upon nucleobase adsorption which may serve as potential probes for selective detection of nucleobase molecules in prospective DNA sequencing applications based on SL-MoS2.
SIESTA: A high current ion source for erosion and retention studies
Authors: Arredondo R. , Oberkofler M. , Schmid K. , Schwarz-Selinger T. , Jacob W. , Neu R.
Published: October 2018

Second ion experiment for sputtering and TDS analysis is a high-current ion source for erosion and retention studies with focus on wall materials for fusion devices. The system is composed of a DuoPIGatron type ion source, three consecutive grids for ion extraction, acceleration and beam focusing, a differential pumping stage, a dipole magnet for mass filtering, a quadrupole doublet lens, a target chamber, a load-lock, and a chamber for thermal desorption spectrometry. The acceleration potential of the source can be varied between 500 V and 10 kV. The target chamber has a base pressure of 10−8 mbar and an operating pressure of 5 × 10−7 mbar. The target can be rotated to study angle-dependent effects and can be heated via electron-impact heating up to 1300 K for high temperature erosion and implantation studies. The target chamber is equipped with an in situ magnetic suspension balance. The operating parameters of the ion source were mapped to achieve the maximum ion current at the target for various gas species and accelerating potentials. The beam emittance for a D3+ ion beam was measured after deflection in the dipole magnet. This was used for ion beam simulations, which were instrumental for the design of the quadrupole lenses. If the quadrupole doublet is used, the ion flux to the target is increased by up to a factor of 4. Additionally, the relative population of neutral particles present in the beam at the target was quantified and is equal to 0.8% when averaged over the measurement positions. The typical beam footprint at the target under normal incidence has an area of 0.5 cm2. The ion current reaching the target increases with the accelerating potential. Due to this effect, the ion flux density at the target in the low-ion-impact-energy range can be increased by operating the source at a higher extraction potential and by applying a (decelerating) potential to the target. Ion impact energies as low as 200 eV/D are achieved this way with a D3+ current of 100 μA when focusing the beam with the quadrupole doublet lens, equating to a D particle flux density of 3.7 × 1019 m−2 s−1. At ion impact energies of 2 keV/D, the maximum achievable flux density with D3+ is 6 × 1019 D m−2 s−1. Experimental determination of sputter yields was performed via ex situ weight loss measurement for bulk Au samples, showing reasonably good agreement with simulations and experimental data from the literature.
A multichannel gated neutron detector with reduced afterpulse for low-yield neutron measurements in intense hard X-ray backgrounds
Authors: Abe Y. , Nakajima N. , Sakaguchi Y. , Arikawa Y. , Mirfayzi S. R. , Fujioka S. , Taguchi T. , Mima K. , Yogo A. , Nishimura H. , Shiraga H. , Nakai M.
Published: October 2018

A design of multichannel gated photomultiplier tube (PMT) is presented for the 960-channel neutron time-of-flight detector at the Institute of Laser Engineering of Osaka University. This is important for the fusion science and the nuclear photonics where intense hard X-rays are generated from the interaction of ultra-short laser pulse of petawatt power density with matter. The hard X-rays often overload PMTs and cause signal-induced background noises called afterpulses, making the detection of subsequent neutrons impossible. For this reason, the PMTs are coupled with an electrical time-gating (ETG) system to avoid overloading. The ETG system disables the PMT by modulating the dynode potential during the primary X-ray flash. An after-pulsing suppression technique is demonstrated by applying a reverse bias voltage between the photocathode and the first dynode. The presented multichannel scheme provides a gate response time of 80 ns, a signal cutoff ratio of 2.5 × 102, and requires reasonably low power consumption.
A simple and versatile machine for creep testing at low loads (6–300 N) and on miniaturized specimens: Application to a Mg-base alloy
Authors: Koundinya N. T. B. N. , E Nandha Kumar , Chawake Niraj , Korla Rajesh , Kottada Ravi Sankar
Published: October 2018

High temperature creep testing at a very low load range (<10 N) on miniaturized specimens has always been a challenge due to inherent design limitation (such as significant preload) of the conventional creep testing machines. In the present study, the challenge was overcome by developing a simple and versatile horizontal creep testing machine to conduct creep tests in the loading range of ∼6–300 N in tension and in compression. The competence of the in-house-built horizontal creep machine was validated by conducting creep testing on dog-bone shaped sheet specimens of cast Mg-1Sn-1Ca (TX11) Mg-base alloy over a lower stress range of 1.6–5.9 MPa (equivalent load range of 6.4–18.1 N) at 450 °C and in the high stress range of 20–80 MPa (equivalent load range of 76–310 N) at 175 °C.
Favoritism of quantum dot inter-Coulombic decay over direct and multi-photon ionization by laser strength and focus
Authors: Haller Anika , Bande Annika
Published: October 2018

We study the dynamics of a two-electron system undergoing resonant excitation and inter-Coulombic decay (ICD) in a pair of quantum dots. The influence of the focus of the exciting laser on the ICD process is investigated for a π-pulse with a close look on competing processes, i.e., direct ionization and multi-photon excitations. We scan through the field strength up to six Rabi cycles to show that ICD is still verifiable after several population inversions. With novel analyses, we determine for the first time populations of the different continuum states and thus conclude on the importance of several multi-photon excitation channels. Finally, we look into the influence of complex absorbing potentials on the dynamics.
An optimal low power digital controller for portable solar applications
Authors: Vijayalakshmi N. , Maruthupandi P.
Published: October 2018

The design of controllers for solar energy harvesting systems plays the key role in deciding the efficiency of the energy utilized. In applications of energy scavenging, the harvested power is consumed for about 70% in the operation of the converter and controller blocks before being supplied to the load. The proposed optimal Field Programmable Gate Array based Load Predictive Maximum Power Point Tracking (LP_MPPT) Digital Controller is used for low power, speedy, and decisive energy scavenging systems for a long run in applications of wireless or remote sensing or portable. LP_MPPT helps to predict the need of the load and generate the converter output as buck/boost/buck_boost mode power in comparison to the input from solar panels for every clock cycle. The power consumption of the controller section is comparatively reduced as the buck_boost mode of operation utilizes the no operation state. The proposed methodology is simulated and implemented using Xilinx ISE Design Suite 12.1 which is supported by the family SPARTAN 3E. The simulation results thus obtained show an increase in efficiency (94.3%) with trade off factors, namely, speed and area.
Electrically triggered insulator-to-metal phase transition in two-dimensional (2D) heterostructures
Authors: Grisafe Benjamin , Zhao Rui , Ghosh Ram Krishna , Robinson Joshua A. , Datta Suman
Published: October 2018

We evaluate the heterogeneous integration of the layered correlated electron material, 1T-TaS2, on semiconducting 2H-MoS2 for the realization of an all two-dimensional insulator-to-metal (IMT) phase transition device. First principles calculations investigate the band structure of the resulting heterostructure and confirm the existence of a charge density wave (CDW)-based bandgap. 1T-TaS2 films are synthesized via powder vapor deposition on monolayer MoS2 substrates and shown to exhibit CDW induced IMT phase transitions. Both Raman and electrical measurements display reversible commensurate to nearly commensurate CDW IMT phase transitions. Finally, a phase transition transistor device is demonstrated that harnesses the electrically triggered abrupt IMT in 1T-TaS2 and semiconducting properties of 2H-MoS2.
Relative equilibria of point vortices and linear vortex sheets
Authors: O’Neil Kevin A.
Published: October 2018

A new exact method is presented for obtaining uniformly rotating distributions of vorticity in a two dimensional ideal fluid. The vorticity is confined to the union of a straight line and a finite collection of points; i.e., the distribution is a collection of point vortices together with a number of vortex sheets lying on the common line. The vorticity density of the vortex sheets and the velocity field of the fluid are expressed in terms of a rational function in which the point vortex positions and strengths appear as parameters. For many values of these parameters, the vortex sheet portion of the distribution is not unique, and there is a continuous family of vortex sheets which combine with the point vortices to form relative equilibria. Several examples are worked out in detail.
Interplay of synergy and redundancy in diamond motif
Authors: Biswas Ayan , Banik Suman K
Published: October 2018

The formalism of partial information decomposition provides a number of independent components which altogether constitute the total information provided by the source variable(s) about the target variable(s). These non-overlapping terms are recognized as unique information, synergistic information, and redundant information. The metric of net synergy conceived as the difference between synergistic and redundant information is capable of detecting effective synergy, effective redundancy, and information independence among stochastic variables. The net synergy can be quantified using appropriate combinations of different Shannon mutual information terms. The utilization of the net synergy in network motifs with the nodes representing different biochemical species, involved in information sharing, uncovers rich store for exciting results. In the current study, we use this formalism to obtain a comprehensive understanding of the relative information processing mechanism in a diamond motif and two of its sub-motifs, namely, bifurcation and integration motif embedded within the diamond motif. The emerging patterns of effective synergy and effective redundancy and their contribution toward ensuring high fidelity information transmission are duly compared in the sub-motifs. Investigation on the metric of net synergy in independent bifurcation and integration motifs are also executed. In all of these computations, the crucial roles played by various systemic time scales, activation coefficients, and signal integration mechanisms at the output of the network topologies are especially emphasized. Following this plan of action, we become confident that the origin of effective synergy and effective redundancy can be architecturally justified by decomposing a diamond motif into bifurcation and integration motif. According to our conjecture, the presence of a common source of fluctuations creates effective redundancy. Our calculations reveal that effective redundancy empowers signal fidelity. Moreover, to achieve this, input signaling species avoids strong interaction with downstream intermediates. This strategy is capable of making the diamond motif noise-tolerant. Apart from the topological features, our study also puts forward the active contribution of additive and multiplicative signal integration mechanisms to nurture effective redundancy and effective synergy.
Emission of fast ions from conical wire array Z-pinches studied at different background pressures
Authors: Muñoz-Cordovez Gonzalo , Veloso Felipe , Valenzuela-Villaseca Vicente , Vescovi Milenko , Useche Wilmer , Wyndham Edmund , Favre Mario
Published: October 2018

A series of experimental measurements of fast ions generated in a tungsten conical wire array are presented. The ions are detected using a set of negatively biased Faraday cups located on axis above the array at distances between 10 and 67 cm. Significant differences in the signals from the probes are found on varying the background atmospheric pressure between 10−2 and 10−5 Torr. At 10−5 Torr, a pulse of ions moving at 106 m/s is collected by the cups. In contrast, at intermediate (10−4 Torr) and high (10−2 Torr) pressures, both electrons and ions are detected with a velocity of order 106 m/s. The differences with pressure are ascribed to the ionization of the background gas by the tungsten ions. Time-of-flight measurements show the emission of fast ions during the ablation phase of wire array dynamics. Comparing the temporal behavior of the ions and their velocity of propagation with the dynamics observed using UltraViolet / eXtreme UltraViolet imaging allows us to conclude that the ions and the dense plasma jet are different phenomena. Moreover, the application of a transverse electric field establishes the presence of massive ions in the outflow, suggesting also the presence of MeV tungsten ions with ionization of five or less. The observation of a fast particle outflow from a conical wire array and a possible ejection mechanism is discussed.
High spatial coherence in multiphoton-photoemitted electron beams
Authors: Meier Stefan , Higuchi Takuya , Nutz Manuel , Högele Alexander , Hommelhoff Peter
Published: October 2018

Nanometer-sharp metallic tips are known to be excellent electron emitters. They are used in highest-resolution electron microscopes in cold field emission mode to generate the most coherent electron beam in continuous-wave operation. For time-resolved operation, sharp metal needle tips have recently been triggered with femtosecond laser pulses. We show here that electrons emitted with near-infrared femtosecond laser pulses at laser oscillator repetition rates show the same spatial coherence properties as electrons in cold field emission mode in cw operation. From electron interference fringes, obtained with the help of a carbon nanotube biprism beam splitter, we deduce a virtual source size of less than (0.65 ± 0.06) nm for both operation modes, a factor of ten smaller than the geometrical source size. These results bear promise for ultrafast electron diffraction, ultrafast electron microscopy, and other techniques relying on highly coherent and ultrafast electron beams.
Conformational properties of an artificial GM1 glycan cluster based on a metal-ligand complex
Authors: Tachi Yuhei , Okamoto Yuko , Okumura Hisashi
Published: October 2018

An artificial glycan cluster, in which 24 monosialotetrahexosylganglioside (GM1) glycans are transplanted to the interface of a metal-ligand complex, was recently proposed to investigate the interaction between GM1 glycan clusters and amyloidogenic proteins by NMR analysis. In this study, all-atom molecular dynamics simulations were performed to characterize the conformational properties of the artificial GM1 glycan cluster. We found that more than 65% of GM1 glycans are clustered by interchain hydrogen bonds. Interchain hydrogen bonds are mainly formed between Neu5Ac and Gal’. Pentamers were most frequently observed in the metal-ligand complex. GM1 glycans are tilted and hydrophobically interact with ligand moieties. The hydrophobic surface of the metal-ligand complex increases intrachain hydrogen bonds in each conformation of the GM1 glycans. The increase of intrachain hydrogen bonds stabilizes the local minimum conformations of the GM1 glycan in comparison with the monomeric one. Interchain hydrogen bonding between glycans and glycan-ligand hydrophobic interactions also contribute to this conformational stabilization. Our results provide the physicochemical properties of the new artificial GM1 glycan cluster under the thermal fluctuations for understanding its protein recognition and designing the drug material for amyloidogenic proteins.
Note: Internal diamagnetic flux measurements on ASDEX Upgrade
Authors: Giannone L. , Fischer R. , Fuchs J. C. , Geiger B. , Maraschek M. , Rittich D. , Sieglin B. , Bock A. , Hobirk J. , Kallenbach A. , Mertens V. , Schuhbeck K. H. , McCarthy P. J.
Published: October 2018

Internal diamagnetic flux measurements, with measurement loops and compensation magnetic probes inside the vacuum vessel, are now available on the ASDEX Upgrade tokamak. The measured diamagnetic flux is compared to that predicted by simulations and calculated from equilibrium reconstruction. The diamagnetic flux measured at 2 positions separated toroidally by 180° in the vacuum vessel is compared.
Reducing the sensitivity of semiconductor ring lasers to external optical injection using selective optical feedback
Authors: Khoder Mulham , Van der Sande Guy , Verschaffelt Guy
Published: October 2018

We numerically investigate the influence of an integrated filtered optical feedback on the behavior of a semiconductor ring laser subject to external optical injection. The optical injection is spectrally directed at one of the non-lasing longitudinal modes of the laser. This so-called side-mode injection can cause wavelength switching, directional switching, and changes in the dynamical regime of the semiconductor ring laser. Such changes are often unwanted as they can affect the stability and the performance of the semiconductor ring laser. We investigate to what extent these undesired effects can be avoided by stabilizing the laser using on-chip filtered feedback. A two-directional mode model is used to investigate the dynamical behavior of the semiconductor ring laser under the simultaneous effect of the external optical injection and the integrated feedback. The results show that on-chip filtered optical feedback can be used to reduce the sensitivity of the semiconductor ring laser to external optical injection.
Nonlinear optical absorption of beryllium isoelectronic centers doped in silicon waveguides
Authors: Sumikura Hisashi , Kuramochi Eiichi , Notomi Masaya
Published: October 2018

Impurities provide host materials with additional optical functionalities. In this study, we observed the nonlinear optical absorption of beryllium isoelectronic centers (Be-IECs) doped in silicon waveguides (WGs) with optical population control of their bound exciton states. The optimized fabrication based on ion implantation and rapid thermal annealing achieved Be-IEC doping with a high concentration. The bound exciton state localized at the doped Be-IECs shows a photoluminescence peak and optical absorption simultaneously at a wavelength of 1150 nm. Nonresonant optical pumping at a power of ∼70 μW reduces the optical absorption coefficient of a Be-doped WG by 1.3 cm−1, which is one third of the intrinsic absorption. This significant reduction is attributed to the suppression of the absorption transition to the discrete bound exciton state filled by optical pumping. The nonlinear optical absorption of these impurity centers makes it possible to expand the potential application of Si-based photonic devices for enabling all-optical switching with lower optical power.
Synthesis of phase pure vanadium dioxide (VO2) thin film by reactive pulsed laser deposition
Authors: Bhardwaj Devanshi , Goswami Ankur , Umarji A. M.
Published: October 2018

Thin films of phase pure VO2 (M1 phase) are deposited on thermally grown oxide (Si/SiO2) substrate by reactive pulsed laser deposition of vanadium metal target. The influence of deposition parameters is studied by varying oxygen partial pressure while keeping other parameters constant. A thin film obtained at 50 mTorr is found to be phase pure by XRD and Raman spectral studies. SEM and AFM studies show smooth morphology with a surface roughness of 3–5 nm. The quality of the thin film was further established by characterizing the 68 °C (TSMT) transition by 2–3 orders of jump in resistance and a 60% change in reflectivity with minimum hysteresis. This single step process of deposition would be a suitable method for fabricating devices for smart window and metamaterial applications.
Passive subharmonic elimination
Authors: Culver D. , Mann B. P. , Stanton S. C.
Published: October 2018

This paper investigates an approach to passively eliminate subharmonic responses in nonlinear oscillators forced at resonance. A general framework is developed for identifying asymptotic levels where parameter values can be passively tuned to achieve dynamic cancellation of subharmonics. The results apply to oscillators with an arbitrary nonlinear structure. Due to its breadth of application from atomic force microscopy to aeromechanics, the methodology is demonstrated using a reduced-order model for an inextensible cantilevered beam carrying a concentrated mass. The concentrated mass provides a simple opportunity to vary parameters to achieve subharmonic elimination characteristics. Nonlinear simulation results indicate that parameter choices derived from the perturbation scheme are robust for a significant range of forcing amplitudes. Limits of the harmonic elimination and the sensitivity of the result to control parameters are discussed as well.
Proposal of a femtosecond megahertz repetition-rate electron diffraction instrument based on the Chinese Academy of Engineering Physics terahertz free electron laser beamline
Authors: Zhou Zheng , Wu Dai , Chen Han , Du Yingchao , Huang Wenhui , Li Ming
Published: October 2018

We report the design and optimization of a femtosecond electron diffraction instrument with megahertz repetition-rate. The proposed instrument is mainly based on the photoinjector of the Chinese Academy of Engineering Physics Terahertz free electron laser facility, which merges a 320 kV DC photocathode gun with two 4-cell super-conducting linac operating at 1.3 GHz. Simulations show that high quality electron probes with fC charge, ultralow emittance, and femtosecond scale bunch duration can be generated. Together with the capability of operating at continuous wave mode, this instrument is well matched with the demand of future electron diffraction.
Demonstration of femtosecond X-ray pump X-ray probe diffraction on protein crystals
Authors: Opara Nadia L. , Mohacsi Istvan , Makita Mikako , Castano-Diez Daniel , Diaz Ana , Juranić Pavle , Marsh May , Meents Alke , Milne Christopher J. , Mozzanica Aldo , Padeste Celestino , Panneels Valérie , Sikorski Marcin , Song Sanghoon , Stahlberg Henning , Vartiainen Ismo , Vera Laura , Wang Meitian , Willmott Philip R. , David Christian
Published: October 2018

The development of X-ray free-electron lasers (XFELs) has opened the possibility to investigate the ultrafast dynamics of biomacromolecules using X-ray diffraction. Whereas an increasing number of structures solved by means of serial femtosecond crystallography at XFELs is available, the effect of radiation damage on protein crystals during ultrafast exposures has remained an open question. We used a split-and-delay line based on diffractive X-ray optics at the Linac Coherent Light Source XFEL to investigate the time dependence of X-ray radiation damage to lysozyme crystals. For these tests, crystals were delivered to the X-ray beam using a fixed-target approach. The presented experiments provide probe signals at eight different delay times between 19 and 213 femtoseconds after a single pump event, thereby covering the time-scales relevant for femtosecond serial crystallography. Even though significant impact on the crystals was observed at long time scales after exposure with a single X-ray pulse, the collected diffraction data did not show significant signal reduction that could be assigned to beam damage on the crystals in the sampled time window and resolution range. This observation is in agreement with estimations of the applied radiation dose, which in our experiment was clearly below the values expected to cause damage on the femtosecond time scale. The experiments presented here demonstrate the feasibility of time-resolved pump-multiprobe X-ray diffraction experiments on protein crystals.
Large anisotropy in conductivity of Ti2O3 films
Authors: Yoshimatsu K. , Kurokawa H. , Horiba K. , Kumigashira H. , Ohtomo A.
Published: October 2018

We investigated electronic properties of Ti2O3 films with film thickness of ∼150 nm. The temperature dependence of resistivity indicated characteristic phase transitions. The insulator-to-metal transition (IMT) temperature (TIMT) deviated from bulk TIMT of ∼450 K. The higher and lower TIMTs of 450–600 K and 200–300 K were found in a- and c-axes oriented films, respectively. In addition, the large anisotropy in conductivity parallel and perpendicular to the c-axis direction was observed in the insulating phase, which was attributed to large difference in Hall mobility. The higher TIMT far above room temperature and the large difference in resistivity across the IMT were promising characteristics for application of Ti2O3 films in Mottronics.
Measurements of interlayer exchange coupling of Pt in Py|Pt|Py system
Authors: Omelchenko Pavlo , Heinrich Bret , Girt Erol
Published: October 2018

Ferromagnetic coupling strength through Pt is experimentally determined using ferromagnetic resonance studies of Py|Pt(dPt)|[Py|Fe] for Pt thicknesses, dPt, between 0.5 and 2.2 nm. The coupling strength decreases exponentially with the Pt thickness from 4.5 mJ/m2 for dPt = 0.5 nm and reduced to less than 0.02 mJ/m2 for dPt = 2.2 nm. The mechanism mediating exchange coupling is assumed to originate from the induced magnetization of Pt due to its proximity to ferromagnetic Py. The fitting thickness dependence of coupling with this model yields a characteristic coupling length scale of ξ = 0.31 ± 0.01 nm. Additionally, the molar susceptibility of proximity induced Pt is found to be 1.4 × 10−7 ± 0.2 × 10−7 m3/mol, an enhancement of ∼100 times as compared to bulk Pt. Ruderman-Kittel-Kasuya-Yosida type oscillations with a period of ∼0.8 nm are also observed as a small contribution of the total coupling.
The life and work of Elmer Samuel Imes
Authors: Mickens Ronald E.
Published: October 2018

Although the second African American to receive a physics PhD in the US faced obstacles because of his race, he blazed trails in spectroscopy and pedagogy.
Astrophysical high-energy neutrinos
Authors: Mészáros Peter
Published: October 2018

News from multiple messengers—neutrinos, cosmic rays, and photons—provides clues to the cosmic sources that create some of the most energetic particles observed on Earth.