bluuebunny/crossref_metadata_2025 huggingface dataset:
An Application of Generalized Moments Method to Examine the Management Behavior during Peak Season A Study in Islamic Micro Finance Industry
Authors: Nurhidayat Yayat
Published: October 2018

In the current highly competitive finance industry, it is important that any financial institution to develop a proper strategy to compete in the market. More specifically, the finance managers need to have an appropriate liquidity and stability strategy during the peak season where their customers have a high demand of cash. Finding such a strategy is challenging for micro finance institution due to their limited resources, in terms of finance and human resources. This study is aimed to (1) analyze the impact of liquidity risk to the stability of micro finance institutions and to (2) assess the relationship between liquidity risk and credit risk in the period of peak season by using Generalized Moments Method. The focus of this study is Islamic micro finance institutions in West Java for the period 2012-2017. Using monthly data, this study reveals that the risk of liquidity has a negative effect on the level of stability of micro finance institutions at peak season and has a positive influence on the level of stability at off peak season. Further, the study finds that the relationship between liquidity risk and credit risk is significant during the period of peak season and off peak season period. Therefore, it can be concluded that in general credit risk impacts on liquidity risk. The findings of this study provide significant contributions in terms of enlarging our understanding on the management behavior related to institution liquidity and stability during the peak and non-peak season. From managerial perspective, this study helps the Islamic micro finance institution to remain stable and competitive during the peak season.
Copper Electrodeposition onto Aluminum from a Copper Acid Baths In The Presence Of Poly Ethylene Glycol (PEG)
Authors: Budhi Susetyo Ferry , Situmorang Evi M.H. , Luthfiya Syifa , Soegijono Bambang
Published: October 2018

Many hydrophobic metal coatings onto Aluminum have been studied in recent years because of their significant potential applications. Unfortunately, most of them lost the original metallic luster due to the micro/nano binary structures. In this paper, a facile method was developed to prepare a hydrophobic and high-glossy copper coating onto aluminum substrates. The wettability and gloss could be tuned by the value of current density. With the increase of current deensity, the surface roughness raised, thus resulting in increase of contact angle and decrease of glossiness. When the current density was less than 1 mA/cm2, the coating exhibited good luster and prefered orientation. Lowering the Current density the coating showed different corrossion resistance and good water reppelence.
Konsens und Dissens im gemeinsamen Bestreben um Qualität
Authors: Singer Dominique
Published: October 2018

Liebe Leserinnen und Leser,

Schwangerschaft und Geburt als existentielle Erfahrungen im Leben einer Frau können nicht nur das meist antizipierte Gefühl von Glück und Vollendung oder die oft etwas unerwartete Neuordnung von Lebensplan und Partnerschaft nach sich ziehen, sie können sich in einzelnen Fällen auch psychisch traumatisierend auswirken.
Phytos im Aufwind: Der Medien-Hype und seine Folgen für die Phytotherapie
Authors: Brendieck-Worm Cäcilia
Published: October 2018

25 Jahre Phytotherapie-Weiterbildung Tiermedizin – ein Vierteljahrhundert! Seit den Anfängen hat sich viel geändert. Sprach man vor 25 Jahren kaum über pflanzliche Heilmittel, begegnet man heute täglich Anpreisungen von Heilpflanzen, sei es in Lebens- und Genussmitteln, in Tiernahrung, Pflegemitteln oder Kosmetika. Es ist ein regelrechter Heilpflanzen-Hype entstanden. Pflanzen werden zu Wunderdrogen. Derartige Tendenzen gab es schon sehr viel früher, z. B. beim Theriak.
Statine als Therapie bei Lebererkrankungen?
Authors: Sauerbruch Tilman , Schierwagen Robert , Trebicka Jonel
Published: October 2018

Statine vermindern die Cholesterinkonzentration im Plasma und senken damit das Risiko der koronaren Herzerkrankung. Darüber hinaus haben sie weitere sogenannte pleiotrope Effekte. Es gibt Hinweise, dass sich dies bei verschiedenen Lebererkrankungen positiv auswirken könnte.
Bimodal Hearing in Individuals with Severe-to-Profound Hearing Loss: Benefits, Challenges, and Management
Authors: Dunbar M. , Warren Sarah
Published: October 2018

Binaural hearing offers numerous advantages over monaural hearing. While bilateral implants are a successful treatment option for some patients, many individuals choose to achieve binaural hearing by using a cochlear implant with a contralateral hearing aid. Compared with monaural hearing, benefits of bimodal hearing include improved speech perception in quiet and in noise, improved localization, and more natural sound quality. Despite the advantages, there exist disadvantages to bimodal hearing, primarily related to binaural integration. Management of these devices can be challenging in that the hearing aid and cochlear implant may be managed by different clinicians. When fitting devices, strategies are recommended to optimize the integration of input from both devices. In managing bimodal devices, recommended outcomes measures include those that would reflect bimodal benefit, such as speech understanding in noise and spatial sound quality perception.
Fish Bone Foreign Body: The Role of Imaging
Authors: Klein Ayala , Ovnat-Tamir Sharon , Marom Tal , Gluck Ofer , Rabinovics Naomi , Shemesh Shay
Published: October 2018

Introduction Fish bone foreign body (FFB) impaction in the upper aerodigestive tract is a common cause for emergency department referral. Its management varies in both diagnosis and treatment paradigms. Fish bone foreign bodies are more commonly found in the oropharynx in cases of patients < 40 years old, and in the esophagus in cases of patients > 40 years old. Symptoms are typically non-indicative for the location of the FFB, with the exception of foreign body sensation at/superior to the cervical esophagus. A lack of findings during the physical examination is routinely followed by imaging, with computed tomography (CT) being the preferred modality. In practice, many patients undergo unnecessary imaging studies, including CT scans.

Objectives To identify patients with suspected fish bone impaction who do not require CT imaging and can be safely discharged.

Data Synthesis We have searched the PubMed database for the following medical subject headings (MeSH) terms: fish bone, fish foreign body AND oropharynx, hypopharynx, esophagus, flexible esophagoscopy, and rigid esophagoscopy. Our search in the English language yielded 32 papers. Case reports were included, since they highlighted rare and serious complications.

Conclusion In patients > 40 years old suspected of fish bone impaction, non-contrast CT is recommended and should be urgently performed, even in the presence of ambiguous symptoms. However, in patients < 40 years old presenting within 24 hours from ingestion, imaging has little diagnostic value due to the low probability of esophageal fish bones. For this specific subgroup, in the absence of clinical findings, discharge without imaging studies may be considered safe.
Do-It-Yourself Microsuture from Human Hair for Basic Microsurgical Training
Authors: Luangjarmekorn Pobe , Kitidumrongsook Pravit , Honsawek Sittisak
Published: October 2018

Background Microsuture is an essential material for basic microsurgical training. However, it is consumable, expensive, and sometimes unavailable in the microsurgical laboratory. To solve this problem, we developed a microsuture made from human hair and needle gauge.

Methods Do-It-Yourself (DIY) microsuture is made from human hair and needle gauge 32G (BD Ultra-Fine Pen Needles 4 mm × 32G). Methods are explained step by step. This DIY microsuture (labeled as “test microsuture”) and nylon 8–0 (Ethilon suture 8–0, labeled as “standard microsuture”) were used for teaching orthopaedic residents to perform arterial anastomosis in chicken thighs. All residents practiced without knowing that “test microsuture” was made from the DIY method. After completing the training, quality of both microsutures was evaluated by questionnaire in topics of (1) thread quality (size, strength, elasticity, handing, knot perform, and knot security), (2) needle quality (size, curve, shape, sharpness, handling, and strength), (3) needle–thread interface (size, strength, and smoothness), and (4) overall quality of microsuture. Each category was evaluated by Likert score (5 = excellent, 4 = good, 3 = fair, 2 = poor, and 1 = very poor).

Results The DIY microsuture was performed in three steps: (1) insert human hair into needle gauge by microforceps, (2) bend needle into smooth curve, and (3) disconnect needle and create needle–hair interface. The questionnaire was completed by 30 orthopaedic residents and showed that thread quality of DIY and standard microsuture had “good” and “good-to-excellent” quality (mean Likert score: 3.77–4.23 and 3.80–4.27, respectively, with no statistical difference). Thread–needle interface quality of DIY and standard microsuture also had “good” and “good-to-excellent” quality (Likert score: 3.73–4.20 and 4.07–4.33, respectively, with no statistical difference). Needle part of DIY microsuture had lower quality than standard suture (fair-to-good compared with good-to-excellence quality, score 3.30–3.67 vs. 4.20–4.27, respectively, with a statistically significant difference, p-value < 0.05). However, overall quality of DIY suture and standard microsuture had “good” and “good-to-excellent” (mean Likert score: 3.73 and 4.00, respectively, with no statistical difference).

Conclusion The DIY microsuture from human hair and needle gauge could be an alternative for basic microsurgical training with lower cost, easy production, and more availability for use in practice with acceptable quality compared with that of standard microsuture.
Asymptotic behavior and stability for the Schrödinger-Lohe model
Authors: Huh Hyungjin , Ha Seung-Yeal , Kim Dohyun
Published: October 2018

The Schrödinger-Lohe (S-L) model is an infinite-dimensional non-Abelian generalization of the Kuramoto model which serves as a prototype model for quantum synchronization. In this paper, we study asymptotic behavior and the nonlinear stability problem for the S-L model with identical (one-body) potential. For this model, we show that there are only two possible asymptotic states (the completely synchronized state or bi-polar state) emerging from generic initial data, and the completely synchronized state and bi-polar state are nonlinearly stable and unstable, respectively. The restricted uniform L2-stability is established with respect to constrained initial data on some invariant manifold. We also present the global existence and stability of standing wave solutions for the S-L model with a harmonic potential.
Optical vs electronic gap of hafnia by ab initio Bethe-Salpeter equation
Authors: Sklénard Benoît , Dragoni Alberto , Triozon François , Olevano Valerio
Published: October 2018

We present first-principles many-body perturbation theory calculations of the quasiparticle electronic structure and the optical response of HfO2 polymorphs. We use the GW approximation including core electrons by the projector augmented wave method and performing a quasiparticle self-consistency also on wavefunctions. In addition, we solve the Bethe-Salpeter equation on top of GW to calculate optical properties including excitonic effects. For monoclinic HfO2, we find a fundamental bandgap of Eg = 6.33 eV (with the direct bandgap at Egd=6.41 eV) and an exciton binding energy of 0.57 eV, which situates the optical gap at Ego=5.85 eV. The latter is in the range of spectroscopic ellipsometry (SE) experimental estimates (5.5–6 eV), whereas our electronic bandgap is well beyond experimental photoemission (PE) estimates (<6 eV) and previous GW works. Our calculated density of states and optical absorption spectra compare well to raw PE and SE spectra. This suggests that our predictions of both optical and electronic gaps are close to, or at least lower bounds of, the real values.
Quantum well capture and base carrier lifetime in light emitting transistor
Authors: Li Yue , Leburton Jean-Pierre
Published: October 2018

We carry out the physical modeling of the light emitting transistor (LET) operation with the focus on the carrier lifetime in the base, which is a key factor in the device speed performances. Our model is based on the observation of the degradation of the base transport factor caused by the LET heavy base doping and its variation with the base current. We revise the conventional charge control model of the bipolar junction transistor to account for these features and assess the concentration of the base minority carriers captured in the quantum wells (QWs). Our approach based on the Zhang and Leburton (Z-L) rate equation model enables us to obtain the device microscopic parameters, such as the capture time, the base lifetime and the base transit time in terms of the LET emitter current and the base current, as well as the design parameters such as the doping concentration, the base width, the QW width and number, and their location. Whereas the base recombination lifetime can be estimated to be of the order of a fraction of a nanosecond, the QW capture time is found to be of the order of a picosecond or less. Our simulation results agree well with the LET optical frequency response obtained experimentally.
Pressure of a viscous droplet squeezing through a short circular constriction: An analytical model
Authors: Zhang Zhifeng , Drapaca Corina , Gritsenko Dmitry , Xu Jie
Published: October 2018

The model of a droplet squeezed through a narrow-constricted channel has many applications in pathology, chip/filter/membrane design, drug delivery, etc. Understanding the transient physics of the squeezing process is important in the design and optimization of many micro flow systems. However, available models often ignore the influence of droplet viscosity, and they usually feature low numerical efficiency by solving Navier-Stokes equations. In the present research, we developed a low-dimension analytical model to predict the pressure of squeezing a viscous droplet through a circular constricted channel with acceptable fidelity and low computational cost. Our approach is as follows. We first adapt the Hagen–Poiseuille law to predict the viscosity effect of droplet squeezing. Next, we obtain an analytical expression for the extra pressure caused by only the curvature change obtained. Finally, the general expression of squeezing pressure taking consideration of viscosity and surface tension is expressed. The analytical model we developed is in great agreement with the numerical solutions of the Navier-Stokes equation at a low Reynolds number and low capillary number. These findings have fundamental significance for future applications in engineering and industry.
Defect evolution in ultralow energy, high dose helium implants of silicon performed at elevated temperatures
Authors: Haynes K. , Hu X. , Wirth B. D. , Hatem C. , Jones K. S.
Published: October 2018

There is a growing interest in using high dose helium implants to alter point defect populations in silicon. Previous reports have shown that the interaction between helium and vacancies leads to the formation of cavities for medium energy (e.g., 20–100 keV) implants. However, the role of certain factors, such as the proximity of the surface, the damage created by the implant, and the effect of the implant temperature, is not well understood for low energy implants. This study explored a new regime of ultralow energy, elevated temperature implants in order to offer an insight into the effect of these parameters. Transmission electron microscopy (TEM) showed that cavity formation was avoided for 0.5 keV, 450 °C implants up to a dose of 8 × 1016 cm−2. However, extended defects in the form of {311} ribbon-like defects and stacking faults were observed. Quantitative TEM showed that the number of interstitials in these defects was less than 0.2% of the implant dose. In addition, thermal helium desorption spectrometry suggested that only 2% of the implanted He dose was retained in interstitial He and HemVn complexes. A first-order dissociation kinetic model was applied to assess desorption from HemVn, which closely matched energies predicted by density functional theory. This population of excess vacancies and excess interstitials was possibly formed because of incomplete Frenkel pair recombination. Raman spectroscopy showed that the stress from the implant was dominated by the stress from the interstitial-type defects. The evolution of the stress and defects was also explored as a function of post-implant annealing.
A shade dispersion scheme using Latin square arrangement to enhance power production in solar photovoltaic array under partial shading conditions
Authors: Madhusudanan Gurusamy , Senthilkumar Subramaniam , Anand I. , Sanjeevikumar Padmanaban
Published: October 2018

Partial shading in a solar array deteriorates the maximum power generated owing to the voltage mismatch and current mismatch of the shaded solar PV module. Also, partial shading primes to multiple peaks in the P-V characteristics of the solar PV array and it has become more complex to track the Maximum Power Point (MPP). To enhance the maximum power generated by means of reducing mismatch losses, several reconfiguration techniques were suggested earlier. The mismatch losses depend not only on the amount of the area shaded but also on the shading pattern and array arrangement. This paper proposes a new pattern of positioning the PV module using the Latin square pattern without changing the total cross tied electrical connection. The proposed pattern disperses the shading uniformly within the given PV array which reduces mismatch losses significantly and increases the generation of power. The shade dispersion using proposed pattern also eliminates multiple peaks in its PV curve which enables the use of a simple algorithm to track MPP. This Latin square pattern is studied under different partial shading conditions, and the results exhibit improved performance under partial shading conditions.
Bandlike and localized states of extended defects in n-type In0.53Ga0.47As
Authors: Hsu Po-Chun (Brent) , Simoen Eddy , Merckling Clement , Eneman Geert , Mols Yves , Alian AliReza , Langer Robert , Collaert Nadine , Heyns Marc
Published: October 2018

In0.53Ga0.47As p + n diodes with different densities of extended defects have been analyzed by detailed structural and electrical characterization. The defects have been introduced during Metal-Organic Vapor Phase Epitaxy (MOVPE) growth by using a lattice-mismatched layer on a semi-insulating InP or GaAs substrate. The residual strain and indium content in the n-type In0.53Ga0.47As layer have been determined by high-resolution X-ray diffraction, showing nearly zero strain and a fixed indium ratio of 0.53. The deep levels in the layer have been characterized by Deep Level Transient Spectroscopy. The mean value of electron traps at 0.17 ± 0.03 eV below the conduction band minimum EC is assigned to the “localized” states of α 60° misfit dislocations; another broad electron trap with mean activation energies between EC− 0.17 ± 0.01 and 0.39 ± 0.04 eV, is identified as threading dislocation segments with “band-like” states. A high variation of the pre-exponential factor KT by 7 orders of magnitude is found for the latter when changing the filling pulse time, which can be explained by the coexistence of acceptor-like and donor-like states in the core of split dislocations in III-V materials. Furthermore, two hole traps at EV+ 0.42 ± 0.01 and EV+ 0.26 ± 0.13 eV are related to the double acceptor of the Ga(In) vacancy (VGa/In3-/2-) and 60° β misfit dislocations, respectively. Finally, the dislocation climbing mechanism and the evolution of the antisite defects AsGa/In are discussed for n-type In0.53Ga0.47As.
Transverse resonance island buckets for synchrotron-radiation based electron time-of-flight spectroscopy
Authors: Arion T. , Eberhardt W. , Feikes J. , Gottwald A. , Goslawski P. , Hoehl A. , Kaser H. , Kolbe M. , Li J. , Lupulescu C. , Richter M. , Ries M. , Roth F. , Ruprecht M. , Tydecks T. , Wüstefeld G.
Published: October 2018

At the Metrology Light Source (MLS), the compact electron storage ring of the Physikalisch-Technische Bundesanstalt (PTB) with a circumference of 48 m, a specific operation mode with two stable closed orbits for stored electrons was realized by transverse resonance island buckets. One of these orbits is closing only after three turns. In combination with single-bunch operation, the new mode was applied for electron time-of-flight spectroscopy with an interval of the synchrotron radiation pulses which is three times the revolution period at the MLS of 160 ns. The achievement is of significant importance for PTB’s future programs of angular-resolved electron spectroscopy with synchrotron radiation and similar projects at other compact electron storage rings. The scheme applied here for selecting the photons originating from a particular orbit by optical imaging has been used before in fs slicing applications and may be relevant for the BESSY VSR project of the Helmholtz-Zentrum Berlin.
Ferromagnetic resonance manipulation by electric fields in Ni81Fe19/Bi3.15Nd0.85Ti2.99Mn0.01O12 multiferroic heterostructures
Authors: Xiong Rongxin , Zhang Wanli , Fang Bin , Li Gang , Li Zheng , Zeng Zhongming , Tang Minghua
Published: October 2018

We investigated electric-field modulation of ferromagnetic resonance (FMR) in Ni81Fe19 (NiFe)/Bi3.15Nd0.85Ti2.99Mn0.01O12 (BNTM) heterostructures at room temperature. BNTM thin films were deposited on a Pt (111)/Ti/SiO2/Si (100) substrate by the sol-gel method. The strain effect is produced by the electric field applied to the BNTM layer, which results in the FMR spectrum shift by tuning of the magnetic anisotropy of the NiFe microstrip devices. A strain-induced magnetic anisotropy change of 332 fJ/Vm is obtained by analyzing the experimental FMR spectra. We discussed an influence on spin orbit torques by applying an electric field to a ferroelectric (FE) layer via coupling to polarization with FMR experiments evidencing. The torque ratios τa/τb increased at first and then declined from the positive to negative electric field. As the value of the applied electric field changes from 129 kV/cm to 0 kV/cm, the variation of the torque ratios τa/τb (the field-like torque τa and damping-like torque τb) is about 0.07. Our results reported in this work demonstrate a route to realize a large magneto-electric coupling effect at room temperature and provide some insights into possible applications of the ferromagnetic/FE device.
Behaviour of charge carriers in thermally reduced graphene oxide: Magnetism and ambipolar transport
Authors: Kempiński Mateusz , Łoś Szymon , Florczak Patryk , Kempiński Wojciech
Published: October 2018

We report a research study on reduced graphene oxide conducted with electron paramagnetic resonance and impedance spectroscopy techniques. Coupling of the two experimental methods allowed us to obtain detailed information on the charge carrier transport in the graphene material and make an attempt at explaining the peculiar behaviour of para- and ferromagnetic properties of the studied system. Two scattering processes characterized by different dynamics were found. An ambipolar-like character of the charge transport was observed with transition between holes and electrons driven by the bias voltage, temperature, and adsorption. Electron paramagnetic resonance spectra showed a typical signal from localized centers as well as weak ferromagnetism. The latter correlates with the change of carriers' polarity. This indicates that ferromagnetic coupling between the localized states in graphene is related to the type of charge carriers. Such behavior points to the similarity of reduced graphene oxide to the dilute (ferro)magnetic semiconductors.
Inverse-direct magnetocaloric effect crossover in Ni47Mn40Sn12.5Cu0.5 Heusler alloy in cyclic magnetic fields
Authors: Gamzatov A. G. , Aliev A. M. , Ghotbi Varzaneh A. , Kameli P. , Abdolhosseini Sarsari I. , Yu S. C.
Published: October 2018

The results of direct studies of the magnetocaloric effect (MCE) of the Ni47Mn40Sn12.5Cu0.5 Heusler alloy in cyclic magnetic fields are presented. It is shown that in cyclic magnetic fields, the MCE value near the magnetostructural phase transition depends on the rate of temperature scanning. A higher rate of change in the sample temperature causes the MCE to have a greater value. The observed effect is explained by irreversible phase transition, induced by a magnetic field, from a low-symmetry martensitic phase to a high-symmetry austenitic phase. Moreover, it is observed only within the temperature hysteresis loop of the magnetostructural phase transition. Such materials, despite the considerable MCE values under a single application of the magnetic field, are unpromising due to a strong change in the magnetocaloric properties in cyclic magnetic fields.
Influence of solar wind structure on cosmic ray modulation during epochs of alternate solar magnetic polarity
Authors: Oh Suyeon , Yi Yu , Evenson Paul
Published: October 2018

The cosmic ray flux is anti-correlated with the sunspot number such that the flux maximum occurs approximately at solar minimum. Different time profiles of the cosmic ray maxima are probably related to the solar magnetic polarity influence on the balance between drift and diffusion. This study examines the differences in the flux variation of cosmic ray particles at epochs of alternate solar magnetic polarity by applying period analysis, specifically focusing on the period of solar rotation. We examine cosmic ray data from 43 neutron monitors at solar minimum years since 1954. We find that the periodicity at 27 days is stronger in positive than in negative magnetic epochs except for 2008 when it is stronger in northern neutron monitors (but not southern monitors). The yearly variation of power at 27 days shows peaks at the solar minimum years in the positive polarity, except for 2008 in the northern neutron monitors. It also shows an increase near solar maximum. Power at 22 years of the yearly variation of power at 27 days shows an increasing trend at middle-latitude northern and southern neutron monitors. Different effects of drift and diffusion could explain the different periodicity at 27 days in solar minimum years of both solar magnetic polarities and the shapes of cosmic ray flux maximum. The influence of details of the solar wind structure on cosmic ray fluxes can explain the periodicity of cosmic ray particles at the solar rotation period. The degree of this influence is clearly different during epochs of differing magnetic polarity. The most probable explanation for this is the solar polarity dependence of the cosmic ray latitude gradient.
Preparation and physical properties of soft magnetic nickel-cobalt three-segmented nanowires
Authors: Bochmann Sebastian , Döhler Dirk , Trapp Beatrix , Staňo Michal , Fruchart Olivier , Bachmann Julien
Published: October 2018

We review a method to produce cylindrical magnetic nanowires displaying several segments, with a large versatility in terms of segment diameter and length. It is based on electroplating in alumina templates, the latter being prepared by several steps of anodization, wet etching, and atomic layer deposition to produce, widen, or shrink pores, respectively. We propose an analytical model to analyze the in-plane and out-of-plane magnetization loops of dense assemblies of multisegmented wires. The model considers inter-wires dipolar fields and end-domain curling and predicts the switching field of individual wires with no adjustable parameter. Its ingredients are crucial to extract reliable parameters from the fitting of loops, such as magnetization or the porosity of the array.
Interaction of planar shock wave with three-dimensional heavy cylindrical bubble
Authors: Ding Juchun , Liang Yu , Chen Mojun , Zhai Zhigang , Si Ting , Luo Xisheng
Published: October 2018

Interactions of a planar shock wave with two-dimensional (2D), three-dimensional (3D) concave, and 3D convex SF6 cylindrical bubbles surrounded by air are studied both experimentally and numerically. The effects of initial interface curvature on the bubble deformation and wave propagation are highlighted. The cylindrical bubbles are generated by a wire-restriction method based on the soap-film technique, and their shapes are well controlled by adjusting the pressure difference across the interface. The high-speed schlieren results demonstrate that the evolving interfaces develop more symmetrically than previous studies as they are free of holder and fewer disturbance waves are generated. Typical evolution processes of the 2D bubble such as the jet formation and vortex pair formation are clearly captured. Compared with the 2D case, the oppositely (identically) signed principal curvatures of the concave (convex) boundary produce more complicated high pressure fields and 3D additional baroclinic vorticity. For 3D cases, the numerical results show that the wave patterns in the symmetry or boundary slice are distinct from the 2D case owing to the 3D movement of the generated waves, and the jet structure presents an evident three dimensionality. In particular, for the concave bubble, a certain slice between the boundary and symmetry slices presents the fastest-developing jet, while for the convex case the fastest jet emerges at the boundary slice. The upstream interface along the symmetry slice of the concave (convex) bubble moves faster (slower) than that of the 2D case, which is reasonably predicted by a 3D theoretical model.
On the performance of DFT/MRCI Hamiltonians for electronic excitations in transition metal complexes: The role of the damping function
Authors: Heil Adrian , Kleinschmidt Martin , Marian Christel M.
Published: October 2018

The combination of density functional theory and multireference configuration interaction (DFT/MRCI) is a well-established semi-empirical method suitable for computing spectral properties of large molecular systems. To this day, three different Hamiltonians and various parameter set combinations exist. These DFT/MRCI variants are well tried and tested when it comes to electronic excitations of organic molecules. For transition metal complexes, systematic benchmarks against experimental data are missing, however. Here we present an assessment of the DFT/MRCI variants and of time-dependent, linear-response density functional theory (TDDFT) for a diverse set of ligand-centered, metal-to-ligand charge transfer, metal-centered, and ligand-to-metal charge transfer (LMCT) excitations on 21 3d and 4d complexes comprising 10 small inorganic and 11 larger metalorganic compounds with closed-shell ground states. In the course of this assessment, we realized that the excitation energies of transition metal complexes can be very sensitive with respect to the details of the damping function that scales off-diagonal matrix elements. This scaling is required in DFT/MRCI to avoid double counting of dynamic electron correlation. These insights lead to a new Hamiltonian, denoted R2018, with improved performance on transition metal compounds, while the results for organic molecules are nearly unaffected by the modified damping function. Two parameter sets were optimized for this Hamiltonian: One set is to be used in conjunction with the standard configuration selection threshold of 1.0 Eh and a second set is for use with a selection threshold of 0.8 Eh which leads to shorter wave function expansions. The R2018 Hamiltonian in standard parameterization achieves root-mean-square errors (RMSEs) of merely 0.15 eV for the metalorganic complexes, followed by 0.20 eV for the original DFT/MRCI ansatz, and 0.25 eV for the redesigned DFT/MRCI approach. In comparison, TDDFT gives a much larger RMSE of 0.46 eV for metalorganic complexes. None of the DFT/MRCI variants yields convincing results for small oxides and fluorides which exhibit LMCT transitions. Here, TDDFT performs better. If the oxides and fluorides are excluded from the inorganic test set, satisfactory agreement can be achieved, with RMSE values between 0.26 eV and 0.30 eV for DFT/MRCI and 0.34 eV for TDDFT. The performance of the original and the new DFT/MRCI Hamiltonians deteriorates only slightly, when a tighter selection threshold is chosen, thus enabling the computation of reliable spectral properties even for large metalorganic complexes.
Tailoring dielectric properties and multiferroic behavior of nanocrystalline BiFeO3 via Ni doping
Authors: Nadeem M. , Khan Wasi , Khan Shakeel , Husain Shahid , Ansari Azizurrahaman
Published: October 2018

In order to tailor the multiferroic as well as dielectric properties, we have synthesized BiFeO3 (BFO) and Ni-doped BFO nanoparticles of composition BiFe1-xNixO3 (0 ≤ x ≤ 0.07) via the sol-gel method. The influence of Ni-doping at the Fe site of BiFeO3 on the structural, dielectric, and multiferroic properties was investigated via various characterization techniques such as Raman spectroscopy, vibrating sample magnetometer, polarization-electric field (P-E) loop tracer, and LCR meter. The Raman spectra reveal the rhombohedral distorted perovskite structure of the samples in the R3c space group. The frequency dependent dielectric measurements at room temperature show that the dielectric constant for the pristine sample is an order of magnitude lower than the 1% Ni-doped BFO sample. It is also evident that the ac conductivity increases with the increase in frequency as well as Ni content. Further, the universal dielectric response (UDR) phenomenon is responsible for the dielectric behavior of all the samples in the whole frequency range except for the BiFeO3 and BiFe0.97Ni0.03O3 samples. These samples exhibit deviation from UDR phenomenon at higher frequencies. The room temperature hysteresis (M-H) loops exhibit the saturation in magnetization at higher magnetic fields. The result demonstrates a significant influence on the saturation magnetization with the Ni doping in BFO, prompting the ferromagnetic nature of the samples. The saturation magnetization of the 7% Ni-doped sample is approximately six times higher than the pristine one. The saturated P-E hysteresis loops establish the ferroelectric nature of the synthesized samples that are enhanced significantly on Ni doping. Thus, the doping of Ni in BiFeO3 improves the multiferroic properties of the matrix.
Broadband coherent perfect absorption of acoustic waves with bubble metascreens
Authors: Lanoy Maxime , Guillermic Reine-Marie , Strybulevych Anatoliy , Page John H.
Published: October 2018

A bubble metascreen is an exceptionally effective and low frequency resonator which can be optimized in order to exactly balance the energy provided by radiative process and lost under a viscous mechanism (critical coupling). Under this condition, one can absorb 99.9% of the energy carried by two phase-matched counter-propagating acoustic beams. This phenomenon, called coherent perfect absorption, is here observed with bubbles 75 times smaller than the incident wavelength and is shown to be remarkably broadband. Finally, tuning the relative phases of the two beams turns out to be an efficient way to control the absorption in the medium.
An experimental study of a-Si/ZnO-stacked hetero-structures for potential thermoelectric energy harvesting applications
Authors: Ha Jaekwon , Jeon Buil , Yoon Chongsei , Yoon Giwan
Published: October 2018

Here, we present a study of thermoelectric devices with amorphous silicon/zinc oxide (a-Si/ZnO)-stacked hetero-structures fabricated using both radio frequency magnetron sputtering and rapid thermal annealing techniques. Overall, the Seebeck coefficient (S) and power factor (S2σ, where σ is the electrical conductivity) of the a-Si/ZnO-stacked hetero-structures were found to be superior to those of pure a-Si structures. In particular, the Seebeck coefficient and power factor of the a-Si/ZnO (9/8 layers)-stacked hetero-structures were about 1.6 and 23.8 times those of the pure a-Si structures, respectively. These improvements can be attributed to hole blocking by the a-Si/ZnO potential barriers formed at the interface between the ZnO layer with a wide energy bandgap and the a-Si layer with a relatively narrow bandgap. In addition, the a-Si and ZnO materials used in this work are non-toxic, earth-abundant, and cheap, and the fabrication processes were simple and cost-effective, making the hetero-structures suitable for use in non-toxic and biocompatible thermoelectric devices and also for micro-energy harvesting applications.
Generation of rogue waves in space dusty plasmas
Authors: Rahman M. H. , Mannan A. , Chowdhury N. A. , Mamun A. A.
Published: October 2018

The basic features of dust-acoustic (DA) waves (DAWs) in a four component dusty plasma system (containing inertial cold and hot dust grains and inertialess non-extensive ions and electrons) have been theoretically investigated by deriving the nonlinear Schrödinger equation. The analytic analysis under consideration demonstrates two types of modes, namely, fast and slow DA modes. The unstable domain, which can be recognized by the critical wave number (kc), gives rise to the DA rogue waves (DARWs). It is observed that the amplitude and width of the DARWs are significantly modified by various plasma parameters. The present results should be useful in understanding the conditions for modulational instability of DAWs and generation of DARWs in Saturn F-rings.
Demystifying the growth of superconducting Sr2RuO4 thin films
Authors: Nair Hari P. , Ruf Jacob P. , Schreiber Nathaniel J. , Miao Ludi , Grandon Morgan L. , Baek David J. , Goodge Berit H. , Ruff Jacob P. C. , Kourkoutis Lena F. , Shen Kyle M. , Schlom Darrell G.
Published: October 2018

We report the growth of superconducting Sr2RuO4 thin films by molecular-beam epitaxy on (110) NdGaO3 substrates with transition temperatures of up to 1.8 K. We calculate and experimentally validate a thermodynamic growth window for the adsorption-controlled growth of superconducting Sr2RuO4 epitaxial thin films. The growth window for achieving superconducting Sr2RuO4 thin films is narrow in growth temperature, oxidant pressure, and ruthenium-to-strontium flux ratio.
Determination of modified figure of merit validity for thermoelectric thin films with heat transfer model: Case of CuCrO2:Mg deposited on fused silica
Authors: Sinnarasa Inthuga , Thimont Yohann , Presmanes Lionel , Barnabé Antoine , Tailhades Philippe
Published: October 2018

Thermoelectric performance of a material is determined using a figure of merit (FOM) determined as ZT (ZT = σS2T/κ where σ is the electrical conductivity, S is the Seebeck coefficient, κ is the thermal conductivity, and T is the temperature). In the case of a thin film, it is normal in the first approach to consider calculating the FOM by using the thermal conductivity of the film. However, both the thermal influence of the substrate and the emissivity of the film must also be taken into account. In the present work, the heat transfer model is used in order to study the influence of the thermal conductivity, the thickness, and the emissivity of the film on the thermal gradient of the stack (substrate + thin film). The limits of these three parameters are determined in order to have the temperature variation due to the presence of the film compared to the substrate alone that remains less than 1%. Under these limits, the thermal conductivity of the substrate can be taken into account instead of the thermal conductivity of the thin film, and a modified FOM (Z’T) can be calculated. The present study leads to the determination of the validity of modified ZT. In the case of CuCrO2:Mg thin films, the model shows that the use of Z’T is valid. The calculated value of Z’T with the measured Seebeck coefficient and the electrical conductivity as a function of the temperature for 100 nm thick films and the temperature dependent thermal conductivity taken from the literature reached 0.02 at 210 °C. A thermoelectric module made with this material showed 10.6 nW when 220 °C is applied at the hot side.
Multiscale local porosity theory, weak limits, and dielectric response in composite and porous media
Authors: Hilfer R.
Published: October 2018

A mathematical scaling approach to macroscopic heterogeneity of composite and porous media is introduced. It is based on weak limits of uniformly bounded measurable functions. The limiting local porosity distributions that were introduced in the work [Adv. Chem. Phys. XCII, 299–424 (1996)] are found to be related to Young measures of a weakly convergent sequence of local volume fractions. The Young measures determine frequency dependent complex dielectric functions of multiscale media within a generalized self-consistent effective medium approximation. The approach separates scales by scale factor functions of regular variation. It renders upscaled results independent of the shape of averaging windows upon reaching the scaling limit.
Single-molecule force spectroscopy reveals folding steps associated with hormone binding and activation of the glucocorticoid receptor
Authors: Suren Thomas , Rutz Daniel , Mößmer Patrick , Merkel Ulrich , Buchner Johannes , Rief Matthias
Published: October 2018

Significance

The glucocorticoid receptor (GR) is an important signaling protein and a prominent drug target. Cortisone, one of the drugs directed against the GR, is among the most prescribed drugs worldwide. Hormone binding leads to activation of the receptor, which is then transported into the nucleus, affecting gene transcription. Despite its importance, little is known about the structural prerequisites of hormone binding and the associated conformational changes. We used a mechanical single-molecule method that allowed us to observe in detail the steps of folding and hormone binding of GR. We identify a structural element that opens and closes upon hormone binding. Our results form the basis for understanding GR activation and its regulation by chaperone proteins.
Structural consequences of hereditary spastic paraplegia disease-related mutations in kinesin
Authors: Dutta Mandira , Diehl Michael R. , Onuchic José N. , Jana Biman
Published: October 2018

Significance

Motor proteins are important biological machines responsible for cellular transport. Malfunctioning of them causes several neurodegenerative diseases. We searched for a molecular-level answer for malfunctioning kinesin, which causes hereditary spastic paraplegia (HSP) disease. Using explicit solvent simulation, the thermodynamic integration (TI) method, and bioinformatics analysis, we explored how four HSP mutants of kinesin perturb microtubule (MT) binding and motor dimerization. Taking these observations into account, we developed a coarse-grained structure-based model to reveal the effect of these mutations on kinesin’s order–disorder transition, which leads to the processivity and directionality of kinesin. Our study potentially uncovers a molecular-level picture of the role of some HSP mutants and its broad aspect in kinesin mechanochemistry.
The stiffness response of type IIa fibres after eccentric exercise‐induced muscle damage is dependent on ACTN3 r577X polymorphism
Authors: Broos Siacia , Malisoux Laurent , Theisen Daniel , Van Thienen Ruud , Francaux Marc , Thomis Martine A. , Deldicque Louise
Published: October 2018

The aim of the study was to determine the effect of α‐actinin‐3 (ACTN3) deficiency (XX) on muscle damage induced by an eccentric exercise bout. In this purpose, 4 RR and 4 XX individuals performed an intensive eccentric knee flexion exercise on an isokinetic dynamometer. Muscle biopsies, blood and pain scores were taken before and after the exercise to determine the extent of the exercise‐induced damage and the effect of the ACTN3 R577X polymorphism. Maximal isometric strength of the quadriceps and single fibre properties were compared before and after the exercise. The drop in maximal isometric strength of the quadriceps at 45° knee flexion following the eccentric exercise bout was on average 37% 24 h post‐exercise. The decrease in force was also apparent in isolated type IIa fibres (8%; P = 0.02), but not in type I fibres (P = 0.88). Creatine kinase and myoglobin plasma levels increased in all participants at least by 55% and 87%, respectively (P < 0.05). In addition, mRNA levels of markers for muscle regeneration and muscle remodelling increased after the eccentric exercise (P < 0.05), however, independently from ACTN3 R577X genotype. The mRNA level of nuclear factor of activated T‐cells 1 (NFATc1) decreased after the eccentric exercise only in XX genotypes (P < 0.05). The stiffness of type IIa, but not type I muscle fibres increased only in RR individuals after the eccentric exercise (P < 0.05). While no major effect of α‐actinin‐3 deficiency on susceptibility to muscle damage was found acutely, the increased stiffness response in fast RR fibres might be a protection mechanism from muscle damage during a subsequent eccentric exercise bout.
The influence of hip mobility and quadriceps fatigue on sagittal spinal posture and muscle activation in rugby scrum performance
Authors: Clayton Joshua D. , Kirkwood Renata N. , Gregory Diane E.
Published: October 2018

Rugby Union scrumming puts the spine under a high degree of loading. The aim of the current study was to determine how sagittal hip range of motion and quadriceps fatigue influence force output, spinal posture, and activation of the trunk and quadriceps muscles in rugby scrumming. Measures of sagittal hip flexion/extension range of motion were collected from 16 male varsity and club first XV level participants. Sagittal spine motion (electromagnetic motion capture), trunk and quadriceps activation (electromyography), and applied horizontal compressive force (force plate) were measured during individual machine scrumming. Participants performed a 5‐trial scrum block involving 5 s of contact with 1–2 min recovery between each trial. They then performed a fatiguing protocol (wall sit to failure) and immediately returned to the scrum machine to perform another five trials. Though there was no significant influence of fatigue on the horizontal compressive force applied during contact (P = .83), there was a 52% increase in cervical flexion (P < .001), as well as decreased (18–23% lower) abdominal and erector spinae muscle activation (P < .05). Furthermore, quadriceps activation decreased (12–25% lower) over the course of the initial scrum block but increased (13–15% higher) in the post fatigue block (P < .05). Although athletes were able to maintain force output following the fatiguing wall sit task, there is the potential that they may be at an increased risk of spinal injury due to the combination of increased flexion and high‐applied compressive force; a combination which has been shown to increase the likelihood of intervertebral disc herniation.