bluuebunny/crossref_metadata_2025_split huggingface dataset:
Between technochauvinism and human-centrism: Can algorithms improve decision-making in democratic politics?
Authors: König Pascal D. , Wenzelburger Georg 
Published: January 2021

AbstractThe promise of algorithmic decision-making (ADM) lies in its capacity to support or replace human decision-making based on a superior ability to solve specific cognitive tasks. Applications have found their way into various domains of decision-making—and even find appeal in the realm of politics. Against the backdrop of widespread dissatisfaction with politicians in established democracies, there are even calls for replacing politicians with machines. Our discipline has hitherto remained surprisingly silent on these issues. The present article argues that it is important to have a clear grasp of when and how ADM is compatible with political decision-making. While algorithms may help decision-makers in the evidence-based selection of policy instruments to achieve pre-defined goals, bringing ADM to the heart of politics, where the guiding goals are set, is dangerous. Democratic politics, we argue, involves a kind of learning that is incompatible with the learning and optimization performed by algorithmic systems.
Low cost technology for the fabrication of anti-counterfeiting microtaggants
Authors: Tomescu Roxana , Parvulescu Catalin , Cristea Dana , Comanescu Brandus , Pelteacu Mihaela 
Published: January 2021

Abstract
One of the most important responsibility of manufacturers is to protect their products against counterfeiting. Currently there are a large variety of protection methods based on security tags that can be attached to the products such as holographic labels, nanoparticles, encrypted messages, barcodes etc. The research in this area focuses on the possibility of adding extra security elements (ex: nanoparticles) or complicating the designs of the classical holographic labels. Here we present a simple and low-cost technology for the fabrication of metal microtaggants with different types of security elements engraved, such as holographic background with different visual effects and micro-texts, and etched alphanumerical elements. The main advantages of these structures are the possibility to combine different types of security elements and the relatively small dimension, in the hundreds of micrometres range, making them significantly hard to identify with the naked eye. Our structures can be incorporated into paints, inks, paper, or simply attached on the surface of the product.
Rectifying and spin filtering behavior of aluminum doped silicon carbide nanoribbons: the first principles study
Authors: Rahmani-Ivriq Nasim , Ahmadkhan Kordbacheh Amirhossein 
Published: January 2021

Abstract
In this paper, spin transport properties of aluminum-doped zigzag silicon carbide nanoribbons (Al-ZSiC NRs) are investigated using the first-principle calculations and the nonequilibrium Green’s function method. The results show an approximately perfect spin filtering (100%) for three considered models and undoped structure at ferromagnetic state in the presence of bias voltage. In particular, a weak negative differential resistance (NDR) phenomenon can be obtained in a certain system when replacing the edge Si atom with the Al-doping atom. Indeed, edge states play a crucial role in spin-dependent transport and magnetic properties of ZSiC NRs, such as the NDR effect. Furthermore, the significant rectifying ratio (RR) is obtained under bias voltage only for one given configuration. When the same spin states overlap in the bias window (BW), spin-dependent transmission and the spin current display a non-zero value; however, the mismatch of the same spin states within the BW region causes to vanish the transmission spectra. The controllable manipulation of threshold voltage, spin filtering efficiency, NDR behavior, and RR effect can be achieved by substituting of silicon with Al atom in ZSiC NRs. These results shed new light on our understanding of silicon carbide-based nanodevices with appealing spintronic applications.
Resonance phase and geometric phase integrated diffusion metasurface for broadband scattering control
Authors: Ying-Jie Wang , Ke Chen , Fang-Kun Zhou , Jiang-Xiao Tian , Yu-Feng Fu , Ping Chen 
Published: January 2021

Abstract
In this paper, we demonstrate a binary diffusion metasurface with a broadband radar cross section (RCS) reduction performance based on the integration of resonance and geometric phase manipulation. The working principle of such a metasurface was investigated and the general criterion for the electromagnetic (EM) responses of the meta-atom was derived. In particular, we deployed a split metallic ellipse ring with a beam along the short axis and its counterpart with a 90° inclined angle as the binary elements to construct the diffusion metasurface. EM responses of the proposed anisotropic meta-atom were explored in the framework of the equivalent circuit model. The inherent resonance phases of the meta-atom along its two symmetric axes were adjusted by changing its structural parameters. Then, we integrated the manipulation of the resonance phase and geometric phase together and designed a metasurface that can achieve broadband specular RCS reduction (more than −10 dB) from 4.3 GHz to 16.5 GHz. The RCS reduction performance of the metasurface is polarization-independent and shows a certain degree of stability under oblique incidence. For verification, a prototype with optimized structural parameters was fabricated and the measured results coincide well with the simulated results. Our work provides a convenient approach to realize a binary diffusion metasurface for the purpose of broadband RCS reduction.
Self-powered and temperature-tunable infrared-visible photodetector based on a VO2/Si heterojunction
Authors: Hassan Zamir Ul , Siddique Razwan , Sajjad Syeda Amna , Umer Zeshan Adeel , Bukhari Shujaht , Anwar-Ul-Haq Muhammad , Rafique Mohsin , Raza Syed Raza Ali 
Published: January 2021

Abstract
In this work, a type-III heterojunction based on a pulsed-laser-deposited vanadium dioxide (VO2) and p-type silicon (p-Si) substrate is realized. The device shows a large self-powered and room-temperature photoresponse to IR (950 nm), green (515 nm) and blue (456 nm) LEDs. A short-circuit current (I
sc) of ∼3 µA and an open-circuit voltage (V
oc) of ∼−120 mV are observed under IR LED illumination. The work function data in literature along with the sign of V
oc measurement is used to sketch the energy band diagram of the heterojunction. The temperature-dependent I
sc properties of the junction, contrary to conventional photodetectors, show an initial rise and then a sharp transition from maximum (3.5 μA) to almost zero near 337 K, corresponding to a metal–insulator phase transition, paving the way for photodetectors with temperature-tunable photoresponsivity.
Effect of nanoparticle shape on therapeutic temperature distribution during magnetic hyperthermia
Authors: Tang Yundong , Flesch Rodolfo C C , Jin Tao , Gao Yueming , He Minhua 
Published: January 2021

Abstract
Treatment temperature distribution is a crucial factor for magnetic hyperthermia, since it directly determines the treatment effect related to the apoptosis situation of malignant cells. The shape of magnetic nanoparticles (MNPs) is one of many factors that can affect the treatment temperature during therapy. This paper conducts a comparative study on three different shapes of MNPs by considering the effective area percentage of treatment temperature distribution. The treatment temperature for a proposed model is predicted by solving bio-heat transfer equations, which take the power dissipation of MNPs as the input and consider a temperature-dependent blood perfusion rate in these equations at the same time. The simulation results demonstrate that the treatment temperature distribution can be effectively improved when the temperature-dependent blood perfusion rate is used for the simulation with respect to a constant case. In addition, the MNPs with higher regular shape can lead to a better result than a lower case in the treatment temperature distribution when the same condition is considered for therapy.
All-MOCVD-grown gallium nitride diodes with ultra-low resistance tunnel junctions
Authors: Hasan Syed M N , Gunning Brendan P , J.-Eddine Zane , Chandrasekar Hareesh , Crawford Mary H , Armstrong Andrew , Rajan Siddharth , Arafin Shamsul 
Published: January 2021

Abstract
We carefully investigate three important effects including postgrowth activation annealing, delta (δ) dose and magnesium (Mg) buildup delay as well as experimentally demonstrate their influence on the electrical properties of GaN homojunction p–n diodes with a tunnel junction (TJ). The diodes were monolithically grown by metalorganic chemical vapor deposition (MOCVD) in a single growth step. By optimizing the annealing parameters for Mg activation, δ-dose for both donors and acceptors at TJ interfaces, and p
+-GaN layer thickness, a significant improvement in tunneling properties is achieved. For the TJs embedded within the continuously-grown, all-MOCVD GaN diode structures, ultra-low voltage penalties of 158 mV and 490 mV are obtained at current densities of 20 A cm−2 and 100 A cm−2, respectively. The diodes with the engineered TJs show a record-low differential resistivity of 1.6 × 10−4 Ω cm2 at 5 kA cm−2.
MoSi2N4 single-layer: a novel two-dimensional material with outstanding mechanical, thermal, electronic and optical properties
Authors: Bafekry A , Faraji M , Hoat D M , Shahrokhi M , Fadlallah M M , Shojaei F , Feghhi S A H , Ghergherehchi M , Gogova D 
Published: January 2021

Abstract
Very recently, the 2D form of MoSi2N4 has been successfully fabricated (Hong et al 2020 Science
369 670). Motivated by these recent experimental results, we investigate the structural, mechanical, thermal, electronic and optical properties of the MoSi2N4 monolayer. The mechanical study confirms the stability of the MoSi2N4 monolayer. The Young’s modulus decreases by ∼30%, while the Poisson’s ratio increases by ∼30% compared to the corresponding values of graphene. In addition, the MoSi2N4 monolayer’s work function is very similar to that of phosphorene and MoS2 monolayers. The electronic structure shows that the MoSi2N4 monolayer is an indirect semiconductor with a band gaps of 1.79 (2.35) eV using the GGA (HSE06) functional. The thermoelectric performance of the MoSi2N4 monolayer has been revealed and a figure of merit slightly larger than unity at high temperatures is calculated. The optical analysis shows that the first absorption peak for in-plane polarization is located in the visible range of the spectrum, therefore, the MoSi2N4 monolayer is a promising candidate for advanced optoelectronic nanodevices. In summary, the fascinating MoSi2N4 monoloayer is a promising 2D material for many applications due to its unique physical properties.
Pulsed laser ablation of binary compounds: effect of time delay in component evaporation on ablation plume expansion
Authors: Morozov A A , Starinskiy S V , Bulgakov A V 
Published: January 2021

Abstract
Pulsed laser ablation of compound materials often occurs with delayed evaporation of a less volatile component; however, the effect of the delay on ablation plume expansion remains virtually unexplored. Here, we have performed an experimental and theoretical study of the delayed evaporation effect using an example of a plume produced by nanosecond laser ablation of a gold–silver alloy in a vacuum and comparing it with ablation of pure gold and silver targets. The plume expansion dynamics are investigated by time-of-flight (TOF) mass spectrometry and direct simulation Monte Carlo (DSMC), while the laser-induced target evaporation is analyzed using a thermal model. A dramatic effect of the delay time on the average kinetic energy of the plume particles, especially for the less volatile gold, is demonstrated and the main collisional processes governing the two-component plume expansion under the conditions of delayed evaporation are revealed. Based on comparison of experimental and DSMC data, the delay of the gold evaporation onset is estimated as approximately 0.6 ns. The delayed evaporation is therefore an important factor for correct interpretation of TOF measurements in ablation plumes with components of different volatilities.
Ternary flower-sphere-like MnO2-graphite/reduced graphene oxide nanocomposites for supercapacitor
Authors: Yao Jun , Jia Yongfeng , Han Qingli , Yang Daotong , Pan Qingjiang , Yao Shanshan , Li Jiuming , Duan Limei , Liu Jinghai 
Published: January 2021

Abstract
Chemical fabrication of a nanocomposite structure for electrode materials to regulate the ion diffusion channels and charge transfer resistances and Faradaic active sites is a versatile strategy towards building a high-performance supercapacitor. Here, a new ternary flower-sphere-like nanocomposite MnO2-graphite (MG)/reduced graphene oxide (RGO) was designed using the RGO as a coating for the MG. MnO2-graphite (MnO2-4) was obtained by KMnO4 oxidizing the pretreated graphite in an acidic medium (pH = 4). The GO coating was finally reduced by the NaBH4 to prepare the ternary nanocomposite MG. The microstructures and pore sizes were investigated by x-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and nitrogen adsorption/desorption. The electrochemical properties of MG were systematically investigated by the cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy in Na2SO4 solution. The MG as an electrode material for supercapacitor exhibits a specific capacitance of 478.2 and 454.6 F g−1 at a current density of 1.0 and 10.0 A g−1, respectively. In addition, the capacitance retention was 90% after 8,000 cycles. The ternary nanocomposite enhanced electrochemical performance originates from the specific flower-sphere-like morphology and coating architecture bringing higher specific surface area and lower charge transfer resistance (Rct).
Valley manipulation in monolayer transition metal dichalcogenides and their hybrid systems: status and challenges
Authors: Zhao Siwen , Li Xiaoxi , Dong Baojuan , Wang Huide , Wang Hanwen , Zhang Yupeng , Han Zheng , Zhang Han 
Published: January 2021

Abstract
Recently, the emerging conceptual valley-related devices have attracted much attention due to the progress on generating, controlling, and detecting the valley degree of freedom in the transition metal dichalcogenide (TMD) monolayers. In general, it is known that achieving valley degree of freedom with long valley lifetime is crucial in the implementation of valleytronic devices. Here, we provide a brief introduction of the basic understandings of valley degree of freedom. We as well review the recent experimental advancement in the modulation of valley degree of freedom. The strategies include optical/magnetic/electric field tuning, moiré patterns, plasmonic metasurface, defects and strain engineering. In addition, we summarize the corresponding mechanisms, which can help to obtain large degree of polarization and long valley lifetimes in monolayer TMDs. Based on these methods, two-dimensional valley-optoelectronic systems based on TMD heterostructures can be constructed, providing opportunities for such as the new paradigm in data processing and transmission. Challenges and perspectives on the development of valleytronics are highlighted as well.
Substantial reduction of the anisotropy in the critical current densities J
c of Ni-doped CaKFe4As4 single crystals by chemical and irradiation-induced disorder
Authors: Haberkorn N , Xu M , Meier W R , Schmidt J , Suárez S , Bud’ko S L , Canfield P C 
Published: January 2021

Abstract
We demonstrate that the anisotropy in the critical current densities, J
c, of CaK(Fe1−x
Ni
x
)4As4 (x = 0, 0.015, 0.025, and 0.030) single crystals reduces with increasing chemical and irradiation-induced disorder. The magnetic field dependences of J
c are analyzed by performing magnetization measurements with H applied parallel and perpendicular to the crystallographic c-axis. The results show that undoped crystals display large anisotropies in J
c due to an enhancement of the vortex pinning with H applied parallel to the crystallographic ab-planes. This anisotropy reduces substantially as Ni addition increases. Moreover, we found that random disorder introduced by proton irradiation enhances mainly the vortex pinning for H parallel to the c-axis. Consequently, using adequate fluencies, the vortex pinning at low temperatures in both undoped and doped samples becomes close to isotropic. These results make the CaKFe4As4 system promising for applications that require isotropic J
c under magnetic fields.
Modeling study on high-temperature superconducting bulk’s growth anisotropy effect on magnetization and levitation properties in applied magnetic fields
Authors: Zheng Jun , Chen Nan , Zhang Weifeng , Deng Zigang 
Published: January 2021

Abstract
Fabricated by top-seeded melt-texture methods, high-temperature superconducting (HTS) bulk, such as YBaCuO bulk exhibits anisotropic properties of the critical current density J
c spatial distribution in growth sector regions and growth sector boundaries (GSBs). It was found that the YBaCuO bulk arrangement optimization considering the J
c spatial distribution above a permanent magnet guideway (PMG) enhances the levitation performance of the HTS magnetic levitation (maglev) system according to the past experiments. Therefore, from the point of view of practical applications, a theoretical model describing this HTS growth anisotropy is required to reproduce its effect on HTS maglev properties. In this study, we proposed an updated J
c spatial function with an adjustment parameter to better describe HTS bulk’s growth anisotropy. Its Cartesian form is suitable for differently shaped bulk superconductors. We subsequently established a 3D simulation model of an HTS–PMG maglev system and completed the calculations of both the levitation force and decay of two different bulk arrangements above the PMG. The calculation results are consistent with the experimental results, which verifies the reliability of the 3D HTS–PMG maglev model and J
c spatial function. Further, all results show that a more stable HTS levitation with a larger levitation force is generated in the case where the GSB is aligned with the longitudinal direction of the PMG’s largest magnetic field. This provides a reference for HTS maglev designs. Furthermore, the modeling can be a useful tool for optimizing the HTS–PMG maglev system for several scenarios.
Spectral red-shift of solid high-order harmonic generation combining a fundamental field and a terahertz field
Authors: Pan Xue-Fei , Li Bo , Huo Xiao-Xin , Zhang Jun , Liu Xue-Shen 
Published: January 2021

Abstract
High-order harmonic generation (HHG) from a solid by combining a fundamental field and a terahertz field is investigated by solving the time-dependent Schrödinger equation. The numerical results illustrate that the red-shift from odd harmonics is more obvious in the combined field than the fundamental field. We have also investigated solid HHG with different relative phases. We find that the HHG spectra exhibit a larger red-shift from odd harmonics for the relative phase φ = 0 and the red-shift from odd harmonics is gradually weakened by increasing the relative phase. For the relative phase φ = π, the red-shift of solid HHG disappears and only odd harmonic order can be observed. The time-dependent population imaging picture is used to illustrate the physical mechanism of the red-shift in solid HHG.
Vector soliton generation from a compact all-polarization-maintaining fiber laser
Authors: Wu Zhichao , Zhan Bingye , Li Lu , Huang Tianye , Wei Qian , Zhang Dazhong , Shum Perry Ping 
Published: January 2021

Abstract
We investigate polarization-locked vector solitons (PLVSs) arising in an all-polarization-maintaining (PM) soliton fiber laser mode-locked by a carbon nanotube. The laser can operate stably in both Q-switched and mode-locked states with different pump power. Under the PLVS condition, we observe a string of peak-dip-pair sidebands after polarization-resolving measurement, indicating the strong and regular energy exchange between the two polarized orthogonal components, which evidently distinguishes this all-PM fiber laser from conventional single-mode fiber-based vector cavities. By dispersion compensating, vector dissipative solitons are also successfully obtained. The cavity structure is greatly simplified and stabilized by a hybrid fiber component and shows excellent long-term stability.
Pozzolanic Properties of Agro Waste Ashes for Potential Cement Replacement Predicted using ANN
Authors: Manikanta C , Manikandan P , Duraimurugan S , Elavenil S , Vasugi V 
Published: January 2021

Abstract
Every year, cement demand increases due to infrastructural development in our country, which indirectly increases global warming since the manufacturing of Portland cement emits a large volume of carbon dioxide into the atmosphere. Hence, the demand of using Portland cement should be reduced by using various types of mineral admixtures as a replacement to Cement. In India, every year agricultural sector produces a large volume of waste by-products like corncob, rice husk, sugarcane bagasse, bamboo leaves etc., which could be burnt in a controlled environment and the resulted ashes could be used as partial replacement to Cement. The pozzolanic activity of agro-waste ashes like rice husk ash, cocoa fruit shell ash, corncob ash, bamboo leaves ash, sugarcane bagasse ash have been tested and compared using the strength activity test, the saturated lime test and the Frattini test with the implementation of Artificial Intelligence using Neural Network was carried out. It is observed that Rice husk ash, corncob ash, bamboo leaf ash, sugar cane bagasse ash have the potential to be replaced for Cement while cocoa fruit shell ash does not have the expected pozzolanic activity. The predicted pozzolanic strength property of the different agro-waste ashes with the utilization of Artificial Neural Network was observed to correspond with experimental values.
Remaining useful life estimation of a Product
Authors: Murali Krishna K , Janardhan Reddy Dr K 
Published: January 2021

Abstract
A sudden failure of a product or a component may result in loss of valuable data or interruption in the task being carried out. In order to eliminate these kind of scenarios and to avoid unnecessary investments on the used products, the remaining life need to be predicted/estimated. In this work, a comprehensive two-phase approach is proposed. In the first stage phase, statistically analyzing the behavior of components for reuse, a well-known reliability assessment method, the Weibull analysis, is applied to the time-to-failure data to assess the mean life of components. In the second phase, the degradation and condition monitoring data are analyzed by developing an Artificial Neural Network model (ANN model). This project is aimed on estimating the remaining useful life of washing machine and LED bulb