bluuebunny/crossref_metadata_2025 huggingface dataset:
Synergistic effect of a diatomic boron-doped layered two-dimensional MSi2N4 monolayer for an efficient electrochemical nitrogen reduction
Authors: Dang Qian , Zhang Yuqin , Wang Xiaohang , Liu Tianyong , Zhang Mingjie , Li Xingxing , Guo Wei , Tang Shaobin , Jiang Jun
Published: June 2022

A diatomic boron-doped two-dimensional MSi2N4 monolayer (M = transition metal) can boost electrochemical N2 reduction to NH3 with high activity due to the synergistic effect of adjacent boron atoms, both thermodynamically and kinetically.
Highly water-dispersible PCN nanosheets as light-controlled lysosome self-promoting escape type non-cationic gene carriers for tumor therapy
Authors: Liu Ming-Xuan , Zhang Xiao-Ling , Yang Jing-Bo , Lu Zhong-Lin , Zhang Qi-Tao
Published: June 2022

Water-soluble PCN nanosheets were applied to light-controlled self-escaping gene delivery for the first time, and tumor gene therapy was successfully realized.
Towards ‘end-to-end’ analysis and understanding of biological timecourse data
Authors: Jena Siddhartha G. , Goglia Alexander G. , Engelhardt Barbara E.
Published: June 2022

Petabytes of increasingly complex and multidimensional live cell and tissue imaging data are generated every year. These videos hold large promise for understanding biology at a deep and fundamental level, as they capture single-cell and multicellular events occurring over time and space. However, the current modalities for analysis and mining of these data are scattered and user-specific, preventing more unified analyses from being performed over different datasets and obscuring possible scientific insights. Here, we propose a unified pipeline for storage, segmentation, analysis, and statistical parametrization of live cell imaging datasets.
Using genomics to understand the mechanisms of virulence and drug resistance in fungal pathogens
Authors: Schikora-Tamarit Miquel Àngel , Gabaldón Toni
Published: June 2022

Fungal pathogens pose an increasingly worrying threat to human health, food security and ecosystem diversity. To tackle fungal infections and improve current diagnostic and therapeutic tools it is necessary to understand virulence and antifungal drug resistance mechanisms in diverse species. Recent advances in genomics approaches have provided a suitable framework to understand these phenotypes, which ultimately depend on genetically encoded determinants. In this work, we review how the study of genome sequences has been key to ascertain the bases of virulence and drug resistance traits. We focus on the contribution of comparative genomics, population genomics and directed evolution studies. In addition, we discuss how different types of genomic mutations (small or structural variants) contribute to intraspecific differences in virulence or drug resistance. Finally, we review current challenges in the field and anticipate future directions to solve them. In summary, this work provides a short overview of how genomics can be used to understand virulence and drug resistance in fungal pathogens.
A self‐contained self‐protected ±70 V voltage‐to‐current converter with ±0.2% non‐linearity
Authors: Xiao Zhiming , Zhai Dengfu , Yang Junzhong , Yang Sen , Wu Weiguo , Hu Weibo , Luo Feng
Published: June 2022

This paper presents a self‐protected wide‐range bi‐directional voltage‐to‐current (V–I) converter. The proposed V–I converter is a self‐contained cell that operates independently and implements high precision conversion with a transconductance set by resistors. Compared with conventional structures, the proposed scheme features safety and reliability. The conversion range is widened since the internal biasing current is not starved and is adaptively set based on the input voltage. The proposed V–I structure was fabricated in a 0.18‐µm Bipolar‐CMOS‐DMOS (BCD) process with a die area of 0.0825 mm2. The measured non‐linearity across an input voltage range from −70 to 70 V was within ±0.2%. The total harmonic distortion was −63 dB at 1 kHz and the delay of conversion was within 3 µs.
Analytical modelling of one cage rotor induction motor for electric submersible pumps
Authors: Rezaee‐Alam Farhad , Nazari Marashi Abbas , Dehafarin Abolfazl , Kanzi Khalil , Roozbehani Sam
Published: June 2022

A new hybrid analytical model (HAM) based on conformal mapping (CM) method and magnetic equivalent circuit (MEC) model is presented in this paper for electromagnetic modelling of cage rotor induction motors (CRIMs) used in electric submersible pumps (ESPs). For every operating point, the iron parts are modelled with a non‐linear MEC model to calculate the equivalent virtual currents, which represent the influence of magneto motive force (MMF) drops and MMF sources in stator and rotor cores. The effects of the equivalent virtual currents on the air‐gap magnetic field are then considered using the CM method and Hague's solution. This approach for calculating the air‐gap field is also used to prepare a 3‐D lookup table (3‐D LUT) for each element of inductance matrix and derivative of inductance matrix in terms of rotor position. These LUTs are then used for transient modelling and analysis of CRIM under no‐load and loading conditions. The accuracy of proposed HAM is validated by comparing the results obtained through HAM with corresponding results obtained from finite element method and experiment set‐up.
Gravitoturbulent dynamo in global simulations of gaseous disks
Authors: Béthune William , Latter Henrik
Published: June 2022

Context. The turbulence driven by gravitational instabilities (GIs) can amplify magnetic fields in massive gaseous disks. This GI dynamo may appear in young circumstellar disks, whose weak ionization challenges other amplification routes, as well as in active galactic nuclei. Although regarded as a large-scale dynamo, only local simulations have so far described its kinematic regime.

Aims. We study the GI dynamo in global magnetohydrodynamic (MHD) models of accretion disks, focusing on its kinematic phase.

Methods. We perform resistive MHD simulations with the PLUTO code for different radiative cooling times and electrical resistivities. A weak magnetic field seeds the dynamo, and we adopt mean-field and heuristic models to capture its essence.

Results. We recover the same induction process leading to magnetic field amplification as previously identified in local simulations. The dynamo is, however, global in nature, connecting distant annuli of the disk via a large-scale dynamo mode of a fixed growth rate. This large-scale amplification can be described by a mean-field model that does not rely on conventional α-Ω effects. When varying the disk parameters we find an optimal resistivity that facilitates magnetic amplification, whose magnetic Reynolds number, ℛm ≲ 10, is substantially smaller than in local simulations. Unlike local simulations, we find an optimal cooling rate and the existence of global oscillating dynamo modes. The nonlinear saturation of the dynamo puts the disk in a strongly magnetized turbulent state on the margins of the effective range of GI. In our simulations, the accretion power eventually exceeds the threshold required by local thermal balance against cooling, leaving the long-term nonlinear outcome of the GI dynamo uncertain.
The interstellar medium of high-redshift galaxies: Gathering clues from C III] and [C II] lines
Authors: Markov V. , Carniani S. , Vallini L. , Ferrara A. , Pallottini A. , Maiolino R. , Gallerani S. , Pentericci L.
Published: June 2022

Context.A tight relation between [C II] 158 μm line luminosity and the star formation rate (SFR) has been observed for local galaxies. At high redshift (z > 5), galaxies instead deviate downwards from the local Σ[C II]− ΣSFRrelation. This deviation might be caused by different interstellar medium (ISM) properties in galaxies at early epochs.

Aims.To test this hypothesis, we combined the [C II] and SFR data with C III] 1909 Å line observations and our physical models. We additionally investigated how ISM properties, such as burstiness,κs, total gas density,n, and metallicity,Z, affect the deviation from the Σ[C II]− ΣSFRrelation in these sources.

Methods.We present the VLT/X-shooter observations targeting the C III]λ1909 line emission in three galaxies at 5.5 < z < 7.0. We include archival X-shooter data of two other sources at 5.5 < z < 7.0 and the VLT/MUSE archival data of six galaxies atz ∼ 2. We extend our sample of galaxies with eleven star-forming systems at 6 < z < 7.5, with either C III] or [C II] detection reported in the literature.

Results.We detected C III]λλ1907, 1909 line emission in HZ10 and we derived the intrinsic, integrated flux of the C III]λ1909 line. We constrained the ISM properties for our sample of galaxies,κs,n, andZ, by applying our physically motivated model based on the MCMC algorithm. For the most part, high-zstar-forming galaxies show subsolar metallicities. The majority of the sources have log(κs) ≳ 1, that is, they overshoot the Kennicutt–Schmidt (KS) relation by about one order of magnitude.

Conclusions.Our findings suggest that the whole KS relation might be shifted upwards at early times. Furthermore, all the high-zgalaxies of our sample lie below the Σ[C II]− ΣSFRlocal relation. The total gas density,n, shows the strongest correlation with the deviation from the local Σ[C II]− ΣSFRrelation, namely, low-density high-zsystems have lower [C II] surface brightness, in agreement with theoretical models.
Wideband Acoustic Absorbance in Otosclerosis: Does Stapedotomy Restore Normal Tympanic Cavity Function?*
Authors: Durante Alessandra Spada , Nascimento Polyana Cristiane , Almeida Katia de , Servilha Thamyris Rosati , Marçal Gil Junqueira , Neto Osmar Mesquita de Sousa
Published: June 2022

Introduction Otosclerosis is characterized by the fixation of the stapes to the oval window, thereby impairing acoustic signal absorbance. A commonly used surgical technique for improving hearing in cases of otosclerosis is stapedotomy. However, it is unclear whether this surgery restores all the physical characteristics of the tympano-ossicular system.

Objective To evaluate the tympano-ossicular system in individuals with fenestral otosclerosis pre and poststapedotomy using wideband tympanometry.

Method A total of 47 individuals and 71 ears were assessed. The subjects were divided into three groups: presurgery otosclerosis; postsurgery; and a control group of normal-hearing adults. A handheld tympanometer with a wideband module (226–8,000 Hz) was used to take measurements at ambient pressure and under pressurized conditions. The level of statistical significance adopted was p ≤ 0.05.

Results Acoustic absorbance at 226 Hz was low for all groups. At frequencies in the range 630 to 5,040 Hz, each group had a characteristic absorbance curve, allowing them to be distinguished from one another. In the presurgery group, absorbance values were below normal levels, with energy absorbance below 10%. Low energy absorbance was most evident at 1,000 Hz in the presurgery group, but this was not observed in the postsurgery group. Although there was an improvement in hearing, the surgery failed to restore the tympano-ossicular system to normal.

Conclusion Wideband acoustic absorbance proved able to differentiate normal ears and otosclerotic ears pre and postsurgery, under both ambient pressure and pressurized conditions.
Standard Fixed Enoxaparin Dosing for Venous Thromboembolism Prophylaxis Leads to Low Peak Anti-Factor Xa Levels in Both Head and Neck and Breast Free Flap Patients
Authors: Ambani Shoshana W. , Bengur Fuat Baris , Varelas Lee J. , Nguyen Vu T. , Cruz Carolyn De La , Acarturk Tahsin Oguz , Manders Ernest K. , Kubik Mark W. , Sridharan Shaum , Gimbel Michael L. , Solari Mario G.
Published: June 2022

Background Venous thromboembolism (VTE) is a serious complication, particularly in cancer patients undergoing free flap reconstruction. Subcutaneous enoxaparin is the conventional prophylaxis for VTE prevention, and serum anti-factor Xa (afXa) levels are being increasingly used to monitor enoxaparin activity. In this study, free flap patients receiving standard enoxaparin prophylaxis were prospectively followed to investigate postoperative afXa levels and 90-day VTE and bleeding-related complications.

Methods Patients undergoing free tissue transfer during an 8-month period were identified and prospectively followed. Patients received standard fixed enoxaparin dosing at 30 mg twice daily in head and neck (H&N) and 40 mg daily in breast reconstructions. Target peak prophylactic afXa range was 0.2 to 0.5 IU/mL. The primary outcome was the occurrence of 90-day postoperative VTE- and bleeding-related events. Independent predictors of afXa level and VTE incidence were analyzed for patients that met the inclusion criteria.

Results Seventy-eight patients were prospectively followed. Four (5.1%) were diagnosed with VTE, and six (7.7%) experienced bleeding-related complications. The mean afXa levels in both VTE patients and bleeding patients were subprophylactic (0.13 ± 0.09 and 0.11 ± 0.07 IU/mL, respectively). Forty-six patients (21 breast, 25 H&N) had valid postoperative peak steady-state afXa levels. Among these, 15 (33%) patients achieved the target prophylactic range: 5 (33%) H&N and 10 (67%) breast patients. The mean afXa level for H&N patients was significantly lower than for breast patients (p = 0.0021). Patient total body weight was the sole negative predictor of afXa level (R
2 = 0.47, p < 0.0001).

Conclusion Standard fixed enoxaparin dosing for postoperative VTE prophylaxis does not achieve target afXa levels for the majority of our free flap patients. H&N patients appear to be a particularly high-risk group that may require a more personalized and aggressive approach. Total body weight is the sole negative predictor of afXa level, supporting a role for weight-based enoxaparin dosing.
Nosocomial Pneumonia in the Mechanically Ventilated Patient
Authors: Fanning Jonathon , Panigada Mauro , Li Bassi Gianluigi
Published: June 2022

Ventilator-associated pneumonia (VAP) is a common complication occurring in critically ill patients who are mechanically ventilated and is the leading cause of nosocomial infection-related death. Etiologic agents for VAP widely differ based on the population of intensive care unit patients, duration of hospital stay, and prior antimicrobial therapy. VAP due to multidrug-resistant pathogens is associated with the highest morbidity and mortality, likely due to delays in appropriate antimicrobial treatment. International guidelines are currently available to guide diagnostic and therapeutic strategies. VAP can be prevented through various pharmacological and non-pharmacological interventions, which are more effective when grouped as bundles. When VAP is clinically suspected, diagnostic strategies should include early collection of respiratory samples to guide antimicrobial therapy. Empirical treatment should be based on the most likely etiologic microorganisms and antibiotics likely to be active against these microorganisms. Response to therapy should be reassessed after 3 to 5 days and antimicrobials adjusted or de-escalated to reduce the burden of the disease. Finally, considering that drug resistance is increasing worldwide, several novel antibiotics are being tested to efficiently treat VAP in the coming decades.
Computational fluid dynamics used to model heat transfer within lungs
Authors: Green Leigh Ann
Published: June 2022

Lung geometry based on computerized tomography data may be crucial for avoiding alveolar injuries
Virgin effect in spheres of LaFeSi-based alloys
Authors: Bahl Christian R. H. , Liang Jierong , Masche Marvin , Nielsen Kaspar K. , Engelbrecht Kurt
Published: June 2022

A virgin phase transition is observed in spherical particles of the industrially relevant magnetocaloric material La(Fe,Mn,Si)13Hy. Upon initial cooling, the phase transition is observed 2–3 K below the heating transition on all subsequent cooling and heating transitions. This virgin transition has been studied using differential scanning calorimetry and vibrating sample magnetometry. Incremental measurements show not only how the phase transition can be carefully approached but also that the initial full transformation requires cooling of about 6 K below the observed phase transformation. No signs of structural damage due to the thermal cycling were observed, neither macroscopically or by scanning electron microscopy.
Research on the characteristics of the leeward vortex flow field on a blunt-headed rotating body at high angles of attack
Authors: Wang Jian , Wang Xiao , Jiang Kun , Song Daquan
Published: June 2022

Detached eddy simulation was used to numerically compute the leeward vortex flow field on a blunt-headed rotating body. The effects of changes in the angle of attack and flight velocity on the evolutionary law of the counter-rotating vortexes and the fluctuation characteristics of the lateral force coefficient were analyzed. The results show that the counter-rotating vortexes on the leeward surface of the blunt-headed rotating body gradually separate from the wall along the direction from the tail to the head of the projectile as the angle of attack increases. In addition, it shows a periodic variation law of alternating expansion and detachment of the unilateral separated vortex. When the angle of attack is greater than 30°, the fluctuation amplitude of the lateral force coefficient initially rises and then drops with an increase in the angle of attack, while the fluctuation frequency keeps increasing. The maximum amplitude and corresponding frequency of the lateral force coefficient under the main fluctuation remain in the range of 100–230 Hz and have a linear positive feedback relationship with the flight Mach number. With the angle of attack and flight velocity as independent variables, the fittings were performed on the varying laws of maximum amplitude and the corresponding frequency of the lateral force coefficient under the main fluctuation. An unsteady calculation equation for the lateral force coefficient under the change in coupling with the angle of attack and flight velocity was established.
Step-wise constant-amplitude waves in non-Hermitian disordered media
Authors: Zhang Haixiao , Zhang Yiwei , Liu Xiaoli , Bao Yu , Zhao Jinyu
Published: June 2022

Multi-reflection interference of sound waves is ubiquitous in our daily life, and suppressing any such distortions of a wave’s free propagation and achieving counter-directional adaptation is a challenging task, with many applications in acoustics. Here, we propose a non-Hermitian Fabry–Perot resonance unit, which demonstrates unidirectional invisibility in opposite directions at the so-called exceptional points by adjusting its geometric configuration and intrinsic acoustic parameters. Then, we extend the principle and design a waveguide containing six inclusion–membrane pairs in which a unique property of step-wise constant-amplitude waves in two opposite directions has been realized, irrespective of whether the distribution of inclusions is periodic or random. Our method breaks through the limitation of the impedance, amount, position of the inclusions, and the incident direction of the waves, revealing potential applications in acoustic sensing, noise control engineering, and other related wave disciplines.
Approach to select optimal cross-correlation parameters for light field particle image velocimetry
Authors: Zhu Xiaoyu , Xu Chuanlong , Hossain Md. Moinul , Li Jian , Zhang Biao , Khoo Boo Cheong
Published: June 2022

The light field particle image velocimetry (LF-PIV) has shown great potential for three-dimensional (3D) flow measurement in space-constrained applications. Usually, the parameters of the cross correlation calculation in the LF-PIV are chosen based on empirical analysis or introduced from conventional planar PIV, which lowers the accuracy of 3D velocity field measurement. This study presents an approach to selecting optimal parameters of the cross correlation calculation and thereby offers systematic guidelines for experiments. The selection criterion of the interrogation volume size is studied based on the analysis of the valid detection probability of the correlation peak. The optimal seeding concentration and the size of tracer particles are then explored through synthetic Gaussian vortex field reconstruction. The optimized parameters are employed in a cylinder wake flow measurement in a confined channel. A comparative study is conducted between the LF-PIV and a planar PIV system. Results indicate that the LF-PIV along with the optimized parameters can measure the 3D flow velocity of the cylinder wakes accurately. It has been observed that the mean and max errors of velocity decrease by 32.6% and 18.8%, respectively, compared to the related LF-PIV techniques without consideration of optimal parameters. Therefore, it is suggested that the optimized cross correlation parameters in the LF-PIV can improve the accuracy of 3D flow measurement.
Hybrid analytical method for calibrating a standard NaI(Tl) gamma-ray scintillation detector using a lateral hexagonal radioactive source
Authors: Badawi Mohamed S. , Hamzawy A. , Thabet Abouzeid A.
Published: June 2022

In various fields of radiation and nuclear physics, research and its applications help in the management and control of human activities, especially in the analysis of nuclear waste and measurement of low activity environmental samples. The current study uses a hybrid analytical technique and a 152Eu lateral hexagonal radioactive source to calibrate a standard cylindrical NaI(Tl) γ-ray scintillation detector. The technique is a combination of experimental measurements and theoretical calculations because for each environmental and/or radioactive waste sample, a separate reference calibration source equivalent to samples of different compositions is required, which needs additional funding. This method is suitable for any source–detector geometry. It can be used to calculate the geometric, total, and full-energy peak efficiency and the P/T ratio using the model probability of detecting γ-radiation photons, in particular from a lateral hexagonal radioactive source. The detection probability can be mainly influenced by the direction of the γ-quantum motion. This can help build more realistic and complex models than the typical point source case, where simple integration is used to numerically calculate the efficiency of the detection system. Using this method, the self-attenuation and coincidence-summing effect can be calculated for any gamma source matrices. The results obtained can show how useful this technique can be for calibrating complex gamma-ray detectors with any type of gamma-ray source.
Book Review
Authors: Recher Harry F.
Published: June 2022

This review looks critically at the way the status of species is assessed. The current approach based on IUCN criteria is reactive when it should be proactive and include species that have or are increasing in abundance. Nonetheless, the 2020 Action Plan is an important report and will be used to promote the conservation of Australian birds.
Drag-free control design and in-orbit validation of TianQin-1 satellite
Authors: Xiao Chunyu , Bai Yanzheng , Li Hongyin , Liu Li , Liu Yanchong , Luo Jun , Ma Yun , Qu Shaobo , Tan Dingyin , Wang Chengrui , Wu Shuchao , Yin Hang , Yu Jianbo , Zhou Annan , Zhou Zebing
Published: June 2022

Drag-free control (DFC) is one of the key technologies for space-borne gravitational wave detectors. For the TianQin (TQ) project, non-gravitational disturbances on the spacecraft must be suppressed by DFC. TianQin-1 (TQ-1) is the first satellite for technology verification, whose main goal is to verify the disturbances reduction technologies. In this paper, the DFC requirement and preliminary analysis for the TQ project are introduced, and then the design and the experimental validation with the TQ-1 satellite is presented. In-orbit results show a successful validation of DFC and the residual acceleration of TQ-1 satellite has been suppressed to

5
×
1

0

−
11

m

s

−
2

H

z

−
1
/
2

at 10 mHz versus

2
×
1

0

−
9

m

s

−
2

H

z

−
1
/
2

thruster noise.
Huygens’ cycloidal pendulum: an elementary derivation
Authors: Borghi Riccardo
Published: June 2022

A pedagogical derivation of the Huygens cycloidal pendulum, suitable for undergraduates, is here presented. Our derivation rests only on simple algebraic and geometrical tricks, without the need of Calculus.
Giant exchange bias in antiferromagnetic Pr2CoFe0.5Mn0.5O6: a structural and magnetic properties study
Authors: Anand Khyati , Pal Arkadeb , Joshi Amish G , Pal Prabir , Singh Rahul , Yen Peter Tsung-Wen , Huang S M , Alam Md , Kumari Seema , Sathe Vasant , Chakravarty Sujoy , Mohan Anita , Chatterjee Sandip
Published: June 2022

Antiferromagnetic (AFM) materials with a colossal exchange bias (EB) effect find applications as high-density spintronic devices. We report structural (geometrical and electronic) and magnetic studies in the polycrystalline Pr2CoFe0.5Mn0.5O6 double perovskite system. The observed lack of training effect suggests the existence of robust EB. In addition, the detailed magnetic studies and Raman studies unravel the Griffith-like phase along with the spin-phonon coupling in the present system. The x-ray photoemission spectroscopy (XPS) analysis supports more than one valence state of B-site elements, which is accountable for the competition between ferromagnetic (FM) and AFM interactions in addition to the anti-site disorder in the system. The neutron measurement confirms the G-type AFM spin arrangement, accredited by the DFT calculation. The magnetic studies have correlated with the electronic structure, neutron study, and theoretical first principle calculations.
Step-flow growth of Al droplet free AlN epilayers grown by plasma assisted molecular beam epitaxy
Authors: Shao Pengfei , Li Siqi , Li Zhenhua , Zhou Hui , Zhang Dongqi , Tao Tao , Yan Yu , Xie Zili , Wang Ke , Chen Dunjun , Liu Bin , Zheng Youdou , Zhang Rong , Lin Tsungtse , Wang Li , Hirayama Hideki
Published: June 2022

We have investigated an Al modulation epitaxy (AME) method to obtain step-flow growth of Al droplet free AlN layers by plasma assisted molecular beam epitaxy (MBE). At the usual growth temperature of (Al)GaN/AlN heterostructures, Al atom migration and desorption rate are very low and consequently it is very difficult to avoid the formation of Al droplets on AlN growth front by conventional MBE growth method. By adopting the AME growth method, such a difficulty has been effectively overcome and step flow growth mode of AlN has been clearly observed. By optimizing the AME growth time sequence, namely, AlN growth time and N radical beam treatment time, Al droplet free AlN layers with step flow growth characteristics have been obtained, with atomic flat surfaces and an average atomic step width of ∼118 nm at 970 °C–1000 °C, which is still suitable to grow (Al)GaN/AlN heterostructures by MBE.
Machine-learned model Hamiltonian and strength of spin–orbit interaction in strained Mg2X (X = Si, Ge, Sn, Pb)
Authors: Alidoust Mohammad , Rothmund Erling , Akola Jaakko
Published: June 2022

Machine-learned multi-orbital tight-binding (MMTB) Hamiltonian models have been developed to describe the electronic characteristics of intermetallic compounds Mg2Si, Mg2Ge, Mg2Sn, and Mg2Pb subject to strain. The MMTB models incorporate spin–orbital mediated interactions and they are calibrated to the electronic band structures calculated via density functional theory by a massively parallelized multi-dimensional Monte-Carlo search algorithm. The results show that a machine-learned five-band tight-binding (TB) model reproduces the key aspects of the valence band structures in the entire Brillouin zone. The five-band model reveals that compressive strain localizes the contribution of the 3s orbital of Mg to the conduction bands and the outer shell p orbitals of X (X = Si, Ge, Sn, Pb) to the valence bands. In contrast, tensile strain has a reversed effect as it weakens the contribution of the 3s orbital of Mg and the outer shell p orbitals of X to the conduction bands and valence bands, respectively. The π bonding in the Mg2X compounds is negligible compared to the σ bonding components, which follow the hierarchy

|

σ

s
p

|

>

|

σ

p
p

|

>

|

σ

s
s

|

, and the largest variation against strain belongs to σ

pp
. The five-band model allows for estimating the strength of spin–orbit coupling (SOC) in Mg2X and obtaining its dependence on the atomic number of X and strain. Further, the band structure calculations demonstrate a significant band gap tuning and band splitting due to strain. A compressive strain of

−
10
%

can open a band gap at the Γ point in metallic Mg2Pb, whereas a tensile strain of

+
10
%

closes the semiconducting band gap of Mg2Si. A tensile strain of

+
5
%

removes the three-fold degeneracy of valence bands at the Γ point in semiconducting Mg2Ge. The presented MMTB models can be extended for various materials and simulations (band structure, transport, classical molecular dynamics), and the obtained results can help in designing devices made of Mg2X.
Particle filter underwater terrain-aided navigation based on gradient fitting
Authors: Zhou Tian , Wang Tianhao , Gao Jiaqi , Guo Qijia , Yan Zhenyu
Published: June 2022

Inertial navigation systems (INSs) are widely used for autonomous underwater vehicle navigation, with excellent short-term precision. However, the positioning error of an INS accumulates with time. It is imperative to adopt other approaches to mitigate drift errors, especially for long-term sailing tasks. To that end, underwater terrain-based navigation (TBN) is effective in bounding the drift errors. In particular, the particle filtering (PF) method is extensively employed in TBN to tackle the highly nonlinear measurement equation. In our previous work, the statistical properties of the digital terrain model gradient were exploited and we proposed the use of three probability density functions to characterize the normalized data, i.e. Gaussian, gamma and Weibull distributions. In this paper, the likelihood was modified according to the gradient fitting results, i.e. an optimal distribution selection. Moreover, to prevent the measurement data with large gradients from generating particles with lower weights, a pre-screen procedure was proposed to stabilize particle filter sampling. As shown and demonstrated in simulations, our proposed improved PF method outperforms the comparative ones in terms of root mean square error and standard deviation, as well as accuracy, especially for long-term sailing tasks. In terms of computational cost, a smaller number of measurement data are employed and the proposed method is faster than the standard PF method.
Circular arc pendulum: experiment and motion’s analysis
Authors: El-Tawargy Ahmed S , Ramadan Wael A
Published: June 2022

In this work, a simple rocking pendulum, in a circular arc shape, is presented. The idea is to put a rigid arc on a clean flat surface of glass and leave it to oscillate under the effect of a little impulse. Then, the periodic time of this arc pendulum’s motion is experimentally determined. The mathematical analysis of the arc’s motion is derived based on the principle of the energy conservation. The arc’s motion is found to be expressed by an equation of a simple harmonic motion. It is found that the motion’s periodic time depends on the gravitational acceleration, arc’s radius of curvature, the arc’s central angle and the arc’s thickness. Nine rigid circular arcs having the same radius of curvature and thicknesses, but are different in the central geometrical angle, are used to experimentally verify the proposed model. The measured and the calculated periodic times of all of them are in a good agreement. The dependence of the periodic time of the oscillating arc on its radius, thickness and central angle is illustrated. In spite of its simplicity and easiness of realisation, this experiment offers demonstration of a good example of rocking sensation and experimental verification of the calculated arc’s moment of inertia.
TOPAS-nBio simulation of temperature-dependent indirect DNA strand break yields
Authors: Ramos-Méndez José , García-García Omar , Domínguez-Kondo Jorge , LaVerne Jay A , Schuemann Jan , Moreno-Barbosa Eduardo , Faddegon Bruce
Published: June 2022

Current Monte Carlo simulations of DNA damage have been reported only at ambient temperature. The aim of this work is to use TOPAS-nBio to simulate the yields of DNA single-strand breaks (SSBs) and double-strand breaks (DSBs) produced in plasmids under low-LET irradiation incorporating the effect of the temperature changes in the environment. A new feature was implemented in TOPAS-nBio to incorporate reaction rates used in the simulation of the chemical stage of water radiolysis as a function of temperature. The implemented feature was verified by simulating temperature-dependent G-values of chemical species in liquid water from 20 °C to 90 °C. For radiobiology applications, temperature dependent SSB and DSB yields were calculated from 0 °C to 42 °C, the range of available published measured data. For that, supercoiled DNA plasmids dissolved in aerated solutions containing EDTA irradiated by Cobalt-60 gamma-rays were simulated. TOPAS-nBio well reproduced published temperature-dependent G-values in liquid water and the yields of SSB and DSB for the temperature range considered. For strand break simulations, the model shows that the yield of SSB and DSB increased linearly with the temperature at a rate of (2.94 ± 0.17) × 10−10 Gy–1 Da–1 °C–1 (R
2 = 0.99) and (0.13 ± 0.01) × 10−10 Gy–1 Da–1 °C–1 (R
2 = 0.99), respectively. The extended capability of TOPAS-nBio is a complementary tool to simulate realistic conditions for a large range of environmental temperatures, allowing refined investigations of the biological effects of radiation.
Heteroepitaxial β-Ga2O3 thick films on sapphire substrate by carbothermal reduction rapid growth method
Authors: Zhang Wenhui , Zhang Hezhi , Zhang Zhenzhong , Zhang Qi , Hu Xibing , Liang Hongwei
Published: June 2022

The heteroepitaxial β-Ga2O3 thick films were rapidly grown on various oriented sapphire substrates using carbothermal reduction method. The β-Ga2O3 films were prepared in our home-made vertical dual temperature zone furnace. The growth direction as well as surface morphology showed the strong dependence on the orientation of the sapphire substrate. The fastest growth rate was obtained reaching approximate 15 μm h−1 on c-plane sapphire substrate according to the average 30 μm thickness of β-Ga2O3 films grown for 2 h measured by cross-section scanning electron microscope. The Raman spectra indicated the pure-phase β-Ga2O3 films without obvious strain. The bandgap for grown films were in range of 4.6–4.7 eV confirmed by x-ray photoelectron spectra and Tauc plot from absorption spectra. Secondary ion mass spectrometry was used to check the impurities indicating a limited amount of residual carbon inside the films even though graphite as the reducing agent. The results in this work give promising alternative method of rapid epitaxial β-Ga2O3 thick films for the application on high-power electronic devices.
Dynamical analysis of a new chaotic system and its application in ADC
Authors: Shen Yupeng , Bai Yu , Zou Tao , Zhang Lei , Su Yanrui , Wu Zhao , Liu Haiwen , Yan Fabao
Published: June 2022

The improvement of Analog-to-Digital Converter (ADC) performance is crucial to improve the data quality of the signal acquisition system. Therefore, based on the dithering technology, combined with the chaotic system, the study designs and analyses a novel method to improve the Spurious-Free dynamic range (SFDR) of the ADC. First, a new five-dimensional chaotic system is proposed in this paper. The chaotic characteristics and dynamic behavior of the new system have been deeply analysed. The analysis methods mainly consist of the Lyapunov exponent, bifurcation diagram, power spectrum and sample entropy. The corresponding simulation model has been developed in Simulink, and the simulation results prove the reality and feasibility of the new chaotic system. Second, the random number homogenization universal algorithm is used to modify the amplitude of the chaotic sequences generated by the new chaotic system. The uniformity and correlation analysis prove that the Dither signal has strong uniformity and randomness. Third, a behaviour-level simulation model of the pipeline ADC is built; then, the narrowband, broadband and different amplitude Dither signals are added to verify the improvement effect for the dynamic performance of the ADC. The experimental results demonstrate that the designed method can improve the SFDR of the ADC by 10.37 dBc, which effectively eliminates the harmonic energy and improves the dynamic performance of the ADC.
Graph-combinatorial approach for large deviations of Markov chains
Authors: Carugno Giorgio , Vivo Pierpaolo , Coghi Francesco
Published: June 2022

We consider discrete-time Markov chains and study large deviations of the pair empirical occupation measure, which is useful to compute fluctuations of pure-additive and jump-type observables. We provide an exact expression for the finite-time moment generating function, which is split in cycles and paths contributions, and scaled cumulant generating function of the pair empirical occupation measure via a graph-combinatorial approach. The expression obtained allows us to give a physical interpretation of interaction and entropic terms, and of the Lagrange multipliers, and may serve as a starting point for sub-leading asymptotics. We illustrate the use of the method for a simple two-state Markov chain.
Affinity capture of escherichia coli pathotypes using poly-L-lysine functionalized silver nanoparticles
Authors: Daramola Oluwafemi Bamidele , Torimiro Nkem , Alayande Samson Oluwagbemiga
Published: June 2022

In this study, optical detection of different pathotypes of diarrhoeagenic Escherichia coli (E. coli) was exploited using biosynthesized silver nanoparticles (AgNPs) poly-coated with Poly-L-lysine hydrobromide (PLL) and monitored at 540 nm wavelength. A colour change from reddish-brown to colourless (with brown precipitates) with different absorbance values was obtained for each pathotype within two hours of interaction. The bio-affinity sensing and selective adhesion of poly-coated AgNPs (PLL-AgNPs) and E. coli strains were best observed in Enteroaggregative E. coli (0.067 ± 0.004) and Shiga toxin E. coli (0.070 ± 0.002). Slight differences in the negatively charged O-antigen present in E. coli pathotypes informed their varying binding affinity with PLL-AgNPs. Diarrhoeagenic E. coli monitoring using PLL-AgNPs and optical sensing method is a promising approach toward preventing the use of unsafe water and improving public health.
Multi-response optimization in turning of EN-24 steel under MQL
Authors: Thakur Archana , Guleria Vikrant , Lal Roshan
Published: June 2022

Cutting fluids used in manufacturing industry have environmental and economic drawbacks. In order to reduce the negative effects associated with cutting the fluids, it is now becoming indispensable to move towards more sustainable techniques. In this research work, the turning of EN-24 steel under minimum quantity lubrication (MQL) environment have been done. The study has been completed three phases. The first phase deals with planning of experiments based on Box-Behnken design. The influence of input process parameters i.e., cutting speed, feed rate, depth of cut and MQL flow rate have been investigated on output parameters i.e., surface roughness, tool wear, cutting temperature and cutting force. The desirability approach strategy has been used for multi-response optimizationof input parameters in the second phase.The third step deals with analysis of results using SEM, 3D surface graphs and main effect graphs. The confirmation experiments have been carried out to verify the developed model. Experimental results revealed that, the turning performance under high MQL flow rate has been found to be the most effective parameter on mean surface roughness, cutting temperature, tool wear and cutting force.
Explainability for deep learning in mammography image quality assessment
Authors: Amanova N , Martin J , Elster C
Published: June 2022

The application of deep learning has recently been proposed for the assessment of image quality in mammography. It was demonstrated in a proof-of-principle study that the proposed approach can be more efficient than currently applied automated conventional methods. However, in contrast to conventional methods, the deep learning approach has a black-box nature and, before it can be recommended for the routine use, it must be understood more thoroughly. For this purpose, we propose and apply a new explainability method: the oriented, modified integrated gradients (OMIG) method. The design of this method is inspired by the integrated gradientsmethod but adapted considerably to the use case at hand. To further enhance this method, an upsampling technique is developed that produces high-resolution explainability maps for the downsampled data used by the deep learning approach. Comparison with established explainability methods demonstrates that the proposed approach yields substantially more expressive and informative results for our specific use case. Application of the proposed explainability approach generally confirms the validity of the considered deep learning-based mammography image quality assessment (IQA) method. Specifically, it is demonstrated that the predicted image quality is based on a meaningful mapping that makes successful use of certain geometric structures of the images. In addition, the novel explainability method helps us to identify the parts of the employed phantom that have the largest impact on the predicted image quality, and to shed some light on cases in which the trained neural networks fail to work as expected. While tailored to assess a specific approach from deep learning for mammography IQA, the proposed explainability method could also become relevant in other, similar deep learning applications based on high-dimensional images.
The Connes embedding problem: A guided tour
Authors: Goldbring Isaac
Published: June 2022

The Connes embedding problem (CEP) is a problem in the theory of tracial von Neumann algebras and asks whether or not every tracial von Neumann algebra embeds into an ultrapower of the hyperfinite II

1

_1

factor. The CEP has had interactions with a wide variety of areas of mathematics, including

C

∗

\mathrm {C}^*

-algebra theory, geometric group theory, free probability, and noncommutative real algebraic geometry, to name a few. After remaining open for over 40 years, a negative solution was recently obtained as a corollary of a landmark result in quantum complexity theory known as

MIP
∗

=
RE

\operatorname {MIP}^*=\operatorname {RE}

. In these notes, we introduce all of the background material necessary to understand the proof of the negative solution of the CEP from

MIP
∗

=
RE

\operatorname {MIP}^*=\operatorname {RE}

. In fact, we outline two such proofs, one following the “traditional” route that goes via Kirchberg’s QWEP problem in

C

∗

\mathrm {C}^*

-algebra theory and Tsirelson’s problem in quantum information theory and a second that uses basic ideas from logic.
Almost everywhere convergence of spectral sums for self-adjoint operators
Authors: Chen Peng , Duong Xuan Thinh , Yan Lixin
Published: June 2022

Let

L
L

be a non-negative self-adjoint operator acting on the space

L
2

(
X
)

L^2(X)

, where

X
X

is a positive measure space. Let

L

=

∫
0

∞

λ
d

E

L

(

λ

)

{ L}=\int _0^{\infty } \lambda dE_{ L}({\lambda })

be the spectral resolution of

L
L

and

S
R

(

L

)
f
=

∫
0
R

d

E

L

(
λ
)
f

S_R({ L})f=\int _0^R dE_{ L}(\lambda ) f

denote the spherical partial sums in terms of the resolution of

L

{ L}

. In this article we give a sufficient condition on

L
L

such that
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="limit Underscript upper R right-arrow normal infinity Endscripts upper S Subscript upper R Baseline left-parenthesis upper L right-parenthesis f left-parenthesis x right-parenthesis equals f left-parenthesis x right-parenthesis comma a period e period">

lim

R
→
∞

S
R

(

L

)
f
(
x
)
=
f
(
x
)
,
 
 
a.e.

\begin{equation*} \lim _{R\rightarrow \infty } S_R({ L})f(x) =f(x),\ \ \text {a.e.} \end{equation*}

for any

f
f

such that

log
⁡
(
2
+
L
)
f
∈

L
2

(
X
)

\operatorname {log}(2+L) f\in L^2(X)

. These results are applicable to large classes of operators including Dirichlet operators on smooth bounded domains, the Hermite operator and Schrödinger operators with inverse square potentials.
Dictatorship and Global Anglophone Fiction
Authors: Leman Peter
Published: June 2022

Authors in the global Anglophone world have long been interested in the phenomenon of dictatorships, often more by necessity than by choice as many of them personally witnessed the horrors of authoritarian rule. Among scholars, increasing attention is being given to dictatorships and the fictions that depict or otherwise respond to them in Anglophone contexts. Africa, in particular, has seen an explosion of literary texts and scholarly output, although there are important contributions from authors in South Asia, the Caribbean, and even the United States. Throughout these texts, which include novels, short fiction, plays, and poetry, authors take the authoritarian and his methods, enemies, and inevitable downfall as their subject. The reasons for doing so vary. Some authors barely veil the inspiration for their fictional leaders, intending to challenge actual dictators, sometimes at great risk and sacrifice. Others use fictional dictatorships to explore issues of sovereignty, neocolonialism, gender inequality, literary form, and more, suggesting the extent to which dictatorships cannot simply be thought of as a “third-world” phenomenon, as many do in the West, but as a problem that has both global implications and, often, global (i.e., colonial and neocolonial) origins.

Whatever their reasons and whatever their narrative approach, writers throughout the Anglophone world and beyond are engaged in a widespread and ongoing conversation about ultimate power and the cultish personalities that strive for it. The growing body of research from the social sciences underscores the diversity of circumstances and factors that give rise to dictatorships in different parts of the world, but the equally diverse fictions also reveal recurring patterns and themes. Nearly every dictator depends deeply on performance and spectacle, for example. They also seek to control their nations by controlling narrative, something writers are particularly equipped to challenge. Dictatorships and the fictions that portray them are also extended meditations on the nature of sovereign power, which dictators believe, and try to prove, to be absolute. This belief and a need for proof are fed by desperation and lead to various forms of personality worship, transcendence, and the dictator’s self-deification. At the same time, dictatorships also employ some of the least transcendent techniques imaginable to control populations (i.e., bureaucracy and red tape). Finally, as dictators discover they are not gods but mortals and even puppets, they are inevitably brought down from their imagined heights by international forces, other aspiring dictators, freedom fighters, and death itself.