bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of Some Interleukins in Cerebrospinal Fluid in Children with Meningitis
Authors: R. Sarhat Entedhar , N. M Albarzanji Zubaidah , I. Ali Pambuk Chateen
Published: January 2020

Meningitis is often associated with cerebral compromise which may be responsible for neurological squeal in nearly half of the survivors. Little is known about the mechanisms of CNS involvement in bacterial meningitis. the current study was to analyze the clinical significance of cerebrospinal fluid (CSF) concentrations of interleukin (IL)- 6, IL-1, IL-8, IL-10, tumor necrosis factor-alpha (TNF-α), and C-reactive protein in children with meningitis (n=35) and compared with control subjects (n=28). Serum total protein, interleukine-6, IL-1 , IL-8, IL-10 , and, CRP, and TNF-α levels were found to be significantly high in study group, whereas serum glucose IL-10 levels were significantly low comparing with control group. Positive correlation was observed between IL-6with glucose , CRP , and IL-8 , also between IL-10 with protein , TNF with IL-8 ,and IL-1 with CRP . whereas there was negative correlation between IL-6 with protein , TNF , IL-1 , IL-10 , also between IL-1 with IL-8 ,between IL-10 with, and TNF , IL-10 with glucose . More studies performed in suitable models of meningitis are required in order to establish the routine use of inflammatory markers in the diagnosis of infectious diseases of the central nervous system
Temperature dependence of collisional broadening and shift for the Kr 4p6S01→5p[3/2]2 electronic transition
Authors: Sahoo Abinash , Zelenak Dominic , Narayanaswamy Venkateswaran
Published: January 2020

Temperature scaling of collisional broadening parameters for krypton
(absorber)

4

p
6

S
0
1

→
5
p

[
3

/

2

]
2

electronic transition centered at
107.3 nm in the presence of major combustion species (perturber) is
investigated. The absorption spectrum in the vicinity of the
transition is obtained from the fluorescence due to the two-photon
excitation scan of krypton. Krypton was added in small amounts to
major combustion species such as

C
H

4

,

C
O

2

,

N

2

, and air, which then heated to
elevated temperatures when flowed through a set of heated coils. In a
separate experimental campaign, laminar premixed flat flame product
mixtures of methane combustion were employed to extend the
investigations to higher temperature ranges relevant to combustion.
Collisional full width half maximum (FWHM) (

w
C

) and shift (

δ
C

) were computed from the absorption
spectrum by synthetically fitting Voigt profiles to the excitation
scans, and their corresponding temperature scaling was determined by
fitting power-law temperature dependencies to the

w
C

and

δ
C

data for each perturber species. The
temperature exponents of

w
C

and

δ
C

for all considered combustion species
(perturbers) were

−

0.73

and

−

0.6

, respectively. Whereas the
temperature exponents of

w
C

are closer to the value (

−

0.7

) predicted by the dispersive
interaction collision theory, the corresponding exponents of

δ
C

are in between the dispersive
interaction theory and the kinetic theory of hard-sphere collisions.
Comparison with existing literature on broadening parameters of NO,
OH, and CO laser-induced fluorescence spectra reveal interesting
contributions from non-dispersive interactions on the temperature
exponent.
Characterization of fuel/water mixtures and emulsions with ethanol using laser-induced fluorescence
Authors: Koegl Matthias , Mull Christopher , Mishra Yogeshwar Nath , Will Stefan , Zigan Lars
Published: January 2020

In charged spark-ignition engines, additional water injection allows for the reduction of temperature under stoichiometric mixture conditions. However, a higher complexity of the injection and combustion processes is introduced when a mixture of fuel and water (“emulsion”) is injected directly into the combustion chamber using the same injector. For this purpose, the mixture must be homogenized before injection so that a reproducible composition can be adjusted. In principle, gasoline and water are not miscible, and may form an unstable macro-emulsion during mixing. However, the addition of ethanol, which is a biofuel component that is admixed to gasoline, can improve the mixing and may lead to a stable micro-emulsion. For the assessment of the distribution of the water and fuel phases in the mixture, a novel imaging concept based on laser-induced fluorescence (LIF) is proposed. In a first spectroscopic study, a fluorescence dye for imaging of the water phase is selected and evaluated. The fluorescence spectra of the dye dissolved in pure water are investigated under varied conditions using a simplified pressure cell equipped with a stirrer. The study comprises effects of temperature, dye concentration, and photo-dissociation on fluorescence signals. In a second step, fuel is mixed with water (5 vol. % to 10 vol. %) containing the dye, and the water dispersion in the fuel is investigated in an imaging study. Additionally, the miscibility of fuel and water is studied for varying ethanol content, and the homogeneity of the mixture is determined. These first investigations are also essential for the assessment of the potential of the LIF technique for studying the distribution of the water phase in internal combustion engine injection systems and sprays.
Analysis of antimagnetic interference properties and structural optimization of magneto-optical glass current sensors
Authors: Li Yansong , Wan Jun , Zhang Weiwei , Liu Jun
Published: January 2020

To solve the issue of external magnetic fields interfering with
magneto-optical glass current sensors (MOCS), this paper proposes a
strip-like splicing structure. First, a mathematical model for
integrating the magnetic field strength along the optical path is
constructed, and the relationship between the gap size

a

, the
interference source distance

d

, the angle of the
interference source

θ

, and the relative error

ε

is analyzed. Then, an
optical-electromagnetic COMSOL Multiphysics simulation model is
constructed. The simulation results are in good agreement with the
theoretical results. Finally, the strip-like splicing MOCS structure
is optimized by combining two different MOCSs with a tilt angle of
45°. Thus, their output signals are summed and the adjacent
interference phase signals nearly compensate mutually. This new
structure facilitates real-world installation, avoiding the angle
being limited to a fixed value, and meeting a 0.2 accuracy of the
anti-electromagnetic interference properties.
Polarized skylight compass based on a soft-margin support vector machine working in cloudy conditions
Authors: Liang Huaju , Bai Hongyang , Liu Ning , Sui Xiubao
Published: January 2020

The skylight polarization pattern, which is a result of the scattering of unpolarized sunlight by particles in the atmosphere, can be used by many insects for navigation. Inspired by insects, several polarization navigation sensors have been designed and combined with various heading determination methods in recent years. However, up until now, few of these studies have fully considered the influences of different meteorological conditions, which play key roles in navigation accuracy, especially in cloudy weather. Therefore, this study makes a major contribution to the study on bio-inspired heading determination by designing a skylight compass method to suppress cloud disturbances. The proposed method transforms the heading determination problem into a binary classification problem by segmentation, connected component detection, and inversion. Considering the influences of noise and meteorological conditions, the binary classification problem is solved by the soft-margin support vector machine. In addition, to verify this method, a pixelated polarization compass platform is constructed that can take polarization images at four different orientations simultaneously in real time. Finally, field experimental results show that the designed method can more effectively suppress the interference of clouds compared with other methods.
5 × 25  Gbit/s WDM transmitters based on passivated graphene–silicon electro-absorption modulators
Authors: Alessandri Chiara , Asselberghs Inge , Brems Steven , Huyghebaert Cedric , Van Campenhout Joris , Van Thourhout Dries , Pantouvaki Marianna
Published: January 2020

Today, one of the key challenges of graphene devices is establishing
fabrication processes that can ensure performance stability and
repeatability and that can eventually enable production in high
volumes. In this paper, we use up-scalable fabrication processes to
demonstrate three five-channel wavelength-division multiplexing (WDM)
transmitters, each based on five graphene–silicon electro-absorption
modulators. A passivation-first approach is used to encapsulate
graphene, which results in hysteresis-free and uniform performance
across the five channels of each WDM transmitter, for a total of 15
modulators. Open-eye diagrams are obtained at 25 Gb/s using

2.5

V

p
p

, thus demonstrating potential for
multi-channel data transmission at

5

×

25

G
b

/

s

on each of the three WDM
transmitters.
3D tomographic magnetofluorescence imaging of nanodiamonds
Authors: Frese Claire-Denise , Stephan Schiller and
Published: January 2020

We demonstrate lensless imaging of three-dimensional phantoms of
fluorescent nanodiamonds in solution. Magnetofluorescence imaging is
employed, which relies on a dependence of the fluorescence yield on
the magnetic field, and pervading the object with an inhomogeneous
magnetic field. This field provides a field-free field line, which is
rastered through the object. A 3D image of the object is obtained by
imaging a set of 2D slices. Each 2D slice image is computed from a set
of 1D projections, obtained under different projection directions,
using a backprojection algorithm. Reconstructed images containing up
to 36 × 36 × 8 voxels are
obtained. A spatial resolution better than 2 mm is achieved in
three dimensions. The approach has the potential for scalability.
Measurement and visualization of stimulus-evoked tissue dynamics in mouse barrel cortex using phase-sensitive optical coherence tomography
Authors: Tang Peijun , Li Yuandong , Rakymzhan Adiya , Xie Zhiying , Wang Ruikang K.
Published: January 2020

We describe a method to measure tissue dynamics in mouse barrel cortex
during functional activation via phase-sensitive optical coherence
tomography (PhS-OCT). The method measures the phase changes in OCT
signals, which are induced by the tissue volume change, upon which to
localize the activated tissue region. Phase unwrapping, compensation
and normalization are applied to increase the dynamic range of the OCT
phase detection. To guide the OCT scanning, intrinsic optical signal
imaging (IOSI) system equipped with a green light laser source
(532 nm) is integrated with the PhS-OCT system to provide a
full field time-lapsed images of the reflectance that is used to
identify the transversal 2D localized tissue response in the mouse
brain. The OCT results show a localized decrease in the OCT phase
signal in the activated region of the mouse brain tissue. The decrease
in the phase signal may be originated from the brain tissue
compression caused by the vasodilatation in the activated region. The
activated region revealed in the cross-sectional OCT image is
consistent with that identified by the IOSI imaging, indicating the
phase change in the OCT signals may associate with the changes in the
corresponding hemodynamics. In vivo localized tissue
dynamics in the barrel cortex at depth during whisker stimulation is
observed and monitored in this study.
Demonstration of a hybrid optical fiber–wireless 5G fronthaul coexisting with end-to-end 4G networks
Authors: Mufutau Akeem O. , Guiomar Fernando P. , Fernandes Marco A. , Lorences-Riesgo Abel , Oliveira Arnaldo , Monteiro Paulo P.
Published: January 2020

The plethora of services envisaged to support 5G use-cases requires the development of a radio access network (RAN) infrastructure with the capability to integrate a variety of user-demanded mobile traffic characteristics. It is therefore interesting to study a 5G deployment scenario showcasing heterogeneous transmission. In order to address this challenge, in this paper, we propose and experimentally assess a coarse-wavelength-division-multiplexing-compatible optical access network for joint provisioning of 4G/5G RAN services, supporting the coexistence of both digital and analog radio-over-fiber (ARoF) fronthauling. Resorting to an integrated testbed, we demonstrate the transport of 100 MHz 5G downlink using low-latency and bandwidth-efficient ARoF over 8 km fiber, seamlessly coexisting on the same fronthaul infrastructure with a legacy full-fledged 4G long-term evolution (LTE) network supported by Ethernet-based digital RoF with different functional splits. In addition, we experimentally demonstrate the successful operation of the 4G/5G system in a hybrid fiber–wireless scenario including a free-space optics fronthaul extension with 55 m. The proposed heterogeneous RAN architecture is demonstrated to provide a flexible and robust integration path for novel 5G technologies, enabling their coexistence with currently deployed 4G LTE systems over a shared fronthaul infrastructure.
Frequency- and time-domain analyses of multiple reflections and interference phenomena in a metamaterial absorber
Authors: Nilotpal  , Aman  , Bhattacharyya Somak , Chakrabarti P.
Published: January 2020

The theory of absorption of infrared radiation based on the formation of antiparallel surface current in a metamaterial absorber appears to be invalid when the thickness of the dielectric material in the structure is increased by an integral multiple of a half-wavelength. The absorption characteristics repeat themselves with an increase of each integral multiple of a half-wavelength, despite the fact that the surface current components for an odd value of integers are parallel to each other. This contradicts the theory of absorption based on the formation of antiparallel surface current. The reason for this uncertainty in surface current has been well explored in this paper, wherein we demonstrate theoretically the principle of absorption in a metamaterial structure based on the principle of multiple reflection and the interference model. For validation of the occurrence of the multiple reflection phenomena involved in absorption, time-domain analyses of metamaterial absorbers under normal as well as oblique incidence have been simultaneously analyzed. The time of occurrence of each reflection obtained numerically using the inverse chirp-Z transform is found to be in good agreement with the results obtained analytically.
Multiple-band frequency locking in an acousto-optic system with optoelectronic feedback
Authors: Mantsevich Sergey , Voloshin Andrey , Slinkov Grigory , Kostyleva Ekaterina , Balakshy Vladimir
Published: January 2020

In this paper, we introduce and analyze both experimentally and theoretically multiple-band frequency locking, which becomes possible in an acousto-optic (AO) system with optoelectronic feedback. This effect is observed in a system combining a collinear AO cell and positive electronic feedback. The feedback signal is formed with the optical heterodyning effect, which occurs at the AO cell output and takes place in the special regime of collinear AO diffraction. It is shown for the first time, to the best of our knowledge, that frequency locking is possible in this system when connecting an external RF generator not only in one band near the self-oscillation frequency, but in several bands. The existence of as many as nine frequency-locking bands is predicted. The number of frequency-locking bands and their widths depend on the feedback gain and RF generator signal magnitude.
Propagation dynamics of autofocusing circle Pearcey Gaussian vortex beams in a harmonic potential
Authors: Sun Chao , Deng Dongmei , Yang Xiangbo , Wang Guanghui
Published: January 2020

We introduce the circle Pearcey Gaussian vortex (CPGV) beams in a harmonic potential for the first time and investigate their abruptly autofocusing properties by theoretical analysis and numerical simulations in this paper. By varying the spatial distribution factors, one can effectively control the propagating dynamics of the beams, including the position of the focus, the radius of the focal light spot and the intensity contrast. Meanwhile, the magnitude of topological charges and the position of the vortex can alter the focal pattern and the intensity contrast. Furthermore, the position of the focus can be flexibly controlled in a tiny range by adjusting the scaled parameter of the incident beam properly.
Singleshot polychromatic coherent diffractive imaging with a high-order harmonic source
Authors: Malm Erik , Wikmark Hampus , Pfau Bastian , Villanueva-Perez Pablo , Rudawski Piotr , Peschel Jasper , Maclot Sylvain , Schneider Michael , Eisebitt Stefan , Mikkelsen Anders , L’Huillier Anne , Johnsson Per
Published: January 2020

Singleshot polychromatic coherent diffractive imaging is performed with a high-intensity high-order harmonic generation source. The coherence properties are analyzed and several reconstructions show the shot-to-shot fluctuations of the incident beam wavefront. The method is based on a multi-step approach. First, the spectrum is extracted from double-slit diffraction data. The spectrum is used as input to extract the monochromatic sample diffraction pattern, then phase retrieval is performed on the quasi-monochromatic data to obtain the sample’s exit surface wave. Reconstructions based on guided error reduction (ER) and alternating direction method of multipliers (ADMM) are compared. ADMM allows additional penalty terms to be included in the cost functional to promote sparsity within the reconstruction.
Abruptly autofocusing chirped ring Pearcey Gaussian vortex beams with caustics state in the nonlinear medium
Authors: Zhang Liping , Deng Dongmei , Yang Xiangbo , Wang Guanghui , Liu Hongzhan
Published: January 2020

We simulate the propagation of the abruptly autofocusing chirped ring Pearcey Gaussian vortex (CRPGV) beams with caustics by modulating the phase of a circularly symmetric optical wavefront appropriately. The propagation characteristics of the CRPGV beams are explored in the Kerr medium. Different caustic surfaces of revolution which can be used as optical bottles are formed during the propagation. We also introduce the influence of the initial input power, the chirp factor and the stochastic type perturbations for the CRPGV beams during the propagation. Furthermore, the dynamics of the optical bottle and the breathers-like structures are explored in detail.
Full-field vibration profilometry using time-averaged interference microscopy aided by variational analysis
Authors: Cywińska Maria , Trusiak Maciej , Styk Adam , Patorski Krzysztof
Published: January 2020

Full-field vibration testing is indispensable in characterization of micro-electro-mechanical components. Time-averaged interference (TAI) microscopy is a very capable and accurate vibration profilometry technique. It employs natural all-optical multiplexing of required information, i.e., recorded interferogram is amplitude-modulated by the Bessel pattern, which in turn encodes spatial distribution of vibration amplitude in its underlying phase function. We propose a complete end-to-end numerical scheme for efficient and robust vibration amplitude map demodulation based on the variational data-analysis paradigm. First, interferogram is variationally pre-filtered and complex analytic-interferogram is generated, exploiting the Hilbert spiral transform. The amplitude term of analytic-interferogram is accessed for Besselogram, i.e., TAI amplitude modulation distribution. Next, the Besselogram is variationally pre-filtered and complex analytic-Besselogram is calculated applying the Hilbert spiral transform. Finally, the phase term of the analytic-Besselogram is determined, unwrapped and post-filtered to achieve spatial distribution of vibration amplitude. Proposed approach is verified using simulated interferograms and corroborated upon experimental vibration testing. Reported method compares favorably with the reference Hilbert-Huang transform-based method. The improvement was gained by adding two new steps to the calculation path: (1) additional removal of the interferogram’s residual background and noise and (2) variational based vibration amplitude map error correction method.
Stabilizing DFB laser injection-locked to an external fiber-optic ring resonator
Authors: Spirin Vasily V. , Bueno Escobedo José L. , Korobko Dmitry A. , Mégret Patrice , Fotiadi Andrei A.
Published: January 2020

Self-injection locking to an external fiber cavity is an efﬁcient technique enabling drastic linewidth narrowing and self-stabilization of semiconductor lasers. The main drawback of this technique is its high sensitivity to fluctuations of the configuration parameters and surroundings. In the proposed laser configuration, to the best our knowledge, for the first time the self-injection locking mechanism is used in conjunction with a simple active optoelectronic feedback, ensuring stable mode-hopping free laser operation in a single longitudinal mode. Locking to 4-m length fiber resonator causes a drastic narrowing of the DFB laser linewidth down to 2.8 kHz and a reduction of the laser phase noise by three orders of magnitude. We have explored key features of the laser dynamics with and without active feedback, revealing stability and tunability of the laser linewidth as an additional benefit of the proposed technique.
Improved separated-parameter calibration method for binocular vision measurements with a large field of view
Authors: Zhang Yang , Liu Wei , Wang Fuji , Lu Yongkang , Wang Wenqi , Yang Fan , Jia Zhenyuan
Published: January 2020

Large field-of-view (FOV) calibration is indispensable to ensure the accuracy of vision measurement systems for large aviation components. We propose an improved separated-parameter calibration method for large-FOV binocular vision measurements with a high flexibility and accuracy. Firstly, the camera parameters are separately calibrated according to the sub-area features of image. Subsequently, based on the spatial-calibration accuracy, a stereoscopic calibration object is devised. The mean error of the proposed method is experimentally obtained as 0.13 mm for a FOV of 2.0 m × 1.5 m. Its feasibility and effectiveness for the measurement in the field is validated by workshop calibration.
Wavy nature of collagen fibrils deduced from the dispersion of their second-order nonlinear optical anisotropy parameters ρ
Authors: Rouède Denis , Schaub Emmanuel , Bellanger Jean-Jacques , Ezan Frédéric , Tiaho François
Published: January 2020

From P-SHG experiments, second-order nonlinear optical anisotropy parameters ρ = χ
ZZZ
/χ
ZXX
of collagen tissues are calculated assuming the same model of supercoiled collagen fibril characterized by a variable angle θ. Dispersion of experimental ρ values is converted into distribution of θ values based on the wavy nature of collagen fibrils deduced from EM studies. For tendon, the results show that the dispersion of experimental ρ values is mainly due to Poisson photonic shot noise assuming a slight fibrillar undulation with θ = 2.2° ± 1.8°. However for skin and vessels, the dispersion of experimental ρ values is mainly due to a stronger fibrillar undulation with θ = 16.2° ± 1.3°. The results highlight that this undulation is reduced during the development of liver fibrosis therefore, contributing to the rigidity of the tissue.
Compact adaptive interferometer for unknown freeform surfaces with large departure
Authors: Zhang Lei , Li Chen , Huang Xiaolin , Zhang Yukun , Zhou Sheng , Li Jingsong , Yu Benli
Published: January 2020

The newest experimental validation report of the coverage for the rotationally non-symmetric departure of a freeform surface in adaptive interferometry is about 20 µm. A compact adaptive interferometer is introduced to test unknown freeform surfaces with larger departure. The cascaded DMs (woofer and tweeter) can effectively double the measurable rotationally non-symmetric departure, to ∼80 µm using current DM technology. With a constrained decoupling control algorithm, the woofer and tweeter can averagely share the aberrations without coupling. DM surface monitoring is addressed by a time-division-monitoring (TDM) technique, which avoids separate monitoring devices and configurations and thus makes a compact configuration. Measurements of two different surfaces are presented: a nearly flat freeform with ∼40 um departure, and an off-axis paraboloid with ∼50 um of asymmetric departure.
Contra-directional switching enabled by Si-GST grating
Authors: Hu Hao , Zhang Hanyu , Zhou Linjie , Xu Jian , Lu Liangjun , Chen Jianping , Rahman B. M. A.
Published: January 2020

We present the design, simulation, and experimental demonstration of a Si-GST grating assisted contra-directional coupler for optical switching. The effective refractive index of the GST-loaded silicon waveguide changes significantly when the GST is switched from the amorphous state to the crystalline state, allowing for large tuning of the propagation constant. The two coupled waveguides are designed to satisfy the phase-match condition only at the amorphous state to achieve Bragg reflection at the drop-port. Experimental results show that the device insertion loss is less than 5 dB and the extinction ratio is more than 15 dB with an operation bandwidth of 2.2 nm around the 1576 nm operating wavelength. Due to the nonvolatile property of GST, there is no static power consumption to maintain the two states. It is the first demonstration of a GST-enabled grating coupler that can be switched by phase change material.
Nonparabolicity of size-quantized subbands of bilayer semiconductor quantum wells with heterojunction
Authors: Vovk Ilia A. , Litvin Aleksandr P. , Ushakova Elena V. , Cherevkov Sergei A. , Fedorov Anatoly V. , Rukhlenko Ivan D.
Published: January 2020

This paper presents a theory of size quantization and intersubband optical transitions in bilayer semiconductor quantum wells with asymmetric profile. We show that, in contrast to single-layer quantum wells, the size-quantized subbands of bilayer quantum wells are nonparabolic and characterized by effective masses that depend on the electron wave number and the subband number. It is found that the effective masses are related to the localization of the electron wave function in the layers of the quantum well and can be controlled by varying the chemical composition or geometric parameters of the structure. We also derive an analytical expression for the probability of optical transitions between the subbands of the bilayer quantum well. Our results are useful for the development of laser systems and photodetectors based on colloidal nanoplates and epitaxial layers of semiconductor materials with heterojunctions.
Neural network decoder of polar codes with tanh-based modified LLR over FSO turbulence channel
Authors: Fang Jiafei , Bi Meihua , Xiao Shilin , Yang Guowei , Yang Hang , Chen Zhiyu , Liu Zhiyang , Hu Weisheng
Published: January 2020

The deep learning-based decoder of polar codes is investigated over free space optical (FSO) turbulence channel for the first time. The feedforward neural networks (NN) are adopted to establish the decoder and some custom layers are designed to train the NN decoder over the turbulence channel. The tanh-based modified log-likelihood ratio (LLR) is proposed as the input of NN decoder, which has faster convergence and better bit error rate (BER) performance compared with the standard LLR input. The simulation results show that the BER performance of NN decoder with tanh-based modified LLR is close to the conventional successive cancellation list (SCL) decoder over the turbulence channel, which verifies that the NN decoder with tanh-based modified LLR can learn the encoding rule of polar codes and the characteristics of turbulence channel. Furthermore, the turbulence-stability is investigated and the trained NN decoder in a fixed turbulence condition also has stable performance in other turbulence conditions.
High-efficiency couplers for graphene surface plasmon polaritons in the mid-infrared region
Authors: Ye Longfang , Sui Kehan , Feng Hao
Published: January 2020

We numerically demonstrate a novel, to the best of our knowledge, variety of high-efficiency couplers for mid-infrared graphene surface plasmon polaritons (SPPs). The proposed couplers are composed of a dual-parabolic-tapered transition to compress and couple the SPPs of a GaAs slab waveguide into the graphene layer. The dispersion relation, field distributions, transmittance, and coupling efficiency of the couplers are systematically analyzed. It is found that broadband coupling transmission with a transmittance around 0.3 is achieved for the coupler without a silver substrate. To further reduce radiation and enhance the transmittance, a silver substrate is introduced in the proposed coupler design, which achieves a transmittance over 0.5 ranging from

1960

to

2320

c
m

−
1

with a peak transmittance of 0.75. Furthermore, both couplers with and without a silver substrate achieve a similar coupling efficiency of more than 48% in the whole wavelength range of

1900
−
2400

c
m

−
1

and a coupling efficiency peak of over 80% around

2120

c
m

−
1

. This Letter may provide an efficient excitation method for graphene SPPs, which is of great importance for the development of various graphene plasmonic devices.
Bond additivity model for anisotropic second-harmonic generation from two-dimensional honeycomb lattices
Authors: Lu Fanjin , Sun Zeyuan , Wu Shiwei , Liu Wei-Tao
Published: January 2020

We provide an analytical method for extracting detailed structural information about two-dimensional (2D) honeycomb lattices from optical second-harmonic generation (SHG) anisotropy patterns. When the lattice deviates from the ideal honeycomb structure, we relate the microscopic structural properties, such as bond length and bonding angle, to the macroscopic nonlinear susceptibility tensor based on the molecular bond additivity model. Our method will help quantitative studies of 2D materials with SHG and is readily applied to more general cases.
Engineering with Bound States in the Continuum
Authors: Koshelev Kirill , Bogdanov Andrey , Kivshar Yuri
Published: January 2020

Identified nearly a century ago by early workers in quantum
mechanics, bound states can dramatically reduce radiation from optical
resonators, opening up new application prospects in nanophotonics.
Enhanced laser–plasma interactions using non-imaging optical concentrator targets
Authors: MacPhee Andrew G. , Alessi David , Chen Hui , Cochran Ginevra , Hermann Mark R. , Kalantar Daniel H. , Kemp Andreas J. , Kerr Shaun M. , Link Anthony J. , Ma Tammy , Mackinnon Andrew J. , Mariscal Derek A. , Schlossberg David , Tommasini Riccardo , Vonhof Scott , Widmayer Clifford C. , Wilks Scott C. , Jackson Williams G. , Williams Wade H. , Youngblood Kelly
Published: January 2020

Picosecond-scale laser–matter interactions using compound parabolic
concentrators have demonstrated strongly relativistic ponderomotive
effects with

∼

10

×

increase in x-ray source brightness,
positron production and multi-MeV proton acceleration versus flat
targets, using a marginally relativistic intensity laser.
Mid-infrared frequency comb from a ring quantum cascade laser
Authors: Meng Bo , Singleton Matthew , Shahmohammadi Mehran , Kapsalidis Filippos , Wang Ruijun , Beck Mattias , Faist Jérôme
Published: January 2020

The effect of spatial hole burning on mode proliferation has been shown both theoretically and experimentally to be important for frequency comb operation in quantum cascade lasers (QCLs). It is therefore of great interest to investigate the frequency comb operation from integrated ring cavities where this effect is absent. Here we report a mid-infrared quantum cascade laser based on a buried heterostructure ring cavity that exhibits unidirectional lasing with a frequency comb spectrum displaying a predominantly

s
e
c
h

2

profile over a bandwidth of

∼

10

−
1

. A single beat note with 3 dB linewidth of

<

900

H
z

was observed over the last 85% of the whole current dynamic range. To further verify the frequency comb operation, a multiheterodyne experiment was carried out using a standard Fabry–Pérot QCL comb as a reference laser. This measurement allowed the retrieval of the spectral phases, indicating an operation with strong amplitude modulation.
Time delays from one-photon transitions in the continuum
Authors: Fuchs Jaco , Douguet Nicolas , Donsa Stefan , Martin Fernando , Burgdörfer Joachim , Argenti Luca , Cattaneo Laura , Keller Ursula
Published: January 2020

Attosecond photoionization time delays reveal information about the
potential energy landscape that an outgoing electron wavepacket probes
upon ionization. In this study, we experimentally quantify the
dependence of the time delay on the angular momentum of the liberated
photoelectrons. For this purpose, we resolved electron quantum-path
interference spectra in energy and angle using a two-color attosecond
pump–probe photoionization experiment in helium. A fitting procedure
of the angle-dependent interference pattern allows us to disentangle
the relative phase of all four quantum pathways that are known to
contribute to the final photoelectron signal. In particular, we
resolve the dependence on angular momentum of the delay of one-photon
transitions between continuum states, which is an essential and
universal contribution to the total photoionization delay observed in
attosecond pump–probe measurements. For such continuum–continuum
transitions, we measure a delay between outgoing

s

and

d

electrons as large as 12 attoseconds,
close to the ionization threshold in helium. Both
single-active-electron and first-principles ab
initio simulations confirm this observation for helium and
hydrogen, demonstrating the universality of the observed delays.
Ultraviolet-to-millimeter-band supercontinua driven by ultrashort mid-infrared laser pulses
Authors: Mitrofanov A. V. , Sidorov-Biryukov D. A. , Nazarov M. M. , Voronin A. A. , Rozhko M. V. , Shutov A. D. , Ryabchuk S. V. , Serebryannikov E. E. , Fedotov A. B. , Zheltikov A. M.
Published: January 2020

Combined optical nonlinearity of bound and free electrons in a fast-ionizing medium driven by ultrashort, mid-infrared (mid-IR) pulses gives rise to a vast variety of ultrafast nonlinear-optical scenarios, producing bright, broadband radiation in spectral ranges as different as ultraviolet (UV) and terahertz (THz). Given its enormous bandwidth, a quantitative experimental analysis of this type of nonlinear response is anything but simple. Here, we confront this challenge by ultrabroadband spectral measurements performed across the spectral range from the UV to the millimeter-wave (MMW) band jointly with beam profile analysis in the THz-to-MMW band and direct time-domain field waveform characterization. As one of the most striking results, the nonlinear response of a fast-ionizing gas driven by a two-color field, consisting of a high-peak-power sub-100-fs mid-IR pulse and its second harmonic, is shown to provide a source of a bright multiband supercontinuum (SC) radiation, whose spectrum spans over about 14 octaves, stretching from below 300 nm all the way beyond 4.3 mm. The MMW-to-THz part of this SC is emitted, as direct measurements show, in the form of half-cycle field waveforms that can be focused to yield a field strength of≈5MV/cm. At least 1.5% of the MMW–THz supercontinuum energy is emitted in the MMW range, giving rise to MMW field strengths up to 100 kV/cm in the beam waist region.
Sensorless-BLDC motor speed control with ensemble Kalman filter and neural network
Authors: Rif'an Muhammad , Yusivar Feri , Kusumoputro Benyamin
Published: January 2020

The use of sensorless technology at BLDC is mainly to improve operational reliability and play a role for wider use of BLDC motors in the future. This research aims to predict load changes and to improve the accuracy of estimation results of sensorless-BLDC. In this paper, a new filtering algorithm is proposed for sensorless brushless DC motor based on Ensemble Kalman filter (EnKF) and neural network. The proposed EnKF algorithm is used to estimate speed and rotor position, while neural network is used to estimate the disturbance by simulation. The proposed algorithm requires only the terminal voltage and the current of three phases for estimated speed and disturbance. A model of non-linear systems is carried out for simulation. Variations in disturbances such as external mechanical loads are given for testing the performance of the proposed algorithm. The experimental results show that the proposed algorithm has sufficient control with error speed of 3 % in a disturbance of 50 % of the rated-torque. Simulation results show that the speed can be tracked and adjusted accordingly either by disturbances or the presence of disturbances.
Exhaust emissions analysis of gasoline motor fueled with corncob-based bioethanol and RON 90 fuel mixture
Authors: Widiyanti Widiyanti , Mizar Muhammad Alfian , Wicaksana Christian Asri , Nurhadi Didik , Moses Kriya Mateeke
Published: January 2020

One of the viable solutions to the fossil fuel energy crisis was to seek alternative sources of environmentally friendly energy with the same or better quality such as bioethanol. It was possible to produce bioethanol from organic waste, e.g., corncob. This research aimed to obtain the lowest exhaust emission levels of CO and CO2 generated from a gasoline motor that used a mixture of bioethanol containing 96 % corncob and RON 90 fuel. This research was experimental using Anova statistical data analysis method. The results showed that the lowest average of CO emissions was 0.177 vol% using E100 fuel, and the highest average was 2.649 vol% using 100 % RON 90 fuel, displaying a significant difference. The lowest average of CO2 emissions was 6.6 vol% using E100 fuel, and the highest was 7.51 vol% using 100 % RON 90 fuel, which was insignificantly different. The mixture variation with the lowest CO and CO2 emissions was E100.
Quasi-flat linear PM generator optimization using simulated annealing algorithm for WEC in Indonesia
Authors: Azhari Budi , Wijaya Fransisco Danang
Published: January 2020

Linear permanent magnet generator (LPMG) is an essential component in recent wave energy converter (WEC) which exploits wave’s heave motion. It could be classified into tubular-type, flat-tricore type, and quasi-flat type. In previous researches, these three models have been studied and designed for pico-scale WEC. Design optimization has further been conducted for flat-tricore LPMG, by using simulated annealing (SA) algorithm. It modified some parameters to minimize the resulted copper loss. This paper aims to optimize a quasi-flat LPMG design by applying SA algorithm. The algorithm would readjust the initial LPMG parts dimension. Then, the output of the optimized design would be analyzed and compared. The results showed that the optimization could reduce the copper loss by up to 73.64 % and increase the efficiency from 83.2 % to 95.57 %. For various load resistances, the optimized design also produces larger efficiency. However, the optimized design has a larger size and produces larger cogging force than the initial design.
Smart grid photovoltaic system pilot scale using sunlight intensity and state of charge (SoC) battery based on Mamdani fuzzy logic control
Authors: Faqih Kamil , Primadi Wahyu , Handayani Anik Nur , Priharta Ari , Arai Kohei
Published: January 2020

The Utilization of renewable energy such as a photovoltaic system is the foremost alternative in transfers generated by conventional power plants, but the lack of photovoltaics is support for light intensity. The purpose of this research is to develop a pilot-scale smart grid photovoltaic system that can regulate the supply of electrical energy from either the battery or the power supply. The control system in this study uses the Mamdani fuzzy logic method in determining automatic system performance. This system monitors the intensity of light and battery which are then used as automatic safety parameters on the power supply, battery, and photovoltaic. The results of this study display the indicator results from the microcontroller in supplying electrical energy for the use of electrical loads, Power Supply has been served the load when the battery is in a low state which have a voltage `11 Volts, the battery has been served the load when the condition of the battery is in a medium and high condition which has a voltage of 11.5 `; ....; `13 Volts. PV has been served batteries or loads when the light intensity is cloudy and bright which have a light intensity of 3585 `; ...; `10752 Lux. This system can reduce dependence on conventional energy without reducing the quality of the energy supply at load and Photovoltaic system dependence on light intensity does not affect the supply of energy consumption to electrical loads.
Vehicular networking and computer vision-based distance estimation for VANET application using Raspberry Pi 3
Authors: Pratama Mulia , Gruosso Giambattista , Santoso Widodo Budi , Praptijanto Achmad
Published: January 2020

This research was implementing vehicle networking using WIFI connection and computer vision to measure the distance of vehicles in front of a driver. In particular, this works aimed to improve a safe driving environment thus supporting the current technology concept being developed for inter-vehicular networking, VANET, especially in its safety application such as Overtaking Assistance System. Moreover, it can wirelessly share useful visual information such as hazard area of a road accident. In accordance with Vehicle-to-Vehicle (V2V) concept, a vehicle required to be able to conduct networking via a wireless connection. Useful data and video were the objects to be sent over the network established. The distance of a vehicle to other vehicles towards it is measured and sent via WIFI together with a video stream of the scenery experienced by the front vehicle. Haar Cascade Classifier is chosen to perform the detection. For distance estimation, at least three methods have been compared in this research and found evidence that, for measuring 5 meters, the iterative methods shows 5.80. This method performs well up to 15 meters. For measuring 20 meters, P3P method shows a better result with only 0.71 meters to the ground truth. To provide a physical implementation for both the detection and distance estimation mechanism, those methods were applied in a compact small-sized vehicle-friendly computer device the Raspberry Pi. The performance of the built system then analyzed in terms of streaming latency and accuracy of distance estimation and shows a good result in measuring distance up to 20 meters.
Performance Evaluation of A2-A4-RSRQ and A3-RSRP Handover Algorithms in LTE Network
Authors: Hendrawan Hendrawan , Zain Ayu Rosyida , Lestari Sri
Published: January 2020

In LTE Network, users can move freely in the network through fast and seamless handover (HO). This research focuses on intra-LTE handover which occurs using interface X2 to move an EU between two eNBs, i.e. source eNB and target eNB without any changes in MME and SGW at EPC level. Two popular algorithms of intra-LTE handover namely A2-A4-RSRQ and A3-RSRP were evaluated and compared through simulations as well as direct measurements in the field. Simulation is conducted using NS3 simulation tool where performances of various scenarios from both algorithms were evaluated. The performance metrics studied include the average number of HOs that occur, throughput and optimized ratio. Simulations carried out for various scenarios in term of EU numbers, user speeds, and channel conditions. In addition, the results of one-month measurement of three eNBs were also presented. The measurement results are then compared and used to verify the simulation results. Furthermore, by using the optimizing ratio metric, the optimal pair of parameter values of Threshold as well as Offset and Handover Margin (HOM) along with Time-to-Trigger (TTT) are sought for the A2-A4-RSRQ and A3-RSRP respectively.
Programmable Syringe Pump for Selective Micro Droplet Deposition
Authors: Kurniawan Erry Dwi , Adam Alwin , Salik Muhammad Ichlasul , Gareso Paulus Lobo
Published: January 2020

Micro/nanopatterns with micro deposition techniques have been used in various applications such as flexible electronic devices, biosensing, and biological tissue engineering. For depositing a small size of droplets that can be controlled, structured and patterned precisely is a very important process for microfabrication. In this study, we developed a low cost and simple system for fabricating micro/nanostructure by a selective micro deposition process using a syringe pump. This method is an additive fabrication method where selective droplet materials are released through a needle of the syringe pump. By translating the rotating stepper motor into a linear movement of the lead screw, it will press the plunger of the syringe and give a force to the fluid inside the syringe, hence a droplet can be injected out. The syringe pump system consists of a syringe, the mechanical unit, and the controller unit. A stepper motor, the lead screw, and the mechanical components are used for the mechanical unit. Arduino Uno microcontroller is used as the controller unit and can be programmed by the computer through GUI (Graphical User Interface). The input parameters, such as the push or pull of flow direction, flow rate, the droplet volume, and syringe size dimension can be inputted by the user as their desired value via keypad or the computer. The measurement results show that the syringe pump has characteristics: the maximum average error value of the measured volume is 2.5% and the maximum average error value of the measured flow rate is 14%. The benefits of a syringe pump for micro deposition can overcome photolithography weaknesses, which require an etching and stencil process in the manufacture of semiconductors. Combining two or more syringes into one system with different droplet materials can be used as a promising method for 3D microfabrication in the future.
Pharmacological treatment strategies for neonates with patent ductus arteriosus: a systematic review
Authors: Yausep Oliver Emmanuel , Iskandar Adhi Teguh Perma
Published: January 2020

Background Patent ductus arteriosus (PDA) has a variety of treatment options, ranging from pharmacologic, with nonsteroidal anti-inflammatory drugs (NSAIDs) as first line therapy, to surgical ligation. However, treatment with NSAIDs is associated with severe side effects as well as many contraindications. Paracetamol is a non-classic NSAID with the prospect of fewer side effects compared to other NSAID counterparts.

Objectives To compare the efficacy and safety of paracetamol to ibuprofen or indomethacin for neonates with PDA by systematic review of the literature.

Methods Our literature search was conducted on four databases: PubMed, Scopus, Ovid, and The Cochrane Library, to find studies that compared paracetamol to ibuprofen or indomethacin in neonates with PDA. Articles were selected based on pre-set eligibility criteria. Outcomes extracted from each study included PDA closure rates as well as adverse events rates.

Results Seven randomized controlled trials (RCTs) were included in this study. Five compared paracetamol to ibuprofen and one used indomethacin as a control. The studies were of good quality, with several variations in methodology. All trials reported similar closure rates of paracetamol compared to ibuprofen or indomethacin. Three studies reported similar rates of adverse events, whereas another three reported safety profiles that favoured paracetamol over ibuprofen.

Conclusion Paracetamol has similar efficacy to ibuprofen and indomethacin with regards to rate of PDA closure following a course of treatment. Paracetamol is also reportedly relatively safe in terms of adverse events rates experienced by patients.