bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiac screening of intact Drosophila melanogaster larvae under exposure to aqueous and gaseous toxins in a microfluidic device
Authors: Ardeshiri R. , Hosseini L. , Amini N. , Rezai P.
Published: July 2016

We present a semi-automated microfluidic chip for orientation, immobilization, chemical exposure, and cardiac screening of 3rd instar Drosophila melanogaster larvae.
Work function engineering derived all-solid-state Z-scheme semiconductor-metal-semiconductor system towards high-efficiency photocatalytic H2 evolution
Authors: Li Shuo , Zhao Qidong , Wang Dejun , Xie Tengfeng
Published: July 2016

The work function engineering of the intermediate metal plays a key role in Z-scheme photosynthetic systems.
Continuous flow synthesis concatenated with continuous flow liquid–liquid extraction for work-up and purification: selective mono- and di-iodination of the imidazole backbone
Authors: Drageset Audun , Bjørsvik Hans-René
Published: July 2016

Flow processes for mono- and di-iodination of the imidazole backbone were devised, developed, and implemented on the multi-jet oscillating disk (MJOD) flow reactor platform.
Simple hydrothermal synthesis of very-long and thin silver nanowires and their application in high quality transparent electrodes
Authors: Bari Bushra , Lee Jinhwan , Jang Taehee , Won Phillip , Ko Seung Hwan , Alamgir Khalid , Arshad Muhammad , Guo L. Jay
Published: July 2016

Well dispersed very long and thin silver nanowires are synthesized using glucose as a reducing agent and silver chloride as a silver source. The wire lengths are in the range of 200 to 500 microns with an average diameter of 45–65 nm.
A highly active cocatalyst-free semiconductor photocatalyst for visible-light-driven hydrogen evolution: synergistic effect of surface defects and spatial bandgap engineering
Authors: Yu Guiyang , Zhang Wenxiang , Sun Yanjun , Xie Tengfeng , Ren Ai-Min , Zhou Xin , Liu Gang
Published: July 2016

A synergistic strategy of spatial bandgap engineering and surface defect is efficient to construct a highly active semiconductor photocatalyst.
Surfactant-free HEMA crystal colloidal paint for structural color contact lens
Authors: Liu Panmiao , Xie Zhuoying , Zheng Fuyin , Zhao Yuanjin , Gu Zhongze
Published: July 2016

A new type of structural color paint was fabricated by dispersing poly(methyl methacrylate-hydroxyethyl methacrylate) (PMH) nanoparticles in 2-hydroxyethyl methacrylate (HEMA) solvent without additional surfactants. The paints then were directly cast to form structural color contact lenses by UV polymerization in moulds.
The dual-model up/down-conversion green luminescence of Gd6O5F8:Yb3+,Ho3+,Li+ and its application for temperature sensing
Authors: Du Shanshan , Wang Deyin , Qiang Qinping , Ma Xinlong , Tang Zuobin , Wang Yuhua
Published: July 2016

Micro-sized Gd6O5F8 particles doped with Yb3+, Ho3+ and Li+ ions have been synthesized by a facile hydrothermal route.
Epigenetics changes caused by the fusion of human embryonic stem cell and ovarian cancer cells
Authors: He Ke , Qu Hu , Xu Li-Nan , Gao Jun , Cheng Fu-Yi , Xiang Peng , Zhou Can-Quan
Published: July 2016

To observe the effect of gene expression and tumorigenicity in hybrid cells of human embryonic stem cells (hESCs) and ovarian cancer cells in vitro and in vivo using a mouse model, and to determine its feasibility in reprogramming tumour cells growth and apoptosis, for a potential exploration of the role of hESCs and tumour cells fusion in the management of ovarian cancer. Stable transgenic hESCs (H1) and ovarian cancer cell line OVCAR-3 were established before fusion, and cell fusion system was established to analyse the related indicators. PTEN expression in HO-H1 cells was higher than those in the parental stem cells and lower than those in parental tumour cells; the growth of OV-H1 (RFP+GFP) hybrid cells with double fluorescence expressions were obviously slower than that of human embryonic stem cells and OVCAR-3 ovarian cancer cells. The apoptosis signal of the OV-H1 hybrid cells was significantly higher than that of the hESCs and OVCAR-3 ovarian cancer cells. In vivo results showed that compared with 7 days, 28 days and 35 days after inoculation of OV-H1 hybrid cells; also, apoptotic cell detection indicated that much stronger apoptotic signal was found in OV-H1 hybrid cells inoculated mouse. The hESCs can inhibit the growth of OVCAR-3 cells in vitro by suppressing p53 and PTEN expression to suppress the growth of tumour that may be achieved by inducing apoptosis of OVCAR-3 cells. The change of epigenetics after fusion of ovarian cancer cells and hESCs may become a novel direction for treatment of ovarian cancer.
Use of Language Sample Analysis by School-Based SLPs: Results of a Nationwide Survey
Authors: Pavelko Stacey L. , Owens Robert E. , Ireland Marie , Hahs-Vaughn Debbie L.
Published: July 2016

Purpose

This article examines use of language sample analysis (LSA) by school-based speech-language pathologists (SLPs), including characteristics of language samples, methods of transcription and analysis, barriers to LSA use, and factors affecting LSA use, such as American Speech-Language-Hearing Association certification, number of years' experience, and caseload characteristics.

Method

School-based SLPs responded to an invitation to complete an electronic survey related to LSA.

Results

One third of respondents indicated they did not use LSA during the 2012–2013 school year. SLPs who served middle and high school students were less likely to use LSA. Most respondents reported using conversation to analyze fewer than 10 samples and transcribing in real time. Additional analyses revealed that SLPs who had 3 or fewer years of experience and who analyzed fewer than 20 language samples per year were statistically less likely to report using real-time transcription. The most frequently cited barrier to using LSA was “LSA is too time-consuming.”

Conclusion

Many school-based SLPs do not routinely use LSA. Further, many did not report engaging in evidence-based practices, such as recording samples, using established protocols, or using tasks designed to elicit complex syntax. These results indicate a continued need for professional development regarding evidenced-based practices relative to LSA use.
My Bermuda Triangle
Authors: Fountain Vic Cobb
Published: July 2016

Vic Cobb Fountain recovered from a ruptured aneurysm with the help of her SLPs.
From My Perspective: We All Can Help Prevent Noise-Induced Hearing Loss
Authors: Themann Christa
Published: July 2016

Follow these easy steps—incorporated into your everyday practice—to help clients and patients adopt safe hearing practices.
From My Perspective: Toward Comprehensive Medicare Audiology Coverage
Authors: Eiten Leisha
Published: July 2016

Audiology organizations want Medicare to expand audiology coverage, but they disagree on how. Here's why the Medicare Audiology Services Enhancement Act of 2013 deserves your support.
The Best-Laid Plans
Authors: Randolph Mary
Published: July 2016

When an SLP’s vision of retirement gets waylaid by reality, her training and experience naturally kick in.
Welcome to a New Era
Authors: Dunham Gary
Published: July 2016

More useful than ever, afire in purpose, bold in look and synergized with social media, the new Leader wants to share more of your 150,000 lives, careers and stories than ever before.
In the Limelight: Family Matters
Authors: Rowden-Racette Kellie
Published: July 2016

They may be nine years apart, but by choosing the same profession, these sisters enjoy close ties.
In the Limelight: Mastering the Moguls
Authors: Rowden-Racette Kellie
Published: July 2016

Just like she handles the bumps on the slopes, SLP Katie Willard helps her clients navigate the ins and outs of social communication.
Two phase flow of liquids in a narrow gap: Phase interference and hysteresis
Authors: Raza Salim , Hejazi S. Hossein , Gates Ian D.
Published: July 2016

Co-current flow of two immiscible liquids, such as oil and water in a planar fracture, exhibits nonlinear structures which become important in many natural and engineering systems such as subsurface flows, multiphase flows in lubrication joints, and coating flows. In this context, co-current flow of oil and water with variable rates is experimentally studied in a Hele-Shaw cell, various flow regimes are classified, and relative permeabilities for the phases are analysed thoroughly. Similar to multiphase pipe flows, multiphase flow in planar gaps shows various flow regimes, each having different flow rate/pressure gradient behaviour. As well as recovering the known results in the immiscible displacements in Hele-Shaw cell where the fluid-fluid interface remains stable/unstable for favorable/adverse viscosity ratios, it is found that the co-current flow of two fluids with different viscosities results in three distinct flow regimes. Before breakthrough of non-wetting phase, i.e, water, a “linear displacement” flow regime initially establishes at very low water injection rates. This stable movement turns into a “fingering advancement” flow regime at high water flow rates and Saffman-Taylor instability develops normal to the direction of the flow. After the breakthrough, a “droplet formation” flow regime is identified where the droplets of wetting phase, oil, are trapped in the water phase. For subsurface flow applications, we quantify these regimes through relative permeability curves. It is reported that as the water flow rate increases, the relative permeabilities and flow channels become smooth and regular. This behaviour of relative permeability and saturations shows dominance of capillary forces at low flow rates and viscous forces at higher flow rates. Variable injection rates provide the interface structures for both drainage and imbibition process, where the wetting phase saturation decreases and increases respectively. It is shown that relative permeability curves exhibit hysteresis, thus the process is irreversible.
Gigahertz single-electron pumping in silicon with an accuracy better than 9.2 parts in 107
Authors: Yamahata Gento , Giblin Stephen P. , Kataoka Masaya , Karasawa Takeshi , Fujiwara Akira
Published: July 2016

High-speed and high-accuracy pumping of a single electron is crucial for realizing an accurate current source, which is a promising candidate for a quantum current standard. Here, using a high-accuracy measurement system traceable to primary standards, we evaluate the accuracy of a Si tunable-barrier single-electron pump driven by a single sinusoidal signal. The pump operates at frequencies up to 6.5 GHz, producing a current of more than 1 nA. At 1 GHz, the current plateau with a level of about 160 pA is found to be accurate to better than 0.92 ppm (parts per million), which is a record value for 1-GHz operation. At 2 GHz, the current plateau offset from 1ef (∼320 pA) by 20 ppm is observed. The current quantization accuracy is improved by applying a magnetic field of 14 T, and we observe a current level of 1ef with an accuracy of a few ppm. The presented gigahertz single-electron pumping with a high accuracy is an important step towards a metrological current standard.
Slowly changing potential problems in Quantum Mechanics: Adiabatic theorems, ergodic theorems, and scattering
Authors: Fishman S. , Soffer A.
Published: July 2016

We employ the recently developed multi-time scale averaging method to study the large time behavior of slowly changing (in time) Hamiltonians. We treat some known cases in a new way, such as the Zener problem, and we give another proof of the adiabatic theorem in the gapless case. We prove a new uniform ergodic theorem for slowly changing unitary operators. This theorem is then used to derive the adiabatic theorem, do the scattering theory for such Hamiltonians, and prove some classical propagation estimates and asymptotic completeness.
Infrared spectroscopy of molecular ions in selected rotational and spin-orbit states
Authors: Jacovella U. , Agner J. A. , Schmutz H. , Deiglmayr J. , Merkt F.
Published: July 2016

First results are presented obtained with an experimental setup developed to record IR spectra of rotationally state-selected ions. The method we use is a state-selective version of a method developed by Schlemmer et al. [Int. J. Mass Spectrom. 185, 589 (1999); J. Chem. Phys. 117, 2068 (2002)] to record IR spectra of ions. Ions are produced in specific rotational levels using mass-analyzed-threshold-ionization spectroscopy. The state-selected ions generated by pulsed-field ionization of Rydberg states of high principal quantum number (n ≈ 200) are extracted toward an octupole ion guide containing a neutral target gas. Prior to entering the octupole, the ions are excited by an IR laser. The target gas is chosen so that only excited ions react to form product ions. These product ions are detected mass selectively as a function of the IR laser wavenumber. To illustrate this method, we present IR spectra of C2H2+ in selected rotational levels of the 2Πu,3/2 and 2Πu,1/2 spin-orbit components of the vibronic ground state.
Long-lived coherence in pentafluorobenzene as a probe of ππ* – πσ* vibronic coupling
Authors: Hüter O. , Sala M. , Neumann H. , Zhang S. , Studzinski H. , Egorova D. , Temps F.
Published: July 2016

The dynamics of pentafluorobenzene after femtosecond laser excitation to the optically bright ππ* first excited electronic state have been investigated by femtosecond time-resolved time-of-flight mass spectrometry and femtosecond time-resolved photoelectron imaging spectroscopy. The observed temporal profiles exhibit a bi-exponential decay behavior with a superimposed, long-lived, large-amplitude oscillation with a frequency of νosc = 78–74 cm−1 and a damping time of τD = 5–2 ps. On the basis of electronic structure and quantum dynamics calculations, the oscillations have been shown to arise due to vibronic coupling between the optically bright ππ* state and the energetically close-lying optically dark πσ* state. The coupling leads to a pronounced double-well character of the lowest excited adiabatic potential energy surface along several out-of-plane modes of b1 symmetry. The optical electronic excitation initiates periodic wavepacket motion along these modes. In the out-of-plane distorted molecular configuration, the excited state acquires substantial πσ* character, thus modulating the ionization probability. The photoelectron spectra and the anisotropy of their angular distribution confirm the periodically changing electronic character. The ionizing probe laser pulse directly maps the coupled electron-nuclear motion into the observed signal oscillations.
A solid-state dedicated circularly polarized luminescence spectrophotometer: Development and application
Authors: Harada Takunori , Hayakawa Hiroshi , Watanabe Masayuki , Takamoto Makoto
Published: July 2016

A new solid-state dedicated circularly polarized luminescence (CPL) instrument (CPL-200CD) was successfully developed for measuring true CPL spectra for optically anisotropic samples on the basis of the Stokes–Mueller matrix approach. Electric components newly installed in the CPL-200CD include a pulse motor-driven sample rotation holder and a 100 kHz lock-in amplifier to achieve the linearly polarized luminescence measurement, which is essential for obtaining the true CPL signal for optically anisotropic samples. An acquisition approach devised for solid-state CPL analysis reduces the measurement times for a data set by ca. 98% compared with the time required in our previous method. As a result, the developed approach is very effective for samples susceptible to light-induced degradation. The theory and implementation of the method are described, and examples of its application to a CPL sample with macroscopic anisotropies are provided. An important advantage of the developed instrument is its ability to obtain molecular information for both excited and ground states because circular dichroism measurements can be performed by switching the monochromatic light to white light without rearrangement of the sample.
Full-dimensional global potential energy surfaces describing abstraction and exchange for the H + H2S reaction
Authors: Lu Dandan , Li Jun
Published: July 2016

For the H + H2S system, ∼34 000 data points are sampled over a large configuration space including both abstraction and exchange channels, and calculated at the level of explicitly correlated unrestricted coupled cluster method with singles, doubles, and perturbative triples excitations with the augmented correlation-consistent polarized triple zeta basis set (UCCSD(T)-F12a/aug-cc-pVTZ). The data set was fit using the newly proposed permutation invariant polynomial-neural network (PIP-NN) method with three different vectors as the input: two redundant sets of PIPs, one with the maximum order four (PES-I) and one with the maximum order three (PES-II), and nine non-redundant PIPs (PES-III). All these PESs show small fitting errors and essentially the same performance in representing the title system. Various kinetics and dynamical properties are calculated using the tunneling corrected transition state theory and quasi-classical trajectory, and compared with available experimental results. At a collision energy of 10 kcal/mol, both the H2 and SH products are found to be internally cold, with ∼20% of H2 at its first vibrational excited state, while SH is essentially a spectator. The angular distributions of the products are mainly in backward with considerable contributions from sideway direction. In addition, analytical partial derivatives of any PIP-NN PES with respect to the coordinates of atoms are derived by making use of the monomial symmetrization algorithm [Z. Xie and J. M. Bowman, J. Chem. Theory Comput. 6, 26–34 (2010)]. It can not only accelerate the evaluation of the derivatives, but also improve the energy convergence significantly.
Thermally and vibrationally induced conformational isomerizations, infrared spectra, and photochemistry of gallic acid in low-temperature matrices
Authors: Justino Licínia L. G. , Reva Igor , Fausto Rui
Published: July 2016

Near-infrared (near-IR) narrowband selective vibrational excitation and annealing of gallic acid (3,4,5-trihydroxybenzoic acid) isolated in cryogenic matrices were used to induce interconversions between its most stable conformers. The isomerizations were probed by infrared spectroscopy. An extensive set of quantum chemical calculations, carried out at the DFT(B3LYP)/6-311++G(d,p) level of approximation, was used to undertake a detailed analysis of the ground state potential energy surface of the molecule. This investigation of the molecule conformational space allowed extracting mechanistic insights into the observed annealing- or near-IR-induced isomerization processes. The infrared spectra of the two most stable conformers of gallic acid in N2, Xe, and Ar matrices were fully assigned. Finally, the UV-induced photochemistry of the matrix isolated compound was investigated.
The thermal decomposition of the benzyl radical in a heated micro-reactor. II. Pyrolysis of the tropyl radical
Authors: Buckingham Grant T. , Porterfield Jessica P. , Kostko Oleg , Troy Tyler P. , Ahmed Musahid , Robichaud David J. , Nimlos Mark R. , Daily John W. , Ellison G. Barney
Published: July 2016

Cycloheptatrienyl (tropyl) radical, C7H7, was cleanly produced in the gas-phase, entrained in He or Ne carrier gas, and subjected to a set of flash-pyrolysis micro-reactors. The pyrolysis products resulting from C7H7 were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by infrared absorption spectroscopy. Pyrolysis pressures in the micro-reactor were roughly 200 Torr and residence times were approximately 100 μs. Thermal cracking of tropyl radical begins at 1100 K and the products from pyrolysis of C7H7 are only acetylene and cyclopentadienyl radicals. Tropyl radicals do not isomerize to benzyl radicals at reactor temperatures up to 1600 K. Heating samples of either cycloheptatriene or norbornadiene never produced tropyl (C7H7) radicals but rather only benzyl (C6H5CH2). The thermal decomposition of benzyl radicals has been reconsidered without participation of tropyl radicals. There are at least three distinct pathways for pyrolysis of benzyl radical: the Benson fragmentation, the methyl-phenyl radical, and the bridgehead norbornadienyl radical. These three pathways account for the majority of the products detected following pyrolysis of all of the isotopomers: C6H5CH2, C6H5CD2, C6D5CH2, and C6H513CH2. Analysis of the temperature dependence for the pyrolysis of the isotopic species (C6H5CD2, C6D5CH2, and C6H513CH2) suggests the Benson fragmentation and the norbornadienyl pathways open at reactor temperatures of 1300 K while the methyl-phenyl radical channel becomes active at slightly higher temperatures (1500 K).
Infrared absorption of t-HOCO+, H+(CO2)2, and HCO2− produced in electron bombardment of CO2 in solid para-H2
Authors: Das Prasanta , Tsuge Masashi , Lee Yuan-Pern
Published: July 2016

We have employed electron bombardment during matrix deposition of CO2 (or 13CO2, C18O2) and para-hydrogen (p-H2) at 3.2 K and recorded infrared (IR) spectra of t-HOCO+, H+(CO2)2, HCO2−, CO2−, t-HOCO, and other species isolated in solid p-H2. After the matrix was maintained in darkness for 13 h, intensities of absorption features of t-HOCO+ at 2403.5 (ν1), 2369.9 (ν2), 1018.1 (ν4), and 606.5 (ν6) cm−1 and those of H+(CO2)2 at 1341.1, 883.6, and 591.5 cm−1 decreased. Corresponding lines of isotopologues were observed when 13CO2 or C18O2 replaced CO2. In contrast, lines of HCO2− at 2522.4 (ν1), 1616.1 (ν5), 1327.9 (ν2), and 745.6 (ν3) cm−1 increased in intensity; corresponding lines of H13CO2− or HC18O2− were also observed. Lines of t-DOCO+ and DCO2− were observed in an electron bombarded CO2 /normal-deuterium (n-D2) matrix. Data of ν6 of t-HOCO+ and all observed modes of H18OC18O+ and HC18O2− are new. The assignments were made according to expected chemical behavior, observed isotopic shifts, and comparisons with vibrational wavenumbers and relative intensities of previous reports and calculations with the B3PW91/aug-cc-pVQZ method. The ν1 line of t-HOCO+ in solid p-H2 (2403.5 cm−1), similar to the line at 2673 cm−1 of t-HOCO+ tagged with an Ar atom, is significantly red-shifted from that reported for gaseous t-HOCO+ (3375.37 cm−1) due to partial proton sharing between CO2 and H2 or Ar. The ν1 line of HCO2− in solid p-H2 (2522.4 cm−1) is blue shifted from that reported for HCO2− in solid Ne (2455.7 cm−1) and that of HCO2− tagged with Ar (2449 cm−1); this can be explained by the varied solvation effects by Ne, Ar, or H2 on the mixing of H+ + CO2 and H + CO2− surfaces. Possible formation mechanisms of t-HOCO+, H+(CO2)2, HCO2−, CO2−, t-HOCO, H2O, and t-HCOOH are discussed.
A semi-analytical calculation of the electrostatic pair interaction between nonuniformly charged colloidal spheres at an air-water interface
Authors: Lian Zengju
Published: July 2016

We study the electrostatic pair interaction between two nonuniformly like-charged colloidal spheres trapped in an air-water interface. Under the linear Poisson-Boltzmann approximation, a general form of the electrostatic potential for the system is shown in terms of multipole expansions. After combining the translation-rotation transform of the coordinates with the numerical multipoint collection, we give a semi-analytical result of the electrostatic pair interaction between the colloids. The pair interaction changes quantitatively or even qualitatively with different distributions of the surface charges on the particles. Because of the anisotropic distribution of the surface charge and the asymmetric dielectric medium, the dipole moment of the ion cloud associating with the particle orients diagonally to the air-water interface with an angle α. When the angle is large, the colloids interact repulsively, while they attract each other when the angle is small. The attractive colloids may be “Janus-like” charged and be arranged with some specific configurations. Whatever the repulsions or the attractions, they all decay asymptotically ∝1/d3 (d is the center-center distance of the particles) which is consistent with our general acknowledge. The calculation results also provide an insight of the effect of the ion concentration, particle size, and the total charge of the particle on the pair interaction between the particles.
Intercode comparison of gyrokinetic global electromagnetic modes
Authors: Görler T. , Tronko N. , Hornsby W. A. , Bottino A. , Kleiber R. , Norscini C. , Grandgirard V. , Jenko F. , Sonnendrücker E.
Published: July 2016

Aiming to fill a corresponding lack of sophisticated test cases for global electromagnetic gyrokinetic codes, a new hierarchical benchmark is proposed. Starting from established test sets with adiabatic electrons, fully gyrokinetic electrons, and electrostatic fluctuations are taken into account before finally studying the global electromagnetic micro-instabilities. Results from up to five codes involving representatives from different numerical approaches as particle-in-cell methods, Eulerian and Semi-Lagrangian are shown. By means of spectrally resolved growth rates and frequencies and mode structure comparisons, agreement can be confirmed on ion-gyro-radius scales, thus providing confidence in the correct implementation of the underlying equations.
Stokesian swimming of a sphere at low Reynolds number by helical surface distortion
Authors: Felderhof B. U. , Jones R. B.
Published: July 2016

Explicit expressions are derived for the matrices determining the mean translational and rotational swimming velocities and the mean rate of dissipation for Stokesian swimming at low Reynolds number of a distorting sphere in a viscous incompressible fluid. As an application, an efficient helical propeller-type stroke is found and its properties are calculated.
Dynamic signature of molecular association in methanol
Authors: Bertrand C. E. , Self J. L. , Copley J. R. D. , Faraone A.
Published: July 2016

Quasielastic neutron scattering measurements and molecular dynamics simulations were combined to investigate the collective dynamics of deuterated methanol, CD3OD. In the experimentally determined dynamic structure factor, a slow, non-Fickian mode was observed in addition to the standard density-fluctuation heat mode. The simulation results indicate that the slow dynamical process originates from the hydrogen bonding of methanol molecules. The qualitative behavior of this mode is similar to the previously observed α-relaxation in supercooled water [M. C. Bellissent-Funel et al., Phys. Rev. Lett. 85, 3644 (2000)] which also originates from the formation and dissolution of hydrogen-bonded associates (supramolecular clusters). In methanol, however, this mode is distinguishable well above the freezing transition. This finding indicates that an emergent slow mode is not unique to supercooled water, but may instead be a general feature of hydrogen-bonding liquids and associating molecular liquids.
Time-resolved single-photon detection module based on silicon photomultiplier: A novel building block for time-correlated measurement systems
Authors: Martinenghi E. , Di Sieno L. , Contini D. , Sanzaro M. , Pifferi A. , Dalla Mora A.
Published: July 2016

We present the design and preliminary characterization of the first detection module based on Silicon Photomultiplier (SiPM) tailored for single-photon timing applications. The aim of this work is to demonstrate, thanks to the design of a suitable module, the possibility to easily exploit SiPM in many applications as an interesting detector featuring large active area, similarly to photomultipliers tubes, but keeping the advantages of solid state detectors (high quantum efficiency, low cost, compactness, robustness, low bias voltage, and insensitiveness to magnetic field). The module integrates a cooled SiPM with a total photosensitive area of 1 mm2 together with the suitable avalanche signal read-out circuit, the signal conditioning, the biasing electronics, and a Peltier cooler driver for thermal stabilization. It is able to extract the single-photon timing information with resolution better than 100 ps full-width at half maximum. We verified the effective stabilization in response to external thermal perturbations, thus proving the complete insensitivity of the module to environment temperature variations, which represents a fundamental parameter to profitably use the instrument for real-field applications. We also characterized the single-photon timing resolution, the background noise due to both primary dark count generation and afterpulsing, the single-photon detection efficiency, and the instrument response function shape. The proposed module can become a reliable and cost-effective building block for time-correlated single-photon counting instruments in applications requiring high collection capability of isotropic light and detection efficiency (e.g., fluorescence decay measurements or time-domain diffuse optics systems).
Tunable optoelectronic properties of pulsed dc sputter-deposited ZnO:Al thin films: Role of growth angle
Authors: Kumar Mohit , Singh Ranveer , Nandy Suman , Ghosh Arnab , Rath Satchidananda , Som Tapobrata
Published: July 2016

In this paper, we investigate the role of deposition angle on the physical properties and work function of pulsed dc sputter-deposited Al-doped zinc oxide (AZO) thin films. It is observed that average grain size and crystal quality increase with higher angle of deposition, yielding improved optical properties. A systematic blue shift as well as a decrease in the resistivity takes place with the increasing growth angle up to 70°, while an opposite trend is observed beyond that. In addition, the work function of AZO films is also measured using Kelvin probe force microscopy, which corroborates well with the optical and structural properties. The observed results are explained in the framework of growth angle induced diffusion and shadowing effects. The films deposited at higher angles will be important for rapid incorporation into new technological applications that require a transparent conductive oxide.
Introducing natural thermoplastic shellac to microfluidics: A green fabrication method for point-of-care devices
Authors: Lausecker R. , Badilita V. , Gleißner U. , Wallrabe U.
Published: July 2016

We present a sustainable fabrication method for cheap point-of-care microfluidic systems, employing hot embossing of natural shellac as a key feature of an energy-efficient fabrication method that exclusively uses renewable materials as consumables. Shellac is a low-cost renewable biomaterial that features medium hydrophilicity (e.g., a water contact angle of ca. 73°) and a high chemical stability with respect to common solvents such as cyclohexane or toluene, rendering it an interesting candidate for low-cost microfluidics and a competitor to well-known systems such as paper-based or polydimethylsiloxane-based microfluidics. Moreover, its high replication accuracy for small features down to 30 μm lateral feature size and its ability to form smooth surfaces (surface roughness Ra = 29 nm) at low embossing temperatures (glass transition temperature Tg = 42.2 °C) enable energy-efficient hot embossing of microfluidic structures. Proof-of-concept for the implementation of shellac hot embossing as a green fabrication method for microfluidic systems is demonstrated through the successful fabrication of a microfluidic test setup and the assessment of its resource consumption.
A miniaturized two-DOF rotational gyro with a ball-joint supported permanent magnet rotor
Authors: Li Hai , Liu Xiaowei , Chen Weiping , Zhang Haifeng
Published: July 2016

We proposed a miniaturized two-degrees of freedom (DOF) rotational gyro with a ball-joint supported permanent magnet rotor. The structural design and the dynamic model of the gyro are presented and analyzed in detail in this paper and testified by preliminary experiments. When the rotor tilts away from its null position, it will be constrained by a contactless magnetic equivalent elastic torque derived from the driving structure. As a rotational gyro, this structure is very simple and small, with a core size less than 6 cm3, and it needs only 0.75 W to keep the rotor spinning at a speed of 15 000 revolutions per minute (rpm) in a standard air pressure condition. Preliminary measurements show that, at 7000 rpm within a full scale of ±100 °/s, the gyro has a scale factor of 18.69 mV/(°/s), and a nonlinearity of 0.33% is also achieved through calculation. The results show that the gyro can be used to measure two DOFs' angular rates of carriers without close-loop control due to the existence of magnetic equivalent elasticity.
Capillary-inertial colloidal catapults upon drop coalescence
Authors: Chavez Roger L. , Liu Fangjie , Feng James J. , Chen Chuan-Hua
Published: July 2016

Surface energy released upon drop coalescence is known to power the self-propelled jumping of liquid droplets on superhydrophobic solid surfaces, and the jumping droplets can additionally carry colloidal payloads toward self-cleaning. Here, we show that drop coalescence on a spherical particle leads to self-propelled launching of the particle from virtually any solid surface. The main prerequisite is an intermediate wettability of the particle, such that the momentum from the capillary-inertial drop coalescence process can be transferred to the particle. By momentum conservation, the launching velocity of the particle-drop complex is proportional to the capillary-inertial velocity based on the drop radius and to the fraction of the liquid mass in the total mass. The capillary-inertial catapult is not only an alternative mechanism for removing colloidal contaminants, but also a useful model system for studying ballistospore launching.
Apparent performance ratio of photovoltaic systems—A methodology for evaluation of photovoltaic systems across a region
Authors: Brecl Kristijan , Topič Marko
Published: July 2016

Most of the photovoltaic (PV) solar systems track none or only basic monitoring data, thus the investor has no or limited information about the performance, quality, and reliability of a PV system. In this paper, we report on a methodology to evaluate a large number of PV systems on a regional or even countrywide level. The methodology is based on an apparent performance ratio, a factor close to the temperature compensated performance ratio, although based on solar irradiation data from the closest meteorological station. The methodology is compared to a more detailed evaluation procedure and a comprehensive evaluation of a PV system where all the required—both electrical and meteorological—data are monitored. The results confirm that the apparent performance ratio is very similar to the temperature compensated performance ratio of a PV system.
Matrix product operators, matrix product states, and ab initio density matrix renormalization group algorithms
Authors: Chan Garnet Kin-Lic , Keselman Anna , Nakatani Naoki , Li Zhendong , White Steven R.
Published: July 2016

Current descriptions of the ab initio density matrix renormalization group (DMRG) algorithm use two superficially different languages: an older language of the renormalization group and renormalized operators, and a more recent language of matrix product states and matrix product operators. The same algorithm can appear dramatically different when written in the two different vocabularies. In this work, we carefully describe the translation between the two languages in several contexts. First, we describe how to efficiently implement the ab initio DMRG sweep using a matrix product operator based code, and the equivalence to the original renormalized operator implementation. Next we describe how to implement the general matrix product operator/matrix product state algebra within a pure renormalized operator-based DMRG code. Finally, we discuss two improvements of the ab initio DMRG sweep algorithm motivated by matrix product operator language: Hamiltonian compression, and a sum over operators representation that allows for perfect computational parallelism. The connections and correspondences described here serve to link the future developments with the past and are important in the efficient implementation of continuing advances in ab initio DMRG and related algorithms.
Loss of acoustic black hole effect in a structure of finite size
Authors: Tang Liling , Cheng Li
Published: July 2016

The Acoustic Black Hole (ABH) effect takes place in thin-walled structures with diminishing thickness as a result of the reduction in the bending wave speed. It was shown to exist as a broadband phenomenon, based on wave propagation theory in structures of semi-infinite size. The ABH effect exhibits appealing features for various applications, such as passive vibration control, energy harvesting, and sound radiation control. In this paper, we demonstrate the disappearance of the ABH effect in a finite beam at specific frequency ranges above the cut-on frequency, both experimentally and theoretically. Analyses show that the phenomenon takes place at frequencies which are close to the low order local resonant frequencies of the portion of the beam demarcated by the position of the excitation force. These frequencies can be predicted so that the phenomenon can be avoided for the targeted frequency ranges in ABH applications.
Electron transport mechanisms in polymer-carbon sphere composites
Authors: Nieves Cesar A. , Ramos Idalia , Pinto Nicholas J. , Zimbovskaya Natalya A.
Published: July 2016

A set of uniform carbon microspheres (CSs) whose diameters have the order of 0.125 μm to 10 μm was prepared from aqueous sucrose solution by means of hydrothermal carbonization of sugar molecules. A pressed pellet was composed by mixing CSs with polyethylene oxide (PEO). Electrical characterization of the pellet was carried out showing Ohmic current-voltage characteristics and temperature-dependent conductivity in the range of 80 K<T<300 K. The conductivity reached a maximum value of 0.24 S/cm at 258 K. The dependence of conductivity on temperature was theoretically analyzed to determine predominating mechanisms of electron transport. It was shown that thermally induced electron tunneling between adjacent spheres may take on an important part in the electron transport through the CS/PEO composites.
Transport mechanism through metal-cobaltite interfaces
Authors: Acha C. , Schulman A. , Boudard M. , Daoudi K. , Tsuchiya T.
Published: July 2016

The resistive switching (RS) properties as a function of temperature were studied for Ag/La1−xSrxCoO3 (LSCO) interfaces. The LSCO is a fully relaxed 100 nm film grown by metal organic deposition on a LaAlO3 substrate. Both low and a high resistance states were set at room temperature, and the temperature dependence of their current-voltage (IV) characteristics was measured taking care to avoid a significant change of the resistance state. The obtained non-trivial IV curves of each state were well reproduced by a circuit model which includes a Poole-Frenkel element and two ohmic resistances. A microscopic description of the changes produced by the RS is given, which enables to envision a picture of the interface as an area where conductive and insulating phases are mixed, producing Maxwell-Wagner contributions to the dielectric properties.
Experimental demonstration of water based tunable metasurface
Authors: Odit Mikhail , Kapitanova Polina , Andryieuski Andrei , Belov Pavel , Lavrinenko Andrei V.
Published: July 2016

A simple dynamically tunable metasurface (two-dimensional metamaterial) operating at microwave frequencies is developed and experimentally investigated. Conceptually, the simplicity of the approach is granted by reconfigurable properties of unit cells partially filled with distilled water. The transmission spectra of the metasurface for linear and circular polarizations of the incident wave were experimentally measured under the metasurface rotation around a horizontal axis. The changes in the transmission coefficient magnitude up to 8 dB at 1.25 GHz are reported while rotating the metasurface by the 90° angle. The proposed approach manifests the cheap and accessible route for the electromagnetic wave control in the microwave region with the help of metasurfaces.
Insulator-protected mechanically controlled break junctions for measuring single-molecule conductance in aqueous environments
Authors: Muthusubramanian N. , Galan E. , Maity C. , Eelkema R. , Grozema F. C. , van der Zant H. S. J.
Published: July 2016

We present a method to fabricate insulated gold mechanically controlled break junctions (MCBJ) by coating the metal with a thin layer of aluminum oxide using plasma enhanced atomic layer deposition. The Al2O3 thickness deposited on the MCBJ devices was varied from 2 to 15 nm to test the suppression of leakage currents in deionized water and phosphate buffered saline. Junctions coated with a 15 nm thick oxide layer yielded atomically sharp electrodes and negligible conductance counts in the range of 1 to 10−4 G0 (1 G0 = 77 μS), where single-molecule conductances are commonly observed. The insulated devices were used to measure the conductance of an amphiphilic oligophenylene ethynylene derivative in deionized water.
Magnetofluidic concentration and separation of non-magnetic particles using two magnet arrays
Authors: Hejazian Majid , Nguyen Nam-Trung
Published: July 2016

The present paper reports the use of diluted ferrofluid and two arrays of permanent magnets for the size-selective concentration of non-magnetic particles. The micro magnetofluidic device consists of a straight channels sandwiched between two arrays of permanent magnets. The permanent magnets create multiple capture zones with minimum magnetic field strength along the channel. The complex interaction between magnetic forces and hydrodynamic force allows the device to operate in different regimes suitable for concentration of non-magnetic particles with small difference in size. Our experimental results show that non-magnetic particles with diameters of 3.1 μm and 4.8 μm can be discriminated and separated with this method. The results from this study could be used as a guide for the design of size-sensitive separation devices for particle and cell based on negative magnetophoresis.
Relationships between the activity of respiratory-chain complexes in pre- (biopsy) or post-slaughter muscle samples and feed efficiency in random-bred Ghezel lambs
Authors: Zamiri M. J. , Mehrabi R. , Kavoosi G. R. , Sharifabadi H. Rajaei
Published: July 2016

The present study was conducted to determine the relationship between the activity of mitochondrial respiratory chain complexes in pre- and post-slaughter muscle samples and residual feed intake (RFI) in Ghezel male lambs born as a result of random mating. The study was based on the hypothesis that random-bred lambs with lower feed (or higher) RFI have lower (or higher) respiratory chain-complex activity in muscle samples. Lambs (n = 30) were fed a diet consisting of 70% concentrate and 30% alfalfa hay during a 70-day period. Individual feed intake and average daily gain were recorded to calculate the RFI, feed-conversion ratio (FCR) and adjusted FCR (aFCR). On the basis of these calculations, the lambs were classified into low and high groups for RFI, with FCR and aFCR (n = 22) being one standard deviation above or below the means; this was corroborated by Student’s t-test (P < 0.01). At the end of the experiment, a 10-g biopsy sample was taken from the posterior side of the left femoral biceps. After 24 h, the lambs were slaughtered, and a sample from the posterior side of the right femoral biceps was dissected for determination of mitochondrial protein and respiratory chain-complex activities (Complexes I–V). The RFI was not correlated with the metabolic bodyweight and average daily gain, but was positively correlated (r = 0.56) with the average daily feed intake (P < 0.01); mean daily feed intake in the low-RFI group was 200 g less than that in the high-RFI group. The FCR and aFCR were not significantly (P > 0.05) correlated with average daily feed intake (r = 0.39 and r = 0.36 respectively), but showed a negative correlation (P < 0.01) with average daily gain (r = –0.73 and r = –0.76 respectively). Although very high negative correlations were recorded between the activities of all five respiratory-chain complexes and RFI in muscle samples obtained before (–0.91 to –0.97) and after (–0.92 to –0.97) slaughter, Complexes I and V showed small negative correlations (–0.40) with FCR or aFCR (P < 0.05). Enzyme activities of the respiratory-chain Complexes I, III and V were not significantly different between the pre- and post-slaughter biopsy samples; however, the enzyme activities of respiratory-chain Complexes II and IV were slightly higher in post-slaughter samples (P < 0.01). These results suggested that it may be possible to use the enzymatic activity of respiratory-chain complexes in muscle biopsy samples for screening of lambs for RFI, providing a useful procedure for genetic selection of lambs for this component of feed efficiency. These encouraging results need to be verified in further experiments using other sheep breeds and a larger number of lambs.
Resource use and greenhouse gas emissions from grain-finishing beef cattle in seven Australian feedlots: a life cycle assessment
Authors: Wiedemann Stephen , Davis Rod , McGahan Eugene , Murphy Caoilinn , Redding Matthew
Published: July 2016

Grain finishing of cattle has become increasingly common in Australia over the past 30 years. However, interest in the associated environmental impacts and resource use is increasing and requires detailed analysis. In this study we conducted a life cycle assessment (LCA) to investigate impacts of the grain-finishing stage for cattle in seven feedlots in eastern Australia, with a particular focus on the feedlot stage, including the impacts from producing the ration, feedlot operations, transport, and livestock emissions while cattle are in the feedlot (gate-to-gate). The functional unit was 1 kg of liveweight gain (LWG) for the feedlot stage and results are included for the full supply chain (cradle-to-gate), reported per kilogram of liveweight (LW) at the point of slaughter. Three classes of cattle produced for different markets were studied: short-fed domestic market (55–80 days on feed), mid-fed export (108–164 days on feed) and long-fed export (>300 days on feed). In the feedlot stage, mean fresh water consumption was found to vary from 171.9 to 672.6 L/kg LWG and mean stress-weighted water use ranged from 100.9 to 193.2 water stress index eq. L/kg LWG. Irrigation contributed 57–91% of total fresh water consumption with differences mainly related to the availability of irrigation water near the feedlot and the use of irrigated feed inputs in rations. Mean fossil energy demand ranged from 16.5 to 34.2 MJ lower heating values/kg LWG and arable land occupation from 18.7 to 40.5 m2/kg LWG in the feedlot stage. Mean greenhouse gas (GHG) emissions in the feedlot stage ranged from 4.6 to 9.5 kg CO2-e/kg LWG (excluding land use and direct land-use change emissions). Emissions were dominated by enteric methane and contributions from the production, transport and milling of feed inputs. Linear regression analysis showed that the feed conversion ratio was able to explain >86% of the variation in GHG intensity and energy demand. The feedlot stage contributed between 26% and 44% of total slaughter weight for the classes of cattle fed, whereas the contribution of this phase to resource use varied from 4% to 96% showing impacts from the finishing phase varied considerably, compared with the breeding and backgrounding. GHG emissions and total land occupation per kilogram of LWG during the grain finishing phase were lower than emissions from breeding and backgrounding, resulting in lower life-time emissions for grain-finished cattle compared with grass finishing.