bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient indoor localization with wireless sensor networks via learnable sparse coding
Authors: Li Xiang
Published: September 2023

In this study, the indoor localization problem for human movement is built as a sparse representation, and a learnable sparse coding algorithm is proposed by introducing a nonconvex penalty function as the sparse constraints. The good properties of the penalty are able to help reduce the iteration cost to find a sparse solution indicating the target locations. The sparse code can achieve its optimal value from the trained neural network model with parametrization. It is instead of a piece of algorithmic processing in the conventional methods requiring a large iteration. A real-world experiment using a Bluetooth low energy wireless sensor network validates the proposed method and shows the improvement of the error reduction at the first five iteration points on average compared to iterative shrinkage and thresholding algorithm (ISTA), and achieves competitive performance in the localization tasks for learned-ISTA-based algorithms.
Mechanochemical preparation of low cost kaolinite-based BiVO4 hybrid pigments with high near infrared reflectance
Authors: Wang Xiaowen , Mu Bin , Li Shue , Lu Yushen , Wang Aiqin
Published: September 2023

For accelerate construction of the energy and resource-saving and environmental-friendly society, cleaner preparation of low-cost and high-performance colorful near-infrared reflective inorganic pigments with the decorative function is indispensable to reduce the hazards of urban heat island and simultaneously beautify the appearance of the buildings. Due to the non-toxicity, good chemical stability and narrow band gap, BiVO4 has been becoming a promising environment-friendly yellow inorganic pigments among the conventional heavy metals-containing inorganic pigments. In this study, the low-cost and brilliant kaolinite-based BiVO4 hybrid pigments were fabricated by cleaner mechanochemical method based on cheap and abundant kaolinite using crystal water of the hydrated metal salts as trace solvent, which could effectively promote the interaction of the involved components at the molecular level during grinding and then decreased the mass transfer resistance for the formation of monoclinic scheelite BiVO4 in the following calcination. The obtained hybrid pigments at the optimal preparation conditions exhibited brilliant color properties (D65-10°, L

*
= 83.45 ± 0.08, a

*
= 4.17 ± 0.08, b

*
= 88.59 ± 0.17), high near-infrared reflectance of 86.22%, infrared solar reflectance of 88.14% and high emissivity of 0.9369 in the waveband of 8–13 μm. Furthermore, the hybrid pigments could be used for coloring epoxy resin with high emissivity of 0.8782 in 8–13 μm. Therefore, the brilliant and low-cost kaolinite-based bismuth yellow hybrid pigments have the enormous potential to be served as colorful functional nanofillers for cooling roofing materials.
Adhesion and morphology of mammalian cells on nanoporous and nonporous spherical carbon substrates
Authors: Osuchowski Łukasz Paweł , Dobrzyńska Monika , Kasprzycka Wiktoria , Osuchowska Paulina Natalia , Szczęśniak Barbara , Mierczyk Zygmunt , Trafny Elżbieta Anna
Published: September 2023

Three spherical activated carbons (SACs) were used as substrates for mammalian cell proliferation. SACs were obtained by carbonizing styrene-co-divinylbenzene ion exchangers 35WET, XAD4, or 1200H. The new materials (XAD_C, WET_C, and H_C) were characterized by adsorption–desorption nitrogen isotherms and mercury intrusion porosimetry. XAD_C and WET_C exhibited well-developed BET surface areas, similar total pore volumes, and highly different pore size distributions. H_C was nonporous spherical material—reference material. The XAD_C was meso-macroporous, but the WET_C was micro-mesoporous. All SACs were not cytotoxic toward Leydig TM3 cells. The differences in porous structure and morphology of the carbon scaffolds led to morphological differences in adhered cells. The monolayer of cells was distributed flat over the entire WET_C and H_C surfaces. Leydig TM3 cells adhered to nonporous SAC but were easily washed out due to weak adhesion. The cells adhered in clusters to XAD_C and proliferated in clusters. As microscopic techniques and viability tests demonstrated, only nanoporous carbons provided a good surface for the attachment and proliferation of eukaryotic cells.
Dark-field optical fault inspection of ∼10 nm scale room-temperature silicon single-electron transistors
Authors: He Wenkun , Chu Kai-Lin , Abualnaja Faris , Jones Mervyn , Durrani Zahid
Published: September 2023

Dark-field (DF) optical microscopy, combined with optical simulation based on modal diffraction theory for transverse electric polarized white light, is shown to provide non-invasive, sub-wavelength geometrical information for nanoscale etched device structures. Room temperature (RT) single electron transistors (SETs) in silicon, defined using etched ∼10 nm point-contacts (PCs) and in-plane side gates, are investigated to enable fabrication fault detection. Devices are inspected using scanning electron microscopy, bright-field (BF) and DF imaging. Compared to BF, DF imaging enhances contrast from edge diffraction by ×3.5. Sub-wavelength features in the RT SET structure lead to diffraction peaks in the DF intensity patterns, creating signatures for device geometry. These features are investigated using a DF line scan optical simulation approximation of the experimental results. Dark field imaging and simulation are applied to three types of structures, comprising successfully-fabricated, over-etched and interconnected PC/gate devices. Each structure can be identified via DF signatures, providing a non-invasive fault detection method to investigate etched nanodevice morphology.
A sheath correction method for electron density measurements with the microwave resonant curling probe
Authors: Boni Federico , Désangles Victor , Jarrige Julien
Published: September 2023

A correction method accounting for plasma sheath effects that appear when performing an electron density measurement with a microwave resonant probe immersed in plasma is described. The diagnostic is the novel curling probe (CP) that has already shown promising capabilities in various plasma sources. The correction method is based on the evaluation of two effects relative to the resonant probe operation and its interface with the plasma. First, the characteristic decay length of the electromagnetic field emitted by the CP, which defines the probed volume, has been characterized for the different harmonic resonance modes. Second, a semi-analytical model has been adapted to describe the plasma structure forming near the probe, which quantitatively describes the electron density profiles across the sheath structure. The correction method is then developed uniquely from numerical simulations and is independent of other diagnostics. Experimental results inside two plasma sources, an inductively coupled plasma and an electron cyclotron resonance plasma thruster, are presented and discussed. The validity of the method is assessed (i) by comparing CP corrected densities with Langmuir probe results, (ii) by varying the probe orientation to the expanding plasma flow, and (iii) by using two harmonics of the probe. The method is shown to significantly improve the accuracy of electron density measurements. Possible improvements to the method are also discussed.
A xenon collisional-radiative model applicable to electric propulsion devices: III. Determination of the ionization fraction in low-temperature xenon plasma by using ionic and atomic 6p lines
Authors: Zhu Xi-Ming , Wang Yan-Fei , Meng Sheng-Feng , Wang Yang , Ning Zhong-Xi , Yu Da-Ren , Bartschat Klaus
Published: September 2023

The ionization fraction is a key figure of merit for optimizing the performance of plasma device. This work presents an optical emission spectroscopy (OES) method to determine the ionization fraction in low-temperature xenon plasma. The emission line-ratio of xenon ionic and atomic 6p–6s transitions is used in this method. A comprehensive collisional-radiative model developed in our previous work is employed to describe the relationship between the line-ratios and the plasma parameters. It is found that some special line-ratios have a sensitive relationship to the ionization fraction, e.g. the ratio of the 460.30 nm line and 828.01 nm lines. These line-ratios are selected for the diagnostic method. The method is demonstrated in a magnetized discharge chamber. The axially-resolved emission spectra of the ionization chamber are measured, and from those the ionization fraction along the chamber axis is determined via the OES method. The axially-resolved ionization fraction is found to be dependent on the magnetic field and agrees well with those obtained from a Langmuir probe. In the experiment, the probe is overheated under some conditions, possibly due to the bombardment by energetic particles. In this case, no results can be obtained from the probe, while the OES method can still obtain reasonable results. Combined with optical tomography and spectral imaging technology, the OES method can also provide the spatial distribution of the ionization fraction, which is needed for revealing the discharge mechanisms of plasma devices.
Enhanced directionality of active processes in a viscoelastic bath
Authors: Das Biswajit , Paul Shuvojit , Manikandan Sreekanth K. , Banerjee Ayan
Published: September 2023

Active fluctuations are known to play a significant role in the intracellular transport of passive objects. However, the effect of viscoelasticity of the environment in shaping such processes is relatively less understood. Here, with a minimal experiment using a driven colloid in a viscoelastic bath, we show that viscoelasticity significantly increases the mean injected power to the passive object (

∼

50
%

compared to a viscous medium), for the same strength of the external driving. Additionally, we observe a notable reduction in negative work fluctuations across a wide range of driving amplitudes. These findings collectively suggest an enhanced directionality in driven processes within a viscoelastic bath, which we attribute to the emergence of interactions between the colloid and the viscoelastic medium.
Performance assessment of pocket tunnel FET and accumulation mode FET for detection of streptavidin protein
Authors: Jadhav Akash , Yadav Shivendra , Pandey Sushil K , Garg Vivek , Dwivedi Praveen
Published: September 2023

In this paper, Dielectrically Modulated (DM) pocket Tunnel Field Effect Transistor (TFET) and Accumulation Mode Field Effect Transistor (AMFET) biosensors are examined for the Sensitivity estimation of different thicknesses of biotarget (Streptavidin)/bioreceptor (Biotin)/silica binding protein (SBP or APTES) biomolecules with a fully filled and partially filled cavity. The sensitivity parameter is based on realistic process detection and is calculated as the ratio of biotarget to bioreceptor drain current for neutral and charged biomolecules. The effect on the sensitivity for a filled cavity is observed for: a) varying the thickness of streptavidin and Biotin for fixed SBP (APTES) thickness, b) varying the thickness of streptavidin and APTES for fixed biotin thickness, for both Pocket TFET and AMFET. The maximum sensitivity is observed in 4 nm thick streptavidin for the front gate voltage V
fg: −3.8 V and V
fg: −1.6 V for pocket TFET and AMFET, respectively.
Correlation between critical magnetic behavior and griffiths phase in ferromagnetic La0.7Sr0.3Mn1−xFexO3 (x = 0.05) nanoparticle
Authors: Thanh Tran Dang , Van Quynh Nguyen , Thi Ngoc Nha Tran , Nam Pham Hong , Manh Do Hung , Phong Pham Thanh
Published: September 2023

The magnetic behavior of the La0.7Sr0.3Mn0.95Fe0.05O3 nanoparticles was investigated. X-ray diffraction analysis revealed that this sample exhibited rhombohedral symmetry with

R

3

̅

c

space group. The sample underwent a ferromagnetic-paramagnetic transition at approximately 290 K, characterized by a second-order phase transition. Interestingly, the state above the transition temperature is not purely paramagnetic but rather exhibits a short-range ferromagnetic order or Griffiths phase, which becomes more pronounced as the temperature increases up to the Griffiths transition temperature (

∼

345 K). The values of the critical exponents obtained in this study, β = 0.671, γ = 1.087, and δ = 2.612, with T
C = 290.09 K, are distinct from those of any known universality class, and are confirmed by a single scaling equation of state. This unusual behavior is ascribed to the existence of the Griffiths phase, which reflects the unconventional critical behavior of magnetic susceptibility. In addition to conventional magnetic measurements, detailed studies of isothermal magnetization and magnetocaloric effects have been performed, and theoretical analyses have been utilized to further explore the Griffiths phase. Furthermore, a correlation between the Griffiths phase and the anomalous critical parameters was established.
Improve characteristics of GaN-based green mini-LEDs with double dielectric sidewall passivation
Authors: Shen Meng-Chun , Guo Wenan , Chen Jinlan , Lin Su-Hui , Li Saijun , Lai Shouqiang , Lu Tingwei , Huang Min , Kuo Hao-Chung , Chen Zhong , Wu Tingzhu
Published: September 2023

The technique of double dielectric sidewall passivation could improve the electroluminescence characteristics of green mini-LED, including the leakage current, electroluminescence intensity and external quantum efficiency (EQE). According to the analysis of EQE with ABC + f(n) model, both the increment of size and the sidewall passivation could reduce the fraction of SRH recombination. Then, the results of time-resolved photoluminescence measurement indicated that the carrier lifetime of mini-LEDs with higher surface-volume ratio and sidewall passivation would be reduced. Moreover, the communication performances such as modulation bandwidth and frequency response of green mini-LEDs could also be improved by adopting double dielectric sidewall passivation, and the smaller sized green mini-LEDs could achieve higher modulation bandwidth and frequency response.
Isomeric pair 95
m,g
Nb in the photonuclear reactions on natMo at the bremsstrahlung end-point energy of 38–93 MeV
Authors: Timchenko I.S. , Deiev O.S. , Olejnik S.M. , Potin S.M. , Kushnir V.A. , Mytrochenko V.V. , Perezhogin S.A. , Bocharov V.A.
Published: September 2023

The

photonuclear reaction was studied using the electron beam from the NSC KIPT linear accelerator LUE-40. The experiment was performed using the activation and off-line γ-ray spectrometric technique. The experimental isomeric yield ratio (IR) was determined for the reaction products

at the bremsstrahlung end-point energy

range of 38–93 MeV. The obtained values of IR are in satisfactory agreement with the results of other studies and extend the range of previously known data. The theoretical values of the yields

and the IR for the isomeric pair

from the

reaction were calculated using the partial cross-sections

from the TALYS1.95 code for six different level density models. For the investigated range of

, the theoretical dependence of IR on energy was confirmed – the IR smoothly increases with increasing energy. The comparison showed a noticeable difference (more than 3.85 times) in the experimental IR relative to all theoretical estimates.
Cryogenic phonon-detector model with solid argon for detecting dark matter*
Authors: Liu 刘 Yu 钰 , Zhang 张 Lei 磊 , Yan 鄢 Yulu 雨璐 , Lin 林 Shin-Ted 兴德 , Liu 刘 Shukui 书魁 , Zhu 朱 Jinjun 敬军 , Tang 唐 Changjian 昌建 , Xing 幸 Haoyang 浩洋
Published: September 2023

Over the past few years, phonon detectors have emerged as a prevailing technology for detecting low-mass dark matter due to their low thresholds and high resolution. These detectors, which employ either dual-phase detectors combining phonon-light or phonon-electron interactions, have significantly advanced direct dark matter detection efforts. Argon, as a low-background and high-reserve detection medium, has also played a crucial role in this field. Both liquid-argon single-phase detectors and gas-liquid two-phase time projection chambers (TPCs) have contributed substantially to the direct detection of high-mass dark matter. By integrating these distinct detector types, the upper limits of the corresponding mass cross-section in dark matter detection can be lowered. We propose a phonon detector utilizing solid argon as the absorber, which combines the advantages of both aforementioned detector types. However, due to the requirement for an ultra-low temperature environment in the tens of millikelvin (mK) range, experimental investigations of solid argon phonon detector performance are currently constrained by technical limitations. Therefore, the performance analysis of the solid argon phonon detector presented in this study is only based on sapphire phonon detectors. Although there may be discrepancies between this approximation and the actual performance, the intrinsic characteristics of phonon detectors permit a qualitative evaluation of the solid argon phonon detector's potential capabilities.
Probing light DM via the Migdal effect with spherical proportional counter*
Authors: Gu 顾 Yuchao 玉超 , Tang 唐 Jie 杰 , Wu 武 Lei 雷 , Zhu 祝 Bin 斌
Published: September 2023

Owing to its low electronic noise and flexible target materials, the Spherical Proportional Counter (SPC) with a single electron detection threshold can be utilized to search for sub-GeV dark matter (DM). In this study, we investigate the prospects for light DM direct detection via the DM-nucleus Migdal effect in the DARKSPHERE detector. We consider different DM velocity distributions and momentum-transfer effects. For Xenon and Neon targets, we find that the DM mass

can be probed down to as low as

(10) MeV, and the derived bounds on the DM-nucleus scattering cross section

are sensitive to the high-velocity tails of the DM velocity distribution, which can be altered by orders of magnitude for the different DM velocity distributions in the region

MeV.
Light Higgs boson in the NMSSM confronted with the CMS di-photon and di-tau excesses*
Authors: Li 李 Weichao 为超 , Qiao 乔 Haoxue 豪学 , Zhu 朱 Jingya 经亚
Published: September 2023

In 2018, the CMS collaboration reported a di-photon excess at approximately 95.3 GeV with a local significance of 2.8 σ. Interestingly, the CMS collaboration also recently reported a di-tau excess at

GeV with a local significance of

. In addition, a

excess at 98 GeV with a local significance of 2.3 σ was reported from LEP data approximately twenty years ago. In this study, we addressed the interpretation of these excesses together with a light Higgs boson in the next-to-minimal supersymmetric standard model (NMSSM). We conclude that, in the NMSSM, the

GeV excesses are difficult to be satisfied simultaneously (not possible globally at the

level or simultaneously at the

level). We analyzed two partially-satisfied scenarios: global

and small di-photon. An approximate equation of global fit to the three excesses was derived, and two representative types of surviving samples were analyzed in detail. Given that the mass regions of these excesses are near the Z boson, we also checked the light Higgs boson in the

-associated channels. The detailed results may be useful for further checking the low-mass-region excesses in the future.
Compound control of rail pressure in dual common rail injection system based on a dual regulating valve
Authors: Wang Jun , Liu Yanbin , Zhang Zhiyuan
Published: September 2023

To improve the performance of fuel injection in high power diesel engines, high pressure dual common rail system (HPDCRS) is made to match high power diesel engine, proportional-integral-derivative (PID) compound control for rail pressure is proposed based on dual regulating valve: pressure balance valve (PBV) and pressure control valve (PCV), a PID hybrid neural network (PID-HNN) is provided to complete tuning and match of PID coefficient automatically, simulation control modelling of rail pressure is made by MATLAB software, pressure control comparison of dual common rail is made with PID compound control method. The pressure control effects illustrated that PID compound control of dual regulating valves can rapidly trace different target pressure and reduce rails pressure wavelet, and feasibility of compound control is verified in dual common rail pressure.
High-precision deformation prediction for compliant parts in the ship sub-assembly process
Authors: Jin Xuancheng , Zhang Kaigan , Xu Yuhui , Cao Lei , Ding Yutong , Seidelmann Joachim , Xia Tangbin
Published: September 2023

In the ship sub-assembly process, large compliant parts are common and generally thin. These compliant parts are normally easy to deform under the influence of gravity, which will greatly affect the accuracy of the sub-assembly processes. Thus, it is important to predict the deformation of the compliant part under a given fixture layout in advance. In current practice, existing methods of post-compensation are usually used to correct the deformation of the compliant part, which are inefficient and costly. In this paper, a transformer-based surrogate model with two-stage Latin hypercube sampling (TSM-TSS) is established. This surrogate model considers each fixture position and its deviation to predict the deformation of the entire compliant part. Compared with BPNN and Kriging, a case study reveals that TSM-TSS can predict the deformation of compliant parts with an error of 0.061mm. With the application of TSM-TSS, the deformation of the compliant part under gravity can be predicted accurately and the efficiency of shipbuilding can be improved.
A novel sandwich structured wheel to achieve mirror finish in grinding of a mould steel
Authors: Lin Feihong , Liu Chao , Tang Xiaotian , Liu Cheng , Guo Ke , Jin Tan , Shang Zhentao
Published: September 2023

A novel manufacturing tool called sandwich flexible elastic grinding wheel is developed to achieve high material removal rates and machined finish of a mould steel. This tool is made of aluminium matrix, ethylene propylene rubber layer and abrasive layer. Ethylene propylene rubber layer has great elasticity and produces elastic deformation when contacting with the workpiece. With the existence of an abrasive layer, rigidity at small scales allows grinding to occur, which can effectively remove the residual height of the surface and improve the surface quality. In this paper, influences of grinding process parameters of the sandwich elastic grinding wheel on the key characterisation parameters of surface integrity are studied, and the surface roughness and material removal rates under various process parameters are investigated. Then, the process parameters that are suitable for mirror machining are selected by experiments and are demonstrated on an S136 mould steel workpiece. Mirror finish can be achieved by single processing. The surface roughness of the mould steel converges from the original Ra142 nm to Ra7.42 nm, the surface texture is more compact and regular, and the surface integrity is significantly improved.
A pot-core eddy current sensor based on DC magnetization
Authors: Ou Zhengyu , Dong Shihao , Xu Cheng , Cen Jisong , Han Zandong
Published: September 2023

Due to the limitation of the skin effect of traditional eddy current sensors, it is difficult to sense internal defects. This paper proposes a pot-core eddy current sensor based on DC magnetization, which uses DC magnetization to excite the permeability perturbation of internal defects in the surface of samples and uses a pot-core eddy current sensor with higher efficiency to sense the perturbation, thus realizing the detection of defects. The phenomenon of permeability perturbation is analyzed by simulation, and experiments are conducted to verify the performance of the sensor. Also, the effects of magnetizing current and defect size are investigated experimentally. The results show that the sensor can realize the detection of the small internal defect with an unsaturated magnetizing current.
Study on calibration method of electrical parameter tester for industrial digital electronic detonator
Authors: Deng Bin , Zhao Dongsheng , Wang Dalong , Jia Ru , Sun Xiaoyan , Ma Xuefeng , Guan Zexin , Dong Guangkun , Wang Xinyan , Yan Hongrui , Chen Wenshu
Published: September 2023

By the end of 2022, the civil explosive industry has realized the full use of industrial electronic detonators, which has promoted the upgrading of the electrical parameter tester of industrial electronic detonators. The original calibration method can no longer meet its traceability requirements. According to the working principle of the industrial digital electronic detonator electrical parameter tester, this paper studies the calibration method of the delay time, DC resistance (firing bridge wire resistance), DC current, internal crystal oscillator signal (frequency) and other parameters, simulates and assembles a set of measuring standard device, and analyzes the sources of uncertainty of the industrial digital electronic detonator electrical parameter tester, which is solved the problem of quantity value traceability of industrial digital electronic detonator electrical parameter tester in civil explosive industry.
Large-scale stealth trajectory optimization based on hybrid A*-Gauss pseudospectral method
Authors: Qiu Jiaduo , Xiao Shaoqiu
Published: September 2023

For airborne electronic countermeasures, a practical and feasible stealth trajectory with low observability significantly impacts mission success. However, for long-range and large-scale trajectory optimization problems, the significant increase in the state space size will affect the feasibility and optimality of the problem solution. This paper proposes a hybrid trajectory optimization method to address the above issues. First, the A* (A-star) algorithm and cubic B-spline curve fitting method are used to generate the corresponding waypoints in the predetermined grid map under the radar detection threat to satisfy the trajectory stealth effect at the macro level. Then, the optimal control model (OCP) with the shortest flight time is solved between the waypoints to obtain segmented trajectories. Finally, the above state-control variable sequences are further used to solve the optimal control problem of the micro-level stealth trajectory coupling the radar cross section (RCS) by Gauss pseudospectral method (GPM). The numerical simulation results validate the proposed hybrid optimization method.
Leading role of outer-Arctic circulation transport in AMOC response to global warming over a century
Authors: Chen Jiao , Wang Xidong , Wang Xuezhu , Semmler Tido
Published: September 2023

Using the Alfred Wegener Institute Climate Model (AWI-CM 1.1 LR), we explored how Arctic and extra-Arctic warming affect the response of Atlantic meridional overturning circulation (AMOC) to quadruple carbon dioxide (4 × CO2) forcing. The results suggest that AMOC weakening is mainly affected by circulation adjustment caused by extra-Arctic warming, while Arctic warming has a limited local impact and a relatively small contribution to AMOC weakening. Due to the warming outside the Arctic, the increase in northward advective heat transport dominates the weakening of deep convection in Nordic Seas. While in the Labrador Sea, the decrease in advection heat transport is compensated by a more significant decrease in ocean heat loss to the atmosphere, leading to an enhancement of the upper ocean stratification. Besides, the weakening of deep convection associated with AMOC response under global warming is more pronounced in Nordic Seas than in Labrador Sea.
Local wellposedness of the relativistic Vlasov–Poisson equation in Besov space
Authors: Wang Yiliu , Zhang Xianwen
Published: September 2023

We obtain the local existence and uniqueness of solution to the relativistic Vlasov–Poisson system in Besov space, extending the non-relativistic result to the relativistic case. Weaker regularity is required for the initial datum by optimizing the commutator estimates related to the field. Commutator estimates associated with relativistic velocity are proved by dyadic decomposition of the frequency space and the decreasing properties of Bessel potential.
Temperature dependent temporal coherence of metallic-nanoparticle-induced single-photon emitters in a WSe2 monolayer
Authors: von Helversen Martin , Greten Lara , Limame Imad , Shih Ching-Wen , Schlaugat Paul , Antón-Solanas Carlos , Schneider Christian , Rosa Bárbara , Knorr Andreas , Reitzenstein Stephan
Published: September 2023

In recent years, much research has been undertaken to investigate the suitability of two-dimensional materials to act as single-photon sources with high optical and quantum optical quality. Amongst them, transition-metal dichalcogenides, especially WSe2, have been one of the subjects of intensive studies. Yet, their single-photon purity and photon indistinguishability remain the most significant challenges to compete with mature semiconducting systems such as self-assembled InGaAs quantum dots. In this work, we explore the emission properties of quantum emitters in a WSe2 monolayer which are induced by metallic nanoparticles. Under quasi-resonant pulsed excitation, we verify clean single-photon emission with a g
(2)(0) = 0.036 ± 0.004. Furthermore, we determine the temperature dependent coherence time via Michelson interferometry, where a value of (13.5 ± 1.0) ps is extracted for the zero-phonon line at 4 K, which reduces to (9 ± 2) ps at 8 K. Associated time-resolved photoluminescence experiments reveal a decrease of the decay time from (2.4 ± 0.1) ns to (0.42 ± 0.05) ns. This change in decay time is explained by a model which considers a Förster-type resonant energy transfer process which yields a strong temperature induced energy loss from the single-photon emitters to the nearby Ag nanoparticle.
Evaluating the performance of electrical discharge face grinding on super alloy monel 400
Authors: Kulshrestha Akshat Srivastava , Haldar Barun , Unune Deepak Rajendra , Dargar Ashok Kumar
Published: September 2023

Conventional machining of super alloy Monel 400 is difficult due to its high strength, low heat conductivity, and gummy nature. In this work, the performance of the electrical discharge diamond face grinding (EDDFG) while processing supper alloy Monel 400 is assessed using the super abrasive diamond-coated grinding wheels of three different grit numbers. Preliminary experiments highlighted the superior performance of the EDDFG as compared to that of electrical discharge machining (EDM) and electrical discharge face grinding (EDFG); in terms of material removal rate (MRR), average surface roughness (Ra), and microscopic images of surfaces using scanning electron microscope (SEM). This work aimed to assess the influence of the diamond grit number (DG

n
) of the grinding wheel along with other process parameters, viz. grinding wheel speed (GWS), peak current (I

p
), and pulse-on-time (T

on
) on Ra and MRR. The analysis of variance (ANOVA) confirmed that DG

n
and GWS significantly affect the response variables. Finally, the multi-objective genetic algorithm (GA) optimization approach was used to determine the optimal parametric settings of the EDDFG process.
Hopf Monoids and Generalized Permutahedra
Authors: Aguiar Marcelo , Ardila Federico
Published: September 2023

Generalized permutahedra are polytopes that arise in combinatorics, algebraic geometry, representation theory, topology, and optimization. They possess a rich combinatorial structure. Out of this structure we build a Hopf monoid in the category of species.

Species provide a unifying framework for organizing families of combinatorial objects. Many species carry a Hopf monoid structure and are related to generalized permutahedra by means of morphisms of Hopf monoids. This includes the species of graphs, matroids, posets, set partitions, linear graphs, hypergraphs, simplicial complexes, and building sets, among others. We employ this algebraic structure to define and study polynomial invariants of the various combinatorial structures.

We pay special attention to the antipode of each Hopf monoid. This map is central to the structure of a Hopf monoid, and it interacts well with its characters and polynomial invariants. It also carries information on the values of the invariants on negative integers. For our Hopf monoid of generalized permutahedra, we show that the antipode maps each polytope to the alternating sum of its faces. This fact has numerous combinatorial consequences.

We highlight some main applications:

We obtain uniform proofs of numerous old and new results about the Hopf algebraic and combinatorial structures of these families. In particular, we give optimal formulas for the antipode of graphs, posets, matroids, hypergraphs, and building sets. They are optimal in the sense that they provide explicit descriptions for the integers entering in the expansion of the antipode, after all coefficients have been collected and all cancellations have been taken into account.

We show that reciprocity theorems of Stanley and Billera–Jia–Reiner (BJR) on chromatic polynomials of graphs, order polynomials of posets, and BJR-polynomials of matroids are instances of one such result for generalized permutahedra.

We explain why the formulas for the multiplicative and compositional inverses of power series are governed by the face structure of permutahedra and associahedra, respectively, providing an answer to a question of Loday.

We answer a question of Humpert and Martin on certain invariants of graphs and another of Rota on a certain class of submodular functions.

We hope our work serves as a quick introduction to the theory of Hopf monoids in species, particularly to the reader interested in combinatorial applications. It may be supplemented with Marcelo Aguiar and Swapneel Mahajan’s 2010 and 2013 works, which provide longer accounts with a more algebraic focus.
Indigenous Sámi Literature
Authors: Ahvenjärvi Kaisa
Published: September 2023

Sámi literature is multilingual, transnational indigenous literature from Northern Fenno-Scandia. It is published in several Sámi languages as well as in majority languages of the Sámi area, which is located in the northern parts of Sweden, Finland, Norway, and Russia. With approximately twenty thousand speakers, North Sámi is the most widely spoken and literarily used of the nine Sámi languages. Considering the limited readership, Sámi literature is exceptionally diverse and vital in the global field of indigenous literatures. The majority of Sámi authors write in their own indigenous language, whereas the majority of Maori, Aboriginal, and Native American literatures, for example, are published in English. Sámi literature has been translated into Nordic languages as well as into bigger world languages like English and Spanish.

Sámi literature has its roots in the oral tradition. The first printed books written by Sámi authors were published at the beginning of the 1900s. However, it was not until the 1970s that Sámi literary institutions were established and the number of publications started to increase. Some key Sámi writers, who started their career then, are Nils-Aslak Valkeapää, Rauni Magga Lukkari, and Kirste Paltto. In the 1980s and 1990s, the novel was the dominating genre in Sámi literature, whereas in the 2000s poetry has flourished. Since the beginning of the 21st century, two-thirds of literature published in Sámi languages is children’s literature.

In Sámi literature there are several common features with other indigenous literatures, both in their historical developments and contemporary characteristics. The breakthrough of indigenous literatures was connected with the global indigenous movement that arose in the 1960s and 1970s, and it was characterized by anticolonial and identity-political themes. Recurring themes in contemporary Sámi and other indigenous literatures are, for example, the questions of hybrid ethnic and linguistic identities, ecological concerns and the interdependency between humans and nature, and the relationship to previous generations and the land. The 2010s have seen a return to political orientation in Sámi art and literature, but universal topics like motherhood and sexuality are also discussed in contemporary Sámi poetry and prose.
Perceptions of the Childfree
Authors: Hintz Elizabeth A. , Tucker Rachel
Published: September 2023

Being voluntarily childless (i.e., “childfree”) is a growing trend in the United States and around the world. Although most childfree people know early in life that they do not wish to become parents, the decision to forgo having children is an ongoing process that requires childfree people to construct a life that deviates from the normative family life cycle. Increasing rates of voluntary childlessness is a trend spurred by a variety of shifting social, economic, and environmental factors. Yet despite the increasing normalcy of voluntary childlessness, childfree people (and especially childfree women) face social sanctions for deciding not to become parents, being broadly perceived more negatively than childless people (who do not have children but want them) and parents. Such sanctions include social confrontations in which others (e.g., family members) question or contest the legitimacy of their childfree identity. Media coverage of voluntary childlessness forwards the notion that motherhood and femininity are inseparable and that voluntary childlessness is an issue that primarily concerns and affects women. Furthermore, childfree people face discrimination in health care contexts when seeking voluntary sterilization and in workplace contexts when “family-friendly” policies create unequal distributions of labor for those without children. Members of the childfree community use the Internet to share resources and seek support to navigate challenging interactions with outsiders. Beyond this, although some studies have begun to interrogate the roles of geographic location, race, and sexual orientation in shaping the experience of voluntary childlessness, at present, a largely White, wealthy, able-bodied, cisgender, heteronormative, and Western view of this topic is still perpetuated in the literature.
University Social Responsibility
Authors: Vargas Vergara Montserrat
Published: September 2023

University social responsibility is an approach that goes beyond understanding the university as a transmitter of content and the training of future professionals. As an institution, it has a social mission: to positively transform and promote the social, economic and environmental development. It draws on the morality, ethics and responsibility of the entire university community to promote a culture and awareness of evaluation and self-assessment. It is a holistic vision that helps to design structures and governance, training and transfer plans, which enable and allow the development and active participation of all members of the society towards which it is projected.
Refugees in East Africa
Authors: Tague Joanna
Published: September 2023

The history of refugees and displaced persons in East Africa is extraordinarily complex. It is a history made all the more complicated by changes in humanitarian law in the mid-20th century pertaining to how the international community defined a “refugee” and what kinds of rights and protections refugee status conferred upon the displaced. There were certainly significant refugee flows in East Africa throughout the many centuries leading up to the mid-20th century, but the sizes of those refugee populations pale in comparison to many of the refugee crises in East Africa since the second half of the 20th century. Whereas in 1964 there were an estimated four hundred thousand refugees on the African continent, by 2019 there were approximately 6.6 million—the second-highest number of displaced persons in the world. Of that number, the vast majority of refugees either came from or sought refuge in East Africa. Five conflicts in particular have produced massive, protracted refugee situations for the region: the Mozambican Civil War, the 1983 famine in Ethiopia, the Somali Civil War, the Great Lakes Refugee Crisis (which includes the Rwandan genocide), and the civil wars in Sudan.
The Economic Benefits of Education for the Reduction of Crime
Authors: Carr Joel , Marie Olivier , Vujić Sunčica
Published: September 2023

Historically, social observers have repeatedly noted a correlation between education and crime, observing that individuals with lower levels of education are more likely to commit crime. However, the relationship between education and crime is complex, and it is important to clearly establish causality to determine if investing in education can effectively reduce crime. Merely observing persistent educational-attainment inequalities between offenders and non-offenders is not sufficient to make any causal claims about the underlying relationship between education and crime. Many other factors can influence an individual’s decision to stay in school or commit a crime, and these factors need to be accounted for when estimating the relationship between education and crime. Economists theoretically predicted in the late 1960s that education, via its positive effect on future earnings, would reduce the probability of criminal participation. Empirical studies have since used various econometric methods to establish that, on average, education has a strong causal crime-reducing effect. One strand of this literature has established in various contexts that individuals from cohorts forced by law to stay longer in school were much less likely to end up in court or prison. There is, however, still much to be discovered about the effect of education on crime, such as the underlying mechanisms related to income or non-cognitive effects, and heterogeneities by context, education level and quality, and individual characteristics. Overall, economists widely agree that investing in education is an efficient public-spending strategy to effectively reduce crime.
Archaeologies of Gender and Childhood in South Asia
Authors: Varma Supriya , Menon Jaya
Published: September 2023

While some studies have been undertaken on childhood in South Asia, there is no focused archaeological study on any aspect of gender in this region. Hence, information has been culled from work that only tangentially refers to aspects of gender. Within the constraints at hand, themes of gender and childhood in South Asia can be explored from studies on representation, production, toys, and skeletal remains. For instance, age, gender, masculinity, identity, and status have been deciphered through anthropomorphic representations. Similarly, can women’s work be discerned by looking at the locations of production, or the presence of children through toys? Skeletal data have pointed the way toward an understanding of matrilocality, migration, stress, and trauma that may have impacted women and children.

In South Asian archaeology, there has been a focus on artifacts and their production and on classification and typology, often at times to the exclusion of the people who would have been associated with these objects. If people are at all considered, it is always with the assumption that men were the active agents in production, with women undertaking primarily domestic chores, like cooking. The bulk of craft production appears to have taken place in household contexts, where women and children, as also the aged, would equally have been active producers. There are tantalizing glimpses of what can be archaeologies of gender and childhood in South Asia, where certain social groups experienced more stress and trauma than other groups, pointing toward social stratification in the Indus period. Similarly, in the medieval period, differential representations can give hints for gender and status relations among communities. However, much more work focusing on these themes needs to be done in this region. To get more nuanced and deeper insights into gender and childhood, questions around these themes need to be formulated and integrated into archaeological projects.
Christian Zionism in the United States, 1930–2020
Authors: Durbin Sean
Published: September 2023

Christian Zionism is a term that is predominantly associated with theologically conservative Christians who believe that the modern nation state of Israel is the fulfillment of biblical prophecy. Contemporary Christian Zionists believe that Israel’s creation in 1948, its expansion in 1967, and its flourishing are all evidence that God continues to have a special relationship with the Jewish people. Consequently, Christian Zionists assert that it is their duty as Christians to support and protect Israel, which they see as a logical extension of their evangelical identity. This support takes the form of political lobbying and providing financial support through donations, tourism, other activities in the United States and Israel. For many, the belief that God still has a special relationship with Israel also includes an emphasis on eschatology, or the end times, and the belief that Israel’s establishment is part of a series of events that will lead to large-scale war, leading to the battle of Armageddon and the return of Jesus. In the United States, there have been varying levels of politically active support for Israel from theologically diverse Christians. However, after 1967 the base of Christian Zionism in the United States was consolidated among theologically conservative evangelicals who viewed Israel in prophetic terms and interpreted events in Israel through that theological lens. Beginning in the 1970s and continuing into the 21st century, the politically active base of Christian Zionism became increasingly defined by the most conservative elements of American evangelicalism and the Christian Right. Christian Zionists were among the fiercest critics of the Obama administration, whom they argued was putting Israel in existential danger and, therefore, inviting divine punishment on the United States. Conversely, Christian Zionists, as a subset of evangelicals, were among Donald Trump’s biggest supporters, and through his Administration they achieved many of their political aspirations such as moving the United States Embassy in Israel from Tel Aviv to Jerusalem and withdrawing from the Iran nuclear deal.