bluuebunny/crossref_metadata_2025 huggingface dataset:
CaV1.3 L-type Ca2+ channel modulates pancreatic β-cell electrical activity and survival
Authors: Theiner Tamara , Jacobo-Piqueras Noelia , Ortner Nadine J. , Geisler Stefanie M. , Tuluc Petronel
Published: November 2021

Pancreatic β cells express several high voltage-gated Ca2+ channel (HVCC) isoforms critical for insulin release, cell differentiation, and survival. RNaseq and qPCR analyses demonstrated that CACNA1D gene encoding for CaV1.3-α1D isoform is highly expressed in pancreatic islets of both mice and men. Additionally, CACNA1D genetic polymorphisms were associated with increased susceptibility for diabetes while CaV1.3 gain-of-function mutations cause hyperinsulinemia in humans. Nevertheless, functional evidence for the role of CaV1.3 on β-cell electrical activity, insulin release, and β-cell mass is contradictory and largely unknown. Here, we show that CaV1.3 deletion led to a sixfold increase in DNA damage and a threefold decrease in proliferation markers in pancreatic β cells of 14-d-old mice, while adult mice were largely unaffected. However, β-cell mass was reduced by ∼20% in both young and old mice, resulting in a diminished sustained insulin release. Voltage-clamp recordings in β-cells of 14-d-old mice showed an ∼20% reduction in total Ca2+ influx (WT Ipeak = −19.76 ± 1.04 pA/pF; CaV1.3−/− Ipeak = −14.84 ± 0.61 pA/pF, P = 0.001) accompanied by slower inactivation and an ∼5 mV rightwards shift in the voltage dependence of activation (WT V1/2 = −7.71 ± 0.82 mV; CaV1.3−/− V1/2 = −2.32 ± 1.09 mV, P = 0.0003). Although to a lower extent, Ca2+ influx in adult CaV1.3−/− β cells was similarly affected. Moreover, current-clamp recordings showed that CaV1.3 deletion delayed the glucose-induced action potential (AP) onset, reduced AP firing frequency (e.g., at 7.5 mM glucose, WT = 4.3 Hz; CaV1.3−/− = 2.1 Hz, P = 0.001) and AP-train frequency (e.g., at 7.5 mM glucose intertrain interval, WT = 49.3 ± 9.6 s; CaV1.3−/− = 120.3 ± 25.5 s, P = 0.04) in both young and adult β cells. Therefore, our data demonstrate that the CaV1.3 channel is required for the initiation of glucose-induced β-cell electrical activity and modulates β-cell mass and insulin release in both young and old mice.
Production of 87Rb Bose-Einstein Condensate in an Asymmetric Crossed Optical Dipole Trap
Authors: Ma Zhu , Han Chengyin , Jiang Xunda , Fang Ruihuan , Qiu Yuxiang , Zhao Minhua , Huang Jiahao , Lu Bo , Lee Chaohong
Published: November 2021

We report the production of 87Rb Bose–Einstein condensate in an asymmetric crossed optical dipole trap (ACODT) without the need of an additional dimple laser. In our experiment, the ACODT is formed by two laser beams with different radii to achieve efficient capture and rapid evaporation of laser cooled atoms. Compared to the cooling procedure in a magnetic trap, the atoms are firstly laser cooled and then directly loaded into an ACODT without the pre-evaporative cooling process. In order to determine the optimal parameters for evaporation cooling, we optimize the power ratio of the two beams and the evaporation time to maximize the final atom number left in the ACODT. By loading about 6 × 105 laser cooled atoms in the ACODT, we obtain a pure Bose–Einstein condensate with about 1.4 × 104 atoms after 19 s evaporation. Additionally, we demonstrate that the fringe-type noises in optical density distributions can be reduced via principal component analysis, which correspondingly improves the reliability of temperature measurement.
Charge Density Wave and Electron-Phonon Interaction in Epitaxial Monolayer NbSe2 Films
Authors: Xie Xuedong , Lin Dongjing , Zhu Li , Li Qiyuan , Zong Junyu , Chen Wang , Meng Qinghao , Tian Qichao , Li Shao-Chun , Xi Xiaoxiang , Wang Can , Zhang Yi
Published: November 2021

Understanding the interplay between superconductivity and charge-density wave (CDW) in NbSe2 is vital for both fundamental physics and future device applications. Here, combining scanning tunneling microscopy, angle-resolved photoemission spectroscopy and Raman spectroscopy, we study the CDW phase in the monolayer NbSe2 films grown on various substrates of bilayer graphene (BLG), SrTiO3(111), and Al2O3(0001). It is found that the two stable CDW states of monolayer NbSe2 can coexist on NbSe2/BLG surface at liquid-nitrogen temperature. For the NbSe2/SrTiO3(111) sample, the unidirectional CDW regions own the kinks at ±41 meV and a wider gap at 4.2 K. It is revealed that the charge transfer from the substrates to the grown films will influence the configurations of the Fermi surface, and induce a 130 meV lift-up of the Fermi level with a shrink of the Fermi pockets in NbSe2/SrTiO3(111) compared with the NbSe2/BLG. Combining the temperature-dependent Raman experiments, we suggest that the electron-phonon coupling in monolayer NbSe2 dominates its CDW phase transition.
The 4f-Hybridization Strength in Ce
m

Mn
In3m+2n
Heavy-Fermion Compounds Studied by Angle-Resolved Photoemission Spectroscopy
Authors: Song Jiao-Jiao , Luo Yang , Zhang Chen , Wu Qi-Yi , Durakiewicz Tomasz , Sassa Yasmine , Tjernberg Oscar , Månsson Martin , Berntsen Magnus H. , Zhao Yin-Zou , Liu Hao , Zhu Shuang-Xing , Liu Zi-Teng , Wu Fan-Ying , Liu Shu-Yu , Bauer Eric D. , Rusz Ján , Oppeneer Peter M. , Yuan Ya-Hua , Duan Yu-Xia , Meng Jian-Qiao
Published: November 2021

We systemically investigate the nature of Ce 4f electrons in structurally layered heavy-fermion compounds Ce
m

M

n
In3m + 2n
(with M = Co, Rh, Ir, and Pt, m = 1, 2, n = 0–2), at low temperature using on-resonance angle-resolved photoemission spectroscopy. Three heavy quasiparticle bands f
0,

f

7
/
2

1

and

f

5
/
2

1

, are observed in all compounds, whereas their intensities and energy locations vary greatly with materials. The strong f
0 states imply that the localized electron behavior dominates the Ce 4f states. The Ce 4f electrons are partially hybridized with the conduction electrons, making them have the dual nature of localization and itinerancy. Our quantitative comparison reveals that the

f

5
/
2

1

–f
0 intensity ratio is more suitable to reflect the 4f-state hybridization strength.
Photoemission Spectroscopic Evidence of Multiple Dirac Cones in Superconducting BaSn3
Authors: Huang Zhe , Shi Xianbiao , Zhang Gaoning , Liu Zhengtai , Cho Soohyun , Jiang Zhicheng , Liu Zhonghao , Liu Jishan , Yang Yichen , Xia Wei , Zhao Weiwei , Guo Yanfeng , Shen Dawei
Published: November 2021

Signatures of topological superconductivity (TSC) in superconducting materials with topological nontrivial states prompt intensive researches recently. Utilizing high-resolution angle-resolved photoemission spectroscopy and first-principles calculations, we demonstrate multiple Dirac fermions and surface states in superconductor BaSn3 with a critical transition temperature of about 4.4 K. We predict and then unveil the existence of two pairs of type-I topological Dirac fermions residing on the rotational axis. Type-II Dirac fermions protected by screw axis are confirmed in the same compound. Further calculation for the spin helical texture of the observed surface states originating from the Dirac fermions gives an opportunity for realization of TSC in one single material. Hosting multiple Dirac fermions and topological surface states, the intrinsic superconductor BaSn3 is expected to be a new platform for further investigation of topological quantum materials as well as TSC.
Detection of Magnetic Gap in Topological Surface States of MnBi2Te4
Authors: Ji Hao-Ran , Liu Yan-Zhao , Wang He , Luo Jia-Wei , Li Jia-Heng , Li Hao , Wu Yang , Xu Yong , Wang Jian
Published: November 2021

Recently, intrinsic antiferromagnetic topological insulator MnBi2Te4 has drawn intense research interest and leads to plenty of significant progress in physics and materials science by hosting quantum anomalous Hall effect, axion insulator state, and other quantum phases. An essential ingredient to realize these quantum states is the magnetic gap in the topological surface states induced by the out-of-plane ferromagnetism on the surface of MnBi2Te4. However, the experimental observations of the surface gap remain controversial. Here, we report the observation of the surface gap via the point contact tunneling spectroscopy. In agreement with theoretical calculations, the gap size is around 50 meV, which vanishes as the sample becomes paramagnetic with increasing temperature. The magnetoresistance hysteresis is detected through the point contact junction on the sample surface with an out-of-plane magnetic field, substantiating the surface ferromagnetism. Furthermore, the non-zero transport spin polarization coming from the ferromagnetism is determined by the point contact Andreev reflection spectroscopy. Combining these results, the magnetism-induced gap in topological surface states of MnBi2Te4 is revealed.
Updated Progresses in Perovskite Solar Cells
Authors: Qu Zihan , Ma Fei , Zhao Yang , Chu Xinbo , Yu Shiqi , You Jingbi
Published: November 2021

In the last decade, perovskite solar cells (PSCs) have greatly drawn researchers’ attention, with the power conversion efficiency surging from 3.8% to 25.5%. PSCs possess the merits of low cost, simple fabrication process and high performance, which could be one of the most promising photovoltaic technologies in the future. In this review, we focus on the summary of the updated progresses in single junction PSCs including efficiency, stability and large area module. Then, the important progresses in tandem solar cells are briefly discussed. A prospect into the future of the field is also included.
Asymptotic structure with a positive cosmological constant
Authors: Fernández-Álvarez Francisco , Senovilla José M M
Published: November 2021

This is the second of two papers (Fernández-Álvarez F and Senovilla J M M 2021 Class. Quantum Grav.
39 165011) that study the asymptotic structure of space–times with a non-negative cosmological constant Λ. This paper deals with the case Λ > 0. Our approach is founded on the ‘tidal energies’ built with the Weyl curvature and, specifically, we use the asymptotic super-Poynting vector computed from the rescaled Bel–Robinson tensor at infinity to provide a covariant, gauge-invariant, criterion for the existence, or absence, of gravitational radiation at infinity. The fundamental idea we put forward is that the physical asymptotic properties are encoded in

(

J
,

h

a
b

,

D

a
b

)

, where the first element of the triplet is a three-dimensional manifold, the second is a representative of a conformal class of Riemannian metrics on

J

, and the third element is a traceless symmetric tensor field on

J

. The full set of physically relevant properties of the space–time cannot be characterised at infinity without taking D

ab
into consideration, and our radiation criterion takes this fully into account. We similarly propose a no-incoming radiation criterion based also on the triplet

(

J
,

h

a
b

,

D

a
b

)

and on radiant supermomenta deduced from the rescaled Bel–Robinson tensor too. We search for news tensors encoding the two degrees of freedom of gravitational radiation and argue that any news-like object must be associated to, and depends on, two-dimensional cross-sections of

J

. We identify one component of news for every such cross-section and present a general strategy to find the second component, which depends on the particular physical situation. We put in connection the radiation condition and the news-like tensors with the directional structure of the gravitational field at infinity and the criterion of no-incoming radiation. We also introduce the concept of equipped

J

by endowing the conformal boundary with a selected congruence of curves which may be determined by the algebraic structure of the asymptotic Weyl tensor. We also define a group of asymptotic symmetries preserving the new structures. We consider the limit Λ → 0, and apply all our results to selected exact solutions of Einstein field equations in order to illustrate their validity.
Transfer learning method for rolling bearing fault diagnosis under different working conditions based on CycleGAN
Authors: Zhao Jiantong , Huang Wentao
Published: November 2021

In practical bearing fault diagnosis tasks, the available labeled data are often not from the equipment to be diagnosed and cannot cover all manner of working conditions. The adopted data-driven method is required to have a certain degree of cross-domain and cross-working condition transfer learning diagnosis ability. However, limited by the performance of existing transfer learning methods, the potential difference between the source domain and the target domain poses a challenge for the accuracy of transfer diagnosis. In this paper, a cross-working condition data supplement method based on the cycle generative adversarial network (CycleGAN) and a dynamics model is proposed, which can use limited available data to approximate the missing parts of existing data and be used for diagnosis of the target domain. First, we considered the limited experimental data as the target domain, the simulation data corresponding to the working condition as the source domain and used the working condition as the benchmark to constrain the data correspondence between the two datasets. We then used the CycleGAN model to learn the feature mapping from simulation to experiment. Second, based on the working condition of the data to be tested, the corresponding simulation data were input into the trained generator to obtain labeled data with experimental characteristics under the corresponding working conditions, and transferred the dataset as the source domain data to the data to be tested. In the test using self-made simulation and experimental datasets, combined with the transfer learning method based on the probability distribution adaptation, it was shown that the proposed method could effectively improve the diagnostic impact of the single transfer learning method in cross-domain and cross-working conditions when the working condition span was large.
Ultrathin structure of oxygen doped carbon nitride for efficient CO2 photocatalytic reduction
Authors: Zhong Kang , Zhu Xingwang , Yang Jinman , Mo Zhao , Qian Junchao , He Minqiang , Song Yanhua , Liu Jinyuan , Chen Hanxiang , Li Huaming , Xu Hui
Published: November 2021

Photocatalytic conversion of carbon dioxide into fuels and valuable chemicals is a promising method for carbon neutralization and solving environmental problems. Through a simple thermal-oxidative exfoliation method, the O element was doped while exfoliated bulk g-C3N4 into ultrathin structure g-C3N4. Benefitting from the ultrathin structure of g-C3N4, the larger surface area and shorter electrons migration distance effectively improve the CO2 reduction efficiency. In addition, density functional thory computation proves that O element doping introduces new impurity energy levels, which making electrons easier to be excited. The prepared photocatalyst reduction of CO2 to CO (116 μmol g−1 h−1) and CH4 (47 μmol g−1 h−1).
Flexible synthesis of high-performance electrode materials of N-doped carbon coating MnO nanowires for supercapacitors
Authors: Zhou Ting , Zhang Wenjun , Fu Hao , Fang Jingyuan , Chen Chunnian , Wang Zhongbing
Published: November 2021

The MnO/C composites were obtained by co-precipitation method, which used Mn3O4 nanomaterials as precursors and dopamine solution after ultrasonic mixing and calcination under N2 atmosphere at different temperatures. By studying the difference of MnO/C nanomaterials formed at different temperatures, it was found that with the increase of calcination temperature, the materials appear obvious agglomeration. The optimal calcination temperature is 400 °C, and the resulting MnO/C is a uniformly dispersed slender nanowire structure. The specific capacitance of MnO/C nanowires can reach 356 F g−1 at 1 A g−1. In the meantime, the initial capacitance of MnO/C nanowires remains 106% after 5000 cycles. Moreover, the asymmetric supercapacitor was installed, which displays a tremendous energy density of 30.944 Wh kg−1 along with a high power density of 10 kW kg−1. The composite material reveals a promising prospect in the application of supercapacitors.
Efficient knowledge distillation for liver CT segmentation using growing assistant network
Authors: Xu Pengcheng , Kim Kyungsang , Koh Jeongwan , Wu Dufan , Rim Lee Yu , Young Park Soo , Young Tak Won , Liu Huafeng , Li Quanzheng
Published: November 2021

Segmentation has been widely used in diagnosis, lesion detection, and surgery planning. Although deep learning (DL)-based segmentation methods currently outperform traditional methods, most DL-based segmentation models are computationally expensive and memory inefficient, which are not suitable for the intervention of liver surgery. To address this issue, a simple solution is to make a segmentation model very small for the fast inference time, however, there is a trade-off between the model size and performance. In this paper, we propose a DL-based real-time 3-D liver CT segmentation method, where knowledge distillation (KD) method, known as knowledge transfer from teacher to student models, is incorporated to compress the model while preserving the performance. Because it is well known that the knowledge transfer is inefficient when the disparity of teacher and student model sizes is large, we propose a growing teacher assistant network (GTAN) to gradually learn the knowledge without extra computational cost, which can efficiently transfer knowledge even with the large gap of teacher and student model sizes. In our results, dice similarity coefficient of the student model with KD improved 1.2% (85.9% to 87.1%) compared to the student model without KD, which is a similar performance of the teacher model using only 8% (100k) parameters. Furthermore, with a student model of 2% (30k) parameters, the proposed model using the GTAN improved the dice coefficient about 2% compared to the student model without KD, and the inference time is 13 ms per a 3-D image. Therefore, the proposed method has a great potential for intervention in liver surgery as well as in many real-time applications.
Heavy impurity transport in tokamaks subject to plasma rotation, NTV and the influence of saturated ideal MHD perturbations
Authors: Lascas Neto E , Graves J P , Raghunathan M , Sommariva C , Pfefferlé D ,   JET Contributors
Published: November 2021

Strongly peaked tungsten accumulation is a common feature of high performance plasma scenarios in JET with the ITER-like wall, particularly during MHD activity induced by

m

/

n
=
1

/

1

continuous modes. This study investigates the effect of

1

/

1

long living internal kink modes on heavy impurity transport in the presence of strong flows and NTV ambipolar electric field. A novel formulation which includes these effects is presented and applied in the VENUS-LEVIS code in order to follow tungsten ions in a saturated JET-like

1

/

1

internal kinked toroidally rotating plasma configuration. The synergy between 3D magnetic fields, strong flows and NTV is seen to cause tungsten accumulation in contrast to what is observed in similar axisymmetric configurations. Rapid inward transport of impurities in JET plasmas following the triggering of continuous

1

/

1

modes is explained by the work presented here, and we use the same theory to postulate why outward transport can occur in kinked ASDEX-U plasmas.
Impurity transport studies at the HSX stellarator using active and passive CVI spectroscopy
Authors: Swee C , Geiger B , Dux R , Kumar S T A , Castillo J F , Bader A , Gerard M
Published: November 2021

The transport of carbon impurities has been studied in the helically symmetric stellarator experiment (HSX) using active and passive charge exchange recombination spectroscopy (CHERS). For the analysis of the CHERS signals, the STRAHL impurity transport code has been re-written in the python programming language and optimized for the application in stellarators. In addition, neutral hydrogen densities both along the NBI line of sight as well as for the background plasma have been calculated using the FIDASIM code. By using the basinhopping algorithm to minimize the difference between experimental and predicted active and passive signals, significant levels of impurity diffusion are observed. Comparisons with neoclassical calculations from DKES/PENTA show that the inferred levels exceed the neoclassical transport by about a factor of four in the core and more than 100 times towards the plasma edge, thus indicating a high level of anomalous transport. This observation is in agreement with experimental heat diffusivites determined from a power balance analysis which exhibits strong anomalous transport as well.
Recent progress in red light-emitting diodes by III-nitride materials
Authors: Iida Daisuke , Ohkawa Kazuhiro
Published: November 2021

GaN-based light-emitting devices have the potential to realize all visible emissions with the same material system. These emitters are expected to be next-generation red, green, and blue displays and illumination tools. These emitting devices have been realized with highly efficient blue and green light-emitting diodes (LEDs) and laser diodes. Extending them to longer wavelength emissions remains challenging from an efficiency perspective. In the emerging research field of micro-LED displays, III-nitride red LEDs are in high demand to establish highly efficient devices like conventional blue and green systems. In this review, we describe fundamental issues in the development of red LEDs by III-nitrides. We also focus on the key role of growth techniques such as higher temperature growth, strain engineering, nanostructures, and Eu doping. The recent progress and prospect of developing III-nitride-based red light-emitting devices will be presented.
Influence of disorder strength on the superconducting mechanism of MgB2
Authors: Lee Jung Min , Jung Soon-Gil , Han Yoonseok , Park Tae-Ho , Jang Jaekyung , Jeon Hye-ran , Yeo Sunmog , Choi Han-Yong , Park Tuson , Kang Won Nam
Published: November 2021

We investigate the effect of disorder on the superconducting mechanism of MgB2 thin films using low-energy ion irradiation. The c-axis lattice constant and T
c of MgB2 thin films change systematically as the magnitude of disorder, which corresponds to the value of average displacements per atom (dpa
avg), increases. Here, dpa
avg is controlled by the amount of irradiated ions. The dpa
avg dependence of the electron–phonon coupling constants (λ) is estimated using the McMillan equation. For dpa
avg ⩽ 0.049, λ is linearly proportional to dpa
avg. On the other hand, for dpa
avg > 0.049, the T
c of the disordered MgB2 deviates from the linear fitting curve, and insulating behavior is observed in the normal state resistivity. These results indicate that the superconducting mechanism of MgB2 can be changed by the electronic system caused by disorder strength affecting the electron–phonon coupling constant λ.
Screening current induced magnetic field and stress in ultra-high-field magnets using REBCO coated conductors
Authors: Yan Yufan , Li Yi , Qu Timing
Published: November 2021

Rare-earth-based barium copper oxide (REBCO) coated conductors are promising candidates for the development of ultra-high-field (UHF) magnets, due to its high in-field performance, engineering current density, tensile strength and commercial availability. However, technological challenges pertaining to the large screening currents still remain. The major issues caused by the screening currents in REBCO conductors in UHF applications involve two aspects: the screening current induced magnetic field (SCF), and the screening current induced stress (SCS). In the past decades, extensive research has been devoted to the SCF, offering a variety of possible remedies. With latest advances in the construction and testing of UHF magnets, new observations of the SCF involving REBCO coils were reported. The SCS was identified in recent years and has raised growing concerns. The excessive and highly concentrated Lorentz force, rooted in the high magnetic field and the screening currents, poses threats to the mechanical strength of REBCO coated conductors. The aim of this paper is to review recent research efforts in understanding and tackling the screening current related technological issues. For the SCF, we focus on the latest observations in high-field experiments and its various mitigation methods. For the SCS, we present recent studies including experimental characterizations, numerical modelling and possible countermeasures. It is still an open question to precisely predict the SCS in large-scale HTS magnets. How to minimize the influence of SCF and SCS is one of the key technical challenges for the design of future UHF magnets.
Mixed-mode oscillations for slow-fast perturbed systems
Authors: Liu Yaru , Liu Shenquan , Lu Bo , Kurths Jürgen
Published: November 2021

This article concerns the dynamics of mixed-mode oscillations (MMOs) emerging from the calcium-based inner hair cells (IHCs) model in the auditory cortex. The paper captures the MMOs generation mechanism based on the geometric singular perturbation theory (GSPT) after exploiting the average analysis for reducing the full model. Our analysis also finds that the critical manifold and folded surface are central to the mechanism of the existence of MMOs at the folded saddle for the perturbed system. The system parameters, such like the maximal calcium channels conductance, controls the firing patterns, and many new oscillations occur for the IHCs model. Tentatively, we conduct dynamic analysis combined with dynamic method based on GSPT by giving slow-fast analysis for the singular perturbed models and bifurcation analysis. In particular, we explore the two-slow-two-fast and three-slow-one-fast IHCs perturbed systems with layer and reduced problems so that differential-algebraic equations are obtained. This paper reveals the underlying dynamic properties of perturbed systems under singular perturbation theory.
An on-chip integrated microfiber–silicon–graphene hybrid structure photodetector
Authors: Wang Fangjie , Chen Xiaoxu , Zhou Sikun , Gu Qiongqiong , Zhou Hao , Deng Guoliang , Zhou Shouhuan
Published: November 2021

Silicon photonic devices have great potential for photocommunication, and silicon-based photodetectors have attracted wide attention. Here, we report an on-chip integrated microfiber–silicon–graphene hybrid structure photodetector that can operate in the visible and near-infrared ranges. The detector has a responsivity of ∼136 mA W−1 at 808 nm and a rise time of ∼1.1 μs. At a reverse bias of 5 V, we achieved a responsivity of ∼1350 mA W−1. Our device provides an option for on-chip integration.
Investigation of defective hybrid cladding with silicon nanocrystal PCF for supercontinuum generation
Authors: Rajesh A , Chandru S , Robinson S
Published: November 2021

Defective hybrid cladding through a silicon nanocrystal-core-structured photonic crystal fiber intended for high pump power supercontinuum proliferation is discussed in this paper. The cladding comprehends a hybrid approach of a hexagonal air hole in the outer section and a petal-structured air hole in the inner layer with a twisted pattern. Such a procedure with an air hole in the cladding section with a silicon nanocore displays high nonlinearity and negative dispersion at the communication window for varying pulse widths with 20 kW pump power. The impact of structural parameters of the proposed structure on the optical constraints is discussed, namely, dispersion, nonlinearity and group-velocity dispersion for wavelengths ranging from 0.45 µm to 1.85 µm. The proposed structure with optimized structural parameters provides high nonlinearity of about 6.38 × 106 W−1 km−1 with negative dispersion of −70.19 ps (nm km)−1 at 1550 nm.
Rejection sampling for Bayesian uncertainty evaluation using the Monte Carlo techniques of GUM-S1
Authors: Marschall Manuel , Wübbeler Gerd , Elster Clemens
Published: November 2021

Supplement 1 to the GUM (GUM-S1) extends the GUM uncertainty framework to non-linear functions and non-Gaussian distributions. For this purpose, it employs a Monte Carlo method that yields a probability density function for the measurand. This Monte Carlo method has been successfully applied in numerous applications throughout metrology. However, considerable criticism has been raised against the type A uncertainty evaluation of GUM-S1. Most of the criticism could be addressed by including prior information about the measurand which, however, is beyond the scope of GUM-S1. We propose an alternative Monte Carlo method that will allow prior information about the measurand to be included. The proposed method is based on a Bayesian uncertainty evaluation and applies a simple rejection sampling approach using the Monte Carlo techniques of GUM-S1. The range of applicability of the approach is explored theoretically and in terms of examples. The results are promising, leading us to conclude that many metrological applications could benefit from this approach. Software support is provided to ease its implementation.
Activation of retinal ganglion cells using a biomimetic artificial retina
Authors: Greco Jordan A , Wagner Nicole L , Jensen Ralph J , Lawrence Daniel B , Ranaghan Matthew J , Sandberg Megan N , Sandberg Daniel J , Birge Robert R
Published: November 2021

Objective. Biomimetic protein-based artificial retinas offer a new paradigm for restoring vision for patients blinded by retinal degeneration. Artificial retinas, comprised of an ion-permeable membrane and alternating layers of bacteriorhodopsin (BR) and a polycation binder, are assembled using layer-by-layer electrostatic adsorption. Upon light absorption, the oriented BR layers generate a unidirectional proton gradient. The main objective of this investigation is to demonstrate the ability of the ion-mediated subretinal artificial retina to activate retinal ganglion cells (RGCs) of degenerated retinal tissue. Approach. Ex vivo extracellular recording experiments with P23H line 1 rats are used to measure the response of RGCs following selective stimulation of our artificial retina using a pulsed light source. Single-unit recording is used to evaluate the efficiency and latency of activation, while a multielectrode array (MEA) is used to assess the spatial sensitivity of the artificial retina films. Main results. The activation efficiency of the artificial retina increases with increased incident light intensity and demonstrates an activation latency of ∼150 ms. The results suggest that the implant is most efficient with 200 BR layers and can stimulate the retina using light intensities comparable to indoor ambient light. Results from using an MEA show that activation is limited to the targeted receptive field. Significance. The results of this study establish potential effectiveness of using an ion-mediated artificial retina to restore vision for those with degenerative retinal diseases, including retinitis pigmentosa.
KOH Activation with Microwave Irradiation and its Effect on the Physical Properties of Orange Peel Activated Carbon
Authors: Awitdrus  , Siregar Gladys May Grace , Agustino  , Saktioto  , Iwantono  , Syahputra Romi Fadli , Farma Rakhmawati
Published: November 2021

Chemical activation with assisted microwave irradiation was used to produced activated carbon from orange peel waste. The activating agent was potassium hydroxide (KOH) with concentrations of 2 M, 3 M, and 4 M. The microwave irradiation was done for 15 minutes with a 630 Watt output power. KOH concentration affected the physical properties of OP-ACxM. With increasing KOH concentration, the interlayer spacing (d002
and d100
) grew, stack height (Lc
) increased, and stack width (La) dropped. The number of pores on the surface of OP-ACxM increased after the chemical activation process. In OP-ACxM, FTIR analysis reveals the presence of O-H, C-H, C-C, C=O, C=C, and C-O.
Application of biofertilizer and Local Beauveria bassiana Vuillemin on Growth, Production and Resistant of Red Chili Plants (Capsicum annuum L.)
Authors: Hapsoh  , Dini I R , Ulfah I.
Published: November 2021

The use of inorganic fertilizers and chemical pesticides in increasing chili production at high doses continuously can damage the environment and resistant to pests. The use of inorganic fertilizers and chemical pesticides can be minimized by environment friendly products. The research was conducted by combining the application of biofertilizers and local Beauveria bassiana to support the growth and production of environmentally friendly plants. This research was carried out experimentally arranged according to a Factorial Completely Randomized Design (CRD) with two factors. The first factor was the application of biofertilizer consisting of 4 levels, namely: zero applications of biofertilizer, one application at 24 DAP, two applications at 24 DAP and 54 DAP and three applications at 24 DAP, 54 DAP and 64 DAP. The second factor was the application of local B. bassiana consisting of 4 levels, namely: zero applications of local B. bassiana, one application at 24 DAP, two applications at 24 DAP and 54 DAP and three applications at 24 DAP, 54 DAP and 64 DAP. The parameters of research consisted plant height, dichotom height, flowering plant age, harvesting age, number of fruits per plant, fruit length, fruit weight, fruit weight per plant, leaf pest attack intensity and fruit pest attack intensity. The data from the analysis of variance were further tested with the DNMRT test at the 5% level. The result showed that no interaction between the application of biofertilizers and B. bassiana on the growth, yield and resistance of red chili plants. However, the combination of application of biofertilizer and B. bassiana three times gave good results on the growth, yield and resistance of red chili plants compared to the application of biofertilizer and B. bassiana zero times.
Trees and Bushes in the Bolshoi Uran River Basin (Orenburg Region)
Authors: Ryabinina Zinaida N. , Tabuldin Julay Z. , Markova Gulfiya A. , Anhalt Elena M. , Dobrodomova Larisa A. , Nikonova Elena A. , Kalyakina Railya G.
Published: November 2021

The article analyzes the tree and shrub flora of the B. Uran river basin. An inventory of the flora was carried out, characteristics were given according to floristic spectra (taxonomic, ecological, phytocenotic, etc.), and a list of plants was compiled. It is established that 42 wild species of trees and shrubs belonging to 15 families grow on the studied territory. The most common family is Rosaceae, the largest genera are Salix and Populus. The availability of moisture was determined by the predominance of mesophytic forest vegetation. The chorological analysis of the flora indicates a significant presence of adventitious wild-growing species. The analysis of the species structure of phytocenoses indicates an anthropogenic succession.
Creation of aerosolized detergent compositions for protecting high-precision metal mirrors from the impact of adverse climate factors
Authors: Filin S , Rogalin V , Kaplunov I
Published: November 2021

This article is devoted to creation of aerosolized detergent compositions, needful for use during operation of high-precision metal mirrors, as a rule, in field conditions. The created detergent compositions with inhibitory properties allow, simultaneously with carrying out the process of physicochemical cleaning of optical surface from technological impurities, to ensure its protection from the influence of adverse climatic factors during storage, transportation, installation and exploitation of the element with the possibility of its alignment. The high climatic resilience of the protective films investigated in this article, which are formed during the cleaning of the optical surface, is shown. In this case, the optical characteristics of the processed elements after climatic tests do not get worse.
System for neural network recognition of malignant pigmented skin neoplasms with image pre-processing
Authors: Lyakhova U A , Lyakhov P A , Abdulkadirov R I , Efimenko G A , Romanov S A , Kaplun D I
Published: November 2021

The article presents a system for the recognition of malignant pigmented skin neoplasms with a preliminary processing stage. Image pre-processing consists of removing hair structures from images, as well as resizing images and their further augmentation. Augmentation made it possible to increase the variety of training data, balance the number of images in different categories, and avoid retraining the neural network. The modeling was carried out using the MatLab R2020b software package for solving technical calculations on clinical dermatoscopic images from the international open archive ISIC Melanoma Project. The proposed system for the recognition of malignant pigmented skin neoplasms made it possible to increase the accuracy of image classification up to 80.55%. The use of the proposed recognition system will make it possible to increase the efficiency and quality of diagnosis, in comparison with the methods of visual diagnosis.
Alternative mechanisms of the primary act of gas-phase monomolecular thermal decomposition of N-methyl-N’-methoxydiazene-N-oxide according to the data of quantum chemical calculations
Authors: Nikolaeva E V , Khrapkovskii G M , Aristov I V , Egorov D L , Shamov A G
Published: November 2021

The mechanisms of the primary act of thermal decomposition of the simplest representative of the series of alkoxy-NNO-azoxy compounds – N-methyl-N’-methoxydiazene-N- oxide are studied using quantum-chemical density functional methods PBE, B3LYP, wB97XD with different sets of basic functions, as well as the composite G4 method. It is shown that the most probable channel of its thermal destruction, leading to the formation of experimentally observed reaction products, is isomerization because of rotation of the OCH3 group around the NO bond with the subsequent transfer of the CH3 group between oxygen atoms. In this case, the transfer of the CH3 group is the limiting reaction of the thermal decomposition of N-methyl-N’-methoxydiazene-N-oxide as a whole.
Polaritonic crystal formed of a tunnel-coupled microcavity array and an ensemble of quantum dots
Authors: Rumyantsev V V , Fedorov S A , Gumennyk K V , Rybalka A Ye , Zavorotnev Yu D
Published: November 2021

Propagation of polariton excitations in a defect-containing one-dimensional lattice of microcavities with embedded ultracold atomic nanoclusters (quantum dots) is being considered. The virtual crystal approximation is used to study the properties of electromagnetic excitation spectrum resulting from random variations of the atomic subsystem composition and positions of micropores, as well as from a homogeneous elastic deformation of the considered one-dimensional structure. The group velocity dependence of polariton excitations on structural defect concentration and on deformation parameter is being numerically modeled.
Theory of vector equations of electromagnetic wave diffraction on a rectilinear tubular cylinder
Authors: Sochilin A V , Eminov S I
Published: November 2021

The vector equation for the diffraction of electromagnetic waves on the surface of a rectilinear circular cylinder without ends with respect to surface currents is considered. As a result of transformations from the original equation, one-dimensional systems of integral equations are obtained. For all four integral operators describing the systems, the main parts are highlighted. Using the remarkable properties of one-dimensional diffraction operators, the Fredholm equation of the second kind in Sobolev spaces is obtained.
Thermodynamic functions of ibuprofen
Authors: Turovtsev V V , Emel’yanenko V N , Fedina Yu A , Orlov Yu D
Published: November 2021

A conformational analysis has been conducted, structures that make a significant contribution to properties are selected, and the partial thermodynamic functions of ibuprofen conformers are calculated. The temperature dependences of molar fractions and entropy of mixing are obtained. Quantum-chemical and empirical estimates of the standard enthalpy of formation are produced. The thermodynamic functions of ibuprofen in the gas phase are determined.
Microscopic dynamic mechanism of equilibration in crystals: one-dimensional model
Authors: Zakharov A Yu , Zakharov M A
Published: November 2021

The dynamics of free vibrations of a chain of atoms is investigated taking into account the retardation of interactions. It is shown that all oscillations of the circuit are damped. The dynamics of forced vibrations of this chain of atoms is investigated. It is shown that, regardless of the initial conditions, the system passes into a stationary state of dynamic equilibrium with an external field, which depends both on the properties of the system and on the parameters of the external field. A non-statistical dynamic mechanism of the process of irreversible establishment of the state of thermodynamic equilibrium in both many-body and few-body systems is proposed.
Preparation and characterization of graphene nanosheet doped with silver nanoparticles
Authors: Mohammed A H , Naje A N
Published: November 2021

Simple process (exploding wire technique) was used to Prepared sliver nanoparticles (AgNPs). The graphene sheet was added to AgNPs with different concentrations (0.002g/ml and 0.01g/ml). well dispersion of AgNPs are achieved by simple chemistry process. The samples were characterized by ultraviolet-visible spectroscopy (UV-Vis), x-ray diffraction (XRD), atomic force microscopy (AFM) and Field emission scanning electron microscope (FESEM). The results showed a wide band absorption of AgNPs-graphene (AgNPs-GN) extended from VU to IR region, surface plasmon resonance (SPR) absorption peak position for the AgNPs at (350-600) nm, XRD confirmed the clear distribution of the peaks attributed to polycrystalline for AgNPs appeared at 20=38.14°, 44.27°, 64.33, and 77.37° respectively and AgNPs-GN at 2θ=26.51° and 54.65°. The AFM showed that AgNPs have uniformly distribution on the surface of graphene sheet. The average size of AgNPs was confirmed by around (50-80) nm by FESEM and the AgNPs-GN have average particle size (20-40) nm. The AgNPs-GN could become prominent candidate for optoelectronic applications.
Neural Network Model for Synthesis of Thermally Sprayed (AI/AI2O3) Composite Protective Coatings
Authors: Jumah Thamir Abdul-Jabbar , Ahmed Saad Ali
Published: November 2021

Al2O3 and Al2O3–Al composite coatings were deposited on steel specimens using Oxy-acetylene gas thermal spray gun. Alumina was mixed with Aluminum in six groups of concentrations (0, 5, 10,12,15 and 20% ) Al2O3, Specimens were tested for corrosion using Potentiodynamic polarization technique. Further tests were conducted for the effect of temperature on polarization curve and the hardness tests for the coated specimens. At first, Modelling was carried out using MINITAB-19, least square method, as a 2nd degree nonlinear model, bad results were achieved because of the high nonlinearity. Better result was achieved using neural network fitting tool. The network was designed using five neurons in the hidden layer and the input was I input with two layers, the electrical potential and alumina concentration.
Synthesis of Composite from Bacterial Cellulose and Gold Nanoparticles
Authors: Ahmed Saad Ali , Ahmed Alaa Abdulnabi , Latif Mohamed Hassan Abdul
Published: November 2021

A process of bacterial cellulose gold nanocomposite has been investigated based on experimental work and cited literature. A literature review on the production process is carried out in this study. Bacterial cellulose is a high crystalline fabric material generally used in biomedical applications. A Nanocomposite was made by synthesis from gold and bacterial cellulose. The experimental work includes growing, and isolating bacterial cellulose, preparation of gold Nanoparticles and preparation of Nano composite. Nanoparticle’s formation and adsorption on the cellulose tissue have been observed visually, where a colour change was observed. The predicted particle size for the gold nanoparticles was (2-100) nm.
Lab build Fully Automated microfluduic flow injection System
Authors: Al-Asady Ihsan A , Al-Sowdani K H
Published: November 2021

A fully automated microfluidic Flow Injection spectrophotometric system was designed in our laboratory with methylene blue used as an example. The device consists of a double-line microfluidic chip with dimensions (30 μl x 4 cm), each 15 μl volume intended to allow a very small volume of reagent and sample to be used. The microfluidic system also consists of two types of Arduino software. The first was the UNO of a type used to control the two mini peristaltic pumps to drive the water and methylene blue as carrier stream and sample respectively. The Mega type, which was equipped with homemade software, signal-to-peak, was the second Arduino which used as a data logger to record the results in the form of peaks using Microsoft Excel 2016. The peak’s height was corresponding to concentration. The linearity was in the range (0.025-0.125 μg/ml) with a five-point regression coefficient (0.9981), RSD% for ten replicates is 0.025 μg/mL. The detection limit was (0.001 μg/ml) and the sample throughput was 300 samples per hour and each sample required 25 μl of chemical reagents. Therefore, 240 samples need only (5.0 ml) from the chemical reagents, which clearly indicates that the consumed reagent and the waste were very low. Therefore, the method for determining methylene blue with a fully automated system is very environmentally friendly. save time, consumption regent, Improve quality, decrease cost-consumption reducing the consume of sample and inherited the reproducibility and accurate from flow injection analysis.
Evaluation of synergistic medicinal efficacy of four alkaloidic compounds isolated from Iraqi Allium porrum seeds against staphylococcus aureus bacteria
Authors: Al-Maliki Abbas D M , Ai-Maliki Ala’a A H , Hameed Maha A A
Published: November 2021

Medicinal plants are necessary benefit natural sources for chemical production of different therapies from secondary metabolism. Allium porrum is considered as one of sources of foods and drugs at the same time. So the current work focused on isolation and characterization of four alkaloids from seeds of this plant. These compounds are 2-piperidinone, 2-pyrrolidinone-4-methyl, adenosine-2-deoxy–N-methyl –N-(triflouro acetyl ) and maymarsine by using Gas Chromatography – Mass Spectroscopy (GC-MS) technique. The medicinal activity was achieved to investigate and evaluate the synergistic action of the mixture of the four alkaloidic compounds towards Staphylococcus aureus pathogen. The concentrations of alkaloidic mixture were prepared with values equal to 50,100,125,150,200,250,300,375,400 and 500 mg/ml and they revealed inhibition zones with diameters represented by 31,31,32,35,35,37,41,43,43and 45 mm. So the mixture of the four alkaloidic compounds can be used as natural therapy to treat various inflammatory caused by this pathogenic bacteria.
Synthesis, characterization and spectral studies of mononuclear and binuclear Fe(II), Co (II), Ni (II), Zn(II) complexes with 2,4-dinitrophenylhydrazine dithiocarbamate
Authors: Mohammed Enas Hazim , Ahmed Sahbaa Ali , Zedan Sariya Waleed
Published: November 2021

New complexes of dithiocarbamate of the general formula [M(2,4-dinitrphenhydra - dtc)2], [MM’(2,4-dinithrphenhydra-dtc)4] where: M=Fe (II), Co(II), Ni(II), M’=Zn(II), 2,4- dinitrphenhydra-dtc=2,4- di nitro phenyl hydrazine dithiocarbamate and [M(l,10-phen)3][M’(2,4 – dinitrphenhydra-dtc)4], [M(1,10- phen)3][M’2(2,4-dinitrphenhydra - dtc)6] Where: M=Co(II), Ni(II), M’=Zn(II), (1,10-phen)= 1,10-phenanthroline monohydrate. Have been prepared and characterized by atomic absorption spectroscopy infrared, conductance measurements, electronic absorption spectra, nuclear magnetic resonance and magnetic susceptibility measurements. Magnetic moments and electronic spectra indicate that the complexes of the type [M(2,-dinitrphenhydra-dtc)2], [MM’(2,4-dinitrphenhydra - dtc)4] are of square planner geometry while the complexes of the type [M(1,10-phen)3][M’(2,4-dinitrphenhydra-dtc)4] and [M(1,10 phen)3][M’2(2,4-dinitrphenhydra-dtc)6] have octahedral geometry.